Property:NbrProdWells | Open Energy Information
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Pfeifer, Holger
1 Complete Quantitative online Analysis of Methanol Electrooxidation Prod- ucts via Electron Impact for application in energy re- lated electrocatalysis is demonstrated using continuous methanol oxidation over
int. j. prod. res., 2001, vol. 39, no. 16, 35613600 A review of agile manufacturing systems
Nagi, Rakesh
(Sheridan 1993, Struebing 1995, Richards 1996, Nagel and Dove 1991). For many, `Lean manufacturing' and `Agile manufacturing' sound similar, but they are di erent. Lean manufacturing is a responseint. j. prod. res., 2001, vol. 39, no. 16, 3561±3600 A review of agile manufacturing systems LUIS M
Scaling up ATLAS production system for the LHC Run 2 and beyond: project ProdSys2
Borodin, Mikhail; The ATLAS collaboration; García Navarro, José Enrique; Golubkov, Dmitry; Klimentov, Alexei; Maeno, Tadashi; Vaniachine, Alexandre
2015-01-01
The Big Data processing needs of the ATLAS experiment grow continuously, as more data and more use cases emerge. For Big Data processing the ATLAS experiment adopted the data transformation approach, where software applications transform the input data into outputs. In the ATLAS production system, each data transformation is represented by a task, a collection of many jobs, submitted by the ATLAS workload management system (PanDA) and executed on the Grid. Our experience shows that the rate of tasks submission grows exponentially over the years. To scale up the ATLAS production system for new challenges, we started the ProdSys2 project. PanDA has been upgraded with the Job Execution and Definition Interface (JEDI). Patterns in ATLAS data transformation workflows composed of many tasks, provided a scalable production system framework for template definitions of the many-tasks workflows. These workflows are being implemented in the Database Engine for Tasks (DEfT) that generates individual tasks for processing ...
Paired t testsPaired t tests Paired (dependent) t-testPaired (dependent) t test
Wolverton, Steve
Paired t testsPaired t tests #12;Paired (dependent) t-testPaired (dependent) t test · Compares test means from matched pairsCompares test means from matched pairs or two different samples from the same individualsindividuals e.g., pretest & post test scores for the same group of students Ho: d = 0 d is thedifference
pp: 1-6 (col.fig.: Nil) PROD. TYPE: COM PAGN: Murthy.N --SCAN: Shubha
Ganichev, Sergey
temperature. Two pairs of ohmic contacts have been centered along opposite sample edges. For 45 optical 3)-grown GaAs QWs of Cs symmetry normalized by the light power P as a function of the phase angle
Oertner, Thomas
. These products may be covered by one or more Limited Use Label Licenses (see Invitrogen catalog or www Limited Use Label Licenses (see Invitrogen catalog or www.invitrogen.com). By use of these prod- ucts you of commonly used imag- ing techniques. Illuminated Neurons TPE excitation through water immersion objective
Optimal Pairings F. Vercauteren
International Association for Cryptologic Research (IACR)
Optimal Pairings F. Vercauteren Department of Electrical Engineering, Katholieke Universiteit pairing is completely determined by its value on one set of generators of G1, G2: let G1 = P , G2 = Q with the occasional jumps caused by fundamentally new approaches. One line of research is focused on shortening
Optimal Pairings F. Vercauteren #
International Association for Cryptologic Research (IACR)
Optimal Pairings F. Vercauteren # Department of Electrical Engineering, Katholieke Universiteit. Indeed, every pairing is completely determined by its value on one set of generators of G 1 , G 2 : let G improved ef ficiency, interspersed with the occasional jumps caused by fundamentally new approaches. One
James Valles
2010-01-08
Nearly 50 years elapsed between the discovery of superconductivity and the emergence of the microscopic theory describing this zero resistance state. The explanation required a novel phase of matter in which conduction electrons joined in weakly bound pairs and condensed with other pairs into a single quantum state. Surprisingly, this Cooper pair formation has also been invoked to account for recently uncovered high-resistance or insulating phases of matter. To address this possibility, we have used nanotechnology to create an insulating system that we can probe directly for Cooper pairs. I will present the evidence that Cooper pairs exist and dominate the electrical transport in these insulators and I will discuss how these findings provide new insight into superconductor to insulator quantum phase transitions.
Brazos River Erosion Management Project (BREM) Briefing Paper
US Army Corps of Engineers
in Section 219, Water Resources Development Act of 1992, for Environmental Infrastructure Projects of historic Brazos River alluvium, extending downstream to the Gulf of Mexico. Additional scour and soil loss by Fort Bend County and private property. Additionally, further erosion will impact public infrastructure
Annual Energy Outlook [U.S. Energy Information Administration (EIA)]
15,797.3 8,244.4 1,805.1 7,348.9 9,154.0 81,732.8 a Includes refuse recovery. except biofuels. b Marketed production. f Production of federal offshore natural gas along the c...
Gasoline and Diesel Fuel Update (EIA)
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 GasAdjustments (Billion Cubic Feet) Wyoming Dry NaturalPrices1Markets160 OctoberFeet)22,108.15,452.33 2013
Multiprocessor switch with selective pairing
Gara, Alan; Gschwind, Michael K; Salapura, Valentina
2014-03-11
System, method and computer program product for a multiprocessing system to offer selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). Each paired microprocessor or processor cores that provide one highly reliable thread for high-reliability connect with a system components such as a memory "nest" (or memory hierarchy), an optional system controller, and optional interrupt controller, optional I/O or peripheral devices, etc. The memory nest is attached to a selective pairing facility via a switch or a bus
Nomura, Kazumasa
2007-01-01
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of $K$-linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfies the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering ${V_i}_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering ${V^*_i}_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
NONSMOOTH LYAPUNOV PAIRS FOR INFINITE-DIMENSIONAL ...
2010-05-27
continuous Lyapunov pairs or functions associated to first-order differential ... continuous Lyapunov pairs and functions, invariance of sets, subdifferential sets,
Tridiagonal pairs of Krawtchouk type
Ito, Tatsuro
2007-01-01
Let $K$ denote an algebraically closed field with characteristic 0 and let $V$ denote a vector space over $K$ with finite positive dimension. Let $A,A^*$ denote a tridiagonal pair on $V$ with diameter $d$. We say that $A,A^*$ has Krawtchouk type whenever the sequence $\\lbrace d-2i\\rbrace_{i=0}^d$ is a standard ordering of the eigenvalues of $A$ and a standard ordering of the eigenvalues of $A^*$. Assume $A,A^*$ has Krawtchouk type. We show that there exists a nondegenerate symmetric bilinear form $$ on $V$ such that $= $ and $= $ for $u,v\\in V$. We show that the following tridiagonal pairs are isomorphic: (i) $A,A^*$; (ii) $-A,-A^*$; (iii) $A^*,A$; (iv) $-A^*,-A$. We give a number of related results and conjectures.
The ion pairs and superconducting bosons
V. N. Minasyan
2009-02-11
First, it is shown that the creation of the spinless ion pairs in the lattice, which are hold by the binding with neighbor ion pairs together regarded as covalent. These ion pairs are created by the repulsive potential interaction of two ions which is bound as linear oscillator. The repulsive S-wave scattering between ion pairs and electrons is transformed to the attractive effective interaction between electrons which leads to a creation of electron pairs by a binding energy depending on the condensate fraction of ion pairs $\\frac{N_0}{N}$. In this respect, the absence of ion pairs in the condensate destroys a binding energy of electron pairs and in turn so-called superconductimg phase. As new result presented theory is that the number of the superconducting bosons is not changed in the superconducting phase.
Microsoft Word - 08071744_DocProd.doc
Office of Legacy Management (LM)
well. Monitor wells with an "SC" suffix are completed in the Upper Sand aquifer of the Wind River Formation. Wells with a "DC" suffix are completed in the Main Sand aquifer, and...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
September 11, 1997 Particle Production at 0 from the Collider K. W. Del Signore, H. R. Gustafson, K. D. Hanson, L. W. Jones, M. J. Longo*, F. Lopez University of Michigan, Ann...
Microsoft Word - 08031475_DocProd.doc
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 MyersHr. Anthony V.How DOE and the TriSAL/S04639
Microsoft Word - 07121310 DocProd.doc
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,Grand JunctionMSGOUIDMay and
Microsoft Word - 08021395 DocProd.doc
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,Grand JunctionMSGOUIDMay andSHP/S04483 U.S.
Microsoft Word - 08071744_DocProd.doc
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,Grand JunctionMSGOUIDMay andSHP/S04483
Microsoft Word - 08101898_DocProd.doc
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,Grand JunctionMSGOUIDMaySampling at theand
Pairing Correlations in halo Nuclei
H. Sagawa; K. Hagino
2007-09-10
Paring correlations in weakly bound halo nuclei $^{6}$He and $^{11}$Li are studied by using a three-body model with a density-dependent contact interaction. We investigate the spatial structure of two-neutron wave function in a Borromean nucleus $^{11}$Li.The behavior of the neutron pair at different densities is simulated by calculating the two-neutron wave function at several distances between the core nucleus $^9$Li and the center of mass of the two neutrons. With this representation, a strong concentration of the neutron pair on the nuclear surface is quantitatively established for neutron-rich nuclei. Dipole excitations in $^{6}$He and $^{11}$Li are also studied within the same three-body model and compared with experimental data. The small open angles between the two neutrons from the core are extracted empirically by the B(E1) sum rule together with the rms mass radii, indicating the strong di-neutron correlation in the halo nuclei.
Galaxy pairs align with galactic filaments
Tempel, Elmo
2015-01-01
Context. Gravitational collapse theory and numerical simulations suggest that the velocity field within large-scale galaxy filaments is dominated by motions along the filaments. Aims. Our aim is to check whether observational data reveal any preferred orientation of galaxy pairs with respect to the underlying filaments as a result of the expectedly anisotropic velocity field. Methods. We use galaxy pairs and galaxy filaments identified from the Sloan Digital Sky Survey data. For filament extraction, we use the Bisous model that is based the marked point process technique. During the filament detection, we use the centre point of each pair instead of the positions of galaxies to avoid a built-in influence of pair orientation on the filament construction. For pairs lying within filaments (3012 cases), we calculate the angle between the line connecting galaxies of each pair and their host filament. To avoid redshift-space distortions, the angle is measured in the plain of the sky. Results. The alignment analysis...
Pairing Effects in Nuclear Fusion Reaction
Shuichiro Ebata; Takashi Nakatsukasa
2013-09-29
We simulate a heavy-ion collision using the canonical-basis time-dependent Hartree-Fock-Bogoliubov theory (Cb-TDHFB) treating pairing correlation in the three-dimensional coordinate space. We apply the Cb-TDHFB to 22O+22O collision with a contact-type pairing energy functional, and compare results of Cb-TDHFB and TDHF to investigate the effects of pairing correlations in nuclear fusion. Our results seem to indicate that pairing effects do not increase the fusion cross section in this system.
Pairing, pseudogap and Fermi arcs in cuprates
Kaminski, Adam; Gu, Genda; Kondo, Takeshi; Takeuchi, Tsunehiro
2014-04-29
We use Angle Resolved Photoemission Spectroscopy (ARPES) to study the relationship between the pseudogap, pairing and Fermi arcs in cuprates. High quality data measured over a wide range of dopings reveals a consistent picture of Fermiology and pairing in these materials. The pseudogap is due to an ordered state that competes with superconductivity rather than preformed pairs. Pairing does occur below T_{pair} ~ 150K and significantly above T_{c}, but well below T* and the doping dependence of this temperature scale is distinct from that of the pseudogap. The d-wave gap is present below T_{pair}, and its interplay with strong scattering creates “artificial” Fermi arcs for T_{c} < T < T_{pair}. However, above T_{pair}, the pseudogap exists only at the antipodal region. This leads to presence of real, gapless Fermi arcs close to the node. The length of these arcs remains constant up to T*, where the full Fermi surface is recovered. We demonstrate that these findings resolve a number of seemingly contradictory scenarios.
Pairing, pseudogap and Fermi arcs in cuprates
Kaminski, Adam [Iowa State Univ., Ames, IA (United States); Gu, Genda [Brookhaven National Lab. (BNL), Upton, NY (United States); Kondo, Takeshi [The Univ. of Tokyo, Chiba (Japan); Takeuchi, Tsunehiro [Nagoya Univ., Nagoya (Japan)
2014-10-31
We use Angle Resolved Photoemission Spectroscopy (ARPES) to study the relationship between the pseudogap, pairing and Fermi arcs in cuprates. High quality data measured over a wide range of dopings reveals a consistent picture of Fermiology and pairing in these materials. The pseudogap is due to an ordered state that competes with superconductivity rather than preformed pairs. Pairing does occur below T_{pair} ~ 150K and significantly above T_{c}, but well below T* and the doping dependence of this temperature scale is distinct from that of the pseudogap. The d-wave gap is present below T_{pair}, and its interplay with strong scattering creates “artificial” Fermi arcs for T_{c} < T < T_{pair}. However, above T_{pair}, the pseudogap exists only at the antipodal region. This leads to presence of real, gapless Fermi arcs close to the node. The length of these arcs remains constant up to T*, where the full Fermi surface is recovered. We demonstrate that these findings resolve a number of seemingly contradictory scenarios.
Modularity of Termination Using Dependency Pairs ?
ÃbrahÃ¡m, Erika
Modularity of Termination Using Dependency Pairs ? Thomas Arts 1 and JÂ¨urgen Giesl 2 1 Computer@informatik.tuÂdarmstadt.de Abstract. The framework of dependency pairs allows automated terÂ mination and innermost termination proofs of this framework in order to prove termination in a modular way. Our modÂ ularity results significantly increase
Shell model study of the pairing correlations
J. A. Sheikh; P. A. Ganai; R. P. Singh; R. K. Bhowmick; S. Frauendorf
2007-12-19
A systematic study of the pairing correlations as a function of temperature and angular momentum has been performed in the sd-shell region using the spherical shell model approach. The pairing correlations have been derived for even-even, even-odd and odd-odd systems near N=Z and also for the asymmetric case of N=Z+4. The results indicate that the pairing content and the behavior of pair correlations is similar in even-even and odd-mass nuclei. For odd-odd N=Z system, angular momentum I=0 state is an isospin, t=1 neutron-proton paired configuration. Further, these t=1 correlations are shown to be dramatically reduced for the asymmetric case of N=Z+4. The shell model results obtained are qualitatively explained within a simplified degenerate model.
Pair creation in heavy ion channeling
Nikolay A. Belov; Zoltán Harman
2014-11-20
Heavy ions channeling through crystals with multi-GeV kinetic energies can create electron-positron pairs. In the framework of the ion, the energy of virtual photons arising from the periodic crystal potential may exceed the threshold $2mc^2$. The repeated periodic collisions with the crystal ions yield high pair production rates. When the virtual photon frequency matches a nuclear transition in the ion, the production rate can be resonantly increased. In this two-step excitation-pair conversion scheme, the excitation rates are coherently enhanced, and they scale approximately quadratically with the number of crystal sites along the channel.
Pair Creation at Large Inherent Angles
Chen, P.; Tauchi, T.; Schroeder, D.V.; /SLAC
2007-04-25
In the next-generation linear colliders, the low-energy e{sup +}e{sup -} pairs created during the collision of high-energy e{sup +}e{sup -} beams would cause potential deleterious background problems to the detectors. At low collider energies, the pairs are made essentially by the incoherent process, where the pair is created by the interaction of beamstrahlung photons on the individual particles in the oncoming beam. This problem was first identified by Zolotarev, et al[1]. At energies where the beamstrahlung parameter {Upsilon} lies approximately in the range 0.6 {approx}< {Upsilon} {approx}< 100, pair creation from the beamstrahlung photons is dominated by a coherent process, first noted by Chen[2]. The seriousness of this pair creation problem lies in the transverse momenta that the pair particles carry when leaving the interaction point (IP) with large angles. One source of transverse momentum is from the kick by the field of the oncoming beam which results in an outcoming angle {theta} {proportional_to} 1/{radical}x, where x is the fractional energy of the particle relative to the initial beam particle energy[2,3]. As was shown in Ref. 131, there in fact exists an energy threshold for the coherent pairs, where x{sub th} {approx}> 1/2{Upsilon}. Thus within a tolerable exiting angle, there exists an upper limit for {Upsilon} where all coherent pairs would leave the detector through the exhaust port[4]. A somewhat different analysis has been done by Schroeder[5]. In the next generation of linear colliders, as it occurs, the coherent pairs can be exponentially suppressed[2] by properly choosing the {Upsilon}({approx}< 0.6). When this is achieved, the incoherent pairs becomes dominant. Since the central issue is the transverse momentum for particles with large angles, we notice that there is another source for it. Namely, when the pair particles are created at low energies, the intrinsic angles of these pairs when produced may already be large. This issue was first studied in Ref. [1]. In this paper we reinvestigate the problem, following essentially the same equivalent photon approach, but with changes in specific details including the virtual photon spectrum. In addition, various assumptions are made more explicit. The formulas derived are then applied to the collider parameters designed by Palmer[6].
Improved Side Channel Attacks on Pairing Based Cryptography
International Association for Cryptologic Research (IACR)
], and anonymous group signatures [BS04] make use of pairings as their building blocks. The adoption of pairings that analyze the vulnerability of pairings to passive attacks as well as to active attacks [PV04, KTH+ 06, WS06, WS07, PV06]. There is a variety of pairings that can be used for PBC, e.g., the Weil pairing
Leonard pairs from 24 points of view
Paul Terwilliger
2004-06-28
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V\\to V$ and $A^*:V\\to V$ that satisfy both conditions below: (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is diagonal and the matrix representing $A^*$ is irreducible tridiagonal. (ii) There exists a basis for $V$ with respect to which the matrix representing $A^*$ is diagonal and the matrix representing $A$ is irreducible tridiagonal. We call such a pair a {\\it Leonard pair} on $V$. Referring to the above Leonard pair, we investigate 24 bases for $V$ on which the action of $A$ and $A^*$ takes an attractive form. With respect to each of these bases, the matrices representing $A$ and $A^*$ are either diagonal, lower bidiagonal, upper bidiagonal, or tridiagonal.
Schwinger pair creation in multilayer graphene
M. A. Zubkov
2012-04-05
The low energy effective field model for the multilayer graphene (at ABC stacking) in external Electric field is considered. The Schwinger pair creation rate and the vacuum persistence probability are calculated using the semi - classical approach.
90 Seconds of Discovery: Frustrated Lewis Pairs
Kathmann, Shawn; Schenter, Greg; Autrey, Tom
2014-07-21
Hydrogen activating catalysts play an important role in producing valuable chemicals, such as biofuels and ammonia. As a part of efforts to develop the next generation of these catalysts, PNNL researchers have found potential in Frustrated Lewis Pairs.
90 Seconds of Discovery: Frustrated Lewis Pairs
Kathmann, Shawn; Schenter, Greg; Autrey, Tom
2014-02-14
Hydrogen activating catalysts play an important role in producing valuable chemicals, such as biofuels and ammonia. As a part of efforts to develop the next generation of these catalysts, PNNL researchers have found potential in Frustrated Lewis Pairs.
Nuclear Scissors with Pairing and Continuity Equation
E. B. Balbutsev; L. A. Malov; P. Schuck; M. Urban
2008-10-29
The coupled dynamics of the isovector and isoscalar giant quadrupole resonances and low lying modes (including scissors) are studied with the help of the Wigner Function Moments (WFM) method generalized to take into account pair correlations. Equations of motion for collective variables are derived on the basis of the Time Dependent Hartree-Fock-Bogoliubov (TDHFB) equations in the harmonic oscillator model with quadrupole-quadrupole (QQ) residual interaction and a Gaussian pairing force. Special care is taken of the continuity equation.
Pair programming improves student retention, confidence, and program quality
McDowell, C; Werner, L; Bullock, H E; Fernald, J
2006-01-01
Werner, L.L. Building Pair Programming Knowledge through aJ. The Impact of Pair Programming on Student Performance andto Know About Pair Programming I Learned in Kindergarten.
Nuclear elements in Banach Jordan pairs Ottmar Loos
Nuclear elements in Banach Jordan pairs Ottmar Loos Abstract We introduce nuclear elements in Banach Jordan pairs, generalizing the nuclear elements Jordan pairs and show that the trace form Trintroduced in [3] may be extended to the nuclear
Hartree-Fock-Bogoliubov solution of the pairing Hamiltonian in...
Office of Scientific and Technical Information (OSTI)
to pairing correlations, we show how the correlated pairs are incorporated into the HFB wave function. Thereafter, we present derivation and structure of the HFB equations within...
Pairing and specific heat in hot nuclei
Danilo Gambacurta; Denis Lacroix; Nicu Sandulescu
2013-07-15
The thermodynamics of pairing phase-transition in nuclei is studied in the canonical ensemble and treating the pairing correlations in a finite-temperature variation after projection BCS approach (FT-VAP). Due to the restoration of particle number conservation, the pairing gap and the specific heat calculated in the FT-VAP approach vary smoothly with the temperature, indicating a gradual transition from the superfluid to the normal phase, as expected in finite systems. We have checked that the predictions of the FT-VAP approach are very accurate when compared to the results obtained by an exact diagonalization of the pairing Hamiltonian. The influence of pairing correlations on specific heat is analysed for the isotopes $^{161,162}$Dy and $^{171,172}$Yb. It is shown that the FT-VAP approach, applied with a level density provided by mean field calculations and supplemented, at high energies, by the level density of the back-shifted Fermi gas model, can approximate reasonably well the main properties of specific heat extracted from experimental data. However, the detailed shape of the calculated specific heat is rather sensitive to the assumption made for the mean field.
An inverse problem for Schwinger pair production
Hebenstreit, Florian
2015-01-01
The production of electron-positron pairs in time-dependent electric fields (Schwinger mechanism) depends non-linearly on the applied field profile. Accordingly, the resulting momentum spectrum is extremely sensitive to small variations of the field parameters. Owing to this non-linear dependence it is so far unpredictable how to choose a field configuration such that a predetermined momentum distribution is generated. We show that quantum kinetic theory along with optimal control theory can be used to approximately solve this inverse problem for Schwinger pair production. We exemplify this by studying the superposition of a small number of harmonic components resulting in predetermined signatures in the asymptotic momentum spectrum. In the long run, our results could facilitate the observation of this yet unobserved pair production mechanism in quantum electrodynamics by providing suggestions for tailored field configurations.
Thermodynamics of pairing transition in hot nuclei
Lang Liu; Zhen-Hua Zhang; Peng-Wei Zhao
2014-12-16
The pairing correlations in hot nuclei $^{162}$Dy are investigated in terms of the thermodynamical properties by covariant density functional theory. The heat capacities $C_V$ are evaluated in the canonical ensemble theory and the paring correlations are treated by a shell-model-like approach, in which the particle number is conserved exactly. A S-shaped heat capacity curve, which agrees qualitatively with the experimental data, has been obtained and analyzed in details. It is found that the one-pair-broken states play crucial roles in the appearance of the S shape of the heat capacity curve. Moreover, due to the effect of the particle-number conservation, the pairing gap varies smoothly with the temperature, which indicates a gradual transition from the superfluid to the normal state.
Thermodynamics of pairing in mesoscopic systems
Tony Sumaryada; Alexander Volya
2007-06-12
Using numerical and analytical methods implemented for different models we conduct a systematic study of thermodynamic properties of pairing correlation in mesoscopic nuclear systems. Various quantities are calculated and analyzed using the exact solution of pairing. An in-depth comparison of canonical, grand canonical, and microcanonical ensemble is conducted. The nature of the pairing phase transition in a small system is of a particular interest. We discuss the onset of discontinuity in the thermodynamic variables, fluctuations, and evolution of zeros of the canonical and grand canonical partition functions in the complex plane. The behavior of the Invariant Correlational Entropy is also studied in the transitional region of interest. The change in the character of the phase transition due to the presence of magnetic field is discussed along with studies of superconducting thermodynamics.
Thermodynamics of pairing transition in hot nuclei
Lang Liu; Zhen-Hua Zhang; Peng-Wei Zhao
2015-10-09
The pairing correlations in hot nuclei $^{162}$Dy are investigated in terms of the thermodynamical properties by covariant density functional theory. The heat capacities $C_V$ are evaluated in the canonical ensemble theory and the paring correlations are treated by a shell-model-like approach, in which the particle number is conserved exactly. A S-shaped heat capacity curve, which agrees qualitatively with the experimental data, has been obtained and analyzed in details. It is found that the one-pair-broken states play crucial roles in the appearance of the S shape of the heat capacity curve. Moreover, due to the effect of the particle-number conservation, the pairing gap varies smoothly with the temperature, which indicates a gradual transition from the superfluid to the normal state.
Isominkowskian theory of Cooper Pairs in superconductors
Animalu, A.O.E. [Univ. of Nigeria, Nsukka (Nigeria)
1993-10-01
Via the use of Santilli`s isominkowskian space, the author presents a relativistic extension of the author`s recent treatment of the Cooper Pair in superconductivity based on the Lie-isotopic lifting of quantum mechanics known as Hadronic Mechanics. The isominkowskian treatment reduces the solution of the eiganvalue problem for the quasiparticle energy spectrum to a geometric problem of specifying the metric of the isominkowskian space inside the pair in various models of ordinary high T{sub c} superconductors. The use of an intriguing realization of the metric due to Dirac reduces the dimensionality of the interior space to two yielding a spin mutation from 1/2 to zero inside a Cooper pair in two-band BCS and Hubbard models. 12 refs.
Yoshiaki Tsujimoto; Yukihiro Sugiura; Makoto Ando; Daisuke Katsuse; Rikizo Ikuta; Takashi Yamamoto; Masato Koashi; Nobuyuki Imoto
2015-03-10
We experimentally demonstrated entanglement extraction scheme by using photons at the telecommunication band for optical-fiber-based quantum communications. We generated two pairs of non-degenerate polarization entangled photons at 780~nm and 1551~nm by spontaneous parametric down-conversion and distributed the two photons at 1551~nm through a collective phase damping channel which gives the same amount of random phase shift on the two photons. Through local operation and classical communication, we extracted an entangled photon pair from two phase-disturbed photon pairs. An observed fidelity of the extracted photon pair to a maximally entangled photon pair was 0.73 $\\pm$ 0.07 which clearly shows the recovery of entanglement.
Quantum Key Distribution with Qubit Pairs
Mohd Asad Siddiqui; Tabish Qureshi
2014-07-17
We propose a new Quantum Key Distribution method in which Alice sends pairs of qubits to Bob, each in one of four possible states. Bob uses one qubit to generate a secure key and the other to generate an auxiliary key. For each pair he randomly decides which qubit to use for which key. The auxiliary key has to be added to Bob's secure key in order to match Alice's secure key. This scheme provides an additional layer of security over the standard BB84 protocol.
Single top and top pair production
Nikolaos Kidonakis
2012-12-12
I present results for single-top and top-pair production at the LHC and the Tevatron. Higher-order two-loop corrections are used to achieve NNLL resummation, which is then used to derive NNLO soft-gluon corrections. Results are presented for total cross sections, top transverse momentum distributions, and top rapidity distributions. All results are in excellent agreement with data from the LHC and the Tevatron. I also clarify the differences between various methods in top-pair production and their relation to exact NNLO results.
Cryptographic Schemes based on Elliptic Curve Pairings
Paterson, Kenny
on Elliptic Curve Pairings: Contributions to Public Key Cryptography and Key Agreement Protocols This thesis are then used to make concrete CL-PKC schemes and are also used to make other efficient key agreement protocols. It does rely on the use of a trusted authority (TA) who is in possession of a master key. In this respect
Efficient Pairings and ECC for Embedded Systems
International Association for Cryptologic Research (IACR)
Efficient Pairings and ECC for Embedded Systems Thomas Unterluggauer and Erich Wenger Graz-based cryptography brought forth a wide range of protocols interesting for future embedded applications. One curve and its reusability for other elliptic-curve based crypto systems offer a great solution for every
Improved Modular Termination Proofs Using Dependency Pairs
Middeldorp, Aart
Improved Modular Termination Proofs Using Dependency Pairs RenÂ´e Thiemann, JÂ¨urgen Giesl, Peter) termination proofs of term rewrite systems (TRSs). For any TRS, it generates inequality constraints that have to be satisfied by well-founded orders. However, proving innermost termination is considerably easier than
Improved Modular Termination Proofs Using Dependency Pairs
ÃbrahÃ¡m, Erika
Improved Modular Termination Proofs Using Dependency Pairs Renâ??e Thiemann, JË?urgen Giesl, Peter) termination proofs of term rewrite systems (TRSs). For any TRS, it generates inequality constraints that have to be satisfied by wellÂfounded orders. However, proving innermost termination is considerably easier than
Abstract polymer models with general pair interactions
Aldo Procacci
2008-11-26
A convergence criterion of cluster expansion is presented in the case of an abstract polymer system with general pair interactions (i.e. not necessarily hard core or repulsive). As a concrete example, the low temperature disordered phase of the BEG model with infinite range interactions, decaying polynomially as $1/r^{d+\\lambda}$ with $\\lambda>0$, is studied.
Pairing, pseudogap and Fermi arcs in cuprates
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Kaminski, Adam; Kondo, Takeshi; Takeuchi, Tsunehiro; Gu, Genda
2014-04-29
We use Angle Resolved Photoemission Spectroscopy (ARPES) to study the relationship between the pseudogap, pairing and Fermi arcs in cuprates. High quality data measured over a wide range of dopings reveals a consistent picture of Fermiology and pairing in these materials. The pseudogap is due to an ordered state that competes with superconductivity rather than preformed pairs. Pairing does occur below Tpair ~ 150K and significantly above Tc, but well below T* and the doping dependence of this temperature scale is distinct from that of the pseudogap. The d-wave gap is present below Tpair, and its interplay with strong scatteringmore »creates “artificial” Fermi arcs for Tc ? T ? Tpair. However, above Tpair, the pseudogap exists only at the antipodal region. This leads to presence of real, gapless Fermi arcs close to the node. The length of these arcs remains constant up to T*, where the full Fermi surface is recovered. As a result, we demonstrate that these findings resolve a number of seemingly contradictory scenarios.« less
All Paired Up with No Place to Go: Pairing, Synapsis, and DSB Formation in a Balancer Heterozygote
Gong, Wei J; McKim, Kim S; Hawley, R. Scott
2005-11-18
period of re-pairing in meiotic prophase. This observation supports the assertion made by Roeder and Weiner et al. [4,5] that the ability of Drosophila females to form a synaptonemal complex (SC) between homologous chromo- somes in the absence of double..., it is possible that despite previous somatic pairings, pairing might still need to be re- established in female meiotic prophase immediately prior to SC formation. In other words, rather than proposing that meiotic pairings are extensions of somatic pairings...
Resonant tunneling of fluctuation Cooper pairs
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Galda, Alexey; Mel'nikov, A. S.; Vinokur, V. M.
