National Library of Energy BETA

Sample records for matter ge lt

  1. Beam-Target Double Spin Asymmetry A_LT in Charged Pion Production from Deep Inelastic Scattering on a Transversely Polarized He-3 Target at 1.4GeV^2

    E-Print Network [OSTI]

    J. Huang; K. Allada; C. Dutta; J. Katich; X. Qian; Y. Wang; Y. Zhang; K. Aniol; J. R. M. Annand; T. Averett; F. Benmokhtar; W. Bertozzi; P. C. Bradshaw; P. Bosted; A. Camsonne; M. Canan; G. D. Cates; C. Chen; J. -P. Chen; W. Chen; K. Chirapatpimol; E. Chudakov; E. Cisbani; J. C. Cornejo; F. Cusanno; M. M. Dalton; W. Deconinck; C. W. de Jager; R. De Leo; X. Deng; A. Deur; H. Ding; P. A. M. Dolph; D. Dutta; L. El Fassi; S. Frullani; H. Gao; F. Garibaldi; D. Gaskell; S. Gilad; R. Gilman; O. Glamazdin; S. Golge; L. Guo; D. Hamilton; O. Hansen; D. W. Higinbotham; T. Holmstrom; M. Huang; H. F. Ibrahim; M. Iodice; X. Jiang; G. Jin; M. K. Jones; A. Kelleher; W. Kim; A. Kolarkar; W. Korsch; J. J. LeRose; X. Li; Y. Li; R. Lindgren; N. Liyanage; E. Long; H. -J. Lu; D. J. Margaziotis; P. Markowitz; S. Marrone; D. McNulty; Z. -E. Meziani; R. Michaels; B. Moffit; C. Muñoz Camacho; S. Nanda; A. Narayan; V. Nelyubin; B. Norum; Y. Oh; M. Osipenko; D. Parno; J. C. Peng; S. K. Phillips; M. Posik; A. J. R. Puckett; Y. Qiang; A. Rakhman; R. D. Ransome; S. Riordan; A. Saha; B. Sawatzky; E. Schulte; A. Shahinyan; M. H. Shabestari; S. Širca; S. Stepanyan; R. Subedi; V. Sulkosky; L. -G. Tang; A. Tobias; G. M. Urciuoli; I. Vilardi; K. Wang; B. Wojtsekhowski; X. Yan; H. Yao; Y. Ye; Z. Ye; L. Yuan; X. Zhan; Y. -W. Zhang; B. Zhao; X. Zheng; L. Zhu; X. Zhu; X. Zong; for the Jefferson Lab Hall A Collaboration

    2012-02-10

    We report the first measurement of the double-spin asymmetry $A_{LT}$ for charged pion electroproduction in semi\

  2. GeV-scale dark matter: Production at the Main Injector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dobrescu, Bogdan A.; Frugiuele, Claudia

    2015-02-03

    Assuming that dark matter particles interact with quarks via a GeV-scale mediator, we study dark matter production in fixed target collisions. The ensuing signal in a neutrino near detector consists of neutral-current events with an energy distribution peaked at higher values than the neutrino background. We find that for a Z' boson of mass around a few GeV that decays to dark matter particles, the dark matter beam produced by the Main Injector at Fermilab allows the exploration of a range of values for the gauge coupling that currently satisfy all experimental constraints. The NO?A near detector is well positionedmore »for probing the presence of a dark matter beam, and future LBNF near detectors would provide more sensitive probes.« less

  3. GeV-scale dark matter: Production at the Main Injector

    SciTech Connect (OSTI)

    Dobrescu, Bogdan A.; Frugiuele, Claudia

    2015-02-03

    Assuming that dark matter particles interact with quarks via a GeV-scale mediator, we study dark matter production in fixed target collisions. The ensuing signal in a neutrino near detector consists of neutral-current events with an energy distribution peaked at higher values than the neutrino background. We find that for a Z' boson of mass around a few GeV that decays to dark matter particles, the dark matter beam produced by the Main Injector at Fermilab allows the exploration of a range of values for the gauge coupling that currently satisfy all experimental constraints. The NO?A near detector is well positioned for probing the presence of a dark matter beam, and future LBNF near detectors would provide more sensitive probes.

  4. Higgs-Portal Dark Matter for GeV Gamma-Ray Excess

    E-Print Network [OSTI]

    P. Ko; Wan-Il Park; Yong Tang

    2015-04-27

    We present Higgs-Portal dark matter (DM) models to explain the reported Galactic Center GeV gamma-ray excess. Naive effective theories are inconsistent with direct detection constraint for the relevant parameter range. Simple extended models with dark gauge symmetries can easily accommodate the gamma-ray excess through the Higgs-Portal coupling while satisfying various constraints.

  5. Direct Detection of sub-GeV Dark Matter with Semiconductor Targets

    E-Print Network [OSTI]

    Rouven Essig; Marivi Fernandez-Serra; Jeremy Mardon; Adrian Soto; Tomer Volansky; Tien-Tien Yu

    2015-09-04

    Dark matter in the sub-GeV mass range is a theoretically motivated but largely unexplored paradigm. Such light masses are out of reach for conventional nuclear recoil direct detection experiments, but may be detected through the small ionization signals caused by dark matter-electron scattering. Semiconductors are well-studied and are particularly promising target materials because their ${\\cal O}(1~\\rm{eV})$ band gaps allow for ionization signals from dark matter as light as a few hundred keV. Current direct detection technologies are being adapted for dark matter-electron scattering. In this paper, we provide the theoretical calculations for dark matter-electron scattering rate in semiconductors, overcoming several complications that stem from the many-body nature of the problem. We use density functional theory to numerically calculate the rates for dark matter-electron scattering in silicon and germanium, and estimate the sensitivity for upcoming experiments such as DAMIC and SuperCDMS. We find that the reach for these upcoming experiments has the potential to be orders of magnitude beyond current direct detection constraints and that sub-GeV dark matter has a sizable modulation signal. We also give the first direct detection limits on sub-GeV dark matter from its scattering off electrons in a semiconductor target (silicon) based on published results from DAMIC. We make available publicly our code, QEdark, with which we calculate our results. Our results can be used by experimental collaborations to calculate their own sensitivities based on their specific setup. The searches we propose will probe vast new regions of unexplored dark matter model and parameter space.

  6. Higgs portal, fermionic dark matter, and a Standard Model like Higgs at 125 GeV

    E-Print Network [OSTI]

    Laura Lopez-Honorez; Thomas Schwetz; Jure Zupan

    2012-07-09

    We show that fermionic dark matter (DM) which communicates with the Standard Model (SM) via the Higgs portal is a viable scenario, even if a SM-like Higgs is found at around 125 GeV. Using effective field theory we show that for DM with a mass in the range from about 60 GeV to 2 TeV the Higgs portal needs to be parity violating in order to be in agreement with direct detection searches. For parity conserving interactions we identify two distinct options that remain viable: a resonant Higgs portal, and an indirect Higgs portal. We illustrate both possibilities using a simple renormalizable toy model.

  7. Higgs portal vector dark matter for GeV scale ?-ray excess from galactic center

    SciTech Connect (OSTI)

    Ko, P.; Park, Wan-Il; Tang, Yong E-mail: wipark@kias.re.kr

    2014-09-01

    We show that the GeV scale ?-ray excess from the direction of the Galactic Center can be naturally explained by the pair annihilation of Abelian vector dark matter (VDM) into a pair of dark Higgs bosons (VV? ? ?), followed by the subsequent decay of ? into b b-bar or ? ?-bar  . All the processes are described by a renormalizable VDM model with the Higgs portal, which is naturally flavor-dependent. Some parameter space of this scenario can be tested at the near future direct dark matter search experiments such as LUX and XENON1T.

  8. A 750 GeV Portal: LHC Phenomenology and Dark Matter Candidates

    E-Print Network [OSTI]

    D'Eramo, Francesco; Panci, Paolo

    2016-01-01

    We study the effective field theory obtained by extending the Standard Model field content with two singlets: a 750 GeV (pseudo-)scalar and a stable fermion. Accounting for collider productions initiated by both gluon and photon fusion, we investigate where the theory is consistent with both the LHC diphoton excess and bounds from Run 1. We analyze dark matter phenomenology in such regions, including relic density constraints as well as collider, direct, and indirect bounds. Scalar portal dark matter models are very close to limits from direct detection if gluon fusion dominates, and not constrained at all otherwise. Pseudo-scalar models are challenged by photon line limits in most of the parameter space.

  9. A 750 GeV Portal: LHC Phenomenology and Dark Matter Candidates

    E-Print Network [OSTI]

    Francesco D'Eramo; Jordy de Vries; Paolo Panci

    2016-01-07

    We study the effective field theory obtained by extending the Standard Model field content with two singlets: a 750 GeV (pseudo-)scalar and a stable fermion. Accounting for collider productions initiated by both gluon and photon fusion, we investigate where the theory is consistent with both the LHC diphoton excess and bounds from Run 1. We analyze dark matter phenomenology in such regions, including relic density constraints as well as collider, direct, and indirect bounds. Scalar portal dark matter models are very close to limits from direct detection if gluon fusion dominates, and not constrained at all otherwise. Pseudo-scalar models are challenged by photon line limits in most of the parameter space.

  10. Lt.

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and700, 1.Reports1E~LONG-TERMLetter Reportfor

  11. CONSTRAINING THE DISTRIBUTION OF DARK MATTER IN THE INNER GALAXY WITH AN INDIRECT DETECTION SIGNAL: THE CASE OF A TENTATIVE 130 GeV {gamma}-RAY LINE

    SciTech Connect (OSTI)

    Yang Ruizhi; Feng Lei; Li Xiang; Fan Yizhong

    2013-06-20

    Dark matter distribution in the very inner region of our Galaxy is still debated. In N-body simulations, a cuspy dark matter halo density profile is favored. Several dissipative baryonic processes, however, are found to be able to significantly flatten dark matter distribution, and a cored dark matter halo density profile is possible. Baryons dominate the gravitational potential in the inner Galaxy, hence a direct constraint on the abundance of dark matter particles is rather challenging. Recently, a few groups have identified a tentative 130 GeV line signal in the Galactic center, which could be interpreted as the signal of dark matter annihilation. Using current 130 GeV line data and adopting the generalized Navarro-Frenk-White profile of the dark matter halo-local dark matter density {rho}{sub 0} = 0.4 GeV cm{sup -3} and r{sub s} = 20 kpc-we obtain a 95% confidence level lower (upper) limit on the inner slope of dark matter density distribution, {alpha} = 1.06 (the cross section of dark matter annihilation into {gamma}-rays ({sigma}v){sub {chi}{chi}{sub {yields}{sub {gamma}{gamma}}}} = 1.3 Multiplication-Sign 10{sup -27} cm{sup 3} s{sup -1}). Such a slope is consistent with the results of some N-body simulations and, if the signal is due to dark matter, suggests that baryonic processes may be unimportant.

  12. Electronic and nuclear contributions in sub-GeV dark matter scattering: A case study with hydrogen

    E-Print Network [OSTI]

    Jiunn-Wei Chen; Hsin-Chang Chi; C. -P. Liu; Chih-Liang Wu; Chih-Pan Wu

    2015-08-14

    Scattering of sub-GeV dark matter (DM) particles with hydrogen atoms is studied in this paper. The interactions of DM with electrons and nucleons are both included and formulated in a general framework based on nonrelativistic effective field theory. On the assumption of same dark matter coupling strengths, it is found that DM-electron interactions dominate the inelastic atomic transitions to discrete excited states and ionization continuum around the threshold regions, and DM-nucleon interactions become more important with increasing energy and dominate in elastic scattering. The conclusion should apply, qualitatively, to practical detector species so that electronic and nuclear contributions in DM scattering processes can be disentangled, while issues including binding effects and recoil mechanism in many-body systems will require further detailed calculations.

  13. Electronic and nuclear contributions in sub-GeV dark matter scattering: A case study with hydrogen

    E-Print Network [OSTI]

    Chen, Jiunn-Wei; Liu, C -P; Wu, Chih-Liang; Wu, Chih-Pan

    2015-01-01

    Scattering of sub-GeV dark matter (DM) particles with hydrogen atoms is studied in this paper. The interactions of DM with electrons and nucleons are both included and formulated in a general framework based on nonrelativistic effective field theory. On the assumption of same dark matter coupling strengths, it is found that DM-electron interactions dominate the inelastic atomic transitions to discrete excited states and ionization continuum around the threshold regions, and DM-nucleon interactions become more important with increasing energy and dominate in elastic scattering. The conclusion should apply, qualitatively, to practical detector species so that electronic and nuclear contributions in DM scattering processes can be disentangled, while issues including binding effects and recoil mechanism in many-body systems will require further detailed calculations.

  14. Nuclear matter effects on J/? production in asymmetric Cu+Au collisions at ?SNN=200 GeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Adare, A.

    2014-12-18

    We report on J/? production from asymmetric Cu+Au heavy-ion collisions at ?sNN =200 GeV at the Relativistic Heavy Ion Collider at both forward (Cu-going direction) and backward (Au-going direction) rapidities. The nuclear modification of J/? yields in Cu+Au collisions in the Au-going direction is found to be comparable to that in Au+Au collisions when plotted as a function of the number of participating nucleons. In the Cu-going direction, J/? production shows a stronger suppression. This difference is comparable in magnitude and has the same sign as the difference expected from shadowing effects due to stronger low-x gluon suppression in themore »larger Au nucleus. The relative suppression is opposite to that expected from hot nuclear matter dissociation, since a higher energy density is expected in the Au-going direction.« less

  15. A tale of tails. Dark matter interpretations of the Fermi GeV excess in light of background model systematics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Calore, Francesca; Cholis, Ilias; McCabe, Christopher; Weniger, Christoph

    2015-03-10

    Several groups have identified an extended excess of gamma rays over the modeled foreground and background emissions towards the Galactic center (GC) based on observations with the Fermi Large Area Telescope. This excess emission is compatible in morphology and spectrum with a telltale sign from dark matter (DM) annihilation. Here, we present a critical reassessment of DM interpretations of the GC signal in light of the foreground and background uncertainties that some of us recently outlaid in Calore et al. (2014). We find that a much larger number of DM models fits the gamma-ray data than previously noted. In particular:more »(1) In the case of DM annihilation into b¯b, we find that even large DM masses up to m??74 GeV are allowed at p-value >0.05. (2) Surprisingly, annihilation into nonrelativistic hh gives a good fit to the data. (3) The inverse Compton emission from ?+?– with m? ~ 60–70 GeV can also account for the excess at higher latitudes, |b|>2°, both in its spectrum and morphology. We also present novel constraints on a large number of mixed annihilation channels, including cascade annihilation involving hidden sector mediators. In conclusion, we show that the current limits from dwarf spheroidal observations are not in tension with a DM interpretation when uncertainties on the DM halo profile are accounted for.« less

  16. Light NMSSM Neutralino Dark Matter in the Wake of CDMS II and a 126 GeV Higgs

    E-Print Network [OSTI]

    Kozaczuk, Jonathan

    2013-01-01

    Recent results from the Cryogenic Dark Matter Search (CDMS) experiment have renewed interest in light dark matter with a large spin-independent neutralino-nucleon scattering cross-section. Here, we examine the regions of the NMSSM capable of producing a light neutralino with a large direct detection cross-section, with scattering mediated by a light singlet-like scalar, and a 126 GeV Higgs consistent with the LHC results. We focus on two different scenarios for annihilation in the early universe, namely annihilation mediated by (1) a light scalar or by (2) a light pseudoscalar. We find that there exists viable parameter space in which a very light CP-even Higgs boson mediates both the neutralino-nucleon spin-independent elastic scattering and the neutralino pair-annihilation in the early universe. These regions can feature significant tree-level contributions to the SM-like Higgs mass and hence not require very heavy or highly-mixed stops. The strongest constraints in this case come from the decays of the SM-...

  17. Hurricane Bonnie Assessr;;c;lt

    E-Print Network [OSTI]

    Hurricane Bonnie Assessr;;c;lt Review of Hurricane Evacuation Studies Utilization and Information Dissemination April 1999 USArmy Corps of Engineers #12;HURRICANEBONNIE ASSESSMENT Review ofHurricane;National Oceanic and Atmospheric Administration Weather Bureau Hurricane Series ERRATA NOTICE One or more

  18. The 130 GeV gamma-ray line and generic dark matter model building constraints from continuum gamma rays, radio and antiproton data

    E-Print Network [OSTI]

    Masaki Asano; Torsten Bringmann; Gunter Sigl; Martin Vollmann

    2013-05-16

    An analysis of the Fermi gamma ray space telescope data has recently revealed a resolved gamma-ray feature close to the galactic center which is consistent with monochromatic photons at an energy of about 130 GeV. If interpreted in terms of dark matter (DM) annihilating into \\gamma\\gamma (\\gamma Z, \\gamma h), this would correspond to a DM particle mass of roughly 130 GeV (145 GeV, 155 GeV). The rate for these loop-suppressed processes, however, is larger than typically expected for thermally produced DM. Correspondingly, one would generically expect even larger tree level production rates of standard model fermions or gauge bosons. Here, we quantify this expectation in a rather model-independent way by relating the tree level and loop amplitudes with the help of the optical theorem. As an application, we consider bounds from continuum gamma rays, radio and antiproton data on the tree level amplitudes and translate them into constraints on the loop amplitudes. We find that, independently of the DM production mechanism, any DM model aiming at explaining the line signal in terms of charged standard model particles running in the loop is in rather strong tension with at least one of these constraints, with the exception of loops dominated by top quarks. We stress that attempts to explain the 130 GeV feature with internal bremsstrahlung do not suffer from such difficulties.

  19. Becky Hill Green Mountain DNA Conference LT-DNA Analysis

    E-Print Network [OSTI]

    Becky Hill ­ Green Mountain DNA Conference LT-DNA Analysis July 26, 2010 http of the Chief Medical Examiner, NYC Green Mountain DNA Conference Burlington, VT July 26, 2010 Low Template (LT generally aim for 0.5-2 ng 100 pg template 5 pg template #12;Becky Hill ­ Green Mountain DNA Conference LT

  20. Cold Nuclear Matter Effects on J/Psi as Constrained by Deuteron-Gold Measurements at sqrt(s_NN) = 200 GeV

    E-Print Network [OSTI]

    PHENIX Collaboration; A. Adare

    2007-11-25

    We present a new analysis of J/psi production yields in deuteron-gold collisions at sqrt(s_NN) = 200 GeV using data taken by the PHENIX experiment in 2003 and previously published in [S.S. Adler et al., Phys. Rev. Lett 96, 012304 (2006)]. The high statistics proton-proton J/psi data taken in 2005 is used to improve the baseline measurement and thus construct updated cold nuclear matter modification factors R_dAu. A suppression of J/psi in cold nuclear matter is observed as one goes forward in rapidity (in the deuteron-going direction), corresponding to a region more sensitive to initial state low-x gluons in the gold nucleus. The measured nuclear modification factors are compared to theoretical calculations of nuclear shadowing to which a J/psi (or precursor) break-up cross-section is added. Breakup cross sections of sigma_breakup = 2.8^[+1.7_-1.4] (2.2^[+1.6_-1.5]) mb are obtained by fitting these calculations to the data using two different models of nuclear shadowing. These breakup cross section values are consistent within large uncertainties with the 4.2 +/- 0.5 mb determined at lower collision energies. Projecting this range of cold nuclear matter effects to copper-copper and gold-gold collisions reveals that the current constraints are not sufficient to firmly quantify the additional hot nuclear matter effect.

  1. Nuclear matter effects on J/? production in asymmetric Cu+Au collisions at ?SNN=200 GeV

    SciTech Connect (OSTI)

    Adare, A. [Univ. of Colorado, Boulder, CO (United States)

    2014-12-18

    We report on J/? production from asymmetric Cu+Au heavy-ion collisions at ?sNN =200 GeV at the Relativistic Heavy Ion Collider at both forward (Cu-going direction) and backward (Au-going direction) rapidities. The nuclear modification of J/? yields in Cu+Au collisions in the Au-going direction is found to be comparable to that in Au+Au collisions when plotted as a function of the number of participating nucleons. In the Cu-going direction, J/? production shows a stronger suppression. This difference is comparable in magnitude and has the same sign as the difference expected from shadowing effects due to stronger low-x gluon suppression in the larger Au nucleus. The relative suppression is opposite to that expected from hot nuclear matter dissociation, since a higher energy density is expected in the Au-going direction.

  2. Nuclear matter effects on J/? production in asymmetric Cu + Au collisions at \\(\\sqrt{s_{\\mathrm{NN}}} = 200\\) GeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Alexander, J.; Alfred, M.; Aoki, K.; Apadula, N.; Aramaki, Y.; et al

    2014-12-18

    We report on J/? production from asymmetric Cu+Au heavy-ion collisions at \\(\\sqrt{s_{\\mathrm{NN}}} = 200\\) GeV at the Relativistic Heavy Ion Collider at both forward (Cu-going direction) and backward (Au-going direction) rapidities. The nuclear modification of J/? yields in Cu+Au collisions in the Au-going direction is found to be comparable to that in Au+Au collisions when plotted as a function of the number of participating nucleons. In the Cu-going direction, J/? production shows a stronger suppression. This difference is comparable in magnitude and has the same sign as the difference expected from shadowing effects due to stronger low-x gluon suppression inmore »the larger Au nucleus. Thus, the relative suppression is opposite to that expected from hot nuclear matter dissociation, since a higher energy density is expected in the Au-going direction.« less

  3. Nuclear matter effects on J/? production in asymmetric Cu + Au collisions at \\(\\sqrt{s_{\\mathrm{NN}}} = 200\\) GeV

    SciTech Connect (OSTI)

    Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Alexander, J.; Alfred, M.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Atomssa, E. T.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bai, X.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Bathe, S.; Baublis, V.; Baumann, C.; Baumgart, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Bing, X.; Black, D.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Butsyk, S.; Campbell, S.; Chen, C. -H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Christiansen, P.; Chujo, T.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Cronin, N.; Crossette, N.; Csanád, M.; Csörg?, T.; Datta, A.; Daugherity, M. S.; David, G.; DeBlasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Ding, L.; Dion, A.; Do, J. H.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; D'Orazio, L.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Gainey, K.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, A.; Garishvili, I.; Ge, H.; Giordano, F.; Glenn, A.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gu, Y.; Gunji, T.; Guragain, H.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Han, S. Y.; Hanks, J.; Hasegawa, S.; Hashimoto, K.; Hayano, R.; He, X.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hollis, R. S.; Homma, K.; Hong, B.; Hoshino, T.; Huang, J.; Huang, S.; Ichihara, T.; Ikeda, Y.; Imai, K.; Imazu, Y.; Inaba, M.; Iordanova, A.; Isenhower, D.; Isinhue, A.; Ivanishchev, D.; Jacak, B. V.; Jeon, S. J.; Jezghani, M.; Jia, J.; Jiang, X.; Johnson, B. M.; Joo, E.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kamin, J.; Kanda, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Kawall, D.; Kazantsev, A. V.; Key, J. A.; Khachatryan, V.; Khandai, P. K.; Khanzadeev, A.; Kihara, K.; Kijima, K. M.; Kim, C.; Kim, D. H.; Kim, D. J.; Kim, E. -J.; Kim, H. -J.; Kim, M.; Kim, Y. -J.; Kim, Y. K.; Kistenev, E.; Klatsky, J.; Kleinjan, D.; Kline, P.; Koblesky, T.; Kofarago, M.; Komkov, B.; Koster, J.; Kotchetkov, D.; Kotov, D.; Krizek, F.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, G. H.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, S. H.; Leitch, M. J.; Leitgab, M.; Lewis, B.; Li, X.; Lim, S. H.; Liu, M. X.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Manion, A.; Manko, V. I.; Mannel, E.; Maruyama, T.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Miller, A. J.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Montuenga, P.; Moon, T.; Morrison, D. P.; Moskowitz, M.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Mwai, A.; Nagae, T.; Nagamiya, S.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Netrakanti, P. K.; Nihashi, M.; Niida, T.; Nouicer, R.; Novak, T.; Novitzky, N.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Oide, H.; Okada, K.; Orjuela Koop, J. D.; Oskarsson, A.; Ozaki, H.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, S.; Park, S. K.; Pate, S. F.; Patel, L.; Patel, M.; Peng, J. -C.; Perepelitsa, D. V.; Perera, G. D. N.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Purschke, M. L.; Qu, H.; Rak, J.; Ravinovich, I.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Riveli, N.; Roach, D.; Rolnick, S. D.; Rosati, M.; Rowan, Z.; Rubin, J. G.; Ryu, M. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sako, H.; Samsonov, V.; Sarsour, M.; Sato, S.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seele, J.; Seidl, R.; Sekiguchi, Y.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shaver, A.; Shein, I.; Shibata, T. -A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Singh, B. K.; Singh, C. P.; Singh, V.; Skolnik, M.; Slune?ka, M.; Solano, S.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Soumya, M.; Sourikova, I. V.; Stankus, P. W.; Steinberg, P.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Stone, M. R.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Takahara, A.; Taketani, A.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tennant, E.; Timilsina, A.; Todoroki, T.; Tomášek, M.; Torii, H.; Towell, M.; Towell, R.; Towell, R. S.; Tserruya, I.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Virius, M.; Vrba, V.

    2014-12-18

    We report on J/? production from asymmetric Cu+Au heavy-ion collisions at \\(\\sqrt{s_{\\mathrm{NN}}} = 200\\) GeV at the Relativistic Heavy Ion Collider at both forward (Cu-going direction) and backward (Au-going direction) rapidities. The nuclear modification of J/? yields in Cu+Au collisions in the Au-going direction is found to be comparable to that in Au+Au collisions when plotted as a function of the number of participating nucleons. In the Cu-going direction, J/? production shows a stronger suppression. This difference is comparable in magnitude and has the same sign as the difference expected from shadowing effects due to stronger low-x gluon suppression in the larger Au nucleus. Thus, the relative suppression is opposite to that expected from hot nuclear matter dissociation, since a higher energy density is expected in the Au-going direction.

  4. Approved Module Information for LT2102, 2014/5 Module Title/Name: Inventory Control Module Code: LT2102

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for LT2102, 2014/5 Module Title/Name: Inventory Control Module Code: LT2102 School: Engineering and Applied Science Module Type: Standard Module New Module? No Module Credits: 10 Module Management Information Module Leader Name James Stone Email Address j

  5. Approved Module Information for LT2315, 2014/5 Module Title/Name: Rail Transport Module Code: LT2315

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for LT2315, 2014/5 Module Title/Name: Rail Transport Module Code: LT2315 School: Engineering and Applied Science Module Type: Standard Module New Module? No Module Credits: 10 Module Management Information Module Leader Name P Connor Email Address connorp

  6. Approved Module Information for LT1312, 2014/5 Module Title/Name: Literature Review Project Module Code: LT1312

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for LT1312, 2014/5 Module Title/Name: Literature Review Project Module Code: LT1312 School: Engineering and Applied Science Module Type: Standard Module New Module? No Module Credits: 10 Module Management Information Module Leader Name David Carpenter Email Address d

  7. Approved Module Information for LT1307, 2014/5 Module Title/Name: Principles of Economics Module Code: LT1307

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for LT1307, 2014/5 Module Title/Name: Principles of Economics Module Code: LT1307 School: Engineering and Applied Science Module Type: Standard Module New Module? No Module Credits: 10 Module Management Information Module Leader Name David Carpenter Email Address d

  8. Approved Module Information for LT1319, 2014/5 Module Title/Name: Air Transport Module Code: LT1319

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for LT1319, 2014/5 Module Title/Name: Air Transport Module Code: LT1319 School: Engineering and Applied Science Module Type: Standard Module New Module? No Module Credits: 10 Module Management Information Module Leader Name James Stone Email Address j.stone@aston.ac.uk Telephone

  9. Approved Module Information for LT3101, 2014/5 Module Title/Name: Inbound Logistics Module Code: LT3101

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for LT3101, 2014/5 Module Title/Name: Inbound Logistics Module Code: LT in which available: BSc Logistics Management. BSc Construction Project Management. Available to Exchange with an understanding of Inbound Logistics theory and management practice. Module Learning Outcomes: * Evaluate

  10. Fits to the Fermi-LAT GeV excess with RH sneutrino dark matter: implications for direct and indirect dark matter searches and the LHC

    E-Print Network [OSTI]

    Cerdeno, D G; Robles, S

    2015-01-01

    We show that the right-handed (RH) sneutrino in the NMSSM can account for the observed excess in the Fermi-LAT spectrum of gamma rays from the Galactic Centre, while fulfilling all the current experimental constraints from the LHC as well as from direct and indirect dark matter searches. We have explored the parameter space of this scenario, computed the gamma ray spectrum for each phenomenologically viable solution and then performed a chi^2 fit to the excess. Unlike previous studies based on model independent interpretations, we have taken into account the full annihilation spectrum, without assuming pure annihilation channels. Furthermore, we have incorporated limits from direct detection experiments, LHC bounds and also the constraints from Fermi-LAT on dwarf spheroidal galaxies (dSphs) and gamma ray spectral lines. In addition, we have estimated the effect of the most recent Fermi-LAT reprocessed data (Pass~8). In general, we obtain good fits to the GCE when the RH sneutrino annihilates mainly into pairs...

  11. Approved Module Information for LT2320, 2014/5 Module Title/Name: Services Marketing Module Code: LT2320

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for LT2320, 2014/5 Module Title/Name: Services Marketing Module Code a knowledge and understanding of the role of services marketing to managing and delivering a transport or logistics service and assess the relevance of a selected transport service marketing topic

  12. Approved Module Information for LT1301, 2014/5 Module Title/Name: Introduction to Logistics Module Code: LT1301

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for LT1301, 2014/5 Module Title/Name: Introduction to Logistics Module in which available: BSc Logistics with Supply Chain Management. BSc Logistics with Purchasing Management. BSc Logistics with Transport Management. Available to Exchange Students? Not Specified Module Learning

  13. Hadronic production of J/[psi] at large [chi][sub F] in 800 GeV p+Cu and p+Be collisions

    SciTech Connect (OSTI)

    Kowitt, M.S.

    1992-12-01

    The differential cross-section d[sigma]/dx[sub F] for J/[psi] production in 800 GeV proton-nucleus collisions has been measured in the kinematic range 0.30 [le] x[sub F] [le] 0.95 and x[sub F] [lt] p[perpendicular] [lt] 5 GeV through the decay mode J/[psi] [yields] [mu][sup +][mu][sup [minus

  14. Study of Interaction of the Heavy Quarks with Nuclear Matter in Cu+Cu at sqrt(s_NN)=200 GeV

    E-Print Network [OSTI]

    Miroslav Krus; for the STAR Collaboration

    2009-01-29

    In this paper we present the study of the azimuthal correlation function of non-photonic electrons with low-pT hadrons produced in Cu+Cu collision at sqrt(s_NN) = 200 GeV measured by STAR experiment at RHIC. Possible modification of the awayside peak is observed.

  15. Approved Module Information for LT2F04, 2014/5 Module Title/Name: Inventory Module Code: LT2F04

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Approved Module Information for LT2F04, 2014/5 Module Title/Name: Inventory Module Code: LT2F04 School: Engineering and Applied Science Module Type: Foundation New Module? No Module Credits: 20 Module Management Information Module Leader Name Constant Iannacci Email Address c.iannacci@aston.ac.uk Telephone

  16. Approved Module Information for LT1F05, 2014/5 Module Title/Name: Legal and Environmental Aspects Module Code: LT1F05

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Approved Module Information for LT1F05, 2014/5 Module Title/Name: Legal and Environmental Aspects Module Code: LT1F05 School: Engineering and Applied Science Module Type: Foundation New Module? No Module Credits: 20 Module Management Information Module Leader Name Constant Iannacci Email Address c

  17. Approved Module Information for LT2F09, 2014/5 Module Title/Name: Data Analysis Module Code: LT2F09

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Approved Module Information for LT2F09, 2014/5 Module Title/Name: Data Analysis Module Code: LT2F09 School: Engineering and Applied Science Module Type: Standard Module New Module? No Module Credits: 10 Module Management Information Module Leader Name Constant Iannacci Email Address c

  18. Approved Module Information for LT2F05, 2014/5 Module Title/Name: Sourcing and Procurement Module Code: LT2F05

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Approved Module Information for LT2F05, 2014/5 Module Title/Name: Sourcing and Procurement Module Code: LT2F05 School: Engineering and Applied Science Module Type: Foundation New Module? No Module Credits: 20 Module Management Information Module Leader Name Constant Iannacci Email Address c

  19. Approved Module Information for LT2F06, 2014/5 Module Title/Name: Retail Logistics Module Code: LT2F06

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Approved Module Information for LT2F06, 2014/5 Module Title/Name: Retail Logistics Module Code: LT2F06 School: Engineering and Applied Science Module Type: Foundation New Module? No Module Credits: 20 Module Management Information Module Leader Name Constant Iannacci Email Address c

  20. Approved Module Information for LT1F04, 2014/5 Module Title/Name: Warehousing Module Code: LT1F04

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Approved Module Information for LT1F04, 2014/5 Module Title/Name: Warehousing Module Code: LT1F04 School: Engineering and Applied Science Module Type: Foundation New Module? No Module Credits: 20 Module Management Information Module Leader Name Constant Iannacci Email Address c.iannacci@aston.ac.uk Telephone

  1. Approved Module Information for LT2F08, 2014/5 Module Title/Name: Management Accounting Module Code: LT2F08

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Approved Module Information for LT2F08, 2014/5 Module Title/Name: Management Accounting Module Code: LT2F08 School: Engineering and Applied Science Module Type: Standard Module New Module? No Module Credits: 10 Module Management Information Module Leader Name Constant Iannacci Email Address c

  2. Cold-nuclear-matter effects on heavy-quark production at forward and backward rapidity in d+Au collisions at sqrt(s_NN)=200 GeV

    E-Print Network [OSTI]

    A. Adare; C. Aidala; N. N. Ajitanand; Y. Akiba; R. Akimoto; H. Al-Bataineh; H. Al-Ta'ani; J. Alexander; K. R. Andrews; A. Angerami; K. Aoki; N. Apadula; E. Appelt; Y. Aramaki; R. Armendariz; E. C. Aschenauer; E. T. Atomssa; R. Averbeck; T. C. Awes; B. Azmoun; V. Babintsev; M. Bai; G. Baksay; L. Baksay; B. Bannier; K. N. Barish; B. Bassalleck; A. T. Basye; S. Bathe; V. Baublis; C. Baumann; A. Bazilevsky; S. Belikov; R. Belmont; J. Ben-Benjamin; R. Bennett; J. H. Bhom; D. S. Blau; J. S. Bok; K. Boyle; M. L. Brooks; D. Broxmeyer; H. Buesching; V. Bumazhnov; G. Bunce; S. Butsyk; S. Campbell; A. Caringi; P. Castera; C. -H. Chen; C. Y. Chi; M. Chiu; I. J. Choi; J. B. Choi; R. K. Choudhury; P. Christiansen; T. Chujo; P. Chung; O. Chvala; V. Cianciolo; Z. Citron; B. A. Cole; Z. Conesa del Valle; M. Connors; M. Csanád; T. Csörg?; T. Dahms; S. Dairaku; I. Danchev; K. Das; A. Datta; G. David; M. K. Dayananda; A. Denisov; A. Deshpande; E. J. Desmond; K. V. Dharmawardane; O. Dietzsch; A. Dion; M. Donadelli; O. Drapier; A. Drees; K. A. Drees; J. M. Durham; A. Durum; D. Dutta; L. D'Orazio; S. Edwards; Y. V. Efremenko; F. Ellinghaus; T. Engelmore; A. Enokizono; H. En'yo; S. Esumi; B. Fadem; D. E. Fields; M. Finger; M. Finger; \\, Jr.; F. Fleuret; S. L. Fokin; Z. Fraenkel; J. E. Frantz; A. Franz; A. D. Frawley; K. Fujiwara; Y. Fukao; T. Fusayasu; C. Gal; I. Garishvili; A. Glenn; H. Gong; X. Gong; M. Gonin; Y. Goto; R. Granier de Cassagnac; N. Grau; S. V. Greene; G. Grim; M. Grosse Perdekamp; T. Gunji; L. Guo; H. -Å. Gustafsson; J. S. Haggerty; K. I. Hahn; H. Hamagaki; J. Hamblen; R. Han; J. Hanks; C. Harper; K. Hashimoto; E. Haslum; R. Hayano; X. He; M. Heffner; T. K. Hemmick; T. Hester; J. C. Hill; M. Hohlmann; R. S. Hollis; W. Holzmann; K. Homma; B. Hong; T. Horaguchi; Y. Hori; D. Hornback; S. Huang; T. Ichihara; R. Ichimiya; H. Iinuma; Y. Ikeda; K. Imai; M. Inaba; A. Iordanova; D. Isenhower; M. Ishihara; M. Issah; D. Ivanischev; Y. Iwanaga; B. V. Jacak; J. Jia; X. Jiang; J. Jin; D. John; B. M. Johnson; T. Jones; K. S. Joo; D. Jouan; D. S. Jumper; F. Kajihara; J. Kamin; S. Kaneti; B. H. Kang; J. H. Kang; J. S. Kang; J. Kapustinsky; K. Karatsu; M. Kasai; D. Kawall; M. Kawashima; A. V. Kazantsev; T. Kempel; A. Khanzadeev; K. M. Kijima; J. Kikuchi; A. Kim; B. I. Kim; D. J. Kim; E. -J. Kim; Y. -J. Kim; Y. K. Kim; E. Kinney; Á. Kiss; E. Kistenev; D. Kleinjan; P. Kline; L. Kochenda; B. Komkov; M. Konno; J. Koster; D. Kotov; A. Král; A. Kravitz; G. J. Kunde; K. Kurita; M. Kurosawa; Y. Kwon; G. S. Kyle; R. Lacey; Y. S. Lai; J. G. Lajoie; A. Lebedev; D. M. Lee; J. Lee; K. B. Lee; K. S. Lee; S. H. Lee; S. R. Lee; M. J. Leitch; M. A. L. Leite; X. Li; P. Lichtenwalner; P. Liebing; S. H. Lim; L. A. Linden Levy; T. Liška; H. Liu; M. X. Liu; B. Love; D. Lynch; C. F. Maguire; Y. I. Makdisi; M. D. Malik; A. Manion; V. I. Manko; E. Mannel; Y. Mao; H. Masui; F. Matathias; M. McCumber; P. L. McGaughey; D. McGlinchey; C. McKinney; N. Means; M. Mendoza; B. Meredith; Y. Miake; T. Mibe; A. C. Mignerey; K. Miki; A. Milov; J. T. Mitchell; Y. Miyachi; A. K. Mohanty; H. J. Moon; Y. Morino; A. Morreale; D. P. Morrison; S. Motschwiller; T. V. Moukhanova; T. Murakami; J. Murata; S. Nagamiya; J. L. Nagle; M. Naglis; M. I. Nagy; I. Nakagawa; Y. Nakamiya; K. R. Nakamura; T. Nakamura; K. Nakano; S. Nam; J. Newby; M. Nguyen; M. Nihashi; R. Nouicer; A. S. Nyanin; C. Oakley; E. O'Brien; S. X. Oda; C. A. Ogilvie; M. Oka; K. Okada; Y. Onuki; A. Oskarsson; M. Ouchida; K. Ozawa; R. Pak; V. Pantuev; V. Papavassiliou; B. H. Park; I. H. Park; S. K. Park; W. J. Park; S. F. Pate; L. Patel; H. Pei; J. -C. Peng; H. Pereira; D. Yu. Peressounko; R. Petti; C. Pinkenburg; R. P. Pisani; M. Proissl; M. L. Purschke; H. Qu; J. Rak; I. Ravinovich; K. F. Read; S. Rembeczki; K. Reygers; V. Riabov; Y. Riabov; E. Richardson; D. Roach; G. Roche; S. D. Rolnick; M. Rosati; C. A. Rosen; S. S. E. Rosendahl; P. Ruži?ka; B. Sahlmueller; N. Saito; T. Sakaguchi; K. Sakashita; V. Samsonov; S. Sano; M. Sarsour; T. Sato; M. Savastio; S. Sawada; K. Sedgwick; J. Seele; R. Seidl; R. Seto; D. Sharma; I. Shein; T. -A. Shibata; K. Shigaki; H. H. Shim; M. Shimomura; K. Shoji; P. Shukla; A. Sickles; C. L. Silva; D. Silvermyr; C. Silvestre; K. S. Sim; B. K. Singh; C. P. Singh; V. Singh; M. Slune?ka; T. Sodre; R. A. Soltz; W. E. Sondheim; S. P. Sorensen; I. V. Sourikova; P. W. Stankus; E. Stenlund; S. P. Stoll; T. Sugitate; A. Sukhanov; J. Sun; J. Sziklai; E. M. Takagui; A. Takahara; A. Taketani; R. Tanabe; Y. Tanaka; S. Taneja; K. Tanida; M. J. Tannenbaum; S. Tarafdar; A. Taranenko; E. Tennant; H. Themann; D. Thomas; T. L. Thomas; M. Togawa; A. Toia; L. Tomášek; M. Tomášek; H. Torii; R. S. Towell; I. Tserruya; Y. Tsuchimoto; K. Utsunomiya; C. Vale; H. Valle; H. W. van Hecke; E. Vazquez-Zambrano; A. Veicht; J. Velkovska; R. Vértesi; M. Virius; A. Vossen; V. Vrba; E. Vznuzdaev

    2013-10-03

    The PHENIX experiment has measured open heavy-flavor production via semileptonic decay muons over the transverse momentum range 1 < pT < 6 GeV/c at forward and backward rapidity (1.4 < |y| < 2.0) in d+Au and p+p collisions at ?sNN = 200 GeV. In central d+Au collisions an enhancement (suppression) of heavy-flavor muon production is observed at backward (forward) rapidity relative to the yield in p+p collisions scaled by the number of binary collisions. Modification of the gluon density distribution in the Au nucleus contributes in terms of anti-shadowing enhancement and shadowing suppression; however, the enhancement seen at backward rapidity exceeds expectations from this effect alone. These results, implying an important role for additional cold nuclear matter effects, serves as a key baseline for heavy-quark measurements in A+A collisions and in constraining the magnitude of charmonia breakup effects at the Relativistic Heavy Ion Collider and the Large Hadron Collider.

  3. Diffusion in SiGe and Ge

    E-Print Network [OSTI]

    Liao, Christopher Yuan Ting

    2010-01-01

    Claeys, et al. , "Si versus Ge for future microelectronics,"in Selectively Doped Si/Si x Ge 1-x Superlattices," PhysicalA. Fitzgerald, et al. , "Relaxed Ge x Si 1-x structures for

  4. GE's Digital Marketplace to Revolutionize Manufacturing | GE...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    an open online space for companies to collaborate and transform how they design and manufacture their products in the future NISKAYUNA, NY, June 2, 2015 - GE (NYSE:GE), a leading...

  5. Module Information for LT1F01, 2015/6 -APPROVED Module Title/Name: Introduction to Logistics Module Code: LT1F01

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Module Information for LT1F01, 2015/6 - APPROVED Module Title/Name: Introduction to Logistics: Cert He/Level 4 (Enhanced Honours) Programmes in which available: Foundation Degree in Logistics of the general principles of logistics as relevant to a wide range of different sectors for both manufacturing

  6. Approved Module Information for LT1F01, 2014/5 Module Title/Name: Introduction to Logistics Module Code: LT1F01

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Approved Module Information for LT1F01, 2014/5 Module Title/Name: Introduction to Logistics Module in which available: Foundation Degree in Logistics. Available to Exchange Students? No Module Learning Information Module Aims: To give an understanding of the general principles of logistics as relevant to a wide

  7. Approved Module Information for LT2319, 2014/5 Module Title/Name: International Logistics and Purchasing Module Code: LT2319

    E-Print Network [OSTI]

    Neirotti, Juan Pablo

    Approved Module Information for LT2319, 2014/5 Module Title/Name: International Logistics-of-the-art strategic understanding of international logistics and purchasing with an emphasis on global competition. The topics include latest trends in globalization and international trade, major international logistics

  8. Transverse momentum and centrality dependence of dihadron correlations in Au plus Au collisions at root s(NN)=200 GeV: Jet quenching and the response of partonic matter 

    E-Print Network [OSTI]

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Al-Jamel, A.; Aoki, K.; Aphecetche, L.; Armendariz, R.; Aronson, S. H.; Asai, J.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Baksay, G.; Baksay, L.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Bathe, S.; Batsouli, S.; Baublis, V.; Bauer, F.; Bazilevsky, A.; Belikov, S.; Bennett, R.; Berdnikov, Y.; Bickley, A. A.; Bjorndal, M. T.; Boissevain, J. G.; Borel, H.; Boyle, K.; Brooks, M. L.; Brown, D. S.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Campbell, S.; Chai, J. -S; Chang, B. S.; Charvet, J. -L; Chernichenko, S.; Chiba, J.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Chujo, T.; Chung, P.; Churyn, A.; Cianciolo, V.; Cleven, C. R.; Cobigo, Y.; Cole, B. A.; Comets, M. P.; Constantin, P.; Csanad, M.; Csoergo, T.; Dahms, T.; Das, K.; David, G.; Deaton, M. B.; Dehmelt, K.; Delagrange, H.; Denisov, A.; d'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drachenberg, J. L.; Drapier, O.; Drees, A.; Dubey, A. K.; Durum, A.; Dzhordzhadze, V.; Efremenko, Y. V.; Egdemir, J.; Ellinghaus, F.; Emam, W. S.; Enokizono, A.; En'yo, H.; Espagnon, B.; Esumi, S.; Eyser, K. O.; Fields, D. E.; Finger, M.; Finger, M., Jr.; Fleuret, F.; Fokin, S. L.; Forestier, B.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fung, S. -Y; Fusayasu, T.; Gadrat, S.; Garishvili, I.; Gastineau, F.; Germain, M.; Glenn, A.; Gong, H.; Gonin, M.; Gosset, J.; Goto, Y.; de Cassagnac, R. Granier; Grau, N.; Greene, S. V.; Perdekamp, M. Grosse; Gunji, T.; Gustafsson, H. -A; Hachiya, T.; Hadj Henni, A.; Haegemann, C.; Haggerty, J. S.; Hagiwara, M. N.; Hamagaki, H.; Han, R.; Harada, H.; Hartouni, E. P.; Haruna, K.; Harvey, M.; Haslum, E.; Hasuko, K.; Hayano, R.; Heffner, M.; Hemmick, T. K.; Hester, T.; Heuser, J. M.; He, X.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Hohlmann, M.; Holmes, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Hur, M. G.; Ichihara, T.; Imai, K.; Inaba, M.; Inoue, Y.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Jacak, B. V.; Jia, J.; Jin, J.; Jinnouchi, O.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kaneta, M.; Kang, J. H.; Kanou, H.; Kawagishi, T.; Kawall, D.; Kazantsev, A. V.; Kelly, S.; Khanzadeev, A.; Kikuchi, J.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, Y. -S; Kinney, E.; Kiss, A.; Kistenev, E.; Kiyomichi, A.; Klay, J.; Klein-Boesing, C.; Kochenda, L.; Kochetkov, V.; Komkov, B.; Konno, M.; Kotchetkov, D.; Kozlov, A.; Kral, A.; Kravitz, A.; Kroon, P. J.; Kubart, J.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. -S; Lajoie, J. G.; Lebedev, A.; Le Bornec, Y.; Leckey, S.; Lee, D. M.; Lee, M. K.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Lenzi, B.; Lim, H.; Liska, T.; Litvinenko, A.; Liu, M. X.; Li, X.; Li, X. H.; Love, B.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mao, Y.; Masek, L.; Masui, H.; Matathias, F.; McCain, M. C.; McCumber, M.; McGaughey, P. L.; Miake, Y.; Mikes, P.; Miki, K.; Miller, T. E.; Milov, A.; Mioduszewski, Saskia; Mishra, G. C.; Mishra, M.; Mitchell, J. T.; Mitrovski, M.; Morreale, A.; Morrison, D. P.; Moss, J. M.; Moukhanova, T. V.; Mukhopadhyay, D.; Murata, J.; Nagamiya, S.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nakagawa, I.; Nakamiya, Y.; Nakamura, T.; Nakano, K.; Newby, J.; Nguyen, M.; Norman, B. E.; Nyanin, A. S.; Nystrand, J.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Ohnishi, H.; Ojha, I. D.; Okada, H.; Okada, K.; Oka, M.; Omiwade, O. O.; Oskarsson, A.; Otterlund, I.; Ouchida, M.; Ozawa, K.; Pak, R.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, J.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J. -C; Pereira, H.; Peresedov, V.; Peressounko, D. Yu; Pinkenburg, C.; Pisani, R. P.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Roche, G.; Romana, A.; Rosati, M.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Rykov, V. L.; Ryu, S. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakata, H.; Samsonov, V.; Sato, H. D.; Sato, S.; Sawada, S.; Seele, J.; Seidl, R.; Semenov, V.; Seto, R.; Sharma, D.; Shea, T. K.; Shein, I.; Shevel, A.; Shibata, T. -A; Shigaki, K.; Shimomura, M.; Shohjoh, T.; Shoji, K.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, C. P.; Singh, V.; Skutnik, S.; Slunecka, M.; Smith, W. C.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.