2015-02-09
Superconducting fluctuations have proved to be an irreplaceable source of information about microscopic and macroscopic material parameters that could be inferred from the experiment. According to common wisdom, the effect of thermodynamic fluctuations in the vicinity of the superconducting transition temperature, Tc, is to round off all of the sharp corners and discontinuities, which otherwise would have been expected to occur at Tc. Here we report the current spikes due to radiation-induced resonant tunneling of fluctuation Cooper pairs between two superconductors which grow even sharper and more pronounced upon approach to Tc. This striking effect offers an unprecedented tool formore »direct measurements of fluctuation Cooper pair lifetime, which is key to our understanding of the fluctuation regime, most notably to nature of the pseudogap state in high-temperature superconductors. Our finding marks a radical departure from the conventional view of superconducting fluctuations as a blurring and rounding phenomenon.« less
Vortex Bubble Formation in Pair Plasmas
Berezhiani, V I; Mahajan, S M; Aleksi?, B N
2013-01-01
It is shown that delocalized vortex solitons in relativistic pair plasmas with small temperature asymmetries can be unstable for intermediate intensities of the background electromagnetic field. Instability leads to the generation of ever-expanding cavitating bubbles in which the electromagnetic fields are zero. The existence of such electromagnetic bubbles is demonstrated by qualitative arguments based on a hydrodynamic analogy, and by numerical solutions of the appropriate Nonlinear Schr\\"odinger equation with a saturating nonlinearity.
On the pairing effects in triaxial nuclei
Oudih, M. R. [Laboratoire de Physique Théorique, Faculté de Physique,USTHB BP 32, El Alia, 16111 Bab Ezzouar, Algiers (Algeria); Fellah, M.; Allal, N. H. [Centre de Recherche Nucléaire d'Alger, 2 Bd. Frantz Fanon, BP. 399 Alger-Gare, Algiers, Algeria and Laboratoire de Physique Théorique, Faculté de Physique,USTHB BP 32, El Alia, 16111 Bab Ezzouar, Algiers (Algeria)
2014-03-05
Triaxial deformation effect on the pairing correlations is studied in the framework of the Skyrme Hartree-Fock-Bogoliubov theory. Quantities such as binding energy, gap parameter and particle-number fluctuation are considered in neutron-rich Mo isotopes. The results are compared with those of axially symmetric calculation and with available experimental data. The role played by the particle-number projection is outlined.
Persistent Ion Pairing in Aqueous Hydrochloric Acid
Baer, Marcel D.; Fulton, John L.; Balasubramanian, Mahalingam; Schenter, Gregory K.; Mundy, Christopher J.
2014-07-03
For strong acids, like hydrochloric acid, the complete dissociation into an excess proton and conjugated base as well as the formation of independent solvated charged fragments is assumed. The existence of a chloride-Hyronium (Cl-H3O+) contact ion pairs even in moderate concentration hydrochloric acid (2.5 m) demonstrates that the counter ions do not behave merely as spectators. Through the use of modern extended X-ray absorption fine structure (EXAFS) measurements in conjunction with state-of-the-art density functional theory (DFT) simulations, we are able to obtain an unprecedented view into the molecular structure of medium to high concentrated electrolytes. Here we report that the Cl-H3O+ contact ion pair structure persists throughout the entire concentration range studied and that these structures differ significantly from moieties studied in micro-solvated hydrochloric acid clusters. Characterizing distinct populations of these ion pairs gives rise to a novel molecular level description of how to think about the activity of the proton that impacts our picture of the pH scale. Funding for CJM, GKS, and JLF was provided by DOE Office of Science, Office of Basic Energy Science, Division of Chemical Sciences, Geosciences, and Biosciences. Funding for MDB was provided throught the Laboratory Directed Research and Development program at Pacific Northwest National Laboratory. MB was funded through Argonne National Laboratory.
Search for pair production of first and second generation leptoquarks...
Office of Scientific and Technical Information (OSTI)
pair production of first and second generation leptoquarks in proton-proton collisions at sqrts 8 TeV Citation Details In-Document Search Title: Search for pair production...
Efficient Implementation of the T Pairing Yosuke Katoh1
International Association for Cryptologic Research (IACR)
of characteristics 3. We report the performance results of implementa- tions on NVIDIA GTX 285, GTX 480, Tesla C1060, and Tesla C2050 graphics cards. We have implemented T pairing in three different ways, namely, one pairing
A High Speed Pairing Coprocessor Using RNS and Lazy Reduction
International Association for Cryptologic Research (IACR)
A High Speed Pairing Coprocessor Using RNS and Lazy Reduction Gavin Xiaoxu Yao1 , Junfeng Fan2 using Residue Number System (RNS) and lazy reduction. We show that combining RNS, which are naturally pairing computation in 0.664 ms. Keywords: RNS, Moduli Selection, Hardware Implementation of Pairing, FPGA
E cient Implementation of the Pairing on Mobilephones using BREW
International Association for Cryptologic Research (IACR)
E cient Implementation of the Pairing on Mobilephones using BREW Motoi Yoshitomiy, Tsuyoshi Takagiy processors on BREW achieves under 100 milliseconds using the supersingular curve over F397 . It has become e encryption, using the pairing on BREW mobilephones. Keywords: Pairing Based Cryptosystem, Mobilephone, BREW
Schwinger Pair Production at Finite Temperature
Medina, Leandro
2015-01-01
Thermal corrections to Schwinger pair production are potentially important in particle physics, nuclear physics and cosmology. However, the lowest-order contribution, arising at one loop, has proved difficult to calculate unambiguously. We show that this thermal correction may be calculated for charged scalars using the worldline formalism, where each term in the decay rate is associated with a worldline instanton. We calculate all finite-temperature worldline instantons, their actions and fluctuations prefactors, thus determining the complete one-loop decay rate at finite temperature. The thermal contribution to the decay rate becomes nonzero at a threshold temperature T=eE/2m, above which it dominates the zero temperature result.
Nuclear Pairing from Two-body Microscopic Forces: Analysis of the Cooper Pair Wavefunctions
P. Finelli; S. Maurizio; J. W. Holt
2014-11-27
In a recent paper we studied the behavior of the pairing gaps $\\Delta_F$ as a function of the Fermi momentum $k_F$ for neutron and nuclear matter in all relevant angular momentum channels where superfluidity is believed to naturally emerge. The calculations employed realistic chiral nucleon-nucleon potentials with the inclusion of three-body forces and self-energy effects. In this contribution, after a detailed description of the numerical method we employed in the solution of the BCS equations, we will show a preliminary analysis of the Cooper pair wavefunctions.
Photoproduction of a ??Pair and Transversity GPDs
M. El Beiyad; B. Pire; L. Szymanowski; S. Wallon
2010-07-16
We demonstrate that the chiral-odd transversity generalized parton distributions (GPDs) of the nucleon can be accessed through the exclusive photoproduction process gamma + N -> pi + rho + N', in the kinematics where the meson pair has a large invariant mass and the final nucleon has a small transverse momentum, provided the vector meson is produced in a transversely polarized state. We calculate perturbatively the scattering amplitude at leading order in alpha_s: We build a simple model for the dominant transversity GPD HT (x; chi; t) based on the concept of double distribution. Counting rates estimates show that the experiment looks feasible with the real photon beam characteristics expected at JLab@12 GeV, in low Q2 leptoproduction at Jlab@12 GeV and in the COMPASS experiment.
Higher rank stable pairs and virtual localization
Artan Sheshmani
2015-02-08
We introduce a higher rank analog of the Pandharipande-Thomas theory of stable pairs on a Calabi-Yau threefold $X$. More precisely, we develop a moduli theory for frozen triples given by the data $O^r(-n)\\rightarrow F$ where $F$ is a sheaf of pure dimension 1. The moduli space of such objects does not naturally determine an enumerative theory: that is, it does not naturally possess a perfect symmetric obstruction theory. Instead, we build a zero-dimensional virtual fundamental class by hand, by truncating a deformation-obstruction theory coming from the moduli of objects in the derived category of $X$. This yields the first deformation-theoretic construction of a higher-rank enumerative theory for Calabi-Yau threefolds. We calculate this enumerative theory for local $\\mathbb{P}^1$ using the Graber-Pandharipande virtual localization technique.
Imaging with power controlled source pairs
Bardsley, Patrick
2015-01-01
Scatterers in a homogeneous medium are imaged by probing the medium with two point sources of waves modulated by correlated signals and by measuring only intensities at one single receiver. For appropriately chosen source pairs, we show that full waveform array measurements can be recovered from such intensity measurements by solving a linear least squares problem. The least squares solution can be used to image with Kirchhoff migration, even if the solution is determined only up to a known one-dimensional nullspace. The same imaging strategy can be used when the medium is probed with point sources driven by correlated Gaussian processes and autocorrelations are measured at a single location. Since autocorrelations are robust to noise, this can be used for imaging when the probing wave is drowned in background noise.
Method for sequencing DNA base pairs
Sessler, A.M.; Dawson, J.
1993-12-14
The base pairs of a DNA structure are sequenced with the use of a scanning tunneling microscope (STM). The DNA structure is scanned by the STM probe tip, and, as it is being scanned, the DNA structure is separately subjected to a sequence of infrared radiation from four different sources, each source being selected to preferentially excite one of the four different bases in the DNA structure. Each particular base being scanned is subjected to such sequence of infrared radiation from the four different sources as that particular base is being scanned. The DNA structure as a whole is separately imaged for each subjection thereof to radiation from one only of each source. 6 figures.
Pairing in bulk nuclear matter beyond BCS
Ding, D; Dickhoff, W H; Dussan, H; Rios, A; Polls, A
2014-01-01
The influence of short-range correlations on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the ${}^3P_2-{}^3F_2$ coupled channel in pure neutron matter. This effect is studied for different realistic interactions including one based on chiral perturbation theory. The gap in this channel vanishes at all relevant densities due to the treatment of these correlations. We also consider the effect of long-range correlations by including polarization terms in addition to the bare interaction which allow the neutrons to exchange density and spin fluctuations governed by the strength of Landau parameters allowed to have reasonable values consistent with the available literature. Preliminary results indicate that reasonable values of these parameters do not generate a gap in the ${}^3P_2-{}^3F_2$ coupled channel either for all three realistic interactions although the pairing interaction becomes slightly more attractive.
Analysis of food pairing in regional cuisines of India
Jain, Anupam; Bagler, Ganesh
2015-01-01
Any national cuisine is a sum total of its variety of regional cuisines, which are the cultural and historical identifiers of their respective regions. India is home to a number of regional cuisines that showcase its culinary diversity. Here, we study recipes from eight different regional cuisines of India spanning various geographies and climates. We investigate the phenomenon of food pairing which examines compatibility of two ingredients in a recipe in terms of their shared flavor compounds. Food pairing was enumerated at the level of cuisine, recipes as well as ingredient pairs by quantifying flavor sharing between pairs of ingredients. Our results indicate that each regional cuisine follows negative food pairing pattern; more the extent of flavor sharing between two ingredients, lesser their co-occurrence in that cuisine. We find that frequency of ingredient usage is central in rendering the characteristic food pairing in each of these cuisines. Spice and dairy emerged as the most significant ingredient ...
Distinguishing LSP archetypes via gluino pair production at LHC13...
Office of Scientific and Technical Information (OSTI)
Distinguishing LSP archetypes via gluino pair production at LHC13 Citation Details In-Document Search This content will become publicly available on August 19, 2016 Title:...
Theoretical overview on top pair production and single top production
Stefan Weinzierl
2012-01-19
In this talk I will give an overview on theoretical aspects of top quark physics. The focus lies on top pair production and single top production.
Large Higgs energy region in Higgs associated top pair production...
Office of Scientific and Technical Information (OSTI)
Large Higgs energy region in Higgs associated top pair production at the Linear Collider Citation Details In-Document Search Title: Large Higgs energy region in Higgs associated...
Tridiagonal pairs of $q$-Racah type
Ito, Tatsuro
2008-01-01
Let $K$ denote an algebraically closed field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\lbrace V_i\\rbrace_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\lbrace V^*_i\\rbrace_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
How to sharpen a tridiagonal pair
Ito, Tatsuro
2008-01-01
Let $\\F$ denote a field and let $V$ denote a vector space over $\\F$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\lbrace V_i\\rbrace_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\lbrace V^*_i\\rbrace_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
A classification of sharp tridiagonal pairs
Ito, Tatsuro; Terwilliger, Paul
2010-01-01
Let $F$ denote a field and let $V$ denote a vector space over $F$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\lbrace V_i\\rbrace_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\lbrace V^*_i\\rbrace_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
On the shape of a tridiagonal pair
Nomura, Kazumasa
2009-01-01
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\lbrace V_i\\rbrace_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\lbrace V^*_i\\rbrace_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
The structure of a tridiagonal pair
Nomura, Kazumasa
2008-01-01
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\{V_i\\}_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_i + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\{V^*_i\\}_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_i + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv)there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
Tridiagonal pairs and the $\\mu$-conjecture
Nomura, Kazumasa
2009-01-01
Let $F$ denote a field and let $V$ denote a vector space over $F$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\{V_i\\}_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\{V^*_i\\}_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
Towards a classification of the tridiagonal pairs
Nomura, Kazumasa
2008-01-01
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. Let $End(V)$ denote the $K$-algebra consisting of all $K$-linear transformations from $V$ to $V$. We consider a pair $A,A^* \\in End(V)$ that satisfy (i)--(iv) below: (i) Each of $A,A^*$ is diagonalizable. (ii) There exists an ordering $\\{V_i\\}_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$. (iii) There exists an ordering $\\{V^*_i\\}_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$. (iv) There is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
Nebular spectra of pair-instability supernovae
Jerkstrand, A; Heger, A
2015-01-01
If very massive stars (M >~ 100 Msun) can form and avoid too strong mass loss during their evolution, they are predicted to explode as pair-instability supernovae (PISNe). One critical test for candidate events is whether their nucleosynthesis yields and internal ejecta structure, being revealed through nebular-phase spectra at t >~ 1 yr, match those of model predictions. Here we compute theoretical spectra based on model PISN ejecta at 1-3 years post-explosion to allow quantitative comparison with observations. The high column densities of PISNe lead to complete gamma-ray trapping for t >~ 2 years which, combined with fulfilled conditions of steady state, leads to bolometric supernova luminosities matching the 56Co decay. Most of the gamma-rays are absorbed by the deep-lying iron and silicon/sulphur layers. The ionization balance shows a predominantly neutral gas state, which leads to emission lines of Fe I, Si I, and S I. For low-mass PISNe the metal core expands slowly enough to produce a forest of distinc...
Jacobi Elliptic Monopole-Antimonopole Pair Solutions
Rosy Teh; Pei-Yen Tan; Khai-Ming Wong
2012-10-01
We present new classical generalized Jacobi elliptic one monopole - antimonopole pair (MAP) solutions of the SU(2) Yang-Mills-Higgs theory with the Higgs field in the adjoint representation. These generalized 1-MAP solutions are solved with $\\theta$-winding number $m$=1 and $\\phi$-winding number $n$=1, 2, 3, ... 6. Similar to the generalized Jacobi elliptic one monopole solutions, these generalized 1-MAP solutions are solved by generalizing the large distance behaviour of the solutions to the Jacobi elliptic functions and solving the second order equations of motion numerically when the Higgs potential is vanishing ($\\lambda$=0) and non vanishing ($\\lambda$=1). These generalized 1-MAP solutions possess total energies that are comparable to the total energy of the standard 1-MAP solution with winding number $m$=1. However these total energies are significantly lower than the total energy of the standard 1-MAP solution with winding number $m$=2. All these new generalized solutions are regular numerical finite energy non-BPS solutions of the Yang-Mills-Higgs field theory.
Pairing in bulk nuclear matter beyond BCS
Ding, D.; Dickhoff, W. H.; Dussan, H.; Witte, S. J.; Rios, A.; Polls, A.
2014-10-15
The influence of short-range correlations on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the {sup 3}P{sub 2}?{sup 3}F{sub 2} coupled channel in pure neutron matter. This effect is studied for different realistic interactions including one based on chiral perturbation theory. The gap in this channel vanishes at all relevant densities due to the treatment of these correlations. We also consider the effect of long-range correlations by including polarization terms in addition to the bare interaction which allow the neutrons to exchange density and spin fluctuations governed by the strength of Landau parameters allowed to have reasonable values consistent with the available literature. Preliminary results indicate that reasonable values of these parameters do not generate a gap in the {sup 3}P{sub 2}?{sup 3}F{sub 2} coupled channel either for all three realistic interactions although the pairing interaction becomes slightly more attractive.
Pairing-induced speedup of nuclear spontaneous fission
Jhilam Sadhukhan; J. Dobaczewski; W. Nazarewicz; J. A. Sheikh; A. Baran
2014-10-06
Collective inertia is strongly influenced at the level crossing at which quantum system changes diabatically its microscopic configuration. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of those configuration changes. Competition between pairing and level crossing is thus expected to have a profound impact on spontaneous fission lifetimes. To elucidate the role of nucleonic pairing on spontaneous fission, we study the dynamic fission trajectories of $^{264}$Fm and $^{240}$Pu using the state-of-the-art self-consistent framework. We employ the superfluid nuclear density functional theory with the Skyrme energy density functional SkM$^*$ and a density-dependent pairing interaction. Along with shape variables, proton and neutron pairing correlations are taken as collective coordinates. The collective inertia tensor is calculated within the nonperturbative cranking approximation. The fission paths are obtained by using the least action principle in a four-dimensional collective space of shape and pairing coordinates. Pairing correlations are enhanced along the minimum-action fission path. For the symmetric fission of $^{264}$Fm, where the effect of triaxiality on the fission barrier is large, the geometry of fission pathway in the space of shape degrees of freedom is weakly impacted by pairing. This is not the case for $^{240}$Pu where pairing fluctuations restore the axial symmetry of the dynamic fission trajectory. The minimum-action fission path is strongly impacted by nucleonic pairing. In some cases, the dynamical coupling between shape and pairing degrees of freedom can lead to a dramatic departure from the static picture. Consequently, in the dynamical description of nuclear fission, particle-particle correlations should be considered on the same footing as those associated with shape degrees of freedom.
Some Efficient Algorithms for the Final Exponentiation of T Pairing
International Association for Cryptologic Research (IACR)
Some Efficient Algorithms for the Final Exponentiation of T Pairing Masaaki Shirase1 , Tsuyoshi by the recent improvements, e.g., the Duursma-Lee algorithm and T pairing. In this paper we discuss how propose some efficient algorithms using the torus T2(F33n ) that can efficiently compute an inversion
LCPHSM2004005 Study of Higgs Boson Pair Production at
LCÂPHSMÂ2004Â005 March 2004 Study of Higgs Boson Pair Production at Linear Collider K. Desch a , TV for the measurement of the neutral Higgs boson properties within the framework of the MSSM. The process of associated Higgs boson production with subsequent decays of Higgs bosons into bÂquark and #Âlepton pairs
Crew Pairing Optimization with Genetic Harry Kornilakis and Panagiotis Stamatopoulos
Panagiotis, Stamatopoulos
- tions. The purpose of the crew pairing problem is to generate a set of pairings with minimal cost with near optimal cost. This problem, which is modelled by a set covering formulation, is solved with a genetic algorithm. The presented method was tested on actual flight data of Olympic Airways. 1
Pair Production of Topological anti de Sitter Black Holes
R. B. Mann
1996-07-28
The pair creation of black holes with event horizons of non-trivial topology is described. The spacetimes are all limiting cases of the cosmological $C$ metric. They are generalizations of the $(2+1)$ dimensional black hole and have asymptotically anti de Sitter behaviour. Domain walls instantons can mediate their pair creation for a wide range of mass and charge.
Pairing-Based Onion Routing with Improved Forward Secrecy
Goldberg, Ian
, Security Additional Key Words and Phrases: Onion routing, Tor, pairing-based cryptography, anonymous key29 Pairing-Based Onion Routing with Improved Forward Secrecy ANIKET KATE, GREG M. ZAVERUCHA, and IAN GOLDBERG University of Waterloo This article presents new protocols for onion routing anonymity
Density-matrix functionals for pairing in mesoscopic superconductors
Denis Lacroix; Guillaume Hupin
2010-09-03
A functional theory based on single-particle occupation numbers is developed for pairing. This functional, that generalizes the BCS approach, directly incorporates corrections due to particle number conservation. The functional is benchmarked with the pairing Hamiltonian and reproduces perfectly the energy for any particle number and coupling.
Efficient Implementation of Bilinear Pairings on ARM Processors
International Association for Cryptologic Research (IACR)
Efficient Implementation of Bilinear Pairings on ARM Processors Gurleen Grewal1 , Reza Azarderakhsh-Ate pairing over Barreto-Naehrig curves in software at differ- ent security levels on ARM processors. We computation on ARM-powered devices, outperforming by at least a factor of 3.7 the best previous results
RNS arithmetic in Fpk and application to fast pairing computation
International Association for Cryptologic Research (IACR)
RNS arithmetic in Fpk and application to fast pairing computation Sylvain Duquesne IRMAR, UMR CNRS and their extensions of small degree. We explain why it is very interesting to use RNS arithmetic for the base field Fp the case for pairing computations on ordinary curves (as MNT or BN curves). We prove that using RNS can
Minimizing communication in all-pairs shortest paths Edgar Solomonik
California at Berkeley, University of
Minimizing communication in all-pairs shortest paths Edgar Solomonik Aydin Buluc James Demmel;Copyright © 2013, by the author(s). All rights reserved. Permission to make digital or hard copies of all, requires prior specific permission. #12;Minimizing communication in all-pairs shortest paths Edgar
Nature Macmillan Publishers Ltd 1998 Paired-spike interactions
Reid, R. Clay
Nature © Macmillan Publishers Ltd 1998 8 Paired-spike interactions and synaptic efficacy of retinal that information encoded in the high firing rate of an individual retinal ganglion cell becomes distributed among is transmitted to the next level of processing. We made simultaneous recordings from 205 pairs of neurons
pp: 118 (col.fig.: 2) PROD. TYPE: COM
Bergmann, Michel
.990 1 Note on the determination of the ignition point in forest fires propagation using a control, France SUMMARY7 This paper is devoted to the determination of the origin point in forest fires propagation using a control algorithm. The forest fires propagation are mathematically modelled starting from
Prod-Trees: Semantic Search for Earth Observation Products
Koubarakis, Manolis
of set of self-describing, machine-independent data formats and software libraries that support search- ing for EO products by selecting some high level categories (e.g., the mission from which and temporal filtering criteria. Although this might suit the needs of very advanced users that know exactly
Microsoft Word - GFC-ATVProposedProd-Costs.doc
by: Kathleen Hennessey Date: October 30, 2008 U.S. Department of Energy Advanced Technology Vehicle Manufacturing Loan Program 1 GM-FORD-CHRYSLER Submitted by: Kathleen...
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Leonard pairs and the q-Racah polynomials
Paul Terwilliger
2008-07-24
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider an ordered pair of linear transformations $A:V\\to V$ and $A^*:V\\to V$ that satisfy conditions (i), (ii) below. (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is irreducible tridiagonal and the matrix representing $A^*$ is diagonal. (ii) There exists a basis for $V$ with respect to which the matrix representing $A$ is diagonal and the matrix representing $A^*$ is irreducible tridiagonal. We call such a pair a {\\it Leonard pair} on $V$. We discuss a correspondence between Leonard pairs and a class of orthogonal polynomials consisting of the $q$-Racah polynomials and some related polynomials of the Askey scheme. For the polynomials in this class we obtain the 3-term recurrence, difference equation, Askey-Wilson duality, and orthogonality in a uniform manner using the corresponding Leonard pair.
Semiclassical pair production rate for rotating electric fields
Eckhard Strobel; She-Sheng Xue
2015-02-09
We semiclassically investigate Schwinger pair production for pulsed rotating electric fields depending on time. To do so we solve the Dirac equation for two-component fields in a WKB-like approximation. The result shows that for two-component fields the spin distribution of produced pairs is generally not $1:1$. As a result the pair creation rates of spinor and scalar quantum electro dynamics (QED) are different even for one pair of turning points. For rotating electric fields the pair creation rate is dominated by particles with a specific spin depending on the sense of rotation for a certain range of pulse lengths and frequencies. We present an analytical solution for the momentum spectrum of the constant rotating field. We find interference effects not only in the momentum spectrum but also in the total particle number of rotating electric fields.
Relativistic tunneling picture of electron-positron pair creation
Anton Wöllert; Michael Klaiber; Heiko Bauke; Christoph H. Keitel
2015-03-19
The common tunneling picture of electron-positron pair creation in a strong electric field is generalized to pair creation in combined crossed electric and magnetic fields. This enhanced picture, being symmetric for electrons and positrons, is formulated in a gauge-invariant and Lorentz-invariant manner for quasistatic fields. It may be used to infer qualitative features of the pair creation process. In particular, it allows for an intuitive interpretation of how the presence of a magnetic field modifies and, in particular cases, even enhances pair creation. The creation of electrons and positrons from the vacuum may be assisted by an energetic photon, which can also be incorporated into this picture of pair creation.
Neutron-proton pairing correlations in odd mass systems
Fellah, M. Allal, N. H.; Oudih, M. R.
2015-03-30
An expression of the ground-state which describes odd mass systems within the BCS approach in the isovector neutron-proton pairing case is proposed using the blocked level technique. The gap equations as well as the energy expression are then derived. It is shown that they exactly generalize the expressions obtained in the pairing between like-particles case. The various gap parameters and the energy are then numerically studied as a function of the pairing-strength within the schematic one-level model.
Photon-pair generation in random nonlinear layered structures
Jan Perina Jr; Marco Centini; Concita Sibilia; Mario Bertolotti
2009-08-25
Nonlinearity and sharp transmission spectra of random 1D nonlinear layered structures are combined together to produce photon pairs with extremely narrow spectral bandwidths. Indistinguishable photons in a pair are nearly unentangled. Also two-photon states with coincident frequencies can be conveniently generated in these structures if photon pairs generated into a certain range of emission angles are superposed. If two photons are emitted into two different resonant peaks, the ratio of their spectral bandwidths may differ considerably from one and two photons remain nearly unentangled.
Pairs Emission in a Uniform Background Field: an Algebraic Approach
Roberto Soldati
2011-06-23
A fully algebraic general approach is developed to treat the pairs emission and absorption in the presence of some uniform external background field. In particular, it is shown that the pairs production and annihilation operators, together with the pairs number operator, do actually fulfill the SU(2) functional Lie algebra. As an example of application, the celebrated Schwinger formula is consistently and nicely recovered, within this novel approach, for a Dirac spinor field in the presence of a constant and homogeneous electric field in four spacetime dimensions.
Effective field theory for dilute fermions with pairing
Furnstahl, R.J. [Department of Physics, Ohio State University, Columbus, OH 43210 (United States)], E-mail: furnstahl.1@osu.edu; Hammer, H.-W. [Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie), Universitaet Bonn, Nussallee 14-16, D-53115 Bonn (Germany)], E-mail: hammer@itkp.uni-bonn.de; Puglia, S.J. [SBIG PLC, Berkeley Square House, London W1J 6BR (United Kingdom)], E-mail: spuglia@sbiguk.com
2007-11-15
Effective field theory (EFT) methods for a uniform system of fermions with short-range, natural interactions are extended to include pairing correlations, as part of a program to develop a systematic Kohn-Sham density functional theory (DFT) for medium and heavy nuclei. An effective action formalism for local composite operators leads to a free-energy functional that includes pairing by applying an inversion method order by order in the EFT expansion. A consistent renormalization scheme is demonstrated for the uniform system through next-to-leading order, which includes induced-interaction corrections to pairing.
Chiral three-nucleon forces and pairing in nuclei
Lesinski, Thomas; Hebeler, K.; Duguet, Thomas C; Schwenk, Achim
2012-01-01
We present the first study of pairing in nuclei including three-nucleon forces. We perform systematic calculations of the odd-even mass staggering generated using a microscopic pairing interaction at first order in chiral low-momentum interactions. Significant repulsive contributions from the leading chiral three-nucleon forces are found. Two- and three-nucleon interactions combined account for approximately 70% of the experimental pairing gaps, which leaves room for self-energy and induced interaction effects that are expected to be overall attractive in nuclei.
Stress-free BCS pairing in color superconductors is impossible
Krishna Rajagopal; Andreas Schmitt
2006-10-26
Cold, asymptotically dense three-flavor quark matter is in the color-flavor locked (CFL) phase, in which all quarks pair in a particularly symmetric fashion. At smaller densities, taking into account a nonzero strange quark mass and electric and color neutrality, the CFL phase requires pairing of quarks with mismatched Fermi momenta. We present a classification of all other possible, less symmetric, pairing patterns and prove that none of them can avoid this mismatch. This result suggests unconventional, e.g., spatially inhomogeneous, superconducting phases for moderate densities.
Two-dimensional simulations of pulsational pair-instability supernovae...
Office of Scientific and Technical Information (OSTI)
thermonuclear outbursts due to a recurring pair-instability. In some of these events, solar masses of material are ejected in repeated outbursts of several 10sup 50 erg...
Single-Pair FRET Characterization of DNA Tweezers
Ludwig-Maximilians-Universität, München
Single-Pair FRET Characterization of DNA Tweezers Barbara K. Mu1ller, Andreas Reuter, Friedrich C-Champaign, 1110 West Green Street, Urbana, Illinois 61801 Received August 18, 2006; Revised Manuscript Received
Emission of neutrino-antineutrino pairs by hadronic bremsstrahlung processes
Bacca, Sonia; Schwenk, Achim
2015-01-01
We review our recent calculations of neutrino-antineutrino pair production from bremsstrahlung processes in hadronic collisions at temperature and densities relevant for core-collapse supernovae. We focus on neutron-neutron and neutron-alpha collisions.
MENTORING PAIRINGS (plus others with mentors in common)
May, J. Peter
-mails, and mentors. (All e-mails are @midway.uchicago.edu.) Philip Ascher pa7 Fowler, Scheels, and Iyer Emil Bojanov and Patel Emily Witt emily1 Amin and Patel #12;MENTORING PAIRINGS 3 SESAME Graduate students and e
Measurement of the top quark pair production cross section in...
Office of Scientific and Technical Information (OSTI)
Measurement of the top quark pair production cross section in proton-proton collisions at sqrts13 TeV Citation Details In-Document Search Title: Measurement of the top quark...
Monojet plus soft dilepton signal from light higgsino pair production...
Office of Scientific and Technical Information (OSTI)
Monojet plus soft dilepton signal from light higgsino pair production at LHC14 Citation Details In-Document Search This content will become publicly available on December 8, 2015...
The Nuclear Pairing Gap -- How Low Can It Go?
B. Alex Brown
2013-08-16
The pairing gap for $^{53}$Ca obtained from new experimental data on the masses of $^{52-54}$Ca has the smallest value yet observed. This is explained in the framework of the nuclear shell model with schematic and realistic Hamiltonians as being due to shell gaps around the low-$ j $ orbital $ 1p_{1/2} $. Minima in the pairing gaps for all nuclei are shown and discussed
Possibility of Pairing-Induced Even-Denominator Fractional Quantum
Scarola, Vito
fermions (CFs) B* = B 2p0 Effective Field = 0 / B * = 0 / |B*| } = */(2p * 1)+- Effective Filling at = 5/2 ( Willett et. al. '87, Pan et. al `99) Novel p-wave paired state of CFs at = 5/2 : Electrons transform into CFs and pair up to yield a gap and hence FQHE MR = (zj -zk) 2 Pf[ (zj - zk) -1] (Moore, Read
Prolific pair production with high-power lasers
Bell, A R
2008-01-01
Prolific electron-positron pair production is possible at laser intensities approaching 10^{24} W/cm^2 at a wavelength of 1 micron. An analysis of electron trajectories and interactions at the nodes (B=0) of two counter-propagating, circularly polarised laser beams shows that a cascade of gamma-rays and pairs develops. The geometry is generalised qualitatively to linear polarisation and laser beams incident on a solid target.
Prolific pair production with high-power lasers
A. R. Bell; John G. Kirk
2008-10-16
Prolific electron-positron pair production is possible at laser intensities approaching 10^{24} W/cm^2 at a wavelength of 1 micron. An analysis of electron trajectories and interactions at the nodes (B=0) of two counter-propagating, circularly polarised laser beams shows that a cascade of gamma-rays and pairs develops. The geometry is generalised qualitatively to linear polarisation and laser beams incident on a solid target.
Randomly poled crystals as a source of photon pairs
Jan Perina Jr; Jiri Svozilik
2011-01-04
Generation of photon pairs from randomly poled nonlinear crystals is investigated using analytically soluble model and numerical calculations. Randomly poled crystals are discovered as sources of entangled ultra broad-band signal and idler fields. Their photon-pair generation rates scale linearly with the number of domains. Entanglement times as short as several fs can be reached. Comparison with chirped periodically-poled structures is given and reveals close similarity.
Formation of Cooper pairs as a consequence of exchange interaction
Stanislav Dolgopolov
2015-04-13
The pairing of two electrons with antiparallel spins may minimize the energy of each of the paired electrons. Thus the exchange interaction and the Pauli Exclusion Principle cause a bond between two electrons in a crystal. This can be proved analyzing the energy of each conduction electron in the field of a crystal on assumption that all other kinds of magnetic spin ordering in the crystal are weak. The superconductivity in a metallic crystal occurs only if conduction electrons before the pairing are put closely on the Fermi surface in the momentum space. The motion of conduction electrons in the crystal may disturb the formation of Cooper pairs, because the kinetic energy of the motion is usually much larger than the energy gap of superconductor. The conduction electrons as standing waves have a zero momentum, hence their momentums are synchronous; consequently the formation of Cooper pairs is more probable than in case of electrons with nonzero momentums. The total momentum of the pair of two electrons as standing waves is zero.
Pair-instability supernovae in the local universe
Whalen, Daniel J. [Zentrum für Astronomie, Institut für Theoretische Astrophysik, Universität Heidelberg, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Smidt, Joseph [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Victoria 3800 (Australia); Hirschi, Raphael [Astrophysics Group, EPSAM, University of Keele, Lennard-Jones Labs, Keele ST5 5BG (United Kingdom); Yusof, Norhasliza [Department of Physics, University of Malaysia, 50603 Kuala Lampur (Malaysia); Even, Wesley; Fryer, Chris L. [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Stiavelli, Massimo [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Chen, Ke-Jung [Department of Astronomy and Astrophysics, UCSC, Santa Cruz, CA 95064 (United States); Joggerst, Candace C. [XTD-3, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2014-12-10
The discovery of 150-300 M {sub ?} stars in the Local Group and pair-instability supernova candidates at low redshifts has excited interest in this exotic explosion mechanism. Realistic light curves for pair-instability supernovae at near-solar metallicities are key to identifying and properly interpreting these events as more are found. We have modeled pair-instability supernovae of 150-500 M {sub ?} Z ? 0.1-0.4 Z {sub ?} stars. These stars lose up to 80% of their mass to strong line-driven winds and explode as bare He cores. We find that their light curves and spectra are quite different from those of Population III pair-instability explosions, which therefore cannot be used as templates for low-redshift events. Although non-zero metallicity pair-instability supernovae are generally dimmer than their Population III counterparts, in some cases they will be bright enough to be detected at the earliest epochs at which they can occur, the formation of the first galaxies at z ? 10-15. Others can masquerade as dim, short duration supernovae that are only visible in the local universe and that under the right conditions could be hidden in a wide variety of supernova classes. We also report for the first time that some pair-instability explosions can create black holes with masses of ?100 M {sub ?}.
On magnon mediated Cooper pair formation in ferromagnetic superconductors
Kar, Rakesh; Paul, Bikash Chandra [Department of Physics, University of North Bengal, Raja Rammohunpur, Darjeeling 734013, West Bengal (India); Goswami, Tamal; Misra, Anirban, E-mail: anirbanmisra@yahoo.com [Department of Chemistry, University of North Bengal, Raja Rammohunpur, Darjeeling 734013, West Bengal (India)
2014-08-15
Identification of pairing mechanism leading to ferromagnetic superconductivity is one of the most challenging issues in condensed matter physics. Although different models have been proposed to explain this phenomenon, a quantitative understanding about this pairing is yet to be achieved. Using the localized-itinerant model, we find that in ferromagnetic superconducting materials both triplet pairing and singlet pairing of electrons are possible through magnon exchange depending upon whether the Debye cut off frequency of magnons is greater or lesser than the Hund's coupling (J) multiplied by average spin (S) per site. Taking into account the repulsive interaction due to the existence of paramagnons, we also find an expression for effective interaction potential between a pair of electrons with opposite spins. We apply the developed formalism in case of UGe{sub 2} and URhGe. The condition of singlet pairing is found to be fulfilled in these cases, as was previously envisaged by Suhl [Suhl, Phys. Rev. Lett. 87, 167007 (2001)]. We compute the critical temperatures of URhGe at ambient pressure and of UGe{sub 2} under different pressures for the first time through BCS equation. Thus, this work outlines a very simple way to evaluate critical temperature in case of a superconducting system. A close match with the available experimental results strongly supports our theoretical treatment.
THE TRUE COST OF PAIR PROGRAMMING: DEVELOPMENT OF A COMPREHENSIVE MODEL AND TEST
Sun, Wenying
2011-09-19
To advance the nomological net and theory, this dissertation proposed a comprehensive pair programming research model where the relationships among system complexity, programming methods, pair composition, effort, duration, ...
Polarization operator approach to pair creation in short laser pulses
Sebastian Meuren; Karen Z. Hatsagortsyan; Christoph H. Keitel; Antonino Di Piazza
2015-01-28
Short-pulse effects are investigated for the nonlinear Breit-Wheeler process, i.e. the production of an electron-positron pair induced by a gamma photon inside an intense plane-wave laser pulse. To obtain the total pair-creation probability we verify (to leading-order) the cutting rule for the polarization operator in the realm of strong-field QED by an explicit calculation. Using a double-integral representation for the leading-order contribution to the polarization operator, compact expressions for the total pair-creation probability inside an arbitrary plane-wave background field are derived. Correspondingly, the photon wave function including leading-order radiative corrections in the laser field is obtained via the Schwinger-Dyson equation in the quasistatic approximation. Moreover, the influence of the carrier-envelope phase and of the laser pulse shape on the total pair-creation probability in a linearly polarized laser pulse is investigated, and the validity of the (local) constant-crossed field approximation analyzed. It is shown that with presently available technology pair-creation probabilities of the order of ten percent could be reached for a single gamma photon.
Modulated pair condensate of p-orbital ultracold fermions
Zhang Zixu; Zhao Erhai; Liu, W. Vincent; Hung, Hsiang-Hsuan; Ho, Chiu Man
2010-09-15
We show that an interesting kind of pairing occurs for spin-imbalanced Fermi gases under a specific experimental condition--the spin up and spin down Fermi levels lying within the p{sub x} and s orbital bands of an optical lattice, respectively. The pairs condense at a finite momentum equal to the sum of the two Fermi momenta of spin up and spin down fermions and form a p-orbital pair condensate. This 2k{sub F} momentum dependence has been seen before in spin- and charge-density waves, but it differs from the usual p-wave superfluids such as {sup 3}He, where the orbital symmetry refers to the relative motion within each pair. Our conclusion is based on the density matrix renormalization group analysis for the one-dimensional (1D) system and mean-field theory for the quasi-1D system. The phase diagram of the quasi-1D system is calculated, showing that the p-orbital pair condensate occurs in a wide range of fillings. In the strongly attractive limit, the system realizes an unconventional BEC beyond Feynman's no-node theorem. The possible experimental signatures of this phase in molecule projection experiment are discussed.
Spices form the basis of food pairing in Indian cuisine
Jain, Anupam; Bagler, Ganesh
2015-01-01
Culinary practices are influenced by climate, culture, history and geography. Molecular composition of recipes in a cuisine reveals patterns in food preferences. Indian cuisine encompasses a number of diverse sub-cuisines separated by geographies, climates and cultures. Its culinary system has a long history of health-centric dietary practices focused on disease prevention and promotion of health. We study food pairing in recipes of Indian cuisine to show that, in contrast to positive food pairing reported in some Western cuisines, Indian cuisine has a strong signature of negative food pairing; more the extent of flavor sharing between any two ingredients, lesser their co-occurrence. This feature is independent of recipe size and is not explained by ingredient category-based recipe constitution alone. Ingredient frequency emerged as the dominant factor specifying the characteristic flavor sharing pattern of the cuisine. Spices, individually and as a category, form the basis of ingredient composition in Indian...
Investigation on collisions of filament pairs in dielectric barrier discharge
Dong, Lifang; Zhang, Chao; Li, Ben; Zhang, Xinpu; He, Yafeng; Li, Xuechen; Hebei Key Laboratory of Optic-electronic Information Materials, Baoding 071002
2013-12-15
Collisions of filament pairs in a hexagonal superlattice pattern in dielectric barrier discharge are investigated on different timescales. In the evolution of the pattern, the space scale of each hexagon cell decreases with the increasing voltage. The duration of one collision is seven half voltage cycles at least. Two stable orientations of a pair are approximately perpendicular to each other and the orientational changes occurring during the entire colliding process should be a multiple of 30°. The time interval between two consecutive collisions decreases with the increasing voltage. The distance between the paired spots decreases nonmonotonically. Based on the discharge order of the pattern, it is inferred that the collision should be the interaction between a discharging filament and the surface charges deposited by another discharged filament, and the nonmonotonic decrease of distance D is explained.
Rotation Rate of Particle Pairs in Homogeneous Isotropic Turbulence
Daddi-Moussa-Ider, Abdallah
2015-01-01
Understanding the dynamics of particles in turbulent flow is important in many environmental and industrial applications. In this paper, the statistics of particle pair orientation is numerically studied in homogeneous isotropic turbulent flow, with Taylor microscale Rynolds number of 300. It is shown that the Kolmogorov scaling fails to predict the observed probability density functions (PDFs) of the pair rotation rate and the higher order moments accurately. Therefore, a multifractal formalism is derived in order to include the intermittent behavior that is neglected in the Kolmogorov picture. The PDFs of finding the pairs at a given angular velocity for small relative separations, reveals extreme events with stretched tails and high kurtosis values. Additionally, The PDFs are found to be less intermittent and follow a complementary error function distribution for larger separations.
Effect of pairing on transfer and fusion reactions
Scamps, Guillaume
2014-01-01
In the present contribution, the effect of pairing on nuclear transfer and fusion reactions close to the Coulomb barrier is discussed. A Time-Dependent Hartree-Fock + BCS (TDHF+BCS) microscopic theory has been developed to incorporate pairing. One- and two-particle transfer probabilities can be obtained showing the importance of pairing. The calculated transfer probabilities are compared to the recent experimental results obtained for the $^{96}$Zr+$^{40}$Ca. Reactions involving the $^{18}$O with lead isotopes are also presented, that are also of current experimental interest. Finally, a study of the fusion barrier height predicted with the TDHF+BCS theory is compared to the experimental values for the $^{40,44,48}$Ca+$^{40}$Ca reactions.
Pair Winds in Schwarzschild Spacetime with Application to Strange Stars
A. G. Aksenov; M. Milgrom; V. V. Usov
2007-01-09
We present the results of numerical simulations of stationary, spherically outflowing, electron-positron pair winds, with total luminosities in the range 10^{34}--10^{42} ergs/s. In the concrete example described here, the wind injection source is a hot, bare, strange star, predicted to be a powerful source of pairs created by the Coulomb barrier at the quark surface. We find that photons dominate in the emerging emission, and the emerging photon spectrum is rather hard and differs substantially from the thermal spectrum expected from a neutron star with the same luminosity. This might help distinguish the putative bare strange stars from neutron stars.
A pair spectrometer for measuring multipolarities of energetic nuclear transitions
Gulyás, J; Krasznahorkay, A J; Csatlós, M; Csige, L; Gácsi, Z; Hunyadi, M; Krasznahorkay, A; Vitéz, A; Tornyi, T G
2015-01-01
A multi-detector array has been designed and constructed for the simultaneous measurement of energy- and angular correlations of electron-positron pairs. Experimental results are obtained over a wide angular range for high-energy transitions in 16O, 12C and 8Be. A comparison with GEANT simulations demonstrates that angular correlations between 50 and 180 degrees of the electron-positron pairs in the energy range between 6 and 18 MeV can be determined with sufficient resolution and efficiency.
Error-prevention scheme with two pairs of qubits
Chu, Shih-I; Yang, Chui-Ping; Han, Siyuan
2002-09-04
Ei jue ie j&5ue je i& , e iP$0,1% @6#!. The expressions for HS and HSB are as follows: HS5e0~s I z 1s II z !, *Email address: cpyang@floquet.chem.ku.edu †Email address: sichu@ku.edu ‡ Email address: han@ku.eduError-prevention scheme Chui-Ping Yang.... The sche two pairs of qubits and through error-prevention proc through a decoherence-free subspace for collective p pairs; leakage out of the encoding space due to amp addition, how to construct decoherence-free states for n discussed. DOI: 10.1103/Phys...
Measurements of the Top Quark Pair-Production Cross Section
Frank-Peter Schilling
2013-02-19
Measurements of the inclusive and differential cross section for the production of top quark pairs in proton-(anti)proton collision at center-of-mass energies of 1.96, 7.0 and 8.0 TeV are presented and compared with the latest theory predictions and Monte-Carlo models. In addition, first measurements of the production of top quark pairs in association with additional jets or with a boson are highlighted. All measurements are in good agreement with the Standard Model.
Gomez-Ceballos, Guillelmo
We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We consider both nonresonant ...
Phenotypic assortative mating and within-pair sexual dimorphism and its influence on breeding
Donázar, José A.
Phenotypic assortative mating and within-pair sexual dimorphism and its influence on breeding. Bertellotti, and O. Ceballos Abstract: We examined within-pair sexual dimorphism and phenotypic assortative to relate the body size of each member of the pair and the degree of sexual dimorphism within pairs
Role of Angular Electron Pair Correlation in Stabilizing C60
Simons, Jack
then combine to trap electrons of singlet C60 2 from detaching, thus producing the very long observed lifetimes with its long lifetime resulting from the need for an electron to tunnel through a barrier to undergoRole of Angular Electron Pair Correlation in Stabilizing C60 2 SETH DIFLEY, JACK SIMONS Department
Abstract polymer models with general pair interactions Aldo Procacci
Procacci, Aldo
Abstract polymer models with general pair interactions Aldo Procacci Dep. MatemÂ´atica-ICEx, UFMG (i.e. not necessarily hard core or repulsive). A concrete example is given in which polymers are r0 (possibly attractive), of the type 1/rd+ with > 0. 1. Introduction The abstract polymer gas is an important
Transition maps between the 24 bases for a Leonard pair
Nomura, Kazumasa
2007-01-01
Let $V$ denote a vector space with finite positive dimension. We consider a pair of linear transformations $A : V \\to V$ and $A^* : V \\to V$ that satisfy (i) and (ii) below: (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is irreducible tridiagonal and the matrix representing $A^*$ is diagonal. (ii) There exists a basis for $V$ with respect to which the matrix representing $A^*$ is irreducible tridiagonal and the matrix representing $A$ is diagonal. We call such a pair a Leonard pair on $V$. In an earlier paper we described 24 special bases for $V$. One feature of these bases is that with respect to each of them the matrices that represent $A$ and $A^*$ are (i) diagonal and irreducible tridiagonal or (ii) irreducible tridiagonal and diagonal or (iii) lower bidiagonal and upper bidiagonal or (iv) upper bidiagonal and lower bidiagonal. For each ordered pair of bases among the 24, there exists a unique linear transformation from $V$ to $V$ that sends the first basis to the seco...
Pair potential for FeHe N. Juslin *, K. Nordlund
Nordlund, Kai
formation and migration. Ab initio data for short range FeHe dimer interaction is used to describe the high collision cascades have been extensively studied with MD simulations to determine primary damage formation shows that a pair potential is enough to describe simple He defects and migration of He in iron
Creation and pinning of vortex-antivortex pairs
Kim, Sangbum; Hu, Chia-Ren; Andrews, Malcolm J.
2006-01-01
in a superconducting thin film, due to the magnetic field of a vertical magnetic dipole above the film, and two antidot pins inside the film. For film thickness =0.1 xi, kappa=2, and no pins, we find the film carries two V-AV pairs at steady state...
Singlet Free Energies of a Static Quark-Antiquark Pair
Konstantin Petrov
2004-09-01
We study the singlet part of the free energy of a static quark anti-quark pair at finite temperature in three flavor QCD with degenerate quark masses using $N_{\\tau}=4$ and 6 lattices with Asqtad staggered fermion action. We look at thermodynamics of the system around phase transition and study its scaling with lattice spacing and quark masses.
Pair spectrometer hodoscope for Hall D at Jefferson Lab
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Barbosa, Fernando J.; Hutton, Charles L.; Sitnikov, Alexandre; Somov, Alexander S.; Somov, S.; Tolstukhin, Ivan
2015-09-21
We present the design of the pair spectrometer hodoscope fabricated at Jefferson Lab and installed in the experimental Hall D. The hodoscope consists of thin scintillator tiles; the light from each tile is collected using wave-length shifting fibers and detected using a Hamamatsu silicon photomultiplier. Light collection was measured using relativistic electrons produced in the tagger area of the experimental Hall B.
Experimental Pair Trawling for Squid in New England
warps in front of the net to frighten the fish. Midwater and bottom pair trawl- ing for various fish an area of good squid catches. During this trip, two tows were made after dark. All other tows with only one warp from each boat leading to two 20-fathom bri- dles (legs) on each side of the net
BINARY STAR ORBITS. IV. ORBITS OF 18 SOUTHERN INTERFEROMETRIC PAIRS
Mason, Brian D.; Hartkopf, William I.; Tokovinin, Andrei E-mail: wih@usno.navy.mi
2010-09-15
First orbits are presented for 3 interferometric pairs and revised solutions for 15 others, based in part on first results from a recently initiated program of speckle interferometric observations of neglected southern binaries. Eight of these systems contain additional components, with multiplicity ranging up to 6.
Banded Matrix Fraction Representation of Triangular Input Normal Pairs
Banded Matrix Fraction Representation of Triangular Input Normal Pairs Andrew P. Mullhaupt #3 if and only if A is triangular and AA #3; + BB #3; = I n , where I n is the identity matrix. Input normal and A is a matrix fraction, A = M 1 N , where M and N are triangular matrices of low bandwidth. For single input
The Dependency Pair Framework: Combining Techniques for Automated Termination Proofs #
ÃbrahÃ¡m, Erika
The Dependency Pair Framework: Combining Techniques for Automated Termination Proofs # J of the most powerful techniques for automated termination proofs of term rewrite systems. Up to now of new methods for termination analyÂ sis. To demonstrate this, we present several new techniques within
Scaling security in pairing-based protocols Michael Scott
International Association for Cryptologic Research (IACR)
Scaling security in pairing-based protocols Michael Scott School of Computing Dublin City potential advantage in smart-card and embedded applications security can be scaled up while continuing been addressed by Koblitz and Menezes [18] and Granger, Page and Smart [15]. As will be seen our
Collapsibility of Lung Volume by Paired Inspiratory and Expiratory CT
Collapsibility of Lung Volume by Paired Inspiratory and Expiratory CT Scans: Correlations with Lung Function and Mean Lung Density Tsuneo Yamashiro, MD, Shin Matsuoka, MD, PhD, Brian J. Bartholmai, MD, Rau: To evaluate the relationship between measurements of lung volume (LV) on inspiratory/expiratory computed
A PLANAR PARALLEL MANIPULATOR WITH HOLONOMIC HIGHER PAIRS: INVERSE KINEMATICS
Hayes, John
kinematic analysis. Very little literature on such planar mechanisms was found. The e ects of initialA PLANAR PARALLEL MANIPULATOR WITH HOLONOMIC HIGHER PAIRS: INVERSE KINEMATICS Matthew John D. HAYES of Mechanical Engineering 817 r. Sherbrooke O., Rm 454, Montreal, Quebec, H3A 2K6 Canada, Tel: (514) 398
Bragg reflection waveguides as integrated sources of entangled photon pairs
to design an electrically pumped entangled photon source. © 2012 Optical Society of America OCIS codes: 230Bragg reflection waveguides as integrated sources of entangled photon pairs Sergei V. Zhukovsky,1 of Physics and Institute for Optical Sciences, University of Toronto, 60 St. George Street, Toronto, Ontario
Pair Instability Supernovae of Very Massive Population III Stars
Chen, Ke-Jung; Woosley, Stan; Almgren, Ann; Whalen, Daniel
2014-01-01
Numerical studies of primordial star formation suggest that the first stars in the universe may have been very massive. Stellar models indicate that non-rotating Population III stars with initial masses of 140-260 Msun die as highly energetic pair-instability supernovae. We present new two-dimensional simulations of primordial pair-instability supernovae done with the CASTRO code. Our simulations begin at earlier times than previous multidimensional models, at the onset of core collapse, to capture any dynamical instabilities that may be seeded by collapse and explosive burning. Such instabilities could enhance explosive yields by mixing hot ash with fuel, thereby accelerating nuclear burning, and affect the spectra of the supernova by dredging up heavy elements from greater depths in the star at early times. Our grid of models includes both blue supergiants and red supergiants over the range in progenitor mass expected for these events. We find that fluid instabilities driven by oxygen and helium burning ari...
Higgs pair production at the High Luminosity LHC
CMS Collaboration
2015-01-01
Studies of the Higgs boson pair production and decays into $bb\\gamma\\gamma$, $bb\\tau\\tau$, and $bb\\mathrm{W}\\mathrm{W}$ final states are presented. The studies are performed assuming the operational conditions of the High-Luminosity LHC, with an integrated luminosity of 3000~$\\mathrm{fb}^{-1}$, and the upgraded CMS experiment. Combining the studies of $bb\\gamma\\gamma$ and $bb\\tau\\tau$ final states, the expected significance for Higgs boson pair production is 1.9 standard deviation. The resulting expected uncertainty in the signal yield is $54\\%$. The benefits of the CMS Phase-II upgrade, to meet the challenges presented by the high luminosity environment, are emphasized.
Observation of ?c1 Decays into Vector Meson Pairs ??, ?? and, ??
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ablikim, M.; Achasov, M. N.; An, L.; An, Q.; An, Z. H.; Bai, J. Z.; Baldini, R.; Ban, Y.; Becker, J.; Berger, N.; et al
2011-08-22
Using (106±4)×10? ?(3686) events accumulated with the BESIII detector at the BEPCII e?e? collider, we present the first measurement of decays of ?c1 to vector meson pairs ??, ??, and ??. The branching fractions are measured to be (4.4±0.3±0.5)×10??, (6.0±0.3±0.7)×10??, and (2.2±0.6±0.2)×10??, for ?c1 ???, ??, and ??, respectively, which indicates that the hadron helicity selection rule is significantly violated in ?cJ decays. In addition, the measurement of ?cJ??? provides the first indication of the rate of doubly OZI-suppressed ?cJ decay. Finally, we present improved measurements for the branching fractions of ?c0 and ?c2 to vector meson pairs.
The Phoenix survey: the pairing fraction of faint radio sources
A. Georgakakis; B. Mobasher; L. Cram; A. Hopkins
1999-10-07
The significance of tidal interactions in the evolution of the faint radio population (sub-mJy) is studied using a deep and homogeneous radio survey (1.4 GHz), covering an area of 3.14 deg$^2$ and complete to a flux density of 0.4 mJy. Optical photometric and spectroscopic data are also available for this sample. A statistical approach is employed to identify candidate physical associations between radio sources and optically selected `field' galaxies. We find an excess of close pairs around optically identified faint radio sources, albeit at a low significance level, implying that the pairing fraction of the sub-mJy radio sources is similar to that of `field' galaxies (at the same magnitude limit) but higher than that of local galaxies.
Proton-neutron pairing energies in N=Z nuclei at finite temperature
K. Kaneko; M. Hasegawa
2005-08-27
Thermal behavior of isoscalar and isovector proton-neutron (pn) pairing energies at finite temperature are investigated by the shell model calculations. These pn pairing energies can be estimated by double differences of "thermal" energies which are extended from the double differences of binding energies as the indicators of pn pairing energies at zero temperature. We found that the delicate balance between isoscalar and isovector pn pairing energies at zero temperature disappears at finite temperature. When temperature rises, while the isovector pn pairing energy decreases, the isoscalar pn pairing energy rather increases. We discuss also the symmetry energy at finite temperature.
Fourier Transform Pairs The Fourier transform transforms a function of
Masci, Frank
Fourier Transform Pairs The Fourier transform transforms a function of time, f(t), into a function of frequency, F(s): F {f(t)}(s) = F(s) = Z - f(t)e- j2st dt. The inverse Fourier transform transforms a func. The inverse Fourier transform of the Fourier trans- form is the identity transform: f(t) = Z - Z - f()e- j2s
Calculations of pair production by Monte Carlo methods
Bottcher, C.; Strayer, M.R.
1991-01-01
We describe some of the technical design issues associated with the production of particle-antiparticle pairs in very large accelerators. To answer these questions requires extensive calculation of Feynman diagrams, in effect multi-dimensional integrals, which we evaluate by Monte Carlo methods on a variety of supercomputers. We present some portable algorithms for generating random numbers on vector and parallel architecture machines. 12 refs., 14 figs.
Brane tunneling and virtual brane-antibrane pairs
Adam R. Brown
2007-09-24
We survey barrier penetration by quantum tunneling for four cases: nonrelativistic point particles, scalar fields, relativistic point particles, and DBI branes. We examine two novel features that arise for DBI brane tunneling: the rate can sometimes increase as the barrier gets higher; and the instanton "wrinkles". We show that these features can be understood as the effect of the quantum sea of virtual brane-antibrane pairs. This sea exponentially augments the decay rate, with possible cosmological consequences.
Sedimentation of pairs of hydrodynamically interacting semiflexible filaments
Isaac Llopis; Ignacio Pagonabarraga; Marco Cosentino Lagomarsino; Christopher P. Lowe
2007-10-08
We describe the effect of hydrodynamic interactions in the sedimentation of a pair of inextensible semiflexible filaments under a uniform constant force at low Reynolds numbers. We have analyzed the different regimes and the morphology of such polymers in simple geometries, which allow us to highlight the peculiarities of the interplay between elastic and hydrodynamic stresses. Cooperative and symmetry breaking effects associated to the geometry of the fibers gives rise to characteristic motion which give them distinct properties from rigid and elastic filaments.
Double Pair Production by Ultra High Energy Cosmic Ray Photons
S. V. Demidov; O. E. Kalashev
2008-12-22
With use of CompHEP package we've made the detailed estimate of the influence of double e+e- pair production by photons (DPP) on the propagation of ultra high energy electromagnetic cascade. We show that in the models in which cosmic ray photons energy reaches few thousand EeV refined DPP analysis may lead to substantial difference in predicted photon spectrum compared to previous rough estimates.
Equilibrium cluster fluids: Pair interactions via inverse design
Ryan B. Jadrich; Jonathan A. Bollinger; Beth A. Lindquist; Thomas M. Truskett
2015-09-14
Inverse methods of statistical mechanics are becoming productive tools in the design of materials with specific microstructures or properties. While initial studies have focused on solid-state design targets (e.g, assembly of colloidal superlattices), one can alternatively design fluid states with desired morphologies. This work addresses the latter and demonstrates how a simple iterative Boltzmann inversion strategy can be used to determine the isotropic pair potential that reproduces the radial distribution function of a fluid of amorphous clusters with prescribed size. The inverse designed pair potential of this "ideal" cluster fluid, with its broad attractive well and narrow repulsive barrier at larger separations, is qualitatively different from the so-called SALR form most commonly associated with equilibrium cluster formation in colloids, which features short-range attractive (SA) and long-range repulsive (LR) contributions. These differences reflect alternative mechanisms for promoting cluster formation with an isotropic pair potential, and they in turn produce structured fluids with qualitatively different static and dynamic properties. Specifically, equilibrium simulations show that the amorphous clusters resulting from the inverse designed potentials display more uniformity in size and shape, and they also show greater spatial and temporal resolution than those resulting from SALR interactions.
Coulomb pairing resonances in multiple-ring aromatic molecules
Huber, D L
2015-01-01
We present an analysis of the Coulomb pairing resonances observed in photo-double-ionization studies of CnHm aromatic molecules with multiple benzene-like rings. It is applied to naphthalene, anthracene, phenanthrene, pyrene and coronene, all of which have six-member rings, and azulene which is comprised of a five-member and a seven-member ring. There is a high energy resonance at ~ 40 eV that is found in all of the molecules cited and is associated with paired electrons localized on carbon sites on the perimeter of the molecule, each of which having two carbon sites as nearest neighbors. The low energy resonance at 10 eV, which is found only in pyrene and coronene, is attributed to the formation of paired electrons localized on arrays of interior carbon atoms that have the point symmetry of the molecule with each carbon atom having three nearest neighbors. The origin of the anomalous increase in the doubly charged to singly charged parent-ion ratio that is found above the 40 eV resonance in all of the cited ...
Physics of base-pairing dynamics in DNA
Manoel Manghi; Nicolas Destainville
2015-10-19
As a key molecule of Life, Deoxyribonucleic acid (DNA) is the focus of numbers of investigations with the help of biological, chemical and physical techniques. From a physical point of view, both experimental and theoretical works have brought quantitative insights into DNA base-pairing dynamics that we review in this Report, putting emphasis on theoretical developments. We discuss the dynamics at the base-pair scale and its pivotal coupling with the polymer one, with a polymerization index running from a few nucleotides to tens of kilo-bases. This includes opening and closure of short hairpins and oligomers as well as zipping and unwinding of long macromolecules. We review how different physical mechanisms are either used by Nature or utilized in biotechnological processes to separate the two intertwined DNA strands, by insisting on quantitative results. They go from thermally-assisted denaturation bubble nucleation to force- or torque- driven mechanisms. We show that the helical character of the molecule, possibly supercoiled, can play a key role in many denaturation and renaturation processes. We categorize the mechanisms according to the relative timescales associated with base-pairing and chain degrees of freedom such as bending and torsional elastic ones. In some specific situations, these chain degrees of freedom can be integrated out, and the quasi- static approximation is valid. The complex dynamics then reduces to the diffusion in a low-dimensional free-energy landscape. In contrast, some important cases of experimental interest necessarily appeal to far-from-equilibrium statistical mechanics and hydrodynamics.
HBT interferometry with quantum transport of the interfering pair
Yu, Li-Li; Wong, Cheuk-Yin
2008-01-01
In the late stage of the evolution of a pion system in high-energy heavy-ion collisions when pions undergo multiple scatterings, the quantum transport of the interfering pair of identical pions plays an important role in determining the characteristics of the Hanbury-Brown-Twiss (HBT) interference. We study the quantum transport of the interfering pair using the path-integral method, in which the evolution of the bulk matter is described by relativistic hydrodynamics while the paths of the two interfering pions by test particles following the fluid positions and velocity fields. We investigate in addition the effects of secondary pion sources from particle decays, for nuclear collisions at AGS and RHIC energies. We find that quantum transport of the interfering pair leads to HBT radii close to those for the chemical freeze-out configuration. Particle decays however lead to HBT radii greater than those for the chemical freeze-out configuration. As a consequence, the combined effects give rise to HBT radii betw...