    2008-01-01

    The results of midrapidity (0 < y < 0.8) neutral pion spectra over an extended transverse momentum range (1 < p(T) < 12 GeV/c) in root s(NN) = 200 GeV Au + Au collisions, measured by the STAR experiment, are presented. The ...

  9. A community effort towards a knowledge-base and mathematical model of the human pathogen Salmonella Typhimurium LT2

    E-Print Network [OSTI]

    2011-01-01

    of antibiotic-resistant Salmonella typhimurium. Proceedings119. 3. Ohl ME, Miller SI: Salmonella: a model for bacterialcarbon or nitrogen for Salmonella typhimurium LT-2. Journal

  10. Gravitational collapse and non-self similarity in the L-T relation

    E-Print Network [OSTI]

    A. Del Popolo

    2006-09-06

    We derive the luminosity-temperature relation for clusters of galaxies by means of a modification of the self-similar model to take account of angular momentum acquisition by protostructures and of an external pressure term in the virial theorem. The fundamental result of the model is that gravitational collapse, which takes account of angular momentum acquisition, can explain the non self-similarity in the L-T relation, in disagreement with the largely accepted assumption that heating/cooling processes and similar are fundamental in the originating the non-self similar behavior (shaping) of the L-T relation.

  11. Energy Cost Calculator for Commercial Heat Pumps (5.4 >=&lt; 20 Tons) |

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n cEnergy (AZ,LocalEfficiency |&lt; Back Eligibility&lt; BackDepartment

  12. CHEM 114 GE 124 MATH 110 GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    2006-07 CHEM 114 GE 124 MATH 110 GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 GE 210 MATH 223CE 212 CMPT 116 Hum/SocSci Jr. GEOE 218 CE 225 MATH 224GE 213# GE 348# CE 295 English 11x# CE 315 CE 311

  13. Combining LT codes and XOR network coding for reliable and energy efficient transmissions in

    E-Print Network [OSTI]

    Jaffrès-Runser, Katia

    Combining LT codes and XOR network coding for reliable and energy efficient transmissions the problem of providing end to end reliable transmissions in a randomly deployed wireless sensor network or several sink nodes. Due to the large scale of such networks, the transmission is multi-hop between

  14. 12/5/00 LT502X3 E-pure Cartridge

    E-Print Network [OSTI]

    Raizada, Manish N.

    12/5/00 LT502X3 E-pure Cartridge Replacement Instructions For Cartridge Kits WARNING Ensure release when system is pressurized. CAUTION Pretreatment cartridge (D0835 or D0836) must be rinsed in system by itself to avoid plugging of other purification cartridges. Remove 0.2 micron hollow fiber

  15. Window in the dark matter exclusion limits

    SciTech Connect (OSTI)

    Zaharijas, Gabrijela; Farrar, Glennys R. [Center for Cosmology and Particle Physics, New York University, New York, New York 10003 (United States)

    2005-10-15

    We consider the cross section limits for light dark matter cadnidates (m=0.4 to 10 GeV). We calculate the interaction of dark matter in the crust above underground dark matter detectors and find that in the intermediate cross section range, the energy loss of dark matter is sufficient to fall below the energy threshold of current underground experiments. This implies the existence of a window in the dark matter exclusion limits in the micro-barn range.

  16. Approved Module Information for LT1F02, 2014/5 Module Title/Name: Personal Development and Leading

    E-Print Network [OSTI]

    Rebollo-Neira, Laura

    Approved Module Information for LT1F02, 2014/5 Module Title/Name: Personal Development and Leading People Module Code: LT1F02 School: Engineering and Applied Science Module Type: Foundation New Module? No Module Credits: 20 Module Management Information Module Leader Name Constant Iannacci Email Address c

  17. CHEM 114 GE 124 MATH 110 GE 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    CHEM 114 GE 124 MATH 110 GE 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 ME 227 GE 213# MATH 223 EE 201ME 214 CMPT 116 ME 215 GE 226 MATH 224 Hum/SocSci@# ME 251 ME 229 ME 318 ME 335 ME 313

  18. GE ?????????????????4G?????...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A die containing 400 ohmic MEMS switches, as viewed under a microscope, atop a U.S. dime. This device, made with GE's...

  19. CHEM 114 GE 124 MATH 110 COMM 102GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    CHEM 114 GE 124 MATH 110 COMM 102GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 CMPT 116CHEM 250# MATH 223 EE 201 GE 213 Grp. A elective*CHE 223 Hum/SocSci Jr. MATH 224 English 11x CHE 220CHE 210 CHE

  20. CHEM 114 GE 124 MATH 110 COMM 102GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    CHEM 114 GE 124 MATH 110 COMM 102GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 CMPT 116CHEM 250# MATH 223 EE 201 GE 213 Grp. A elective*CHE 223 HSS@# MATH 224 English 11x CHE 220CHE 210 CHE 323 CHE

  1. Solving the Dark Matter Problem

    ScienceCinema (OSTI)

    Baltz, Ted

    2009-09-01

    Cosmological observations have firmly established that the majority of matter in the universe is of an unknown type, called 'dark matter'. A compelling hypothesis is that the dark matter consists of weakly interacting massive particles (WIMPs) in the mass range around 100 GeV. If the WIMP hypothesis is correct, such particles could be created and studied at accelerators. Furthermore they could be directly detected as the primary component of our galaxy. Solving the dark matter problem requires that the connection be made between the two. We describe some theoretical and experimental avenues that might lead to this connection.

  2. GE Research and Development | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of rare Kaonforsupernovae model (Journal About DOE ButtonFSO HomefeatureGE

  3. GE Global Research Leadership | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFESOpportunities Nuclear Physics (NP)about aMunich, GermanyAbout GE

  4. GE Researcher Discusses Leadership | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFESOpportunities Nuclear Physics (NP)aboutRio de Janeiro,theIsGE

  5. A Window in the Dark Matter Exclusion Limits

    E-Print Network [OSTI]

    Gabrijela Zaharijas; Glennys R. Farrar

    2005-06-28

    We consider the cross section limits for light dark matter candidates ($m=0.4$ to 10 GeV). We calculate the interaction of dark matter in the crust above underground dark matter detectors and find that in the intermediate cross section range, the energy loss of dark matter is sufficient to fall below the energy threshold of current underground experiments. This implies the existence of a window in the dark matter exclusion limits in the micro-barn range.

  6. THE HAWAII INFRARED PARALLAX PROGRAM. I. ULTRACOOL BINARIES AND THE L/T TRANSITION

    SciTech Connect (OSTI)

    Dupuy, Trent J.; Liu, Michael C.

    2012-08-01

    We present the first results from our high-precision infrared (IR) astrometry program at the Canada-France-Hawaii Telescope. We measure parallaxes for 83 ultracool dwarfs (spectral types M6-T9) in 49 systems, with a median uncertainty of 1.1 mas (2.3%) and as good as 0.7 mas (0.8%). We provide the first parallaxes for 48 objects in 29 systems, and for another 27 objects in 17 systems, we significantly improve upon published results, with a median (best) improvement of 1.7 times (5 times). Three systems show astrometric perturbations indicative of orbital motion; two are known binaries (2MASS J0518-2828AB and 2MASS J1404-3159AB) and one is spectrally peculiar (SDSS J0805+4812). In addition, we present here a large set of Keck adaptive optics imaging that more than triples the number of binaries with L6-T5 components that have both multi-band photometry and distances. Our data enable an unprecedented look at the photometric properties of brown dwarfs as they cool through the L/T transition. Going from Almost-Equal-To L8 to Almost-Equal-To T4.5, flux in the Y and J bands increases by Almost-Equal-To 0.7 mag and Almost-Equal-To 0.5 mag, respectively (the Y- and J-band 'bumps'), while flux in the H, K, and L' bands declines monotonically. This wavelength dependence is consistent with cloud clearing over a narrow range of temperature, since condensate opacity is expected to dominate at 1.0-1.3 {mu}m. Interestingly, despite more than doubling the near-IR census of L/T transition objects, we find a conspicuous paucity of objects on the color-magnitude diagram just blueward of the late-L/early-T sequence. This 'L/T gap' occurs at (J - H){sub MKO} 0.1-0.3 mag, (J - K){sub MKO} = 0.0-0.4 mag, and implies that the last phases of cloud evolution occur rapidly. Finally, we provide a comprehensive update to the absolute magnitudes of ultracool dwarfs as a function of spectral type using a combined sample of 314 objects.

  7. Use of a promiscuous, constitutively-active bacterial enhancer-binding protein to define the Ï?54 (RpoN) regulon of Salmonella Typhimurium LT2

    E-Print Network [OSTI]

    2013-01-01

    the ? 54 (RpoN) regulon of Salmonella Typhimurium LT2. BMCregulation in Salmonella typhimurium. Identification of anthat catabolize propionate in Salmonella enterica serovar

  8. Use of a promiscuous, constitutively-active bacterial enhancer-binding protein to define the ?54 (RpoN) regulon of Salmonella Typhimurium LT2

    E-Print Network [OSTI]

    2013-01-01

    the ? 54 (RpoN) regulon of Salmonella Typhimurium LT2. BMCregulation in Salmonella typhimurium. Identification of anthat catabolize propionate in Salmonella enterica serovar

  9. Upsilon (1S+2S+3S) production in d+Au and p+p collisions at sqrt(s_NN)=200 GeV and cold-nuclear matter effects

    E-Print Network [OSTI]

    A. Adare; S. Afanasiev; C. Aidala; N. N. Ajitanand; Y. Akiba; R. Akimoto; H. Al-Bataineh; H. Al-Ta'ani; J. Alexander; K. R. Andrews; A. Angerami; K. Aoki; N. Apadula; L. Aphecetche; E. Appelt; Y. Aramaki; R. Armendariz; J. Asai; E. C. Aschenauer; E. T. Atomssa; R. Averbeck; T. C. Awes; B. Azmoun; V. Babintsev; M. Bai; G. Baksay; L. Baksay; A. Baldisseri; B. Bannier; K. N. Barish; P. D. Barnes; B. Bassalleck; A. T. Basye; S. Bathe; S. Batsouli; V. Baublis; C. Baumann; A. Bazilevsky; S. Belikov; R. Belmont; J. Ben-Benjamin; R. Bennett; A. Berdnikov; Y. Berdnikov; J. H. Bhom; A. A. Bickley; D. S. Blau; J. G. Boissevain; J. S. Bok; H. Borel; K. Boyle; M. L. Brooks; D. Broxmeyer; H. Buesching; V. Bumazhnov; G. Bunce; S. Butsyk; C. M. Camacho; S. Campbell; A. Caringi; P. Castera; B. S. Chang; W. C. Chang; J. -L. Charvet; C. -H. Chen; S. Chernichenko; C. Y. Chi; M. Chiu; I. J. Choi; J. B. Choi; R. K. Choudhury; P. Christiansen; T. Chujo; P. Chung; A. Churyn; O. Chvala; V. Cianciolo; Z. Citron; B. A. Cole; Z. Conesa del Valle; M. Connors; P. Constantin; M. Csanád; T. Csörg?; T. Dahms; S. Dairaku; I. Danchev; K. Das; A. Datta; G. David; M. K. Dayananda; A. Denisov; D. d'Enterria; A. Deshpande; E. J. Desmond; K. V. Dharmawardane; O. Dietzsch; A. Dion; M. Donadelli; O. Drapier; A. Drees; K. A. Drees; A. K. Dubey; J. M. Durham; A. Durum; D. Dutta; V. Dzhordzhadze; L. D'Orazio; S. Edwards; Y. V. Efremenko; F. Ellinghaus; T. Engelmore; A. Enokizono; H. En'yo; S. Esumi; K. O. Eyser; B. Fadem; D. E. Fields; M. Finger; M. Finger Jr; F. Fleuret; S. L. Fokin; Z. Fraenkel; J. E. Frantz; A. Franz; A. D. Frawley; K. Fujiwara; Y. Fukao; T. Fusayasu; I. Garishvili; A. Glenn; H. Gong; X. Gong; M. Gonin; J. Gosset; Y. Goto; R. Granier de Cassagnac; N. Grau; S. V. Greene; G. Grim; M. Grosse Perdekamp; T. Gunji; L. Guo; H. -Å. Gustafsson; A. Hadj Henni; J. S. Haggerty; K. I. Hahn; H. Hamagaki; J. Hamblen; R. Han; J. Hanks; C. Harper; E. P. Hartouni; K. Haruna; K. Hashimoto; E. Haslum; R. Hayano; X. He; M. Heffner; T. K. Hemmick; T. Hester; J. C. Hill; M. Hohlmann; R. S. Hollis; W. Holzmann; K. Homma; B. Hong; T. Horaguchi; Y. Hori; D. Hornback; S. Huang; T. Ichihara; R. Ichimiya; H. Iinuma; Y. Ikeda; K. Imai; J. Imrek; M. Inaba; A. Iordanova; D. Isenhower; M. Ishihara; T. Isobe; M. Issah; A. Isupov; D. Ivanischev; Y. Iwanaga; B. V. Jacak; J. Jia; X. Jiang; J. Jin; D. John; B. M. Johnson; T. Jones; K. S. Joo; D. Jouan; D. S. Jumper; F. Kajihara; S. Kametani; N. Kamihara; J. Kamin; S. Kaneti; B. H. Kang; J. H. Kang; J. S. Kang; J. Kapustinsky; K. Karatsu; M. Kasai; D. Kawall; M. Kawashima; A. V. Kazantsev; T. Kempel; A. Khanzadeev; K. M. Kijima; J. Kikuchi; A. Kim; B. I. Kim; D. H. Kim; D. J. Kim; E. Kim; E. -J. Kim; S. H. Kim; Y. -J. Kim; Y. K. Kim; E. Kinney; K. Kiriluk; Á. Kiss; E. Kistenev; J. Klay; C. Klein-Boesing; D. Kleinjan; P. Kline; L. Kochenda; B. Komkov; M. Konno; J. Koster; D. Kotov; A. Kozlov; A. Král; A. Kravitz; G. J. Kunde; K. Kurita; M. Kurosawa; M. J. Kweon; Y. Kwon; G. S. Kyle; R. Lacey; Y. S. Lai; J. G. Lajoie; D. Layton; A. Lebedev; D. M. Lee; J. Lee; K. B. Lee; K. S. Lee; S. H. Lee; S. R. Lee; T. Lee; M. J. Leitch; M. A. L. Leite; B. Lenzi; X. Li; P. Lichtenwalner; P. Liebing; S. H. Lim; L. A. Linden Levy; T. Liška; A. Litvinenko; H. Liu; M. X. Liu; B. Love; D. Lynch; C. F. Maguire; Y. I. Makdisi; A. Malakhov; M. D. Malik; A. Manion; V. I. Manko; E. Mannel; Y. Mao; L. Mašek; H. Masui; F. Matathias; M. McCumber; P. L. McGaughey; D. McGlinchey; C. McKinney; N. Means; M. Mendoza; B. Meredith; Y. Miake; T. Mibe; A. C. Mignerey; P. Mikeš; K. Miki; A. Milov; M. Mishra; J. T. Mitchell; Y. Miyachi; A. K. Mohanty; H. J. Moon; Y. Morino; A. Morreale; D. P. Morrison; S. Motschwiller; T. V. Moukhanova; D. Mukhopadhyay; T. Murakami; J. Murata; S. Nagamiya; J. L. Nagle; M. Naglis; M. I. Nagy; I. Nakagawa; Y. Nakamiya; K. R. Nakamura; T. Nakamura; K. Nakano; S. Nam; J. Newby; M. Nguyen; M. Nihashi; T. Niita; R. Nouicer; A. S. Nyanin; C. Oakley; E. O'Brien; S. X. Oda; C. A. Ogilvie; M. Oka; K. Okada; Y. Onuki; A. Oskarsson; M. Ouchida; K. Ozawa; R. Pak; A. P. T. Palounek; V. Pantuev; V. Papavassiliou; B. H. Park; I. H. Park; J. Park; S. K. Park; W. J. Park; S. F. Pate; H. Pei; J. -C. Peng; H. Pereira; V. Peresedov; D. Yu. Peressounko; R. Petti; C. Pinkenburg; R. P. Pisani; M. Proissl; M. L. Purschke; A. K. Purwar; H. Qu; J. Rak; A. Rakotozafindrabe; I. Ravinovich; K. F. Read; S. Rembeczki; K. Reygers; V. Riabov; Y. Riabov; E. Richardson; D. Roach; G. Roche; S. D. Rolnick; M. Rosati; C. A. Rosen; S. S. E. Rosendahl; P. Rosnet; P. Rukoyatkin; P. Ruži?ka; V. L. Rykov; B. Sahlmueller; N. Saito; T. Sakaguchi; S. Sakai; K. Sakashita; V. Samsonov; S. Sano; M. Sarsour; T. Sato; M. Savastio; S. Sawada; K. Sedgwick; J. Seele; R. Seidl; A. Yu. Semenov; V. Semenov; R. Seto; D. Sharma; I. Shein; T. -A. Shibata

    2012-11-16

    The three Upsilon states, Upsilon(1S+2S+3S), are measured in d+Au and p+p collisions at sqrt(s_NN)=200 GeV and rapidities 1.2<|y|<2.2 by the PHENIX experiment at the Relativistic Heavy-Ion Collider. Cross sections for the inclusive Upsilon(1S+2S+3S) production are obtained. The inclusive yields per binary collision for d+Au collisions relative to those in p+p collisions (R_dAu) are found to be 0.62 +/- 0.26 (stat) +/- 0.13 (syst) in the gold-going direction and 0.91 +/- 0.33 (stat) +/- 0.16 (syst) in the deuteron-going direction. The measured results are compared to a nuclear-shadowing model, EPS09 [JHEP 04, 065 (2009)], combined with a final-state breakup cross section, sigma_br, and compared to lower energy p+A results. We also compare the results to the PHENIX J/psi results [Phys. Rev. Lett. 107, 142301 (2011)]. The rapidity dependence of the observed Upsilon suppression is consistent with lower energy p+A measurements.

  10. Hadronic production of J/{psi} at large {chi}{sub F} in 800 GeV p+Cu and p+Be collisions

    SciTech Connect (OSTI)

    Kowitt, M.S.

    1992-12-01

    The differential cross-section d{sigma}/dx{sub F} for J/{psi} production in 800 GeV proton-nucleus collisions has been measured in the kinematic range 0.30 {le} x{sub F} {le} 0.95 and x{sub F} {lt} p{perpendicular} {lt} 5 GeV through the decay mode J/{psi} {yields} {mu}{sup +}{mu}{sup {minus}}. The nuclear dependence of J/{psi} production over this range was measured using copper and beryllium targets. The differential cross sections are in good agreement with the predictions of the symbolical parton duality model. The data show no evidence for an intrinsic charm component in the proton. The ratio of the differential cross sections for copper and beryllium shows a suppression of J/{psi} production in copper which increases with increasing x{sub F}.

  11. Thermoelectric properties of nanoporous Ge

    E-Print Network [OSTI]

    Lee, Joo-Hyoung

    We computed thermoelectric properties of nanoporous Ge (np-Ge) with aligned pores along the [001] direction through a combined classical molecular dynamics and first-principles electronic structure approach. A significant ...

  12. GE Anna Heijbel / The Storm

    E-Print Network [OSTI]

    Tian, Weidong

    1 / GE Anna Heijbel / The Storm® Confocal Optics 50, 100, 200 µm 5 IQTL · ·DNA ·DNA Gels, blots, tissue sections (not in situ), radio-TLC & X-Ray diffraction #12;2 / GE Anna Heijbel / Phosphor µm 1010 43 x 35 cm43 x 35 cm Scanning Technology #12;3 / GE Anna Heijbel / Confocal Optics PMTPMT

  13. On The Origin of Light Dark Matter Species

    SciTech Connect (OSTI)

    Essig, Rouven; Kaplan, Jared; Schuster, Philip; /SLAC; Toro, Natalia; /Stanford U., Phys. Dept.

    2010-06-04

    TeV-mass dark matter charged under a new GeV-scale gauge force can explain electronic cosmic-ray anomalies. We propose that the CoGeNT and DAMA direct detection experiments are observing scattering of light stable states 'GeV-Matter' that are charged under this force and constitute a small fraction of the dark matter halo. Dark higgsinos in a supersymmetric dark sector are natural candidates for GeV-Matter that scatter off protons with a universal cross-section of 5 x 10{sup -38} cm{sup 2} and can naturally be split by 10-30 keV so that their dominant interaction with protons is down-scattering. As an example, down-scattering of an O(5) GeV dark higgsino can simultaneously explain the spectra observed by both CoGeNT and DAMA. The event rates in these experiments correspond to a GeV-Matter abundance of 0.2-1% of the halo mass density. This abundance can arise directly from thermal freeze-out at weak coupling, or from the late decay of an unstable TeV-scale WIMP. Our proposal can be tested by searches for exotics in the BaBar and Belle datasets.

  14. Characteristics of Sn segregation in Ge/GeSn heterostructures

    SciTech Connect (OSTI)

    Li, H.; Chang, C.; Chen, T. P.; Cheng, H. H., E-mail: hhcheng@ntu.edu.tw [Center for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Shi, Z. W.; Chen, H. [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-10-13

    We report an investigation of Sn segregation in Ge/GeSn heterostructures occurred during the growth by molecular beam epitaxy. The measured Sn profile in the Ge layer shows that: (a) the Sn concentration decreases rapidly near the Ge/GeSn interface, and (b) when moving away from the interface, the Sn concentration reduced with a much slower rate. The 1/e decay lengths of the present system are much longer than those of the conventional group IV system of Ge segregation in the Si overlayer because of the smaller kinetic potential as modeled by a self-limited two-state exchange scheme. The demonstration of the Sn segregation shows the material characteristics of the heterostructure, which are needed for the investigation of its optical properties.

  15. CTu2J.4.pdf CLEO Technical Digest OSA 2012 Selective-Area Growth of Ge and Ge/SiGe Quantum Wells

    E-Print Network [OSTI]

    Miller, David A. B.

    CTu2J.4.pdf CLEO Technical Digest © OSA 2012 Selective-Area Growth of Ge and Ge/SiGe Quantum Wells process for growing high-quality bulk Ge and Ge/SiGe quantum wells in selected areas of 3 µm thick silicon. Introduction and motivation Ge and especially Ge/SiGe quantum wells exhibit strong electroabsorption (Franz

  16. GE Partners on Microgrid Project | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    control platform which can be used to host intelligent grid management software for microgrids. A typical GE control platform which can be used to host intelligent grid management...

  17. GE Develops High Water Recovery Technology in China | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    purification industry SHANGHAI, September. 17, 2015 - A team of scientists led by the Coating and Membrane Technology Laboratory at GE's China Technology Center have successfully...

  18. Structural and phonon transmission study of Ge-Au-Ge eutectically bonded interfaces

    SciTech Connect (OSTI)

    Knowlton, W.B. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley Lab., CA (United States). Materials Sciences Div.

    1995-07-01

    This thesis presents a structural analysis and phonon transparency investigation of the Ge-Au-Ge eutectic bond interface. Interface development was intended to maximize the interfacial ballistic phonon transparency to enhance the detection of the dark matter candidate WIMPs. The process which was developed provides an interface which produces minimal stress, low amounts of impurities, and insures Ge lattice continuity through the interface. For initial Au thicknesses of greater than 1,000 {angstrom} Au per substrate side, eutectic epitaxial growth resulted in a Au dendritic structure with 95% cross sectional and 90% planar Au interfacial area coverages. In sections in which Ge bridged the interface, lattice continuity across the interface was apparent. Epitaxial solidification of the eutectic interface with initial Au thicknesses < 500 A per substrate side produced Au agglomerations thereby reducing the Au planar interfacial area coverage to as little as 30%. The mechanism for Au coalescence was attributed to lateral diffusion of Ge and Au in the liquid phase during solidification. Phonon transmission studies were performed on eutectic interfaces with initial Au thicknesses of 1,000 {angstrom}, 500 {angstrom}, and 300 {angstrom} per substrate side. Phonon imaging of eutectically bonded samples with initial Au thicknesses of 300 {angstrom}/side revealed reproducible interfacial percent phonon transmissions from 60% to 70%. Line scan phonon imaging verified the results. Phonon propagation TOF spectra distinctly showed the predominant phonon propagation mode was ballistic. This was substantiated by phonon focusing effects apparent in the phonon imaging data. The degree of interface transparency to phonons and resulting phonon propagation modes correlate with the structure of the interface following eutectic solidification. Structural studies of samples with initial Au thickness of 1,000 {angstrom}/side appear to correspond with the phonon transmission study.

  19. GE Healthcare Product Guide 2007

    E-Print Network [OSTI]

    Lebendiker, Mario

    GE Healthcare BioProcess Product Guide 2007 #12;How to contact us Europe www.gehealthcare.com/bioprocess or by phone (T), fax (F), and Email Austria T: +43 1 57 606 1613 F: +43 1 57 606 1614 Email: cust.orderde@ge.com Belgium T: 0800 73890 F: 02 416 8206 Email: order.bnl@ge.com Central and East Europe (Austria) T: +43 1

  20. Twist-3 fragmentation effects for $A_{LT}$ in light hadron production from proton-proton collisions

    E-Print Network [OSTI]

    Koike, Y; Takagi, Y; Yoshida, S

    2015-01-01

    We compute the contribution from the twist-3 fragmentation function for light hadron production in collisions between transversely and longitudinally polarized protons, i.e., $p^\\uparrow \\vec{p} \\to h\\,X$, which can cause a double-spin asymmetry (DSA) $A_{LT}$. This is a na\\"{i}ve T-even twist-3 observable that we analyze in collinear factorization using both Feynman gauge and lightcone gauge as well as give a general proof of color gauge invariance. So far only twist-3 effects in the transversely polarized proton have been studied for $A_{LT}$ in $p^\\uparrow \\vec{p} \\to h\\,X$. However, there are indications that the na\\"{i}ve T-odd transverse single-spin asymmetry (SSA) $A_N$ in $p^\\uparrow p \\to h\\,X$ is dominated not by such distribution effects but rather by a fragmentation mechanism. Therefore, one may expect similarly that the fragmentation contribution is important for $A_{LT}$. Given possible plans at RHIC to measure this observable, it is timely to provide a calculation of this term.

  1. Magnetic Refrigeration | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and it will become hotter. Move it away (demagnetization) and the food cools down. GE researchers predict the cooling refrigerators could reduce energy consumption by 20%, in...

  2. Flexible Energy | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (Opens in new window) Flexible Fuel Solutions Offer Efficient, Reliable Energy The world of power generation is evolving at lightning speed. GE is focused on staying one step...

  3. GE Energy Management Ancillary Services

    E-Print Network [OSTI]

    GE Energy Management Ancillary Services Definitions and Capability Study Part 2, Tasks 3-4, Final Online Wind Plants & Frequency Responsive Load Reserves

  4. Scalar Dark Matter From Theory Space

    SciTech Connect (OSTI)

    Birkedal-Hansen, Andreas; Wacker, Jay G.

    2003-12-26

    The scalar dark matter candidate in a prototypical theory space little Higgs model is investigated. We review all details of the model pertinent to a relic density calculation. We perform a thermal relic density calculation including couplings to the gauge and Higgs sectors of the model. We find two regions of parameter space that give acceptable dark matter abundances. The first region has a dark matter candidate with a mass {Omicron}(100 GeV), the second region has a candidate with a mass greater than {Omicron}(500 GeV). The dark matter candidate in either region is an admixture of an SU(2) triplet and an SU(2) singlet, thereby constituting a possible WIMP (weakly interacting massive particle).

  5. On the capture of dark matter by neutron stars

    SciTech Connect (OSTI)

    Güver, Tolga; Erkoca, Arif Emre; Sarcevic, Ina; Reno, Mary Hall E-mail: aeerkoca@gmail.com E-mail: ina@physics.arizona.edu

    2014-05-01

    We calculate the number of dark matter particles that a neutron star accumulates over its lifetime as it rotates around the center of a galaxy, when the dark matter particle is a self-interacting boson but does not self-annihilate. We take into account dark matter interactions with baryonic matter and the time evolution of the dark matter sphere as it collapses within the neutron star. We show that dark matter self-interactions play an important role in the rapid accumulation of dark matter in the core of the neutron star. We consider the possibility of determining an exclusion region of the parameter space for dark matter mass and dark matter interaction cross section with the nucleons as well as dark matter self-interaction cross section, based on the observation of old neutron stars. We show that for a dark matter density of 10{sup 3} GeV/cm{sup 3}and dark matter mass m{sub ?} ?< 10 GeV, there is a potential exclusion region for dark matter interactions with nucleons that is three orders of magnitude more stringent than without self-interactions. The potential exclusion region for dark matter self-interaction cross sections is many orders of magnitude stronger than the current Bullet Cluster limit. For example, for high dark matter density regions, we find that for m{sub ?} ? 10 GeV when the dark matter interaction cross section with the nucleons ranges from ?{sub ?n} ? 10{sup ?52} cm{sup 2} to ?{sub ?n} ? 10{sup ?57} cm{sup 2}, the dark matter self-interaction cross section limit is ?{sub ??} ?< 10{sup ?33} cm{sup 2}, which is about ten orders of magnitude stronger than the Bullet Cluster limit.

  6. The C-4 Dark Matter Experiment

    SciTech Connect (OSTI)

    Bonicalzi, Ricco; Collar, J. I.; Colaresi, J.; Fast, James E.; Fields, N.; Fuller, Erin S.; Hai, M.; Hossbach, Todd W.; Kos, Marek S.; Orrell, John L.; Overman, Cory T.; Reid, Douglas J.; VanDevender, Brent A.; Wiseman, Clinton G.; Yocum, K. M.

    2013-06-01

    Abstract We describe the experimental design of C-4, an expansion of the CoGeNT dark matter search to four identical detectors each approximately three times the mass of the p-type point contact (PPC) germanium diode presently taking data at the Soudan Underground Laboratory. Expected reductions of radioactive backgrounds and energy threshold are discussed, including an estimate of the additional sensitivity to low-mass dark matter candidates to be obtained with this search.

  7. Low-voltage broad-band electroabsorption from thin Ge/SiGe

    E-Print Network [OSTI]

    Miller, David A. B.

    Low-voltage broad-band electroabsorption from thin Ge/SiGe quantum wells epitaxially grown than 5 dB over the entire telecommunication S- and C-bands with only 1V drive using a new Ge/SiGe QW epitaxy design approach; further, this is demonstrated with the thinnest Ge/SiGe epitaxy to date, using

  8. CHEM 114 GE 124 MATH 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    GE 449# GE 110 Geological Engineering CE 271 GEOE 378 4TH YEAR 3RD YEAR 2ND YEAR 1ST YEAR or PHYS 128

  9. Dark Matters

    ScienceCinema (OSTI)

    Joseph Silk

    2010-01-08

    One of the greatest mysteries in the cosmos is that it is mostly dark.  Astronomers and particle physicists today are seeking to unravel the nature of this mysterious, but pervasive dark matter which has profoundly influenced the formation of structure in the universe.  I will describe the complex interplay between galaxy formation and dark matter detectability and review recent attempts to measure particle dark matter by direct and indirect means.

  10. Miniaturized Turbine Offers Desalination Solution | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    salt from ice New solution draws from the GE Store, integrating GE's experience with steam turbine, oil & gas compressors, 3D printing and water processing NISKAYUNA, NY,...

  11. Energy Frontier Research Center | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    include GE Global Research, Yale University-Crabtree Group, Yale University-Batista Group, Stanford University and Lawrence Berkeley National Laboratory. GE Global...

  12. The DAMIC dark matter experiment

    E-Print Network [OSTI]

    Aguilar-Arevalo, A; Bertou, X; Bole, D; Butner, M; Cancelo, G; Vázquez, A Castañeda; Chavarria, A E; Neto, J R T de Mello; Dixon, S; D'Olivo, J C; Estrada, J; Moroni, G Fernandez; Torres, K P Hernández; Izraelevitch, F; Kavner, A; Kilminster, B; Lawson, I; Liao, J; López, M; Molina, J; Moreno-Granados, G; Pena, J; Privitera, P; Sarkis, Y; Scarpine, V; Schwarz, T; Haro, M Sofo; Tiffenberg, J; Machado, D Torres; Trillaud, F; You, X; Zhou, J

    2015-01-01

    The DAMIC (Dark Matter in CCDs) experiment uses high resistivity, scientific grade CCDs to search for dark matter. The CCD's low electronic noise allows an unprecedently low energy threshold of a few tens of eV that make it possible to detect silicon recoils resulting from interactions of low mass WIMPs. In addition the CCD's high spatial resolution and the excellent energy response results in very effective background identification techniques. The experiment has a unique sensitivity to dark matter particles with masses below 10 GeV/c$^2$. Previous results have demonstrated the potential of this technology, motivating the construction of DAMIC100, a 100 grams silicon target detector currently being installed at SNOLAB. In this contribution, the mode of operation and unique imaging capabilities of the CCDs, and how they may be exploited to characterize and suppress backgrounds will be discussed, as well as physics results after one year of data taking.

  13. How Will Mind Overcome Matter | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy, Ph.D.Food Drive HolidayHours UsedFireAmberMind Overcome

  14. Edison Summit Brings GE Leaders Together | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    We are ONE Edison Aisha Yousuf 2014.03.21 "We are ONE Edison" was the theme of the first GE Global Edison Summit held February 16-18, 2014 at Coronado Springs Resort in Orlando,...

  15. GE Researcher Explores Science Behind Movie Chappie | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    When Will We Have Robot Best Friends? A GE Researcher Explores the Science Behind Movie Magic Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new...

  16. CHEM 114 GE 124 MATH 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    2005-2006 CHEM 114 GE 124 MATH 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 GEOL 245 MATH 223 CE 328 CE 212 CE 225 CE 295GE 213# MATH 224 GEOL 224 GEOE 218 GEOL 258 BusSci/HSS# GEOE 315 GEOE

  17. CHEM 114 GE 124 MATH 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    2006-07 CHEM 114 GE 124 MATH 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120 GEOL 245 MATH 223 CE 328 CE 212 CE 225 CE 295GE 213# MATH 224 GEOL 224 GEOE 218 GEOL 258 Hum/SocSci Jr. GEOE 315

  18. Advanced Analytics | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    GE Predictivity(tm) Industrial Internet Solutions Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window)...

  19. Evaluation of Metal Halide, Plasma, and LED Lighting Technologies for a Hydrogen Fuel Cell Mobile Light (H 2 LT)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Miller, L. B.; Donohoe, S. P.; Jones, M. H.; White, W. A.; Klebanoff, L. E.; Velinsky, S. A.

    2015-04-22

    This article reports on the testing and comparison of a prototype hydrogen fuel cell light tower (H2LT) and a conventional diesel-powered metal halide light trailer for use in road maintenance and construction activities. The prototype was originally outfitted with plasma lights and then with light-emitting diode (LED) luminaires. Light output and distribution, lighting energy efficiency (i.e., efficacy), power source thermal efficiency, and fuel costs are compared. The metal halide luminaires have 2.2 and 3.1 times more light output than the plasma and LED luminaires, respectively, but they require more power/lumen to provide that output. The LED luminaires have 1.6 timesmore »better light efficacy than either the metal halide or plasma luminaires. The light uniformity ratios produced by the plasma and LED towers are acceptable. The fuel cell thermal efficiency at the power required to operate the plasma lights is 48%, significantly higher than the diesel generator efficiency of 23% when operating the metal halide lights. Due to the increased efficiency of the fuel cell and the LED lighting, the fuel cost per lumen-hour of the H2LT is 62% of the metal halide diesel light tower assuming a kilogram of hydrogen is twice the cost of a gallon of diesel fuel.« less

  20. Recommended GE Curriculum for the BSEE Majors

    E-Print Network [OSTI]

    Ravikumar, B.

    Recommended GE Curriculum for the BSEE Majors Area Subjects Suggested GE Courses Courses Actual units GE Units A. Communication and Critical Thinking (9) A.2. Fund. of Communication ENGL 101 4 4 A.3, Theatre, Dance and Music and Film Select from the GE C.1 list in the SSU Catalog 3 3 C.2. Literature

  1. HSE 1 HSE 2 HSE 3 GE 1 GE 2 GE 3 Residual effects of Large Vessels in GE BOLD Differential Mapping of Ocular Dominance Columns

    E-Print Network [OSTI]

    HSE 1 HSE 2 HSE 3 GE 1 GE 2 GE 3 Residual effects of Large Vessels in GE BOLD Differential Mapping the contamination of non-specific large vessel signals. Animal studies have used non- conventional functional minimizing the contributions of extravascular BOLD signals around large vessels due to the refocusing pulse

  2. Dark Matter Searche with GLAST

    E-Print Network [OSTI]

    E. Nuss

    2007-04-20

    The Gamma-Ray Large Area Space Telescope (GLAST), scheduled to be launched in fall 2007, is the next generation satellite for high-energy gamma-ray astronomy. The Large Area Telescope (LAT), GLAST main instrument, with a wide field of view (> 2 sr), a large effective area (> 8000 cm^2 at 1 GeV) and 20 MeV - 300 GeV energy range, will provide excellent high energy gamma-ray observations for Dark Matter searches. In this paper we examine the potential of the LAT to detect gamma-rays coming from WIMPS annihilation in the context of supersymmetry. As an example, two search regions are investigated: the galactic center and the galactic satellites.

  3. Two-portal Dark Matter

    E-Print Network [OSTI]

    Karim Ghorbani; Hossein Ghorbani

    2015-06-14

    We propose a renormalizable dark matter model in which a fermionic dark matter (DM) candidate communicates with the standard model particles through two distinct portals: Higgs and vector portals. The dark sector is charged under a $U(1)'$ gauge symmetry while the standard model has a leptophobic interaction with the dark vector boson. The leading contribution of DM-nucleon elastic scattering cross section begins at one-loop level. The model meets all the constraints imposed by direct detection experiments provided by LUX and XENON100, observed relic abundance according to WMAP and Planck, and the invisible Higgs decay width measured at the LHC. It turns out that the dark matter mass in the viable parameter space can take values from a few GeV up to 1 TeV. This is a new feature which is absent in the models with only one portal. In addition, we can find in the constrained regions of the parameter space a DM mass of $\\sim 34$ GeV annihilating into $b$ quark pair, which explains the Fermi-LAT gamma-ray excess.

  4. Strained Si, SiGe, and Ge on-insulator: review of wafer bonding fabrication techniques

    E-Print Network [OSTI]

    Strained Si, SiGe, and Ge on-insulator: review of wafer bonding fabrication techniques Gianni was arranged by Prof. C.K. Maiti Abstract Techniques for fabricating strained Si, SiGe, and Ge on-insulator include SIMOX, Ge condensation and wafer bonding. In this paper, a brief introduction of each method

  5. GeSi intermixing in Ge quantum dots on Si,,001... and Si,,111... F. Boscherinia)

    E-Print Network [OSTI]

    Ge­Si intermixing in Ge quantum dots on Si,,001... and Si,,111... F. Boscherinia) Laboratori December 1999 Exploiting Ge K-edge x-ray absorption spectroscopy we provide direct evidence of Si­Ge intermixing in self-organized strained and unstrained Ge quantum dots on Si, and provide a quantitative

  6. Nonlithographic epitaxial SnxGe1x dense nanowire arrays grown on Ge,,001...

    E-Print Network [OSTI]

    Atwater, Harry

    Nonlithographic epitaxial SnxGe1Àx dense nanowire arrays grown on Ge,,001... Regina Ragan-thick SnxGe1 x /Ge(001) epitaxial films with 0 x 0.085 by molecular-beam epitaxy. These films evolve during growth into a dense array of SnxGe1 x nanowires oriented along 001 , as confirmed by composition contrast

  7. 7-GeV Advanced Photon Source Conceptual Design Report

    SciTech Connect (OSTI)

    Not Available

    1987-04-01

    During the past decade, synchrotron radiation emitted by circulating electron beams has come into wide use as a powerful, versatile source of x-rays for probing the structure of matter and for studying various physical processes. Several synchrotron radiation facilities with different designs and characteristics are now in regular operation throughout the world, with recent additions in this country being the 0.8-GeV and 2.5-GeV rings of NSLS at Brookhaven National Laboratory. However, none of the operating facilities has been designed to use a low-emittance, high-energy stored beam, together with modern undulator devices, to produce a large number of hard x-ray beams of extremely high brilliance. This document is a proposal to the Department of Energy to construct and operate high-energy synchrotron radiation facility at Argonne National Laboratory. We have now chosen to set the design energy of this facility at 7.0 GeV, with the capability to operate at up to 7.5 GeV.

  8. Exclusive pi^0 electroproduction at W > 2 GeV with CLAS

    SciTech Connect (OSTI)

    Bedlinskiy, I.; Kubarovsky, V.; Niccolai, S.; Stoler, P.; Adhikari, K.P.; Anderson, M.D.; Pereira, S. Anefalos; Avakian, H.; Ball, J.; Baltzell, N.A.; Battaglieri, M.; Batourine, V.; Biselli, A.S.; Boiarinov, S.; Bono, J.; Briscoe, W.J.; Brooks, W.K.; Burkert, V.D.; Carman, D.S.; Celentano, A.; Chandavar, S.; Colaneri, L.; Cole, P.L.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Doughty, D.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fleming, J.A.; Forest, T.A.; Garillon, B.; Garcon, M.; Gavalian, G.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G.P.; Giovanetti, K.L.; Girod, F.X.; Golovatch, E.; Gothe, R.W.; Griffioen, K.A.; Guegan, B.; Guo, L.; Hafidi, K.; Hakobyan, H.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Ireland, D.G.; Ishkhanov, B.S.; Isupov, E.L.; Jenkins, D.; Jo, H.S.; Joo, K.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F.J.; Koirala, S.; Kuhn, S.E.; Kuleshov, S.V.; Lenisa, P.; Levine, W.I.; Livingston, K.; Lu, H.Y.; MacGregor, I.J.D.; Markov, N.; Mayer, M.; McKinnon, B.; Mirazita, M.; Mokeev, V.; Montgomery, R.A.; Moody, C.I.; Moutarde, H.; Movsisyan, A; Munoz Camacho, C.; Nadel-Turonski, P.; Niculescu, I.; Osipenko, M.; Ostrovidov, A.I.; Pappalardo, L.L.; Park, K.; Park, S.; Pasyuk, E.; Phelps, E.; Phelps, W.; Phillips, J.J.; Pisano, S.; Pogorelko, O.; Price, J.W.; Prok, Y.; Protopopescu, D.; Procureur, S.; Puckett, A.J.R.; Raue, B.A.; Ripani, M.; Ritchie, B.G.; Rizzo, A.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R.A.; Seder, E.; Senderovich, I.; Sharabian, Y.G.; Simonyan, A.; Smith, G.D.; Sober, D.I.; Sokhan, D.; Stepanyan, S.S.; Strauch, S.; Sytnik, V.; Tang, W.; Tian, Ye; Ungaro, M.; Vlassov, A.V.; Voskanyan, H.; Voutier, E.; Walford, N.K.; Watts, D.; Wei, X.; Weinstein, L.B.; Yurov, M.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z.W.; Zonta, I.

    2014-08-01

    Exclusive neutral-pion electroproduction (ep-->e'p'pi0) was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections d4sigma/dtdQ2dxBdphipi and structure functions sigmaT+epsilonsigmaL,sigmaTT and ?LT as functions of t were obtained over a wide range of Q2 and xB. The data are compared with Regge and handbag theoretical calculations. Analyses in both frameworks find that a large dominance of transverse processes is necessary to explain the experimental results. For the Regge analysis it is found that the inclusion of vector meson rescattering processes is necessary to bring the magnitude of the calculated and measured structure functions into rough agreement. In the handbag framework, there are two independent calculations, both of which appear to roughly explain the magnitude of the structure functions in terms of transversity generalized parton distributions.

  9. Contamination of Dark Matter Experiments from Atmospheric Magnetic Dipoles

    E-Print Network [OSTI]

    A. Bueno; M. Masip; P. Sánchez-Lucas; N. Setzer

    2013-10-14

    Dark matter collisions with heavy nuclei (Xe, Ge, Si, Na) may produce recoils observable at direct-search experiments. Given that some of these experiments are yielding conflicting information, however, it is worth asking if physics other than dark matter may produce similar nuclear recoils. We examine under what conditions an atmospherically-produced neutral particle with a relatively large magnetic dipole moment could fake a dark matter signal. We argue that a very definite flux could explain the signals seen at DAMA/LIBRA, CDMS/Si and CoGeNT consistently with the bounds from XENON100 and CDMS/Ge. To explore the plausibility of this scenario, we discuss a concrete model with 10-50 MeV sterile neutrinos that was recently proposed to explain the LSND and MiniBooNE anomalies.

  10. Double-Disk Dark Matter

    E-Print Network [OSTI]

    JiJi Fan; Andrey Katz; Lisa Randall; Matthew Reece

    2013-07-31

    Based on observational constraints on large scale structure and halo structure, dark matter is generally taken to be cold and essentially collisionless. On the other hand, given the large number of particles and forces in the visible world, a more complex dark sector could be a reasonable or even likely possibility. This hypothesis leads to testable consequences, perhaps portending the discovery of a rich hidden world neighboring our own. We consider a scenario that readily satisfies current bounds that we call Partially Interacting Dark Matter (PIDM). This scenario contains self-interacting dark matter, but it is not the dominant component. Even if PIDM contains only a fraction of the net dark matter density, comparable to the baryonic fraction, the subdominant component's interactions can lead to interesting and potentially observable consequences. Our primary focus will be the special case of Double-Disk Dark Matter (DDDM), in which self-interactions allow the dark matter to lose enough energy to lead to dynamics similar to those in the baryonic sector. We explore a simple model in which DDDM can cool efficiently and form a disk within galaxies, and we evaluate some of the possible observational signatures. The most prominent signal of such a scenario could be an enhanced indirect detection signature with a distinctive spatial distribution. Even though subdominant, the enhanced density at the center of the galaxy and possibly throughout the plane of the galaxy can lead to large boost factors, and could even explain a signature as large as the 130 GeV Fermi line. Such scenarios also predict additional dark radiation degrees of freedom that could soon be detectable and would influence the interpretation of future data, such as that from Planck and from the Gaia satellite. We consider this to be the first step toward exploring a rich array of new possibilities for dark matter dynamics.

  11. Constraints on Light Dark Matter from Big Bang Nucleosynthesis

    E-Print Network [OSTI]

    Brian Henning; Hitoshi Murayama

    2012-05-29

    We examine the effects of relic dark matter annihilations on big bang nucleosynthesis (BBN). The magnitude of these effects have scale simply with the dark matter mass and annihilation cross-section, which we derive. Estimates based on these scaling behaviors indicate that BBN severely constrains hadronic and radiative dark matter annihilation channels in the previously unconsidered dark matter mass region MeV $\\lesssim m_{\\chi} \\lesssim 10$ GeV. Interestingly, we find that BBN constraints on hadronic annihilation channels are competitive with similar bounds derived from the cosmic microwave background.

  12. CHEM 114 GE 124 MATH 110 GE 110 COMM 102 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    ND YEAR 1ST YEAR 3RD YEAR # These courses can be taken in either term.*must meet specific Hum/SocSci@# Bus Sci/HSS#Design Elec.#* T.E.*# T.E.*#GE 449# ME 314 or PHYS 128 or GEOL 121 4TH YEAR 2

  13. GE Energy Management Ancillary Services

    E-Print Network [OSTI]

    GE Energy Management Ancillary Services Definitions and Capability Study Part 1, Tasks 1-2, FinalRose Michael O'Connor Sundar Venkataraman Revision 1 Date: 12/19/2012 #12;Ancillary Services Definitions.................................................................................................................... 7 3.1 Task 1: Identify and define ancillary services needed for integration of new generation

  14. Microgravity and Vision in Astronauts | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on dark matterEnergyPublicatonsSubstancesproteinGE Researchers Study

  15. Constraints on particle dark matter from cosmic-ray antiprotons

    E-Print Network [OSTI]

    N. Fornengo; L. Maccione; A. Vittino

    2015-01-30

    Cosmic-ray antiprotons represent an important channel for dark matter indirect-detection studies. Current measurements of the antiproton flux at the top of the atmosphere and theoretical determinations of the secondary antiproton production in the Galaxy are in good agreement, with no manifest deviation which could point to an exotic contribution in this channel. Therefore, antiprotons can be used as a powerful tool for constraining particle dark matter properties. By using the spectrum of PAMELA data from 50 MV to 180 GV in rigidity, we derive bounds on the dark matter annihilation cross section (or decay rate, for decaying dark matter) for the whole spectrum of dark matter annihilation (decay) channels and under different hypotheses of cosmic-rays transport in the Galaxy and in the heliosphere. For typical models of galactic propagation, the constraints are significantly strong, setting a lower bound on the dark matter mass of a "thermal" relic at about 50-90 GeV for hadronic annihilation channels. These bounds are enhanced to about 150 GeV on the dark matter mass, when large cosmic-rays confinement volumes in the Galaxy are considered, and are reduced to 4-5 GeV for annihilation to light quarks (no bound for heavy-quark production) when the confinement volume is small. Bounds for dark matter lighter than few tens of GeV are due to the low energy part of the PAMELA spectrum, an energy region where solar modulation is relevant: to this aim, we have implemented a detailed solution of the transport equation in the heliosphere, which allowed us not only to extend bounds to light dark matter, but also to determine the uncertainty on the constraints arising from solar modulation modeling. Finally, we estimate the impact of soon-to-come AMS-02 data on the antiproton constraints.

  16. Indirect dark matter search with AMS-02

    E-Print Network [OSTI]

    S. Di Falco

    2006-07-06

    The Alpha Magnetic Spectrometer (AMS), to be installed on the International Space Station, will provide data on cosmic radiations in the energy range from 0.5 GeV to 3 TeV. The main physics goals are the anti-matter and the dark matter searches. Observations and cosmology indicate that the Universe may include a large amount of unknown Dark Matter. It should be composed of non baryonic Weakly Interacting Massive Particles (WIMP). In R-parity conserving models a good WIMP candidate is the lightest SUSY particle. AMS offers a unique opportunity to study simultaneously SUSY dark matter in three decay channels resulting from the neutralino annihilation: e+, antiproton and gamma. Either in the SUSY frame and in alternative scenarios (like extra-dimensions) the expected flux sensitivities as a function of energy in 3 year exposure for the e+/e- ratio, gamma and antiproton yields are presented.

  17. Scalar Dark Matter: Direct vs. Indirect Detection

    E-Print Network [OSTI]

    Michael Duerr; Pavel Fileviez Perez; Juri Smirnov

    2015-09-14

    We revisit the simplest model for dark matter. In this context the dark matter candidate is a real scalar field which interacts with the Standard Model particles through the Higgs portal. We discuss the relic density constraints as well as the predictions for direct and indirect detection. The final state radiation processes are investigated in order to understand the visibility of the gamma lines from dark matter annihilation. We find two regions where one could observe the gamma lines at gamma-ray telescopes. We point out that the region where the dark matter mass is between 100 and 300 GeV can be tested in the near future at direct and indirect detection experiments.

  18. Scalar Dark Matter: Direct vs. Indirect Detection

    E-Print Network [OSTI]

    Duerr, Michael; Smirnov, Juri

    2015-01-01

    We revisit the simplest model for dark matter. In this context the dark matter candidate is a real scalar field which interacts with the Standard Model particles through the Higgs portal. We discuss the relic density constraints as well as the predictions for direct and indirect detection. The final state radiation processes are investigated in order to understand the visibility of the gamma lines from dark matter annihilation. We find two regions where one could observe the gamma lines at gamma-ray telescopes. We point out that the region where the dark matter mass is between 100 and 300 GeV can be tested in the near future at direct and indirect detection experiments.

  19. Anticipating Patentable Subject Matter

    E-Print Network [OSTI]

    Burk, DL

    2015-01-01

    February 2013] PATENTABLE SUBJECT MATTER patentability—imports into patent law’s subject matter provisions theunder either novelty or subject matter. The proper question

  20. 3.8 F I S H H E A LT H A S S E S S M E N T by Beverley Raymond, D. Patrick Shaw

    E-Print Network [OSTI]

    chlorophenolics, dioxins and furans from pulp mills resulted in research on effects of contaminants on juvenile E A LT H A S S E S S M E N T province-wide dioxin survey which included sites on the Fraser; Tuominen and Sekela 1992; Servizi et al. 1993). Dioxin and furan surveys were repeated by the pulp mills

  1. Dark Matter Signals In Cosmic Rays?

    E-Print Network [OSTI]

    Shlomo Dado; Arnon Dar

    2009-03-10

    The flux of the diffuse gamma-ray background radiation (GBR) does not confirm that the excess in the flux of cosmic ray electrons between 300-800 GeV, which was measured locally with the ATIC instrument in balloon flights over Antartica, is universal as expected from dark matter annihilation. Neither does the increase with energy of the fraction of positrons in the cosmic ray flux of electrons in the 10-100 GeV range that was measured by PAMELA imply a dark matter origin: It is consistent with that expected from the sum of the two major sources of Galactic cosmic rays, non relativistic spherical ejecta and highly relativistic jets from supernova explosions.

  2. Axions as hot and cold dark matter

    SciTech Connect (OSTI)

    Jeong, Kwang Sik; Kawasaki, Masahiro; Takahashi, Fuminobu E-mail: kawasaki@icrr.u-tokyo.ac.jp

    2014-02-01

    The presence of a hot dark matter component has been hinted at 3? by a combination of the results from different cosmological observations. We examine a possibility that pseudo Nambu-Goldstone bosons account for both hot and cold dark matter components. We show that the QCD axions can do the job for the axion decay constant f{sub a}?GeV, if they are produced by the saxion decay and the domain wall annihilation. We also investigate the cases of thermal QCD axions, pseudo Nambu-Goldstone bosons coupled to the standard model sector through the Higgs portal, and axions produced by modulus decay.

  3. Asymmetric dark matter and the Sun

    E-Print Network [OSTI]

    Mads T. Frandsen; Subir Sarkar

    2010-06-01

    Cold dark matter particles with an intrinsic matter-antimatter asymmetry do not annihilate after gravitational capture by the Sun and can affect its interior structure. The rate of capture is exponentially enhanced when such particles have self-interactions of the right order to explain structure formation on galactic scales. A `dark baryon' of mass 5 GeV is a natural candidate and has the required relic abundance if its asymmetry is similar to that of ordinary baryons. We show that such particles can solve the `solar composition problem'. The predicted small decrease in the low energy neutrino fluxes may be measurable by the Borexino and SNO+ experiments.

  4. Matter Field, Dark Matter and Dark Energy

    E-Print Network [OSTI]

    Masayasu Tsuge

    2009-03-24

    A model concerning particle theory and cosmology is proposed. Matter field, dark matter and dark energy are created by an energy flow from space to primordial matter fields at the phase transition in the early universe.

  5. PROBABILITY OF CORRECT SELECTION OF GAMMA VERSUS GE OR WEIBULL VERSUS GE BASED ON

    E-Print Network [OSTI]

    Kundu, Debasis

    PROBABILITY OF CORRECT SELECTION OF GAMMA VERSUS GE OR WEIBULL VERSUS GE BASED ON LIKELIHOOD RATIO proposes the use of likelihood ratio statistic in choosing between gamma and GE models or between Weibull and GE models. Probability of correct selec- tions are obtained using Monte Carlo simulations for various

  6. Modulation Effects in Dark Matter-Electron Scattering Experiments

    E-Print Network [OSTI]

    Lee, Samuel K; Mishra-Sharma, Siddharth; Safdi, Benjamin R

    2015-01-01

    One of the next frontiers in dark-matter direct-detection experiments is to explore the MeV to GeV mass regime. Such light dark matter does not carry enough kinetic energy to produce an observable nuclear recoil, but it can scatter off electrons, leading to a measurable signal. We introduce a semi-analytic approach to characterize the resulting electron-scattering events in atomic and semiconductor targets, improving on previous analytic proposals that underestimate the signal at high recoil energies. We then use this procedure to study the time-dependent properties of the electron-scattering signal, including the modulation fraction, higher-harmonic modes and modulation phase. The time dependence can be distinct in a non-trivial way from the nuclear scattering case. Additionally, we show that dark-matter interactions inside the Earth can significantly distort the lab-frame phase-space distribution of sub-GeV dark matter.

  7. Discovering Inelastic Thermal-Relic Dark Matter at Colliders

    E-Print Network [OSTI]

    Izaguirre, Eder; Shuve, Brian

    2015-01-01

    Dark Matter particles with inelastic interactions are ubiquitous in extensions of the Standard Model, yet remain challenging to fully probe with existing strategies. We propose a series of powerful searches at hadron and lepton colliders that are sensitive to inelastic dark matter dynamics. In representative models, we find that the LHC and BaBar could offer strong sensitivity to the thermal-relic dark matter parameter space for dark matter masses between ~100 MeV-100 GeV and fractional mass-splittings above the percent level; future searches at Belle II with a dedicated monophoton trigger could also offer sensitivity to thermal-relic scenarios with masses below a few GeV. Thermal scenarios with either larger masses or splittings are largely ruled out; lower masses remain viable yet may be accessible with other search strategies.

  8. Understanding and engineering of NiGe/Ge junction formed by phosphorus ion implantation after germanidation

    SciTech Connect (OSTI)

    Oka, Hiroshi, E-mail: oka@asf.mls.eng.osaka-u.ac.jp; Minoura, Yuya; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji [Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2014-08-11

    Modulation of the effective electron Schottky barrier height (eSBH) of NiGe/Ge contacts induced by phosphorus ion implantation after germanide formation was investigated by considering local inhomogeneity in the eSBH. Systematic studies of NiGe/Ge contact devices having various germanide thicknesses and ion implantation areas indicated the threshold dopant concentration at the NiGe/Ge interface required for eSBH modulation and negligible dopant diffusion even at NiGe/Ge interface during drive-in annealing, leading to variation in the eSBH between the bottom and sidewall portions of the NiGe regions. Consequently, this method makes it possible to design source/drain contacts with low-resistivity Ohmic and ideal rectifying characteristics for future Ge-based transistors.

  9. Direct Search for Low Mass Dark Matter Particles with CCDs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Barreto, J.; Cease, H.; Diehl, H. T.; Estrada, J.; Flaugher, B.; Harrison, N.; Jones, J.; Kilminster, B.; Molina, J.; Smith, J.; et al

    2012-05-15

    A direct dark matter search is performed using fully-depleted high-resistivity CCD detectors. Due to their low electronic readout noise (RMS ~7 eV) these devices operate with a very low detection threshold of 40 eV, making the search for dark matter particles with low masses (~5 GeV) possible. The results of an engineering run performed in a shallow underground site are presented, demonstrating the potential of this technology in the low mass region.

  10. CHEM 114 GE 124 MATH 110 COMM 102GE 110 CHEM 115# GE 125 MATH 124 PHYS 155 GE 120

    E-Print Network [OSTI]

    Saskatchewan, University of

    Engineering * must meet specific requirements # These courses can be taken in either term. 2ND YEAR 3RD YEAR 4 431 Last editted Apr 4, 2006 ^offered in alternate years; take in either 3rd or 4th year CHEM 242TH YEAR 1ST YEAR CHE 422 CHE 232 HSS@# 2005-2006 or PHYS 128 or GEOL 121 or AB E 312 GE 300# CHE 332

  11. Dark Matter with Topological Defects in the Inert Doublet Model

    E-Print Network [OSTI]

    Mark Hindmarsh; Russell Kirk; Jose Miguel No; Stephen M. West

    2015-07-29

    We examine the production of dark matter by decaying topological defects in the high mass region $m_{\\mathrm{DM}} \\gg m_W$ of the Inert Doublet Model, extended with an extra U(1) gauge symmetry. The density of dark matter states (the neutral Higgs states of the inert doublet) is determined by the interplay of the freeze-out mechanism and the additional production of dark matter states from the decays of topological defects, in this case cosmic strings. These decays increase the predicted relic abundance compared to the standard freeze-out only case, and as a consequence the viable parameter space of the Inert Doublet Model can be widened substantially. In particular, for a given dark matter annihilation rate lower dark matter masses become viable. We investigate the allowed mass range taking into account constraints on the energy injection rate from the diffuse $\\gamma$-ray background and Big Bang Nucleosynthesis, together with constraints on the dark matter properties coming from direct and indirect detection limits. For the Inert Doublet Model high-mass region, an inert Higgs mass as low as $\\sim 200$ GeV is permitted. There is also an upper limit on string mass per unit length, and hence the symmetry breaking scale, from the relic abundance in this scenario. Depending on assumptions made about the string decays, the limits are in the range $10^{12}$ GeV to $10^{13}$ GeV.

  12. ME 227 CE 212 MATH 223 GE 210 CMPT 116 ABE 211CHE 210 GE 213# MATH 224

    E-Print Network [OSTI]

    Saskatchewan, University of

    GE 120 ME 227 CE 212 MATH 223 GE 210 CMPT 116 ABE 211CHE 210 GE 213# MATH 224 ABE 295 ABE 212 can be taken in either term. GE 124 MATH 110 MATH 124CHEM 115 PHYS 155 3RD YEAR GE 125 GE 110 COMM 102

  13. Purdue, GE Collaborate On Advanced Manufacturing | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeedingProgramExemptionsProteinTotal natural gasPurchase, Delivery,Purdue, GE to

  14. About GE Global Research Center | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of raregovAboutRecovery Act Recovery ActARM OverviewAbout GE Global Research

  15. GE Scientists Experiment With Texas BBQ | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journal Article)Forthcoming UpgradesArea:Benefits ofofStackOn thePower ofGE

  16. Photoconductivity of Si/Ge multilayer structures with Ge quantum dots pseudomorphic to the Si matrix

    SciTech Connect (OSTI)

    Talochkin, A. B., E-mail: tal@thermo.isp.nsc.ru; Chistokhin, I. B. [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

    2011-07-15

    Longitudinal photoconductivity spectra of Si/Ge multilayer structures with Ge quantum dots grown pseudomorphically to the Si matrix are studied. Lines of optical transitions between hole levels of quantum dots and Si electronic states are observed. This allowed us to construct a detailed energy-level diagram of electron-hole levels of the structure. It is shown that hole levels of pseudomorphic Ge quantum dots are well described by the simplest 'quantum box' model using actual sizes of Ge islands. The possibility of controlling the position of the long-wavelength photosensitivity edge by varying the growth parameters of Si/Ge structures with Ge quantum dots is determined.

  17. Chevron, GE form Technology Alliance

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D BGene NetworkNuclear SecurityChattanChemistry ofNanChevron, GE form

  18. Advanced Analytics | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News Publications Traditional Knowledge KiosksAboutHelp & Reference Users AdvAncedGE

  19. L.T. Blackford

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    942k gallons (CY 14M) Received Environmental Restoration Disposal Facility (ERDF) leachate (119k gallons) at Liquid Effluent Retention Facility (LERF) Basin 44 (CY 1.8M)...

  20. Tesis LT.PDF

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-EnhancingEt Al., 2013) | Opensource HistoryTerraWatt PowerTerryDETERMINACION DE LA

  1. C. Lt. Cooper

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and Myers Co -VANaval ,, *' ; . FinalLI CI - -

  2. G?)~~&lt;+!T

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and700, 1.Reports1E~ S·D3 2,000 4,000DOEK I

  3. &lt;Title>

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-InspiredAtmosphericdevicesPPONeApril351APPLICATION OFsaferHe

  4. CANDLEW&lt;IDD.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAudits &Bradbury Science Museum6 Shares Craig Stevens is the CAMDMay

  5. GE Global Research in San Ramon, California

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Careers Leadership Programs What's new in San Ramon Ars Technica: Analyzing the Internet of Things GE Unveils High-Speed Network Infrastructure to Connect Machines, Data...

  6. Matter Wave Radiation Leading to Matter Teleportation

    E-Print Network [OSTI]

    Yong-Yi Huang

    2015-02-12

    The concept of matter wave radiation is put forward, and its equation is established for the first time. The formalism solution shows that the probability density is a function of displacement and time. A free particle and a two-level system are reinvestigated considering the effect of matter wave radiation. Three feasible experimental designs, especially a modified Stern-Gerlach setup, are proposed to verify the existence of matter wave radiation. Matter wave radiation effect in relativity has been formulated in only a raw formulae, which offers another explanation of Lamb shift. A possible mechanics of matter teleportation is predicted due to the effect of matter wave radiation.

  7. MOSFET Channel Engineering using Strained Si, SiGe, and Ge Channels

    E-Print Network [OSTI]

    Fitzgerald, Eugene A.

    Biaxial tensile strained Si grown on SiGe virtual substrates will be incorporated into future generations of CMOS technology due to the lack of performance increase with scaling. Compressively strained Ge-rich alloys with ...

  8. ? meson production in d+Au collisions at ?sNN = 200 GeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Adare, A.

    2015-10-19

    The PHENIX Collaboration has measured ? meson production in d+Au collisions at ?sNN=200 GeV using the dimuon and dielectron decay channels. The ? meson is measured in the forward (backward) d-going (Au-going) direction, 1.2 T) range from 1–7 GeV/c and at midrapidity |y|T range below 7 GeV/c. The ? meson invariant yields and nuclear-modification factors as a function of pT, rapidity, and centrality are reported. An enhancement of ? meson production is observed in the Au-going direction, while suppression is seen in the d-going direction,more »and no modification is observed at midrapidity relative to the yield in p+p collisions scaled by the number of binary collisions. As a result, similar behavior was previously observed for inclusive charged hadrons and open heavy flavor, indicating similar cold-nuclear-matter effects.« less

  9. Properties of galactic dark matter: Constraints from astronomical observations

    SciTech Connect (OSTI)

    Burch, B.; Cowsik, R.

    2013-12-10

    The distributions of normal matter and of dark matter in the Galaxy are coupled to each other as they both move in the common gravitational potential. In order to fully exploit this interplay and to derive the various properties of dark matter relevant to their direct and indirect detection, we have comprehensively reviewed the astronomical observations of the spatial and velocity distributions of the components of normal matter. We then postulate that the phase-space distribution of dark matter follows a lowered-isothermal form and self-consistently solve Poisson's equation to construct several models for the spatial and velocity distributions of dark matter. In this paper, we compute the total gravitational potential of the normal and dark matter components and investigate their consistency with current observations of the rotation curve of the Galaxy and of the spatial and velocity distributions of blue horizontal-branch and blue straggler stars. Even with this demand of consistency, a large number of models with a range of parameters characterizing the dark matter distribution remain. We find that the best choice of parameters, within the range of allowed values for the surface density of the disk 55 M {sub ?} pc{sup –2}, are the following: the dark matter density at the Galactic center ?{sub DM,} {sub c} ? 100-250 GeV cm{sup –3}, the local dark matter density ?{sub DM}(R {sub 0}) ? 0.56-0.72 GeV cm{sup –3}, and the rms speed of dark matter particles ?v{sub DM}{sup 2}(R{sub 0})?{sup 1/2}?490??550 km s{sup –1}. We also discuss possible astronomical observations that may further limit the range of the allowed models. The predictions of the allowed models for direct and indirect detection will be discussed separately in a companion paper.

  10. Excluding the light dark matter window of a 331 model using LHC and direct dark matter detection data

    SciTech Connect (OSTI)

    Cogollo, D.; Gonzalez-Morales, Alma X.; Queiroz, Farinaldo S.; Teles, P. Rebello E-mail: alxogonz@ucsc.edu E-mail: patricia.rebello.teles@cern.ch

    2014-11-01

    We sift the impact of the recent Higgs precise measurements, and recent dark matter direct detection results, on the dark sector of an electroweak extension of the Standard Model that has a complex scalar as dark matter. We find that in this model the Higgs decays with a large branching ratio into dark matter particles, and charged scalars when these are kinematically available, for any coupling strength differently from the so called Higgs portal. Moreover, we compute the abundance and spin-independent WIMP-nucleon scattering cross section, which are driven by the Higgs and Z{sup '} boson processes. We decisively exclude the 1–500 GeV dark matter window and find the most stringent lower bound in the literature on the scale of symmetry breaking of the model namely 10 TeV, after applying the LUX-2013 limit. Interestingly, the projected XENON1T constraint will be able to rule out the entire 1 GeV–1000 GeV dark matter mass range. Lastly, for completeness, we compute the charged scalar production cross section at the LHC and comment on the possibility of detection at current and future LHC runnings.

  11. Baryonic matter and beyond

    E-Print Network [OSTI]

    Kenji Fukushima

    2014-10-01

    We summarize recent developments in identifying the ground state of dense baryonic matter and beyond. The topics include deconfinement from baryonic matter to quark matter, a diquark mixture, topological effect coupled with chirality and density, and inhomogeneous chiral condensates.

  12. LIGHT PHOTINOS AS DARK MATTER

    E-Print Network [OSTI]

    Glennys R. Farrar; Edward W. Kolb

    1995-04-24

    There are good reasons to consider models of low-energy supersymmetry with very light photinos and gluinos. In a wide class of models the lightest $R$-odd, color-singlet state containing a gluino, the $\\r0$, has a mass in the 1-2 GeV range and the slightly lighter photino, $\\pho$, would survive as the relic $R$-odd species. For the light photino masses considered here, previous calculations resulted in an unacceptable photino relic abundance. But we point out that processes other than photino self-annihilation determine the relic abundance when the photino and $R^0$ are close in mass. Including $\\r0\\longleftrightarrow\\pho$ processes, we find that the photino relic abundance is most sensitive to the $\\r0$-to-$\\pho$ mass ratio, and within model uncertainties, a critical density in photinos may be obtained for an $\\r0$-to-$\\pho$ mass ratio in the range 1.2 to 2.2. We propose photinos in the mass range of 500 MeV to 1.6 GeV as a dark matter candidate, and discuss a strategy to test the hypothesis.

  13. Lepton-flavored dark matter

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kile, Jennifer; Kobach, Andrew; Soni, Amarjit

    2015-05-01

    In this work, we address two paradoxes. The first is that the measured dark-matter relic density can be satisfied with new physics at O(100 GeV–1 TeV), while the null results from direct-detection experiments place lower bounds of O(10 TeV) on a new-physics scale. The second puzzle is that the severe suppression of lepton-flavor-violating processes involving electrons, e.g. ? ? 3e, ? ? e??, etc., implies that generic new-physics contributions to lepton interactions cannot exist below O(10–100 TeV), whereas the 3.6? deviation of the muon g – 2 from the standard model can be explained by a new physics scale more »TeV). Here, we suggest that it may not be a coincidence that both the muon g – 2 and the relic density can be satisfied by a new-physics scale ?1 TeV. We consider the possibility of a gauged lepton-flavor interaction that couples at tree level only to ?- and ?-flavored leptons and the dark sector. Dark matter thus interacts appreciably only with particles of ? and ? flavor at tree level and has loop-suppressed couplings to quarks and electrons. Remarkably, if such a gauged flavor interaction exists at a scale O(100 GeV–1 TeV), it allows for a consistent phenomenological framework, compatible with the muon g – 2, the relic density, direct detection, indirect detection, charged-lepton decays, neutrino trident production, and results from hadron and e?e? colliders. We suggest experimental tests for these ideas at colliders and for low-energy observables. (author)« less

  14. Lepton-flavored dark matter

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kile, Jennifer; Kobach, Andrew; Soni, Amarjit

    2015-05-01

    In this work, we address two paradoxes. The first is that the measured dark-matter relic density can be satisfied with new physics at O(100 GeV–1 TeV), while the null results from direct-detection experiments place lower bounds of O(10 TeV) on a new-physics scale. The second puzzle is that the severe suppression of lepton-flavor-violating processes involving electrons, e.g. ? ? 3e, ? ? e??, etc., implies that generic new-physics contributions to lepton interactions cannot exist below O(10–100 TeV), whereas the 3.6? deviation of the muon g – 2 from the standard model can be explained by a new physics scale matter thus interacts appreciably only with particles of ? and ? flavor at tree level and has loop-suppressed couplings to quarks and electrons. Remarkably, if such a gauged flavor interaction exists at a scale O(100 GeV–1 TeV), it allows for a consistent phenomenological framework, compatible with the muon g – 2, the relic density, direct detection, indirect detection, charged-lepton decays, neutrino trident production, and results from hadron and e?e? colliders. We suggest experimental tests for these ideas at colliders and for low-energy observables. (author)

  15. Modeling of GE Appliances: Final Presentation

    SciTech Connect (OSTI)

    Fuller, Jason C.; Vyakaranam, Bharat; Leistritz, Sean M.; Parker, Graham B.

    2013-01-31

    This report is the final in a series of three reports funded by U.S. Department of Energy Office of Electricity Delivery and Energy Reliability (DOE-OE) in collaboration with GE Appliances’ through a Cooperative Research and Development Agreement (CRADA) to describe the potential of GE Appliances’ DR-enabled appliances to provide benefits to the utility grid.

  16. GE Turbine Parts www.edisonmachine.com

    E-Print Network [OSTI]

    Chiao, Jung-Chih

    GE Turbine Parts www.edisonmachine.com New authentic GE and Westinghouse Turbine Parts Muscle cars vehicle: Has the code for a hydrogen car been cracked? World-first working eukaryotic cell mad from's smallest windmills to power cell phones 1/17/2014http://www.gizmag.com/worlds-smallest-windmill-energy

  17. Dark Matter Antibaryons from a Supersymmetric Hidden Sector

    E-Print Network [OSTI]

    Nikita Blinov; David E. Morrissey; Kris Sigurdson; Sean Tulin

    2012-12-03

    The cosmological origin of both dark and baryonic matter can be explained through a unified mechanism called hylogenesis where baryon and antibaryon number are divided between the visible sector and a GeV-scale hidden sector, while the Universe remains net baryon symmetric. The "missing" antibaryons, in the form of exotic hidden states, are the dark matter. We study model-building, cosmological, and phenomenological aspects of this scenario within the framework of supersymmetry, which naturally stabilizes the light hidden sector and electroweak mass scales. Inelastic dark matter scattering on visible matter destroys nucleons, and nucleon decay searches offer a novel avenue for the direct detection of the hidden antibaryonic dark matter sea.

  18. Dark Matter Antibaryons from a Supersymmetric Hidden Sector

    E-Print Network [OSTI]

    Blinov, Nikita; Sigurdson, Kris; Tulin, Sean

    2012-01-01

    The cosmological origin of both dark and baryonic matter can be explained through a unified mechanism called hylogenesis where baryon and antibaryon number are divided between the visible sector and a GeV-scale hidden sector, while the Universe remains net baryon symmetric. The "missing" antibaryons, in the form of exotic hidden states, are the dark matter. We study model-building, cosmological, and phenomenological aspects of this scenario within the framework of supersymmetry, which naturally stabilizes the light hidden sector and electroweak mass scales. Inelastic dark matter scattering on visible matter destroys nucleons, and nucleon decay searches offer a novel avenue for the direct detection of the hidden antibaryonic dark matter sea.

  19. Growth and characterization of isotopically enriched [sup 70]Ge and [sup 74]Ge single crystals

    SciTech Connect (OSTI)

    Itoh, K.

    1992-10-01

    Isotopically enriched [sup 70]Ge and [sup 74]Ge single crystals were successfully gown by a newly developed vertical Bridgman method. The system allows us to reliably grow high purity Ge single crystals of approximately 1 cm[sup 3] volume. To our knowledge, we have grown the first [sup 70]Ge single crystal. The electrically active chemical impurity concentration for both crystals was found to be [approximately]2 [times] cm[sup [minus]3] which is two order of magnitude better that of [sup 74]Ge crystals previously grown by two different groups. Isotopic enrichment of the [sup 70]Ge and the [sup 74]Ge crystals is 96.3% and 96.8%, respectively. The residual chemical impurities present in both crystals were identified as phosphorus, copper, aluminum, and indium. A wide variety of experiments which take advantage of the isotopic purity of our crystals are discussed.

  20. Growth and characterization of isotopically enriched {sup 70}Ge and {sup 74}Ge single crystals

    SciTech Connect (OSTI)

    Itoh, K.

    1992-10-01

    Isotopically enriched {sup 70}Ge and {sup 74}Ge single crystals were successfully gown by a newly developed vertical Bridgman method. The system allows us to reliably grow high purity Ge single crystals of approximately 1 cm{sup 3} volume. To our knowledge, we have grown the first {sup 70}Ge single crystal. The electrically active chemical impurity concentration for both crystals was found to be {approximately}2 {times} cm{sup {minus}3} which is two order of magnitude better that of {sup 74}Ge crystals previously grown by two different groups. Isotopic enrichment of the {sup 70}Ge and the {sup 74}Ge crystals is 96.3% and 96.8%, respectively. The residual chemical impurities present in both crystals were identified as phosphorus, copper, aluminum, and indium. A wide variety of experiments which take advantage of the isotopic purity of our crystals are discussed.

  1. Monolithic Ge-on-Si lasers for integrated photonics

    E-Print Network [OSTI]

    Liu, Jifeng

    We report room temperature Ge-on-Si lasers with direct gap emission at 1590-1610 nm. Modeling of Ge/Si double heterojunction structures, which is supported by experimental results of Ge/Si LEDs, indicates the feasibility ...

  2. Is there a risk from not using GE animals?

    E-Print Network [OSTI]

    Murray, James D.; Maga, Elizabeth A.

    2010-01-01

    Is there a risk from not using GE animals? James D. Murray •rst genetically engi- neered (GE) plants and animals forthe debate often focuses on GE as a technique that is used

  3. Xergy Ships First Breakthrough Water Heater Compressor to GE...

    Energy Savers [EERE]

    Xergy Ships First Breakthrough Water Heater Compressor to GE Xergy Ships First Breakthrough Water Heater Compressor to GE September 15, 2015 - 3:41pm Addthis Xergy Inc. and GE...

  4. Passionate Technologists Wanted at ASME Turbo Expo|GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    who want to learn more about GE and its global Research Centers. For this purpose, the Aero & Thermal Systems groups of GE Global Research and representatives from several GE...

  5. Ge-on-Si laser for silicon photonics

    E-Print Network [OSTI]

    Camacho-Aguilera, Rodolfo Ernesto

    2013-01-01

    Ge-on-Si devices are explored for photonic integration. Importance of Ge in photonics has grown and through techniques developed in our group we demonstrated low density of dislocations (<1x109cm-2) and point defects Ge ...

  6. On the minimum dark matter mass testable by neutrinos from the Sun

    SciTech Connect (OSTI)

    Busoni, Giorgio; Simone, Andrea De; Huang, Wei-Chih E-mail: andrea.desimone@sissa.it

    2013-07-01

    We discuss a limitation on extracting bounds on the scattering cross section of dark matter with nucleons, using neutrinos from the Sun. If the dark matter particle is sufficiently light (less than about 4 GeV), the effect of evaporation is not negligible and the capture process goes in equilibrium with the evaporation. In this regime, the flux of solar neutrinos of dark matter origin becomes independent of the scattering cross section and therefore no constraint can be placed on it. We find the minimum values of dark matter masses for which the scattering cross section on nucleons can be probed using neutrinos from the Sun. We also provide simple and accurate fitting functions for all the relevant processes of GeV-scale dark matter in the Sun.

  7. Understanding of interface structures and reaction mechanisms induced by Ge or GeO diffusion in Al{sub 2}O{sub 3}/Ge structure

    SciTech Connect (OSTI)

    Shibayama, Shigehisa [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan) [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); JSPS, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Kato, Kimihiko; Sakashita, Mitsuo; Takeuchi, Wakana; Taoka, Noriyuki; Nakatsuka, Osamu; Zaima, Shigeaki [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)] [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2013-08-19

    The reaction mechanisms at Al{sub 2}O{sub 3}/Ge interfaces with thermal oxidation through the Al{sub 2}O{sub 3} layer have been investigated. X-ray photoelectron spectroscopy reveals that an Al{sub 6}Ge{sub 2}O{sub 13} layer is formed near the interface, and a GeO{sub 2} layer is formed on the Al{sub 2}O{sub 3} surface, suggesting Ge or GeO diffusion from the Ge surface. It is also clarified that the Al{sub 6}Ge{sub 2}O{sub 13} layer is formed by the different mechanism with a small activation energy of 0.2 eV, compared with the GeO{sub 2} formation limited by oxygen diffusion. Formation of Al-O-Ge bonds due to the AlGeO formation could lead appropriate interface structures with high interface qualities.

  8. Enhancement of thermal stability and water resistance in yttrium-doped GeO{sub 2}/Ge gate stack

    SciTech Connect (OSTI)

    Lu, Cimang, E-mail: cimang@adam.t.u-tokyo.ac.jp; Hyun Lee, Choong; Zhang, Wenfeng; Nishimura, Tomonori; Nagashio, Kosuke; Toriumi, Akira [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656 (Japan); JST, CREST, 7-3-1 Hongo, Tokyo 113-8656 (Japan)

    2014-03-03

    We have systematically investigated the material and electrical properties of yttrium-doped GeO{sub 2} (Y-GeO{sub 2}) on Germanium (Ge). A significant improvement of both thermal stability and water resistance were demonstrated by Y-GeO{sub 2}/Ge stack, compared to that of pure GeO{sub 2}/Ge stack. The excellent electrical properties of Y-GeO{sub 2}/Ge stacks with low D{sub it} were presented as well as enhancement of dielectric constant in Y-GeO{sub 2} layer, which is beneficial for further equivalent oxide thickness scaling of Ge gate stack. The improvement of thermal stability and water resistance are discussed both in terms of the Gibbs free energy lowering and network modification of Y-GeO{sub 2}.

  9. Testimonials - Partnerships in Fuel Cells - GE Global Research...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fuel Cells - GE Global Research Testimonials - Partnerships in Fuel Cells - GE Global Research Addthis An error occurred. Try watching this video on www.youtube.com, or enable...

  10. Work & Life at San Ramon | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    new window) Click to share on Tumblr (Opens in new window) Employee Organizations GE Software Women's Network TBD Celebrations GE Software Technology Conference This event allows...

  11. Rocket Science? No, It's Harder | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    says Juan Albeniz, Business Program Manager, Oil & Gas at GE Global Research Europe. Juan Albeniz, Business Program Manager, Oil & Gas at GE Global Research, Europe Juan...

  12. ME 227 CE 212 MATH 223 GE 210 CMPT 116 ABE 211CHE 210 GE 213# MATH 224

    E-Print Network [OSTI]

    Saskatchewan, University of

    GE 120 ME 227 CE 212 MATH 223 GE 210 CMPT 116 ABE 211CHE 210 GE 213# MATH 224 ABE 295 ABE 212Elective* Elective* AB E 311 ABE 313 ABE 312 GE 348#ABE 323 co-requisite ABE 327 HSS#@ HSS#@ ABE 324 GE 300# ABE 395 4TH YEAR ABE Elec* ABE Elec* ABE Elec*ABE 422 GE 449# Ag Elec* T.E.* T.E.* ABE Elec* Ag Elec

  13. Hollow nuclear matter

    E-Print Network [OSTI]

    Gao-Chan Yong

    2015-12-18

    It is generally considered that an atomic nucleus is always compact. Based on the isospin-dependent Boltzmann nuclear transport model, here I show that large block nuclear matter or excited nuclear matter may both be hollow. And the size of inner bubble in these matter is affected by the charge number of nuclear matter. Existence of hollow nuclear matter may have many implications in nuclear or atomic physics or astrophysics as well as some practical applications.

  14. Hollow nuclear matter

    E-Print Network [OSTI]

    Yong, Gao-Chan

    2015-01-01

    It is generally considered that an atomic nucleus is always compact. Based on the isospin-dependent Boltzmann nuclear transport model, here I show that large block nuclear matter or excited nuclear matter may both be hollow. And the size of inner bubble in these matter is affected by the charge number of nuclear matter. Existence of hollow nuclear matter may have many implications in nuclear or atomic physics or astrophysics as well as some practical applications.

  15. Thermal conductivity of sputtered amorphous Ge films

    SciTech Connect (OSTI)

    Zhan, Tianzhuo; Xu, Yibin; Goto, Masahiro; Tanaka, Yoshihisa; Kato, Ryozo; Sasaki, Michiko; Kagawa, Yutaka [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan)] [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan)

    2014-02-15

    We measured the thermal conductivity of amorphous Ge films prepared by magnetron sputtering. The thermal conductivity was significantly higher than the value predicted by the minimum thermal conductivity model and increased with deposition temperature. We found that variations in sound velocity and Ge film density were not the main factors in the high thermal conductivity. Fast Fourier transform patterns of transmission electron micrographs revealed that short-range order in the Ge films was responsible for their high thermal conductivity. The results provide experimental evidences to understand the underlying nature of the variation of phonon mean free path in amorphous solids.

  16. Energy band alignment of atomic layer deposited HfO{sub 2} oxide film on epitaxial (100)Ge, (110)Ge, and (111)Ge layers

    SciTech Connect (OSTI)

    Hudait, Mantu K.; Zhu Yan [Advanced Devices and Sustainable Energy Laboratory (ADSEL), Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2013-03-21

    Crystallographically oriented epitaxial Ge layers were grown on (100), (110), and (111)A GaAs substrates by in situ growth process using two separate molecular beam epitaxy chambers. The band alignment properties of atomic layer hafnium oxide (HfO{sub 2}) film deposited on crystallographically oriented epitaxial Ge were investigated using x-ray photoelectron spectroscopy (XPS). Valence band offset, {Delta}E{sub v} values of HfO{sub 2} relative to (100)Ge, (110)Ge, and (111)Ge orientations were 2.8 eV, 2.28 eV, and 2.5 eV, respectively. Using XPS data, variation in valence band offset, {Delta}E{sub V}(100)Ge>{Delta}E{sub V}(111)Ge>{Delta}E{sub V}(110)Ge, was obtained related to Ge orientation. Also, the conduction band offset, {Delta}E{sub c} relation, {Delta}E{sub c}(110)Ge>{Delta}E{sub c}(111)Ge>{Delta}E{sub c}(100)Ge related to Ge orientations was obtained using the measured bandgap of HfO{sub 2} on each orientation and with the Ge bandgap of 0.67 eV. These band offset parameters for carrier confinement would offer an important guidance to design Ge-based p- and n-channel metal-oxide field-effect transistor for low-power application.

  17. Dark Matter Through the Neutrino Portal

    E-Print Network [OSTI]

    Adam Falkowski; Jose Juknevich; Jessie Shelton

    2009-08-13

    We consider a model of dark matter whose most prominent signature is a monochromatic flux of TeV neutrinos from the galactic center. As an example of a general scenario, we consider a specific model where the dark matter is a fermion in the adjoint representation of a hidden SU(N) gauge group that confines at GeV energies. The absence of light fermionic states in the dark sector ensures stability of dark matter on cosmological time scales. Dark matter couples to the standard model via the neutrino portal, that is, the singlet operator H L constructed from the Higgs and lepton doublets, which is the lowest dimensional fermionic singlet operator in the standard model. This coupling prompts dark matter decay where the dominant decay channel has one neutrino (and at least one dark glueball) in the final state. Other decay channels with charged standard model particles involve more particles in the final state and are therefore suppressed by phase space. In consequence, the standard indirect detection signals like gamma-ray photons, antiprotons and positrons are suppressed with respect to the neutrino signal. This coupling via the neutrino portal is most robustly constrained by Super-Kamiokande, which restricts the dark matter lifetime to be larger than 10^25 seconds. In the near future, the scenario will be probed by the new generation of neutrino telescopes. ANTARES will be sensitive to a dark matter lifetime of order 10^26 seconds, while IceCube/DeepCore can probe a lifetime as large as 10^27 seconds.

  18. Bulk and surface half-metallicity: The case of D0{sub 3}-type Mn{sub 3}Ge

    SciTech Connect (OSTI)

    Liu, Hao; Gao, G. Y. Hu, Lei; Ni, Yun; Zu, Fengxia; Zhu, Sicong; Wang, Shuling; Yao, K. L.

    2014-01-21

    Motivated by the experimental realization of D0{sub 22}-type Mn{sub 3}Ge (001) films [Kurt et al. Appl. Phys. Lett. 101, 132410 (2012)] and the structural stability of D0{sub 3}-type Heusler alloy Mn{sub 3}Ge [Zhang et al. J. Phys.: Condens. Matter 25, 206006 (2013)], we use the first-principles calculations based on the full potential linearized augmented plane-wave method to investigate the electronic and magnetic properties of D0{sub 3}-type Heusler alloy Mn{sub 3}Ge and its (001) surface. We show that bulk D0{sub 3}-Mn{sub 3}Ge is a half-metallic ferromagnet with the minority-spin energy gap of 0.52?eV and the magnetic moment of 1.00??{sub B} per formula unit. The bulk half-metallicity is preserved at the pure Mn-terminated (001) surface due to the large exchange split, but the MnGe-terminated (001) surface destroys the bulk half-metallicity. We also reveal that the surface stabilities are comparable between the D0{sub 3}-Mn{sub 3}Ge (001) and the experimental D0{sub 22}-Mn{sub 3}Ge (001), which indicates the feasibility to grow the Mn{sub 3}Ge (001) films with D0{sub 3} phase other than D0{sub 22} one. The surface half-metallicity and stability make D0{sub 3}-Mn{sub 3}Ge a promising candidate for spintronic applications.

  19. GE Appliances: Order (2010-CE-2113)

    Broader source: Energy.gov [DOE]

    DOE issued an Order after entering into a Compromise Agreement with General Electric Appliances after finding GE Appliances had failed to certify that certain models of dehumidifiers comply with the applicable energy conservation standards.

  20. Researching NDE, Additive Manufacturing |GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    I never thought I would get the incredible opportunity to become a summer intern at the GE Global Research Center, amongst such brilliant and tenacious individuals. I have been...

  1. GE's Christine Furstoss Named to NACIE

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in Niskayuna, NY, Christine is responsible for working with both R&D leaders at GE's industrial businesses and with strategic partners to set strategy for growth, and to...

  2. Evaluation of Metal Halide, Plasma, and LED Lighting Technologies for a Hydrogen Fuel Cell Mobile Light (H 2 LT)

    SciTech Connect (OSTI)

    Miller, L. B.; Donohoe, S. P.; Jones, M. H.; White, W. A.; Klebanoff, L. E.; Velinsky, S. A.

    2015-04-22

    This article reports on the testing and comparison of a prototype hydrogen fuel cell light tower (H2LT) and a conventional diesel-powered metal halide light trailer for use in road maintenance and construction activities. The prototype was originally outfitted with plasma lights and then with light-emitting diode (LED) luminaires. Light output and distribution, lighting energy efficiency (i.e., efficacy), power source thermal efficiency, and fuel costs are compared. The metal halide luminaires have 2.2 and 3.1 times more light output than the plasma and LED luminaires, respectively, but they require more power/lumen to provide that output. The LED luminaires have 1.6 times better light efficacy than either the metal halide or plasma luminaires. The light uniformity ratios produced by the plasma and LED towers are acceptable. The fuel cell thermal efficiency at the power required to operate the plasma lights is 48%, significantly higher than the diesel generator efficiency of 23% when operating the metal halide lights. Due to the increased efficiency of the fuel cell and the LED lighting, the fuel cost per lumen-hour of the H2LT is 62% of the metal halide diesel light tower assuming a kilogram of hydrogen is twice the cost of a gallon of diesel fuel.

  3. Exclusive $?^0$ electroproduction at $W>2$ GeV with CLAS

    E-Print Network [OSTI]

    I. Bedlinskiy; V. Kubarovsky; S. Niccolai; P. Stoler; K. P. Adhikari; M. D. Anderson; S. Anefalos Pereira; H. Avakian; J. Ball; N. A. Baltzell; M. Battaglieri; V. Batourine; A. S. Biselli; S. Boiarinov; J. Bono; W. J. Briscoe; W. K. Brooks; V. D. Burkert; D. S. Carman; A. Celentano; S. Chandavar; L. Colaneri; P. L. Cole; M. Contalbrigo; O. Cortes; V. Crede; A. D'Angelo; N. Dashyan; R. De Vita; E. De Sanctis; A. Deur; C. Djalali; D. Doughty; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; L. Elouadrhiri; P. Eugenio; G. Fedotov; S. Fegan; J. A. Fleming; T. A. Forest; B. Garillon; M. Gar\\c con; G. Gavalian; N. Gevorgyan; Y. Ghandilyan; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; E. Golovatch; R. W. Gothe; K. A. Griffioen; B. Guegan; L. Guo; K. Hafidi; H. Hakobyan; N. Harrison; M. Hattawy; K. Hicks; M. Holtrop; D. G. Ireland; B. S. Ishkhanov; E. L. Isupov; D. Jenkins; H. S. Jo; K. Joo; D. Keller; M. Khandaker; A. Kim; W. Kim; A. Klein; F. J. Klein; S. Koirala; S. E. Kuhn; S. V. Kuleshov; P. Lenisa; W. I. Levine; K. Livingston; H. Y. Lu; I . J . D. MacGregor; N. Markov; M. Mayer; B. McKinnon; M. Mirazita; V. Mokeev; R. A. Montgomery; C. I. Moody; H. Moutarde; A Movsisyan; C. Munoz Camacho; P. Nadel-Turonski; I. Niculescu; M. Osipenko; A. I. Ostrovidov; L. L. Pappalardo; K. Park; S. Park; E. Pasyuk; E. Phelps; W. Phelps; J. J. Phillips; S. Pisano; O. Pogorelko; J. W. Price; Y. Prok; D. Protopopescu; S. Procureur; A. J. R. Puckett; B. A. Raue; M. Ripani; B. G. Ritchie; A. Rizzo; P. Rossi; P. Roy; F. Sabatié; C. Salgado; D. Schott; R. A. Schumacher; E. Seder; I. Senderovich; Y. G. Sharabian; A. Simonyan; G. D. Smith; D. I. Sober; D. Sokhan; S. S. Stepanyan; S. Strauch; V. Sytnik; W. Tang; Ye Tian; M. Ungaro; A. V. Vlassov; H. Voskanyan; E. Voutier; N. K. Walford; D. Watts; X. Wei; L. B. Weinstein; M. Yurov; N. Zachariou; L. Zana; J. Zhang; Z. W. Zhao; I. Zonta; for the CLAS Collaboration

    2014-05-05

    Exclusive neutral-pion electroproduction ($ep\\to e^\\prime p^\\prime \\pi^0$) was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4\\sigma/dtdQ^2dx_Bd\\phi_\\pi$ and structure functions $\\sigma_T+\\epsilon\\sigma_L, \\sigma_{TT}$ and $\\sigma_{LT}$ as functions of $t$ were obtained over a wide range of $Q^2$ and $x_B$. The data are compared with Regge and handbag theoretical calculations. Analyses in both frameworks find that a large dominance of transverse processes is necessary to explain the experimental results. For the Regge analysis it is found that the inclusion of vector meson rescattering processes is necessary to bring the magnitude of the calculated and measured structure functions into rough agreement. In the handbag framework, there are two independent calculations, both of which appear to roughly explain the magnitude of the structure functions in terms of transversity generalized parton distributions.

  4. GE Announces Vic Abate as New Chief Technology Officer | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Industrial Internet and Brilliant Factory. This transition marks another chapter in GE's transformation to become the world's premiere Digital Industrial company. Enabled by a...