RG-Improved Predictions for Top-Quark Pair Production at
California at Santa Cruz, University of
RG-Improved Predictions for Top-Quark Pair Production at Hadron Colliders Matthias Neubert Johannes Threshold resummation for Higgs production Threshold resummation for top-quark pair production Valentin
NON-BIPARTITE PAIRS OF 3-CONNECTED GRAPHS ARE HIGHLY RAMSEY-INFINITE
Siggers, Mark H.
NON-BIPARTITE PAIRS OF 3-CONNECTED GRAPHS ARE HIGHLY RAMSEY-INFINITE MARK SIGGERS ABSTRACT. A pair of graphs (Hb,Hr) is highly Ramsey-infinite if there is some constant c such that for large enough n. We show that a pair of 3-connected graphs is highly Ramsey-infinite if and only if at least one
$J$-pairing Interactions of Fermions in a Single-$j$ Shell
A. Arima
2004-05-26
In this talk I shall introduce our recent works on general pairing interactions and pair truncation approximations for fermions in a single-j shell, including the spin zero dominance, features of eigenvalues of fermion systems in a single-j shell interacting by a $J-$pairing interaction.
Azevedo, Ricardo
of Refugees Job Description Houston-based Partnership for the Advancement & Immersion of Refugees (PAIR) (www volunteers serving more than 200 refugees per year, PAIR empowers refugee youth to reach their full potential in the community to foster an understanding of the needs of young refugees and the role of PAIR's programs
Hydrologic calibration of paired watersheds using a MOSUM approach
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ssegane, H.; Amatya, D. M.; Muwamba, A.; Chescheir, G. M.; Appelboom, T.; Tollner, E. W.; Nettles, J. E.; Youssef, M. A.; Birgand, F.; Skaggs, R. W.
2015-01-09
Paired watershed studies have historically been used to quantify hydrologic effects of land use and management practices by concurrently monitoring two neighboring watersheds (a control and a treatment) during the calibration (pre-treatment) and post-treatment periods. This study characterizes seasonal water table and flow response to rainfall during the calibration period and tests a change detection technique of moving sums of recursive residuals (MOSUM) to select calibration periods for each control-treatment watershed pair when the regression coefficients for daily water table elevation (WTE) were most stable to reduce regression model uncertainty. The control and treatment watersheds included 1–3 year intensively managedmore »loblolly pine (Pinus taeda L.) with natural understory, same age loblolly pine intercropped with switchgrass (Panicum virgatum), 14–15 year thinned loblolly pine with natural understory (control), and switchgrass only. Although monitoring during the calibration period spanned 2009 to 2012, silvicultural operational practices that occurred during this period such as harvesting of existing stand and site preparation for pine and switchgrass establishment may have acted as external factors, potentially shifting hydrologic calibration relationships between control and treatment watersheds. Results indicated that MOSUM was able to detect significant changes in regression parameters for WTE due to silvicultural operations. This approach also minimized uncertainty of calibration relationships which could otherwise mask marginal treatment effects. All calibration relationships developed using this MOSUM method were quantifiable, strong, and consistent with Nash–Sutcliffe Efficiency (NSE) greater than 0.97 for WTE and NSE greater than 0.92 for daily flow, indicating its applicability for choosing calibration periods of paired watershed studies.« less
Radiative emission of neutrino pair free of quantum electrodynamic backgrounds
M. Yoshimura; N. Sasao; M. Tanaka
2015-01-23
A scheme of quantum electrodynamic (QED) background-free radiative emission of neutrino pair (RENP) is proposed in order to achieve precision determination of neutrino properties so far not accessible. The important point for the background rejection is the fact that the dispersion relation between wave vector along propagating direction in wave guide (and in a photonic-crystal type fiber) and frequency is modified by a discretized non-vanishing effective mass. This effective mass acts as a cutoff of allowed frequencies, and one may select the RENP photon energy region free of all macro-coherently amplified QED processes by choosing the cutoff larger than the mass of neutrinos.
Photoproduction of electron-positron pairs in bent single crystals
Chesnokov, Yu A; Bolognini, D; Hasan, S; Prest, M; Vallazza, E
2010-01-01
The process of photoproduction of electron-positron pairs in bent single crystals is considered in this paper. In particular, it is shown that the probability of the process for gamma-quanta with energies from 100 GeV on is significantly higher than the one in an amorphous medium. A possible scenario for the experimental validation of the process is discussed and the positive features of the photoproduction in bent crystals compared to straight ones are underlined from the point of view of possible applications.
Infinitely many pairs of primes $p$ and $p+2$
Guangchang Dong
2015-03-20
When $p$ and $p+2$ are primes, such as $3,5; 5,7; 11,13; 17,19; ...$. We call them pairs of prime twins. In this paper we use sieve method (Liu sieve) to construct the weak solution (i.e. formal solution) of prime twins. Then we use auxiliary special 4 sieve problem and its biological model to prove that weak equals classical, i.e. the weak solution is a classical one, hence the numbers of prime twins are infinite.
Building Projected Entangled Pair States with a Local Gauge Symmetry
Erez Zohar; Michele Burrello
2015-11-26
Tensor network states, and in particular projected entangled pair states (PEPS), suggest an innovative approach for the study of lattice gauge theories, both from a pure theoretic point of view, and as a tool for the analysis of the recent proposals for quantum simulations of lattice gauge theories. In this paper we present a framework for describing locally gauge invariant states on lattices using PEPS. The PEPS constructed hereby shall include both bosonic and fermionic states, suitable for all combinations of matter and gauge fields in lattice gauge theories defined by either finite or compact Lie groups.
Automated Complexity Analysis Based on the Dependency Pair Method
Hirokawa, Nao
2011-01-01
This article is concerned with automated complexity analysis of term rewrite systems (TRSs for short). Since these systems underlie much of declarative programming, time complexity of functions defined by TRSs is of particular interest. Among other results, we present a variant of the dependency pair method for analysing runtime complexities of term rewrite systems automatically. The established results significantly extent previously known techniques: we give examples of TRSs subject to our methods that could previously not been analysed automatically. Furthermore, the techniques have been implemented in the Tyrolean Complexity Tool. We provide ample numerical data for assessing the viability of the method.
Lepton-pair production in nuclear collisions - past, present, future
H. J. Specht
2007-10-29
The key results on lepton-pair production in ultra-relativistic nuclear collisions are shortly reviewed, starting at the roots of pp collisions in the seventies, and ending at the perspectives of the colliders RHIC and LHC. The presence is dominated by the recent precision results from NA60 at the CERN SPS, culminating in the first measurement of the in-medium rho spectral function and the transverse flow of the associated thermal radiation. The seeming cut-off of the flow above the rho may well be the first direct hint for thermal radiation of partonic origin in nuclear collisions. The major milestones in the theoretical developments are also covered.
Seems a Fate in It: Misdirection and Foreshadowing in Bleak House and A Pair of Blue Eyes
Bradfield, Meredith
2013-01-01
for Action in A Pair of Blue Eyes. ” English Literature in2013). Hardy, Thomas. A Pair of Blue Eyes. Harmondsworth,aware of Thomas Hardy. A Pair of Blue Eyes. (Harmondsworth,
Hartree-Fock-Bogoliubov solution of the pairing Hamiltonian in finite nuclei
Dobaczewski, J
2012-01-01
We present an overview of the Hartree-Fock-Bogoliubov (HFB) theory of nucleonic superfluidity for finite nuclei. After introducing basic concepts related to pairing correlations, we show how the correlated pairs are incorporated into the HFB wave function. Thereafter, we present derivation and structure of the HFB equations within the superfluid nuclear density functional formalism and discuss several aspects of the theory, including the unitarity of the Bogoliubov transformation in truncated single-particle and quasiparticle spaces, form of the pairing functional, structure of the HFB continuum, regularization and renormalization of pairing fields, and treatment of pairing in systems with odd particle numbers.
Pair production of color-octet scalars at the LHC
Idilbi, Ahmad [Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Departamento de Fisica Teorica II, Universidad Complutense de Madrid, 28040 Madrid (Spain); Kim, Chul [Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Theory Division, Department of Physics, CERN, CH-1211, Geneva 23 (Switzerland); Mehen, Thomas [Department of Physics, Duke University, Durham, North Carolina 27708 (United States)
2010-10-01
Heavy colored scalar particles, which exist in many models of new physics, can be pair produced at the LHC via gluon-gluon fusion and possibly form quarkoniumlike bound states. If the scalars are also charged under the electroweak gauge group, these bound states can then decay into electroweak bosons. This yields a resonant cross section for final states such as {gamma}{gamma} that can exceed standard model backgrounds. This paper studies this process in the Manohar-Wise model of color-octet scalars (COS). Important threshold logarithms and final state Coulomb-like QCD interactions are resummed using effective field theory. We compute the resummed cross section for gluon-gluon fusion to COS pairs at the LHC as well as the resonant cross section for octetonium decaying to {gamma}{gamma}. The latter cross section exceeds the standard model diphoton cross section when the COS mass is less than 500 (350) GeV for {radical}(s)=14(7) TeV. Nonobservation of resonances below these energies can significantly improve existing bounds on COS masses.
FINDING THE FIRST COSMIC EXPLOSIONS. I. PAIR-INSTABILITY SUPERNOVAE
Whalen, Daniel J.; Smidt, Joseph; Lovekin, C. C. [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Even, Wesley; Fryer, Chris L. [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Frey, Lucille H. [HPC-3, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Johnson, Jarrett L.; Hungerford, Aimee L. [XTD-6, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Stiavelli, Massimo [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Holz, Daniel E. [Enrico Fermi Institute, Department of Physics, and Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Victoria 3800 (Australia); Woosley, S. E. [Department of Astronomy and Astrophysics, UCSC, Santa Cruz, CA 95064 (United States)
2013-11-10
The first stars are the key to the formation of primitive galaxies, early cosmological reionization and chemical enrichment, and the origin of supermassive black holes. Unfortunately, in spite of their extreme luminosities, individual Population III (Pop III) stars will likely remain beyond the reach of direct observation for decades to come. However, their properties could be revealed by their supernova explosions, which may soon be detected by a new generation of near-IR (NIR) observatories such as JWST and WFIRST. We present light curves and spectra for Pop III pair-instability supernovae calculated with the Los Alamos radiation hydrodynamics code RAGE. Our numerical simulations account for the interaction of the blast with realistic circumstellar envelopes, the opacity of the envelope, and Lyman absorption by the neutral intergalactic medium at high redshift, all of which are crucial to computing the NIR signatures of the first cosmic explosions. We find that JWST will detect pair-instability supernovae out to z ?> 30, WFIRST will detect them in all-sky surveys out to z ? 15-20, and LSST and Pan-STARRS will find them at z ?< 7-8. The discovery of these ancient explosions will probe the first stellar populations and reveal the existence of primitive galaxies that might not otherwise have been detected.
Creation of Electron Spinless Pairs in the Superconductivity
V. N. Minasyan
2009-03-28
First, it is demonstrated that the Froolich Hamiltonian of system in the superconductivity, proposed by the model of a phonon gas and an electron gas mixture, contains a subtle error. In this respect, we present a correct form of the Froolich Hamiltonian of system where the term of the interaction between the phonon modes and the density modes of the electron modes is described by the term of scattering, introduced by the Froolich in a phonon gas electron gas mixture. The later is removed by a canonical transformation of the Froolich Hamiltonian by an appearance of the attractive interaction mediated via the electron modes, which leads to a bound state on a spinless electron pairs. In this letter, we show that the Cooper approximation as the constancy of the density states within around of the Fermi level has a flaw because the effective attractive forces cannot create the Cooper pairs into energetic gap at the Fermi level. In this letter, we find a condition for density metal which determines metal as superconductor.
Top quark pair production and top quark properties at CDF
Chang-Seong Moon
2014-11-01
We present the most recent measurements of top quark pairs production and top quark properties in proton-antiproton collisions with center-of-mass energy of 1.96 TeV using CDF II detector at the Tevatron. The combination of top pair production cross section measurements and the direct measurement of top quark width are reported. The test of Standard Model predictions for top quark decaying into $b$-quarks, performed by measuring the ratio $R$ between the top quark branching fraction to $b$-quark and the branching fraction to any type of down quark is shown. The extraction of the CKM matrix element $|V_{tb}|$ from the ratio $R$ is discussed. We also present the latest measurements on the forward-backward asymmetry ($A_{FB}$) in top anti-top quark production. With the full CDF Run II data set, the measurements are performed in top anti-top decaying to final states that contain one or two charged leptons (electrons or muons). In addition, we combine the results of the leptonic forward-backward asymmetry in $t\\bar t$ system between the two final states. All the results show deviations from the next-to-leading order (NLO) standard model (SM) calculation.
Pair instability supernovae of very massive population III stars
Chen, Ke-Jung; Woosley, Stan [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Victoria 3800 (Australia); Almgren, Ann [Center for Computational Sciences and Engineering, Lawrence Berkeley National Lab, Berkeley, CA 94720 (United States); Whalen, Daniel J., E-mail: kchen@ucolick.org [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2014-09-01
Numerical studies of primordial star formation suggest that the first stars in the universe may have been very massive. Stellar models indicate that non-rotating Population III stars with initial masses of 140-260 M {sub ?} die as highly energetic pair-instability supernovae. We present new two-dimensional simulations of primordial pair-instability supernovae done with the CASTRO code. Our simulations begin at earlier times than previous multidimensional models, at the onset of core contraction, to capture any dynamical instabilities that may be seeded by core contraction and explosive burning. Such instabilities could enhance explosive yields by mixing hot ash with fuel, thereby accelerating nuclear burning, and affect the spectra of the supernova by dredging up heavy elements from greater depths in the star at early times. Our grid of models includes both blue supergiants and red supergiants over the range in progenitor mass expected for these events. We find that fluid instabilities driven by oxygen and helium burning arise at the upper and lower boundaries of the oxygen shell ?20-100 s after core bounce. Instabilities driven by burning freeze out after the SN shock exits the helium core. As the shock later propagates through the hydrogen envelope, a strong reverse shock forms that drives the growth of Rayleigh-Taylor instabilities. In red supergiant progenitors, the amplitudes of these instabilities are sufficient to mix the supernova ejecta.
Search for pair production of second generation scalar leptoquarks
Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahsan, M.; Alexeev, G.D.; Alkhazov, Georgiy D.; Alton, Andrew K.; /Michigan U. /Northeastern U.
2008-08-01
We report on a search for the pair production of second generation scalar leptoquarks (LQ) in p{bar p} collisions at the center of mass energy {radical}s = 1.96TeV using a data set corresponding to an integrated luminosity of 1.0 fb{sup -1} collected with the D0 experiment at the Fermilab Tevatron Collider. Topologies arising from the LQ{ovr LQ} {yields} {mu}q{nu}q and LQ{ovr LQ} {yields} {mu}q{mu}q decay modes are investigated. No excess of data over the standard model prediction is observed and upper limits on the leptoquark pair production cross section are derived at the 95% C.L. as a function of the leptoquark mass and the branching fraction {beta} for the decay LQ {yields} {mu}q. These are interpreted as lower limits on the leptoquark mass as a function of {beta}. For {beta} = 1 (0.5), scalar second generation leptoquarks with masses up to 316GeV (270GeV) are excluded.
State recovery and lockstep execution restart in a system with multiprocessor pairing
Gara, Alan; Gschwind, Michael K; Salapura, Valentina
2014-01-21
System, method and computer program product for a multiprocessing system to offer selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). Each paired microprocessor or processor cores that provide one highly reliable thread for high-reliability connect with a system components such as a memory "nest" (or memory hierarchy), an optional system controller, and optional interrupt controller, optional I/O or peripheral devices, etc. The memory nest is attached to a selective pairing facility via a switch or a bus. Each selectively paired processor core is includes a transactional execution facility, whereing the system is configured to enable processor rollback to a previous state and reinitialize lockstep execution in order to recover from an incorrect execution when an incorrect execution has been detected by the selective pairing facility.
Search for pair-produced resonances decaying to jet pairs in proton–proton collisions at ?s = 8 TeV
Apyan, Aram
Results are reported of a general search for pair production of heavy resonances decaying to pairs of hadronic jets in events with at least four jets. The study is based on up to 19.4 fb[superscript ?1] of integrated ...
Reduction in maximum time uncertainty of paired time signals
Theodosiou, G.E.; Dawson, J.W.
1981-02-11
Reduction in the maximum time uncertainty (t/sub max/ - t/sub min/) of a series of paired time signals t/sub 1/ and t/sub 2/ varying between two input terminals and representative of a series of single events where t/sub 1/ less than or equal to t/sub 2/ and t/sub 1/ + t/sub 2/ equals a constant, is carried out with a circuit utilizing a combination of OR and AND gates as signal selecting means and one or more time delays to increase the minimum value (t/sub min/) of the first signal t/sub 1/ closer to t/sub max/ and thereby reduce the difference. The circuit may utilize a plurality of stages to reduce the uncertainty by factors of 20 to 800.
Reconstructing particle masses from pairs of decay chains
Mihoko M. Nojiri; Kazuki Sakurai; Bryan R. Webber
2010-06-01
A method is proposed for determining the masses of the new particles N,X,Y,Z in collider events containing a pair of effectively identical decay chains Z to Y+jet, Y to X+l_1, X to N+l_2, where l_1, l_2 are opposite-sign same-flavour charged leptons and N is invisible. By first determining the upper edge of the dilepton invariant mass spectrum, we reduce the problem to a curve for each event in the 3-dimensional space of mass-squared differences. The region through which most curves pass then determines the unknown masses. A statistical approach is applied to take account of mismeasurement of jet and missing momenta. The method is easily visualized and rather robust against combinatorial ambiguities and finite detector resolution. It can be successful even for small event samples, since it makes full use of the kinematical information from every event.
Kaon pair production in proton-nucleus collisions
Yu. T. Kiselev; M. Hartmann; A. Polyanskiy; E. Ya. Paryev; S. Barsov; M. Buescher; S. Dymov; R. Gebel; V. Hejny; A. Kacharava; I. Keshelashvili; B. Lorentz; Y. Maeda; S. Merzliakov; S. Mikirtytchiants; H. Ohm; V. Serdyuk; A. Sibirtsev; V. Y. Sinitsyna; H. J. Stein; H. Stroeher; S. Trusov; Yu. Valdau; C. Wilkin; P. Wuestner; Q. J. Ye
2015-09-16
The production of non-phi K+K- pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets has been investigated using the COSY-ANKE magnetic spectrometer. The K- momentum dependence of the differential cross section has been measured at small angles over the 0.2--0.9 GeV/c range. The comparison of the data with detailed model calculations indicates an attractive K- -nucleus potential of about -60 MeV at normal nuclear matter density at a mean momentum of 0.5 GeV/c. However, this approach has difficulty in reproducing the smallness of the observed cross sections at low K- momenta.
Kaon pair production in proton-nucleus collisions
Kiselev, Yu T; Polyanskiy, A; Paryev, E Ya; Barsov, S; Buescher, M; Dymov, S; Gebel, R; Hejny, V; Kacharava, A; Keshelashvili, I; Lorentz, B; Maeda, Y; Merzliakov, S; Mikirtytchiants, S; Ohm, H; Serdyuk, V; Sibirtsev, A; Sinitsyna, V Y; Stein, H J; Stroeher, H; Trusov, S; Valdau, Yu; Wilkin, C; Wuestner, P; Ye, Q J
2015-01-01
The production of non-phi K+K- pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets has been investigated using the COSY-ANKE magnetic spectrometer. The K- momentum dependence of the differential cross section has been measured at small angles over the 0.2--0.9 GeV/c range. The comparison of the data with detailed model calculations indicates an attractive K- -nucleus potential of about -60 MeV at normal nuclear matter density at a mean momentum of 0.5 GeV/c. However, this approach has difficulty in reproducing the smallness of the observed cross sections at low K- momenta.
Valley pair qubits in double quantum dots of gapped graphene
G. Y. Wu; N. -Y. Lue; L. Chang
2011-07-03
The rise of graphene opens a new door to qubit implementation, as discussed in the recent proposal of valley pair qubits in double quantum dots of gapped graphene (Wu et al., arXiv: 1104.0443 [cond-mat.mes-hall]). The work here presents the comprehensive theory underlying the proposal. It discusses the interaction of electrons with external magnetic and electric fields in such structures. Specifically, it examines a strong, unique mechanism, i.e., the analogue of the 1st-order relativistic effect in gapped graphene. This mechanism is state mixing free and allows, together with the electrically tunable exchange coupling, a fast, all-electric manipulation of qubits via electric gates, in the time scale of ns. The work also looks into the issue of fault tolerance in a typical case, yielding at 10oK a long qubit coherence time (~O(ms)).
One-photon pair production on de Sitter spacetime
Blaga, Robert
2015-01-01
We study the one-photon scalar pair production QED process on the expanding de Sitter spacetime. Using perturbation theory, we obtain the transition probability and study its properties as a function of the expansion parameter $\\omega$. On flat space the process is forbidden by energy-momentum conservation. It is expected that for a dynamical background there is an energy exchange correlate to the strength of the gravitational field. We use momentum space plots and compute the mean production angle to illustrate this. We show that the mean angle grows with $\\omega$, but also find that in the flat limit the fall-off is unexpectedly slow. To investigate this further we obtain the probability around different angular configuration, at leading order in $m/\\omega$, and find that the $\\omega$ dependence at small angles is very weak. We comment on the possible astrophysical implications.
Pair creation in an electric flux tube and chiral anomaly
Iwazaki, Aiichi [International Economics and Politics, Nishogakusha University, Ohi Kashiwa, Chiba 277-8585 (Japan)
2009-11-15
Using the chiral anomaly, we discuss the pair creation of massless fermions under the effect of a magnetic field B-vector when an electric flux tube E-vector parallel to B-vector is switched on. The tube is axially symmetric and infinitely long. For the constraint B>>E, we can analytically obtain the spatial and temporal behaviors of the number density of the fermions, the azimuthal magnetic field generated by the fermions, and so on. We find that the lifetime t{sub c} of the electric field becomes shorter as the width of the tube becomes narrower. Applying it to the plasma in high-energy heavy-ion collisions, we find that the color electric field decays quickly such that t{sub c}{approx_equal}Q{sub s}{sup -1}, in which Q{sub s} is the saturation momentum.
Pairing Interaction in N=Z Nuclei with Half-filled High-j Shell
A. Juodagalvis
2000-04-21
The role of L=0 pairing interactions (both T=0 and T=1) in three selected bands with the total isospin T=0 in 22Na, 48Cr and 90Rh nuclei is discussed in the spherical shell model. These bands were selected requiring termination in a most unfavourable way. The investigated effects coming from pairing interactions include the change of nuclear wavefunction, quadrupole properties and state energy. To follow the gradual change of nuclear properties, the investigation is performed in a perturbative approach by defining the Hamiltonian with a variable content of the pairing interaction. It is shown that the pairing does not affect the quadrupole properties, if the energy distance to other close lying states is large. The calculated pairing energy is shown to have a similar spin dependence in these three bands. In addition, the influence of the model space as well as of the residual interaction on the derived pairing energy is discussed.
Photon-pair generation in nonlinear metal-dielectric 1D photonic structures
Dalibor Jav?rek; Jan Pe?ina Jr.; Ji?í Svozilík
2014-10-16
Nonlinear metal-dielectric layered structures are shown to be able to efficiently generate entangled photon pairs using spontaneous parametric down-conversion. Increase of electric-field amplitudes in these structures enhanced by the presence of metal layers is sufficient to compensate for losses inside thin metal layers. As an example, photon pairs emitted from a structure composed of alternating nonlinear dielectric GaN layers and metal Ag layers are analyzed in spectral, temporal as well as spatial domains. Also correlations and entanglement between two photons in a pair are determined. Very narrow photon-pair spectra together with strong directionality of photon-pair emission are observed making the photons suitable for photon-atom interactions. Highly enhanced electric-field amplitudes provide high photon-pair generation efficiencies.
Pairing effect in thermal shape fluctuation model on the width of giant dipole resonance
A. K. Rhine Kumar; P. Arumugam; N. Dinh Dang
2014-09-23
We present an approach that includes temperature-dependent shell effects and fluctuations of the pairing field in the thermal shape fluctuation model (TSFM). We apply this approach to study the width of giant dipole resonance (GDR) in $^{97}$Tc, $^{120}$Sn and $^{208}$Pb. Our results demonstrate that the TSFM that includes pairing fluctuations can explain the recently observed quenching in the GDR width. We also show that to validate pairing prescriptions and the parameters involved, we require more and precise data.
M. Hendrych; M. Mi?uda; A. Valencia; J. P. Torres
2009-08-13
We present an experimental demonstration of the full control of the frequency correlations of entangled photon pairs. The joint spectrum of photon pairs is continuously varied from photons that exhibit anticorrelation in frequency to photons that exhibit correlation in frequency, passing through the case of uncorrelated photons. Highly entangled frequency-anticorrelated photon pairs were obtained even when an ultrafast laser was used as a pump. The different kinds of correlations are obtained without changing neither the wavelength, nor the nonlinear crystal.
Pairing state with a time-reversal symmetry breaking in FeAs...
Office of Scientific and Technical Information (OSTI)
English Subject: 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COMPETITION; ELECTRONS; GINZBURG-LANDAU THEORY; HOLES; ORDER PARAMETERS; PAIRING INTERACTIONS; RESONANCE;...
Natural orbits of atomic Cooper pairs in a nonuniform Fermi gas
Y. H. Pong; C. K. Law
2006-05-08
We examine the basic mode structure of atomic Cooper pairs in an inhomogeneous Fermi gas. Based on the properties of Bogoliubov quasi-particle vacuum, the single particle density matrix and the anomalous density matrix share the same set of eigenfunctions. These eigenfunctions correspond to natural pairing orbits associated with the BCS ground state. We investigate these orbits for a Fermi gas in a spherical harmonic trap, and construct the wave function of a Cooper pair in the form of Schmidt decomposition. The issue of spatial quantum entanglement between constituent atoms in a pair is addressed.
Pair correlations in nuclei involved in neutrinoless double beta decay: 76Ge and 76Se
S. J. Freeman; J. P. Schiffer; A. C. C. Villari; J. A. Clark; C. Deibel; S. Gros; A. Heinz; D. Hirata; C. L. Jiang; B. P. Kay; A. Parikh; P. D. Parker; J. Qian; K. E. Rehm; X. D. Tang; V. Werner; C. Wrede
2007-03-23
Precision measurements were carried out to test the similarities between the ground states of 76Ge and 76Se. The extent to which these two nuclei can be characterized as consisting of correlated pairs of neutrons in a BCS-like ground state was studied. The pair removal (p,t) reaction was measured at the far forward angle of 3 degrees. The relative cross sections are consistent (at the 5% level) with the description of these nuclei in terms of a correlated pairing state outside the N=28 closed shells with no pairing vibrations. Data were also obtained for 74Ge and 78Se.
Xiaoying Li; Xiaoxin Ma; Limei Quan; Lei Yang; Liang Cui; Xueshi Guo
2010-07-14
Using the correlated signal and idler photon pairs generated in a dispersion shifted fiber by a pulsed pump, we measure the quantum efficiency of a InGaAs/InP avalanche photodiode-based single photon detector. Since the collection efficiency of photon pairs is a key parameter to correctly deduce the quantum efficiency, we carefully characterize the collection efficiency by studying correlation dependence of photon pairs upon the spectra of pump, signal and idler photons. This study allows us to obtain quantum efficiency of the single photon detector by using photon pairs with various kinds of bandwidths.
Exact solution of the p+ip Hamiltonian revisited: duality relations in the hole-pair picture
Jon Links; Ian Marquette; Amir Moghaddam
2015-04-02
We study the exact Bethe Ansatz solution of the p+ip Hamiltonian in a form whereby quantum numbers of states refer to hole-pairs, rather than particle-pairs used in previous studies. We find an asymmetry between these approaches. For the attractive system states in the strong pairing regime take the form of a quasi-condensate involving two distinct hole-pair creation operators. An analogous feature is not observed in the particle-pair picture.
Space qualified nanosatellite electronics platform for photon pair experiments
Cliff Cheng; Rakhitha Chandrasekara; Yue Chuan Tan; Alexander Ling
2015-05-25
We report the design and implementation of a complete electronics platform for conducting a quantum optics experiment that will be operated on board a 1U CubeSat (a 10 x 10 x 10 cm satellite). The quantum optics experiment is designed to produce polarization-entangled photon pairs using non-linear optical crystals and requires opto-electronic components such as a pump laser, single photon detectors and liquid crystal based polarization rotators in addition to passive optical elements. The platform provides mechanical support for the optical assembly. It also communicates autonomously with the host satellite to provide experiment data for transmission to a ground station. A limited number of commands can be transmitted from ground to the platform enabling it to switch experimental modes. This platform requires less than 1.5W for all operations, and is space qualified. The implementation of this electronics platform is a major step on the road to operating quantum communication experiments using nanosatellites.
The Drinfel'd polynomial of a tridiagonal pair
Ito, Tatsuro
2008-01-01
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\{V_i\\}{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\{V^*_i\\}{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
Top Quark Properties from Top Pair Events and Decays
Andrew G. Ivanov; for the CDF; Dzero Collaborations
2008-10-19
Over a decade since the discovery of the top quark we are still trying to unravel mysteries of the heaviest observed particle and learn more about its nature. The continuously accumulating statistics of CDF and Dzero data provide the means for measuring top quark properties with ever greater precision and the opportunity to search for signs of new physics that could be manifested through subtle deviations from the standard model in the production and decays of top quarks. In the following we present a slice of the rich program in top quark physics at the Fermilab Tevatron: measurements of the properties of top quark decays and searches for unusual phenomena in events with pair produced tops. In particular, we discuss the most recent and precise CDF and Dzero measurements of the transverse polarization of W bosons from top decays, branching ratios and searches for flavor-changing neutral current decays, decays into charged Higgs and invisible decays. These analyses correspond to integrated luminosities ranging from 0.9 to 2.7 inv. fb.
Two-dimensional simulations of pulsational pair-instability supernovae
Chen, Ke-Jung; Woosley, Stan [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Melbourne, Victoria 3800 (Australia); Almgren, Ann [Center for Computational Sciences and Engineering, Lawrence Berkeley National Lab, Berkeley, CA 94720 (United States); Whalen, Daniel J., E-mail: kchen@ucolick.org [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2014-09-01
Massive stars that end their lives with helium cores in the range of 35-65 M {sub ?} are known to produce repeated thermonuclear outbursts due to a recurring pair-instability. In some of these events, solar masses of material are ejected in repeated outbursts of several × 10{sup 50} erg each. Collisions between these shells can sometimes produce very luminous transients that are visible from the edge of the observable universe. Previous one-dimensional (1D) studies of these events produce thin, high-density shells as one ejection plows into another. Here, in the first multi-dimensional simulations of these collisions, we show that the development of a Rayleigh-Taylor instability truncates the growth of the high-density spike and drives mixing between the shells. The progenitor is a 110 M {sub ?} solar-metallicity star that was shown in earlier work to produce a superluminous supernova. The light curve of this more realistic model has a peak luminosity and duration that are similar to those of 1D models but a structure that is smoother.
Neutrino-pair bremsstrahlung by electrons in neutron star crusts
A. D. Kaminker; C. J. Pethick; A. Y. Potekhin; V. Thorsson; D. G. Yakovlev
1998-12-25
Neutrino-pair bremsstrahlung by relativistic degenerate electrons in a neutron-star crust at densities (10^9 - 1.5x10^{14}) g/cm^3 is analyzed. The processes taken into account are neutrino emission due to Coulomb scattering of electrons by atomic nuclei in a Coulomb liquid, and electron-phonon scattering and Bragg diffraction (the static-lattice contribution) in a Coulomb crystal. The static-lattice contribution is calculated including the electron band-structure effects for cubic Coulomb crystals of different types and also for the liquid crystal phases composed of rod- and plate-like nuclei in the neutron-star mantle (at 10^{14} - 1.5x10^{14} g/cm^3). The phonon contribution is evaluated with proper treatment of the multi-phonon processes which removes a jump in the neutrino bremsstrahlung emissivity at the melting point obtained in previous works. Below 10^{13} g/cm^3, the results are rather insensitive to the nuclear form factor, but results for the solid state near the melting point are affected significantly by the Debye-Waller factor and multi-phonon processes. At higher densities, the nuclear form factor becomes more significant. A comparison of the various neutrino generation mechanisms in neutron star crusts shows that electron bremsstrahlung is among the most important ones.
RPT_PERIOD","R_S_NAME","LINE_NUM","PROD_CODE","PROD_NAME","PORT_CODE","PORT_CITY
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Pairing properties and specific heat of the inner crust of a neutron star
A. Pastore
2014-12-29
We investigate the pairing properties at finite temperature of the Wigner-Seitz cells in the inner crust of a neutron star obtained with the recent Brussels-Montreal Skyrme functional BSk21. In particular we analyze the phenomena of persistence and reentrance of pairing correlations and their impact on the specific heat in the low-density region of the inner crust.
Pairing properties and specific heat of the inner crust of a neutron star
Pastore, A
2014-01-01
We investigate the pairing properties at finite temperature of the Wigner-Seitz cells in the inner crust of a neutron star obtained with the recent Brussels-Montreal Skyrme functional BSk21. In particular we analyze the phenomena of persistence and reentrance of pairing correlations and their impact on the specific heat in the low-density region of the inner crust.
FOURIER PAIRS OF DISCRETE SUPPORT WITH LITTLE STRUCTURE MIHAIL N. KOLOUNTZAKIS
Kolountzakis, Mihalis
FOURIER PAIRS OF DISCRETE SUPPORT WITH LITTLE STRUCTURE MIHAIL N. KOLOUNTZAKIS Abstract. We give line of discrete support, whose Fourier Transform is also a measure of discrete support, yet this Fourier pair cannot be constructed by repeatedly applying the Poisson Summation Formula finitely many
Induction logging device with a pair of mutually perpendicular bucking coils
Koelle, Alfred R. (Los Alamos, NM); Landt, Jeremy A. (Los Alamos, NM)
1981-01-01
An instrument is disclosed for mapping vertical conductive fractures in a resistive bedrock, magnetically inducing eddy currents by a pair of vertically oriented, mutually perpendicular, coplanar coils. The eddy currents drive magnetic fields which are picked up by a second, similar pair of coils.
Pairing-Based Onion Routing with Improved Forward Secrecy Aniket Kate Greg M. Zaverucha Ian Goldberg
International Association for Cryptologic Research (IACR)
to scale gracefully. Keywords: onion routing, Tor, pairing-based cryptography, anonymous key agreementPairing-Based Onion Routing with Improved Forward Secrecy Aniket Kate Greg M. Zaverucha Ian {akate,gzaveruc,iang}@cs.uwaterloo.ca Abstract This paper presents new protocols for onion routing
AN ASSESSMENT OF WOOD DUCK DISTRIBUTION, ABUNDANCE AND RIPARIAN BREEDING PAIR HABITATS IN SOUTH #12;AN ASSESSMENT OF WOOD DUCK DISTRIBUTION, ABUNDANCE AND RIPARIAN BREEDING PAIR HABITATS IN SOUTH Wildlife and Fisheries Sciences #12;AN ASSESSMENT OF WOOD DUCK DISTRIBUTION, ABUNDANCE AND RIPARIAN
Laughlin, David E.
crystalline alloys P. R. Ohodnicki,a M. E. McHenry, and D. E. Laughlin Materials Science and Engineering ordering in bcc crystalline alloys using the Néel pair model and a Metropolis-type algorithm are reported alloys including poly- crystalline NiFe.6,7 Recently, directional pair ordering in a crystalline phase
Kinetic Energy Driven Pairing in Cuprate Superconductors Th. A. Maier,1
Jarrell, Mark
to the potential energy that electrons can gain by forming Cooper pairs. However, recent optical experiments showKinetic Energy Driven Pairing in Cuprate Superconductors Th. A. Maier,1 M. Jarrell,2 A. Macridin,2 of the electronic potential energy accompanied by an increase in kinetic energy. In the underdoped cuprates, optical
Differential top pair cross section and top anti-top plus jets Physics
Malgorzata Worek
2013-02-14
A brief summary of the current status of the next-to-leading order QCD corrections to top quark pair production and the associated production of top anti-top with jet(s) in different configurations, i.e. with one jet, two jets and another top anti-top pair, is presented.
Affine Pairings on ARM Tolga Acar, Kristin Lauter, Michael Naehrig, and Daniel Shumow
International Association for Cryptologic Research (IACR)
Affine Pairings on ARM Tolga Acar, Kristin Lauter, Michael Naehrig, and Daniel Shumow Microsoft and projective pairings on a dual-core Cortex A9 ARM processor and compare perfor- mance of the same implementation across three platforms: x86, x86-64 and ARM. Using a fast inversion in the base field and doing
Nuclear Physics A 781 (2007) 317341 Symmetry energies, pairing energies, and mass
O'Donnell, Tom
2007-01-01
Nuclear Physics A 781 (2007) 317341 Symmetry energies, pairing energies, and mass equations J and pairing energies of atomic nuclei are related to the differences between the excitation energies of isobaric analog states in the same nucleus. Numerous such excitation energies are known exper- imentally
Efficient Method for Magnitude Comparison in RNS Based on Two Pairs of Conjugate Moduli
Sousa, Leonel
Efficient Method for Magnitude Comparison in RNS Based on Two Pairs of Conjugate Moduli Leonel (RNS) is very useful to achieve carry free arithmetic. How- ever it makes the comparison of numbers method for magnitude comparison in RNS. Moreover, magnitude comparison for RNS that rely on pairs
Methods and compositions for the production of orthogonal tRNA-aminoacyl-tRNA synthetase pairs
Schultz, Peter G. (La Jolla, CA); Wang, Lei (San Diego, CA); Anderson, John Christopher (San Diego, CA); Chin, Jason W. (San Diego, CA); Liu, David R. (Lexington, MA); Magliery, Thomas J. (North Haven, CT); Meggers, Eric L. (Philadelphia, PA); Mehl, Ryan Aaron (San Diego, CA); Pastrnak, Miro (San Diego, CA); Santoro, Stephen William (San Diego, CA); Zhang, Zhiwen (San Diego, CA)
2011-09-06
This invention provides compositions and methods for generating components of protein biosynthetic machinery including orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases. Methods for identifying orthogonal pairs are also provided. These components can be used to incorporate unnatural amino acids into proteins in vivo.
Methods and composition for the production of orthogonal tRNA-aminoacyltRNA synthetase pairs
Schultz, Peter G. (La Jolla, CA); Wang, Lei (San Diego, CA); Anderson, John Christopher (San Diego, CA); Chin, Jason (Cambridge, GB); Liu, David R. (Lexington, MA); Magliery, Thomas J. (North Haven, CT); Meggers, Eric L. (Philadelphia, PA); Mehl, Ryan Aaron (Lancaster, PA); Pastrnak, Miro (San Diego, CA); Santoro, Steven William (Cambridge, MA); Zhang, Zhiwen (San Diego, CA)
2008-04-08
This invention provides compositions and methods for generating components of protein biosynthetic machinery including orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases. Methods for identifying orthogonal pairs are also provided. These components can be used to incorporate unnatural amino acids into proteins in vivo.
Methods and composition for the production of orthogonal tRNA-aminoacyltRNA synthetase pairs
Schultz, Peter G. (La Jolla, CA); Wang, Lei (San Diego, CA); Anderson, John Christopher (San Diego, CA); Chin, Jason (Cambridge, GB); Liu, David R. (Lexington, MA); Magliery, Thomas J. (North Haven, CT); Meggers, Eric L. (Philadelphia, PA); Mehl, Ryan Aaron (Lancaster, PA); Pastrnak, Miro (San Diego, CA); Santoro, Steven William (Cambridge, MA); Zhang, Zhiwen (San Diego, CA)
2012-05-22
This invention provides compositions and methods for generating components of protein biosynthetic machinery including orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases. Methods for identifying orthogonal pairs are also provided. These components can be used to incorporate unnatural amino acids into proteins in vivo.
High-Speed Software Implementation of the Optimal Ate Pairing over BarretoNaehrig
International Association for Cryptologic Research (IACR)
High-Speed Software Implementation of the Optimal Ate Pairing over BarretoÂNaehrig Curves Jean-0052 Abstract. This paper describes the design of a fast software library for the computation of the optimal ate, finite field arithmetic, bilinear pairing software implementation. 1 Introduction The protocol solutions
MULTI-DIMENSIONAL SIMULATIONS OF ROTATING PAIR-INSTABILITY SUPERNOVAE
Chatzopoulos, E.; Wheeler, J. Craig [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Couch, Sean M., E-mail: manolis@astro.as.utexas.edu [Department of Astronomy and Astrophysics, Flash Center for Computational Science, University of Chicago, Chicago, IL 60637 (United States)
2013-10-20
We study the effects of rotation on the dynamics, energetics, and {sup 56}Ni production of pair instability supernova (PISN) explosions by performing rotating two-dimensional ({sup 2}.5D{sup )} hydrodynamics simulations. We calculate the evolution of eight low-metallicity (Z = 10{sup –3}, 10{sup –4} Z{sub ?}) massive (135-245 M{sub ?}) PISN progenitors with initial surface rotational velocities of 50% of the critical Keplerian value using the stellar evolution code MESA. We allow for both the inclusion and the omission of the effects of magnetic fields in the angular momentum transport and in chemical mixing, resulting in slowly rotating and rapidly rotating final carbon-oxygen cores, respectively. Increased rotation for carbon-oxygen cores of the same mass and chemical stratification leads to less energetic PISN explosions that produce smaller amounts of {sup 56}Ni due to the effect of the angular momentum barrier that develops and slows the dynamical collapse. We find a non-monotonic dependence of {sup 56}Ni production on rotational velocity in situations when smoother composition gradients form at the outer edge of the rotating cores. In these cases, the PISN energetics are determined by the competition of two factors: the extent of chemical mixing in the outer layers of the core due to the effects of rotation in the progenitor evolution and the development of angular momentum support against collapse. Our 2.5D PISN simulations with rotation are the first presented in the literature. They reveal hydrodynamic instabilities in several regions of the exploding star and increased explosion asymmetries with higher core rotational velocity.
Jun Li; Gianluca Colo'; Jie Meng
2008-11-25
A self-consistent Quasiparticle-Random-Phase-Approximation (QRPA) model which employs the canonical Hartree-Fock-Bogoliubov (HFB) basis and an energy-density functional with a Skyrme mean field part and a density-dependent pairing, is used to study the monopole collective excitations of spherical even-even nuclei. The influence of the spurious state on the strength function of the isoscalar monopole excitations is clearly assessed. We compare the effect of different kinds of pairing forces (volume pairing, surface pairing and mixed pairing) on the monopole excitation strength function. The energy of the Isoscalar Giant Monopole Resonance (ISGMR), which is related to the nuclear incompressibility $K_{\\infty}$, is calculated for tin isotopes and the results are discussed.
A weak-value interpretation of the Schwinger mechanism of massless/massive pair productions
Kazuhiro Yokota; Nobuyuki Imoto
2015-04-28
According to the Schwinger mechanism, a uniform electric field brings about pair productions in vacuum; the relationship between the production rate and the electric field is different, depending on the dimension of the system. In this paper, we make an offer of another model for the pair productions, in which weak values are incorporated: energy fluctuations trigger the pair production, and a weak value appears as the velocity of a particle there. Although our model is only available for the approximation of the pair production rates, the weak value reveals a new aspect of the pair production. Especially, within the first order, our estimation approximately agrees with the exponential decreasing rate of the Landau-Zener tunneling through the mass energy gap. In other words, such tunneling can be associated with energy fluctuations via the weak value, when the tunneling gap can be regarded as so small due to the high electric field.
Competition between magnetic and superconducting pairing exchange interactions in confined systems
Ying Zujian; Cuoco, Mario; Noce, Canio; Zhou Huanqiang
2007-10-01
We analyze the competition between magnetic and pairing interactions in confined systems relevant to either small superconducting grains or trapped ultracold atomic gases. The response to the imbalance of the chemical potential for the two spin states leads to various inhomogeneous profiles of the pair energy distribution. We show that the position in the energy spectrum for the unpaired particles can be tuned by varying the filling or the pairing strength. When small grains are considered, the antiferromagnetic exchange stabilizes the pair correlations, whereas for Fermi gases, a transition from a mixed configuration to a phase-separated one beyond a critical polarization threshold appears, as does an unconventional phase with a paired shell around a normal core.
Coherent chemical kinetics as quantum walks I: Reaction operators for radical pairs
A. Chia; A. Gorecka; K. C. Tan; L. Pawela; P. Kurzynski; T. Paterek; D. Kaszlikowski
2015-06-13
Classical chemical kinetics use rate-equation models to describe how a reaction proceeds in time. Such models are sufficient for describing state transitions in a reaction where coherences between different states do not arise, or in other words, a reaction which contain only incoherent transitions. A prominent example reaction containing coherent transitions is the radical-pair model. The kinetics of such reactions is defined by the so-called reaction operator which determines the radical-pair state as a function of intermediate transition rates. We argue that the well-known concept of quantum walks from quantum information theory is a natural and apt framework for describing multisite chemical reactions. By composing Kraus maps that act only on two sites at a time, we show how the quantum-walk formalism can be applied to derive a reaction operator for the standard avian radical-pair reaction. Our reaction operator predicts a recombination dephasing rate consistent with recent experiments [J. Chem. Phys. {\\bf 139}, 234309 (2013)], in contrast to previous work by Jones and Hore [Chem. Phys. Lett. {\\bf 488}, 90 (2010)]. The standard radical-pair reaction has conventionally been described by either a normalised density operator incorporating both the radical pair and reaction products, or by a trace-decreasing density operator that considers only the radical pair. We demonstrate a density operator that is both normalised and refers only to radical-pair states. Generalisations to include additional dephasing processes and an arbitrary number of sites are also discussed.
Optical flashes from internal pairs formed in gamma-ray burst afterglows
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Panaitescu, A.
2015-06-09
We develop a numerical formalism for calculating the distribution with energy of the (internal) pairs formed in a relativistic source from unscattered MeV–TeV photons. For gamma-ray burst (GRB) afterglows, this formalism is more suitable if the relativistic reverse shock that energizes the ejecta is the source of the GeV photons. The number of pairs formed is set by the source GeV output (calculated from the Fermi-LAT fluence), the unknown source Lorentz factor, and the unmeasured peak energy of the LAT spectral component. We show synchrotron and inverse-Compton light curves expected from pairs formed in the shocked medium and identify somemore »criteria for testing a pair origin of GRB optical counterparts. Pairs formed in bright LAT afterglows with a Lorentz factor in the few hundreds may produce bright optical counterparts ($R\\lt 10$) lasting for up to one hundred seconds. As a result, the number of internal pairs formed from unscattered seed photons decreases very strongly with the source Lorentz factor, thus bright GRB optical counterparts cannot arise from internal pairs if the afterglow Lorentz factor is above several hundreds.« less
Coherent chemical kinetics as quantum walks I: Reaction operators for radical pairs
A. Chia; A. Gorecka; K. C. Tan; L. Pawela; P. Kurzynski; T. Paterek; D. Kaszlikowski
2015-08-20
Classical chemical kinetics use rate-equation models to describe how a reaction proceeds in time. Such models are sufficient for describing state transitions in a reaction where coherences between different states do not arise, or in other words, a reaction which contain only incoherent transitions. A prominent example reaction containing coherent transitions is the radical-pair model. The kinetics of such reactions is defined by the so-called reaction operator which determines the radical-pair state as a function of intermediate transition rates. We argue that the well-known concept of quantum walks from quantum information theory is a natural and apt framework for describing multisite chemical reactions. By composing Kraus maps that act only on two sites at a time, we show how the quantum-walk formalism can be applied to derive a reaction operator for the standard avian radical-pair reaction. Our reaction operator predicts a recombination dephasing rate consistent with recent experiments [J. Chem. Phys. {\\bf 139}, 234309 (2013)], in contrast to previous work by Jones and Hore [Chem. Phys. Lett. {\\bf 488}, 90 (2010)]. The standard radical-pair reaction has conventionally been described by either a normalised density operator incorporating both the radical pair and reaction products, or by a trace-decreasing density operator that considers only the radical pair. We demonstrate a density operator that is both normalised and refers only to radical-pair states. Generalisations to include additional dephasing processes and an arbitrary number of sites are also discussed.
Theory of nodal s±-wave pairing symmetry in the Pu-based 115 superconductor family
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Das, Tanmoy; Zhu, Jian -Xin; Graf, Matthias J.
2015-02-27
The spin-fluctuation mechanism of superconductivity usually results in the presence of gapless or nodal quasiparticle states in the excitation spectrum. Nodal quasiparticle states are well established in copper-oxide, and heavy-fermion superconductors, but not in iron-based superconductors. Here, we study the pairing symmetry and mechanism of a new class of plutonium-based high-Tc superconductors and predict the presence of a nodal s?? wave pairing symmetry in this family. Starting from a density-functional theory (DFT) based electronic structure calculation we predict several three-dimensional (3D) Fermi surfaces in this 115 superconductor family. We identify the dominant Fermi surface “hot-spots” in the inter-band scattering channel,more »which are aligned along the wavevector Q = (?, ?, ?), where degeneracy could induce sign-reversal of the pairing symmetry. Our calculation demonstrates that the s?? wave pairing strength is stronger than the previously thought d-wave pairing; and more importantly, this pairing state allows for the existence of nodal quasiparticles. Finally, we predict the shape of the momentum- and energy-dependent magnetic resonance spectrum for the identification of this pairing symmetry.« less
Distribution of Primes and of Interval Prime Pairs Based on $?$ Function
Yifang Fan; Zhiyu Li
2010-04-19
$\\Theta$ function is defined based upon Kronecher symbol. In light of the principle of inclusion-exclusion, $\\Theta$ function of sine function is used to denote the distribution of composites and primes. The structure of Goldbach Conjecture has been analyzed, and $\\Xi$ function is brought forward by the linear diophantine equation; by relating to $\\Theta$ function, the interval distribution of composite pairs and prime pairs (i.e. the Goldbach Conjecture) is thus obtained. In the end, Abel's Theorem (Multiplication of Series) is used to discuss the lower limit of the distribution of the interval prime pairs.
Cal Latin-Small-Letter-Dotless-I k, A. E.; Gerceklioglu, M.; Selam, C.
2013-05-15
Within the framework of quasi-particle random phase approximation, the isospin breaking correction of superallowed 0{sup +} {yields} 0{sup +} beta decay and unitarity of Cabibbo-Kobayashi-Maskawa mixing matrix have been investigated. The broken isotopic symmetry of nuclear part of Hamiltonian has been restored by Pyatov's method. The isospin symmetry breaking correction with pairing correlations has been compared with the previous results without pairing. The effect of pairing interactions has been examined for nine superallowed Fermi beta decays; their parent nuclei are {sup 26}Al, {sup 34}Cl, {sup 38}K, {sup 42}Sc, {sup 46}V, {sup 50}Mn, {sup 54}Co, {sup 62}Ga, {sup 74}Rb.
Irradiation test on FD-SOI Readout ASIC of Pair-monitor
Yutaro Sato; Hirokazu Ikeda; Akiya Miyamoto; Yosuke Takubo; Toshiaki Tauchi; Hitoshi Yamamoto
2010-06-22
We fabricated a readout ASIC with the fully depleted silicon-on-insulator (FD-SOI) technology for the pair-monitor. The pair-monitor is a silicon pixel device that measures the beam profile of the international linear collider. It utilizes the directional distribution of a large number of electron-positron pairs created by collision of bunches, and is required to tolerate radiation dose of about a few Mrad/year. The irradiation might cause the buried oxide layer of SOI to accumulate charges which interfere with intended functions. We thus performed extensive irradiation tests on the prototype ASIC, and the results are described in this paper.
Choi, Mahn-Soo
2014-01-01
PHYSICAL REVIEW B 89, 045137 (2014) Hanbury Brown and Twiss correlations of Cooper pairs in helical; published 29 January 2014) We propose a Hanbury Brown and Twiss (HBT) experiment of Cooper pairs on the edge a Hanbury Brown and Twiss (HBT) experiment of Cooper pairs on the edge channels of quantum spin Hall
Shepelyansky, Dima
Disordered Hubbard model with attraction: The coupling energy of Cooper pairs in small clusters of disorder. We show that the Cooper pair energy is strongly enhanced by disorder, which at the same time us to determine the depen- dence of the Cooper pair coupling energy on the strength of disorder
Xiong, Hui
TOP-COP: Mining TOP-K Strongly Correlated Pairs in Large Databases Hui Xiong MSIS Department. To this end, we propose an alterna- tive task: mining the top-k strongly correlated pairs. In this paper, we an efficient algorithm, called TOP-COP to exploit this prop- erty to effectively prune many pairs even without
Mao, James X.; Lee, Anita S.; Kitchin, John R.; Nulwala, Hunaid B; Luebke, David R.; Damodaran, Krishnan
2013-04-24
Density Functional Theory is used to investigate a weakly coordinating room-temperature ionic liquid, 1-ethyl-3-methyl imidazolium tetracyanoborate ([Emim]{sup +}[TCB]{sup -}). Four locally stable conformers of the ion pair were located. Atoms-in-molecules (AIM) and electron density analysis indicated the existence of several hydrogen bonds. Further investigation through the Natural Bond Orbital (NBO) and Natural Energy Decomposition Analysis (NEDA) calculations provided insight into the origin of interactions in the [Emim]{sup +}[TCB]{sup -} ion pair. Strength of molecular interactions in the ionic liquid was correlated with frequency shifts of the characteristic vibrations of the ion pair. Harmonic vibrations of the ion pair were also compared with the experimental Raman and Infrared spectra. Vibrational frequencies were assigned by visualizing displacements of atoms around their equilibrium positions and through Potential Energy Distribution (PED) analysis.
Characterization process of emission sources of spin entangled pairs with several species
Francisco Delgado
2011-03-24
Normally, sources of entangled pairs generate several species of them. This work proposes a characterization algorithm for relatively general bipartite entangled states, generating several standard Bell states with controlled population as output.
Pairing of valence electrons as necessary condition for energy minimization in a crystal
Dolgopolov Stanislav Olegovich
2014-10-21
Pairing of valence electrons can lead to energy minimization of a crystal. It can be proved by use of representation of the valence electrons as plane waves in periodic potential of the crystal.
Glutamate-receptor-mediated encoding and retrieval of paired-associate learning
Day, M; Langston, R; Morris, Richard G M
2003-07-10
Paired-associate learning is often used to examine episodic memory in humans (1). Animal models include the recall of foodcache locations by scrub jays (2) and sequential memory (3,4). Here we report a model in which ...
Heralding efficiency and correlated-mode coupling of near-IR fiber-coupled photon pairs
Rosenberg, Danna
We report on a systematic experimental study of the heralding efficiency and generation rate of telecom-band infrared photon pairs generated by spontaneous parametric down-conversion and coupled to single-mode optical ...
Search for new ?[superscript 0]-like particles produced in association with a ?-lepton pair
Lees, J.?P.
We report on a search in e[superscript +]e[superscript -] annihilations for new ?[superscript 0]-like particles produced in association with a ?-lepton pair. These objects, with a similar mass and similar decay modes to ...
Ooi, C. H. Raymond; Scully, Marlan O.; Sun, Qingqing; Zubairy, M. Suhail
2007-01-01
We present a largely analytical theory for two-photon correlations G((2)) between Stokes (s) and anti-Stokes (a) photon pairs from an extended medium (amplifier) composed of double-Lambda atoms in counterpropagating geometry. We generalize...
Correlating structure and thermodynamics of hydrophobicâ??hydrophilic ion pairs in water
Benjamin, Ilan
2015-01-01
TMA-halide ion pairs in water at 298K. r is the distanceshows the nitrogen(TMA)-oxygen(water) radial distributionfunction in pure water. The main plot shows the peak value (
Nonequilibrium superconducting thin films with sub-gap and pair-breaking photon illumination
Guruswamy, T.; Goldie, D. J.; Withington, S.
2015-04-08
We calculate nonequilibrium quasiparticle and phonon distributions for a number of widely-used low transition temperature thin-film superconductors under constant, uniform illumination by sub-gap probe and pair-breaking signal photons simultaneously...
Pair correlations in neutrinoless double {beta} decay candidate {sup 130}Te.
Bloxham, T.; Kay, B. P.; Schiffer, J. P.; Clark, J. A.; Deibel, C. M.; Freeman, S. J.; Freedman, S. J.; Howard, A. M.; McAllister, S. A.; Parker, P. D.; Sharp, D. K.; Thomas, J. S. (Physics); ( PSC-USR); (LBNL); (Michigan State Univ.); (Univ. of Manchester); (Yale Univ.)
2010-08-16
Pair correlations in the ground state of {sup 130}Te have been investigated using pair-transfer experiments to explore the validity of approximations in calculating the matrix element for neutrinoless double-{beta} decay. This nucleus is a candidate for the observation of such decay, and a good understanding of its structure is crucial for eventual calculations of the neutrino mass, should such a decay indeed be observed. For proton-pair adding, strong transitions to excited 0{sup +} states had been observed in the Te isotopes by Alford et al. [Nucl. Phys. A 323, 339 (1979)], indicating a breaking of the BCS approximation for protons in the ground state. We measured the neutron-pair removing (p,t) reaction on {sup 130}Te and found no indication of a corresponding splitting of the BCS nature of the ground state for neutrons.
Pair correlations in the neutrinoless double-{beta} decay candidate {sup 130}Te
Bloxham, T.; Freedman, S. J. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Kay, B. P.; Schiffer, J. P.; Clark, J. A. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Deibel, C. M. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48825 (United States); Freeman, S. J.; Howard, A. M.; McAllister, S. A.; Sharp, D. K.; Thomas, J. S. [Schuster Laboratory, University of Manchester, Manchester, M13 9PL (United Kingdom); Parker, P. D. [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States)
2010-08-15
Pair correlations in the ground state of {sup 130}Te have been investigated using pair-transfer experiments to explore the validity of approximations in calculating the matrix element for neutrinoless double-{beta} decay. This nucleus is a candidate for the observation of such decay, and a good understanding of its structure is crucial for eventual calculations of the neutrino mass, should such a decay indeed be observed. For proton-pair adding, strong transitions to excited 0{sup +} states had been observed in the Te isotopes by Alford et al. [Nucl. Phys. A 323, 339 (1979)], indicating a breaking of the BCS approximation for protons in the ground state. We measured the neutron-pair removing (p,t) reaction on {sup 130}Te and found no indication of a corresponding splitting of the BCS nature of the ground state for neutrons.
Photon pair generation from compact silicon microring resonators using microwatt-level pump powers
Savanier, Marc; Mookherjea, Shayan
2015-01-01
Microring resonators made from silicon, using deep ultraviolet lithography fabrication processes which are scalable and cost-effective, are becoming a popular microscale device format for generating photon pairs at telecommunications wavelengths at room temperature. In compact devices with a footprint less than $5\\times 10^{-4}$ mm$^2$, we demonstrate pair generation using only a few microwatts of average pump power. We discuss the role played by important parameters such as the loss, group-velocity dispersion and the ring-waveguide coupling coefficient in finding the optimum operating point for silicon microring pair generation. Such small devices and low pump power requirements could be beneficial for future scaled-up architectures with many pair-generation devices on the same chip, which will be required to create quasi-deterministic pure single photon sources from inherently statistical processes such as spontaneous four-wave mixing.
Pairing preferences of the model mono-valence mono-atomic ions investigated by molecular simulation
Zhang, Qiang [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning (China) [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning (China); Department of Chemistry, Bohai University, Jinzhou 121000 (China); Zhang, Ruiting; Zhao, Ying; Li, HuanHuan; Zhuang, Wei, E-mail: wzhuang@dicp.ac.cn, E-mail: gaoyq@pku.edu.cn [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning (China)] [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning (China); Gao, Yi Qin, E-mail: wzhuang@dicp.ac.cn, E-mail: gaoyq@pku.edu.cn [College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871 (China)
2014-05-14
We carried out a series of potential of mean force calculations to study the pairing preferences of a series of model mono-atomic 1:1 ions with evenly varied sizes. The probabilities of forming the contact ion pair (CIP) and the single water separate ion pair (SIP) were presented in the two-dimensional plots with respect to the ion sizes. The pairing preferences reflected in these plots largely agree with the empirical rule of matching ion sizes in the small and big size regions. In the region that the ion sizes are close to the size of the water molecule; however, a significant deviation from this conventional rule is observed. Our further analysis indicated that this deviation originates from the competition between CIP and the water bridging SIP state. The competition is mainly an enthalpy modulated phenomenon in which the existing of the water bridging plays a significant role.
Conversion of relativistic pair energy into radiation in the jets of active galactic nuclei
Schlickeiser, R; Böttcher, M; Lerche, I; Pohl, M; Schuster, C
2002-01-01
It is generally accepted that relativistic jet outflows power the nonthermal emission from active galactic nuclei (AGN). The composition of these jets -- leptonic versus hadronic -- is still under debate. We investigate the microphysical details of the conversion process of the kinetic energy in collimated relativistic pair outflows into radiation through interactions with the ambient interstellar medium. Viewed from the coordinate system comoving with the pair outflow, the interstellar protons and electrons represent a proton-electron beam propagating with relativistic speed in the pair plasma. We demonstrate that the beam excites both electrostatic and low-frequency magnetohydrodynamic Alfven-type waves via a two-stream instability in the pair background plasma, and we calculate the time evolution of the distribution functions of the beam particles and the generated plasma wave turbulence power spectra. For standard AGN jet outflow and environment parameters we show that the initial beam distributions of in...
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Mani, Tomoyasu; Grills, David C.; Miller, John R.
2015-01-02
A recently-developed instrument for time-resolved infrared detection following pulse radiolysis has been used to measure the ?(C?N) IR band of the radical anion of a CN-substituted fluorene in tetrahydrofuran. Specific vibrational frequencies can exhibit distinct frequency shifts due to ion-pairing, which can be explained in the framework of the vibrational Stark effect. Measurements of the ratio of free ions and ion-pairs in different electrolyte concentrations allowed us to obtain an association constant and free energy change for ion-pairing. As a result, this new method has the potential to probe the geometry of ion-pairing and allows the reduction potentials of moleculesmore »to be determined in the absence of electrolyte in an environment of low dielectric constant.« less
Top Quark Pair Production Measurements Using the ATLAS Detector at the LHC
Bertsche, Carolyn; The ATLAS collaboration
2015-01-01
Measurements of the inclusive top quark pair production cross sections in protonproton collisions with the ATLAS detector at the Large Hadron Collider are presented. The most precise result requires opposite sign electrons and muons and uses the full dataset at a centreofmass energy of 7 and 8 TeV. In addition, differential measurements of the top transverse momentum and kinematic properties of the topantitop pair are discussed. These measurements, including results using boosted tops, probe our understanding of top pair production in the TeV regime. The results, unfolded to particle and parton level, are compared to recent Monte Carlo generators implementing LO and NLO matrix elements matched with parton showers and NLO QCD calculations. In addition, measurements of the production of top quark pairs in association with gauge bosons or jets are presented.