  5. Be a part of something bigger than yourself GE Healthcare

    E-Print Network [OSTI]

    Rimon, Elon

    Be a part of something bigger than yourself GE Healthcare Position: Mechanical Engineer as a contractor · Working at GE site at Tirat-Carmel. · Start: immediately · Duration 6-10 months, with optional elongation. ElgemsMoked@ge.com-CV www.gehealthcare.com We are GE Healthcare, a $17 billion division

  6. Significant Gamma Lines from Inert Higgs Dark Matter

    E-Print Network [OSTI]

    Michael Gustafsson; Erik Lundstrom; Lars Bergstrom; Joakim Edsjo

    2007-10-05

    One way to unambiguously confirm the existence of particle dark matter and determine its mass would be to detect its annihilation into monochromatic gamma-rays in upcoming telescopes. One of the most minimal models for dark matter is the inert doublet model, obtained by adding another Higgs doublet with no direct coupling to fermions. For a mass between 40 and 80 GeV, the lightest of the new inert Higgs particles can give the correct cosmic abundance of cold dark matter in agreement with current observations. We show that for this scalar dark matter candidate, the annihilation signal of monochromatic \\gamma\\gamma and Z\\gamma final states would be exceptionally strong. The energy range and rates for these gamma-ray line signals make them ideal to search for with the soon upcoming GLAST satellite.

  7. Probing Light Dark Matter via Evaporation from the Sun

    E-Print Network [OSTI]

    Chris Kouvaris

    2015-06-13

    Dark matter particles can be captured by the sun with rates that depend on the dark matter mass and the DM-nucleon cross section. However, for masses below $\\sim 3.3$ GeV, the captured dark matter particles evaporate, leading to an equilibrium where the rate of captured particles is equal to the rate of evaporating ones. Unlike dark matter particles from the halo, the evaporating dark matter particles have velocities that are not limited to values below the escape velocity of the galaxy. Despite the fact that high velocities are exponentially suppressed, I demonstrate here that current underground detectors have the possibility to probe/constrain low dark matter parameter space by (not)-observing the high energy tail of the evaporating dark matter particles from the sun. I also show that the functional form of the differential rate of counts with respect to the recoil energy in earth based detectors can identify precisely the mass and the cross section of the dark matter particle in this case.

  8. Cosmic antiprotons as a probe for neutralino dark matter?

    E-Print Network [OSTI]

    Lars Bergstrom; Joakim Edsjo; Piero Ullio

    1999-06-02

    The flux of cosmic ray antiprotons from neutralino annihilations in the galactic halo is computed for a large sample of models in the Minimal Supersymmetric extension of the Standard Model. We also revisit the problem of estimating the background of low-energy cosmic ray induced secondary antiprotons, taking into account their subsequent interactions (and energy loss) and the presence of nuclei in the interstellar matter. We point out that in some cases the optimal kinetic energy to search for a signal from supersymmetric dark matter is above several GeV, rather than the traditional sub-GeV region. The large astrophysical uncertainties involved do not allow the exclusion of any of the MSSM models we consider, on the basis of current data.

  9. Direct Dark Matter Searches with CDMS and XENON

    E-Print Network [OSTI]

    Kaixuan Ni; Laura Baudis

    2006-11-09

    The Cryogenic Dark Matter Search (CDMS) and XENON experiments aim to directly detect dark matter in the form of weakly interacting massive particles (WIMPs) via their elastic scattering on the target nuclei. The experiments use different techniques to suppress background event rates to the minimum, and at the same time, to achieve a high WIMP detection rate. The operation of cryogenic Ge and Si crystals of the CDMS-II experiment in the Soudan mine yielded the most stringent spin-independent WIMP-nucleon cross-section (~10^{-43} cm^2) at a WIMP mass of 60 GeV/c^2. The two-phase xenon detector of the XENON10 experiment is currently taking data in the Gran Sasso underground lab and promising preliminary results were recently reported. Both experiments are expected to increase their WIMP sensitivity by a one order of magnitude in the scheduled science runs for 2007.

  10. Predictions on mass of Higgs portal scalar dark matter from Higgs inflation and flat potential

    E-Print Network [OSTI]

    Yuta Hamada; Hikaru Kawai; Kin-ya Oda

    2015-01-25

    We consider the Higgs portal $Z_2$ scalar model as the minimal extension of the Standard Model (SM) to incorporate the dark matter. We find that the dark matter mass is bounded to be lighter than 1000\\,GeV within the framework that we have proposed earlier, where the Higgs inflation occurs above the SM cutoff $\\Lambda$, thanks to the fact that the Higgs potential becomes much smaller than its typical value in the SM: $V\\ll\\Lambda^4$. We can further fix the dark matter mass to be $400\\text{GeV}< m_\\text{DM}<470\\text{GeV}$ if we impose that the cutoff is at the string scale $\\Lambda\\sim10^{17}\\text{GeV}$ and that the Higgs potential becomes flat around $\\Lambda$, as is required by the multiple point principle or by the Higgs inflation at the critical point. This prediction is testable by the dark matter detection experiments in the near future. In this framework, the dark matter and top quark masses are strongly correlated, which is also testable.

  11. Exploring nu signals in dark matter detectors

    E-Print Network [OSTI]

    Roni Harnik; Joachim Kopp; Pedro A. N. Machado

    2015-08-03

    We investigate standard and non-standard solar neutrino signals in direct dark matter detection experiments. It is well known that even without new physics, scattering of solar neutrinos on nuclei or electrons is an irreducible background for direct dark matter searches, once these experiments each the ton scale. Here, we entertain the possibility that neutrino interactions are enhanced by new physics, such as new light force carriers (for instance a "dark photon") or neutrino magnetic moments. We consider models with only the three standard neutrino flavors, as well as scenarios with extra sterile neutrinos. We find that low-energy neutrino--electron and neutrino--nucleus scattering rates can be enhanced by several orders of magnitude, potentially enough to explain the event excesses observed in CoGeNT and CRESST. We also investigate temporal modulation in these neutrino signals, which can arise from geometric effects, oscillation physics, non-standard neutrino energy loss, and direction-dependent detection efficiencies. We emphasize that, in addition to providing potential explanations for existing signals, models featuring new physics in the neutrino sector can also be very relevant to future dark matter searches, where, on the one hand, they can be probed and constrained, but on the other hand, their signatures could also be confused with dark matter signals.

  12. Asymmetric dark matter

    SciTech Connect (OSTI)

    Kumar, Jason

    2014-06-24

    We review the theoretical framework underlying models of asymmetric dark matter, describe astrophysical constraints which arise from observations of neutron stars, and discuss the prospects for detecting asymmetric dark matter.

  13. Design of programmable matter

    E-Print Network [OSTI]

    Knaian, Ara N. (Ara Nerses), 1977-

    2008-01-01

    Programmable matter is a proposed digital material having computation, sensing, actuation, and display as continuous properties active over its whole extent. Programmable matter would have many exciting applications, like ...

  14. UC IRVINE GENERAL EDUCATION (GE) REQUIREMENT AND APPROVED GE COURSES, 201213 Includes course titles and Schedule of Classes designations

    E-Print Network [OSTI]

    Loudon, Catherine

    UC IRVINE GENERAL EDUCATION (GE) REQUIREMENT AND APPROVED GE COURSES, 2012­13 Includes course titles and Schedule of Classes designations GENERAL EDUCATION (GE) REQUIREMENT UCI is committed undergraduates complete a set of general education (GE) requirements. General education courses introduce

  15. 2009-10 Princeton Global Scholar Ge Zhaoguang. Professor Ge is the founding director of the National Institute for Advanced

    E-Print Network [OSTI]

    2009-10 Princeton Global Scholar Ge Zhaoguang. Professor Ge is the founding director, and emendation of all sorts of newly discovered texts (mostly found at archaeological sites). Professor Ge University, Professor Ge taught at Tsinghua University for a number of years. He is known for many important

  16. Measurement of the direct energy gap of coherently strained SnxGe1x Ge,,001... heterostructures

    E-Print Network [OSTI]

    Atwater, Harry

    Measurement of the direct energy gap of coherently strained SnxGe1Àx ÕGe,,001... heterostructures The direct energy gap has been measured for coherently strained SnxGe1 x alloys on Ge 001 substrates with 0 for coherently strained SnxGe1 x alloys indicates a large alloy contribution and a small strain contribution

  17. GE Advising & Registration Students FT Faculty PT Faculty Admin Unit 4 Other Staff Students have access to quality GE advising

    E-Print Network [OSTI]

    de Lijser, Peter

    GE Advising & Registration Students FT Faculty PT Faculty Admin Unit 4 Other Staff Students have access to quality GE advising 9% 13% 11% 13% 10% 8% Faculty can easily advise students on GE requirements 10% 18% 9% 24% 33% 11% Staff academic advisors can easily advise students on GE requirements 8% 11

  18. Hot-dark matter, cold dark matter and accelerating universe

    E-Print Network [OSTI]

    Abbas Farmany; Amin Farmany; Mohammad Mahmoodi

    2006-07-07

    The Friedman equation is solved for a universe contains hotdark matter and cold dark matter. In this scenario, hot-dark matter drives an accelerating universe no cold dark matter.

  19. Dark Matter and Cosmic Rays from Light Gauginos

    E-Print Network [OSTI]

    Glennys R. Farrar

    1997-04-13

    An attractive class of SUSY-breaking mechanisms predicts a photino mass of order 1 GeV. Relic photinos can naturally account for the observed dark matter. Detection of these light photinos is discussed and contrasted with conventional WIMPs. In this scenario the gluino mass is about 100 MeV. The lightest gluino-containing baryon could account for the recently observed ultra-high energy cosmic rays, which violate the GZK bound.

  20. Hot and Cold Dark Matter Search with GENIUS

    E-Print Network [OSTI]

    Laura Baudis; Alexander Dietz; Gerd Heusser; Hans Volker Klapdor-Kleingrothaus; Bela Majorovits; Herbert Strecker

    2000-05-30

    GENIUS is a proposal for a large volume detector to search for rare events. An array of 40-400 'naked' HPGe detectors will be operated in a tank filled with ultra-pure liquid nitrogen. After a description of performed technical studies of detector operation in liquid nitrogen and of Monte Carlo simulations of expected background components, the potential of GENIUS for detecting WIMP dark matter, the neutrinoless double beta decay in 76-Ge and low-energy solar neutrinos is discussed.

  1. Isospin-violating dark matter from a double portal

    SciTech Connect (OSTI)

    Bélanger, Geneviève; Goudelis, Andreas; Park, Jong-Chul; Pukhov, Alexander E-mail: andreas.goudelis@lapth.cnrs.fr E-mail: pukhov@lapth.cnrs.fr

    2014-02-01

    We study a simple model that can give rise to isospin-violating interactions of Dirac fermion asymmetric dark matter to protons and neutrons through the interference of a scalar and U(1)' gauge boson contribution. The model can yield a large suppression of the elastic scattering cross section off Xenon relative to Silicon thus reconciling CDMS-Si and LUX results while being compatible with LHC findings on the 126 GeV Higgs, electroweak precision tests and flavour constraints.

  2. Relaxation and recombination processes in Ge/SiGe multiple quantum wells

    SciTech Connect (OSTI)

    Gatti, E., E-mail: gatti@mater.unimib.it; Giorgioni, A., E-mail: gatti@mater.unimib.it; Grilli, E., E-mail: gatti@mater.unimib.it; Guzzi, M., E-mail: gatti@mater.unimib.it [L-NESS and Università di Milano-Bicocca, Dip. di Scienza dei Materiali, via Cozzi 53, 20125 Milano (Italy); Chrastina, D.; Isella, G. [L-NESS and Politecnico di Milano, Dip. di Fisica, via Anzani 42, 22100 Como (Italy); Chernikov, A.; Kolata, K.; Bornwasser, V.; Köster, N. S.; Woscholski, R.; Chatterjee, S. [Faculty of Physics and Materials Sciences Center, Philipps-Universität, Renthof 5, 35032 Marburg (Germany)

    2013-12-04

    The carrier dynamics that occurs in Ge/SiGe QWs when electrons are excited to confined states at ? is studied by means of optical spectroscopy at different lattice temperatures. The typical times for the different relaxation and recombination processes are given and discussed.

  3. Fermionic dark matter with pseudo-scalar Yukawa interaction

    SciTech Connect (OSTI)

    Ghorbani, Karim

    2015-01-01

    We consider a renormalizable extension of the standard model whose fermionic dark matter (DM) candidate interacts with a real singlet pseudo-scalar via a pseudo-scalar Yukawa term while we assume that the full Lagrangian is CP-conserved in the classical level. When the pseudo-scalar boson develops a non-zero vacuum expectation value, spontaneous CP-violation occurs and this provides a CP-violated interaction of the dark sector with the SM particles through mixing between the Higgs-like boson and the SM-like Higgs boson. This scenario suggests a minimal number of free parameters. Focusing mainly on the indirect detection observables, we calculate the dark matter annihilation cross section and then compute the DM relic density in the range up to m{sub DM} = 300 GeV.We then find viable regions in the parameter space constrained by the observed DM relic abundance as well as invisible Higgs decay width in the light of 125 GeV Higgs discovery at the LHC. We find that within the constrained region of the parameter space, there exists a model with dark matter mass m{sub DM} ? 38 GeV annihilating predominantly into b quarks, which can explain the Fermi-LAT galactic gamma-ray excess.

  4. Atomic ionization by keV-scale pseudoscalar dark-matter particles

    SciTech Connect (OSTI)

    Dzuba, V. A.; Flambaum, V. V.; Pospelov, M.

    2010-05-15

    Using the relativistic Hartree-Fock approximation, we calculate the rates of atomic ionization by absorption of pseudoscalar particles in the mass range from 10 to {approx}50 keV. We present numerical results for atoms relevant for the direct dark-matter searches (e.g. Ar, Ge, I and Xe), as well as the analytical formula which fits numerical calculations with few per cent accuracy and may be used for multielectron atoms, molecules and condensed matter systems.

  5. Measuring 10-1000 GeV Cosmic Ray Electrons with GLAST/LAT

    E-Print Network [OSTI]

    Alexander A. Moiseev; Jonathan F. Ormes; Igor V. Moskalenko

    2007-06-06

    We present here the capabilities of the GLAST Large Area Telescope to detect cosmic ray high-energy (HE) electrons in the energy range from 10 GeV to 1 TeV. We also discuss the science topics that can be investigated with HE electron data and quantify the results with LAT instrument simulations. The science topics include CR propagation, calibration of the IC gamma-ray model, testing hypotheses regarding the origin of HE energy cosmic-ray electrons, searching for any signature of Kaluza Klein Dark Matter annihilation, and measuring the HE electron anisotropy. We expect to detect ~ 107 electrons above 20 GeV per year of LAT operation.

  6. Big Questions: Dark Matter

    SciTech Connect (OSTI)

    Lincoln, Don

    2013-12-05

    Carl Sagan's oft-quoted statement that there are "billions and billions" of stars in the cosmos gives an idea of just how much "stuff" is in the universe. However scientists now think that in addition to the type of matter with which we are familiar, there is another kind of matter out there. This new kind of matter is called "dark matter" and there seems to be five times as much as ordinary matter. Dark matter interacts only with gravity, thus light simply zips right by it. Scientists are searching through their data, trying to prove that the dark matter idea is real. Fermilab's Dr. Don Lincoln tells us why we think this seemingly-crazy idea might not be so crazy after all.

  7. Big Questions: Dark Matter

    ScienceCinema (OSTI)

    Lincoln, Don

    2014-08-07

    Carl Sagan's oft-quoted statement that there are "billions and billions" of stars in the cosmos gives an idea of just how much "stuff" is in the universe. However scientists now think that in addition to the type of matter with which we are familiar, there is another kind of matter out there. This new kind of matter is called "dark matter" and there seems to be five times as much as ordinary matter. Dark matter interacts only with gravity, thus light simply zips right by it. Scientists are searching through their data, trying to prove that the dark matter idea is real. Fermilab's Dr. Don Lincoln tells us why we think this seemingly-crazy idea might not be so crazy after all.

  8. Hunting for dark matter subhalos among the Fermi-LAT sources with VERITAS

    E-Print Network [OSTI]

    Nieto, Daniel

    2015-01-01

    The distribution of dark matter in the Galaxy, according to state-of-the-art simulations, shows not only a smooth halo component but also a rich substructure where a hierarchy of dark matter subhalos of different masses is found. We present a search for potential dark matter subhalos in our Galaxy exploiting the high (HE, 100 MeV -- 100 GeV) and very-high-energy (VHE, >100 GeV) gamma-ray bands. We assume a scenario where the dark matter is composed of weakly interacting massive particles of mass over 100 GeV, and is capable of self-annihilation into standard model products. Under such a hypothesis, most of the photons created by the annihilation of dark matter particles are predicted to lay in the HE gamma-ray band, where the Fermi-Large Area Telescope is the most sensitive instrument to date. However, the distinctive spectral cut-off located at the dark matter particle mass is expected in the VHE gamma-ray band, thus making imaging atmospheric Cherenkov telescopes like VERITAS the best suited instruments for...

  9. Systematic uncertainties from halo asphericity in dark matter searches

    SciTech Connect (OSTI)

    Bernal, Nicolás; Forero-Romero, Jaime E.; Garani, Raghuveer; Palomares-Ruiz, Sergio E-mail: je.forero@uniandes.edu.co E-mail: sergio.palomares.ruiz@ific.uv.es

    2014-09-01

    Although commonly assumed to be spherical, dark matter halos are predicted to be non-spherical by N-body simulations and their asphericity has a potential impact on the systematic uncertainties in dark matter searches. The evaluation of these uncertainties is the main aim of this work, where we study the impact of aspherical dark matter density distributions in Milky-Way-like halos on direct and indirect searches. Using data from the large N-body cosmological simulation Bolshoi, we perform a statistical analysis and quantify the systematic uncertainties on the determination of local dark matter density and the so-called J factors for dark matter annihilations and decays from the galactic center. We find that, due to our ignorance about the extent of the non-sphericity of the Milky Way dark matter halo, systematic uncertainties can be as large as 35%, within the 95% most probable region, for a spherically averaged value for the local density of 0.3-0.4 GeV/cm {sup 3}. Similarly, systematic uncertainties on the J factors evaluated around the galactic center can be as large as 10% and 15%, within the 95% most probable region, for dark matter annihilations and decays, respectively.

  10. Ge/SiGe quantum wells on Si(111): Growth, structural, and optical properties

    SciTech Connect (OSTI)

    Gatti, E., E-mail: eleonora.gatti@mater.unimib.it; Pezzoli, F.; Grilli, E. [L-NESS and Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, via Cozzi 55, I-20125 Milano (Italy); Isa, F.; Chrastina, D.; Isella, G. [L-NESS and Dipartimento di Fisica, Politecnico di Milano, Polo di Como, via Anzani 42, I - 22100 Como (Italy); Müller Gubler, E. [Electron Microscopy Center of ETH Zürich (EMEZ), August-Piccard-Hof 1, CH-8093 Zürich (Switzerland)

    2014-07-28

    The epitaxial growth of Ge/Si{sub 0.15}Ge{sub 0.85} multiple quantum wells (MQWs) on Si(111) substrates is demonstrated. A 3??m thick reverse, double-step virtual substrate with a final composition of Si{sub 0.10}Ge{sub 0.90} has been employed. High resolution XRD, TEM, AFM and defect etching analysis has been used for the study of the structural properties of the buffer and of the QWs. The QW stack is characterized by a threading dislocation density of about 3?×?10{sup 7?}cm{sup ?2} and an interdiffusion layer at the well/barrier interface of 2.1?nm. The quantum confined energy levels of this system have been calculated using the k·p and effective mass approximation methods. The Ge/Si{sub 0.15}Ge{sub 0.85} MQWs have been characterized through absorption and photoluminescence measurements. The optical spectra have been compared with those of Ge/Si{sub 0.15}Ge{sub 0.85} QWs grown on Si(001) through a thick graded virtual substrate.

  11. Optical Link on Silicon Employing Ge/SiGe Quantum Well Structures Onur Fidaner, Ali K. Okyay, Jonathan E. Roth, Rebecca K. Scheavitz, Yu-Hsuan Kuo*

    E-Print Network [OSTI]

    Miller, David A. B.

    Optical Link on Silicon Employing Ge/SiGe Quantum Well Structures Onur Fidaner, Ali K. Okyay University, Taipei, Taiwan Abstract: We demonstrate an optical link on silicon employing Ge/SiGe quantum well of the quantum-confined Stark effect (QCSE) on silicon using Ge/SiGe quantum wells opened up the possibility

  12. 23 6 12 8:00 III-V/Ge CMOS

    E-Print Network [OSTI]

    Katsumoto, Shingo

    23 6 12 8:00 - 1 - 1. : III-V/Ge CMOS ~ 200%~ 2. : III-V (Ge) III-V/Ge CMOS (Si) 200% III-V/Ge CMOS 200% III-V/Ge CMOS () () () () III-V III-V/Ge CMOS (1) III-V Ge III-V/Ge CMOS (2) III-V-OI MOSFET (3) III-V/Ge CMOS "2011 Symposia on VLSI

  13. A Simple Recipe for the 111 and 128 GeV Lines

    E-Print Network [OSTI]

    JiJi Fan; Matthew Reece

    2013-08-03

    Recently evidence for gamma ray lines at energies of approximately 111 and 128 GeV has been found in Fermi-LAT data from the center of the galaxy and from unassociated point sources. Many explanations in terms of dark matter particle pairs annihilating to gamma gamma and gamma Z have been suggested, but these typically require very large couplings or mysterious coincidences in the masses of several new particles to fit the signal strength. We propose a simple novel explanation in which dark matter is part of a multiplet of new states which all have mass near 260 GeV as a result of symmetry. Two dark matter particles annihilate to a pair of neutral particles in this multiplet which subsequently decay to gamma gamma and gamma Z. For example, one may have a triplet of pseudo-Nambu-Goldstone bosons, charged pions and a neutral pion, where the charged pions are stabilized by their charge under a new U(1) symmetry and the slightly lighter neutral pion state decays to gamma gamma and gamma Z. The symmetry structure of such a model explains the near degeneracy in masses needed for the resulting photons to have a line-like shape and the large observed flux. The tunable lifetime of the neutral state allows such models to go unseen at direct detection or collider experiments that can constrain most other explanations. However, nucleosynthesis constraints on the neutral pion lifetime fix a minimum necessary coupling between the new multiplet and the Standard Model. The spectrum is predicted to be not a line but a box with a width of order a few GeV, smaller than but on the order of the Fermi-LAT resolution.

  14. Higgs inflation and Higgs portal dark matter with right-handed neutrinos

    E-Print Network [OSTI]

    Naoyuki Haba; Hiroyuki Ishida; Ryo Takahashi

    2015-05-02

    We investigate the Higgs inflation and the Higgs portal dark matter with the right-handed neutrino. The dark matter and the right-handed neutrino in the Higgs inflation play important roles in explaining the recent experimental results of the Higgs and top masses, and the cosmic microwave background by BICEP2 at the same time. This inflation model predicts $805~{\\rm GeV} \\lesssim m_{\\rm DM} \\lesssim1220~{\\rm GeV}$ for the DM mass, $1.05 \\times10^{14}~{\\rm GeV} \\lesssim M_R \\lesssim 2.04 \\times10^{14}~{\\rm GeV}$ for the right-handed neutrino mass, and $8.42 \\lesssim \\xi \\lesssim 12.4$ for the non-minimal coupling within $m_H=125.6 \\pm 0.35~{\\rm GeV}$ for the Higgs and $M_t=173.34 \\pm 0.76~{\\rm GeV}$ for the top masses.

  15. Photonic dark matter portal revisited

    E-Print Network [OSTI]

    S. A. Alavi; F S Kazemian

    2015-11-18

    In our previous paper [1], we studied a model of dark matter (DM) in which the hidden sector interacts with standard model particles via a hidden photonic portal (HP). We investigated the effects of this new interaction on the hydrogen atom and obtained an upper bound for the coupling of the model. In this work, we study the effects of HP on two interesting exotic atoms namely muonium and positronium. We obtain a tighter upper limit on the coupling. We also calculate the change (shift) in the Aharonov-Bohm phase due to HP and find that the phase shift is negligibly small (for DM particles mass in the GeV range). Recently a 3.5 keV X ray line signal observed in the spectrum of 73 galaxy clusters, reported by the XXM-Newton X ray observatory. Since in HP model the DM particles can decay directly into photons, so we finally calculate the value of the coupling constant f using the condition Delta E=3.5 keV.

  16. DEAP-3600 Dark Matter Search

    E-Print Network [OSTI]

    P. -A. Amaudruz; M. Batygov; B. Beltran; J. Bonatt; M. G. Boulay; B. Broerman; J. F. Bueno; A. Butcher; B. Cai; M. Chen; R. Chouinard; B. T. Cleveland; K. Dering; J. DiGioseffo; F. Duncan; T. Flower; R. Ford; P. Giampa; P. Gorel; K. Graham; D. R. Grant; E. Guliyev; A. L. Hallin; M. Hamstra; P. Harvey; C. J. Jillings; M. Ku?niak; I. Lawson; O. Li; P. Liimatainen; P. Majewski; A. B. McDonald; T. McElroy; K. McFarlane; J. Monroe; A. Muir; C. Nantais; C. Ng; A. J. Noble; C. Ouellet; K. Palladino; P. Pasuthip; S. J. M. Peeters; T. Pollmann; W. Rau; F. Retière; N. Seeburn; K. Singhrao; P. Skensved; B. Smith; T. Sonley; J. Tang; E. Vázquez-Jáuregui; L. Veloce; J. Walding; M. Ward

    2014-10-27

    The DEAP-3600 experiment is located 2 km underground at SNOLAB, in Sudbury, Ontario. It is a single-phase detector that searches for dark matter particle interactions within a 1000-kg fiducial mass target of liquid argon. A first generation prototype detector (DEAP-1) with a 7-kg liquid argon target mass demonstrated a high level of pulse-shape discrimination (PSD) for reducing $\\beta$/$\\gamma$ backgrounds and helped to develop low radioactivity techniques to mitigate surface-related $\\alpha$ backgrounds. Construction of the DEAP-3600 detector is nearly complete and commissioning is starting in 2014. The target sensitivity to spin-independent scattering of Weakly Interacting Massive Particles (WIMPs) on nucleons of 10$^{-46}$ cm$^2$ will allow one order of magnitude improvement in sensitivity over current searches at 100 GeV WIMP mass. This paper presents an overview and status of the DEAP-3600 project and discusses plans for a future multi-tonne experiment, DEAP-50T.

  17. Measurement of the neutron-capture cross section of ??Ge and ??Ge below 15 MeV and its relevance to 0??? decay searches of ??Ge

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bhike, Megha; Fallin, B.; Tornow, W.

    2015-02-01

    The neutron radiative-capture cross section of ??Ge was measured between 0.4 and 14.8 MeV using the activation technique. Germanium samples with the isotopic abundance of ~86% ??Ge and ~14% ??Ge used in the 0??? searches by the GERDA and Majorana Collaborations were irradiated with monoenergetic neutrons produced at eleven energies via the ³H(p,n)³He, ²H(d,n)³He and ³H(d,n)?He reactions. Previously, data existed only at thermal energies and at 14 MeV. As a by-product, capture cross-section data were also obtained for ??Ge at neutron energies below 8 MeV. Indium and gold foils were irradiated simultaneously for neutron fluence determination. High-resolution ?-ray spectroscopy wasmore »used to determine the ?-ray activity of the daughter nuclei of interest. For the ??Ge total capture cross section the present data are in good agreement with the TENDL-2013 model calculations and the ENDF/B-VII.1 evaluations, while for the ??Ge(n,?)??Ge reaction, the present data are about a factor of two larger than predicted. It was found that the ??Ge(n,?)??Ge yield in the High-Purity Germanium (HPGe) detectors used by the GERDA and Majorana Collaborations is only about a factor of two smaller than the ??Ge(n,?)??Ge yield due to the larger cross section of the former reaction.« less

  18. Phase transitions in Ge-Sb phase change materials

    SciTech Connect (OSTI)

    Raoux, Simone; Virwani, Kumar; Hitzbleck, Martina; Salinga, Martin; Madan, Anita; Pinto, Teresa L.

    2009-03-15

    Thin films of the phase change material Ge-Sb with Ge concentrations between 7.3 and 81.1 at. % were deposited by cosputtering from elemental targets. Their crystallization behavior was studied using time-resolved x-ray diffraction, Auger electron spectroscopy, differential scanning calorimetry, x-ray reflectivity, profilometry, optical reflectivity, and resistivity versus temperature measurements. It was found that the crystallization temperature increases with Ge content. Calculations of the glass transition temperature (which is a lower limit for the crystallization temperature T{sub x}) also show an increase with Ge concentration closely tracking the measured values of T{sub x}. For low Ge content samples, Sb x-ray diffraction peaks occurred during a heating ramp at lower temperature than Ge diffraction peaks. The appearance of Ge peaks is related to Ge precipitation and agglomeration. For Ge concentrations of 59.3 at. % and higher, Sb and Ge peaks occurred at the same temperature. Upon crystallization, film mass density and optical reflectivity increase as well as electrical contrast (ratio of resistivity in amorphous phase to crystalline phase) all showed a maximum for the eutectic alloy (14.5 at. % Ge). For the alloy with 59.3 at. % Ge there was very little change in any of these parameters, while the alloy with 81.1 at. % Ge behaved opposite to a typical phase change alloy and showed reduced mass density and reflectivity and increased resistivity.

  19. Updated 8/28/2014 New GE Requirements & Environmental Studies Advising

    E-Print Network [OSTI]

    Updated 8/28/2014 New GE Requirements & Environmental Studies Advising Course Concentration(s) Lower Division GE Upper Division GE Overlay(s) AIS 310

  20. GE Lighting Solutions: Order (2013-SE-4901)

    Broader source: Energy.gov [DOE]

    DOE ordered General Electric Lighting Solutions, LLC to pay a $5,360 civil penalty after finding GE Lighting Solutions had manufactured and distributed in commerce in the U.S. 30 units of basic model DR4-RTFB-23B and 177 units (of which 85 units remain in inventory) of basic model DR4-RTFB-77A-002, noncompliant traffic signal modules.

  1. Viscosity Measurement G.E. Leblanc

    E-Print Network [OSTI]

    Kostic, Milivoje M.

    30 Viscosity Measurement G.E. Leblanc McMaster University R.A. Secco The University of Western and Non-Newtonian Fluids l Dimensions and Units of Viscosity l Viscometer Types l Capillary M. Kostic must be supplied (1) to create viscous flow units by breaking bonds between atoms and molecules, and (2

  2. Young Pulsars and the Galactic Center GeV Gamma-ray Excess

    E-Print Network [OSTI]

    Ryan M. O'Leary; Matthew D. Kistler; Matthew Kerr; Jason Dexter

    2015-04-09

    Studies of Fermi data indicate an excess of GeV gamma rays around the Galactic center (GC), possibly due to dark matter. We show that young gamma-ray pulsars can yield a similar signal. First, a high concentration of GC supernovae naturally leads to a population of kicked pulsars symmetric about the GC. Second, while very-young pulsars with soft spectra reside near the Galactic plane, pulsars with spectra that have hardened with age accumulate at larger angles. This combination, including unresolved foreground pulsars, traces the morphology and spectrum of the Excess.

  3. Young Pulsars and the Galactic Center GeV Gamma-ray Excess

    E-Print Network [OSTI]

    O'Leary, Ryan M; Kerr, Matthew; Dexter, Jason

    2015-01-01

    Studies of Fermi data indicate an excess of GeV gamma rays around the Galactic center (GC), possibly due to dark matter. We show that young gamma-ray pulsars can yield a similar signal. First, a high concentration of GC supernovae naturally leads to a population of kicked pulsars symmetric about the GC. Second, while very-young pulsars with soft spectra reside near the Galactic plane, pulsars with spectra that have hardened with age accumulate at larger angles. This combination, including unresolved foreground pulsars, traces the morphology and spectrum of the Excess.

  4. Strangelet search in Pb-Pb interactions at 158 GeV/{ital c} per nucleon

    SciTech Connect (OSTI)

    Appelquist, G.; Baglin, C.; Beringer, J.; Bohm, C.; Borer, K.; Bussiere, A.; Dittus, F.; Elsener, K.; Frei, D.; Gorodetzky, P.; Guillaud, J.P.; Hugentobler, E.; Klingenberg, R.; Linden, T.; Lohmann, K.D.; Moser, U.; Pal, T.; Pretzl, K.; Schacher, J.; Sellden, B.; Stoffel, F.; Tuominiemi, J.; Zhang, Q.P.

    1996-05-01

    The NA52 experiment searches for long-lived massive strange quark matter particles, so-called {ital strangelets}, produced in Pb-Pb collisions at a beam momentum of {ital p}{sub lab}=158 AGeV/{ital c}. Upper limits for the production of strangelets at zero degree production angle covering a mass to charge ratio up to 120 GeV/{ital c}{sup 2} and lifetimes {ital t}{sub lab}{approx_gt}1.2 {mu}s are given. The data presented here were taken during the 1994 lead beam running period at CERN. {copyright} {ital 1996 The American Physical Society.}

  5. In Wino Veritas? Indirect Searches Shed Light on Neutralino Dark Matter

    E-Print Network [OSTI]

    JiJi Fan; Matthew Reece

    2013-07-16

    Indirect detection constraints on gamma rays (both continuum and lines) have set strong constraints on wino dark matter. By combining results from Fermi-LAT and HESS, we show that: light nonthermal wino dark matter is strongly excluded; thermal wino dark matter is allowed only if the Milky Way dark matter distribution has a significant (>~0.4 kpc) core; and for plausible NFW and Einasto distributions the entire range of wino masses from 100 GeV up to 3 TeV can be excluded. The case of light, nonthermal wino dark matter is particularly interesting in scenarios with decaying moduli that reheat the universe to a low temperature. Typically such models have been discussed for low reheating temperatures, not far above the BBN bound of a few MeV. We show that constraints on the allowed wino relic density push such models to higher reheating temperatures and hence heavier moduli. Even for a flattened halo model consisting of an NFW profile with constant-density core inside 1 kpc and a density near the sun of 0.3 GeV/cm^3, for 150 GeV winos current data constrains the reheat temperature to be above 1.4 GeV. As a result, for models in which the wino mass is a loop factor below the gravitino mass, the data favor moduli that are more than an order of magnitude heavier than the gravitino. We discuss some of the sobering implications of this result for the status of supersymmetry. We also comment on other neutralino dark matter scenarios, in particular the case of mixed bino/higgsino dark matter. We show that in this case, direct and indirect searches are complementary to each other and could potentially cover most of the parameter space.

  6. Matter: Space without Time

    E-Print Network [OSTI]

    Yousef Ghazi-Tabatabai

    2012-11-19

    While Quantum Gravity remains elusive and Quantum Field Theory retains the interpretational difficulties of Quantum Mechanics, we have introduced an alternate approach to the unification of particles, fields, space and time, suggesting that the concept of matter as space without time provides a framework which unifies matter with spacetime and in which we anticipate the development of complete theories (ideally a single unified theory) describing observed 'particles, charges, fields and forces' solely with the geometry of our matter-space-time universe.

  7. Effects of Ge replacement in GeTe by [Ag+Sb] on thermoelectric...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in GeTe by Ag+Sb on thermoelectric properties and NMR spectra Requirements for student: general physics and chemistry courses, and desire to work in experimental laboratory. This...

  8. Metastability and relaxation in tensile SiGe on Ge(001) virtual substrates

    SciTech Connect (OSTI)

    Frigerio, Jacopo; Lodari, Mario; Chrastina, Daniel, E-mail: daniel.chrastina@polimi.it; Mondiali, Valeria; Isella, Giovanni [L-NESS, Dipartimento di Fisica, Politecnico di Milano, Polo di Como, via Anzani 42, 22100 Como (Italy); Bollani, Monica [IFN-CNR, L-NESS, via Anzani 42, 22100 Como (Italy)

    2014-09-21

    We systematically study the heteroepitaxy of SiGe alloys on Ge virtual substrates in order to understand strain relaxation processes and maximize the tensile strain in the SiGe layer. The degree of relaxation is measured by high-resolution x-ray diffraction, and surface morphology is characterized by atomic force microscopy. The results are analyzed in terms of a numerical model, which considers dislocation nucleation, multiplication, thermally activated glide, and strain-dependent blocking. Relaxation is found to be sensitive to growth rate and substrate temperature as well as epilayer misfit and thickness, and growth parameters are found which allow a SiGe film with over 4 GPa of tensile stress to be obtained.

  9. GE partners with 'Girls Who Code' for summer program | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    offered 19 programs and counted 375 participants; this year, Girls Who Code will offer 60 programs reaching close to 1,200 girls in nine cities nationwide. GE joins other...

  10. Sensitivity of CTA to dark matter signals from the Galactic Center

    E-Print Network [OSTI]

    Mathias Pierre; Jennifer M. Siegal-Gaskins; Pat Scott

    2014-10-13

    (abridged) The Galactic Center is one of the most promising targets for indirect detection of dark matter with gamma rays. We investigate the sensitivity of the upcoming Cherenkov Telescope Array (CTA) to dark matter annihilation and decay in the Galactic Center. As the inner density profile of the Milky Way's dark matter halo is uncertain, we study the impact of the slope of the Galactic density profile, inwards of the Sun, on the prospects for detecting a dark matter signal with CTA. We find that the sensitivity achieved by CTA to annihilation signals is strongly dependent on the inner profile slope, whereas the dependence is more mild in the case of dark matter decay. Surprisingly, we find that the optimal choice of signal and background regions is virtually independent of the assumed density profile. For the fiducial case of a Navarro-Frenk-White profile, we find that CTA will be able to probe annihilation cross sections well below the canonical thermal relic value for dark matter masses from a few tens of GeV up to $\\sim 5$ TeV for annihilation to $\\tau^{+}\\tau^{-}$, and will achieve only a slightly weaker sensitivity for annihilation to $b\\bar{b}$ or $\\mu^{+}\\mu^{-}$. CTA will improve significantly on current sensitivity to annihilation signals for dark matter masses above $\\sim 100$ GeV, covering parameter space that is complementary to that probed by searches with the Fermi Large Area Telescope. The interpretation of apparent excesses in the measured cosmic-ray electron and positron spectra as signals of dark matter decay will also be testable with CTA observations of the Galactic Center. We demonstrate that both for annihilation and for decay, including spectral information for hard channels (such as $\\mu^{+}\\mu^{-}$ and $\\tau^{+}\\tau^{-}$) leads to enhanced sensitivity for dark matter masses above $m_{\\rm DM}\\sim 200$ GeV.

  11. Dark-matter harmonics beyond annual modulation

    SciTech Connect (OSTI)

    Lee, Samuel K.; Lisanti, Mariangela; Safdi, Benjamin R. E-mail: mlisanti@princeton.edu

    2013-11-01

    The count rate at dark-matter direct-detection experiments should modulate annually due to the motion of the Earth around the Sun. We show that higher-frequency modulations, including daily modulation, are also present and in some cases are nearly as strong as the annual modulation. These higher-order modes are particularly relevant if (i) the dark matter is light, O(10) GeV, (ii) the scattering is inelastic, or (iii) velocity substructure is present; for these cases, the higher-frequency modes are potentially observable at current and ton-scale detectors. We derive simple expressions for the harmonic modes as functions of the astrophysical and geophysical parameters describing the Earth's orbit, using an updated expression for the Earth's velocity that corrects a common error in the literature. For an isotropic halo velocity distribution, certain ratios of the modes are approximately constant as a function of nuclear recoil energy. Anisotropic distributions can also leave observable features in the harmonic spectrum. Consequently, the higher-order harmonic modes are a powerful tool for identifying a potential signal from interactions with the Galactic dark-matter halo.

  12. Energy Secretary Chu to Tour GE Global Research Advanced Manufacturing...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Secretary Chu to Tour GE Global Research Advanced Manufacturing Lab Energy Secretary Chu to Tour GE Global Research Advanced Manufacturing Lab May 24, 2012 - 10:54am Addthis...

  13. Butterfly-Inspired Thermal Imaging | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    GE Innovation and Manufacturing in Europe 2-4-13-v-3d-printing-medical-devices Additive Manufacturing Demonstration at GE Global Research 2-3-10-v Crowdsourcing...

  14. What Happens in Research-Based Design | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    paths we have at GE Global Research ("GE Leaders are Researchers Too",). The field of gas turbine heat transfer is growing in importance, and as a result, we have a lot of job...

  15. Cosmology with Mimetic Matter

    SciTech Connect (OSTI)

    Chamseddine, Ali H.; Mukhanov, Viatcheslav; Vikman, Alexander E-mail: viatcheslav.Mukhanov@lmu.de

    2014-06-01

    We consider minimal extensions of the recently proposed Mimetic Dark Matter and show that by introducing a potential for the mimetic non-dynamical scalar field we can mimic nearly any gravitational properties of the normal matter. In particular, the mimetic matter can provide us with inflaton, quintessence and even can lead to a bouncing nonsingular universe. We also investigate the behaviour of cosmological perturbations due to a mimetic matter. We demonstrate that simple mimetic inflation can produce red-tilted scalar perturbations which are largely enhanced over gravity waves.

  16. Energy Matters Mailbag

    Broader source: Energy.gov [DOE]

    This edition of the mailbag tackles follow-up questions from our Energy Matters discussion on breaking our reliance on foreign oil.

  17. Dipolar Dark Matter

    E-Print Network [OSTI]

    Luc Blanchet; Lavinia Heisenberg

    2015-05-19

    Massive gravity theories have been developed as viable IR modifications of gravity motivated by dark energy and the problem of the cosmological constant. On the other hand, modified gravity and modified dark matter theories were developed with the aim of solving the problems of standard cold dark matter at galactic scales. Here we propose to adapt the framework of ghost-free massive bigravity theories to reformulate the problem of dark matter at galactic scales. We investigate a promising alternative to dark matter called dipolar dark matter (DDM) in which two different species of dark matter are separately coupled to the two metrics of bigravity and are linked together by an internal vector field. We show that this model successfully reproduces the phenomenology of dark matter at galactic scales (i.e. MOND) as a result of a mechanism of gravitational polarisation. The model is safe in the gravitational sector, but because the two types of dark matter interact through the vector field, a ghostly degree of freedom in the decoupling limit is reintroduced in the dark matter sector. Crucial questions to address in future work is whether the polarisation mechanism can be realized in absence of ghosts, and what are the cosmological implications of the model.

  18. Probing the Small Scale Matter Power Spectrum through Dark Matter Annihilation in the Early Universe

    E-Print Network [OSTI]

    Aravind Natarajan; Nick Zhu; Naoki Yoshida

    2015-03-11

    Recent observations of the cosmic microwave background (CMB) anisotropies and the distribution of galaxies, galaxy clusters, and the Lyman Alpha forest have constrained the shape of the power spectrum of matter fluctuations on large scales k Energy released by dark matter annihilation can modify the spectrum of CMB temperature fluctuations and thus CMB experiments such as Planck have been able to constrain the quantity f /m energy absorbed by gas, is the annihilation rate assumed constant, and m is the particle mass. We assume the standard scale-invariant primordial matter power spectrum of P_prim(k) ~ k^{n_s} at large scales k n_s, the excess small-scale power results in a much larger number of nonlinear small mass halos, particularly at high redshifts. Dark matter annihilation in these halos releases sufficient energy to partially ionize the gas, and consequently modify the spectrum of CMB fluctuations. We show that the recent Planck data can already be used to constrain the power spectrum on small scales. For a simple model with an NFW profile with halo concentration parameter c_200 = 5 and f / m = 1/100 picobarn c / GeV, we can limit the mass variance sigma_{max} < 100 at the 95% confidence level, corresponding to a power law index m_s < 1.43 (1.63) for k_p = 100 (1000) h/Mpc. Our results are also relevant to theories that feature a running spectral index.

  19. Stable Higgs Bosons - new candidate for cold dark matter -

    E-Print Network [OSTI]

    Yutaka Hosotani

    2010-03-31

    The Higgs boson is in the backbone of the standard model of electroweak interactions. It must exist in some form for achieving unification of interactions. In the gauge-Higgs unification scenario the Higgs boson becomes a part of the extra-dimensional component of gauge fields. The Higgs boson becomes absolutely stable in a class of the gauge-Higgs unification models, serving as a promising candidate for cold dark matter in the universe. The observed relic abundance of cold dark matter is obtained with the Higgs mass around 70 GeV. The Higgs-nucleon scattering cross section is found to be close to the recent CDMS II and XENON10 bounds in the direct detection of dark matter. In collider experiments stable Higgs bosons are produced in a pair, appearing as missing energies and momenta so that the way of detecting Higgs bosons must be altered.

  20. Isospin-Violating Dark Matter and Neutrinos From the Sun

    E-Print Network [OSTI]

    Shao-Long Chen; Yue Zhang

    2011-06-20

    We study the indirect detection of dark matter through neutrino flux from their annihilation in the center of the Sun, in a class of theories where the dark matter-nucleon spin-independent interactions break the isospin symmetry. We point out that, while the direct detection bounds with heavy targets like Xenon are weakened and reconciled with the positive signals in DAMA and CoGeNT experiments, the indirect detection using neutrino telescopes can impose a relatively stronger constraint and brings tension to such explanation, if the annihilation is dominated by heavy quark or $\\tau$-lepton final states. As a consequence, the qualified isospin violating dark matter candidate has to preferably annihilate into light flavors.

  1. The Past and Future of Light Dark Matter Direct Detection

    E-Print Network [OSTI]

    Jonathan H. Davis

    2015-06-12

    We review the status and future of direct searches for light dark matter. We start by answering the question: `Whatever happened to the light dark matter anomalies?' i.e. the fate of the potential dark matter signals observed by the CoGeNT, CRESST-II, CDMS-Si and DAMA/LIBRA experiments. We discuss how the excess events in the first two of these experiments have been explained by previously underestimated backgrounds. For DAMA we summarise the progress and future of mundane explanations for the annual modulation reported in its event rate. Concerning the future of direct detection we focus on the irreducible background from solar neutrinos. We explain broadly how it will affect future searches and summarise efforts to mitigate its effects.

  2. Similarity of Stranski-Krastanow growth of Ge/Si and SiGe/Si (001)

    SciTech Connect (OSTI)

    Norris, D. J.; Qiu, Y.; Walther, T. [Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Dobbie, A.; Myronov, M. [Department of Physics, University of Warwick, Coventry CV4 7A (United Kingdom)

    2014-01-07

    This study investigates the onset of islanding (Stranski-Krastanow transition) in strained pure germanium (Ge) and dilute silicon-germanium (SiGe) alloy layers grown by chemical vapour deposition on Si(001) substrates. Integration of compositional profiles is compared to a novel method for quantification of X-ray maps acquired in cross-sectional scanning transmission electron microscopy, together with simulations of surface segregation of Ge. We show that Si{sub 1?x}Ge{sub x} alloys for germanium concentrations x???0.27 grow two-dimensionally and stay flat up to considerable layer thicknesses, while layers with concentrations in the range 0.28?Ge is ±(0.2–0.3) ML. Modelling shows that of the amount of germanium deposited, 0.7 ML segregate towards the free surface so that only ?2.3/x ML are directly incorporated in the layer within a few nanometres, in good agreement with our measurements. For pure Ge (x?=?1), this thickness is smaller than most values quoted in the literature, which we attribute to the high sensitivity of our method to fractional monolayer changes in the effective chemical width of such thin layers.