Gomez-Ceballos, Guillelmo
We combine six measurements of the inclusive top-quark pair (t[bar over t]) production cross section (?[subscript tt]-) from data collected with the CDF and D0 detectors at the Fermilab Tevatron with proton-antiproton ...
Pairing within the self-consistent quasiparticle random-phase approximation at finite temperature
Dang, N Dinh
2008-01-01
An approach to pairing in finite nuclei at nonzero temperature is proposed, which incorporates the effects due to the quasiparticle-number fluctuation (QNF) around Bardeen-Cooper-Schrieffer (BCS) mean field and dynamic coupling to quasiparticle-pair vibrations within the self-consistent quasiparticle random-phase approximation (SCQRPA). The numerical calculations of pairing gap, total energy, and heat capacity were carried out within a doubly folded multilevel model as well as realistic nuclei $^{56}$Fe and $^{120}$Sn. The results obtained show that, under the effect of QNF, in the region of moderate and strong couplings, the sharp transition between the superconducting and normal phases is smoothed out, resulting in a thermal pairing gap, which does not collapse at the BCS critical temperature, but has a tail, which extends to high temperature. The dynamic coupling of quasiparticles to SCQRPA vibrations significantly improves the agreement with the results of exact calculations and those obtained within the ...
Electroweak production of top-quark pairs in e + e - annihilation...
Office of Scientific and Technical Information (OSTI)
Electroweak production of top-quark pairs in e + e - annihilation at NNLO in QCD: The vector current contributions Citation Details In-Document Search This content will become...
Parallel Assembly of Large Genomes from Paired Short Reads (2010 JGI/ANL HPC Workshop)
Aluru, Srinivas [Iowa State University
2011-06-08
Srinivas Aluru from Iowa State University gives a presentation on "Parallel Assembly of Large Genomes from Paired Short Reads" at the JGI/Argonne HPC Workshop on January 25, 2010.
A. J. Baltz
1997-01-10
An exact solution of the time-dependent Dirac equation for ionization and pair production induced by ultrarelativistic heavy ion collisions is presented. Exact transition probabilities, equivalent to those that would be obtained in an untruncated basis coupled channels calculation, are presented. Exact bound-electron positron pair production probabilities are calculated to be mostly smaller than those calculated with the same potential in perturbation theory at impact parameters small enough for differences to occur.
A. G. Aksenov; M. Milgrom; V. V. Usov
2004-03-15
We consider a stationary, spherically outflowing wind consisting of electron-positron pairs and photons. We do not assume thermal equilibrium, and include the two-body processes that occur in such a wind: Moller and Bhaba scattering of pairs, Compton scattering, two-photon pair annihilation, and two-photon pair production, together with their radiative three-body variants: bremsstrahlung, double Compton scattering, and three-photon pair annihilation, with their inverse processes. In the concrete example described here, the wind injection source is a hot, bare, strange star. Such stars are thought to be powerful sources of pairs created by the Coulomb barrier at the quark surface. We present a new, finite-difference scheme for solving the relativistic kinetic Boltzmann equations for pairs and photons. Using this method we study the kinetics of the wind particles and the emerging emission for total luminosities of L=10^{34}-10^{42} ergs/s. We find the rates of particle number and energy outflows, outflow velocities, number densities, energy spectra, and other parameters for both photons and pairs as functions of the distance. We find that for L>2x10^{35} ergs/s, photons dominate the emerging emission. As L increases from ~ 10^{34} to 10^{42} ergs/s, the mean energy of emergent photons decreases from ~400-500 keV to 40 keV, as the spectrum changes in shape from that of a wide annihilation line to nearly a blackbody spectrum with a high energy (> 100 keV) tail. These results are pertinent to the deduction of the outside appearance of hot bare strange stars, which might help discern them from neutron stars.
Reaction operators for spin-selective chemical reactions of radical pairs
Jonathan A. Jones; Kiminori Maeda; Peter J. Hore
2011-03-30
Spin-selective reactions of radical pairs have traditionally been modelled theoretically by adding phenomenological rate equations to the quantum mechanical equation of motion of the radical pair spin density matrix. More recently an alternative set of rate expressions, based on a quantum measurement approach, has been suggested. Here we show how these two reaction operators can be seen as limiting cases of a more general reaction scheme.
Relativistic mean field plus exact pairing approach to open shell nuclei
Wei-Chia Chen; J. Piekarewicz; A. Volya
2013-11-20
Background: Pairing correlations play a critical role in determining numerous properties of open-shell nuclei. Traditionally, they are included in a mean-field description of atomic nuclei through the approximate Bardeen-Cooper-Schrieffer or Hartree-Fock-Bogoliubov formalism. Purpose: We propose a new hybrid ''relativistic-mean-field-plus-pairing'' approach in which pairing is treated exactly so the number of particles is conserved. To verify the reliability of the formalism, we apply it to the study of both ground-state properties and isoscalar monopole excitations of the Tin isotopes. Methods: Accurately-calibrated relativistic mean-field models supplemented by an exact treatment of pairing correlations are used to compute ground-state observables along the isotopic chain in Tin. In turn, ground-state densities are used as input to the calculation of giant monopole resonances through a constrained-relativistic approach. Results: We compute a variety of ground-state observables sensitive to pairing correlations as well as the evolution of giant monopole energies along the isotopic chain in Tin. Whereas ground-state properties are consistent with experiment, we find that pairing correlations have a minor effect on the giant monopole energies. Conclusions: A new mean-field-plus-pairing approach is introduced to compute properties of open-shell nuclei. The formalism provides an efficient and powerful alternative to the computation of both ground-state properties and monopole energies of open-shell nuclei. We find ground-state properties to be well reproduced in this approach. However, as many have concluded before us, we find that pairing correlations are unlikely to provide an answer to the question of ''why is Tin so soft?''
On Evolution of the Pair-Electromagnetic Pulse of a Charge Black Hole
Remo Ruffini; Jay D. Salmonson; James R. Wilson; She-Sheng Xue
1999-05-04
Using hydrodynamic computer codes, we study the possible patterns of relativistic expansion of an enormous pair-electromagnetic-pulse (P.E.M. pulse); a hot, high density plasma composed of photons, electron-positron pairs and baryons deposited near a charged black hole (EMBH). On the bases of baryon-loading and energy conservation, we study the bulk Lorentz factor of expansion of the P.E.M. pulse by both numerical and analytical methods.
Schwinger Pair Production in dS_2 and AdS_2
Sang Pyo Kim; Don N. Page
2009-02-20
We study Schwinger pair production in scalar QED from a uniform electric field in dS_2 with scalar curvature R_{dS} = 2 H^2 and in AdS_2 with R_{AdS} = - 2 K^2. With suitable boundary conditions, we find that the pair-production rate is the same analytic function of the scalar curvature in both cases.
Bentley, I; Frauendorf, S
2013-01-01
A model with nucleons in a charge independent potential well interacting by an isovector pairing force is considered. For a 24-dimensional valence space, the Hartree-Bogolyubov (HB) plus Random Phase (RPA) approximation to the lowest eigenvalue of the Hamiltonian is shown to be accurate except near values of the pairing force coupling constant G where the HB solution shifts from a zero to a non-zero pair gap. In the limit G->infinity the HB + RPA is asymptotically exact. The inaccuracy of the HB + RPA in the critical regions of G can be remedied by interpolation. The resulting algoritm is used to calculate pairing corrections in the framework of a Nilsson-Strutinsky calculation of nuclear masses near N = Z for A = 24-100, where N and Z are the numbers of neutrons and protons, and A = N + Z. The dimension of the valence space is 2A in these calculations. Adjusting five liquid drop parameters and a power law expression for the constant G as a function of A allows us to reproduce the measured binding energies of...
Optical Flashes from Internal Pairs Formed in Gamma-Ray Burst Afterglows
Panaitescu, A
2015-01-01
We develop a numerical formalism for calculating the distribution with energy of the (internal) pairs formed in a relativistic source from unscattered MeV--TeV photons. For GRB afterglows, this formalism is more suitable if the relativistic reverse-shock that energizes the ejecta is the source of the GeV photons. The number of pairs formed is set by the source GeV output (calculated from the Fermi-LAT fluence), the unknown source Lorentz factor, and the unmeasured peak energy of the LAT spectral component. We show synchrotron and inverse-Compton light-curves expected from pairs formed in the shocked medium and identify some criteria for testing a pair origin of GRB optical counterparts. Pairs formed in bright LAT afterglows with a Lorentz factor in the few hundreds may produce bright optical counterparts (R < 10) lasting for up to one hundred seconds. The number of internal pairs formed from unscattered seed photons decreases very strongly with the source Lorentz factor, thus bright GRB optical counterpart...
Possible Effects of Pair Echoes on Gamma-Ray Burst Afterglow Emission
Kohta Murase; Bing Zhang; Keitaro Takahashi; Shigehiro Nagataki
2009-02-27
High-energy emission from gamma-ray bursts (GRBs) is widely expected but had been sparsely observed until recently when the Fermi satellite was launched. If >TeV gamma rays are produced in GRBs and can escape from the emission region, they are attenuated by the cosmic infrared background photons, leading to regeneration of GeV-TeV secondary photons via inverse-Compton scattering. This secondary emission can last for a longer time than the duration of GRBs, and it is called a pair echo. We investigate how this pair echo emission affects spectra and light curves of high energy afterglows, considering not only prompt emission but also afterglow as the primary emission. Detection of pair echoes is possible as long as the intergalactic magnetic field (IGMF) in voids is weak. We find (1) that the pair echo from the primary afterglow emission can affect the observed high-energy emission in the afterglow phase after the jet break, and (2) that the pair echo from the primary prompt emission can also be relevant, but only when significant energy is emitted in the TeV range, typically E_{gamma, >0.1 TeV} > (Y/(1+Y)) epsilon_e E_k. Even non-detections of the pair echoes could place interesting constraints on the strength of IGMF. The more favorable targets to detect pair echoes may be the "naked" GRBs without conventional afterglow emission, although energetic naked GRBs would be rare. If the IGMF is weak enough, it is predicted that the GeV emission extends to >30-300 s.
P. A. Marchetti; F. Ye; Z. B. Su; L. Yu
2011-05-25
Within a gauge approach to the t-J model, we propose a new, non-BCS mechanism of superconductivity for underdoped cuprates. We implement the no-double occupancy constraint with a (semionic) slave-particle formalism. The dopant generates a vortex-like quantum distortion of the AF background centered on the empty sites, with opposite chirality for cores on the two N\\'eel sublattices. Empty sites are described in terms of spinless fermionic holons and the long-range attraction between spin vortices on two opposite N\\'eel sublattices is the holon pairing force, leading eventually to SC. The spin fluctuations are described by bosonic spinons with a gap generated by scattering on spin vortices. Due to the occupation constraint, there is a gauge attraction between holon and spinon, binding them into a physical hole. Through gauge interaction the spin vortex attraction induces the formation of spin-singlet RVB pairs reducing the spinon gap. Lowering T, there are two crossovers as precursors of the SC transition: at the higher one a gas of holon pairs appears, reducing the hole spectral weight, while at the lower one a gas of spinon pairs also appears, giving rise to a gas of incoherent preformed hole pairs with magnetic vortices in the plasma phase, supporting a Nernst signal. At an even lower T the hole pairs become coherent and SC appears beyond a critical doping. The proposed SC mechanism is not of the BCS-type, because it involves a gain in kinetic energy (lowering of spinon gap) and it is "almost" of the classical 3D XY-type. Since both the spinon gap and the holon pairing originate from the same term in the slave-particle representation of the t-J model, this approach incorporates a strong interplay between AF and SC, giving rise to a universal relation between Tc and the energy of the resonance mode, as observed in neutron scattering experiments.
PROD. TYPE: COM PP:1-11 (col.fig.: nil) CES7571 MODE+
Ferguson, Thomas S.
tank. This process of mixing fluids is analogous to a ce- 45 ment mixer so it only requires one moving Viscous fluid mixing in a tilted tank by periodic shear Thomas Warda, , Asher Metchikb 3 a in revised form 4 July 2007; accepted 17 July 2007 Abstract 7 A tilted-partially filled rotating tank
pp: 1-13 (col.fig.: nil) PROD. TYPE: COM ED: Ramesh
Völker, Norbert
-instrumented functions, such as burner management, emergency shut-11 down and gas leak detection, but also complex
PROD. TYPE: FLP PP:1-11 (col.fig.: nil)
Gutierrez, Jaime
of this topic. Corresponding author. E-mail address: jaime.gutierrez@unican.es (J. Gutierrez). 1 Partially.08.004 #12;U N C O R R EC TED PR O O F 2 J. Gutierrez, D. Sevilla/Finite Fields and Their Applications. #12;U N C O R R EC TED PR O O F YFFTA534 ARTICLE IN PRESS J. Gutierrez, D. Sevilla/Finite Fields
PROD. TYPE: COM PP:1-17 (col.fig.: nil) CBM856 MODE+
Serpen, Gursel
diagnosis (PIOPED) criteria, which represent the pre- eminent collective experiential knowledge base among nuclear radiologists as a diagnosis procedure for PE, are conveniently defined in terms of13 a set of if-based artificial neural network (KBANN) classifier through the modified PIOPED15 criteria for the diagnosis of PE
http://cemp.dri.edu/cgi-bin/cemp_stations.pl?stn=tono&prod=11
National Nuclear Security Administration (NNSA)
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 GasAdministration Medal01 Sandia4)9 Federal RegisterStorm1 34460/%2A en3 Community
http://cemp.dri.edu/cgi-bin/cemp_stations.pl?stn=tono&prod=11
National Nuclear Security Administration (NNSA)
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 GasAdministration Medal01 Sandia4)9 Federal RegisterStorm1 34460/%2A en3 Community1
Comparison of Three Cre-LoxP Based Paired-End Library Construction Methods
Peng, Ze; Nath, Nandita; Tritt, Andrew; Liang, Shoudan; Han, James; Pennacchio, Len; Chen, Feng
2013-03-26
Paired-end library sequencing has been proven useful in scaffold construction during de novo whole genome shotgun assembly. The ability of generating mate pairs with > 8 Kb insert sizes is especially important for genomes containing long repeats. To make mate paired libraries for next generation sequencing, DNA fragments need to be circularized to bring the ends together. There are several methods that can be used for DNA circulation, namely ligation, hybridization and Cre-LoxP recombination. With higher circularization efficiency with large insert DNA fragments, Cre-LoxP recombination method generally has been used for constructing >8 kb insert size paired-end libraries. Second fragmentation step is also crucial for maintaining high library complexity and uniform genome coverage. Here we will describe the following three fragmentation methods: restriction enzyme digestion, random shearing and nick translation. We will present the comparison results for these three methods. Our data showed that all three methods are able to generate paired-end libraries with greater than 20 kb insert. Advantages and disadvantages of these three methods will be discussed as well.
Dynamically Close Galaxy Pairs and Merger Rate Evolution in the CNOC2 Redshift Survey
D. R. Patton; C. J. Pritchet; R. G. Carlberg; R. O. Marzke; H. K. C. Yee; P. B. Hall; H. Lin; S. L. Morris; M. Sawicki; C. W. Shepherd; G. D. Wirth
2001-09-24
We investigate redshift evolution in the galaxy merger and accretion rates, using a well-defined sample of 4184 galaxies with 0.12 < z < 0.55 and R_C < 21.5. We identify 88 galaxies in close (5 < r_p < 20 h^{-1} kpc) dynamical (delta v < 500 km/s) pairs. These galaxies are used to compute global pair statistics, after accounting for selection effects resulting from the flux limit, k-corrections, luminosity evolution, and spectroscopic incompleteness. We find that the number of companions per galaxy (for -21 < M_B^{k,e} < -18) is Nc = 0.0321 +/- 0.0077 at z=0.3. The luminosity in companions, per galaxy, is Lc = 0.0294 +/- 0.0084 x 10^10 h^2 L_sun. We assume that Nc is proportional to the galaxy merger rate, while Lc is directly related to the mass accretion rate. After increasing the maximum pair separation to 50 h^{-1} kpc, and comparing with the low redshift SSRS2 pairs sample, we infer evolution in the galaxy merger and accretion rates of (1+z)^{2.3 +/- 0.7} and (1+z)^{2.3 +/- 0.9} respectively. These are the first such estimates to be made using only confirmed dynamical pairs. When combined with several additional assumptions, this implies that approximately 15% of present epoch galaxies with -21 < M_B < -18 have undergone a major merger since z=1.
Exactly solvable pairing model for superconductors with a p+ip-wave symmetry
Miguel Ibanez; Jon Links; German Sierra; Shao-You Zhao
2009-04-21
We present the exact Bethe ansatz solution for the two-dimensional BCS pairing Hamiltonian with p_x + i p_y symmetry. Using both mean-field theory and the exact solution we obtain the ground-state phase diagram parameterized by the filling fraction and the coupling constant. It consists of three phases denoted weak coupling BCS, weak pairing, and strong pairing. The first two phases are separated by a topologically protected line where the exact ground state is given by the Moore-Read pfaffian state. In the thermodynamic limit the ground-state energy is discontinuous on this line. The other two phases are separated by the critical line, also topologically protected, previously found by Read and Green. We establish a duality relation between the weak and strong pairing phases, whereby ground states of the weak phase are "dressed" versions of the ground states of the strong phase by zero energy (Moore-Read) pairs and characterized by a topological order parameter.
Mechanics and Dynamics of X-Chromosome Pairing at X Inactivation
A. Scialdone; M. Nicodemi
2009-10-13
At the onset of X Chromosomes Inactivation, the vital process whereby female mammal cells equalize X products with respect to males, the X chromosomes are colocalized along their Xic (X-Inactivation Center) regions. The mechanism inducing recognition and pairing of the X's remains, though, elusive. Starting from recent discoveries on the molecular factors and on the DNA sequences (the so-called ``pairing sites'') involved, we dissect the mechanical basis of Xic colocalization by using a Statistical Physics model. We show that soluble DNA specific binding molecules, as those experimentally identified, can be indeed sufficient to induce the spontaneous colocalization of the homologous chromosomes, but only when their concentration, or chemical affinity, rises above a threshold value, as a consequence of a thermodynamic phase transition. We derive the likelihood of pairing and its probability distribution. Chromosome dynamics has two stages: an initial independent Brownian diffusion followed, after a characteristic time scale, by recognition and pairing. Finally, we investigate the effects of DNA deletion/insertions in the region of pairing sites and compare model predictions to available experimental data.
Aaltonen, T.; Albin, E.; 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.; 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.; 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.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, 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.; Cho, K.; Chokheli, D.; Ciocci, M. A.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d’Ascenzo, N.; Datta, M.; De Barbaro, P.; Demortier, L.; Deninno, M.; Devoto, F.; d’Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D’Onofrio, M.; Donati, S.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Eusebi, R.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; 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.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; 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.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; 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.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, P.; Martínez, M.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; 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.; Ranjan, N.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sinervo, P.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Sorin, V.; Song, H.; Stancari, M.; Denis, R. St.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.
2013-07-01
We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We consider both nonresonant production via an intermediate gluon as well as resonant production via a distinct nonstandard-model intermediate strongly interacting particle. We use data collected by the CDF experiment in proton-antiproton collisions at ?s=1.96 TeV corresponding to an integrated luminosity of 6.6 fb?¹. We find the data to be consistent with nonresonant production. We report limits on ?(pp??jjjj) as a function of the masses of the hypothetical intermediate particles. Upper limits on the production cross sections for nonstandard-model particles in several resonant and nonresonant processes are also derived.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Aaltonen, T.; Albin, E.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; et al
2013-07-18
We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We consider both nonresonant production via an intermediate gluon as well as resonant production via a distinct nonstandard-model intermediate strongly interacting particle. We use data collected by the CDF experiment in proton-antiproton collisions at ?s=1.96 TeV corresponding to an integrated luminosity of 6.6 fb?¹. We find the data to be consistent with nonresonant production. We report limits on ?(pp??jjjj) as a function of the masses of themore »hypothetical intermediate particles. Upper limits on the production cross sections for nonstandard-model particles in several resonant and nonresonant processes are also derived.« less
I. Bentley; K. Neergård; S. Frauendorf
2014-03-20
A model with nucleons in a charge-independent potential well interacting by an isovector pairing force is considered. For a 24-dimensional valence space, the Hartree-Bogolyubov (HB) plus random phase approximation (RPA) to the lowest eigenvalue of the Hamiltonian is shown to be accurate except near values of the pairing force coupling constant G where the HB solution shifts from a zero to a non-zero pair gap. In the limit G -> infinity the HB + RPA is asymptotically exact. The inaccuracy of the HB + RPA in the critical regions of G can be remedied by interpolation. The resulting algoritm is used to calculate pairing corrections in the framework of a Nilsson-Strutinsky calculation of nuclear masses near N = Z for A = 24-100, where N and Z are the numbers of neutrons and protons, and A = N + Z. The dimension of the valence space is 2A in these calculations. Adjusting five liquid drop parameters and a power law expression for the constant G as a function of A allows us to reproduce the measured binding energies of 112 doubly even nuclei in this range with a root mean square deviation of 0.95 MeV. Several combinations of the masses for different N, Z, and isospin T are considered and the calculations found to be in good agreement with the data. It is demonstrated by examples how fluctuations as a function of A of the constant X in an expansion of the symmetry energy of the form T(T+X)/(2 theta) can be understood from the shell structure.
Search for pair-produced resonances decaying to jet pairs in proton-proton collisions at ?s = 8 TeV
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, Vardan
2015-07-01
Results are reported of a general search for pair production of heavy resonances decaying to pairs of jets in events with at least four jets. The study is based on up to 19.4 inverse femtobarns of integrated luminosity from proton-proton collisions at a center-of-mass energy of 8 TeV, recorded with the CMS detector at the LHC. Limits are determined on the production of scalar top quarks (top squarks) in the framework of R-parity violating supersymmetry and on the production of color-octet vector bosons (colorons). First limits at the LHC are placed on top squark production for two scenarios. The firstmore »assumes decay to a bottom quark and a light-flavor quark and is excluded for masses between 200 and 385 GeV, and the second assumes decay to a pair of light-flavor quarks and is excluded for masses between 200 and 350 GeV at 95% confidence level. Previous limits on colorons decaying to light-flavor quarks are extended to exclude masses from 200 to 835 GeV.« less
A Pair Production Telescope for Medium-Energy Gamma-Ray Polarimetry
Hunter , Stanley D.; Bloser, Peter F.; Depaola, Gerardo O.; Dion, Michael P.; DeNolfo, Georgia A.; Hanu, Andrei; Iparraguirre, Marcos; Legere, Jason; Longo, Francesco; McConnell, Mark L.; Nowicki, Suzanne F.; Ryan, James M.; Son, Seunghee; Stecker, Floyd W.
2014-08-01
We describe the science motivation and development of a pair production telescope for medium-13 energy gamma-ray polarimetry. Our instrument concept, the Advanced Energetic Pair Telescope 14 (AdEPT), takes advantage of the Three-Dimensional Track Imager, a low-density gaseous time 15 projection chamber, to achieve angular resolution within a factor of two of the pair production 16 kinematics limit (~0.6° at 70 MeV), continuum sensitivity comparable with the Fermi-LAT front 17 detector (<3×10-6 MeV cm-2 s-1 at 70 MeV), and minimum detectable polarization less than 10% 18 for a 10 millicrab source in 106 seconds.
The vacuum bubbles in de Sitter background and black hole pair creation
Bum-Hoon Lee; Wonwoo Lee
2009-10-07
We study the possible types of the nucleation of vacuum bubbles. We classify vacuum bubbles in de Sitter background and present some numerical solutions. The thin-wall approximation is employed to obtain the nucleation rate and the radius of vacuum bubbles. With careful analysis we confirm that Parke's formula is also applicable to the large true vacuum bubbles. The nucleation of the false vacuum bubble in de Sitter background is also evaluated. The tunneling process in the potential with degenerate vacua is analyzed as the limiting cases of the large true vacuum bubble and false vacuum bubble. Next, we consider the pair creation of black holes in the background of bubble solutions. We obtain static bubble wall solutions of junction equation with black hole pair. The masses of created black holes are uniquely determined by the cosmological constant and surface tension on the wall. Finally, we obtain the rate of pair creation of black holes.
Krawtchouk polynomials, the Lie algebra $\\mathfrak{sl}_2$, and Leonard pairs
Nomura, Kazumasa
2012-01-01
A Leonard pair is a pair of diagonalizable linear transformations of a finite-dimensional vector space, each of which acts in an irreducible tridiagonal fashion on an eigenbasis for the other one. In the present paper we give an elementary but comprehensive account of how the following are related: (i) Krawtchouk polynomials; (ii) finite-dimensional irreducible modules for the Lie algebra ${\\mathfrak{sl}_2}$; (iii) a class of Leonard pairs said to have Krawtchouk type. Along the way we obtain elementary proofs of some well-known facts about Krawtchouk polynomials, such as the three-term recurrence, the orthogonality, the difference equation, and the generating function. The paper is a tutorial meant for a graduate student or a researcher unfamiliar with the above topics.
Tunable cavity-enhanced photon pairs source in Hermite-Gaussian mode
Zhou, Zhi-Yuan; Ding, Dong-Sheng; Zhang, Wei; Shi, Shuai; Shi, Bao-Sen; Guo, Guang-Can
2015-01-01
The spatial modes of light have grasped great research interests because of its great potentials in optical communications, optical manipulation and trapping, optical metrology and quantum information processing. Here we report on generating of photon pairs in Hermite-Gaussian (HG) mode in a type-I optical parametric oscillator (OPO) operated far below threshold. The bandwidths of the photon pairs are 11.4 MHz and 20.8MHz for two different HG modes respectively, which is capable to be stored in cold Rubidium atomic ensembles. From correlation measurements, non-classical properties of HG modes in different directions are verified by tuning the cavity. Our study provides an effective way to generate photon pairs with narrow bandwidth in high order spatial modes for high dimensional quantum communication.
Statistics of simulated and observed pair separations in the Gulf of Mexico
Beron-Vera, F J
2015-01-01
Pair-separation statistics of in-situ and synthetic surface drifters deployed near the \\emph{Deepwater Horizon} site in the Gulf of Mexico are investigated. The synthetic trajectories derive from synthetic particles advected by surface velocities from a 1-km-resolution data-assimilative Navy Coastal Ocean Model (NCOM) simulation. The in-situ drifters were launched in the Grand LAgrangian Deployment (GLAD). The statistical measures are of two classes---those which are functions of time, including the probability distribution function (PDF) of pair separations, the relative dispersion and the kurtosis, and those which are functions of separation, including the second-order velocity structure function and the relative diffusivity. The measures yield a consistent picture of the dispersion with the simulated pairs, with nonlocal dispersion from separations of 1 km to the Rossby deformation radius, $L_\\mathrm{D}$, and diffusive dispersion above $L_\\mathrm{D}$. The measures are less consistent with the GLAD drifters...
Long-range Cooper pair splitter with high entanglement production rate
Wei Chen; D. N. Shi; D. Y. Xing
2015-01-05
Cooper pairs in the superconductor are a natural source of spin entanglement. The existing proposals of the Cooper pair splitter can only realize a low efficiency of entanglement production, and its size is constrained by the superconducting coherence length. Here we show that a long-range Cooper pair splitter can be implemented in a normal metal-superconductor-normal metal (NSN) junction by driving a supercurrent in the S. The supercurrent results in a band gap modification of the S, which significantly enhances the crossed Andreev reflection (CAR) of the NSN junction and simultaneously quenches its elastic cotunneling. Therefore, a high entanglement production rate close to its saturation value can be achieved by the inverse CAR. Interestingly, in addition to the conventional entangled electron states between opposite energy levels, novel entangled states with equal energy can also be induced in our proposal.
Coherent chemical kinetics as quantum walks II: Radical-pair reactions in Arabidopsis thaliana
A. Chia; A. Gorecka; P. Kurzynski; T. Paterek; D. Kaszlikowski
2015-08-20
We apply the quantum-walk approach recently proposed in arXiv:quant-ph-1506.04213 to a radical-pair reaction where realistic estimates for the intermediate transition rates are available. The well-known average hitting time from quantum walks can be adopted as a measure of how quickly the reaction occurs and we calculate this for varying degrees of dephasing in the radical pair. The time for the radical pair to react to a product is found to be independent of the amount of dephasing introduced, even in the limit of no dephasing where the transient population dynamics exhibit strong coherent oscillations. This can be seen to arise from the existence of a rate-limiting step in the reaction and we argue that in such examples, a purely classical model based on rate equations can be used for estimating the timescale of the reaction but not necessarily its population dynamics.
Direct generation of genuine single-longitudinal-mode narrowband photon pairs
Luo, Kai-Hong; Krapick, Stephan; Brecht, Benjamin; Ricken, Raimund; Quiring, Viktor; Suche, Hubertus; Sohler, Wolfgang; Silberhorn, Christine
2015-01-01
The practical prospect of quantum communication and information processing relies on sophisticated single photon pairs which feature controllable waveform, narrow spectrum, excellent purity, fiber compatibility and miniaturized design. For practical realizations, stable, miniaturized, low-cost devices are required. Sources with one or some of above performances have been demonstrated already, but it is quite challenging to have a source with all of the described characteristics simultaneously. Here we report on an integrated single-longitudinal-mode non-degenerate narrowband photon pair source, which exhibits all requirements needed for quantum applications. The device is composed of a periodically poled Ti-indiffused lithium niobate waveguide with high reflective dielectric mirror coatings deposited on the waveguide end-faces. Photon pairs with wavelengths around 890 nm and 1320 nm are generated via type II phase-matched parametric down-conversion. Clustering in this dispersive cavity restricts the whole con...
The radical-pair mechanism as a paradigm for the emerging science of quantum biology
Kominis, I K
2015-01-01
The radical-pair mechanism was introduced in the 1960's to explain anomalously large EPR and NMR signals in chemical reactions of organic molecules. It has evolved to the cornerstone of spin chemistry, the study of the effect electron and nuclear spins have on chemical reactions, with the avian magnetic compass mechanism and the photosynthetic reaction center dynamics being prominent biophysical manifestations of such effects. In recent years the radical-pair mechanism was shown to be an ideal biological system where the conceptual tools of quantum information science can be fruitfully applied. We will here review recent work making the case that the radical-pair mechanism is indeed a major driving force of the emerging field of quantum biology.
Observable effects caused by vacuum pair creation in the field of high-power optical lasers
David B. Blaschke; Andrey V. Filatov; Irina A. Egorova; Alexander V. Prozorkevich; Stanislav A. Smolyansky
2008-11-29
We consider the possibility of an experimental proof of vacuum e+e- pair creation in the focus of two counter-propagating optical laser beams with an intensity of the order of 10^20 - 10^22 W/cm^2. Our approach is based on the collisionless kinetic equation for the distribution function of the e+e- pairs with the source term for particle production. As a possible experimental signal of vacuum pair production we consider the refraction of a high-frequency probe laser beam by the produced e+e- plasma to be observed by an interference filter. The generation of higher harmonics of the laser frequency in the self-consistent electric field is also investigated.