  3. Strain and stability of ultrathin Ge layers in Si/Ge/Si axial heterojunction nanowires

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ross, Frances M.; Stach, Eric A.; Wen, Cheng -Yen; Reuter, Mark C.; Su, Dong

    2015-02-05

    The abrupt heterointerfaces in the Si/Ge materials system presents useful possibilities for electronic device engineering because the band structure can be affected by strain induced by the lattice mismatch. In planar layers, heterointerfaces with abrupt composition changes are difficult to realize without introducing misfit dislocations. However, in catalytically grown nanowires, abrupt heterointerfaces can be fabricated by appropriate choice of the catalyst. Here we grow nanowires containing Si/Ge and Si/Ge/Si structures respectively with sub-1nm thick Ge "quantum wells" and we measure the interfacial strain fields using geometric phase analysis. Narrow Ge layers show radial strains of several percent, with a correspondingmore »dilation in the axial direction. Si/Ge interfaces show lattice rotation and curvature of the lattice planes. We conclude that high strains can be achieved, compared to what is possible in planar layers. In addition, we study the stability of these heterostructures under heating and electron beam irradiation. The strain and composition gradients are supposed to the cause of the instability for interdiffusion.« less

  4. Thin SiGe virtual substrates for Ge heterostructures integration on silicon

    SciTech Connect (OSTI)

    Cecchi, S., E-mail: stefano.cecchi@mdm.imm.cnr.it; Chrastina, D.; Frigerio, J.; Isella, G. [L-NESS, Dipartimento di Fisica, Politecnico di Milano–Polo Territoriale di Como, Via Anzani 42, I-22100 Como (Italy); Gatti, E.; Guzzi, M. [L-NESS, Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, via Cozzi 53, I-20126 Milano (Italy); Müller Gubler, E. [Electron Microscopy ETH Zurich, ETH Zurich, Auguste-Piccard-Hof 1, CH-8093 Zurich (Switzerland); Paul, D. J. [School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LT (United Kingdom)

    2014-03-07

    The possibility to reduce the thickness of the SiGe virtual substrate, required for the integration of Ge heterostructures on Si, without heavily affecting the crystal quality is becoming fundamental in several applications. In this work, we present 1??m thick Si{sub 1?x}Ge{sub x} buffers (with x?>?0.7) having different designs which could be suitable for applications requiring a thin virtual substrate. The rationale is to reduce the lattice mismatch at the interface with the Si substrate by introducing composition steps and/or partial grading. The relatively low growth temperature (475?°C) makes this approach appealing for complementary metal-oxide-semiconductor integration. For all the investigated designs, a reduction of the threading dislocation density compared to constant composition Si{sub 1?x}Ge{sub x} layers was observed. The best buffer in terms of defects reduction was used as a virtual substrate for the deposition of a Ge/SiGe multiple quantum well structure. Room temperature optical absorption and photoluminescence analysis performed on nominally identical quantum wells grown on both a thick graded virtual substrate and the selected thin buffer demonstrates a comparable optical quality, confirming the effectiveness of the proposed approach.

  5. Monolithic Ge/Si Avalanche Photodiodes Yimin Kanga*

    E-Print Network [OSTI]

    Bowers, John

    Monolithic Ge/Si Avalanche Photodiodes Yimin Kanga* , Mike Morsea , Mario J. Panicciaa , Moshe, Charlottesville, VA 22904, USA Abstract: We demonstrate mesa-type and waveguide-type Ge/Si avalanche photodiodes. Research on the Ge/Si photodiodes, one of the fundamental components needed for building integrated silicon

  6. MOTION OF ELECTRON-HOLE DROPS IN Ge

    E-Print Network [OSTI]

    Westervelt, R.M.

    2011-01-01

    MOTION OF ELECTRON-HOLE DROPS IN Ge R. M. Westervelt, J. C.MOTION OF ELECTRON-HOLE DROPS IN Ge R. M. Westervelt, J. C.OF ELECTRON-HOLE DROPS IN Ge R M Westervelt, J C Culbertson

  7. Conduction band discontinuity and electron confinement at the Si[subscript x]Ge[subscript 1?x]/Ge interface

    E-Print Network [OSTI]

    Mazzeo, G.

    Germanium rich heterostructures can constitute a valid alternative to Silicon for the confinement of single electron spins. The conduction band discontinuity in SiGe/Ge heterostructures grown on pure germanium substrate ...

  8. Stealth Dark Matter: Dark scalar baryons through the Higgs portal

    E-Print Network [OSTI]

    Thomas Appelquist; Richard C. Brower; Michael I. Buchoff; George T. Fleming; Xiao-Yong Jin; Joe Kiskis; Graham D. Kribs; Ethan T. Neil; James C. Osborn; Claudio Rebbi; Enrico Rinaldi; David Schaich; Chris Schroeder; Sergey Syritsyn; Pavlos Vranas; Evan Weinberg; Oliver Witzel

    2015-05-28

    We present a new model of "Stealth Dark Matter": a composite baryonic scalar of an $SU(N_D)$ strongly-coupled theory with even $N_D \\geq 4$. All mass scales are technically natural, and dark matter stability is automatic without imposing an additional discrete or global symmetry. Constituent fermions transform in vector-like representations of the electroweak group that permit both electroweak-breaking and electroweak-preserving mass terms. This gives a tunable coupling of stealth dark matter to the Higgs boson independent of the dark matter mass itself. We specialize to $SU(4)$, and investigate the constraints on the model from dark meson decay, electroweak precision measurements, basic collider limits, and spin-independent direct detection scattering through Higgs exchange. We exploit our earlier lattice simulations that determined the composite spectrum as well as the effective Higgs coupling of stealth dark matter in order to place bounds from direct detection, excluding constituent fermions with dominantly electroweak-breaking masses. A lower bound on the dark baryon mass $m_B \\gtrsim 300$ GeV is obtained from the indirect requirement that the lightest dark meson not be observable at LEP II. We briefly survey some intriguing properties of stealth dark matter that are worthy of future study, including: collider studies of dark meson production and decay; indirect detection signals from annihilation; relic abundance estimates for both symmetric and asymmetric mechanisms; and direct detection through electromagnetic polarizability, a detailed study of which will appear in a companion paper.

  9. Energy and matter

    E-Print Network [OSTI]

    Gobato, Ricardo; Fedrigo, Desire Francine Gobato

    2015-01-01

    Our work is an approach between matter and energy. Using the famous equation E = mc^2, Einstein and the Law of Universal Gravitation of Newton, we estimate that a small amount matter converted into energy is needed to lift, using the gravitational potential energy equation on the surface, a mountain of solid iron or even Mount Everest.

  10. Dark matter searches

    E-Print Network [OSTI]

    Baudis, Laura

    2015-01-01

    One of the major challenges of modern physics is to decipher the nature of dark matter. Astrophysical observations provide ample evidence for the existence of an invisible and dominant mass component in the observable universe, from the scales of galaxies up to the largest cosmological scales. The dark matter could be made of new, yet undiscovered elementary particles, with allowed masses and interaction strengths with normal matter spanning an enormous range. Axions, produced non-thermally in the early universe, and weakly interacting massive particles (WIMPs), which froze out of thermal equilibrium with a relic density matching the observations, represent two well-motivated, generic classes of dark matter candidates. Dark matter axions could be detected by exploiting their predicted coupling to two photons, where the highest sensitivity is reached by experiments using a microwave cavity permeated by a strong magnetic field. WIMPs could be directly observed via scatters off atomic nuclei in underground, ultr...

  11. Dark matter axions

    E-Print Network [OSTI]

    P. Sikivie

    2009-09-04

    The hypothesis of an `invisible' axion was made by Misha Shifman and others, approximately thirty years ago. It has turned out to be an unusually fruitful idea, crossing boundaries between particle physics, astrophysics and cosmology. An axion with mass of order $10^{-5}$ eV (with large uncertainties) is one of the leading candidates for the dark matter of the universe. It was found recently that dark matter axions thermalize and form a Bose-Einstein condensate (BEC). Because they form a BEC, axions differ from ordinary cold dark matter (CDM) in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles. Because there is evidence for these phenomena, unexplained with ordinary CDM, an argument can be made that the dark matter is axions.

  12. Dissipation of dark matter

    E-Print Network [OSTI]

    Hermano Velten; Dominik J. Schwarz

    2012-10-01

    Fluids often display dissipative properties. We explore dissipation in the form of bulk viscosity in the cold dark matter fluid. We constrain this model using current data from supernovae, baryon acoustic oscillations and the cosmic microwave background. Considering the isotropic and homogeneous background only, viscous dark matter is allowed to have a bulk viscosity $\\lesssim 10^7$ Pa$\\cdot$s, also consistent with the expected integrated Sachs-Wolfe effect (which plagues some models with bulk viscosity). We further investigate the small-scale formation of viscous dark matter halos, which turns out to place significantly stronger constraints on the dark matter viscosity. The existence of dwarf galaxies is guaranteed only for much smaller values of the dark matter viscosity, $\\lesssim 10^{-3}$ Pa$\\cdot$s.

  13. Testing Higgs portal dark matter via $Z$ fusion at a linear collider

    E-Print Network [OSTI]

    Shinya Kanemura; Shigeki Matsumoto; Takehiro Nabeshima; Hiroyuki Taniguchi

    2011-02-25

    We investigate the possibility of detecting dark matter at TeV scale linear colliders in the scenario where the dark matter is a massive particle weakly interacting only with the Higgs boson $h$ in the low energy effective theory (the Higgs portal dark matter scenario). The dark matter in this scenario would be difficult to be tested at the CERN Large Hadron Collider when the decay of the Higgs boson into a dark matter pair is not kinematically allowed. We study whether even in such a case the dark matter $D$ can be explored or not via the $Z$ boson fusion process at the International Linear Collider and also at a multi TeV lepton collider. It is found that for the collision energy $\\sqrt{S}>1$ TeV with the integrated luminosity 1 ab$^{-1}$, the signal ($e^{\\pm}e^-\\to e^{\\pm}e^-h^\\ast \\to e^{\\pm}e^-DD$) can be seen after appropriate kinematic cuts. In particular, when the dark matter is a fermion or a vector, which is supposed to be singlet under the standard gauge symmetry, the signal with the mass up to 100 GeV can be tested for the Higgs boson mass to be 120 GeV.

  14. Properties of excited states in {sup 77}Ge.

    SciTech Connect (OSTI)

    Kay, B. P.; Chiara, C. J.; Schiffer, J. P.; Kondev, F. G.; Zhu, S.; Carpenter, M. P.; Janssens, R. V. F.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Seweryniak, D.; Stefanescu, I.; Univ. of Maryland; Horia-Hulubei National Inst. for Physics and Nuclear Engineering

    2009-07-01

    The nucleus {sup 77}Ge was studied through the {sup 76}Ge({sup 13}C,{sup 12}C){sup 77}Ge reaction at a sub-Coulomb energy. The angular distributions of rays depopulating excited states in {sup 77}Ge were measured in order to constrain spin and parity assignments. Some of these assignments are of use in connection with neutrinoless double beta decay, where the population of states near the Fermi surface of {sup 76}Ge was recently explored using transfer reactions.

  15. Particle Production at 3 GeV X. Ding, UCLA

    E-Print Network [OSTI]

    McDonald, Kirk

    = 50m 0.02976 (neg: 0.01206, pos: 0.01770) Carbon 3 GeV, Z = 0m 0.03341 (neg: 0.01370, pos: 0.01971) Mercury 3 GeV, Z = 50 m 0.02096 (neg: 0.01070, pos: 0.01026) Mercury 3 GeV, Z = 0 m 0.02496 (neg: 0.01273, pos: 0.01223) Mercury 8 GeV, Z = 50 m 0.0263 (neg: 0.0136, pos: 0.0127) Mercury 8 GeV, Z = 0m 0

  16. Dark Matter and the Baryon Asymmetry

    E-Print Network [OSTI]

    Glennys R. Farrar; Gabrijela Zaharijas

    2005-10-06

    We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\\sigma^{\\rm annih}_{\\bar{X}} < \\sigma^{\\rm annih}_{X} $, the $\\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If $m_X \\lsi 4.5 B_X $GeV and the annihilation cross sections differ by $\\mathcal{O}$(10%) or more, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$. Two concrete examples are given, one of which can be excluded on observational grounds.

  17. Role of nucleation sites on the formation of nanoporous Ge

    SciTech Connect (OSTI)

    Yates, B. R.; Darby, B. L.; Jones, K. S. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611-6400 (United States); Elliman, R. G. [Department of Electronic Materials Engineering, Research School of Physical Sciences and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)

    2012-09-24

    The role of nucleation sites on the formation of nanoporous Ge was investigated. Three Ge films with different spherical or columnar pore morphologies to act as inherent nucleation sites were sputtered on (001) Ge. Samples were implanted 90 Degree-Sign from incidence at 300 keV with fluences ranging from 3.0 Multiplication-Sign 10{sup 15} to 3.0 Multiplication-Sign 10{sup 16} Ge{sup +}/cm{sup 2}. Electron microscopy investigations revealed varying thresholds for nanoporous Ge formation and exhibited a stark difference in the evolution of the Ge layers based on the microstructure of the initial film. The results suggest that the presence of inherent nucleation sites significantly alters the onset and evolution of nanoporous Ge.

  18. Monolayer Passivation of Ge(100) Surface via Nitridation and Oxidation Joon Sung Leea,b

    E-Print Network [OSTI]

    Kummel, Andrew C.

    Monolayer Passivation of Ge(100) Surface via Nitridation and Oxidation Joon Sung Leea,b , Sarah R passivation of Ge(100) surface via formation of Ge-N and Ge-O surface species was studied using scanning cyclotron resonance (ECR) plasma source formed an ordered Ge-N structure on a Ge(100) surface at 500o C. DFT

  19. Prompt Gamma Rays in {sup 77}Ge after Neutron Capture on {sup 76}Ge

    SciTech Connect (OSTI)

    Meierhofer, Georg; Grabmayr, Peter; Jochum, Josef [Physikalisches Institut, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 14, 72076 Tuebingen (Germany); Canella, Lea [Institut fuer Radiochemie, Technische Universitaet Muenchen, Walther-Meissner-Str. 3, 85748 Garching (Germany); Jolie, Jan; Kudejova, Petra; Warr, Nigel [Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Cologne (Germany)

    2009-01-28

    The observation of neutrinoless double beta decay would be proof of the Majorana nature of the neutrino. Half-lives for these decays are very long (for {sup 76}Ge:>10{sup 25} y), so background reduction and rejection is the major task for double beta experiments. The GERDA (GERmanium Detector Array) experiment at the Gran Sasso Laboratory of the INFN (LNGS) searches for neutrinoless double beta decay of {sup 76}Ge. The isotope {sup 76}Ge is an ideal candidate because it can be used as source and detector at the same time. A large remaining contribution to the background arises from the prompt gamma cascade after neutron capture by {sup 76}Ge followed by {beta}{sup -}-decay of {sup 77}Ge. Since the prompt gamma decay scheme is poorly known, measurements with isotopically enriched Germanium samples were carried out at the PGAA facility at the research reactor FRM II (Munich). With the known prompt gamma spectrum it will be possible to improve the overall veto efficiency of the GERDA experiment.

  20. Relativistic Laser-Matter Interactions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Relativistic Laser-Matter Interactions Relativistic Laser-Matter Interactions Enabling the next generation of intense particle accelerators Contact Juan Fernandez (505) 667-6575...

  1. Material properties in SiGe/Ge quantum wells Rebecca K. Schaevitz*, Jonathan E. Roth, Onur Fidaner, and David A. B. Miller

    E-Print Network [OSTI]

    Miller, David A. B.

    Material properties in SiGe/Ge quantum wells Rebecca K. Schaevitz*, Jonathan E. Roth, Onur Fidaner *Corresponding author: rschaevitz@stanford.edu Abstract: Photocurrent measurements in Ge quantum wells parameters for design of high-performance SiGe/Ge quantum well optoelectronics on silicon. Germanium

  2. Ge/SiGe Quantum Confined Stark Effect Modulators on Silicon James S. Harris, Yu-Hsuan Kuo, and David A. B. Miller

    E-Print Network [OSTI]

    Miller, David A. B.

    Ge/SiGe Quantum Confined Stark Effect Modulators on Silicon James S. Harris, Yu-Hsuan Kuo bandwidth have been demonstrated [4]. 2. Quantum well design Ge is an indirect band gap material, but it has. In order to have good quantum confinement, SiGe barriers are used since Si and Ge have a very high direct

  3. Study of Centrality Dependence of Transverse Momentum Spectra of Hadrons and the Freeze-out Parameters at root(sNN) of 62.4 GeV, 130 GeV and 200 GeV

    E-Print Network [OSTI]

    Saeed Uddin; Riyaz Ahmed Bhat; Inam-ul Bashir

    2014-12-05

    We attempt to describe the rapidity distribution of P, P-bar, K+ and K- for the most central Au+Au collisions at root(sNN) of 62.4 GeV,130 GeV and 200 GeV. The transverse momentum spectra of strange as well as non-strange hadrons e.g. P, P-bar, K+, K-, Lambda, Lambda-bar, Cascade,Cascade-bar and (Omega + Omega-bar) are studied for the whole centrality classes at all the three RHIC energies. The experimental data of the transverse momentum spectra and the rapidity distributions are well reproduced. This is done by using a statistical thermal freeze-out model which incorporates the rapidity (collision) axis as well as transverse direction boosts developed within an expanding hot and dense hadronic fluid (fireball) till the final freeze-out. We determine the thermo-chemical freeze-out conditions particularly in terms of temperature, baryon chemical potential and collective flow effect parameters for different particle species. The parameters indicate occurrence of freeze-out of the singly and doubly strange hyperon species at somewhat earlier times during the evolution of the fireball. Dependence of the freeze-out parameters on the degree of centrality is also described and it is found that the kinetic temperature increases and collective flow effect decreases with decreasing centrality at all energies studied. The nuclear transparency effect is also studied and it is clear from our model that the nuclear matter becomes more transparent at the highest RHIC energy compared to lower RHIC energies. The contribution of heavier hadronic resonance decay is taken into account.

  4. Pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV: Evidence for the onset of deconfinement

    E-Print Network [OSTI]

    NA49 Collaboration

    2007-10-15

    Results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies. A rapid change of the energy dependence is observed around 30A GeV for the yields of pions and kaons as well as for the shape of the transverse mass spectra. The change is compatible with the prediction that the threshold for production of a state of deconfined matter at the early stage of the collisions is located at low SPS energies.

  5. Axion BEC Dark Matter

    E-Print Network [OSTI]

    Erken, Ozgur; Tam, Heywood; Yang, Qiaoli

    2011-01-01

    Cold dark matter axions thermalize through gravitational self-interactions and form a Bose-Einstein condensate when the photon temperature reaches approximately 500 eV. Axion Bose-Einstein condensation provides an opportunity to distinguish axions from the other dark matter candidates on the basis of observation. The rethermalization of axions that are about to fall in a galactic potential well causes them to acquire net overall rotation, whereas ordinary cold dark matter falls in with an irrotational velocity field. The inner caustics of galactic halos are different in the two cases.

  6. Axion BEC Dark Matter

    E-Print Network [OSTI]

    Ozgur Erken; Pierre Sikivie; Heywood Tam; Qiaoli Yang

    2011-11-16

    Cold dark matter axions thermalize through gravitational self-interactions and form a Bose-Einstein condensate when the photon temperature reaches approximately 500 eV. Axion Bose-Einstein condensation provides an opportunity to distinguish axions from the other dark matter candidates on the basis of observation. The rethermalization of axions that are about to fall in a galactic potential well causes them to acquire net overall rotation, whereas ordinary cold dark matter falls in with an irrotational velocity field. The inner caustics of galactic halos are different in the two cases.

  7. Dark Matter 2014

    E-Print Network [OSTI]

    Marc Schumann

    2015-01-06

    This article gives an overview on the status of experimental searches for dark matter at the end of 2014. The main focus is on direct searches for weakly interacting massive particles (WIMPs) using underground-based low-background detectors, especially on the new results published in 2014. WIMPs are excellent dark matter candidates, predicted by many theories beyond the standard model of particle physics, and are expected to interact with the target nuclei either via spin-independent (scalar) or spin-dependent (axial-vector) couplings. Non-WIMP dark matter candidates, especially axions and axion-like particles are also briefly discussed.

  8. Effective Models for Dark Matter at the International Linear Collider

    E-Print Network [OSTI]

    Daniel Schmeier

    2013-08-20

    Weakly interacting massive particles (WIMPs) form a promising solution to the dark matter problem and many experiments are now searching for these particles. Using effective field theories to describe the interaction of the WIMP with the Standard Model has proven successful in providing an easy way to compare the different experimental results. In this work, we show how effective operators can be formally derived from a UV-complete underlying theory, and we analyse these operators in different experimental contexts. We put our main focus on the expected sensitivity of the International Linear Collider (ILC) in searching for WIMPs by looking at events with single photons in the final state. Furthermore, we show explicit evaluations of the relic density measurements from the Wilkinson Microwave Anisotropy Probe and the XENON Dark Matter Project direct detection measurements to compare to the expected ILC results. We find that the ILC serves as a unique tool to probe possible WIMP interactions with the Standard Model for dark matter masses below 10 GeV. This extends to masses up to 490 GeV in cases where the interaction is spin-dependent or leptophilic.

  9. Maximum Likelihood Signal Extraction Method Applied to 3.4 years of CoGeNT Data

    E-Print Network [OSTI]

    C. E. Aalseth; P. S. Barbeau; J. Diaz Leon; J. E. Fast; T. W. Hossbach; A. Knecht; M. S. Kos; M. G. Marino; H. S. Miley; M. L. Miller; J. L. Orrell

    2015-02-05

    CoGeNT has taken data for over 3 years, with 1136 live days of data accumulated as of April 23, 2013. We report on the results of a maximum likelihood analysis to extract any possible dark matter signal present in the collected data. The maximum likelihood signal extraction uses 2-dimensional probability density functions (PDFs) to characterize the anticipated variations in dark matter interaction rates for given observable nuclear recoil energies during differing periods of the Earth's annual orbit around the Sun. Cosmogenic and primordial radioactivity backgrounds are characterized by their energy signatures and in some cases decay half-lives. A third parameterizing variable -- pulse rise-time -- is added to the likelihood analysis to characterize slow rising pulses described in prior analyses. The contribution to each event category is analyzed for various dark matter signal hypotheses including a dark matter standard halo model and a case with free oscillation parameters (i.e., amplitude, period, and phase). The best-fit dark matter signal is in close proximity to previously reported results. We find that the significance of the extracted dark matter signal remains well below evidentiary at 1.7 $\\sigma$.

  10. Matter & Energy Civil Engineering

    E-Print Network [OSTI]

    Rogers, John A.

    See Also: Matter & Energy Detectors· Optics· Civil Engineering· Engineering· Nature of Water Yonggang Huang, Joseph Cummings Professor of Civil and Environmental Engineering and Mechanical Engineering· Electronics· Reference Photography· Infrared· Mechanical engineering · Optics· ScienceDaily (Jan. 17, 2011

  11. Gaseous dark matter detectors

    E-Print Network [OSTI]

    Martoff, C. J.

    Dark matter (DM) detectors with directional sensitivity have the potential of yielding an unambiguous positive observation of WIMPs as well as discriminating between galactic DM halo models. In this paper, we introduce the ...

  12. Matter & Energy Electronics

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    See also: Matter & Energy Detectors· Electronics· Technology· Medical Technology· Weapons Technology · Organic Chemistry· Reference Hydrogen chloride· Photography· Catalytic converter· Nanomedicine a series of tiny colored dots ­ each a different pigment ­ on an inert backing such as paper, plastic

  13. The Heart of Matter

    E-Print Network [OSTI]

    Rohini M. Godbole

    2010-06-30

    In this article I trace the development of the human understanding of the "Heart of Matter" from early concepts of "elements" (or alternatively "Panchmahabhootas") to the current status of "quarks" and "leptons" as the fundamental constituents of matter, interacting together via exchange of the various force carrier particles called "gauge bosons" such as the photon, W/Z-boson etc. I would like to show how our understanding of the fundamental constituents of matter has gone hand in hand with our understanding of the fundamental forces in nature. I will also outline how the knowledge of particle physics at the "micro" scale of less than a Fermi(one millionth of a nanometer), enables us to offer explanations of Cosmological observations at the "macro" scale. Consequently these observations, may in turn, help us address some very fundamental questions of the Physics at the "Heart of the Matter".

  14. Hot and dark matter

    E-Print Network [OSTI]

    D'Eramo, Francesco

    2012-01-01

    In this thesis, we build new Effective Field Theory tools to describe the propagation of energetic partons in hot and dense media, and we propose two new reactions for dark matter in the early universe. In the first part, ...

  15. Interface and nanostructure evolution of cobalt germanides on Ge(001)

    SciTech Connect (OSTI)

    Grzela, T., E-mail: grzela@ihp-microelectronics.com; Schubert, M. A. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Koczorowski, W. [London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WC1H 0AH,United Kingdom (United Kingdom); Institute of Physics, Poznan University of Technology, Nieszawska 13A, 60-965 Poznan (Poland); Capellini, G. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Dipartimento di Scienze, Università degli Studi Roma Tre, I-00146 Roma (Italy); Czajka, R. [Institute of Physics, Poznan University of Technology, Nieszawska 13A, 60-965 Poznan (Poland); Radny, M. W. [Institute of Physics, Poznan University of Technology, Nieszawska 13A, 60-965 Poznan (Poland); School of Mathematical and Physical Sciences, The University of Newcastle, University Drive, Callaghan NSW, 2308 (Australia); Curson, N.; Schofield, S. R. [London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WC1H 0AH,United Kingdom (United Kingdom); Schroeder, T. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); BTU Cottbus, Konrad-Zuse Str. 1, 03046 Cottbus (Germany)

    2014-02-21

    Cobalt germanide (Co{sub x}Ge{sub y}) is a candidate system for low resistance contact modules in future Ge devices in Si-based micro and nanoelectronics. In this paper, we present a detailed structural, morphological, and compositional study on Co{sub x}Ge{sub y} formation on Ge(001) at room temperature metal deposition and subsequent annealing. Scanning tunneling microscopy and low energy electron diffraction clearly demonstrate that room temperature deposition of approximately four monolayers of Co on Ge(001) results in the Volmer Weber growth mode, while subsequent thermal annealing leads to the formation of a Co-germanide continuous wetting layer which evolves gradually towards the growth of elongated Co{sub x}Ge{sub y} nanostructures. Two types of Co{sub x}Ge{sub y} nanostructures, namely, flattop- and ridge-type, were observed and a systematic study on their evolution as a function of temperature is presented. Additional transmission electron microscopy and x-ray photoemission spectroscopy measurements allowed us to monitor the reaction between Co and Ge in the formation process of the Co{sub x}Ge{sub y} continuous wetting layer as well as the Co{sub x}Ge{sub y} nanostructures.

  16. The dark matter self-interaction and its impact on the critical mass for dark matter evaporations inside the sun

    E-Print Network [OSTI]

    Chian-Shu Chen; Fei-Fan Lee; Guey-Lin Lin; Yen-Hsun Lin

    2014-12-21

    We study the capture, annihilation and evaporation of dark matter (DM) inside the Sun. It has been shown that the DM self-interaction can increase the DM number inside the Sun. We demonstrate that this enhancement becomes more significant in the regime of small DM mass, given a fixed DM self-interaction cross section. This leads to the enhancement of neutrino flux from DM annihilation. On the other hand, for DM mass as low as as a few GeVs, not only the DM-nuclei scatterings can cause the DM evaporation, DM self-interaction also provides non-negligible contributions to this effect. Consequently, the critical mass for DM evaporation (typically 3 ~ 4 GeV without the DM self-interaction) can be slightly increased. We discuss the prospect of detecting DM self-interaction in IceCube- PINGU using the annihilation channels $\\chi\\chi\\rightarrow\

  17. Dark matter searches

    E-Print Network [OSTI]

    Laura Baudis

    2015-09-02

    One of the major challenges of modern physics is to decipher the nature of dark matter. Astrophysical observations provide ample evidence for the existence of an invisible and dominant mass component in the observable universe, from the scales of galaxies up to the largest cosmological scales. The dark matter could be made of new, yet undiscovered elementary particles, with allowed masses and interaction strengths with normal matter spanning an enormous range. Axions, produced non-thermally in the early universe, and weakly interacting massive particles (WIMPs), which froze out of thermal equilibrium with a relic density matching the observations, represent two well-motivated, generic classes of dark matter candidates. Dark matter axions could be detected by exploiting their predicted coupling to two photons, where the highest sensitivity is reached by experiments using a microwave cavity permeated by a strong magnetic field. WIMPs could be directly observed via scatters off atomic nuclei in underground, ultra low-background detectors, or indirectly, via secondary radiation produced when they pair annihilate. They could also be generated at particle colliders such as the LHC, where associated particles produced in the same process are to be detected. After a brief motivation and an introduction to the phenomenology of particle dark matter detection, I will discuss the most promising experimental techniques to search for axions and WIMPs, addressing their current and future science reach, as well as their complementarity.

  18. Colon Cancer Mapping | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D BGene NetworkNuclearDNP 20082 P2014 CollegiateVanderbilt, GE Team

  19. Crowdsourcing Software Announcement | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent Bonding in Actinide SandwichCrayCrosscuttingGE, MIT Build

  20. Crowdsourcing Software Award | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent Bonding in Actinide SandwichCrayCrosscuttingGE, MIT

  1. Patent Record Announcement | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass mapSpeeding access| Department ofStephenSkinner,Past and Present EERE Budget PastGE's

  2. Game Changing Technology | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFESOpportunities Nuclear PhysicsGE GlobalGetting&Tools »GambitI

  3. A Large Scale Double Beta and Dark Matter Experiment: GENIUS

    E-Print Network [OSTI]

    J. Hellmig; H. V. Klapdor-Kleingrothaus

    1998-01-21

    The recent results from the HEIDELBERG-MOSCOW experiment have demonstrated the large potential of double beta decay to search for new physics beyond the Standard Model. To increase by a major step the present sensitivity for double beta decay and dark matter search much bigger source strengths and much lower backgrounds are needed than used in experiments under operation at present or under construction. We present here a study of a project proposed recently, which would operate one ton of 'naked' enriched GErmanium-detectors in liquid NItrogen as shielding in an Underground Setup (GENIUS). It improves the sensitivity to neutrino masses to 0.01 eV. A ten ton version would probe neutrino masses even down to 10^-3 eV. The first version would allow to test the atmospheric neutrino problem, the second at least part of the solar neutrino problem. Both versions would allow in addition significant contributions to testing several classes of GUT models. These are especially tests of R-parity breaking supersymmetry models, leptoquark masses and mechanism and right-handed W-boson masses comparable to LHC. The second issue of the experiment is the search for dark matter in the universe. The entire MSSM parameter space for prediction of neutralinos as dark matter particles could be covered already in a first step of the full experiment - with the same purity requirements but using only 100 kg of 76Ge or even of natural Ge - making the experiment competitive to LHC in the search for supersymmetry. The layout of the proposed experiment is discussed and the shielding and purity requirements are studied using GEANT Monte Carlo simulations. As a demonstration of the feasibility of the experiment first results of operating a 'naked' Ge detector in liquid nitrogen are presented.

  4. Dark Matter Searches for Monoenergetic Neutrinos Arising from Stopped Meson Decay in the Sun

    E-Print Network [OSTI]

    Carsten Rott; Seongjin In; Jason Kumar; David Yaylali

    2015-10-01

    Dark matter can be gravitationally captured by the Sun after scattering off solar nuclei. Annihilations of the dark matter trapped and accumulated in the centre of the Sun could result in one of the most detectable and recognizable signals for dark matter. Searches for high-energy neutrinos produced in the decay of annihilation products have yielded extremely competitive constraints on the spin-dependent scattering cross sections of dark matter with nuclei. Recently, the low energy neutrino signal arising from dark-matter annihilation to quarks which then hadronize and shower has been suggested as a competitive and complementary search strategy. These high-multiplicity hadronic showers give rise to a large amount of pions which will come to rest in the Sun and decay, leading to a unique sub-GeV neutrino signal. We here improve on previous works by considering the monoenergetic neutrino signal arising from both pion and kaon decay. We consider searches at liquid scintillation, liquid argon, and water Cherenkov detectors and find very competitive sensitivities for few-GeV dark matter masses.

  5. Study of the low-lying states of Ge2 and Ge2 using negative ion zero electron kinetic energy spectroscopy

    E-Print Network [OSTI]

    Neumark, Daniel M.

    Study of the low-lying states of Ge2 and Ge2 using negative ion zero electron kinetic energy The low-lying states of Ge2 and Ge2 are probed using negative ion zero electron kinetic energy ZEKE spectroscopy. The ZEKE spectrum of Ge2 yields an electron affinity of 2.035 0.001 eV for Ge2, as well as term

  6. CHARACTERIZATION OF THE NEARBY L/T BINARY BROWN DWARF WISE J104915.57-531906.1 AT 2 pc FROM THE SUN

    SciTech Connect (OSTI)

    Kniazev, A. Y.; Vaisanen, P.; Potter, S. B.; Crawford, S.; Gulbis, A. A. S.; Muzic, K.; Mehner, A.; Boffin, H. M. J.; Melo, C.; Ivanov, V. D.; Girard, J.; Mawet, D.; Schmidtobreick, L.; Kurtev, R.; Borissova, J.; Huelamo, N.; Minniti, D.; Ishibashi, K.; Beletsky, Y.; Buckley, D. A. H.; and others

    2013-06-20

    WISE J104915.57-531906.1 is a L/T brown dwarf binary located 2 pc from the Sun. The pair contains the closest known brown dwarfs and is the third closest known system, stellar or sub-stellar. We report comprehensive follow-up observations of this newly uncovered system. We have determined the spectral types of both components (L8 {+-} 1, for the primary, agreeing with the discovery paper; T1.5 {+-} 2 for the secondary, which was lacking spectroscopic type determination in the discovery paper) and, for the first time, their radial velocities (V{sub rad} {approx} 23.1, 19.5 km s{sup -1}) using optical spectra obtained at the Southern African Large Telescope and other facilities located at the South African Astronomical Observatory (SAAO). The relative radial velocity of the two components is smaller than the range of orbital velocities for theoretically predicted masses, implying that they form a gravitationally bound system. We report resolved near-infrared JHK{sub S} photometry from the Infrared Survey Facility telescope at the SAAO which yields colors consistent with the spectroscopically derived spectral types. The available kinematic and photometric information excludes the possibility that the object belongs to any of the known nearby young moving groups or associations. Simultaneous optical polarimetry observations taken at the SAAO 1.9 m give a non-detection with an upper limit of 0.07%. For the given spectral types and absolute magnitudes, 1 Gyr theoretical models predict masses of 0.04-0.05 M{sub Sun} for the primary, and 0.03-0.05 M{sub Sun} for the secondary.

  7. Phenomenology of Dirac Neutralino Dark Matter

    SciTech Connect (OSTI)

    Buckley, Matthew R.; Hooper, Dan; Kumar, Jason

    2013-09-01

    In supersymmetric models with an unbroken R-symmetry (rather than only R-parity), the neutralinos are Dirac fermions rather than Majorana. In this article, we discuss the phenomenology of neutralino dark matter in such models, including the calculation of the thermal relic abundance, and constraints and prospects for direct and indirect searches. Due to the large elastic scattering cross sections with nuclei predicted in R-symmetric models, we are forced to consider a neutralino that is predominantly bino, with very little higgsino mixing. We find a large region of parameter space in which bino-like Dirac neutralinos with masses between 10 and 380 GeV can annihilate through slepton exchange to provide a thermal relic abundance in agreement with the observed cosmological density, without relying on coannihilations or resonant annihilations. The signatures for the indirect detection of Dirac neutralinos are very different than predicted in the Majorana case, with annihilations proceeding dominately to $\\tau^+ \\tau^-$, $\\mu^+ \\mu^-$ and $e^+ e^-$ final states, without the standard chirality suppression. And unlike Majorana dark matter candidates, Dirac neutralinos experience spin-independent scattering with nuclei through vector couplings (via $Z$ and squark exchange), leading to potentially large rates at direct detection experiments. These and other characteristics make Dirac neutralinos potentially interesting within the context of recent direct and indirect detection anomalies. We also discuss the case in which the introduction of a small Majorana mass term breaks the $R$-symmetry, splitting the Dirac neutralino into a pair of nearly degenerate Majorana states.

  8. Accurately Analyzing Malaria Tests a Matter of Life and Death | GE Global

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsicloudden DocumentationAccommodations Accommodations LosUnderground Reservoirs -

  9. TEE-0074 - In the Matter of GE Appliances & Lighting | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergyPlan | Department ofSUPPLEMENTSwitzerland|ofSessions |2Energy 71 - In3 -4

  10. TEE-0077 - In the Matter of GE Appliances & Lighting | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergyPlan | Department ofSUPPLEMENTSwitzerland|ofSessions |2Energy 71 - In37 -

  11. VEA-0016 - In the Matter of GE Appliances | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematics And Statistics » USAJobs Search USAJobs SearchWater-SavingofCode | Department2 16 I N S|5 - In6 -

  12. Dark matter vs. astrophysics in the interpretation of AMS-02 electron and positron data

    E-Print Network [OSTI]

    Mattia Di Mauro; Fiorenza Donato; Nicolao Fornengo; Andrea Vittino

    2015-07-24

    We perform a detailed quantitative analysis of the recent AMS-02 electron and positron data. We investigate the interplay between the emission from primary astrophysical sources, namely Supernova Remnants and Pulsar Wind Nebulae, and the contribution from a dark matter annihilation or decay signal. Our aim is to assess the information that can be derived on dark matter properties when both dark matter and primary astrophysical sources are assumed to jointly contribute to the leptonic observables measured by the AMS-02 experiment. We investigate both the possibility to set robust constraints on the dark matter annihilation/decay rate and the possibility to look for dark matter signals within realistic models that take into account the full complexity of the astrophysical background. Our results show that AMS-02 data enable to probe efficiently vast regions of the dark matter parameter space and, in some cases, to set constraints on the dark matter annihilation/decay rate that are comparable or even stronger with respect to the ones that can be derived from other indirect detection channels. For dark matter annihilation into muons, the bounds leave room for a possible joint DM+astro interpretation of the data, with a dark matter mass in the 50-80 GeV range (depending on the pulsars modeling) and an annihilation cross section in the range (0.7 {\\div} 3) times the thermal cross section.

  13. LtBlue-LessInk

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    7 th Plan supply curve review and regional tool Brown Bag March 5, 2014 B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 2 BACKGROUND DATA COLLECTION DATA ANALYSIS MARKET...

  14. LtBlue-LessInk

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    by sector, end use, and measure category.. WHAT IT INCLUDES 35 Individual supply curve measure data including savings, levelized costs, and ramp rates. YOU CAN CALCULATE Economic...

  15. LT7484 2..5

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousand CubicResource andfirst

  16. LtBlue-LessInk

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousandReport) | SciTech Connect Lower-Energy Energy Storage7 th

  17. LtBlue-LessInk

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousandReport) | SciTech Connect Lower-Energy Energy Storage7 th7

  18. LtBlue-LessInk

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousandReport) | SciTech Connect Lower-Energy Energy Storage7

  19. LtBlue-LessInk

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousandReport) | SciTech Connect Lower-Energy Energy Storage7AGENDA

  20. LtBlue-LessInk

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousandReport) | SciTech Connect Lower-Energy Energy

  1. LtBlue-LessInk

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousandReport) | SciTech Connect Lower-Energy EnergyLighting Brown

  2. Cs6Ge8Zn: A Zintl Phase with Isolated Heteroatomic Clusters of Ge8Zn

    E-Print Network [OSTI]

    a single phase of Cs6Ge8Zn.8 The plate-like crystals of the compound are brittle, black, and with coal-like luster. Single-crystal studies unveiled a new type of cluster formation, a dimer of corner different types. The clusters of type A have only a horizontal mirror plane (Cm) while the clusters of type

  3. Dark Matter and the Baryon Asymmetry of the Universe

    E-Print Network [OSTI]

    Glennys R. Farrar; Gabrijela Zaharijas

    2004-07-06

    We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\\sigma^{\\rm annih}_{\\bar{X}} < \\sigma^{\\rm annih}_{X} $, the $\\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If $m_X \\lsi 4.5 B_X $GeV and the annihilation cross sections differ by $\\gsi 10%$, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$.

  4. Structure and vibrations of different charge Ge impurity in ?-quartz

    SciTech Connect (OSTI)

    Kislov, A. N., E-mail: a.n.kislov@urfu.ru; Mikhailovich, A. P., E-mail: a.n.kislov@urfu.ru; Zatsepin, A. F., E-mail: a.n.kislov@urfu.ru [Ural Federal University, 19 Mira St., Yekaterinburg, 620002 (Russian Federation)

    2014-10-21

    Atomic structure and localized vibrations of ??SiO{sub 2}:Ge are studied using computer modeling techniques. The simulation was carried out by the lattice dynamics calculation of the local density of vibrational states. Local structures parameters are calculated, localized symmetrized vibrations frequency caused by Ge impurity in different charge states are defined. The movements of atoms located near Ge impurity are analyzed and their contribution into localized vibrations of different type is evaluated.

  5. The Characterization of the Gamma-Ray Signal from the Central Milky Way: A Compelling Case for Annihilating Dark Matter

    SciTech Connect (OSTI)

    Daylan, Tansu; Finkbeiner, Douglas P.; Hooper, Dan; Linden, Tim; Portillo, Stephen K. N.; Rodd, Nicholas L.; Slatyer, Tracy R.

    2014-02-26

    Past studies have identified a spatially extended excess of ~1-3 GeV gamma rays from the region surrounding the Galactic Center, consistent with the emission expected from annihilating dark matter. We revisit and scrutinize this signal with the intention of further constraining its characteristics and origin. By applying cuts to the Fermi event parameter CTBCORE, we suppress the tails of the point spread function and generate high resolution gamma-ray maps, enabling us to more easily separate the various gamma-ray components. Within these maps, we find the GeV excess to be robust and highly statistically significant, with a spectrum, angular distribution, and overall normalization that is in good agreement with that predicted by simple annihilating dark matter models. For example, the signal is very well fit by a 31-40 GeV dark matter particle annihilating to b quarks with an annihilation cross section of sigma v = (1.4-2.0) x 10^-26 cm^3/s (normalized to a local dark matter density of 0.3 GeV/cm^3). Furthermore, we confirm that the angular distribution of the excess is approximately spherically symmetric and centered around the dynamical center of the Milky Way (within ~0.05 degrees of Sgr A*), showing no sign of elongation along or perpendicular to the Galactic Plane. The signal is observed to extend to at least 10 degrees from the Galactic Center, disfavoring the possibility that this emission originates from millisecond pulsars.

  6. The Proposed Majorana 76Ge Double-Beta Decay Experiment

    SciTech Connect (OSTI)

    Aalseth, Craig E.; Anderson, Dale N.; Arthur, Richard J.; Avignone, Frank T.; Baktash, Cryus; Ball, Thedore; Barabash, Alexander S.; Bertrand, F.; Brodzinski, Ronald L.; Brudanin, V.; Bugg, William; Champagne, A. E.; Chan, Yuen-Dat; Cianciolo, Thomas V.; Collar, J. I.; Creswick, R. W.; Descovich, M.; Di Marco, Marie; Doe, P. J.; Dunham, Glen C.; Efremenko, Yuri; Egerov, V.; Ejiri, H.; Elliott, Steven R.; Emanuel, A.; Fallon, Paul; Farach, H. A.; Gaitskell, R. J.; Gehman, Victor; Grzywacz, Robert; Hallin, A.; Hazma, R.; Henning, R.; Hime, Andrew; Hossbach, Todd W.; Jordan, David V.; Kazkaz, K.; Kephart, Jeremy; King, G. S.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Lesko, Kevin; Luke, P.; Luzum, M.; Macchiavelli, A. O.; McDonald, A.; Mei, Dongming; Miley, Harry S.; Mills, G. B.; Mokhtarani, A.; Nomachi, Masaharu; Orrell, John L.; Palms, John M.; Poon, Alan; Radford, D. C.; Reeves, James H.; Robertson, R. G. H.; Runkle, Robert C.; Rykaczewski, Krzysztof P.; Saburov, Konstantin; Sandukovsky, Viatcheslav; Sonnenschein, Andrew; Tornow, W.; Tull, C.; van de Water, R. G.; Vanushin, Igor; Vetter, Kai; Warner, Ray A.; Wilkerson, John F.; Wouters, Jan M.; Young , A. R.; Yumatov, V.

    2005-01-01

    The proposed Majorana experiment is based on an array of segmented intrinsic Ge detectors with a total mass of 500 kg of Ge isotopically enriched to 86% in 76Ge. Background reduction will be accomplished by: material selection, detector segmentation, pulse shape analysis, electro-formation of copper parts, and granularity of detector spacing. The predicted experimental sensitivity for measurement of the neutrinoless double-beta decay mode of 76Ge, over a data acquisition period of 5000 kg•y, is ~ 4?1027 y.

  7. GE funds initiative to support STEM initiatives in Oklahoma ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    investment in Oklahoma reflects GE's commitment to skills development for the future. "Growth and development go hand-in-hand with educational excellence, strength in science,...

  8. CMC technology revolutionary for aviation, power | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in new window) Novel CMC technology revolutionizes aircraft engines, turbines CMCs - Ceramic Matrix Composites - are a revolutionary material invented by GE scientists that offer...

  9. Heteroepitaxial Ge-on-Si by DC magnetron sputtering

    SciTech Connect (OSTI)

    Steglich, Martin; Schrempel, Frank; Füchsel, Kevin; Kley, Ernst-Bernhard; Patzig, Christian; Berthold, Lutz; Höche, Thomas; Tünnermann, Andreas; Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Albert-Einstein-Str. 7, 07745 Jena

    2013-07-15

    The growth of Ge on Si(100) by DC Magnetron Sputtering at various temperatures is studied by Spectroscopic Ellipsometry and Transmission Electron Microscopy. Smooth heteroepitaxial Ge films are prepared at relatively low temperatures of 380°C. Typical Stransky-Krastanov growth is observed at 410°C. At lower temperatures (320°C), films are essentially amorphous with isolated nanocrystallites at the Si-Ge interface. A minor oxygen contamination at the interface, developing after ex-situ oxide removal, is not seen to hinder epitaxy. Compensation of dislocation-induced acceptors in Ge by sputtering from n-doped targets is proposed.

  10. Construction progresses at GE's Oil & Gas Technology Center ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Home > Impact > Construction progressing at GE's newest research center, the Oil & Gas Technology Center in Oklahoma City Click to email this to a friend (Opens in new window)...

  11. RADIATION DAMAGE RESISTANCE OF REVERSE ELECTRODE GE COAXIAL DETECTORS

    E-Print Network [OSTI]

    Pehl, Richard H.

    2011-01-01

    Parker, "Radiation Damage of Germanium Detectors", Bull. Am.to radiation damage between the two detectors was clearlyRADIATION DAMAGE RESISTANCE OF REVERSE ELECTRODE GE COAXIAL DETECTORS

  12. GE China Technology Center Wins Top 12 Most Innovative Practices...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to our local markets and innovating technologies to meet the most urgent needs of Chinese society. Additionally, GE teams up with local customers to jointly develop innovative...

  13. The Wizard of Schenectady: Charles Proteus Steinmetz | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    week the Smithsonian's "Past Imperfect" blog highlighted a man near and dear to the heart of GE Global Research, Charles Proteus Steinmetz. The article paints a really...

  14. Big Data and Analytics at Work | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    time analytics is required At GE we keep pace with these trends via the Industrial Internet, a highly connected ecosystem of intelligent machines, advanced analytics and people...

  15. A Sneak Peek Into Santa's Smarter Sleigh | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    legs a break. - An upgraded sleigh frame made from GE's high temperature Ceramic Matrix Composites (CMCs). The CMCs can withstand the heat of entry and reentry in earth's...

  16. Titan propels GE wind turbine research into new territory | ornl...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Titan propels GE wind turbine research into new territory January 17, 2014 The amount of global electricity supplied by wind, the world's fastest growing energy source, is expected...

  17. Thoughts From the 2012 Whitney Software Symposium | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Big Data, Modeling and Simulation, High Performance Computing and the Industrial Internet as key technological enablers of GE's Software initiatives. We enjoyed speakers from...

  18. EEDP and Other Leadership Programs | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ready to dive in? Apply for the program. GE Software Leadership Program The rise of the Industrial Internet requires a new breed of talent and organizational capability. New...

  19. Too massive neutron stars: The role of dark matter?

    E-Print Network [OSTI]

    Ang Li; Feng Huang; Ren-Xin Xu

    2012-08-18

    The maximum mass of a neutron star is generally determined by the equation of state of the star material. In this study, we take into account dark matter particles, assumed to behave like fermions with a free parameter to account for the interaction strength among the particles, as a possible constituent of neutron stars. We find dark matter inside the star would soften the equation of state more strongly than that of hyperons, and reduce largely the maximum mass of the star. However, the neutron star maximum mass is sensitive to the particle mass of dark matter, and a very high neutron star mass larger than 2 times solar mass could be achieved when the particle mass is small enough. Such kind of dark-matter- admixed neutron stars could explain the recent measurement of the Shapiro delay in the radio pulsar PSR J1614-2230, which yielded a neutron star mass of 2 times solar mass that may be hardly reached when hyperons are considered only, as in the case of the microscopic Brueckner theory. Furthermore, in this particular case, we point out that the dark matter around a neutron star should also contribute to the mass measurement due to its pure gravitational effect. However, our numerically calculation illustrates that such contribution could be safely ignored because of the usual diluted dark matter environment assumed. We conclude that a very high mass measurement of about 2 times solar mass requires a really stiff equation of state in neutron stars, and find a strong upper limit (<= 0.64 GeV) for the particle mass of non-self- annihilating dark matter based on the present model.

  20. WIMP matter power spectra and small scale power generation

    E-Print Network [OSTI]

    C. Boehm; H. Mathis; J. Devriendt; J. Silk

    2003-09-24

    Dark Matter (DM) is generally assumed to be massive, cold and collisionless from the structure formation point of view. A more correct statement however is that DM indeed experiences collisional damping, but on a scale which is supposed to be too small to be relevant for structure formation. The aim of this paper is to present a Cold (although ``collisional'') Dark Matter particle whose matter power spectrum is damped and see whether it is distinguishable from standard candidates. To achieve this purpose, we calculate the collisional damping and free-streaming scales of neutralinos and non conventional candidates (say light particles heavier than ~1 MeV but lighter than O(10) GeV). The latter can be considered as Cold Dark Matter (CDM) particles in the sense that they become non relativistic before their thermal decoupling epoch. Unlike neutralinos, however, their linear matter power spectrum can be damped on scales of ~ 10^3 Msol due to their interactions. Since these scales are of cosmological interest for structure formation, we perform a series of numerical simulations to obtain the corresponding non linear matter power spectra P(k)_{nl} at the present epoch. We show that because of small scale regeneration, they all resemble each other at low redshifts, i.e. become very similar to a typical CDM matter power spectrum on all but the smallest scales. Therefore, even if lensing measurements at redshift below unity were to yield a P(k)_{nl} consistent with CDM models, this would not constitute a sufficiently robust evidence in favour of the neutralino to rule out alternative DM candidates.

  1. Response of a proportional counter to $^{37}$Ar and $^{71}$Ge: real spectra versus GEANT4 simulation

    E-Print Network [OSTI]

    D. Abdurashitov; Yu. Malyshkin; V. Matushko; B. Suerfu

    2015-09-09

    The energy deposition spectra of $^{37}$Ar and $^{71}$Ge in a miniature proportional counter are measured and compared in detail to the model response simulated with Geant4. The spectrum of $^{71}$Ge is measured with total statistics of 1.7$\\cdot$10$^8$ events and is presented for the first time. A certain modification of the Geant4 code, making it possible to trace the deexcitation of atomic shells properly, is suggested. After the modification Geant4 is able to reproduce a response of particle detectors in detail in a keV energy range. This feature is very important in the laboratory experiments that search for massive sterile neutrinos as well as for dark matter directly by detection of recoil nuclei. We expect this work to convince physicists to trust Geant4 simulations at low energies.

  2. Response of a proportional counter to $^{37}$Ar and $^{71}$Ge: real spectra versus GEANT4 simulation

    E-Print Network [OSTI]

    Abdurashitov, D; Matushko, V; Suerfu, B

    2015-01-01

    The energy deposition spectra of $^{37}$Ar and $^{71}$Ge in a miniature proportional counter are measured and compared in detail to the model response simulated with Geant4. The spectrum of $^{71}$Ge is measured with total statistics of 1.7$\\cdot$10$^8$ events and is presented for the first time. A certain modification of the Geant4 code, making it possible to trace the deexcitation of atomic shells properly, is suggested. After the modification Geant4 is able to reproduce a response of particle detectors in detail in a keV energy range. This feature is very important in the laboratory experiments that search for massive sterile neutrinos as well as for dark matter directly by detection of recoil nuclei. We expect this work to convince physicists to trust Geant4 simulations at low energies.

  3. Structural and optical properties of GaAs-based heterostructures with Ge and Ge/InGaAs quantum wells

    SciTech Connect (OSTI)

    Aleshkin, V. Ya.; Dubinov, A. A., E-mail: sanya@ipm.sci-nnov.ru; Drozdov, M. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Zvonkov, B. N. [Nizhni Novgorod State University, Research Physical Technical Institute (Russian Federation); Kudryavtsev, K. E.; Tonkikh, A. A.; Yablonskiy, A. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Werner, P. [Max Planck Institute of Microstructure Physics (Germany)

    2013-05-15

    GaAs-based heterostructures with Ge and Ge/InGaAs quantum wells are grown by laser-assisted sputtering. Structural and optical studies of the heterostructures are carried out. A broad photoluminescence line is observed in the wavelength range from 1300 to 1650 nm. The line corresponds to indirect transitions in the momentum space of the Ge quantum wells and to transitions between the In{sub 0.28}Ga{sub 0.72}As and Ge layers, indirect in coordinate space, but direct in momentum space.

  4. Axion Dark Matter Searches

    E-Print Network [OSTI]

    I. Stern

    2014-03-21

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a $\\mu$eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 $\\mu$eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  5. Axion Dark Matter Searches

    E-Print Network [OSTI]

    Stern, I

    2014-01-01

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a $\\mu$eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 $\\mu$eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  6. Thermodynamics of clusterized matter

    E-Print Network [OSTI]

    Ad. R. Raduta; F. Gulminelli

    2009-08-26

    Thermodynamics of clusterized matter is studied in the framework of statistical models with non-interacting cluster degrees of freedom. At variance with the analytical Fisher model, exact Metropolis simulation results indicate that the transition from homogeneous to clusterized matter lies along the $\\rho=\\rho_0$ axis at all temperatures and the limiting point of the phase diagram is not a critical point even if the surface energy vanishes at this point. Sensitivity of the inferred phase diagram to the employed statistical framework in the case of finite systems is discussed by considering the grand-canonical and constant-pressure canonical ensembles. A Wigner-Seitz formalism in which the fragment charge is neutralized by an uniform electron distribution allows to build the phase diagram of neutron star matter.

  7. Natural minimal dark matter

    E-Print Network [OSTI]

    Fabbrichesi, Marco

    2015-01-01

    We show how the Higgs boson mass is protected from the potentially large corrections due to the introduction of minimal dark matter if the new physics sector is made supersymmetric. The fermionic dark matter candidate (a 5-plet of $SU(2)_L$) is accompanied by a scalar state. The weak gauge sector is made supersymmetric and the Higgs boson is embedded in a supersymmetric multiplet. The remaining standard model states are non-supersymmetric. Non vanishing corrections to the Higgs boson mass only appear at three-loop level and the model is natural for dark matter masses up to 15 TeV--a value larger than the one required by the cosmological relic density. The construction presented stands as an example of a general approach to naturalness that solves the little hierarchy problem which arises when new physics is added beyond the standard model at an energy scale around 10 TeV.

  8. Axion Dark Matter Searches

    E-Print Network [OSTI]

    I. Stern

    2015-11-17

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a $\\mu$eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 $\\mu$eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  9. Cold nuclear matter

    E-Print Network [OSTI]

    C. O. Dorso; P. A. Giménez Molinelli; J. I. Nichols; J. A. López

    2013-05-09

    The behavior of nuclear matter is studied at low densities and temperatures using classical molecular dynamics with three different sets of potentials with different compressibility. Nuclear matter is found to arrange in crystalline structures around the saturation density and in non-homogeneous (i.e. pasta-like) structures at lower densities. Similar results were obtained with a simple Lennard-Jones potential. Finite size effects are analysed and the existence of the non-homogeneous structures is shown to be inherent to the use of periodic boundary conditions and the finitude of the system. For large enough systems the non-homogeneous structures are limited to one sphere, one rod or one slab per simulation cell, which are shown to be minimal surface structures under cubic periodic boundary conditions at the corresponding volume fraction. The relevance of these findings to the simulations of neutron star and supernovae matter is discussed.

  10. Asymptotically Safe Dark Matter

    E-Print Network [OSTI]

    Francesco Sannino; Ian M. Shoemaker

    2015-08-05

    We introduce a new paradigm for dark matter (DM) interactions in which the interaction strength is asymptotically safe. In models of this type, the coupling strength is small at low energies but increases at higher energies, and asymptotically approaches a finite constant value. The resulting phenomenology of this "asymptotically safe DM" is quite distinct. One interesting effect of this is to partially offset the low-energy constraints from direct detection experiments without affecting thermal freeze-out processes which occur at higher energies. High-energy collider and indirect annihilation searches are the primary ways to constrain or discover asymptotically safe dark matter.

  11. Safe Dark Matter

    E-Print Network [OSTI]

    Francesco Sannino; Ian M. Shoemaker

    2015-07-29

    We introduce a new paradigm for dark matter (DM) interactions in which the interaction strength is asymptotically safe. In models of this type, the coupling strength is small at low energies but increases at higher energies, and asymptotically approaches a finite constant value. The resulting phenomenology of this "safe DM" is quite distinct. One interesting effect of this is to partially offset the low-energy constraints from direct detection experiments without affecting thermal freeze-out processes which occur at higher energies. High-energy collider and indirect annihilation searches are the primary ways to constrain or discover safe dark matter.

  12. Shell model description of Ge isotopes

    E-Print Network [OSTI]

    J. G. Hirsch; P. C. Srivastava

    2012-04-12

    A shell model study of the low energy region of the spectra in Ge isotopes for $38\\leq N\\leq 50$ is presented, analyzing the excitation energies, quadrupole moments, $B(E2)$ values and occupation numbers. The theoretical results have been compared with the available experimental data. The shell model calculations have been performed employing three different effective interactions and valence spaces.We have used two effective shell model interactions, JUN45 and jj44b, for the valence space $f_{5/2} \\, p \\,g_{9/2}$ without truncation. To include the proton subshell $f_{7/2}$ in valence space we have employed the $fpg$ effective interaction due to Sorlin {\\it et al.}, with $^{48}$Ca as a core and a truncation in the number of excited particles.

  13. 3 GeV Injector Design Handbook

    SciTech Connect (OSTI)

    Wiedemann, H.; /SLAC, SSRL

    2009-12-16

    This Design Handbook is intended to be the main reference book for the specifications of the 3 GeV SPEAR booster synchrotron project. It is intended to be a consistent description of the project including design criteria, key technical specifications as well as current design approaches. Since a project is not complete till it's complete changes and modifications of early conceptual designs must be expected during the duration of the construction. Therefore, this Design Handbook is issued as a loose leaf binder so that individual sections can be replaced as needed. Each page will be dated to ease identification with respect to latest revisions. At the end of the project this Design Handbook will have become the 'as built' reference book of the injector for operations and maintenance personnel.

  14. Nucleon Resonances Near 2 GeV

    E-Print Network [OSTI]

    He, Jun

    2015-01-01

    The nucleon resonances near 2 GeV are investigated through the $\\Sigma$(1385) and $\\Lambda(1520)$ photoproductions within a Regge-plus-resonance approach based on the new experimental data released by the CLAS Collaboration. The $\\Delta(2000)$ and the $N(2120)$ are found essential to reproduce the experimental data and should be assigned as second $[\\Delta 5/2^+]$ and third $[N3/2^-]$ in the constituent quark model, respectively. A calculation of the binding energy and decay pattern supports that the $N(1875)$, which is listed in the PDG as the third $N3/2^-$ nucleon resonance instead of the $N(2120)$, is from the $\\Sigma(1385)K$ interaction rather than a three quark state.

  15. Nanostructure and infrared photoluminescence of nanocrystalline Ge formed by reduction of Si0.75Ge0.25O2 Si0.75Ge0.25 using various H2 pressures

    E-Print Network [OSTI]

    Nanostructure and infrared photoluminescence of nanocrystalline Ge formed by reduction of Si0.75Ge0.25O2 ÕSi0.75Ge0.25 using various H2 pressures Gianni Taraschi,a) Sajan Saini, Wendy W. Fan, Lionel C Ge in SiO2 was synthesized by the reduction of Si0.75Ge0.25O2 with H2 , at various annealing

  16. Band-engineered Ge-on-Si lasers

    E-Print Network [OSTI]

    Liu, Jifeng

    We report optically-pumped Ge-on-Si lasers with direct gap emission near 1600 nm at room temperature. The Ge-on-Si material was band-engineered by tensile strain and n-type doping to compensate the energy difference between ...

  17. Ge#ng Started on HokieSpeed

    E-Print Network [OSTI]

    Crawford, T. Daniel

    Ge#ng Started on HokieSpeed Advanced Research Computing #12;Advanced Research Compu:ng;Advanced Research Compu:ng Important Login Informa:on · Account sheets provide login Compu:ng Ge#ng Started Steps 1. Sheet distributed provides your training account

  18. Flavored Dark Matter and the Galactic Center Gamma-Ray Excess

    SciTech Connect (OSTI)

    Agrawal, Prateek; Batell, Brian; Hooper, Dan; Lin, Tongyan

    2014-09-01

    Thermal relic dark matter particles with a mass of 31-40 GeV and that dominantly annihilate to bottom quarks have been shown to provide an excellent description of the excess gamma rays observed from the center of the Milky Way. Flavored dark matter provides a well-motivated framework in which the dark matter can dominantly couple to bottom quarks in a flavor-safe manner. We propose a phenomenologically viable model of bottom flavored dark matter that can account for the spectral shape and normalization of the gamma-ray excess while naturally suppressing the elastic scattering cross sections probed by direct detection experiments. This model will be definitively tested with increased exposure at LUX and with data from the upcoming high-energy run of the Large Hadron Collider (LHC).

  19. Anisotropic dark matter distribution functions and impact on WIMP direct detection

    SciTech Connect (OSTI)

    Bozorgnia, Nassim; Schwetz, Thomas; Catena, Riccardo E-mail: riccardo.catena@theorie.physik.uni-goettingen.de

    2013-12-01

    Dark matter N-body simulations suggest that the velocity distribution of dark matter is anisotropic. In this work we employ a mass model for the Milky Way whose parameters are determined from a fit to kinematical data. Then we adopt an ansatz for the dark matter phase space distribution which allows to construct self-consistent halo models which feature a degree of anisotropy as a function of the radius such as suggested by the simulations. The resulting velocity distributions are then used for an analysis of current data from dark matter direct detection experiments. We find that velocity distributions which are radially biased at large galactocentric distances (up to the virial radius) lead to an increased high velocity tail of the local dark matter distribution. This affects the interpretation of data from direct detection experiments, especially for dark matter masses around 10 GeV, since in this region the high velocity tail is sampled. We find that the allowed regions in the dark matter mass-cross section plane as indicated by possible hints for a dark matter signal reported by several experiments as well as conflicting exclusion limits from other experiments shift in a similar way when the halo model is varied. Hence, it is not possible to improve the consistency of the data by referring to anisotropic halo models of the type considered in this work.

  20. Quantum Condensed Matter | Neutron Science | ORNL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Quantum Condensed Matter SHARE Quantum Condensed Matter Neutron scattering is a uniquely powerful probe for measuring the structure and dynamics of condensed matter. As such it is...

  1. Quantum Condensed Matter | More Science | ORNL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Quantum Condensed Matter SHARE Quantum Condensed Matter Neutron scattering is a uniquely powerful probe for measuring the structure and dynamics of condensed matter. As such it is...

  2. Investigation of Direct Injection Vehicle Particulate Matter...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Direct Injection Vehicle Particulate Matter Emissions Investigation of Direct Injection Vehicle Particulate Matter Emissions This study focuses primarily on particulate matter mass...

  3. Asymmetric condensed dark matter

    E-Print Network [OSTI]

    Aguirre, Anthony

    2015-01-01

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate can be very light, $10^{-22}\\,{\\rm eV} \\lesssim m \\lesssim 10^2\\,{\\rm eV}$; the lower limit arises from constraints on small-scale structure formation, while the upper bound ensures that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of deco...

  4. Tunguska Dark Matter Ball

    E-Print Network [OSTI]

    C. D. Froggatt; H. B. Nielsen

    2015-05-10

    It is suggested that the Tunguska event in June 1908 cm-large was due to a cm-large ball of a condensate of bound states of 6 top and 6 anti-top quarks containing highly compressed ordinary matter. Such balls are supposed to make up the dark matter as we earlier proposed. The expected rate of impact of this kind of dark matter ball with the earth seems to crudely match a time scale of 200 years between the impacts. The main explosion of the Tunguska event is explained in our picture as material coming out from deep within the earth, where it has been heated and compressed by the ball penetrating to a depth of several thousand km. Thus the effect has some similarity with volcanic activity as suggested by Kundt. We discuss the possible identification of kimberlite pipes with earlier Tunguska-like events. A discussion of how the dark matter balls may have formed in the early universe is also given.

  5. Energy Matters - Spring 2002

    SciTech Connect (OSTI)

    2002-03-01

    Quarterly newsletter from DOE's Industrial Technologies Program to promote the use of energy-efficient industrial systems. The focus of the Spring 2002 Issue of Energy Matters focuses on premium energy efficiency systems, with articles on new gas technologies, steam efficiency, the Augusta Newsprint Showcase, and more.

  6. Energy Matters - Fall 2002

    SciTech Connect (OSTI)

    2002-09-01

    Quarterly newsletter from DOE's Industrial Technologies Program to promote the use of energy-efficient industrial systems. This issue focus of this edition of the Energy Matters Newsletter is on energy and environmental issues. Read more about compressed air's role in productivity, making good motor decisions, and more.

  7. Subject Matters Introduction

    E-Print Network [OSTI]

    Subject Matters Introduction The AS and A Level subject choices you make when in Year 11 (or assessing applicants at the University of Cambridge, we consider not only the individual A Level subjects taken but also the combination of these. We generally prefer applicants to have taken certain subjects

  8. Matter & Energy Solar Energy

    E-Print Network [OSTI]

    Rogers, John A.

    See Also: Matter & Energy Solar Energy· Electronics· Materials Science· Earth & Climate Energy at the University of Illinois, the future of solar energy just got brighter. Although silicon is the industry Electronics Over 1.2 Million Electronics Parts, Components and Equipment. www.AlliedElec.com solar energy

  9. Dark Matter Searches

    E-Print Network [OSTI]

    Laura Baudis

    2005-11-29

    More than 90% of matter in the Universe could be composed of heavy particles, which were non-relativistic, or 'cold', when they froze-out from the primordial soup. I will review current searches for these hypothetical particles, both via interactions with nuclei in deep underground detectors, and via the observation of their annihilation products in the Sun, galactic halo and galactic center.

  10. Excess carrier lifetimes in Ge layers on Si

    SciTech Connect (OSTI)

    Geiger, R., E-mail: richard.geiger@psi.ch, E-mail: hans.sigg@psi.ch; Sigg, H., E-mail: richard.geiger@psi.ch, E-mail: hans.sigg@psi.ch [Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Frigerio, J.; Chrastina, D.; Isella, G. [L-NESS, Dipartimento di Fisica del Politecnico di Milano, Via Anzani 42, 22100 Como (Italy); Süess, M. J. [Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Laboratory for Nanometallurgy, Department of Materials Science, ETH Zurich, 8093 Zurich (Switzerland); Scientific Center for Optical and Electron Microscopy (SCOPEM), ETH Zurich, 8093 Zurich (Switzerland); Spolenak, R. [Laboratory for Nanometallurgy, Department of Materials Science, ETH Zurich, 8093 Zurich (Switzerland); Faist, J. [Institute for Quantum Electronics, ETH Zurich, 8093 Zurich (Switzerland)

    2014-02-10

    The excess charge carrier lifetimes in Ge layers grown on Si or germanium-on-insulator are measured by synchrotron based pump-probe transmission spectroscopy. We observe that the lifetimes do not strongly depend on growth parameters and annealing procedure, but on the doping profile. The defect layer at the Ge/Si interface is found to be the main non-radiative recombination channel. Therefore, the longest lifetimes in Ge/Si (2.6?ns) are achieved in sufficiently thick Ge layers with a built-in field, which repels electrons from the Ge/Si interface. Longer lifetimes (5.3?ns) are obtained in overgrown germanium-on-insulator due to the absence of the defective interface.

  11. Supersymmetry and dark matter post LHC8: Why we may expect both axion and WIMP detection

    SciTech Connect (OSTI)

    Baer, Howard [Dep't of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)

    2014-01-01

    In the post-LHC8 era, it is perceived that what is left of SUSY model parameter space is highly finetuned in the EW sector (EWFT). We discuss how conventional measures overestimate EWFT in SUSY theory. Radiatively-driven natural SUSY (RNS) models maintain the SUSY GUT paradigm with low EWFT at 10% level, but are characterized by light higgsinos ~100–300 GeV and a thermal underabundance of WIMP dark matter. Implementing the SUSY DFSZ solution to the strong CP problem explains the small ? parameter but indicates dark matter should be comprised mainly of axions with a small admixture of higgsino-like WIMPs. While RNS might escape LHC14 searches, we would expect ultimately direct detection of both WIMPs and axions. An e?e? collider with ?(s)~500–600 GeV should provide a thorough search for the predicted light higgsinos.

  12. The thermoelectric properties of Ge/SiGe modulation doped superlattices A. Samarelli, L. Ferre Llin, S. Cecchi, J. Frigerio, T. Etzelstorfer et al.

    E-Print Network [OSTI]

    Hague, Jim

    The thermoelectric properties of Ge/SiGe modulation doped superlattices A. Samarelli, L. Ferre Llin thermoelectric properties of Ge/SiGe modulation doped superlattices A. Samarelli,1 L. Ferre Llin,1 S. Cecchi,2 J June 2013) The thermoelectric and physical properties of superlattices consisting of modulation doped

  13. Energy Matters in Washington State Page 1 Energy Matters

    E-Print Network [OSTI]

    Collins, Gary S.

    Energy Matters in Washington State ­ Page 1 Energy Matters in Washington State June 2008 Updated November 2009 Updated and Revised October 2013 Grand Coulee Dam #12;Energy Matters in Washington State ­ Page 2 Copyright © 2013 Washington State University Energy Program. 905 Plum Street SE, P.O. Box 43169

  14. On atomic structure of Ge huts growing on the Ge/Si(001) wetting layer

    SciTech Connect (OSTI)

    Arapkina, Larisa V.; Yuryev, Vladimir A. [A. M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov Street, Moscow, 119991 (Russian Federation)] [A. M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov Street, Moscow, 119991 (Russian Federation)

    2013-09-14

    Structural models of growing Ge hut clusters—pyramids and wedges—are proposed on the basis of data of recent STM investigations of nucleation and growth of Ge huts on the Si(001) surface in the process of molecular beam epitaxy. It is shown that extension of a hut base along <110> directions goes non-uniformly during the cluster growth regardless of its shape. Growing pyramids, starting from the second monolayer, pass through cyclic formation of slightly asymmetrical and symmetrical clusters, with symmetrical ones appearing after addition of every fourth monolayer. We suppose that pyramids of symmetrical configurations composed by 2, 6, 10, etc., monolayers over the wetting layer are more stable than asymmetrical ones. This might explain less stability of pyramids in comparison with wedges in dense arrays forming at low temperatures of Ge deposition. Possible nucleation processes of pyramids and wedges on wetting layer patches from identical embryos composed by 8 dimers through formation of 1 monolayer high 16-dimer nuclei different only in their symmetry is discussed. Schematics of these processes are presented. It is concluded from precise STM measurements that top layers of wetting layer patches are relaxed when huts nucleate on them.

  15. Axion Bose-Einstein Condensation: a model beyond Cold Dark Matter

    E-Print Network [OSTI]

    Yang, Q

    2010-01-01

    Cold dark matter axions form a Bose-Einstein condensate if the axions thermalize. Recently, it was found that they do thermalize when the photon temperature reaches T ~ 100 eV(f/10^12GeV)^1/2 and that they continue to do so thereafter. We discuss the differences between axion BEC and CDM in the linear regime and the non-linear regime of evolution of density perturbations. We find that axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multi-poles.

  16. Axion Bose-Einstein Condensation: a model beyond Cold Dark Matter

    E-Print Network [OSTI]

    Q. Yang

    2010-04-15

    Cold dark matter axions form a Bose-Einstein condensate if the axions thermalize. Recently, it was found that they do thermalize when the photon temperature reaches T ~ 100 eV(f/10^12GeV)^1/2 and that they continue to do so thereafter. We discuss the differences between axion BEC and CDM in the linear regime and the non-linear regime of evolution of density perturbations. We find that axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multi-poles.

  17. Dark Photons from the Center of the Earth: Smoking-Gun Signals of Dark Matter

    E-Print Network [OSTI]

    Jonathan L. Feng; Jordan Smolinsky; Philip Tanedo

    2015-09-24

    Dark matter may be charged under dark electromagnetism with a dark photon that kinetically mixes with the Standard Model photon. In this framework, dark matter will collect at the center of the Earth and annihilate into dark photons, which may reach the surface of the Earth and decay into observable particles. We determine the resulting signal rates, including Sommerfeld enhancements, which play an important role in bringing the Earth's dark matter population to their maximal, equilibrium value. For dark matter masses $m_X \\sim$ 100 GeV - 10 TeV, dark photon masses $m_{A'} \\sim$ MeV - GeV, and kinetic mixing parameters $\\varepsilon \\sim 10^{-9} - 10^{-7}$, the resulting electrons, muons, photons, and hadrons that point back to the center of the Earth are a smoking-gun signal of dark matter that may be detected by a variety of experiments, including neutrino telescopes, such as IceCube, and space-based cosmic ray detectors, such as Fermi-LAT and AMS. We determine the signal rates and characteristics, and show that large and striking signals---such as parallel muon tracks---are possible in regions of the $(m_{A'}, \\varepsilon)$ plane that are not probed by direct detection, accelerator experiments, or astrophysical observations.

  18. Dark Photons from the Center of the Earth: Smoking-Gun Signals of Dark Matter

    E-Print Network [OSTI]

    Feng, Jonathan L; Tanedo, Philip

    2015-01-01

    Dark matter may be charged under dark electromagnetism with a dark photon that kinetically mixes with the Standard Model photon. In this framework, dark matter will collect at the center of the Earth and annihilate into dark photons, which may reach the surface of the Earth and decay into observable particles. We determine the resulting signal rates, including Sommerfeld enhancements, which play an important role in bringing the Earth's dark matter population to their maximal, equilibrium value. For dark matter masses $m_X \\sim$ 100 GeV - 10 TeV, dark photon masses $m_{A'} \\sim$ MeV - GeV, and kinetic mixing parameters $\\varepsilon \\sim 10^{-9} - 10^{-7}$, the resulting electrons, muons, photons, and hadrons that point back to the center of the Earth are a smoking-gun signal of dark matter that may be detected by a variety of experiments, including neutrino telescopes, such as IceCube, and space-based cosmic ray detectors, such as Fermi-LAT and AMS. We determine the signal rates and characteristics, and show ...

  19. The Isotropic Radio Background and Annihilating Dark Matter

    SciTech Connect (OSTI)

    Hooper, Dan; Belikov, Alexander V.; Jeltema, Tesla E.; Linden, Tim; Profumo, Stefano; Slatyer, Tracy R.

    2012-11-01

    Observations by ARCADE-2 and other telescopes sensitive to low frequency radiation have revealed the presence of an isotropic radio background with a hard spectral index. The intensity of this observed background is found to exceed the flux predicted from astrophysical sources by a factor of approximately 5-6. In this article, we consider the possibility that annihilating dark matter particles provide the primary contribution to the observed isotropic radio background through the emission of synchrotron radiation from electron and positron annihilation products. For reasonable estimates of the magnetic fields present in clusters and galaxies, we find that dark matter could potentially account for the observed radio excess, but only if it annihilates mostly to electrons and/or muons, and only if it possesses a mass in the range of approximately 5-50 GeV. For such models, the annihilation cross section required to normalize the synchrotron signal to the observed excess is sigma v ~ (0.4-30) x 10^-26 cm^3/s, similar to the value predicted for a simple thermal relic (sigma v ~ 3 x 10^-26 cm^3/s). We find that in any scenario in which dark matter annihilations are responsible for the observed excess radio emission, a significant fraction of the isotropic gamma ray background observed by Fermi must result from dark matter as well.

  20. Global fits of the dark matter-nucleon effective interactions

    SciTech Connect (OSTI)

    Catena, Riccardo; Gondolo, Paolo E-mail: paolo.gondolo@utah.edu

    2014-09-01

    The effective theory of isoscalar dark matter-nucleon interactions mediated by heavy spin-one or spin-zero particles depends on 10 coupling constants besides the dark matter particle mass. Here we compare this 11-dimensional effective theory to current observations in a comprehensive statistical analysis of several direct detection experiments, including the recent LUX, SuperCDMS and CDMSlite results. From a multidimensional scan with about 3 million likelihood evaluations, we extract the marginalized posterior probability density functions (a Bayesian approach) and the profile likelihoods (a frequentist approach), as well as the associated credible regions and confidence levels, for each coupling constant vs dark matter mass and for each pair of coupling constants. We compare the Bayesian and frequentist approach in the light of the currently limited amount of data. We find that current direct detection data contain sufficient information to simultaneously constrain not only the familiar spin-independent and spin-dependent interactions, but also the remaining velocity and momentum dependent couplings predicted by the dark matter-nucleon effective theory. For current experiments associated with a null result, we find strong correlations between some pairs of coupling constants. For experiments that claim a signal (i.e., CoGeNT and DAMA), we find that pairs of coupling constants produce degenerate results.

  1. Universal Parametrization of Thermal Photon Rates in Hadronic Matter

    E-Print Network [OSTI]

    Matthew Heffernan; Paul Hohler; Ralf Rapp

    2014-11-25

    Electromagnetic (EM) radiation off strongly interacting matter created in high-energy heavy-ion collisions (HICs) encodes information on the high-temperature phases of nuclear matter. Microscopic calculations of thermal EM emission rates are usually rather involved and not readily accessible to broad applications in models of the fireball evolution which are required to compare to experimental data. An accurate and universal parametrization of the microscopic calculations is thus key to honing the theory behind the EM spectra. Here we provide such a parametrization for photon emission rates from hadronic matter, including the contributions from in-medium rho mesons (which incorporate effects from anti-/baryons), as well as Bremsstrahlung from pi-pi scattering. Individual parametrizations for each contribution are numerically determined through nested fitting functions for photon energies from 0.2 to 5 GeV in chemically equilibrated matter of temperatures 100-180 MeV and baryon chemical potentials 0-400 MeV. Special care is taken to extent the parameterizations to chemical off-equilibrium as encountered in HICs after chemical freezeout. This provides a functional description of thermal photon rates within a 20% variation of the microscopically calculated values.

  2. The Search for Dark Matter

    SciTech Connect (OSTI)

    Orrell, John

    2013-11-20

    More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

  3. The Search for Dark Matter

    ScienceCinema (OSTI)

    Orrell, John

    2014-07-24

    More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

  4. Ratio of jet cross sections at root s=630 GeV and 1800 GeV

    E-Print Network [OSTI]

    Baringer, Philip S.; Bean, Alice; Coppage, Don; Hebert, C.

    2001-03-01

    The DO Collaboration has measured the inclusive jet cross section in (p) over barp collisions at roots = 630 GeV. The results for pseudorapidities \\ eta \\ < 0.5 are combined with our previous results at roots = 1800 GeV ...

  5. Dark Matter and Synchrotron Emission from Galactic Center Radio Filaments

    SciTech Connect (OSTI)

    Linden, Tim; Hooper, Dan; Yusef-Zadeh, Farhad

    2011-11-10

    The inner degrees of the Galactic center contain a large population of filamentary structures observed at radio frequencies. These so-called non-thermal radio filaments (NRFs) trace magnetic field lines and have attracted significant interest due to their hard (S_v ~ -0.1 +/- 0.4) synchrotron emission spectra. The origin of these filaments remains poorly understood. We show that the electrons and positrons created through the annihilations of a relatively light (~5-10 GeV) dark matter particle with the cross section predicted for a simple thermal relic can provide a compelling match to the intensity, spectral shape, and flux variation of the NRFs. Furthermore, the characteristics of the dark matter particle necessary to explain the synchrotron emission from the NRFs is consistent with those required to explain the excess gamma-ray emission observed from the Galactic center by the Fermi-LAT, as well as the direct detection signals observed by CoGeNT and DAMA/LIBRA.

  6. Ion Implanted Ge:B Far Infrard Blocked Impurity Band Detectors

    E-Print Network [OSTI]

    Beeman, J.W.; Goyal, S.; Reichertz, L.A.; Haller, E.E.

    2008-01-01

    +16 1.E+15 1.E+14 Depth into Ge Crystal Surface (Å) Figure 5devices does not match that of Ge:Ga photoconductors, whichimplants or stacking devices) Ge IBIB detectors will reach

  7. ALFVEN-WAVE OSCILLATIONS IN A SPHERE, WITH APPLICATIONS TO ELECTRON-HOLE DROPS IN Ge

    E-Print Network [OSTI]

    Markiewicz, R.S.

    2011-01-01

    Rev. B 13,4626 (1976). For Ge(4:2) m is the average of thediscussed for EHD in unstressed Ge (B II )TO ELECI'RON-OOLE DROPS IN Ge R. S. Markiewicz January 1978

  8. NUCLEATION PHENOMENA IN THE FORMATION OF ELECTRON-HOLE DROPS IN Ge

    E-Print Network [OSTI]

    Westervelt, R.M.

    2010-01-01

    lO cjl(K) Symbol erg cm ) Ge - 0.064 T2 Ref. x x Si Ref. T2constructed the ultra-sensitive Ge photodetector which wasand method of mounting. The Ge sample is electrically and

  9. Photo-oxidation of Ge Nanocrystals: Kinetic Measurements by In Situ Raman Spectroscopy

    E-Print Network [OSTI]

    2008-01-01

    Photo-oxidation of Ge Nanocrystals: Kinetic Measurements byBerkeley, CA, 94720 ABSTRACT Ge nanocrystals are formed inthe Raman spectra of the Ge nanocrystals in-situ. The

  10. Ferromagnetism in Mn-Implanted Epitaxially Grown Ge on Si(100)

    E-Print Network [OSTI]

    Guchhait, S.

    2011-01-01

    segregation in Mn-doped Ge”, Journal of Applied Physics 101,Room-temperature ferromagnetism in Ge 1-x Mn x nanowires”,BC high-?/metal gate Ge/C alloy pMOSFETs fabricated directly

  11. Probing Extra Matter in Gauge Mediation Through the Lightest Higgs Boson Mass

    E-Print Network [OSTI]

    Jason L. Evans; Masahiro Ibe; Tsutomu T. Yanagida

    2011-08-17

    We discuss the implications of the excesses in LHC Higgs boson searches on the gauge mediated supersymmetric standard model, for the mass range 120-140\\,GeV. We find that a relatively heavy lightest Higgs boson mass in this range can be reconciled with light SUSY particles, $m_{\\rm gluino}Higgs boson. We also find that the mass of this extra matter can be predicted rather precisely in gauge mediation for a given Higgs boson and gluino mass.

  12. Origins of low resistivity and Ge donor level in Ge ion-implanted ZnO bulk single crystals

    SciTech Connect (OSTI)

    Kamioka, K.; Oga, T.; Izawa, Y.; Kuriyama, K. [College of Engineering and Research Center of Ion Beam Technology, Hosei University Koganei, Tokyo 184-8584 (Japan); Kushida, K. [Departments of Arts and Sciences, Osaka Kyoiku University Kashiwara, Osaka 582-8582 (Japan)

    2013-12-04

    The energy level of Ge in Ge-ion implanted ZnO single crystals is studied by Hall-effect and photoluminescence (PL) methods. The variations in resistivity from ?10{sup 3} ?cm for un-implanted samples to ?10{sup ?2} ?cm for as-implanted ones are observed. The resistivity is further decreased to ?10{sup ?3} ?cm by annealing. The origins of the low resistivity are attributed to both the zinc interstitial (Zn{sub i}) related defects and the electrical activated Ge donor. An activation energy of Ge donors estimated from the temperature dependence of carrier concentration is 102 meV. In PL studies, the new peak at 372 nm (3.33 eV) related to the Ge donor is observed in 1000 °C annealed samples.

  13. GeO{sub 2}/Ge structure submitted to annealing in deuterium: Incorporation pathways and associated oxide modifications

    SciTech Connect (OSTI)

    Bom, N. M.; Soares, G. V.; Hartmann, S.; Bordin, A.; Radtke, C.

    2014-10-06

    Deuterium (D) incorporation in GeO{sub 2}/Ge structures following D{sub 2} annealing was investigated. Higher D concentrations were obtained for GeO{sub 2}/Ge samples in comparison to their SiO{sub 2}/Si counterparts annealed in the same conditions. Oxygen vacancies produced during the annealing step in D{sub 2} constitute defect sites for D incorporation, analogous to defects at the SiO{sub 2}/Si interfacial region. Besides D incorporation, volatilization of the oxide layer is also observed as a consequence of D{sub 2} annealing, especially in the high temperature regime of the present study (>450?°C). In parallel to this volatilization, the stoichiometry and chemical structure of remnant oxide are modified as well. These results evidence the broader impact of forming gas annealing in dielectric/Ge structures with respect to SiO{sub 2}/Si counterparts.

  14. Transient and temperature-dependent phenomena in Ge:Be and Ge:Zn far infrared photoconductors

    SciTech Connect (OSTI)

    Haegel, N.M.

    1985-11-01

    An experimental study of the transient and temperature-dependent behavior of Ge:Be and Ge:Zn photoconductors has been performed under the low background photon flux conditions (p dot approx. = 10/sup 8/ photons/second) typical of astronomy and astrophysics applications. The responsivity of Ge:Be and Ge:Zn detectors is strongly temperature-dependent in closely compensated material, and the effect of compensation on free carrier lifetime in Ge:Be has been measured using the photo-Hall effect technique. Closely compensated material has been obtained by controlling the concentration of novel hydrogen-related shallow acceptor complexes, A(Be,H) and A(Zn,H), which exist in doped crystals grown under a H/sub 2/ atmosphere. A review of selection criteria for multilevel materials for optimum photoconductor performance is included. 55 refs., 47 figs.

  15. Ion beam synthesis of SiGe alloy layers

    SciTech Connect (OSTI)

    Im, Seongil

    1994-05-01

    Procedures required for minimizing structural defects generated during ion beam synthesis of SiGe alloy layers were studied. Synthesis of 200 mm SiGe alloy layers by implantation of 120-keV Ge ions into <100> oriented Si wafers yielded various Ge peak concentrations after the following doses, 2{times}10{sup 16}cm{sup {minus}2}, 3{times}10{sup 16}cm{sup {minus}2} (mid), and 5{times}10{sup 16}cm{sup {minus}2} (high). Following implantation, solid phase epitaxial (SPE) annealing in ambient N2 at 800C for 1 hr. resulted in only slight redistribution of the Ge. Two kinds of extended defects were observed in alloy layers over 3{times}l0{sup 16}cm{sup {minus}2}cm dose at room temperature (RT): end-of-range (EOR) dislocation loops and strain-induced stacking faults. Density of EOR dislocation loops was much lower in alloys produced by 77K implantation than by RT implantation. Decreasing the dose to obtain 5 at% peak Ge concentration prevents strain relaxation, while those SPE layers with more than 7 at% Ge peak show high densities of misfit- induced stacking faults. Sequential implantation of C following high dose Ge implantation (12 at% Ge peak concentration in layer) brought about a remarkable decrease in density of misfit-induced stacking faults. For peak implanted C > 0.55 at%, stacking fault generation in the epitaxial layer was suppressed, owing to strain compensation by C atoms in the SiGe lattice. A SiGe alloy layer with 0.9 at% C peak concentration under a 12 at% Ge peak exhibited the best microstructure. Results indicate that optimum Ge/C ratio for strain compensation is between 11 and 22. The interface between amorphous and regrown phases (a/c interface) had a dramatic morphology change during its migration to the surface. Initial <100> planar interface decomposes into a <111> faceted interface, changing the growth kinetics; this is associated with strain relaxation by stacking fault formation on (111) planes in the a/c interface.

  16. Atomic geometry of mixed Ge-Si dimers in the initial-stage growth of Ge on Si,,001...2 1 X. Chen* and D. K. Saldin

    E-Print Network [OSTI]

    Saldin, Dilano

    Atomic geometry of mixed Ge-Si dimers in the initial-stage growth of Ge on Si,,001...2 1 X. Chen quantitatively the geometry of mixed Ge-Si dimers on a single domain Si 001 2 1 surface by azimuthal scanning core-level photoelectron diffraction. By analyzing Ge 3d diffraction patterns from Ge/Si 001 at 0.1 ML

  17. Search for Dark Matter in Events with One Jet and Missing Transverse Energy in pp? Collisions at ?s=1.96 TeV

    SciTech Connect (OSTI)

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Bai, Y.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calamba, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chung, W. H.; Chung, Y. S.; Ciocci, M. A.; Clark, A.; Clarke, C.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; d’Ascenzo, N.; Datta, M.; de Barbaro, P.; Dell’Orso, M.; Demortier, L.; Deninno, M.; Devoto, F.; d’Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D’Onofrio, M.; Donati, S.; Dong, P.; Dorigo, M.; Dorigo, T.; Ebina, K.; Elagin, A.; Eppig, A.; Erbacher, R.; Errede, S.; Ershaidat, N.; Eusebi, R.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Fox, P. J.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Funakoshi, Y.; Furic, I.; Gallinaro, M.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Halkiadakis, E.; Hamaguchi, A.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harnik, R.; Harr, R. F.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hewamanage, S.; Hocker, A.; Hopkins, W.; Horn, D.; Hou, S.; Hughes, R. E.; Hurwitz, M.; Husemann, U.; Hussain, N.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Klimenko, S.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; LeCompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lin, C.-J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martínez, M.; Mastrandrea, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M. S.; Nielsen, J.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Paramonov, A. A.; Patrick, J.; Pauletta, G.; Paus, C.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.

    2012-05-01

    We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp? collisions at ?s=1.96 TeV corresponding to an integrated luminosity of 6.7 fb?¹ recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction below a dark matter candidate mass of 5 GeV/c², and on spin-dependent interactions up to masses of 200 GeV/c².

  18. Search for Dark Matter in Events with One Jet and Missing Transverse Energy in pp? Collisions at ?s=1.96 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; et al

    2012-05-23

    We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp? collisions at ?s=1.96 TeV corresponding to an integrated luminosity of 6.7 fb?¹ recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction belowmore »a dark matter candidate mass of 5 GeV/c², and on spin-dependent interactions up to masses of 200 GeV/c².« less

  19. Medical Imaging Technology | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on dark matter By SarahMODELING Release date: Todd A.FebruaryMaking

  20. The Majorana Demonstrator: A Search for Neutrinoless Double-beta Decay of 76Ge

    E-Print Network [OSTI]

    Majorana Collaboration; W. Xu; N. Abgrall; F. T. Avignone III; A. S. Barabash; F. E. Bertrand; V. Brudanin; M. Busch; M. Buuck; D. Byram; A. S. Caldwell; Y-D. Chan; C. D. Christofferson; C. Cuesta; J. A. Detwiler; Yu. Efremenko; H. Ejiri; S. R. Elliott; A. Galindo-Uribarri; G. K. Giovanetti; J. Goett; M. P. Green; J. Gruszko; I. Guinn; V. E. Guiseppe; R. Henning; E. W. Hoppe; S. Howard; M. A. Howe; B. R. Jasinski; K. J. Keeter; M. F. Kidd; S. I. Konovalov; R. T. Kouzes; B. D. LaFerriere; J. Leon; J. MacMullin; R. D. Martin; S. J. Meijer; S. Mertens; J. L. Orrell; C. O'Shaughnessy; N. R. Overman; A. W. P. Poon; D. C. Radford; J. Rager; K. Rielage; R. G. H. Robertson; E. Romero-Romero; M. C. Ronquest; B. Shanks; M. Shirchenko; N. Snyder; A. M. Suriano; D. Tedeschi; J. E. Trimble; R. L. Varner; S. Vasilyev; K. Vetter; K. Vorren; B. R. White; J. F. Wilkerson; C. Wiseman; E. Yakushev; C-H. Yu; V. Yumatov

    2015-05-09

    Neutrinoless double-beta decay is a hypothesized process where in some even-even nuclei it might be possible for two neutrons to simultaneously decay into two protons and two electrons without emitting neutrinos. This is possible only if neutrinos are Majorana particles, i.e. fermions that are their own antiparticles. Neutrinos being Majorana particles would explicitly violate lepton number conservation, and might play a role in the matter-antimatter asymmetry in the universe. The observation of neutrinoless double-beta decay would also provide complementary information related to neutrino masses. The Majorana Collaboration is constructing the Majorana Demonstrator, a 40-kg modular germanium detector array, to search for the Neutrinoless double-beta decay of 76Ge and to demonstrate a background rate at or below 3 counts/(ROI-t-y) in the 4 keV region of interest (ROI) around the 2039 keV Q-value for 76Ge Neutrinoless double-beta decay. In this paper, we discuss the physics of neutrinoless double beta decay and then focus on the Majorana Demonstrator, including its design and approach to achieve ultra-low backgrounds and the status of the experiment.

  1. The MAJORANA DEMONSTRATOR: A search for neutrinoless double-beta decay of ??Ge

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, W.; Abgrall, N.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Brudanin, V.; Busch, M.; Buuck, M.; Byram, D.; Caldwell, A. S.; et al

    2015-05-01

    Neutrinoless double-beta (0???) decay is a hypothesized process where in some even-even nuclei it might be possible for two neutrons to simultaneously decay into two protons and two electrons without emitting neutrinos. This is possible only if neutrinos are Majorana particles, i.e. fermions that are their own antiparticles. Neutrinos being Majorana particles would explicitly violate lepton number conservation, and might play a role in the matter-antimatter asymmetry in the universe. The observation of neutrinoless double-beta decay would also provide complementary information related to neutrino masses. The Majorana Collaboration is constructing the MAJORANA DEMONSTRATOR, with a total of 40-kg Germanium detectors,more »to search for the 0??? decay of ??Ge and to demonstrate a background rate at or below 3 counts/(ROI•t•y) in the 4 keV region of interest (ROI) around the 2039 keV Q-value for ??Ge 0??? decay. In this paper, we discuss the physics of neutrinoless double beta decay and then focus on the MAJORANA DEMONSTRATOR, including its design and approach to achieve ultra-low backgrounds and the status of the experiment.« less

  2. The Majorana Demonstrator: A Search for Neutrinoless Double-beta Decay of 76Ge

    E-Print Network [OSTI]

    Xu, W; Avignone, F T; Barabash, A S; Bertrand, F E; Brudanin, V; Busch, M; Buuck, M; Byram, D; Caldwell, A S; Chan, Y-D; Christofferson, C D; Cuesta, C; Detwiler, J A; Efremenko, Yu; Ejiri, H; Elliott, S R; Galindo-Uribarri, A; Giovanetti, G K; Goett, J; Green, M P; Gruszko, J; Guinn, I; Guiseppe, V E; Henning, R; Hoppe, E W; Howard, S; Howe, M A; Jasinski, B R; Keeter, K J; Kidd, M F; Konovalov, S I; Kouzes, R T; LaFerriere, B D; Leon, J; MacMullin, J; Martin, R D; Meijer, S J; Mertens, S; Orrell, J L; O'Shaughnessy, C; Overman, N R; Poon, A W P; Radford, D C; Rager, J; Rielage, K; Robertson, R G H; Romero-Romero, E; Ronquest, M C; Shanks, B; Shirchenko, M; Snyder, N; Suriano, A M; Tedeschi, D; Trimble, J E; Varner, R L; Vasilyev, S; Vetter, K; Vorren, K; White, B R; Wilkerson, J F; Wiseman, C; Yakushev, E; Yu, C-H; Yumatov, V

    2015-01-01

    Neutrinoless double-beta decay is a hypothesized process where in some even-even nuclei it might be possible for two neutrons to simultaneously decay into two protons and two electrons without emitting neutrinos. This is possible only if neutrinos are Majorana particles, i.e. fermions that are their own antiparticles. Neutrinos being Majorana particles would explicitly violate lepton number conservation, and might play a role in the matter-antimatter asymmetry in the universe. The observation of neutrinoless double-beta decay would also provide complementary information related to neutrino masses. The Majorana Collaboration is constructing the Majorana Demonstrator, a 40-kg modular germanium detector array, to search for the Neutrinoless double-beta decay of 76Ge and to demonstrate a background rate at or below 3 counts/(ROI-t-y) in the 4 keV region of interest (ROI) around the 2039 keV Q-value for 76Ge Neutrinoless double-beta decay. In this paper, we discuss the physics of neutrinoless double beta decay and...