Energy loss of intergalactic pair beams: Particle-in-Cell simulation
Kempf, Andreas; Spanier, Felix
2015-01-01
The change of the distribution function of electron-positron pair beams determines whether GeV photons can be produced as secondary radiation from TeV photons. We will discuss the instabilities driven by pair beams. The system of a thermal proton-electron plasma and the electron-positron beam is collision free. We have, therefore, used the Particle-in-Cell simulation approach. It was necessary to alter the physical parameters, but the ordering of growth rates has been retained. We were able to show that plasma instabilities can be recovered in particle-in-cell simulations, but their effect on the pair distribution function is negligible for beam-background energy density ratios typically found in blazars.
Synchrotron and inverse-Compton emissions from pairs formed in GRB afterglows (analytical treatment)
Panaitescu, A.; Vestrand, W. T. [Space and Remote Sensing, MS B244, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2014-10-01
We calculate the synchrotron and inverse-Compton emissions from pairs formed in gamma-ray burst (GRB) afterglows from high-energy photons (above 100 MeV), assuming a power-law photon spectrum C {sub ?}??{sup –2} and considering only the pairs generated from primary high-energy photons. The essential properties of these pairs (number, minimal energy, cooling energy, distribution with energy) and of their emission (peak flux, spectral breaks, spectral slope) are set by the observables GeV fluence ?(t) = Ft and spectrum, and by the Lorentz factor, ?, and magnetic field, B, of the source of high-energy photons, at observer time, t. Optical and X-ray pseudo light curves, F {sub ?}(?), are calculated for the given B; proper synchrotron self-Compton light curves are calculated by setting the dynamics ?(t) of the high-energy photon source to be that of a decelerating, relativistic shock. It is found that the emission from pairs can accommodate the flux and decays of the optical flashes measured during the prompt (GRB) phase, but it decays faster than the X-ray plateaus observed during the delayed (afterglow) phase. The brightest pair optical emission is obtained for 100 < ? < 500, and depends mostly on the GeV fluence, being independent of the source redshift. Emission from pairs formed during the GRB phase offers an alternate explanation to reverse-shock optical flashes. These two models may be distinguished based on their corresponding flux decay index-spectral slope relations, different correlations with the Large Area Telescope fluence, or through modeling of the afterglow multiwavelength data.
Conversion of relativistic pair energy into radiation in the jets of active galactic nuclei
R. Schlickeiser; R. Vainio; M. Boettcher; I. Lerche; M. Pohl; C. Schuster
2002-07-02
It is generally accepted that relativistic jet outflows power the nonthermal emission from active galactic nuclei (AGN). The composition of these jets -- leptonic versus hadronic -- is still under debate. We investigate the microphysical details of the conversion process of the kinetic energy in collimated relativistic pair outflows into radiation through interactions with the ambient interstellar medium. Viewed from the coordinate system comoving with the pair outflow, the interstellar protons and electrons represent a proton-electron beam propagating with relativistic speed in the pair plasma. We demonstrate that the beam excites both electrostatic and low-frequency magnetohydrodynamic Alfven-type waves via a two-stream instability in the pair background plasma, and we calculate the time evolution of the distribution functions of the beam particles and the generated plasma wave turbulence power spectra. For standard AGN jet outflow and environment parameters we show that the initial beam distributions of interstellar protons and electrons quickly relax to plateau-distributions in parallel momentum, transferring thereby one-half of the initial energy density of the beam particles to electric field fluctuations of the generated electrostatic turbulence. On considerably longer time scales, the plateaued interstellar electrons and protons will isotropise by their self-generated transverse turbulence and thus be picked-up in the outflow pair plasma. These longer time scales are also characteristic for the development of transverse hydromagnetic turbulence from the plateaued electrons and protons. This hydromagnetic turbulence upstream and downstream is crucial for diffusive shock acceleration to operate at external or internal shocks associated with pair outflows.
A CLOSE-PAIR ANALYSIS OF DAMP MERGERS AT INTERMEDIATE REDSHIFTS
Chou, Richard C. Y.; Abraham, Roberto G.; Bridge, Carrie R. E-mail: abraham@astro.utoronto.ca
2012-12-01
We have studied the kinematics of {approx}2800 candidate close-pair galaxies at 0.1 < z < 1.2 identified from the Canada-France-Hawaii Telescope Legacy Survey fields. Spectra of these systems were obtained using spectrometers on the 6.5 m Magellan and 5 m Hale telescopes. These data allow us to constrain the rate of dry mergers at intermediate redshifts and to test the 'hot halo' model for quenching of star formation. Using virial radii estimated from the correlation between dynamical and stellar masses published by Leauthaud et al., we find that around 1/5 of our candidate pairs are likely to share a common dark matter halo (our metric for close physical association). These pairs are divided into red-red, blue-red, and blue-blue systems using the rest-frame colors classification method introduced in Chou et al.. Galaxies classified as red in our sample have very low star formation rates, but they need not be totally quiescent, and hence we refer to them as 'damp', rather than 'dry', systems. After correcting for known selection effects, the fraction of blue-blue pairs is significantly greater than that of red-red and blue-red pairs. Red-red pairs are almost entirely absent from our sample, suggesting that damp mergers are rare at z {approx} 0.5. Our data support models with a short merging timescale (<0.5 Gyr) in which star formation is enhanced in the early phase of mergers, but quenched in the late phase. Hot halo models may explain this behavior, but only if virial shocks that heat gas are inefficient until major mergers are nearly complete.
Discovering Higgs boson pair production through rare final states at a 100 TeV collider
Papaefstathiou, Andreas
2015-01-01
We consider Higgs boson pair production at a future proton collider with centre-of-mass energy of 100 TeV, focusing on rare final states that include a bottom-anti-bottom quark pair and multiple isolated leptons: $hh \\rightarrow (b\\bar{b}) + n \\ell + X$, $n = \\{2,4\\}$, $X = \\{ E_T^\\mathrm{miss}, \\gamma, -\\}$. We construct experimental search strategies for observing the process through these channels and make suggestions on the desired requirements for the detector design of the future collider.
Equal-spin pairing state of superfluid {sup 3}He in aerogel
Aoyama, Kazushi; Ikeda, Ryusuke [Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan)
2005-07-01
The equal-spin pairing state, the so-called A-like phase, of superfluid {sup 3}He in aerogels is studied theoretically in the Ginzburg-Landau region by examining thermodynamics, and the resulting equilibrium phase diagram is mapped out. We find that the ABM pairing state with presumably quasi-long-ranged superfluid order has a lower free energy than the planar and 'robust' states and is the best candidate of the A-like phase with a strange lowering of the polycritical point observed experimentally.
Quantum heat engine based on photon-assisted Cooper pair tunneling
Patrick P. Hofer; J. -R. Souquet; Aashish A. Clerk
2015-12-07
We propose and analyze a simple mesoscopic quantum heat engine that exhibits both high-power and high-efficiency. The system consists of a biased Josephson junction coupled to two microwave cavities, with each cavity coupled to a thermal bath. Resonant Cooper pair tunnelling occurs with the exchange of photons between cavities, and a temperature difference between the baths can naturally lead to a current against the voltage, and hence work. As a consequence of the unique properties of Cooper-pair tunneling, the heat current is completely separated from the charge current. This combined with the strong energy-selectivity of the process leads to an extremely high efficiency.
Shape and pairing fluctuations effects on neutrinoless double beta decay nuclear matrix elements
Nuria López Vaquero; Tomás R. Rodríguez; J. Luis Egido
2014-01-03
Nuclear matrix elements (NME) for the most promising candidates to detect neutrinoless double beta decay have been computed with energy density functional methods including deformation and pairing fluctuations explicitly on the same footing. The method preserves particle number and angular momentum symmetries and can be applied to any decay without additional fine tunings. The finite range density dependent Gogny force is used in the calculations. An increase of $10\\%-40\\%$ in the NME with respect to the ones found without the inclusion of pairing fluctuations is obtained, reducing the predicted half-lives of these isotopes.
Time-bin entangled photon pair generation from Si micro-ring resonator
Ryota Wakabayashi; Mikio Fujiwara; Ken-ichiro Yoshino; Yoshihiro Nambu; Masahide Sasaki; Takao Aoki
2015-01-23
We demonstrate time-bin entanglement generation in telecom wavelength using a 7 {\\mu}m radius Si micro-ring resonator pumped by a continuous wave laser. The resonator structure can enhance spontaneous four wave mixing, leading to a photon pair generation rate of about 90-100 Hz with a laser pump power of as low as -3.92 dBm (0.41 mW). We succeed in observing time-bin entanglement with the visibility over 92%. Moreover, wavelength-tunability of the entangled photon pair is demonstrated by changing the operation temperature.
Power-efficient production of photon pairs in a tapered chalcogenide microwire
Meyer-Scott, Evan; Ahmad, Raja; Li, Lizhu; Rochette, Martin; Jennewein, Thomas
2015-01-01
Using tapered fibers of As2Se3 chalcogenide glass, we produce photon pairs at telecommunication wavelengths with pump power as low as 250 nW for a single pump, and 191 nW for the weak pump in a two-pump non-degenerate scheme. Our results show that the ultrahigh nonlinearity in these microwires could allow single-photon pumping to produce photon pairs, enabling the production of large entangled states, heralding of single photons after lossy transmission, and photonic quantum information processing with nonlinear optics.
Many-body systems in the presence of the random interaction and the $J$ pairing interaction
A. Arima
2004-05-26
In this talk I shall discuss some regularities of many-body systems in the presence of random interactions and regularities of a single-$j$ shell for the $J$ pairing interaction which works only when two particles are coupled to spin $J$. I shall first explain an empirical rule to predict the spin $I$ ground state probability. Then I shall present some interesting results of a single-$j$ shell under the $J$ pairing interaction. Last I shall discuss some preliminary results of binding energies in the presence of random two-body interactions.
Spin polarized electron-positron pair production via elliptical polarized laser fields
Wöllert, Anton; Keitel, Christoph H
2015-01-01
We study nonperturbative multiphoton electron-positron pair creation in ultra-strong electromagnetic fields formed by two counterpropagating pulses with elliptic polarization. Our numerical approach allows us to take into account the temporal as well as the spatial variation of the standing electromagnetic field. The spin and momentum resolved pair creation probabilities feature characteristic Rabi oscillations and resonance spectra. Therefore, each laser frequency features a specific momentum distribution of the created particles. We find that depending on the relative polarization of both pulses the created electrons may be spin polarized along the direction of field propagation.
Non-QCD contributions to top-pair production near threshold
Martin Beneke; Andreas Maier; Jan Piclum; Thomas Rauh
2015-11-03
The threshold scan of top pair production at a future lepton collider allows to determine several Standard Model parameters with very high precision. The recent completion of the third-order QCD corrections to the inclusive top-pair production cross section demonstrated that strong dynamics are under control. We investigate effects from P-wave production and Higgs contributions at third order and from QED and the nonresonant production of the physical $W^+W^-b\\bar{b}$ final state at first order. We discuss the sensitivity of the cross section to the top mass, width and Yukawa coupling as well as to the strong coupling.
Nuclear pairing from bare interaction: Two and three-body chiral forces
Finelli, Paolo
2012-10-20
In a recent paper the {sup 1}S{sub 0} pairing gap in isospin-symmetric nuclear matter and finite nuclei has been investigated starting from the chiral nucleon-nucleon potential at the N{sup 3}LO order in the two-body sector and the N{sup 2}LO order in the three-body sector. To include realistic nuclear forces in RHB (Relativistic Hartree Bolgoliubov) calculations we relied on a separable representation of the pairing interaction. In this paper we would like to show recent results concerning isotonic chains with N= 28,50,82.
Study of correlations between photoproduced pairs of charmed particles at Experiment E831/FOCUS
Castromonte Flores, Cesar Manuel; /Rio de Janeiro, CBPF
2008-08-01
The authors present the study of the charm-pair correlations produced in photon-nucleon interactions at
Compositions of orthogonal lysyl-tRNA and aminoacyl-tRNA synthetase pairs and uses thereof
Anderson, J. Christopher (San Francisco, CA); Wu, Ning (Brookline, MA); Santoro, Stephen (Cambridge, MA); Schultz, Peter G. (La Jolla, CA)
2009-08-18
Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal lysyl-tRNAs, orthogonal lysyl-aminoacyl-tRNA synthetases, and orthogonal pairs of lysyl-tRNAs/synthetases, which incorporate homoglutamines into proteins are provided in response to a four base codon. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with homoglutamines using these orthogonal pairs.
Compositions of orthogonal lysyl-tRNA and aminoacyl-tRNA synthetase pairs and uses thereof
Anderson, J. Christopher (San Francisco, CA); Wu, Ning (Brookline, MA); Santoro, Stephen (Cambridge, MA); Schultz, Peter G. (La Jolla, CA)
2011-10-04
Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal lysyl-tRNAs, orthogonal lysyl-aminoacyl-tRNA synthetases, and orthogonal pairs of lysyl-tRNAs/synthetases, which incorporate homoglutamines into proteins are provided in response to a four base codon. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with homoglutamines using these orthogonal pairs.
Compositions of orthogonal lysyl-tRNA and aminoacyl-tRNA synthetase pairs and uses thereof
Anderson, J. Christopher (San Francisco, CA); Wu, Ning (Brookline, MA); Santoro, Stephen (Cambridge, MA); Schultz, Peter G. (La Jolla, CA)
2009-12-29
Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal lysyl-tRNAs, orthogonal lysyl-aminoacyl-tRNA synthetases, and orthogonal pairs of lysyl-tRNAs/synthetases, which incorporate homoglutamines into proteins are provided in response to a four base codon. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with homoglutamines using these orthogonal pairs.
Compositions of orthogonal lysyl-tRNA and aminoacyl-tRNA synthetase pairs and uses thereof
Anderson, J. Christopher; Wu, Ning; Santoro, Stephen; Schultz, Peter G
2014-03-11
Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal lysyl-tRNAs, orthogonal lysyl-aminoacyl-tRNA synthetases, and orthogonal pairs of lysyl-tRNAs/synthetases, which incorporate homoglutamines into proteins are provided in response to a four base codon. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with homoglutamines using these orthogonal pairs.
Continuous-wave quasi-phase-matched waveguide correlated photon pair source on a III–V chip
Sarrafi, Peyman Zhu, Eric Y.; Dolgaleva, Ksenia; Aitchison, J. Stewart; Qian, Li; Holmes, Barry M.; Hutchings, David C.
2013-12-16
We report on the demonstration of correlated photon pair generation in a quasi-phase-matched superlattice GaAs/AlGaAs waveguide using a continuous-wave pump. Our photon pair source has a low noise level and achieves a high coincidence-to-accidental ratio greater than 100, which is the highest value reported in III–V chips so far. This correlated photon pair source has the potential to be monolithically integrated with on-chip pump laser sources fabricated on the same superlattice wafer structure, enabling direct correlated/entangled photon pair production from a compact electrically powered chip.
A. Rabhi
2003-07-17
We comment on a recent application of the RPA method and its extensions to the case of the two-level pairing model by N. Dinh Dang [1].
RELATIVE ORIENTATION OF PAIRS OF SPIRAL GALAXIES IN THE SLOAN DIGITAL SKY SURVEY
Buxton, Jesse; Ryden, Barbara S., E-mail: buxton.45@osu.edu, E-mail: ryden@astronomy.ohio-state.edu [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)
2012-09-10
From our study of binary spiral galaxies in the Sloan Digital Sky Survey Data Release 6, we find that the relative orientation of disks in binary spiral galaxies is consistent with their being drawn from a random distribution of orientations. For 747 isolated pairs of luminous disk galaxies, the distribution of {phi}, the angle between the major axes of the galaxy images, is consistent with a uniform distribution on the interval [0 Degree-Sign , 90 Degree-Sign ]. With the assumption that the disk galaxies are oblate spheroids, we can compute cos {beta}, where {beta} is the angle between the rotation axes of the disks. In the case that one galaxy in the binary is face-on or edge-on, the tilt ambiguity is resolved, and cos {beta} can be computed unambiguously. For 94 isolated pairs with at least one face-on member, and for 171 isolated pairs with at least one edge-on member, the distribution of cos {beta} is statistically consistent with the distribution of cos i for isolated disk galaxies. This result is consistent with random orientations of the disks within pairs.
Donor-vacancy pairs in irradiated n-Ge: A searching look at the problem
Emtsev, Vadim; Oganesyan, Gagik [IoffePhysicotechnical Institute, Russian Academy of Sciences, Politekhnicheskaya ulitsa 26, 194021 St. Petersburg (Russian Federation)
2014-02-21
The present situation concerning the identification of vacancy-donor pairs in irradiated n-Ge is discussed. The challenging points are the energy states of these defects deduced from DLTS spectra. Hall effect data seem to be at variance with some important conclusions drawn from DLTS measurements. Critical points of the radiation-produced defect modeling in n-Ge are highlighted.
Prioritized interaction testing for pair-wise coverage with seeding and constraints q
Bryce, Renee
them in the earliest tests of a test suite. A test case prioritization problem is formally definedPrioritized interaction testing for pair-wise coverage with seeding and constraints q Rene´e C 85287-8809, USA Received 27 February 2006; accepted 21 March 2006 Available online 4 May 2006 Abstract
Some Experiments in Mining Named Entity Transliteration Pairs from Comparable Corpora
Microsoft Research India Bangalore, India v-sarak@microsoft.com A Kumaran Microsoft Research India Bangalore, India kumarana@microsoft.com Abstract Parallel Named Entity pairs are important resources in several NLP, more recently, statistical machine learning techniques have been shown to be effec- tive
Model Calculations of Protein Pair Interference Functions P. B. MOORE AND D. I~. ENGELMAN
of the interference cross term, derived from neutron scattering studies of structures containing pairs of deuterated by the neutron scattering method, and should help clarify the interpretation of such data. A2. Method Our and -~2 are the radii of the spheres in question, px and p2 are their respective scattering densities
Anomalous pairing vibration in neutron-rich Sn isotopes beyond the N=82 magic number
Hirotaka Shimoyama; Masayuki Matsuo
2011-06-09
Two-neutron transfer associated with the pair correlation in superfluid neutron-rich nuclei is studied with focus on low-lying $0^+$ states in Sn isotopes beyond the N=82 magic number. We describe microscopically the two-neutron addition and removal transitions by means of the Skyrme-Hartree-Fock-Bogoliubov mean-field model and the continuum quasiparticle random phase approximation formulated in the coordinate space representation. It is found that the pair transfer strength for the transitions between the ground states becomes significantly large for the isotopes with $A \\ge 140$, reflecting very small neutron separation energy and long tails of the weakly bound $3p$ orbits. In $^{132-140}$Sn, a peculiar feature of the pair transfer is seen in transitions to low-lying excited $0^+$ states. They can be regarded as a novel kind of pair vibrational mode which is characterized by an anomalously long tail of the transition density extending to far outside of the nuclear surface, and a large strength comparable to that of the ground-state transitions. The presence of the weakly bound neutron orbits plays a central role for these anomalous behaviors.
Search for the associated production of the Higgs boson with a top-quark pair
CMS Collaboration
A search for the standard model Higgs boson produced in association with a top-quark pair (tt¯H) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb?1 and 19.7 fb?1 collected in pp ...
Dynamically Close Galaxy Pairs and Merger Rate Evolution in the CNOC2 Redshift Survey
Patton, D R; Carlberg, R G; Marzke, R O; Yee, H K C; Hall, P B; Lin, H; Morris, S L; Sawicki, M; Shepherd, C W; Wirth, G D
2001-01-01
We investigate redshift evolution in the galaxy merger and accretion rates, using a well-defined sample of 4184 galaxies with 0.12 < z < 0.55 and R_C < 21.5. We identify 88 galaxies in close (5 < r_p < 20 h^{-1} kpc) dynamical (delta v < 500 km/s) pairs. These galaxies are used to compute global pair statistics, after accounting for selection effects resulting from the flux limit, k-corrections, luminosity evolution, and spectroscopic incompleteness. We find that the number of companions per galaxy (for -21 < M_B^{k,e} < -18) is Nc = 0.0321 +/- 0.0077 at z=0.3. The luminosity in companions, per galaxy, is Lc = 0.0294 +/- 0.0084 x 10^10 h^2 L_sun. We assume that Nc is proportional to the galaxy merger rate, while Lc is directly related to the mass accretion rate. After increasing the maximum pair separation to 50 h^{-1} kpc, and comparing with the low redshift SSRS2 pairs sample, we infer evolution in the galaxy merger and accretion rates of (1+z)^{2.3 +/- 0.7} and (1+z)^{2.3 +/- 0.9} r...
Cut-wire-pair structures as two-dimensional magnetic metamaterials
Cut-wire-pair structures as two-dimensional magnetic metamaterials David A. Powell, Ilya V-dimensional metamaterial suitable for scaling to optical frequencies. We fabricate the cut-wire metamaterial operating. © 2008 Optical Society of America OCIS codes: (160.3918) Metamaterials; (350.4010) Microwaves References
Measurement of prompt J/? pair production in pp collisions at ?s = 7 Tev
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, Vardan
2014-09-17
Production of prompt J/? meson pairs in proton-proton collisions at ?s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb?¹. The two J/? mesons are fully reconstructed via their decays into ?? ?? pairs. This observation provides for the first time access to the high-transverse-momentum region of J/? pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/? transverse momentum (pTJ/?) and rapidity (|yJ/?|): |yJ/?| more »pTJ/? > 6.5 GeV/c, 1.2 J/?| T threshold that scales linearly with |yJ/?| from 6.5 to 4.5 GeV/c, and 1.43 J/?| TJ/? > 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/? pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/? polarization imply modifications to the cross section ranging from -31% to +27%.« less
AER EAR: A Matched Silicon Cochlea Pair with Address Event Representation Interface
Liu, Shih-Chii
AER EAR: A Matched Silicon Cochlea Pair with Address Event Representation Interface André van, the Address Event Representation (AER) interface has become the standard interface protocol in recent years. The AER approach allows us to model biological systems using discrete level (spikes) and continuous
Use of Exchangeable Pairs in the Analysis of Simulations Charles Stein with
labels (the so-called magnetization), direct or theoretical evaluation of EW is impossible e.g. when N are introduced. The relation with reversible Markov chains is recalled. A basic identity for an exchangeable pair (Stein [23]) and to derive combinatorial formulae for balls and boxes and cycle lengths in random
WiseUp! Smart Tag Pairing Evolves and Persists CPM Working Paper 0290 (version 1)
Hales, David
WiseUp! Smart Tag Pairing Evolves and Persists CPM Working Paper 0290 (version 1) David Hales with ``smart'' searching strategies outperformed populations of ``dumb'' (random) search strategies -- even when the costs of smart searching were much higher. We hypothesised that in mixed populations smart
Pairing-Based Onion Routing Aniket Kate, Greg Zaverucha, and Ian Goldberg
Goldberg, Ian
. #12;2. We use our protocol to build onion routing circuits for anonymity networks like Tor [7]. OurPairing-Based Onion Routing Aniket Kate, Greg Zaverucha, and Ian Goldberg David R. Cheriton School in onion routing anonymity networks. Instead of iteratively and interactively constructing circuits
A Standard Reference Frame for the Description of Nucleic Acid Base-pair Geometry
Gerstein, Mark
uncertainties in this data set closely match numerical values reported in the recent survey of nucleic acid baseA Standard Reference Frame for the Description of Nucleic Acid Base-pair Geometry These preliminary (Rockefeller University), Richard E. Dickerson (University of California, Los Angeles), Mark Gerstein (Yale
Directed evolution of specific receptorligand pairs for use in the creation of gene switches
Zhao, Huimin
Directed evolution of specific receptorligand pairs for use in the creation of gene switches in the creation of gene switches for the control of heterologous gene expression in applications such as gene switch-like'' attributes: rapid induction kinetics (68), dose-dependent ligand response, and readily
First Observation of Vector Boson Pairs in a Hadronic Final State at the Tevatron Collider
Paus, Christoph M. E.
We present the first observation in hadronic collisions of the electroweak production of vector boson pairs (VV, V=W, Z) where one boson decays to a dijet final state. The data correspond to 3.5??fb[superscript -1] of ...
Chan, Yingguang
METHODS Fish sampling Threespine sticklebacks of the Japanese sympatric pair were collected- 2008, as described previously19,36 . Fish collected in 2007 and 2008 were used for cytogenetic analysis, fish collected in 2006 and 2007 were used for population genetic analysis, fish collected in 2005, 2007
Next-to-leading order QCD corrections to light Higgs Pair production via vector boson fusion
Terrance Figy
2008-06-15
We present the NLO QCD corrections for light Higgs pair production via vector boson fusion at the LHC within the CP conserving type II two higgs doublet model in the form of a fully flexible parton--level Monte Carlo program. Scale dependences on integrated cross sections and distributions are reduced with QCD K-factors of order unity.
QCD Corrections to Vector Boson Pair Production via Weak Boson Fusion
B. Jager; C. Oleari; D. Zeppenfeld
2006-08-24
NLO-QCD corrections to vector boson pair production via weak boson fusion have recently been calculated and implemented into flexible parton-level Monte-Carlo programs. These allow for the computation of cross sections and kinematical distributions within realistic experimental cuts. We summarize the basic elements of the calculation and review phenomenological results for the LHC.
A Pipelined Karatsuba-Ofman Multiplier over GF(397 Amenable for Pairing Computation
International Association for Cryptologic Research (IACR)
A Pipelined Karatsuba-Ofman Multiplier over GF(397 ) Amenable for Pairing Computation Nidia Cortez several field multiplications need to be computed at once, we decided to design a k-stage pipeline four-stage pipeline design can perform more than one field mul- tiplication per clock cycle. When
Crossing-over in rearranging chromosomes of Drosophila: The role of delayed pairing
Chadov, B.F.; Chadova, E.V.; Khotskina, E.A.
1995-11-01
A Df(2R)MS2-10 deletion of pericentromeric heterochromatin and an Is(Y;2L)419 insertion of Y material in the region 34A, as well as nondisjunction of chromosomes 2 in 2/F(2L); F(2R) females did not directly prevent chromosome arms in chromosome 2 of Drosophila from pairing. However, these events resulted in (1) two- to four-fold decrease in the rate of crossing-over in chromosome 2; (2) a decreased proportion of exchange tetrads two to three times greater for multiple-exchange tetrads than for single-exchange ones; and (3) a decreased rate of crossing-over throughout the entire chromosome arm enhanced in a proximal direction. An In(1)dl-49+B{sup M1}inversion in the X chromosome cancelled the suppression of crossing-over. Crossing-over increased due to an increasing proportion of single-exchange tretrads. The changes in crossing-over found cannot be explained by asynapsis in the chromosomes with rearrangements. According to the authors, these changes are probably accounted for by a delayed pairing of these chromosomes. The delayed pairing of individual chromosome regions or the whole chromosome is considered the most common type of pairing disturbance. It effects on meiosis are discussed. 39 refs., 6 figs., 1 tab.
Preparing photon pairs entangled in any desired spatial modes via interference
Galvez, Enrique J. "Kiko"
Department of Physics and Astronomy, Colgate University, 13 Oak Drive, Hamilton, New York 13346, U in energy-momentum,1 polarization,2,3 and spatial mode.4 Spatial-mode entanglement involves the use high, but not the only alternative. After the spatial filter the pairs are in a product state: |u = |u0 1|u0 2. (2
Search for pair production of excited top quarks in the lepton + jets final state
Apyan, Aram
A search is performed for pair-produced spin-3/2 excited top quarks (t[superscript ?][¯ over t][superscript ?]), each decaying to a top quark and a gluon. The search uses data collected with the CMS detector from pp ...
Scalable, Server-Passive, User-Anonymous Timed Release Public Key Encryption from Bilinear Pairing
International Association for Cryptologic Research (IACR)
Scalable, Server-Passive, User-Anonymous Timed Release Public Key Encryption from Bilinear Pairing- able, server-passive and user-anonymous timed release public-key encryption scheme which allows precise in our scheme is completely passive -- no interaction between it and the sender or receiver is needed
Review Short-term irradiance variability: Preliminary estimation of station pair correlation the irradiance variability observed at two neighboring sites as a function of their distance of the considered time scale. Ó 2012 Elsevier Ltd. All rights reserved. Keywords: Irradiance; Variability; High
Hardware Accelerator for the Tate Pairing in Characteristic Three Based on
Detrey, Jérémie
, 07300 M´exico City, M´exico Abstract. This paper is devoted to the design of fast parallel accel propose here a novel hardware imple- mentation of Miller's loop based on a pipelined Karatsuba-Ofman multi to the Tate pairing, we manage to keep the pipeline busy. We also describe the strategies we considered
Electron-positron pair production by linearly polarized photon in the nuclear field
Bakmaev, S; Peresunko, Yu P; Shapoval, I; Peresunko, Yu. P.
2008-01-01
Process of lepton pair production by polarized photon can be used to measure the degree of linear polarization of high energy photon. The differential cross section and the analyzing power are calculated with taking into account higher powers of expansion on $Z\\alpha$. Pure Coulomb and screened potential are considered.
Scaling properties of the pairing problem in the strong coupling limit
Barbaro, M.B.; Cenni, R.; Molinari, A.; Quaglia, M.R.
2013-10-15
We study the excited states of the pairing Hamiltonian providing an expansion for their energy in the strong coupling limit. To assess the role of the pairing interaction we apply the formalism to the case of a heavy atomic nucleus. We show that only a few statistical moments of the level distribution are sufficient to yield an accurate estimate of the energy for not too small values of the coupling G and we give the analytic expressions of the first four terms of the series. Further, we discuss the convergence radius G{sub sing} of the expansion showing that it strongly depends upon the details of the level distribution. Furthermore G{sub sing} is not related to the critical values of the coupling G{sub crit}, which characterize the physics of the pairing Hamiltonian, since it can exist even in the absence of these critical points. -- Highlights: •We study the excitation spectrum of the pairing Hamiltonian. •We provide an analytic expansion around the strong coupling limit. •We discuss the convergence radius of the expansion. •We connect the radius with the critical points of H.
Eeckhout, Lieven
for the given benchmark. This method- ology is validated by showing that program-input pairs that are close in the impact of input data sets on program behavior and profile-guided compiler optimizations. 1 Introduction product [1, 7]. A work- load then typically consists of a number of benchmarks with respective input data
Pair-wise Cryptographic Models for Secure Data Exchange in P2P Database Management Systems
International Association for Cryptologic Research (IACR)
Pair-wise Cryptographic Models for Secure Data Exchange in P2P Database Management Systems Sk. Md, University of Tsukuba, Tsukuba, 305-8573 Japan okamoto@risk.tsukuba.ac.jp ABSTRACT A peer-to-peer database augments a conventional database man- agement system with an inter-operability layer (i.e. map- pings
WHEN A PAIR of nuclear-powered Russian submarines was reported patrolling
California at Los Angeles, University of
WHEN A PAIR of nuclear-powered Russian submarines was reported patrolling off the eastern seaboard by the Navy to track submarines, the Times added that such tracking "can be done from aircraft, ships, underwater sensors, or other submarines." But the article failed to mention perhaps the most important part
meraculous: de novo genome assembly with short paired-end reads
Chapman, Jarrod A.; Ho, Isaac; Sunkara, Sirisha; Luo, Shujun; Schroth, Gary P.; Rokhsar, Daniel S.