  3. Possibility of Testing the Light Dark Matter Hypothesis with the Alpha Magnetic Spectrometer

    SciTech Connect (OSTI)

    Hooper, Dan; Xue, Wei

    2013-01-01

    The spectrum and morphology of gamma-rays from the Galactic Center and the spectrum of synchrotron emission observed from the Milky Way's radio filaments have each been interpreted as possible signals of $\\sim$7-10 GeV dark matter particles annihilating in the Inner Galaxy. In dark matter models capable of producing these signals, the annihilations should also generate significant fluxes of $\\sim$7-10 GeV positrons which can lead to a distinctive bump-like feature in local cosmic ray positron spectrum. In this letter, we show that while such a feature would be difficult to detect with PAMELA, it would likely be identifiable by the currently operating AMS experiment. As no known astrophysical sources or mechanisms are likely to produce such a sharp feature, the observation of a positron bump at around 7-10 GeV would significantly strengthen the case for a dark matter interpretation of the reported gamma-ray and radio anomalies.

  4. Optimized dark matter searches in deep observations of Segue 1 with MAGIC

    SciTech Connect (OSTI)

    Aleksi?, J.; Blanch, O.; Ansoldi, S.; Antonelli, L.A.; Bonnoli, G.; Antoranz, P.; Babic, A.; Bangale, P.; De Almeida, U. Barres; Bock, R.K.; Borracci, F.; Barrio, J.A.; Bonnefoy, S.; González, J. Becerra; Berger, K.; Bednarek, W.; Bernardini, E.; Biland, A.; Bretz, T.; Carmona, E. E-mail: jrico@ifae; and others

    2014-02-01

    We present the results of stereoscopic observations of the satellite galaxy Segue 1 with the MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours of good-quality data, this is the deepest observational campaign on any dwarf galaxy performed so far in the very high energy range of the electromagnetic spectrum. We search this large data sample for signals of dark matter particles in the mass range between 100 GeV and 20 TeV. For this we use the full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral features, like those expected from dark matter annihilation or decay. In particular, we focus our search on gamma-rays produced from different final state Standard Model particles, annihilation with internal bremsstrahlung, monochromatic lines and box-shaped signals. Our results represent the most stringent constraints to the annihilation cross-section or decay lifetime obtained from observations of satellite galaxies, for masses above few hundred GeV. In particular, our strongest limit (95% confidence level) corresponds to a ? 500 GeV dark matter particle annihilating into ?{sup +}?{sup ?}, and is of order (?{sub ann}v) ?  1.2 × 10{sup ?24} cm{sup 3} s{sup ?1} — a factor ? 40 above the (?{sub ann}v) ?  thermal value.

  5. The Sensitivity of HAWC to High-Mass Dark Matter Annihilations

    E-Print Network [OSTI]

    A. U. Abeysekara; R. Alfaro; C. Alvarez; J. D. Alvarez; R. Arceo; J. C. Arteaga-Velazquez; H. A. Ayala Solares; A. S. Barber; B. M. Baughman; N. Bautista-Elivar; J. Becerra Gonzalez; E. Belmont; S. Y. BenZvi; D. Berley; M. Bonilla Rosales; J. Braun; R. A. Caballero-Lopez; K. S. Caballero-Mora; A. Carraminana; M. Castillo; U. Cotti; J. Cotzomi; E. de la Fuente; C. De Leon; T. DeYoung; R. Diaz Hernandez; L. Diaz-Cruz; J. C. Diaz-Velez; B. L. Dingus; M. A. DuVernois; R. W. Ellsworth; S. F. E.; D. W. Fiorino; N. Fraija; A. Galindo; F. Garfias; M. M. Gonzalez; J. A. Goodman; V. Grabski; M. Gussert; Z. Hampel-Arias; J. P. Harding; C. M. Hui; P. Huentemeyer; A. Imran; A. Iriarte; P. Karn; D. Kieda; G. J. Kunde; A. Lara; R. J. Lauer; W. H. Lee; D. Lennarz; H. Leon Vargas; E. C. Linares; J. T. Linnemann; M. Longo; R. Luna-Garcia; A. Marinelli; H. Martinez; O. Martinez; J. Martinez-Castro; J. A. J. Matthews; J. McEnery; E. Mendoza Torres; P. Miranda-Romagnoli; E. Moreno; M. Mostafa; L. Nellen; M. Newbold; R. Noriega-Papaqui; T. Oceguera-Becerra; B. Patricelli; R. Pelayo; E. G. Perez-Perez; J. Pretz; C. Riviere; D. Rosa-Gonzalez; J. Ryan; H. Salazar; F. Salesa; A. Sandoval; M. Schneider; S. Silich; G. Sinnis; A. J. Smith; K. Sparks Woodle; R. W. Springer; I. Taboada; P. A. Toale; K. Tollefson; I. Torres; T. N. Ukwatta; L. Villasenor; T. Weisgarber; S. Westerhoff; I. G. Wisher; J. Wood; G. B. Yodh; P. W. Younk; D. Zaborov; A. Zepeda; H. Zhou; K. N. Abazajian

    2014-12-09

    The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi- TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from non-luminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross-section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross-sections below thermal. HAWC should also be sensitive to non-thermal cross-sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross-section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained.

  6. Levitating Dark Matter

    E-Print Network [OSTI]

    Nemanja Kaloper; Antonio Padilla

    2009-10-07

    A sizable fraction of the total energy density of the universe may be in heavy particles with a net dark $U(1)'$ charge comparable to its mass. When the charges have the same sign the cancellation between their gravitational and gauge forces may lead to a mismatch between different measures of masses in the universe. Measuring galactic masses by orbits of normal matter, such as galaxy rotation curves or lensing, will give the total mass, while the flows of dark matter agglomerates may yield smaller values if the gauge repulsion is not accounted for. If distant galaxies which house light beacons like SNe Ia contain such dark particles, the observations of their cosmic recession may mistake the weaker forces for an extra `antigravity', and infer an effective dark energy equation of state smaller than the real one. In some cases, including that of a cosmological constant, these effects can mimic $wdark energy, or superhorizon effects.

  7. Rigid particulate matter sensor

    DOE Patents [OSTI]

    Hall, Matthew (Austin, TX)

    2011-02-22

    A sensor to detect particulate matter. The sensor includes a first rigid tube, a second rigid tube, a detection surface electrode, and a bias surface electrode. The second rigid tube is mounted substantially parallel to the first rigid tube. The detection surface electrode is disposed on an outer surface of the first rigid tube. The detection surface electrode is disposed to face the second rigid tube. The bias surface electrode is disposed on an outer surface of the second rigid tube. The bias surface electrode is disposed to face the detection surface electrode on the first rigid tube. An air gap exists between the detection surface electrode and the bias surface electrode to allow particulate matter within an exhaust stream to flow between the detection and bias surface electrodes.

  8. Self-Interacting Dark Matter

    E-Print Network [OSTI]

    Benjamin D. Wandelt; Romeel Dave; Glennys R. Farrar; Patrick C. McGuire; David N. Spergel; Paul J. Steinhardt

    2000-06-28

    Spergel and Steinhardt have recently proposed the concept of dark matter with strong self-interactions as a means to address numerous discrepancies between observations of dark matter halos on subgalactic scales and the predictions of the standard collisionless dark matter picture. We review the motivations for this scenario and discuss some recent, successful numerical tests. We also discuss the possibility that the dark matter interacts strongly with ordinary baryonic matter, as well as with itself. We present a new analysis of the experimental constraints and re-evaluate the allowed range of cross-section and mass.

  9. Hidden vector dark matter

    E-Print Network [OSTI]

    Thomas Hambye

    2010-03-16

    We show that dark matter could be made of massive gauge bosons whose stability doesn't require to impose by hand any discrete or global symmetry. Stability of gauge bosons can be guaranteed by the custodial symmetry associated to the gauge symmetry and particle content of the model. The particle content we consider to this end is based on a hidden sector made of a vector multiplet associated to a non-abelian gauge group and of a scalar multiplet charged under this gauge group. The hidden sector interacts with the Standard Model particles through the Higgs portal quartic scalar interaction in such a way that the gauge bosons behave as thermal WIMPS. This can lead easily to the observed dark matter relic density in agreement with the other various constraints, and can be tested experimentally in a large fraction of the parameter space. In this model the dark matter direct detection rate and the annihilation cross section can decouple if the Higgs portal interaction is weak.

  10. Cosmology with matter diffusion

    SciTech Connect (OSTI)

    Calogero, Simone; Velten, Hermano E-mail: velten@cce.ufes.br

    2013-11-01

    We construct a viable cosmological model based on velocity diffusion of matter particles. In order to ensure the conservation of the total energy-momentum tensor in the presence of diffusion, we include a cosmological scalar field ? which we identify with the dark energy component of the universe. The model is characterized by only one new degree of freedom, the diffusion parameter ?. The standard ?CDM model can be recovered by setting ? = 0. If diffusion takes place (? > 0) the dynamics of the matter and of the dark energy fields are coupled. We argue that the existence of a diffusion mechanism in the universe may serve as a theoretical motivation for interacting models. We constrain the background dynamics of the diffusion model with Supernovae, H(z) and BAO data. We also perform a perturbative analysis of this model in order to understand structure formation in the universe. We calculate the impact of diffusion both on the CMB spectrum, with particular attention to the integrated Sachs-Wolfe signal, and on the matter power spectrum P(k). The latter analysis places strong constraints on the magnitude of the diffusion mechanism but does not rule out the model.

  11. GeV Emission from Collisional Magnetized Gamma Ray Bursts

    E-Print Network [OSTI]

    P. Mészáros; M. J. Rees

    2011-04-26

    Magnetic fields may play a dominant role in gamma-ray bursts, and recent observations by the Fermi satellite indicate that GeV radiation, when detected, arrives delayed by seconds from the onset of the MeV component. Motivated by this, we discuss a magnetically dominated jet model where both magnetic dissipation and nuclear collisions are important. We show that, for parameters typical of the observed bursts, such a model involving a realistic jet structure can reproduce the general features of the MeV and a separate GeV radiation component, including the time delay between the two. The model also predicts a multi-GeV neutrino component.

  12. Recent results in relativistic heavy ion collisions: from ``a new state of matter'' to "the perfect fluid"

    E-Print Network [OSTI]

    M. J. Tannenbaum

    2006-07-28

    Experimental Physics with Relativistic Heavy Ions dates from 1992 when a beam of 197Au of energy greater than 10A GeV/c first became available at the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL) soon followed in 1994 by a 208Pb beam of 158A GeV/c at the Super Proton Synchrotron (SPS) at CERN (European Center for Nuclear Research). Previous pioneering measurements at the Berkeley Bevalac in the late 1970's and early 1980's were at much lower bombarding energies (~ 1 A GeV/c) where nuclear breakup rather than particle production is the dominant inelastic process in A+A collisions. More recently, starting in 2000, the Relativistic Heavy Ion Collider (RHIC) at BNL has produced head-on collisions of two 100A GeV beams of fully stripped Au ions, corresponding to nucleon-nucleon center-of-mass energy, sqrt(sNN)=200 GeV, total c.m. energy 200A GeV. The objective of this research program is to produce nuclear matter with extreme density and temperature, possibly resulting in a state of matter where the quarks and gluons normally confined inside individual nucleons (r < 1 fm) are free to act over distances an order of magnitude larger. Progress from the period 1992 to the present will be reviewed, with reference to previous results from light ion and proton-proton collisions where appropriate. Emphasis will be placed on the measurements which formed the basis for the announcements by the two major laboratories: "A new state of matter", by CERN on Feb 10, 2000 and "The perfect fluid", by BNL on April 19, 2005.

  13. GE Store for Technology is Open for Business | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFESOpportunities Nuclear Physics (NP)aboutRio deCooperation atThe GE

  14. Greatly improved interfacial passivation of in-situ high ? dielectric deposition on freshly grown molecule beam epitaxy Ge epitaxial layer on Ge(100)

    SciTech Connect (OSTI)

    Chu, R. L. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Liu, Y. C.; Lee, W. C.; Huang, M. L.; Kwo, J., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Lin, T. D.; Hong, M., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Pi, T. W. [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China)

    2014-05-19

    A high-quality high-?/Ge interface has been achieved by combining molecule beam epitaxy grown Ge epitaxial layer and in-situ deposited high ? dielectric. The employment of Ge epitaxial layer has sucessfully buried and/or removed the residue of unfavorable carbon and native oxides on the chemically cleaned and ultra-high vacuum annealed Ge(100) wafer surface, as studied using angle-resolved x-ray photoelectron spectroscopy. Moreover, the scanning tunneling microscopy analyses showed the significant improvements in Ge surface roughness from 3.5?Å to 1?Å with the epi-layer growth. Thus, chemically cleaner, atomically more ordered, and morphologically smoother Ge surfaces were obtained for the subsquent deposition of high ? dielectrics, comparing with those substrates without Ge epi-layer. The capacitance-voltage (C-V) characteristics and low extracted interfacial trap density (D{sub it}) reveal the improved high-?/Ge interface using the Ge epi-layer approach.

  15. Atomic layer-by-layer oxidation of Ge (100) and (111) surfaces by plasma post oxidation of Al{sub 2}O{sub 3}/Ge structures

    SciTech Connect (OSTI)

    Zhang, Rui [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan) [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan); School of Electronic Science and Engineering, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Huang, Po-Chin; Lin, Ju-Chin; Takenaka, Mitsuru; Takagi, Shinichi [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)] [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2013-02-25

    The ultrathin GeO{sub x}/Ge interfaces formed on Ge (100) and (111) surfaces by applying plasma post oxidation to thin Al{sub 2}O{sub 3}/Ge structures are characterized in detail using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy. It is found that the XPS signals assigned to Ge 1+ and the 2+ states in the GeO{sub x} layers by post plasma oxidation have oscillating behaviors on Ge (100) surfaces in a period of {approx}0.3 nm with an increase in the GeO{sub x} thickness. Additionally, the oscillations of the signals assigned to Ge 1+ and 2+ states show opposite phase to each other. The similar oscillation behaviors are also confirmed on Ge (111) surfaces for Ge 1+ and 3+ states in a period of {approx}0.5 nm. These phenomena can be strongly regarded as an evidence of the atomic layer-by-layer oxidation of GeO{sub x}/Ge interfaces on Ge (100) and (111) surfaces.

  16. Investigations of segregation phenomena in highly strained Mn-doped Ge wetting layers and Ge quantum dots embedded in silicon

    SciTech Connect (OSTI)

    Prestat, E., E-mail: eric.prestat@gmail.com; Porret, C.; Favre-Nicolin, V.; Tainoff, D.; Boukhari, M.; Bayle-Guillemaud, P.; Jamet, M.; Barski, A., E-mail: andre.barski@cea.com [INAC, SP2M, CEA and Université Joseph Fourier, 17 rue des Martyrs, 38054 Grenoble (France)

    2014-03-10

    In this Letter, we investigate manganese diffusion and the formation of Mn precipitates in highly strained, few monolayer thick, Mn-doped Ge wetting layers and nanometric size Ge quantum dot heterostructures embedded in silicon. We show that in this Ge(Mn)/Si system manganese always precipitates and that the size and the position of Mn clusters (precipitates) depend on the growth temperature. At high growth temperature, manganese strongly diffuses from germanium to silicon, whereas decreasing the growth temperature reduces the manganese diffusion. In the germanium quantum dots layers, Mn precipitates are detected, not only in partially relaxed quantum dots but also in fully strained germanium wetting layers between the dots.

  17. Direct band gap narrowing in highly doped Ge

    E-Print Network [OSTI]

    Han, Zhaohong

    Direct band gap narrowing in highly doped n-type Ge is observed through photoluminescence measurements by determining the spectrum peak shift. A linear relationship between the direct band gap emission and carrier concentration ...

  18. Growth strategies to control tapering in Ge nanowires

    SciTech Connect (OSTI)

    Periwal, P.; Baron, T., E-mail: thierry.baron@cea.fr; Salem, B.; Bassani, F. [Laboratoire des Technologies de la Microelectronique (LTM), UMR 5129 CNRS-UJF, CEA Grenoble, 17 Rue des Martyrs, 38054 Grenoble (France); Gentile, P. [SiNaPs Laboratory SP2M, UMR-E, CEA/UJF-Grenoble 1, INAC, 38054 Grenoble (France)

    2014-04-01

    We report the effect of PH{sub 3} on the morphology of Au catalyzed Ge nanowires (NWs). Ge NWs were grown on Si (111) substrate at 400?°C in the presence of PH{sub 3}, using vapor-liquid-solid method by chemical vapor deposition. We show that high PH{sub 3}/GeH{sub 4} ratio causes passivation at NW surface. At high PH{sub 3} concentration phosphorous atoms attach itself on NW surface and form a self-protection coating that prevents conformal growth and leads to taper free nanostructures. However, in case of low PH{sub 3} flux the combination of axial and radial growth mechanism occurs resulting in conical structure. We have also investigated axial PH{sub 3}-intrinsic junctions in Ge NWs. The unusual NW shape is attributed to a combination of catalyzed, uncatalyzed and diffusion induced growth.

  19. Nanocrystalline Ge Flash Memories: Electrical Characterization and Trap Engineering

    E-Print Network [OSTI]

    Kan, Eric Win Hong

    Conventional floating gate non-volatile memories (NVMs) present critical issues for device scalability beyond the sub-90 nm node, such as gate length and tunnel oxide thickness reduction. Nanocrystalline germanium (nc-Ge) ...

  20. Discovery of Isotopes of Elements with Z $\\ge$ 100

    E-Print Network [OSTI]

    M. Thoennessen

    2012-03-09

    Currently, 163 isotopes of elements with Z $\\ge$ 100 have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  1. Ge-on-Si laser operating at room temperature

    E-Print Network [OSTI]

    Liu, Jifeng

    Monolithic lasers on Si are ideal for high-volume and large-scale electronic–photonic integration. Ge is an interesting candidate owing to its pseudodirect gap properties and compatibility with Si complementary metal oxide ...

  2. GE launches 'STEM empowers OK' initiative in Oklahoma City |...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    GE, OCAST and OSSM Partner to Launch "STEM Empowers OK" Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new...

  3. "Big Picture" Process Modeling Tools |GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Using process modeling tools to attain cost-effective results for GE customers Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click...

  4. ORNL Partners with GE on New Hybrid | ornl.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    electric storage water heater, positioning GE to be the first company to meet the energy-saving standard. According to DOE, using devices that meet these criteria should save...

  5. Kids Invention: Vision of the Future |GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Bring your Child to Work Day, to student mentoring, teaching in the class room, Invention Convention and Science Day. To take the message nationally, GE teamed up with the...

  6. The Need for Biological Computation System Models | GE Global...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2012.10.09 Hello everyone, I'm Maria Zavodszky and I work in the Computational Biology and Biostatistics Lab at GE Global Research in Niskayuna, New York. This being our...

  7. Demonstration of 2nd Generation Ducted GE "Brillion" Hybrid Water

    E-Print Network [OSTI]

    sharing partners. #12;Project Synopsis Evaluate the performance and demand response (DR) of the Gen II GE/frequency response) in the PNW and nationwide (Lu et al, 2011; Diao et al 2012) The demand response characteristics

  8. Carrier Density Modulation in Ge Heterostructure by Ferroelectric Switching

    SciTech Connect (OSTI)

    Ponath, Patrick; Fredrickson, Kurt; Posadas, Agham B.; Ren, Yuan; Vasudevan, Rama K; Okatan, Mahmut Baris; Jesse, Stephen; Aoki, Toshihiro; McCartney, Martha; Smith, David J; Kalinin, Sergei V; Lai, Keji; Demkov, Alexander A.

    2015-01-01

    The development of nonvolatile logic through direct coupling of spontaneous ferroelectric polarization with semiconductor charge carriers is nontrivial, with many issues, including epitaxial ferroelectric growth, demonstration of ferroelectric switching, and measurable semiconductor modulation. Here we report a true ferroelectric field effect carrier density modulation in an underlying Ge(001) substrate by switching of the ferroelectric polarization in the epitaxial c-axis-oriented BaTiO3 (BTO) grown by molecular beam epitaxy (MBE) on Ge. Using density functional theory, we demonstrate that switching of BTO polarization results in a large electric potential change in Ge. Aberration-corrected electron microscopy confirms the interface sharpness, and BTO tetragonality. Electron-energy-loss spectroscopy (EELS) indicates the absence of any low permittivity interlayer at the interface with Ge. Using piezoelectric force microscopy (PFM), we confirm the presence of fully switchable, stable ferroelectric polarization in BTO that appears to be single domain. Using microwave impedance microscopy (MIM), we clearly demonstrate a ferroelectric field effect.

  9. Technology makes reds "pop" in LED displays | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Reveal and Energy Smart consumer brands, and Evolve(tm), GTx(tm), Immersion(tm), Infusion(tm), Lumination(tm), Albeo(tm) and Tetra commercial brands, all trademarks of GE....

  10. Stellar convective cores as dark matter probes

    E-Print Network [OSTI]

    Jordi Casanellas; Isa M. Brandão; Yveline Lebreton

    2015-05-06

    The recent detection of a convective core in a main-sequence solar-type star is used here to test particular models of dark matter (DM) particles, those with masses and scattering cross sections in the range of interest for the DM interpretation of the positive results in several DM direct detection experiments. If DM particles do not effectively self-annihilate after accumulating inside low-mass stars (e.g. in the asymmetric DM scenario) their conduction provides an efficient mechanism of energy transport in the stellar core. For main-sequence stars with masses between 1.1 and 1.3 Msun, this mechanism may lead to the suppression of the inner convective region expected to be present in standard stellar evolution theory. The asteroseismic analysis of the acoustic oscillations of a star can prove the presence/absence of such a convective core, as it was demonstrated for the first time with the Kepler field main-sequence solar-like pulsator, KIC 2009505. Studying this star we found that the asymmetric DM interpretation of the results in the CoGeNT experiment is incompatible with the confirmed presence of a small convective core in KIC 2009505.

  11. Anti-helium from Dark Matter annihilations

    E-Print Network [OSTI]

    Marco Cirelli; Nicolao Fornengo; Marco Taoso; Andrea Vittino

    2014-10-21

    Galactic Dark Matter (DM) annihilations can produce cosmic-ray anti-nuclei via the nuclear coalescence of the anti-protons and anti-neutrons originated directly from the annihilation process. Since anti-deuterons have been shown to offer a distinctive DM signal, with potentially good prospects of detection in large portions of the DM-particle parameter space, we explore here the production of heavier anti-nuclei, specifically anti-helium. Even more than for anti-deuterons, the DM-produced anti-He flux can be mostly prominent over the astrophysical anti-He background at low kinetic energies, typically below 3-5 GeV/n. However, the larger number of anti-nucleons involved in the formation process makes the anti-He flux extremely small. We therefore explore, for a few DM benchmark cases, whether the yield is sufficient to allow for anti-He detection in current-generation experiments, such as AMS-02. We account for the uncertainties due to the propagation in the Galaxy and to the uncertain details of the coalescence process, and we consider the constraints already imposed by anti-proton searches. We find that only for very optimistic configurations it might be possible to achieve detection with current generation detectors. We estimate that, in more realistic configurations, an increase in experimental sensitivity at low-kinetic energies of about a factor of 500-1000 would allow to start probing DM through the rare cosmic anti-He production.

  12. Strange Particles from Dense Hadronic Matter

    E-Print Network [OSTI]

    Johann Rafelski; Jean Letessier; Ahmed Tounsi

    2002-09-25

    After a brief survey of the remarkable accomplishments of the current heavy ion collision experiments up to 200A GeV, we address in depth the role of strange particle production in the search for new phases of matter in these collisions. In particular, we show that the observed enhancement pattern of otherwise rarely produced multistrange antibaryons can be consistently explained assuming color deconfinement in a localized, rapidly disintegrating hadronic source. We develop the theoretical description of this source, and in particular study QCD based processes of strangeness production in the deconfined, thermal quark-gluon plasma phase, allowing for approach to chemical equilibrium and dynamical evolution. We also address thermal charm production. Using a rapid hadronization model we obtain final state particle yields, providing detailed theoretical predictions about strange particle spectra and yields as function of heavy ion energy. Our presentation is comprehensive and self-contained: we introduce in considerable detail the procedures used in data interpretation, discuss the particular importance of selected experimental results and show how they impact the theoretical developments.

  13. Superconnections and Matter

    E-Print Network [OSTI]

    Roepstorff, G

    1998-01-01

    In a previous paper, the superconnection formalism was used to naturally fit the Higgs field into a U(n) gauge theory where we aimed at the reconstruction of the standard model. The approach provides an alternative to non-commutative geometry. This work is now continued by including matter field (leptons). The essentially new ingredient is the right-handed neutrino field and a new kind of interaction that goes with it. All interactions follow from one Dirac operator associated to a superconnection.

  14. Superconnections and Matter

    E-Print Network [OSTI]

    G. Roepstorff

    2000-08-17

    In a previous paper (hep-th/9801040), the superconnection formalism was used to fit the Higgs field into a U(n) gauge theory with particular emphasis on the n=2 case, aiming at the reconstruction of certain parts of the Standard Model. The approach provides an alternative to the one bases on non-commutative geometry. This work is continued by including matter fields (leptons only). We extend the Standard Model by including the right-handed neutrino field. The possibility of a finite neutrino mass is thus accounted for.

  15. Discrete dark matter

    SciTech Connect (OSTI)

    Hirsch, M.; Morisi, S.; Peinado, E.; Valle, J. W. F. [AHEP Group, Institut de Fisica Corpuscular--C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apartado 22085, E-46071 Valencia (Spain)

    2010-12-01

    We propose a new motivation for the stability of dark matter (DM). We suggest that the same non-Abelian discrete flavor symmetry which accounts for the observed pattern of neutrino oscillations, spontaneously breaks to a Z{sub 2} subgroup which renders DM stable. The simplest scheme leads to a scalar doublet DM potentially detectable in nuclear recoil experiments, inverse neutrino mass hierarchy, hence a neutrinoless double beta decay rate accessible to upcoming searches, while {theta}{sub 13}=0 gives no CP violation in neutrino oscillations.

  16. Thermodynamics of electroweak matter

    E-Print Network [OSTI]

    A. Gynther

    2006-09-21

    This paper is a slightly modified version of the introductory part of a PhD thesis, also containing the articles hep-ph/0303019, hep-ph/0510375 and hep-ph/0512177. We provide a short history of the research of electroweak thermodynamics and a brief introduction to the theory as well as to the necessary theoretical tools needed to work at finite temperatures. We then review computations regarding the pressure of electroweak matter at high temperatures (the full expression of the perturbative expansion of the pressure is given in the appendix) and the electroweak phase diagram at finite chemical potentials. Finally, we compare electroweak and QCD thermodynamics.

  17. Dark Matter Velocity Spectroscopy

    E-Print Network [OSTI]

    Eric G. Speckhard; Kenny C. Y. Ng; John F. Beacom; Ranjan Laha

    2015-07-31

    Dark matter decays or annihilations that produce line-like spectra may be smoking-gun signals. However, even such distinctive signatures can be mimicked by astrophysical or instrumental causes. We show that velocity spectroscopy-the measurement of energy shifts induced by relative motion of source and observer-can separate these three causes with minimal theoretical uncertainties. The principal obstacle has been energy resolution, but upcoming experiments will reach the required 0.1% level. As an example, we show that the imminent Astro-H mission can use Milky Way observations to separate possible causes of the 3.5-keV line. We discuss other applications.

  18. Dark matter axions

    SciTech Connect (OSTI)

    Sikivie, P. (California Univ., Santa Barbara, CA (United States). Inst. for Theoretical Physics Florida Univ., Gainesville, FL (United States). Dept. of Physics)

    1992-01-01

    The physics of axions is briefly reviewed theoretically, and various constraints on the axion mass are recounted. Then the two main contributions to the present cosmological axion energy density, that due to the realignment of the vacuum during the QCD phase transition and that from axions radiated by cosmic axion strings, are discussed. Next, two detection schemes for axions that are sensitive to different mass ranges, an electromagnetic cavity permeated by a strong magnetic field and a system of superconducting wires embedded in a material transparent to microwave radiation, are described. Finally, the phase space structure of cold dark matter galactic halos is considered. (RWR)

  19. Dark matter axions

    SciTech Connect (OSTI)

    Sikivie, P. [California Univ., Santa Barbara, CA (United States). Inst. for Theoretical Physics]|[Florida Univ., Gainesville, FL (United States). Dept. of Physics

    1992-09-01

    The physics of axions is briefly reviewed theoretically, and various constraints on the axion mass are recounted. Then the two main contributions to the present cosmological axion energy density, that due to the realignment of the vacuum during the QCD phase transition and that from axions radiated by cosmic axion strings, are discussed. Next, two detection schemes for axions that are sensitive to different mass ranges, an electromagnetic cavity permeated by a strong magnetic field and a system of superconducting wires embedded in a material transparent to microwave radiation, are described. Finally, the phase space structure of cold dark matter galactic halos is considered. (RWR)

  20. Materials/Condensed Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesse BergkampCentermillion toMSDSMaterials andMaterials/Condensed Matter Print

  1. Search for Dark Matter in the sky in the Fermi era This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Morselli, Aldo

    annihilation of dark matter particles is strong but there are competing astrophysical sources, such as pulsars is providing the measurement of the high energy (7 GeV to 1 TeV) cosmic ray electrons and positrons spectrum mainly on astrophysical sources of cosmic ray electrons and positrons which include the standard primary

  2. Members of a workshop at the tenth IAYC Conference, July 7, 2006 1. ge -hak -te le -ber, ge -fil -te -fish: sha-bes iz a far -ge -ni -gn

    E-Print Network [OSTI]

    Finkel, Raphael

    A SUDE Members of a workshop at the tenth IAYC Conference, July 7, 2006 = 90 4 4 1. ge - hak - te le - ber, ge - fil - te - fish: sha- bes iz a far - ge - ni - gn 2. kha - le gri - vn, ku - gl yoykh: ku - men on di ma - khe - to - nem. 3. shtru - dl, tsi - mes, zi - se kalte: a su - de vos men vet ge

  3. Double-Disk Dark Matter

    E-Print Network [OSTI]

    Fan, JiJi; Randall, Lisa; Reece, Matthew

    2013-01-01

    Based on observational tests and constraints on halo structure, dark matter is generally taken to be cold and essentially collisionless. On the other hand, given the large number of particles and forces in the visible world, a more complex dark sector could be a reasonable or even likely possibility. This hypothesis leads to testable consequences, perhaps portending the discovery of a rich hidden world neighboring our own. We consider a scenario that readily satisfies current bounds that we call Partially Interacting Dark Matter (PIDM). This scenario contains self-interacting dark matter, but it is not the dominant component. Even if PIDM contains only a fraction of the net dark matter density, comparable to the baryonic fraction, the subdominant component's interactions can lead to interesting and potentially observable consequences. Our primary focus will be the special case of Double-Disk Dark Matter (DDDM), in which self-interactions allow the dark matter to lose enough energy to lead to dynamics similar ...

  4. GE & AE Extension Request Form, Version 7, Feb 2013, JC Program Change

    E-Print Network [OSTI]

    Escher, Christine

    GE & AE Extension Request Form, Version 7, Feb 2013, JC Program Change Pathway Today's Date to General English. How many sessions of GE do you wish to request? 1 2 3 4 (GE sessions are 5 weeks) How many GE hours do you wish to take? 21 hours 27 hours OR ____ I am a Pathway student, and I would like

  5. CTu2J.1.pdf CLEO Technical Digest OSA 2012 Light Emission in Ge Quantum Wells

    E-Print Network [OSTI]

    Miller, David A. B.

    CTu2J.1.pdf CLEO Technical Digest © OSA 2012 Light Emission in Ge Quantum Wells Edward T. Fei1 Engineering, Stanford University, Stanford, CA 94305, USA edfei@stanford.edu Abstract: We present the Ge/SiGe and electroluminescence show enhanced optical properties over bulk Ge. Further optical enhancement is observed in disk

  6. College of Engineering Partner Schools Australia Melbourne University, Melbourne GE3*

    E-Print Network [OSTI]

    Lee, Tonghun

    College of Engineering Partner Schools Australia Melbourne University, Melbourne ­ GE3* University of New South Wales, New South Wales ­ GE3* Austria Technical University of Vienna, Vienna - GE3* Chile Universidad del Bio Bio, Concepcion China Xiamen University, Xiamen ­ GE3* Denmark Aalborg University, Aalborg

  7. On the Comparison of Fisher Information of the Weibull and GE Distributions

    E-Print Network [OSTI]

    Kundu, Debasis

    On the Comparison of Fisher Information of the Weibull and GE Distributions Rameshwar D. Gupta exponen- tial (GE) and Weibull distributions for complete and Type-I censored observations. Fisher is much more than the GE distribution. We compute the total information of the Weibull and GE

  8. GE Hosts Visit by DOE to Kick Off High-Efficiency GeneratorDevelopment Program

    E-Print Network [OSTI]

    history of working with the DOE on critical energy programs. Jon Ebacher, Vice President of GE PowerGE Hosts Visit by DOE to Kick Off High-Efficiency GeneratorDevelopment Program Technology Expected of Energy (DOE) recently met with representatives of GE Power Systems and the GE Global Research Center

  9. Orange-green emission from porous Si coated with Ge films: The role of Ge-related defects

    E-Print Network [OSTI]

    Chen, Haydn H.

    Orange-green emission from porous Si coated with Ge films: The role of Ge-related defects X. L. Wua. A new orange-green PL band, centered at 2.25 eV, was observed with full-width at half-maximum of 0.1 e coated, the new PL band remains unchanged in peak energy but drops abruptly in intensity. Spectral

  10. Dark matter and EWSB naturalness in unified SUSY models

    SciTech Connect (OSTI)

    Sandick, Pearl

    2013-05-23

    The relationship between the degree of fine-tuning in Electroweak Symmetry Breaking (EWSB) and the discoverability of dark matter in current and next generation direct detection experiments is investigated in the context of two unified Supersymmetry scenarios: the Constrained Minimal Supersymmetric Standard Model (CMSSM) and models with Non-Universal Higgs Masses (NUHM). Attention is drawn to the mechanism(s) by which the relic abundance of neutralino dark matter is suppressed to cosmologically viable values. After a summary of Amsel, Freese, and Sandick (2011), results are updated to reflect current constraints, including the discovery of a new particle consistent with a Standard Model-like Higgs boson. We find that a Higgs mass of {approx} 125 GeV excludes the least fine-tuned CMSSM points in our parameter space and that remaining viable models may be difficult to probe with next generation direct dark matter searches. Relatively low fine-tuning and good direct detection prospects are still possible in NUHM scenarios.

  11. Generalised form factor dark matter in the Sun

    E-Print Network [OSTI]

    Aaron C. Vincent; Aldo Serenelli; Pat Scott

    2015-04-16

    We study the effects of energy transport in the Sun by asymmetric dark matter with momentum and velocity-dependent interactions, with an eye to solving the decade-old Solar Abundance Problem. We study effective theories where the dark matter-nucleon scattering cross-section goes as $v_{\\rm rel}^{2n}$ and $q^{2n}$ with $n = -1, 0, 1 $ or $2$, where $v_{\\rm rel}$ is the dark matter-nucleon relative velocity and $q$ is the momentum exchanged in the collision. Such cross-sections can arise generically as leading terms from the most basic nonstandard DM-quark operators. We employ a high-precision solar simulation code to study the impact on solar neutrino rates, the sound speed profile, convective zone depth, surface helium abundance and small frequency separations. We find that the majority of models that improve agreement with the observed sound speed profile and depth of the convection zone also reduce neutrino fluxes beyond the level that can be reasonably accommodated by measurement and theory errors. However, a few specific points in parameter space yield a significant overall improvement. A 3-5 GeV DM particle with $\\sigma_{SI} \\propto q^2$ is particularly appealing, yielding more than a $6\\sigma$ improvement with respect to standard solar models, while being allowed by direct detection and collider limits. We provide full analytical capture expressions for $q$- and $v_{\\rm rel}$-dependent scattering, as well as complete likelihood tables for all models.

  12. IDMS: Inert Dark Matter Model with a complex singlet

    E-Print Network [OSTI]

    Cesar Bonilla; Dorota Sokolowska; Neda Darvishi; J. Lorenzo Diaz-Cruz; Maria Krawczyk

    2015-04-13

    Within the Inert Doublet Model (IDM) there is a viable dark matter candidate. This simple model can provide a strong enough first order phase transition, which is required in order to account for the matter-antimatter asymmetry in the Universe (BAU). However, another necessary ingredient is missing, as there is no additional source of CP violation in the IDM, besides the standard CKM phase from the Standard Model. Additional CP violating phase can appear if a complex singlet of $SU(3)_C \\times SU(2)_W \\times U(1)_Y$ with a non-zero vacuum expectation value is added to the scalar sector of the IDM. We construct the scalar potential of the inert doublet plus singlet model (IDMS), assuming an exact $Z_2$ symmetry, with singlet being $Z_2$-even. To simplify the model we use a softly broken $U(1)$ symmetry, which allows a reduction of the number of free parameters in the potential. We study the masses and interactions of scalar particles for a few benchmark scenarios. Constraints from collider physics, in particular from the Higgs signal observed at LHC with $M_h\\approx 125$ GeV are discussed, as well as constraints from the dark matter experiments.

  13. Strain-induced self-assembly of Ge nanodashes, nanodumbbells, and dot chains on Si(001)

    SciTech Connect (OSTI)

    Zhang, J. J. [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany) [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany); Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); Schmidt, O. G. [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany) [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany); Center for Advancing Electronics Dresden, TU Dresden (Germany)

    2013-09-30

    We investigate the growth of self-assembled Ge nanostructures on top of embedded Ge nanowires on Si(001) substrates. Ge nanostructures, such as nanodashes, nanodumbbells, and dot chains are observed simply by tuning the growth temperature and thickness of the Si spacer between the Ge layers. The self-assembly process is governed by the surface strain fields generated by the embedded Ge nanowires and is well-described by our theoretical calculations. The catalyst-free and horizontal growth of such Ge nanostructures directly on Si(001) is attractive for investigating exotic transport properties through Si/Ge-based quantum devices.

  14. Dark matter burners

    E-Print Network [OSTI]

    Moskalenko, I V

    2006-01-01

    We show that a star orbiting close enough to an adiabatically grown supermassive black hole can capture a large number of weakly interacting massive particles (WIMPs) during its lifetime. WIMP annihilation energy release in low- to medium-mass stars is comparable with or even exceeds the luminosity of such stars due to thermonuclear burning. The excessive energy release in the stellar core may result in an evolution scenario different from what is expected for a regular star. The model thus predicts the existence of unusual stars within the central parsec of galactic nuclei. If found, such stars would provide evidence for the existence of particle dark matter. The excess luminosity of such stars attributed to WIMP "burning" can be used to infer the local WIMP matter density. A white dwarf with a highly eccentric orbit around the central black hole may exhibit variations in brightness correlated with the orbital phase. On the other hand, white dwarfs shown to lack such orbital brightness variations can be used...

  15. Condensed Matter and Magnet Science

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    helimagnets and the development of a cryogen-free apparatus for spherical neutron polarimetry." Read more... Cutting-edge condensed matter physics research, high magnetic field...

  16. Nuclear Matter and Nuclear Dynamics

    E-Print Network [OSTI]

    M Colonna

    2009-02-26

    Highlights on the recent research activity, carried out by the Italian Community involved in the "Nuclear Matter and Nuclear Dynamics" field, will be presented.

  17. Proton Delivery and Removal in [Ni(P&lt;sup>R</sup><;sub>2&lt;/sub>N&lt;sup>R&lt;sup>&lt;/sup></sup><;sub>2&lt;/sub>)<;sub>2&lt;/sub>]<;sup>2+&lt;/sup> Hydrogen Production and Oxidation Catalysts

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) by Carbon-RichProton Delivery and Removal in [Ni(P R 2 N R' 2 ) 2 ] 2+

  18. Dark Matter in Leptophilic Higgs Models After the LHC Run-I

    E-Print Network [OSTI]

    Buckley, Matthew R

    2015-01-01

    We examine the leptophilic two Higgs doublet model with fermionic dark matter, considering the range of experimental constraints on the Higgs sector. The measurements of the 125 GeV Higgs from the LHC Run-I allow us to focus on those remaining processes that may play an important role at colliders. We find that the leptophilic model allows for a much lighter Higgs than in other two-Higgs models, although discovery at the LHC will be difficult. Adding a dark matter sector motivated by supersymmetric extensions of the leptophilic model, we find the existing parameter space can accommodate constraints from direct detection and the invisible widths of the Higgs and $Z$, while also fitting the Galactic Center gamma ray excess reported by analyses of Fermi-LAT data. We also discuss the status of the fully supersymmetric version of such models, which include four Higgs doublets and a natural dark matter candidate.

  19. Dark Matter in Leptophilic Higgs Models After the LHC Run-I

    E-Print Network [OSTI]

    Matthew R. Buckley; David Feld

    2015-08-04

    We examine the leptophilic two Higgs doublet model with fermionic dark matter, considering the range of experimental constraints on the Higgs sector. The measurements of the 125 GeV Higgs from the LHC Run-I allow us to focus on those remaining processes that may play an important role at colliders. We find that the leptophilic model allows for a much lighter Higgs than in other two-Higgs models, although discovery at the LHC will be difficult. Adding a dark matter sector motivated by supersymmetric extensions of the leptophilic model, we find the existing parameter space can accommodate constraints from direct detection and the invisible widths of the Higgs and $Z$, while also fitting the Galactic Center gamma ray excess reported by analyses of Fermi-LAT data. We also discuss the status of the fully supersymmetric version of such models, which include four Higgs doublets and a natural dark matter candidate.

  20. Search for critical behavior of strongly interacting matter at the CERN Super Proton Synchrotron

    E-Print Network [OSTI]

    Gazdzicki, Marek

    2015-01-01

    History, status and plans of the search for critical behavior of strongly interacting matter created in nucleus-nucleus collisions at the CERN Super Proton Synchrotron is reviewed. In particular, it is expected that the search should answer the question whether the critical point of strongly interacting matter exists and, if it does, where it is located. First, the search strategies are presented and a short introduction is given to expected fluctuation signals and to the quantities used by experiments to detect th The most important background effects are also discussed. Second, relevant experimental results are summarized and discussed. It is intriguing that both the fluctuations of quantities integrated over the full experimental acceptance (event multiplicity and transverse momentum) as well as the bin size dependence of the second factorial moment of pion and proton multiplicities in medium-sized Si+Si collisions at 158A GeV/c suggest critical behaviour of the created matter. These results provide strong...

  1. Galactic Center gamma-ray excess and Higgs-portal Dark Matter

    E-Print Network [OSTI]

    Tanmoy Mondal; Tanushree Basak

    2015-07-07

    From astronomical observations, we know that dark matter exists and makes up $\\sim$25\\% of our Universe. Recently the study of anomalous gamma-ray emission in the regions surrounding the galactic center has drawn a lot of attention. It has been pointed out that the excess of 1-3 GeV gamma-ray in the low latitude is consistent with the emission expected from annihilating dark matter. I will discuss the Higgs-portal dark matter models which can explain these phenomena because of the presence of scalar resonance. In addition, the parameter space of these models also satisfy constraints from the LHC Higgs searches, relic abundance and direct detection experiments. The gauged $U(1)_{B-L}$ model is very well suited with the FERMI-LAT observation along with other constraints.

  2. Diffusion of dark matter in a hot and dense nuclear environment

    E-Print Network [OSTI]

    Cermeño, Marina; Silk, Joseph

    2015-01-01

    We calculate the mean free path in a hot and dense nuclear environment for a fermionic dark matter particle candidate interacting with nucleons via scalar and vector couplings. We determine the effects of density and temperature in the medium by using nuclear distribution functions to size the importance of the final state blocking. Our results show that stellar nuclear scenarios, where dark matter may be accreted, provide opacities several orders of magnitude larger than those for Standard Model neutrinos in the context of cooling of proto-neutron stars. We also show that in a diffusive approximation with couplings of Fermi's constant strength the obtained dark matter-nucleon crosss sections display the same sensitivity that upper limits constrained with collider searches in the mass region $m_\\chi \\lesssim$ 5 GeV.

  3. Dark Matter Directionality Revisited with a High Pressure Xenon Gas Detector

    E-Print Network [OSTI]

    Gopolang Mohlabeng; Kyoungchul Kong; Jin Li; Adam Para; Jonghee Yoo

    2015-11-19

    An observation of the anisotropy of dark matter interactions in a direction-sensitive detector would provide decisive evidence for the discovery of galactic dark matter. Directional information would also provide a crucial input to understanding its distribution in the local Universe. Most of the existing directional dark matter detectors utilize particle tracking methods in a low-pressure gas time projection chamber. These low pressure detectors require excessively large volumes in order to be competitive in the search for physics beyond the current limit. In order to avoid these volume limitations, we consider a novel proposal, which exploits a columnar recombination effect in a high-pressure gas time projection chamber. The ratio of scintillation to ionization signals observed in the detector carries the angular information of the particle interactions. In this paper, we investigate the sensitivity of a future directional detector focused on the proposed high-pressure Xenon gas time projection chamber. We study the prospect of detecting an anisotropy in the dark matter velocity distribution. We find that tens of events are needed to exclude an isotropic distribution of dark matter interactions at 95% confidence level in the most optimistic case with head-to-tail information. However, one needs at least 10-20 times more events without head-to-tail information for light dark matter below 50 GeV. For an intermediate mass range, we find it challenging to observe an anisotropy of the dark matter distribution. Our results also show that the directional information significantly improves precision measurements of dark matter mass and the elastic scattering cross section for a heavy dark matter.

  4. Dark matter directionality revisited with a high pressure xenon gas detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mohlabeng, Gopolang; Kong, Kyoungchul; Li, Jin; Para, Adam; Yoo, Jonghee

    2015-07-20

    An observation of the anisotropy of dark matter interactions in a direction-sensitive detector would provide decisive evidence for the discovery of galactic dark matter. Directional information would also provide a crucial input to understanding its distribution in the local Universe. Most of the existing directional dark matter detectors utilize particle tracking methods in a low-pressure gas time projection chamber. These low pressure detectors require excessively large volumes in order to be competitive in the search for physics beyond the current limit. In order to avoid these volume limitations, we consider a novel proposal, which exploits a columnar recombination effect inmore »a high-pressure gas time projection chamber. The ratio of scintillation to ionization signals observed in the detector carries the angular information of the particle interactions. In this paper, we investigate the sensitivity of a future directional detector focused on the proposed high-pressure Xenon gas time projection chamber. We study the prospect of detecting an anisotropy in the dark matter velocity distribution. We find that tens of events are needed to exclude an isotropic distribution of dark matter interactions at 95% confidence level in the most optimistic case with head-to-tail information. However, one needs at least 10-20 times more events without head-to-tail information for light dark matter below ~50 GeV. For an intermediate mass range, we find it challenging to observe an anisotropy of the dark matter distribution. Our results also show that the directional information significantly improves precision measurements of dark matter mass and the elastic scattering cross section for a heavy dark matter.« less

  5. Scalar dark matter and fermion coannihilations in the radiative seesaw model

    SciTech Connect (OSTI)

    Klasen, Michael; Yaguna, Carlos E.; Ruiz-Álvarez, José D.; Restrepo, Diego; Zapata, Oscar E-mail: carlos.yaguna@uni-muenster.de E-mail: restrepo@udea.edu.co

    2013-04-01

    By extending the Standard Model with three right-handed neutrinos (N{sub i}) and a second Higgs doublet (H{sub 2}), odd under a Z{sub 2} symmetry, it is possible to explain non-zero neutrino masses and to account for the dark matter. We consider the case where the dark matter is a scalar and study its coannihilations with the right-handed neutrinos. These coannihilations tend to increase, rather than reduce, the dark matter density and they modify in a significant way the viable parameter space of the model. In particular, they allow to satisfy the relic density constraint for dark matter masses well below 500 GeV. The dependence of the relic density on the relevant parameters of the model, such as the dark matter mass, the mass splitting, and the number of coannihilating fermions, is analyzed in detail. We also investigate, via a scan over the parameter space, the new viable regions that are obtained when coannihilations are taken into account. Notably, they feature large indirect detection rates, with (?v) reaching values of order 10{sup ?24}cm{sup 3}s{sup ?1}. Finally, we emphasize that coannihilation effects analogous to those discussed here can be used to reconcile a thermal freeze-out with a large (?v) also in other models of dark matter.

  6. The positron excess as a smoking gun for dynamical dark matter?

    SciTech Connect (OSTI)

    Dienes, Keith R.; Kumar, Jason; Thomas, Brooks

    2014-06-24

    One of the most puzzling aspects of recent data from the AMS-02 experiment is an apparent rise in the cosmic-ray positron fraction as a function of energy. This feature is observed out to energies of approximately 350 GeV. One explanation of these results interprets the extra positrons as arising from the decays of dark-matter particles. This in turn typically requires that such particles have rather heavy TeV-scale masses and not undergo simple two-body decays to leptons. In this talk, by contrast, we show that Dynamical Dark Matter (DDM) can not only match existing AMS-02 data on the positron excess, but also accomplish this feat with significantly lighter dark-matter constituents undergoing simple two-body decays to leptons. We also demonstrate that the Dynamical Dark Matter framework makes a fairly robust prediction that the positron fraction should level off and then remain roughly constant out to approximately 1 TeV, without experiencing any sharp downturns. Thus, if we interpret the positron excess in terms of decaying dark matter, the existence of a plateau in the positron fraction at energies less than 1 TeV may be taken as a “smoking gun” of Dynamical Dark Matter.

  7. TEM Study on the Evolution of Ge Nanocrystals in Si Oxide Matrix as a Function of Ge Concentration and the Si Reduction Process

    E-Print Network [OSTI]

    Chew, Han Guan

    Growth and evolution of germanium (Ge) nanocrystals embedded into a silicon oxide (SiO?) system have been studied based on the Ge content of co-sputtered Ge-SiO? films using transmission electron microscopy (TEM) and X-ray ...

  8. Dark matter burners

    E-Print Network [OSTI]

    Moskalenko, I V; Moskalenko, Igor V.; Wai, Lawrence L.

    2007-01-01

    We show that a star orbiting close enough to an adiabatically grown supermassive black hole (SMBH) can capture weakly interacting massive particles (WIMPs) at an extremely high rate. The stellar luminosity due to annihilation of captured WIMPs in the stellar core may be comparable to or even exceed the luminosity of the star due to thermonuclear burning. The model thus predicts the existence of unusual stars, essentially WIMP burners, in the vicinity of a SMBH. We find that the most efficient WIMP burners are stars with degenerate electron cores, e.g. white dwarfs (WDs); such WDs may have a very high surface temperature. If found, such stars would provide evidence for the existence of particle dark matter and can possibly be used to establish its density profile. On the other hand, the lack of such unusual stars may provide constraints on the WIMP density near the SMBH, as well as the WIMP-nucleus scattering and pair annihilation cross-sections.

  9. Dark matter burners

    E-Print Network [OSTI]

    Igor V. Moskalenko; Lawrence L. Wai

    2007-02-24

    We show that a star orbiting close enough to an adiabatically grown supermassive black hole (SMBH) can capture weakly interacting massive particles (WIMPs) at an extremely high rate. The stellar luminosity due to annihilation of captured WIMPs in the stellar core may be comparable to or even exceed the luminosity of the star due to thermonuclear burning. The model thus predicts the existence of unusual stars, essentially WIMP burners, in the vicinity of a SMBH. We find that the most efficient WIMP burners are stars with degenerate electron cores, e.g. white dwarfs (WDs); such WDs may have a very high surface temperature. If found, such stars would provide evidence for the existence of particle dark matter and can possibly be used to establish its density profile. On the other hand, the lack of such unusual stars may provide constraints on the WIMP density near the SMBH, as well as the WIMP-nucleus scattering and pair annihilation cross-sections.

  10. Energy Matters in Washington State

    E-Print Network [OSTI]

    Collins, Gary S.

    Energy Matters in Washington State Energy Matters in Washington State www.energy.wsu.edu/library/ November 2009 #12;905 Plum Street SE, Building 3 P.O. Box 43169 Olympia, Washington 98504-3169 Energy University Extension Energy Program. 905 Plum Street SE, Building 3, P.O. Box 43169, Olympia, Washington

  11. Astronomical Evidence for Dark Matter

    E-Print Network [OSTI]

    Golwala, Sunil

    dark matter (assumed non-baryonic) #12;A word about constitutes an energy density from the Friedmann Equation: (Assuming no curvature) #12;Definitions C Critical Density X X/C = 1 => flat universe, what Rotation curve: Virial Theorem: #12;Spiral Galaxies Luminous Matter ~ follows: Asymptotes to constant value

  12. dark matter dark energy inflation

    E-Print Network [OSTI]

    Hu, Wayne

    theory dark matter dark energy inflation The National Science Foundation The Kavli Foundation NSF Site Review November 28-29, 2005 #12;dark matter dark energy inflation NSF Site Visit ­ November 28 - 29, 2005The National Science Foundation The Kavli Foundation The Theoretical Web UHE cosmic rays B

  13. Dark matter on the lattice

    E-Print Network [OSTI]

    Randy Lewis

    2014-11-26

    Several collaborations have recently performed lattice calculations aimed specifically at dark matter, including work with SU(2), SU(3), SU(4) and SO(4) gauge theories to represent the dark sector. Highlights of these studies are presented here, after a reminder of how lattice calculations in QCD itself are helping with the hunt for dark matter.

  14. Charmonium mass in nuclear matter 

    E-Print Network [OSTI]

    Lee, S. H.; Ko, Che Ming.

    2003-01-01

    The mass shift of charmonium states in nuclear matter is studied in the perturbative QCD approach. The leading-order effect due to the change of gluon condensate in nuclear matter is evaluated using the leading-order QCD formula, while the higher...

  15. Warm Dark Matter via Ultra-Violet Freeze-In: Reheating Temperature and Non-Thermal Distribution for Fermionic Higgs Portal Dark Matter

    E-Print Network [OSTI]

    John McDonald

    2015-12-20

    Warm dark matter (WDM) of order keV mass may be able to resolve the disagreement between structure formation in cold dark matter simulations and observations. The detailed properties of WDM will depend upon its energy distribution, in particular how it deviates from the thermal distribution usually assumed in WDM simulations. Here we focus on WDM production via the Ultra-Violet (UV) freeze-in mechanism, for the case of fermionic Higgs portal dark matter $\\psi$ produced the portal interaction $\\overline{\\psi}\\psi H^{\\dagger}H/\\Lambda$. We show that the reheating temperature must satisfy $T_{R} \\gtrsim 0.3 $ TeV in order to account for the observed dark matter density when $m_{\\psi} \\approx 2 $ keV, where the lower bound on $T_{R}$ corresponds to the limit where the fermion mass is entirely due to electroweak symmetry breaking via the portal interaction. The corresponding bound on the interaction scale is $\\Lambda \\gtrsim 1.5 \\times 10^{10}$ GeV. We introduce a new method to simplify the computation of the non-thermal energy distribution of dark matter from freeze-in. We show that the non-thermal energy distribution from UV freeze-in is much broader and flatter than the corresponding thermal distribution.

  16. Quantum vacuum and dark matter

    E-Print Network [OSTI]

    Dragan Slavkov Hajdukovic

    2011-11-21

    Recently, the gravitational polarization of the quantum vacuum was proposed as alternative to the dark matter paradigm. In the present paper we consider four benchmark measurements: the universality of the central surface density of galaxy dark matter haloes, the cored dark matter haloes in dwarf spheroidal galaxies, the non-existence of dark disks in spiral galaxies and distribution of dark matter after collision of clusters of galaxies (the Bullet cluster is a famous example). Only some of these phenomena (but not all of them) can (in principle) be explained by the dark matter and the theories of modified gravity. However, we argue that the framework of the gravitational polarization of the quantum vacuum allows the understanding of the totality of these phenomena.

  17. Indirect search for dark matter with AMS in positrons, gamma and antiprotons channels

    E-Print Network [OSTI]

    Diego Casadei

    2006-09-04

    The Alpha Magnetic Spectrometer (AMS), to be installed on the International Space Station, will provide data on cosmic radiations in a large energy range. The main physics goals in the astroparticle domain are the antimatter and the dark matter searches. Dark matter should be composed of non baryonic weakly interacting massive particles, a good candidate being the lightest SUSY particle in R-parity conserving models. As a prototype for the AMS-02 experiment, the AMS-01 particle spectrometer was flown on the Space Shuttle Discovery in near earth orbit for a ten day mission in June 1998. The direct identification of positrons in AMS-01 was limited to energies below 3 GeV due to the vast proton background and the characteristics of the subdetectors, but the sensitivity towards higher energies (up to 40 GeV) was extended by identifying positrons through the conversion of bremsstrahlung photons. AMS-02 will greatly improve the accuracy on the positron spectrum, which will be measured up to 300 GeV, together with the antiproton and $\\gamma$-ray flux, thus providing a unique chance to measure all relevant neutralino decay channels with the same experiment.

  18. Indirect search for dark matter with AMS in positrons, gamma and antiprotons channels

    E-Print Network [OSTI]

    Casadei, D

    2007-01-01

    The Alpha Magnetic Spectrometer (AMS), to be installed on the International Space Station, will provide data on cosmic radiations in a large energy range. The main physics goals in the astroparticle domain are the antimatter and the dark matter searches. Dark matter should be composed of non baryonic weakly interacting massive particles, a good candidate being the lightest SUSY particle in R-parity conserving models. As a prototype for the AMS-02 experiment, the AMS-01 particle spectrometer was flown on the Space Shuttle Discovery in near earth orbit for a ten day mission in June 1998. The direct identification of positrons in AMS-01 was limited to energies below 3 GeV due to the vast proton background and the characteristics of the subdetectors, but the sensitivity towards higher energies (up to 40 GeV) was extended by identifying positrons through the conversion of bremsstrahlung photons. AMS-02 will greatly improve the accuracy on the positron spectrum, which will be measured up to 300 GeV, together with t...

  19. Optical nanoscopy of transient states in condensed matter

    E-Print Network [OSTI]

    Kuschewski, Frederik; Green, Bert; Bauer, Christian; Gensch, Michael; Eng, Lukas M

    2015-01-01

    Recently, the fundamental and nanoscale understanding of complex phenomena in materials research and the life sciences, witnessed considerable progress. However, elucidating the underlying mechanisms, governed by entangled degrees of freedom such as lattice, spin, orbit, and charge for solids or conformation, electric potentials, and ligands for proteins, has remained challenging. Techniques that allow for distinguishing between different contributions to these processes are hence urgently required. In this paper we demonstrate the application of scattering-type scanning near-field optical microscopy (s-SNOM) as a novel type of nano-probe for tracking transient states of matter. We introduce a sideband-demodulation technique that allows for probing exclusively the stimuli-induced change of near-field optical properties. We exemplify this development by inspecting the decay of an electron-hole plasma generated in SiGe thin films through near-infrared laser pulses. Our approach can universally be applied to opt...

  20. Integrating in the Higgs Portal to Fermion Dark Matter

    E-Print Network [OSTI]

    Ayres Freitas; Susanne Westhoff; Jure Zupan

    2015-06-23

    Fermion dark matter (DM) interacting with the standard model through a Higgs portal requires non-renormalizable operators, signaling the presence of new mediator states at the electroweak scale. Collider signatures that involve the mediators are a powerful tool to experimentally probe the Higgs portal interactions, providing complementary information to strong constraints set by direct DM detection searches. Indirect detection experiments are less sensitive to this scenario. We investigate the collider reach for the mediators using three minimal renormalizable models as examples, and requiring the fermion DM to be a thermal relic. The Large Hadron Collider in its high-energy, high-luminosity phase can probe most scenarios if DM is lighter than about 200 GeV. Beyond this scale, future high-energy experiments such as an electron-positron collider or a 100-TeV proton-proton collider, combined with future direct detection experiments, are indispensable to conclusively test these models.

  1. Light dark matter in the light of CRESST-II

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kopp, Joachim; Schwetz, Thomas; Zupan, Jure

    2012-03-01

    Recently the CRESST collaboration has published the long anticipated results of their direct Dark Matter (DM) detection experiment with a CaWO4 target. The number of observed events exceeds known backgrounds at more than 4? significance, and this excess could potentially be due to DM scattering. We confront this interpretation with null results from other direct detection experiments for a number of theoretical models, and find that consistency is achieved in non-minimal models such as inelastic DM and isospin-violating DM. In both cases mild tension with constraints remain. The CRESST data can, however, not be reconciled with the null results andmore »with the positive signals from DAMA and CoGeNT simultaneously in any of the models we study.« less

  2. The 6 GeV TMD Program at Jefferson Lab

    SciTech Connect (OSTI)

    Puckett, Andrew J.

    2015-01-01

    The study of the transverse momentum dependent parton distributions (TMDs) of the nucleon in semi-inclusive deep-inelastic scattering (SIDIS) has emerged as one of the major physics motivations driving the experimental program using the upgraded 11 GeV electron beam at Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF). The accelerator construction phase of the CEBAF upgrade is essentially complete and commissioning of the accelerator has begun as of April, 2014. As the new era of CEBAF operations begins, it is appropriate to review the body of published and forthcoming results on TMDs from the 6 GeV era of CEBAF operations, discuss what has been learned, and discuss the key challenges and opportunities for the 11 GeV SIDIS program of CEBAF.

  3. Effect of mixed Ge/Si cross-linking on the physical properties of amorphous Ge-Si-Te networks

    SciTech Connect (OSTI)

    Gunasekera, K.; Boolchand, P. [School of Electronics and Computing Systems, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, Ohio 45221-0030 (United States); Micoulaut, M., E-mail: mmi@lptl.jussieu.fr [Laboratoire de Physique Théorique de la Matière Condensée, Université Pierre et Marie Curie, 4 Place Jussieu, F-75252 Paris Cedex 05 (France)

    2014-04-28

    Amorphous Ge{sub x}Si{sub x}Te{sub 1?2x} glasses are studied as a function of composition by a combination of experimental and theoretical methods, allowing for a full description of the network structure in relationship with physico-chemical properties. Calorimetric and thermal measurements reveal that such glasses display an anomalous behavior across a range of compositions x{sub c1}=7.5% and Ge, Si) are increased. The structural manifestation of these anomalies is understood from ?{sup 119}Sn Mössbauer spectroscopy and First Principles Molecular Dynamics at selected compositions (Ge{sub 20}Te{sub 80}, Si{sub 20}Te{sub 80}, and Ge{sub 10}Si{sub 10}Te{sub 80}). The numerical models reveal the quite different roles played by the modifier or network cross-linker Ge or Si atoms, Si being more tetrahedral in sp{sup 3} geometry, whereas Mössbauer spectroscopy shows that the nature of chemical bonding is dramatically changed around x??8%. The precise evolution of the local structure and chemical bonding ultimately allows understanding the origin of the intermediate phase in these complex tellurides.

  4. Freeze-In Dark Matter with Displaced Signatures at Colliders

    E-Print Network [OSTI]

    Raymond T. Co; Francesco D'Eramo; Lawrence J. Hall; Duccio Pappadopulo

    2015-06-24

    Dark matter, $X$, may be generated by new physics at the TeV scale during an early matter-dominated (MD) era that ends at temperature $T_R \\ll {\\rm TeV}$. Compared to the conventional radiation-dominated (RD) results, yields from both Freeze-Out and Freeze-In processes are greatly suppressed by dilution from entropy production, making Freeze-Out less plausible while allowing successful Freeze-In with a much larger coupling strength. Freeze-In is typically dominated by the decay of a particle $B$ of the thermal bath, $B \\rightarrow X$. For a large fraction of the relevant cosmological parameter space, the decay rate required to produce the observed dark matter abundance leads to displaced signals at LHC and future colliders, for any $m_X$ in the range ${\\rm keV} < m_X < m_B$ and for values of $m_B$ accessible to these colliders. This result applies whether the early MD era arises after conventional inflation, when $T_R$ is the usual reheat temperature, or is a generic MD era with an alternative origin. In the former case, if $m_X$ is sufficiently large to be measured from kinematics, the reheat temperature $T_R$ can be extracted. Our result is independent of the particular particle physics implementation of $B \\rightarrow X$, and can occur via any operator of dimension less than 8 (4) for a post-inflation (general MD) cosmology. An interesting example is provided by DFS axion theories with TeV-scale supersymmetry and axino dark matter of mass GeV to TeV, which is typically overproduced in a conventional RD cosmology. If $B$ is the higgsino, $\\tilde h$, Higgs, W and Z particles appear at the displaced decays, $\\tilde h \\rightarrow h \\tilde a, Z \\tilde a$ and $\\tilde h^\\pm \\rightarrow W^\\pm \\tilde a$. The scale of axion physics, $f$, is predicted to be in the range $(3\\times10^8 - 10^{12})$ GeV and, over much of this range, can be extracted from the decay length.

  5. Nuclear-matter--quark-matter phase diagram with strangeness

    SciTech Connect (OSTI)

    Barz, H. W.; Friman, B. L.; Knoll, J.; Schulz, H.

    1989-07-01

    A phenomenological equation of state of strongly interacting matter, including strange degrees of freedom, is presented. It is shown that the hyperon and kaon interactions must be included, in order to obtain a reasonable description of the deconfinement transition at high baryon densities. The consequences of kaon condensation on the nuclear-matter--quark-matter phase diagram are explored. The relative particle abundances obtained in an isentropic expansion of a blob of quark-gluon plasma are presented for different initial conditions. Implications for ultrarelativistic heavy-ion collisions are briefly discussed.

  6. The Conformal Universe III: Basic Mechanisms of Matter Generation

    E-Print Network [OSTI]

    Renato Nobili

    2014-12-22

    This is the last of three papers on Conformal General Relativity (CGR), which describes inflation as a process primed by the spontaneous breakdown of a conformal-symmetric instable vacuum and the big bang as a sudden transfer of energy from geometry to matter. This process is driven by the interaction of a ghost scalar field $\\sigma$, called the {\\em dilation field}, with a scalar field $\\varphi$ behaving as a Higgs field of varying mass. Inflation ends when the interaction potential vanishes and $\\sigma,\\varphi$ amplitudes converge to their expectation values in a stable vacuum. Explicit solutions of $\\sigma, \\varphi$ dynamics in the semiclassical approximation are exemplified by numerical simulations. In order that the theory may survive quantization, the perfect vanishing of the total zero-point energy density of all involved fields must be postulated, which is equivalent to extending the correspondence principle of Bohr to quantum field theory. Since inflation actually is an adiabatic thermodynamic process, the temperature $T_B\\simeq 142$\\,GeV and the effective degeneracy $g_{*s}(T_B)\\simeq 0.887$ of Higgs-boson entropy at big bang are easily found. The application of entropy-conservation property then results in striking predictions. In particular, given the Higg-boson mass $\\mu_H\\simeq 126.5$ GeV and self-coupling constant $\\lambda\\simeq 0.132$, and the temperature $T_{BK}= 2.35\\times 10^{-13}$ and effective entropy degeneracy $g_{*s}(T_{BK})\\simeq 3.91$ of the current cosmic-background radiation, the cosmological constant $\\rho_{\\hbox{vac}}\\simeq 6.91\\times 10^{-47}$GeV$^4$ and expansion factor across inflation $F\\simeq 1.32\\times 10^{27}$ are predicted.

  7. C incorporation in epitaxial Ge1yCy layers grown on Ge,,001...: An ab initio study D. Gall, J. D'Arcy-Gall, and J. E. Greene

    E-Print Network [OSTI]

    Gall, Daniel

    C incorporation in epitaxial Ge1ÀyCy layers grown on Ge,,001...: An ab initio study D. Gall, J. D lattice site configurations in fully coherent Ge1 yCy layers grown on Ge 001 . Calculations using strained configuration involving only one C atom per configura- tion. The bond-centered interstitial and the Ge-C split

  8. Constraints on dark matter annihilation from CMB observations before Planck

    SciTech Connect (OSTI)

    Lopez-Honorez, Laura [Theoretische Natuurkunde, Vrije Universiteit Brussel and The International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Mena, Olga; Palomares-Ruiz, Sergio; Vincent, Aaron C., E-mail: llopezho@vub.ac.be, E-mail: omena@ific.uv.es, E-mail: sergio.palomares.ruiz@ist.utl.pt, E-mail: vincent@ific.uv.es [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain)

    2013-07-01

    We compute the bounds on the dark matter (DM) annihilation cross section using the most recent Cosmic Microwave Background measurements from WMAP9, SPT'11 and ACT'10. We consider DM with mass in the MeV–TeV range annihilating 100% into either an e{sup +}e{sup ?} or a ?{sup +}?{sup ?} pair. We consider a realistic energy deposition model, which includes the dependence on the redshift, DM mass and annihilation channel. We exclude the canonical thermal relic abundance cross section ((?v) = 3 × 10{sup ?26}cm{sup 3}s{sup ?1}) for DM masses below 30 GeV and 15 GeV for the e{sup +}e{sup ?} and ?{sup +}?{sup ?} channels, respectively. A priori, DM annihilating in halos could also modify the reionization history of the Universe at late times. We implement a realistic halo model taken from results of state-of-the-art N-body simulations and consider a mixed reionization mechanism, consisting on reionization from DM as well as from first stars. We find that the constraints on DM annihilation remain unchanged, even when large uncertainties on the halo model parameters are considered.

  9. Field-induced quantum criticality in YbAgGe

    SciTech Connect (OSTI)

    Bud'ko, S.; Canfield, P.

    2008-01-01

    YbAgGe is one of the very few stoichiometric, Yb-based, heavy fermion materials that exhibit field-induced quantum criticality. We will present an overview of thermodynamic and transport measurements in YbAgGe single crystals. Moderate magnetic field (45-90 kOe, depending on orientation) suppresses long range magnetic order, giving rise to non-Fermi-liquid behavior followed at higher field by a crossover to a heavy Fermi-liquid. Given the more accessible temperature and field scales, a non-Fermi liquid region rather than point for T {yields} 0 K may be detected.

  10. A Search for dark matter in events with one jet and missing transverse energy in $p\\bar{p}$ collisions at $\\sqrt{s} = 1.96$ TeV

    SciTech Connect (OSTI)

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; /Dubna, JINR /Texas A-M

    2012-03-01

    We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp collisions at {radical}s = 1.96 TeV corresponding to an integrated luminosity of 6.7 fb{sup -1} recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction below a dark matter candidate mass of 5 GeV/c{sup 2}, and on spin-dependent interactions up to masses of 200 GeV/c{sup 2}.

  11. Hypothetical Dark Matter/Axion rockets: What can be said about Dark Matter in terms of space physics propulsion

    SciTech Connect (OSTI)

    Beckwith, Andrew [APS/Fermi contractor Aurora, Illinois 60502 630-840-2201 (United States)

    2009-03-16

    This paper discusses dark matter (DM) particle candidates from non-supersymmetry (SUSY) processes and explores how a DM candidate particle in the 100-400 GeV range could be created. Thrust from DM particles is also proposed for Photon rocket and Axion rockets. It would use a magnetic field to convert DM particles to near photonlike particles in a chamber to create thrust from the discharge of the near-photon-like particles. The presence of DM particles would suggest that thrust from the emerging near-photon-like particle would be greater than with conventional photon rockets. This amplifies and improves on an 'axion rocket ramjet' for interstellar travel. It is assumed that the same methodology used in an axion ramjet could be used with DM, with perhaps greater thrust/power conversion efficiencies.

  12. Laser Driven Dynamic Loading of Condensed Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Laser Driven Dynamic Loading of Condensed Matter Laser Driven Dynamic Loading of Condensed Matter Advanced diagnostics of experiments covering many orders of magnitude in strain...

  13. MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; SOLID STATE...

    Office of Scientific and Technical Information (OSTI)

    Open problems in condensed matter physics, 1987 Falicov, L.M. 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; SOLID STATE PHYSICS; RESEARCH PROGRAMS;...

  14. Ultrafast Spectroscopy of Warm Dense Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of planet formation and structures as well as the evolution of an imploding inertial fusion capsule depends on our understanding of matter in the complex warm dense matter...

  15. Direct band gap optical emission from Ge islands grown on relaxed Si{sub 0.5}Ge{sub 0.5}/Si (100) substrate

    SciTech Connect (OSTI)

    Aluguri, R.; Manna, S.; Ray, S. K., E-mail: physkr@phy.iitkgp.ernet.in [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

    2014-01-07

    Strained Ge islands have been grown on fully relaxed Si{sub 0.5}Ge{sub 0.5} substrate by pulsed laser ablation technique. The formation of strained Ge islands has been found for film with higher thickness following Stranski–Krastanov growth mechanism. The variation of strain with changing Ge layer thickness has been analyzed using Raman spectroscopy and high-resolution X-ray diffraction techniques. X-ray photoelectron spectra have shown the absence of any Si-Ge intermixing and oxidation of Ge films. A strong no-phonon photoluminescence emission from Ge islands has been observed, showing the superior optical characteristics of the islands grown on relaxed substrate.

  16. Radio observations of the Galactic Centre and the Coma cluster as a probe of light dark matter self-annihilations and decay

    E-Print Network [OSTI]

    Celine Boehm; Joseph Silk; Torsten Ensslin

    2010-09-30

    We update our earlier calculations of gamma ray and radio observational constraints on annihilations of dark matter particles lighter than 10 GeV. We predict the synchrotron spectrum as well as the morphology of the radio emission associated with light decaying and annihilating dark matter candidates in both the Coma cluster and the Galactic Centre. Our new results basically confirm our previous findings: synchrotron emission in the very inner part of the Milky Way constrains or even excludes dark matter candidates if the magnetic field is larger than 50 micro Gauss. In fact, our results suggest that light annihilating candidates must have a S-wave suppressed pair annihilation cross section into electrons (or the branching ratio into electron positron must be small). If dark matter is decaying, it must have a life time that is larger than t = 3. 10^{25} s. Therefore, radio emission should always be considered when one proposes a "light" dark matter candidate.

  17. q-deformed statistics and the role of a light fermionic dark matter in the supernovae SN1987A cooling

    E-Print Network [OSTI]

    Atanu Guha; Selvaganapathy. J; Prasanta Kumar Das

    2015-09-19

    Light dark matter($\\simeq 1-30~\\rm{MeV}$) particles, pair produced in electron-positron annihilation $ e^-e^+ \\stackrel{\\gamma}{\\longrightarrow} \\chi \\bar{\\chi}$ inside the core of the supernovae, can take away the energy released in the supernovae SN1987A explosion. Using the Raffelt's criterion on the emissivity rate of energy loss for any new channel $\\dot{\\varepsilon}(e^+ e^- \\to \\chi \\overline{\\chi}) \\le 10^{19}~{erg~g^{-1}s^{-1}}$ and working within the formalism of $q$-deformed statistics, we obtain a lower bound on the scale $\\Lambda$ of the dark matter effective theory. As the deformation parameter $q$ varies from $1.01$ to $1.10$, we find that the bound on $\\Lambda$ changes from $3.4\\times 10^6~\\rm{GeV}$ to $2.5\\times 10^7~\\rm{GeV}$ for a light dark matter of mass $m_\\chi = 30~\\rm{MeV}$. For $q=1$ (the undeformed scenario where fermions and bosons obey the normal Fermi-Dirac and Bose-Einstein statistics) we find $\\Lambda = 2.5\\times 10^6~\\rm{GeV}$ for $m_\\chi = 30~\\rm{MeV}$.

  18. q-deformed statistics and the role of a light fermionic dark matter in the supernovae SN1987A cooling

    E-Print Network [OSTI]

    Guha, Atanu; Das, Prasanta Kumar

    2015-01-01

    Light dark matter($\\simeq 1-30~\\rm{MeV}$) particles, pair produced in electron-positron annihilation $ e^-e^+ \\stackrel{\\gamma}{\\longrightarrow} \\chi \\bar{\\chi}$ inside the core of the supernovae, can take away the energy released in the supernovae SN1987A explosion. Using the Raffelt's criterion on the emissivity rate of energy loss for any new channel $\\dot{\\varepsilon}(e^+ e^- \\to \\chi \\overline{\\chi}) \\le 10^{19}~{erg~g^{-1}s^{-1}}$ and working within the formalism of $q$-deformed statistics, we obtain a lower bound on the scale $\\Lambda$ of the dark matter effective theory. As the deformation parameter $q$ varies from $1.01$ to $1.10$, we find that the bound on $\\Lambda$ changes from $3.4\\times 10^6~\\rm{GeV}$ to $2.5\\times 10^7~\\rm{GeV}$ for a light dark matter of mass $m_\\chi = 30~\\rm{MeV}$. For $q=1$ (the undeformed scenario where fermions and bosons obey the normal Fermi-Dirac and Bose-Einstein statistics) we find $\\Lambda = 2.5\\times 10^6~\\rm{GeV}$ for $m_\\chi = 30~\\rm{MeV}$.

  19. Giant Piezoelectricity in Monolayer Group IV Monochalcogenides: SnSe, SnS, GeSe and GeS

    E-Print Network [OSTI]

    Fei, Ruixiang; Li, Ju; Yang, Li

    2015-01-01

    We predict enormous piezoelectric effects in intrinsic monolayer group IV monochalcogenides (MX, M=Sn or Ge, X=Se or S), including SnSe, SnS, GeSe and GeS. Using first-principle simulations based on the modern theory of polarization, we find that their characteristic piezoelectric coefficients are about two orders of magnitude larger than those of other 2D materials, such as MoS2 and GaSe, and bulk quartz and AlN which are widely used in industry. This enhancement is a result of the unique "puckered" D2h symmetry and weaker chemical bonds of monolayer group IV monochalcogenides. Given the achieved experimental advances in fabrication of monolayers, their flexible character and ability to withstand enormous strain, these 2D structures with giant piezoelectric effects may be promising for a broad range of applications, such as nano-sized sensors, piezotronics, and energy harvesting in portable electronic devices.

  20. INFLUENCE OF SUBSTRATE OFF-CUT ON THE DEFECT STRUCTURE IN RELAXED GRADED Si-Ge/Si LAYERS

    E-Print Network [OSTI]

    INFLUENCE OF SUBSTRATE OFF-CUT ON THE DEFECT STRUCTURE IN RELAXED GRADED Si-Ge/Si LAYERS SRIKANTH B and Engineering, University of California, Los Angeles, CA 90095. ABSTRACT Relaxed graded Si-Ge/Si layers can of these applications requires a different final Ge concentration in the graded Si-Ge layer. With increasing Ge content

  1. GE & AE Extension Request Form, Version 11, Feb 2013, JC Program Change General English or Academic English

    E-Print Network [OSTI]

    Escher, Christine

    GE & AE Extension Request Form, Version 11, Feb 2013, JC Program Change ­ General English of GE do you wish to request? 1 2 3 4 (GE sessions are 5 weeks) How many GE hours do you wish to take ______________________________________________ Date _________________ #12;GE & AE Extension Request Form, Version 11, Feb 2013, JC Please submit

  2. Casting Light on Dark Matter

    E-Print Network [OSTI]

    John Ellis

    2011-06-15

    The prospects for detecting a candidate supersymmetric dark matter particle at the LHC are reviewed, and compared with the prospects for direct and indirect searches for astrophysical dark matter. The discussion is based on a frequentist analysis of the preferred regions of the Minimal supersymmetric extension of the Standard Model with universal soft supersymmetry breaking (the CMSSM). LHC searches may have good chances to observe supersymmetry in the near future - and so may direct searches for astrophysical dark matter particles, whereas indirect searches may require greater sensitivity, at least within the CMSSM.

  3. The Unification and Cogeneration of Dark Matter and Baryonic Matter

    E-Print Network [OSTI]

    S. M. Barr

    2011-09-18

    In grand unified theories with gauge groups larger than SU(5), the multiplets that contain the known quarks and leptons also contain fermions that are singlets under the Standard Model gauge group. Some of these could be the dark matter of the universe. Grand unified theories can also have accidental U(1) global symmetries (analogous to B-L in minimal SU(5)) that can stabilize dark matter. These ideas are illustrated in an SU(6) model.

  4. The Unification and Cogeneration of Dark Matter and Baryonic Matter

    E-Print Network [OSTI]

    Barr, S M

    2011-01-01

    In grand unified theories with gauge groups larger than SU(5), the multiplets that contain the known quarks and leptons also contain fermions that are singlets under the Standard Model gauge group. Some of these could be the dark matter of the universe. Grand unified theories can also have accidental U(1) global symmetries (analogous to B-L in minimal SU(5)) that can stabilize dark matter. These ideas are illustrated in an SU(6) model.

  5. Probing Dark Matter Self-Interaction in the Sun with IceCube-PINGU

    E-Print Network [OSTI]

    Chian-Shu Chen; Fei-Fan Lee; Guey-Lin Lin; Yen-Hsun Lin

    2014-11-20

    We study the capture, annihilation and evaporation of dark matter (DM) inside the Sun. It has been shown that the DM self-interaction can increase the DM number inside the Sun. We demonstrate that this enhancement becomes more significant in the regime of small DM mass, given a fixed DM self-interaction cross section. This leads to the enhancement of neutrino flux from DM annihilation. On the other hand, for DM mass as low as a few GeVs, not only the DM-nuclei scatterings can cause the DM evaporation, DM self-interaction also provides non-negligible contributions to this effect. Consequently, the critical mass for DM evaporation (typically 3 $\\sim$ 4 GeV without the DM self-interaction) can be slightly increased. We discuss the prospect of detecting DM self-interaction in IceCube-PINGU using the annihilation channels $\\chi\\chi \\rightarrow \\tau^{+}\\tau^{-}, \

  6. keV Warm Dark Matter via the Supersymmetric Higgs Portal

    E-Print Network [OSTI]

    John McDonald; Narendra Sahu

    2009-05-14

    Warm dark matter (WDM) may resolve the possible conflict between observed galaxy halos and the halos produced in cold dark matter (CDM) simulations. Here we present an extension of MSSM to include WDM by adding a gauge singlet fermion, \\bar{\\chi}, with a portal-like coupling to the MSSM Higgs doublets. This model has the property that the dark matter is {\\it necessarily warm}. In the case where M_{\\bar{\\chi}} is mainly due to electroweak symmetry breaking, the \\bar{\\chi} mass is completely determined by its relic density and the reheating temperature, T_R. For 10^2 GeV < T_{R} < 10^{5} GeV$, the range allowed by \\bar{chi} production via thermal Higgs annihilation, the \\bar{\\chi} mass is in the range 0.3-4 keV, precisely the range required for WDM. The primordial phase-space density, Q, can directly account for that observed in dwarf spheroidal galaxies, Q \\approx 5 x 10^{6}(eV/cm^3)/(km/s)^3,, when the reheating temperature is in the range T_R \\approx 10-100 TeV, in which case M_{\\bar{\\chi}} \\approx 0.45 keV. The free-streaming length is in the range 0.3-4 Mpc, which can be small enough to alleviate the problems of overproduction of galaxy substructure and low angular momentum of CDM simulations.

  7. Inhibitive formation of nanocavities by introduction of Si atoms in Ge nanocrystals produced by ion implantation

    SciTech Connect (OSTI)

    Cai, R. S.; Shang, L.; Liu, X. H.; Zhang, Y. J. [The Cultivation Base for State Key Laboratory, Qingdao University, No. 308 Ningxia Road, Qingdao 266071 (China); Wang, Y. Q., E-mail: yqwang@qdu.edu.cn, E-mail: barba@emt.inrs.ca [The Cultivation Base for State Key Laboratory, Qingdao University, No. 308 Ningxia Road, Qingdao 266071 (China); College of Physics Science, Qingdao University, No. 308 Ningxia Road, Qingdao 266071 (China); Ross, G. G.; Barba, D., E-mail: yqwang@qdu.edu.cn, E-mail: barba@emt.inrs.ca [INRS-Énergie, Matériaux et Télécommunications, 1650 boulevard Lionel-Boulet, Varennes Québec J3X 1S2 (Canada)

    2014-05-28

    Germanium nanocrystals (Ge-nc) were successfully synthesized by co-implantation of Si and Ge ions into a SiO{sub 2} film thermally grown on (100) Si substrate and fused silica (pure SiO{sub 2}), respectively, followed by subsequent annealing at 1150?°C for 1?h. Transmission electron microscopy (TEM) examinations show that nanocavities only exist in the fused silica sample but not in the SiO{sub 2} film on a Si substrate. From the analysis of the high-resolution TEM images and electron energy-loss spectroscopy spectra, it is revealed that the absence of nanocavities in the SiO{sub 2} film/Si substrate is attributed to the presence of Si atoms inside the formed Ge-nc. Because the energy of Si-Ge bonds (301?kJ·mol{sup ?1}) are greater than that of Ge-Ge bonds (264?kJ·mol{sup ?1}), the introduction of the Si-Ge bonds inside the Ge-nc can inhibit the diffusion of Ge from the Ge-nc during the annealing process. However, for the fused silica sample, no crystalline Si-Ge bonds are detected within the Ge-nc, where strong Ge outdiffusion effects produce a great number of nanocavities. Our results can shed light on the formation mechanism of nanocavities and provide a good way to avoid nanocavities during the process of ion implantation.

  8. Tropical cyclone energy dispersion under vertical shears Xuyang Ge,1

    E-Print Network [OSTI]

    Li, Tim

    Tropical cyclone energy dispersion under vertical shears Xuyang Ge,1 Tim Li,1,2 and Xiaqiong Zhou1] Tropical cyclone Rossby wave energy dispersion under easterly and westerly vertical shears is investigated, and X. Zhou (2007), Tropical cyclone energy dispersion under vertical shears, Geophys. Res. Lett., 34, L

  9. The JLAB 12 GeV Energy Upgrade of CEBAF

    SciTech Connect (OSTI)

    Harwood, Leigh H.

    2013-12-01

    This presentation should describe the progress of the 12GeV Upgrade of CEBAF at Jefferson Lab. The status of the upgrade should be presented as well as details on the construction, procurement, installation and commissioning of the magnet and SRF components of the upgrade.

  10. Demand Response Performance of GE Hybrid Heat Pump Water Heater

    SciTech Connect (OSTI)

    Widder, Sarah H.; Parker, Graham B.; Petersen, Joseph M.; Baechler, Michael C.

    2013-07-01

    This report describes a project to evaluate and document the DR performance of HPWH as compared to ERWH for two primary types of DR events: peak curtailments and balancing reserves. The experiments were conducted with GE second-generation “Brillion”-enabled GeoSpring hybrid water heaters in the PNNL Lab Homes, with one GE GeoSpring water heater operating in “Standard” electric resistance mode to represent the baseline and one GE GeoSpring water heater operating in “Heat Pump” mode to provide the comparison to heat pump-only demand response. It is expected that “Hybrid” DR performance, which would engage both the heat pump and electric elements, could be interpolated from these two experimental extremes. Signals were sent simultaneously to the two water heaters in the side-by-side PNNL Lab Homes under highly controlled, simulated occupancy conditions. This report presents the results of the evaluation, which documents the demand-response capability of the GE GeoSpring HPWH for peak load reduction and regulation services. The sections describe the experimental protocol and test apparatus used to collect data, present the baselining procedure, discuss the results of the simulated DR events for the HPWH and ERWH, and synthesize key conclusions based on the collected data.

  11. Physical Protection of Classified Matter

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1988-02-03

    The order establishes policy and objectives for physical protection of classified matter. This directive does not cancel another directive. Chg 1, 7-30-93. Canceled by 5632.1C.

  12. Lorentz-violating dark matter 

    E-Print Network [OSTI]

    Mondragon, Antonio Richard

    2009-05-15

    was originally motivated by an unconventional fundamental theory, but which in this dissertation is defined as matter which has a nonzero minimum velocity. Furthermore, the present investigation evolved into the broader goal of exploring the properties of Lorentz...

  13. Energy Matters: Our Energy Independence

    Office of Energy Efficiency and Renewable Energy (EERE)

    In this installment of the livechat series "Energy Matters," Dr. Arun Majumdar takes questions from the public about the investments we're making today that will move us off of foreign oil and...

  14. Measurement of photons via conversion pairs in \\sqrt{s_{NN}} = 200 GeV Au+Au collisions with the PHENIX experiment at RHIC

    E-Print Network [OSTI]

    Torsten Dahms; for the PHENIX collaboration

    2006-08-04

    Thermal photons can provide information on the temperature of the new state of matter created at RHIC. In the p_T region of 1--3 GeV/c thermal photons are expected to be the dominant direct photon source. Therefore, a possible excess compared to a pure decay photon signal due to a thermal photon contribution should be seen in the double ratio (\\gamma/\\gamma(\\pi^{0}))_{Measured}/(\\gamma/\\gamma(\\pi^{0}))_{Simulated}, if sufficient accuracy can be reached. We present a method to reconstruct direct photons by measuring e^{+}e^{-}--pairs from external photon conversions.

  15. Measurement of photons via conversion pairs in Au+Au collisions at sqrt(s_NN) = 200 GeV with the PHENIX experiment at RHIC

    E-Print Network [OSTI]

    Torsten Dahms; for the PHENIX Collaboration

    2007-11-26

    Thermal photons can provide information on the temperature of the new state of matter created at RHIC. In the p_T region of 1--3 GeV/c thermal photons are expected to be the dominant direct photon source. Therefore, a possible excess compared to a pure decay photon signal due to a thermal photon contribution should be seen in the double ratio (gamma/gamma(pi^0))_{Measured}/(gamma/gamma(pi^0))_{Simulated}, if sufficient accuracy can be reached. We present a method to reconstruct direct photons by measuring e^+e^- pairs from external photon conversions.

  16. Thermal conductivity of the quark matter for the SU(2) light-flavor sector

    E-Print Network [OSTI]

    Seung-il Nam

    2015-03-04

    We investigate the thermal conductivity ($\\kappa$) of the quark matter at finite quark chemical potential $(\\mu)$ and temperature $(T)$, employing the Green-Kubo formula, for the SU(2) light-flavor sector with the finite current-quark mass $m=5$ MeV. As a theoretical framework, we construct an effective thermodynamic potential from the $(\\mu,T)$-modified liquid-instanton model (mLIM). Note that all the relevant model parameters are designated as functions of $T$, using the trivial-holonomy caloron solution. By solving the self-consistent equation of mLIM, we acquire the constituent-quark mass $M_0$ as a function of $T$ and $\\mu$, satisfying the universal-class patterns of the chiral phase transition. From the numerical results for $\\kappa$, we observe that there emerges a peak at $\\mu\\approx200$ MeV for the low-$T$ region, i.e. $T\\lesssim100$ MeV. As $T$ increase over $T\\approx100$ MeV, the curve for $\\kappa$ is almost saturated as a function of $T$ in the order of $\\sim10^{-1}\\,\\mathrm{GeV}^2$, and grows with respect to $\\mu$ smoothly. At the normal nuclear-matter density $\\rho_0=0.17\\,\\mathrm{fm}^{-3}$, $\\kappa$ shows its maximum $6.22\\,\\mathrm{GeV}^2$ at $T\\approx10$ MeV, then decreases exponentially down to $\\kappa\\approx0.2\\,\\mathrm{GeV}^2$. We also compute the ratio of $\\kappa$ and the entropy density, i.e. $\\kappa/s$ as a function of $(\\mu,T)$ which is a monotonically decreasing function for a wide range of $T$, then approaches a lower bound at very high $T$: $\\kappa/s_\\mathrm{min}\\gtrsim0.3\\,\\mathrm{GeV}^{-1}$ in the vicinity of $\\mu=0$.

  17. Two Emission Mechanisms in the Fermi Bubbles: A Possible Signal of Annihilating Dark Matter

    SciTech Connect (OSTI)

    Hooper, Dan; Slatyer, Tracy R.

    2013-09-01

    We study the variation of the spectrum of the Fermi Bubbles with Galactic latitude. Far from the Galactic plane (|b| > 30 degrees), the observed gamma-ray emission is nearly invariant with latitude, and is consistent with arising from inverse Compton scattering of the interstellar radiation field by cosmic-ray electrons with an approximately power-law spectrum. The same electrons in the presence of microgauss-scale magnetic fields can also generate the the observed microwave "haze". At lower latitudes (b < 20 degrees), in contrast, the spectrum of the emission correlated with the Bubbles possesses a pronounced spectral feature peaking at 1-4 GeV (in E^2 dN/dE) which cannot be generated by any realistic spectrum of electrons. Instead, we conclude that a second (non-inverse-Compton) emission mechanism must be responsible for the bulk of the low-energy, low-latitude emission. This second component is spectrally similar to the excess GeV emission previously reported from the Galactic Center (GC), and also appears spatially consistent with a luminosity per volume falling approximately as r^-2.4, where r is the distance from the GC. We argue that the spectral feature visible in the low-latitude Bubbles is the extended counterpart of the GC excess, now detected out to at least 2-3 kpc from the GC. The spectrum and angular distribution of the signal is consistent with that predicted from ~10 GeV dark matter particles annihilating to leptons, or from ~50 GeV dark matter particles annihilating to quarks, following a distribution similar to the canonical Navarro-Frenk-White (NFW) profile. We also consider millisecond pulsars as a possible astrophysical explanation for the signal, as observed millisecond pulsars possess a spectral cutoff at approximately the required energy. Any such scenario would require a large population of unresolved millisecond pulsars extending at least 2-3 kpc from the GC.

  18. Strongly interacting parton matter equilibration

    SciTech Connect (OSTI)

    Ozvenchuk, V.; Linnyk, O.; Bratkovskaya, E.; Gorenstein, M.; Cassing, W.

    2012-07-15

    We study the kinetic and chemical equilibration in 'infinite' parton matter within the Parton-Hadron-String Dynamics transport approach. The 'infinite' matter is simulated within a cubic box with periodic boundary conditions initialized at different energy densities. Particle abundances, kinetic energy distributions, and the detailed balance of the off-shell quarks and gluons in the strongly-interacting quarkgluon plasma are addressed and discussed.

  19. Dark Matter Triggers of Supernovae

    E-Print Network [OSTI]

    Peter W. Graham; Surjeet Rajendran; Jaime Varela

    2015-05-17

    The transit of primordial black holes through a white dwarf causes localized heating around the trajectory of the black hole through dynamical friction. For sufficiently massive black holes, this heat can initiate runaway thermonuclear fusion causing the white dwarf to explode as a supernova. The shape of the observed distribution of white dwarfs with masses up to $1.25 M_{\\odot}$ rules out primordial black holes with masses $\\sim 10^{19}$ gm - $10^{20}$ gm as a dominant constituent of the local dark matter density. Black holes with masses as large as $10^{24}$ gm will be excluded if recent observations by the NuStar collaboration of a population of white dwarfs near the galactic center are confirmed. Black holes in the mass range $10^{20}$ gm - $10^{22}$ gm are also constrained by the observed supernova rate, though these bounds are subject to astrophysical uncertainties. These bounds can be further strengthened through measurements of white dwarf binaries in gravitational wave observatories. The mechanism proposed in this paper can constrain a variety of other dark matter scenarios such as Q balls, annihilation/collision of large composite states of dark matter and models of dark matter where the accretion of dark matter leads to the formation of compact cores within the star. White dwarfs, with their astronomical lifetimes and sizes, can thus act as large space-time volume detectors enabling a unique probe of the properties of dark matter, especially of dark matter candidates that have low number density. This mechanism also raises the intriguing possibility that a class of supernova may be triggered through rare events induced by dark matter rather than the conventional mechanism of accreting white dwarfs that explode upon reaching the Chandrasekhar mass.

  20. Cosmology, Thermodynamics and Matter Creation

    E-Print Network [OSTI]

    J. A. S. Lima; M. O. Calvao; I. Waga

    2007-08-24

    Several approaches to the matter creation problem in the context of cosmological models are summarily reviewed. A covariant formulation of the general relativistic imperfect simple fluid endowed with a process of matter creation is presented. By considering the standard big bang model, it is shown how the recent results of Prigogine et alii \\cite{1} can be recovered and, at the same time their limits of validity are explicited.