2011-08-01
We describe a new algorithm, meraculous, for whole genome assembly of deep paired-end short reads, and apply it to the assembly of a dataset of paired 75-bp Illumina reads derived from the 15.4 megabase genome of the haploid yeast Pichia stipitis. More than 95% of the genome is recovered, with no errors; half the assembled sequence is in contigs longer than 101 kilobases and in scaffolds longer than 269 kilobases. Incorporating fosmid ends recovers entire chromosomes. Meraculous relies on an efficient and conservative traversal of the subgraph of the k-mer (deBruijn) graph of oligonucleotides with unique high quality extensions in the dataset, avoiding an explicit error correction step as used in other short-read assemblers. A novel memory-efficient hashing scheme is introduced. The resulting contigs are ordered and oriented using paired reads separated by ~280 bp or ~3.2 kbp, and many gaps between contigs can be closed using paired-end placements. Practical issues with the dataset are described, and prospects for assembling larger genomes are discussed.
29 Nov 2001 A. Bacchetta -Fragmentation to probe transversity 31 Hadron pair azimuthal angle
1 29 Nov 2001 A. Bacchetta - Fragmentation to probe transversity 31 Hadron pair azimuthal angle 29 Nov 2001 A. Bacchetta - Fragmentation to probe transversity 32 Center of mass angle hadron decay plane Center of mass direction in lab frame Center of mass frame R #12;2 29 Nov 2001 A. Bacchetta
Calix[4]pyrrole: A New Ion-Pair Receptor As Demonstrated by Liquid-Liquid Extraction
Wintergerst, Mr. Matthieu; Levitskaia, Tatiana G.; Moyer, Bruce A; Sessler, Jonathan L.; Delmau, Laetitia Helene
2008-01-01
Solvent extraction studies provide confirming evidence that meso-octamethylcalix[4]pyrrole acts as an ion-pair receptor for cesium chloride and cesium bromide in nitrobenzene solution. The stoichiometry of the interaction under extraction conditions from water to nitrobenzene was determined from plots of the cesium distribution ratios vs. cesium salt and receptor concentration, indicating the formation of an ion-paired 1:1:1 cesium:calix[4]pyrrole:halide complex. The extraction results were modeled to evaluate the equilibria inherent to the solvent extraction system, either with chloride or bromide. The binding energy between the halide anion and the calix[4]pyrrole was found to be about 7 kJ/mol larger for cesium chloride than for the cesium bromide. The ion-pairing free energies between the calix[4]pyrrole-halide complex and the cesium cation are nearly the same within experimental uncertainty for either halide, consistent with a structural model in which the Cs+ cation resides in the calix bowl. These results are unexpected since nitrobenzene is a very polar solvent that generally leads to dissociated complexes in the organic phase when used as a diluent in extraction studies of univalent ions. Control studies involving nitrate revealed no evidence of ion-pairing for CsNO3 under conditions identical to those where it is observed for CsCl and CsBr.
Eleven Guidelines for Implementing Pair Programming in the Classroom Laurie Williams1
McCrickard, Scott
requires specific classroom management techniques. We have created nine guidelines for successfully in the classroom. Implementing effective pair programming requires several specific classroom management techniques on the part of the teaching staff. Based upon our experiences, we previously documented classroom management
Vortex-Pair Dynamics in Anisotropic Bistable Media: A Kinematic Approach Aric Hagberg1
Meron, Ehud
Alamos, New Mexico 87545, USA 2 Department of Solar Energy and Environmental Physics, BIDR, Ben Gurion type upon rotation by =2. We study vortex-pair dynamics by deriving kinematic equations for a front with contour lines that form a closed loop. Equations of this kind, but for isotropic systems and infinite
Higher order QED in high mass e+ e- pairs production at RHIC
Anthony J. Baltz; Joakim Nystrand
2010-03-19
Lowest order and higher order QED calculations have been carried out for the RHIC high mass e+ e- pairs observed by PHENIX with single ZDC triggers. The lowest order QED results for the experimental acceptance are about two standard deviations larger than the PHENIX data. Corresponding higher order QED calculations are within one standard deviation of the data.
Research Statement Algebraic combinatorics is my research area, with the focus on Jones pairs,
Chan, Ada Sze Sze
Ada Chan 1 Research Statement Algebraic combinatorics is my research area, with the focus on Jones pairs, type II matrices and their relations to association schemes. Association schemes encode that satisfy three types of conditions cor- responding to the three Reidemeister moves on link diagrams [5
COLLISIONS OF VORTEX FILAMENT PAIRS VALERIA BANICA, ERWAN FAOU, AND EVELYNE MIOT
Faou, Erwan
COLLISIONS OF VORTEX FILAMENT PAIRS VALERIA BANICA, ERWAN FAOU, AND EVELYNE MIOT Abstract. We consider the problem of collisions of vortex filaments for a model introduced by Klein, Majda and Damodaran [KMD95] and Zakharov [Z88, Z99] to describe the interaction of almost parallel vortex filaments
Evidence for the 125 GeV Higgs boson decaying to a pair of ? leptons
Apyan, Aram
A search for a standard model Higgs boson decaying into a pair of ? leptons is performed using events recorded by the CMS experiment at the LHC in 2011 and 2012. The dataset corresponds to an integrated luminosity of 4.9 ...
Top-quark pair + 1-jet production at next-to-leading order QCD
S. Dittmaier; P. Uwer; S. Weinzierl
2008-07-08
Top-quark pair production with an additional jet is an important signal and background process at the LHC. We present the next-to-leading order QCD calculation for this process and show results for integrated as well as differential cross sections.
Disorder-induced dynamics in a pair of coupled heterogeneous phase oscillator Carlo R. Laing
Laing, Carlo R.
Disorder-induced dynamics in a pair of coupled heterogeneous phase oscillator networks Carlo R investigate the new dynamics induced by this "frozen" dis- order. We find that for sufficiently high disorder, the differential equations governing the dynam- ics of the macroscopic order parameters of the network show chaotic
Measurement of prompt J/? pair production in pp collisions at ?s = 7 Tev
Khachatryan, Vardan [Yerevan Physics Institute (Armenia)
2014-09-01
Production of prompt J/? meson pairs in proton-proton collisions at ?s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb?¹. The two J/? mesons are fully reconstructed via their decays into ?? ?? pairs. This observation provides for the first time access to the high-transverse-momentum region of J/? pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/? transverse momentum (p_{T}^{J/?}) and rapidity (|y^{J/?}|): |y^{J/?}| < 1.2 for p_{T}^{J/?} > 6.5 GeV/c, 1.2 < |y^{J/?}| < 1.43 for a p_{T} threshold that scales linearly with |y^{J/?}| from 6.5 to 4.5 GeV/c, and 1.43 < |y^{J/?}| < 2.2 for p_{T}^{J/?} > 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/? pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/? polarization imply modifications to the cross section ranging from -31% to +27%.
Bugeaud, Yann
of view: rather than giving su#cient conditions ensuring the transcendence of a given number #, we take the fact that if the sequence of partial quotients of a real irrational number # has some special#cient conditions ensuring the transcendence of a given number #, we take a pair (#, # # ) of real numbers, and we
Bose–Einstein correlations of ?^0 pairs from hadronic Z^0 decays
Wilson, Graham Wallace; OPAL Collaboration; Abbiendi, G.; Ainsley, C.; Å kesson, P.F.; Alexander, G.; Allison, J.; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; Axen, D.
2003-05-01
We observe Bose–Einstein correlations in ?^0 pairs using back-to-back two jet hadronic events from Z^0 decays in the data sample collected by the OPAL detector at LEP 1 from 1991 to 1995. Using a static Gaussian picture for the pion emitter source...
Product measurements and fully symmetric measurements in qubit-pair tomography: A numerical study
Yong Siah Teo; Huangjun Zhu; Berthold-Georg Englert
2009-07-24
State tomography on qubit pairs is routinely carried out by measuring the two qubits separately, while one expects a higher efficiency from tomography with highly symmetric joint measurements of both qubits. Our numerical study of simulated experiments does not support such expectations.
CDF Note 10436 Measurement of the Forward Backward Asymmetry in Top Pair Production in the
Quigg, Chris
CDF Note 10436 Measurement of the Forward Backward Asymmetry in Top Pair Production in the Dilepton) We report on a measurement of the inclusive forward-backward asymmetry in tÂ¯t production production at energies at the Tevatron, which has been measured to be consistent with standard model
Visual Image of Cooper Pairing in Superconductors A. O. E. Animalu
Nigeria Nsukka, Nigeria and Tepper L. Gill Department of Electrical & Computer Engineering Computational-relativistic quasiparticle energy in (k-space) of a Cooper pair, Ek = k 2 + k( ), as an eigenvalue of a 4 × 4 Hamiltonian construction of a positive energy relativistic wave equation for an integral spin particle. We find a new class
Monolithic Source of Photon Pairs Rolf Horn,1,* Payam Abolghasem,2
Monolithic Source of Photon Pairs Rolf Horn,1,* Payam Abolghasem,2 Bhavin J. Bijlani,2 Dongpeng and Astronomy, University of Waterloo, 200 University Avenue W, Waterloo, Ontario, N2L 3G1, Canada 2 The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King
Generation of paired photons in a quantum separable state in Bragg
50A, 772 07 Olomouc, Czech Republic 3Edward S. Rodgers Department of Electrical and Computer Engineering, University of Toronto, 10 King's Collage Road, Toronto, Ontario M5S3G4, Canada 4Departament photon pair sources," N. J. Phys. 12, 093027 (2010). 5. T. Aichele, A. I. Lvovsky, and S. Schiller
Measurement of prompt J/? pair production in pp collisions at ?s = 7 Tev
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, Vardan [Yerevan Physics Institute (Armenia)
2014-09-01
Production of prompt J/? meson pairs in proton-proton collisions at ?s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb?¹. The two J/? mesons are fully reconstructed via their decays into ?? ?? pairs. This observation provides for the first time access to the high-transverse-momentum region of J/? pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/? transverse momentum (pTJ/?) and rapidity (|yJ/?|): |yJ/?| TJ/? > 6.5 GeV/c, 1.2 J/?| T threshold that scales linearly with |yJ/?| from 6.5 to 4.5 GeV/c, and 1.43 J/?| TJ/? > 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/? pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/? polarization imply modifications to the cross section ranging from -31% to +27%.
Random perturbations of spiking activity in a pair of coupled neurons
Random perturbations of spiking activity in a pair of coupled neurons Boris Gutkin , J¨urgen Jost on the firing be- haviour of two coupled Type 1 or Type 2 neurons. In Hodgkin-Huxley model neurons with standard that regular spiking and fast spiking neurons in the rat somatosensory cortex exhibit Type 1 and Type 2 firing
PHYSICAL REVIEW C 85, 034328 (2012) Pairing dynamics in particle transport
Bertsch George F.
2012-01-01
PHYSICAL REVIEW C 85, 034328 (2012) Pairing dynamics in particle transport Guillaume Scamps on particle transport in time-dependent theories based on the Hartree-Fock- Bogoliubov (HFB) or BCS in particle densities. This can be ameliorated by freezing the occupation numbers during the evolution in TDHF
A Distributed Scheme for Efficient Pair-wise Comparison of Complete Genomes
Bansal, Arvind K.
#12;48 A Distributed Scheme for Efficient Pair-wise Comparison of Complete Genomes Valerian S}@mcs.kent.edu 1 Corresponding author Abstract The comparisons of newly sequenced genomes against a genome and a CORBA-based implementation to compare and align gene sequences in large complete genomes, using multiple
Drell-Yan Lepton pair production at NNLO QCD with parton showers
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Hoeche, Stefan; Li, Ye; Prestel, Stefan
2015-04-13
We present a simple approach to combine NNLO QCD calculations and parton showers, based on the UNLOPS technique. We apply the method to the computation of Drell-Yan lepton-pair production at the Large Hadron Collider. We comment on possible improvements and intrinsic uncertainties.
Analyses of humanchimpanzee orthologous gene pairs to explore evolutionary hypotheses of aging
Church, George M.
Analyses of humanchimpanzee orthologous gene pairs to explore evolutionary hypotheses of aging Joa Abstract Compared to chimpanzees (Pan troglodytes), the onset of aging appears to be delayed in the human acting on genes associated with aging in different model systems, which allowed us to explore
ENVIRONMENTAL BENZENE EXPOSURE ASSESSMENT FOR PARENT-CHILD PAIRS IN ROUEN, FRANCE
Boyer, Edmond
1 ENVIRONMENTAL BENZENE EXPOSURE ASSESSMENT FOR PARENT-CHILD PAIRS IN ROUEN, FRANCE Amin KOUNIALIa environmental benzene exposure. In this study we compared personal benzene exposure and inhalation uptake in a group of children to those of their parents. We also compared levels of urinary benzene metabolites
Peng, Ze [DOE JGI
2013-01-25
Ze Peng from DOE JGI presents "Fosmid Cre-LoxP Inverse PCR Paired-End (Fosmid CLIP-PE), a Novel Method for Constructing Fosmid Pair-End Library" at the 7th Annual Sequencing, Finishing, Analysis in the Future (SFAF) Meeting held in June, 2012 in Santa Fe, NM.
Hu, Jiangping
Impurity-induced bound states in iron-based superconductors with s-wave cos kxÂ·cos ky pairing an explicit cos kxÂ·cos ky form of the pairing sym- metry in momentum space, as long as two general conditions are small near the aforementioned spots in the FBZ. Further- more, this simple form, cos kxÂ·cos ky
Generation of macroscopic pair-correlated atomic beams by four-wave mixing in Bose, and W. Ketterle, Generation of macroscopic pair-correlated atomic beams by four-wave mixing in Bose of the elastic scattering process. When a weak input beam (third wave) was applied as a seed, it was amplified
Zhang, Yong-Tao
and the mechanism of sound generation in the interaction between an oblique shock wave and a pair of vortices. WeInteraction of an oblique shock wave with a pair of parallel vortices: Shock dynamics and mechanism of sound generation Shuhai Zhanga China Aerodynamics Research and Development Center, Mianyang, Sichuan
Is there the color-flavor locking in the instanton induced quark-antiquark pairing in QCD vacuum?
Hoang Ba Thang
2001-06-11
By means of the functional integral method we show that in the case of the quark-antiquark pairing at zero temperature and zero chemical potential (in the vacuum) the singlet pairing is more preferable than that with the color-flavor locking (CFL)
Method of Extracting Is-A and Part-Of Relations Using Pattern Pairs in Mass Corpus
Method of Extracting Is-A and Part-Of Relations Using Pattern Pairs in Mass Corpus Se-Jong Kim, yhlee95, jhlee}@postech.ac.kr Abstract. This paper proposes a method that extracts term pairs satisfying to a coreference resolution (Yang and Su, 2007). However, these methods consider only single sentences to extract
A Bayesian-based Method for Particle Track Identification in Low-energy Pair-creation Telescopes
California at Berkeley, University of
.32.147.236. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/proceedings/cpcr.jsp #12;A LOW-ENERGYA Bayesian-based Method for Particle Track Identification in Low-energy Pair-creation Telescopes optimized for energies up to 50 MeV, we describe a low-energy pair event reconstruction approach partly
Methods and composition for the production of orthogonal tRNA-aminoacyl tRNA synthetase pairs
Schultz, Peter G. (La Jolla, CA); Wang, Lei (San Diego, CA); Anderson, John Christopher (San Diego, CA); Chin, Jason W. (San Diego, CA); Liu, David R. (Lexington, MA); Magliery, Thomas J. (North Haven, CT); Meggers, Eric L. (Philadelphia, PA); Mehl, Ryan Aaron (San Diego, CA); Pastrnak, Miro (San Diego, CA); Santoro, Stephen William (San Diego, CA); Zhang, Zhiwen (San Diego, CA)
2012-05-08
This invention provides compositions and methods for generating components of protein biosynthetic machinery including orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases. Methods for identifying orthogonal pairs are also provided. These components can be used to incorporate unnatural amino acids into proteins in vivo.
John, Volker
48 2 Functional Analysis for Linear Saddle Point Problems 2.4 Examples of Pairs of Finite Element Spaces Violating the Discrete Inf-Sup Condition Remark 2.50. On simple pairs of finite element spaces. The simplest and most common finite element spaces are spaces of continuous functions which are piecewise
California at Berkeley, University of
Generation region of pulsating aurora obtained simultaneously by the FAST satellite and a Syowa-Iceland), with reference to simultaneous data obtained by a Syowa-Iceland conjugate pair of observatories. The aurora simultaneously by the FAST satellite and a Syowa-Iceland conjugate pair of observatories, J. Geophys. Res., 109
Two-dimensional model problem to explain counter-rotating vortex pair formation in a transverse jet
Mahesh, Krishnan
Two-dimensional model problem to explain counter-rotating vortex pair formation in a transverse jet A two-dimensional model problem is used to study the evolution of the cross section of a transverse jet and the counter-rotating vortex pair CVP . The solution to the model problem shows deformation of the jet similar
Gentry, Cale M; Wade, Mark W; Stevens, Martin J; Dyer, Shellee D; Zeng, Xiaoge; Pavanello, Fabio; Gerrits, Thomas; Nam, Sae Woo; Mirin, Richard P; Popovi?, Miloš A
2015-01-01
Correlated photon pairs are a fundamental building block of quantum photonic systems. While pair sources have previously been integrated on silicon chips built using customized photonics manufacturing processes, these often take advantage of only a small fraction of the established techniques for microelectronics fabrication and have yet to be integrated in a process which also supports electronics. Here we report the first demonstration of quantum-correlated photon pair generation in a device fabricated in an unmodified advanced (sub-100nm) complementary metal-oxide-semiconductor (CMOS) process, alongside millions of working transistors. The microring resonator photon pair source is formed in the transistor layer structure, with the resonator core formed by the silicon layer typically used for the transistor body. With ultra-low continuous-wave on-chip pump powers ranging from 5 $\\mu$W to 400 $\\mu$W, we demonstrate pair generation rates between 165 Hz and 332 kHz using >80% efficient WSi superconducting nano...
Ying Zhang; Masayuki Matsuo; Jie Meng
2010-12-17
The neutron pair correlation in nuclei near the neutron drip-line is investigated using the selfconsistent continuum Skyrme-Hartree-Fock-Bogoliubov theory formulated with the coordinate-space Green's function technique. Numerical analysis is performed for even-even N = 86 isotones in the Mo-Sn region, where the 3p3/2 and 3p1/2 orbits lying near the Fermi energy are either weakly bound or unbound. The quasiparticle states originating from the l = 1 orbits form resonances with large widths, which are due to the low barrier height and the strong continuum coupling caused by the pair potential. Analyzing in detail the pairing properties and roles of the quasiparticle resonances, we found that the l = 1 broad quasiparticle resonances persist to feel the pair potential and contribute to the pair correlation even when their widths are comparable with the resonance energy.
Search for the standard model Higgs boson in tau lepton pair final states
D0 Collaboration
2012-05-16
We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with zero, one, or two or more jets using data corresponding to an integrated luminosity of up to 7.3 fb^{-1} collected with the D0 detector at the Fermilab Tevatron collider. The analysis is sensitive to Higgs boson production via gluon gluon fusion, associated vector boson production, and vector boson fusion, and to Higgs boson decays to tau lepton pairs or W boson pairs. Observed (expected) limits are set on the ratio of 95% C.L. upper limits on the cross section times branching ratio, relative to those predicted by the Standard Model, of 14 (22) at a Higgs boson mass of 115 GeV and 7.7 (6.8) at 165 GeV.
Finding the first cosmic explosions. III. Pulsational pair-instability supernovae
Whalen, Daniel J.; Smidt, Joseph [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Even, Wesley; Fryer, Chris L. [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Woosley, S. E. [Department of Astronomy and Astrophysics, UCSC, Santa Cruz, CA 95064 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Clayton, Victoria 3800 (Australia); Stiavelli, Massimo [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
2014-02-01
Population III supernovae have been the focus of growing attention because of their potential to directly probe the properties of the first stars, particularly the most energetic events that can be seen at the edge of the observable universe. But until now pulsational pair-instability supernovae, in which explosive thermonuclear burning in massive stars fails to unbind them but can eject their outer layers into space, have been overlooked as cosmic beacons at the earliest redshifts. These shells can later collide and, like Type IIn supernovae, produce superluminous events in the UV at high redshifts that could be detected in the near infrared today. We present numerical simulations of a 110 M {sub ?} pulsational pair-instability explosion done with the Los Alamos radiation hydrodynamics code Radiation Adaptive Grid Eulerian. We find that collisions between consecutive pulsations are visible in the near infrared out to z ? 15-20 and can probe the earliest stellar populations at cosmic dawn.
Electromagnetic Heavy Lepton Pair Production in Relativistic Heavy-Ion Collisions
Sengul, M Y; Mercan, O; Karakus, N G
2015-01-01
We calculate the cross sections of electromagnetic productions of muon and tauon pair productions from the ultra-relativistic heavy ion collisions. Since the Compton wavelengths of muon and tauon are comparable to the radius of the colliding ions, nuclear form factors play important roles for calculating the cross sections. Recent measurement [1] indicates that the neutrons are differently distributed from the protons therefore this affects the cross section of the heavy lepton pair production. In order to see the effects of the neutron distributions in the nucleus, we used analytical expression of the Fourier transforms of the Wood-Saxon distribution. Cross section calculations show that Wood-Saxon distribution function is more sensitive to the parameter R compare to the parameter a.
Optimising the signal-to-noise ratio in measurement of photon pairs with detector arrays
Eric Lantz; Paul-Antoine Moreau; Fabrice Devaux
2014-11-24
To evidence multimode spatial entanglement of spontaneous down-conversion, detector arrays allow a full field measurement, without any a priori selection of the paired photons. We show by comparing results of the recent literature that electron-multiplying CCD (EMCCD) cameras allow, in the present state of technology, the detection of quantum correlations with the best signal-to-noise ratio (SNR), while intensified CCD (ICCD) cameras allow at best to identify pairs. The SNR appears to be proportional to the square root of the number of coherence cells in each image, or Schmidt number. Then, corrected estimates are derived for extended coherence cells and not very low and not space-stationary photon fluxes. Finally, experimental measurements of the SNR confirm our model.
Testing the local-void alternative to dark energy using galaxy pairs
Wang, F Y
2013-01-01
The possibility that we live in a special place in the universe, close to the center of a large, radially inhomogeneous void, has attracted attention recently as an alternative to dark energy or modified gravity to explain the accelerating universe. We show that the distribution of orientations of galaxy pairs can be used to test the Copernican principle that we are not in a central or special region of Universe. The popular void models can not fit both the latest type Ia supernova, cosmic microwave background data and the distribution of orientations of galaxy pairs simultaneously. Our results rule out the void models at the $4\\sigma$ confidence level as the origin of cosmic acceleration and favor the Copernican principle.
Superfluid phases of triplet pairing and rapid cooling of the neutron star in Cassiopeia A
Lev B. Leinson
2014-12-16
In a simple model it is demonstrated that the neutron star surface temperature evolution is sensitive to the phase state of the triplet superfluid condensate. A multicomponent triplet pairing of superfluid neutrons in the core of a neutron star with participation of several magnetic quantum numbers leads to neutrino energy losses exceeding the losses from the unicomponent pairing. A phase transition of the neutron condensate into the multicomponent state triggers more rapid cooling of superfluid core in neutron stars. This makes it possible to simulate an anomalously rapid cooling of neutron stars within the minimal cooling paradigm without employing any exotic scenarios suggested earlier for rapid cooling of isolated neutron star in Cassiopeia A.
Superfluid phases of triplet pairing and rapid cooling of the neutron star in Cassiopeia A
Leinson, Lev B
2015-01-01
In a simple model it is demonstrated that the neutron star surface temperature evolution is sensitive to the phase state of the triplet superfluid condensate. A multicomponent triplet pairing of superfluid neutrons in the core of a neutron star with participation of several magnetic quantum numbers leads to neutrino energy losses exceeding the losses from the unicomponent pairing. A phase transition of the neutron condensate into the multicomponent state triggers more rapid cooling of superfluid core in neutron stars. This makes it possible to simulate an anomalously rapid cooling of neutron stars within the minimal cooling paradigm without employing any exotic scenarios suggested earlier for rapid cooling of isolated neutron star in Cassiopeia A.
First Measurement of the Fraction of Top Quark Pair Production Through Gluon-Gluon Fusion
CDF Collaboration; T. Aaltonen
2008-04-08
We present the first measurement of the fraction of top quark pair production through gluon-gluon fusion. We use 0.96/fb of s**(1/2)=1.96 TeV p-pbar collision data recorded with the CDF II detector at Fermilab. We identify the candidate t-tbar events with a high-energy charged lepton, a neutrino candidate, and four or more jets. Using charged particles with low transverse momentum in t-tbar events, we find the fraction of top quark pair production through gluon-gluon fusion to be 0.07+/-0.14(stat)+/-0.07(syst), corresponding to a 95% confidence level upper limit of 0.33, in agreement with the standard model NLO prediction of 0.15+/-0.05.
On detection of narrow angle e+e- pairs from dark photon decays
A. V. Dermenev; S. V. Donskov; S. N. Gninenko; S. B. Kuleshov; V. A. Matveev; V. V. Myalkovskiy; V. D. Peshekhonov; V. A. Poliakov; A. A. Savenkov; V. O. Tikhomirov; I. A. Zhukov
2015-03-19
A class of models of dark sectors consider new very weak interaction between the ordinary and dark matter transmitted by U'(1) gauge bosons A' (dark photons) mixing with our photons. If such A's exist, they could be searched for in a light-shining-through-a-wall experiment with a high energy electron beam from the CERN SPS. The proposed search scheme suggests detection of the e+e- pairs produced in the A' -> e+e- decay with a very small opening angle. Coordinate chambers based on the thin-wall drift tubes with a minimal material budget and a two-hit resolution for e+ and e- tracks separated by more than 0.5 mm are considered as an option for detecting such pairs.
NNLL threshold resummation for top-pair and single-top production
Nikolaos Kidonakis
2012-12-17
I discuss threshold resummation at NNLL accuracy in the standard moment-space approach in perturbative QCD for top-pair and single-top production. For top quark pair production I present new approximate NNLO results for the total cross section and for the top quark transverse momentum and rapidity distributions at 8 TeV LHC energy. I discuss the accuracy of the soft-gluon approximation and show that the NLO and NNLO approximate results from resummation are practically indistinguishable from exact NLO and partial NNLO results. For single top production I present new approximate NNLO results for the total cross sections in all three channels at the LHC and also for the top quark transverse momentum distributions in t-channel production and in top-quark associated production with a W boson. For both ttbar and single-top production the agreement of theoretical results with LHC and Tevatron data is excellent.
Can pair-instability supernova models match the observations of superluminous supernovae?
Kozyreva, Alexandra
2015-01-01
An increasing number of so-called superluminous supernovae (SLSNe) are discovered. It is believed that at least some of them with slowly fading light curves originate in stellar explosions induced by the pair instability mechanism. Recent stellar evolution models naturally predict pair instability supernovae (PISNe) from very massive stars at wide range of metallicities (up to Z=0.006, Yusof et al. 2013). In the scope of this study we analyse whether PISN models can match the observational properties of SLSNe with various light curve shapes. Specifically, we explore the influence of different degrees of macroscopic chemical mixing in PISN explosive products on the resulting observational properties. We artificially apply mixing to the 250 Msun PISN evolutionary model from Kozyreva et al. (2014) and explore its supernova evolution with the one-dimensional radiation hydrodynamics code STELLA. The greatest success in matching SLSN observations is achieved in the case of an extreme macroscopic mixing, where all r...
CW-pumped telecom band polarization entangled photon pair generation in a Sagnac interferometer
Li, Yan; Ding, Dong-Sheng; Shi, Bao-Sen
2015-01-01
A polarization entangled photon pair source is widely used in many quantum information processing applications such as teleportation, quantum swapping, quantum computation and high precision quantum metrology. Here, we report on the generation of a continuous-wave pumped degenerated 1550 nm polarization entangled photon pair source at telecom wavelength using a type-II phase-matched periodically poled KTiOPO4 crystal in a Sagnac interferometer. Hong-Ou-Mandel-type interference measurement shows the photon bandwidth of 2.4 nm. High quality of entanglement is verified by various kinds of measurements, for example two-photon interference fringes, Bell inequality and quantum states tomography. The wavelength of photons can be tuned over a broad range by changing the temperature of crystal or pump power without losing the quality of entanglement. This source will be useful for building up long-distance quantum networks.
Power-efficient production of photon pairs in a tapered chalcogenide microwire
Evan Meyer-Scott; Audrey Dot; Raja Ahmad; Lizhu Li; Martin Rochette; Thomas Jennewein
2015-02-25
Using tapered fibers of As2Se3 chalcogenide glass, we produce photon pairs at telecommunication wavelengths with low pump powers. We found maximum coincidences-to-accidentals ratios of $2.13\\pm0.07$ for degenerate pumping with 3.2 {\\mu}W average power, and $1.33\\pm0.03$ for non-degenerate pumping with 1.0 {\\mu}W and 1.5 {\\mu}W average power of the two pumps. Our results show that the ultrahigh nonlinearity in these microwires could allow single-photon pumping to produce photon pairs, enabling the production of large entangled states, heralding of single photons after lossy transmission, and photonic quantum information processing with nonlinear optics.
Spatial correlation of photon pairs produced in spontaneous parametric down-conversion
Procopio, L. M. [Departamento de Fisica, Cinvestav, A.P. 14-740, Mexico D.F. 07000 (Mexico); Rosas-Ortiz, O. [Departamento de Fisica, Cinvestav, A.P. 14-740, Mexico D.F. 07000 (Mexico); Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, Mexico D.F. 01000 (Mexico); Velazquez, V. [Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, A.P. 20-364, Mexico D.F. 04510 (Mexico)
2010-10-11
We report the observation of spatial biphoton correlation in spontaneous parametric down conversion. The optical bench includes a type-I BBO crystal of effective length 2 mm, pumped by a 100 mW violet laser diode centered at 405.38 nm. Photon pairs are created with degenerate wavelength {approx_equal}810.76 nm. Once the horizontal counting rates have been measured, a simple geometrical recipe is shown to be useful in calculating bounds for the width of vertical counting rates. The spatial correlation between idler and signal photons is illustrated with a coincidence distribution of the coordinate pair (x{sub s},x{sub i}), with x{sub i,s} the idler (signal) detector position in horizontal scan.
Outgoing electromagnetic power induced from pair plasma falling into a rotating black hole
Kojima, Yasufumi
2015-01-01
We examine energy conversion from accreting pair plasma to outgoing Poynting flux by black hole rotation. Our approach is based on a two-fluid model consisting of collisionless pair plasma. The electric potential is not constant along magnetic field lines, unlike an ideal magnetohydrodynamics approximation. We show how and where longitudinal electric fields and toroidal magnetic fields are generated by the rotation, whereas they vanish everywhere for radial flow in a split monopole magnetic field in a Schwarzschild black hole. Outgoing electromagnetic power in a steady state is calculated by applying the WKB method to the perturbation equations for a small spin parameter. In our model, the luminosity has a peak in the vicinity of the black hole, but is damped toward the event horizon and infinity. The power at the peak is of the same order as that in the Blandford--Znajek process, although the physical mechanism is different.
Flavor Pairing in Medieval European Cuisine: A Study in Cooking with Dirty Data
Varshney, Kush R; Wang, Jun; Myers, Daniel
2013-01-01
An important part of cooking with computers is using statistical methods to create new, flavorful ingredient combinations. The flavor pairing hypothesis states that culinary ingredients with common chemical flavor components combine well to produce pleasant dishes. It has been recently shown that this design principle is a basis for modern Western cuisine and is reversed for Asian cuisine. Such data-driven analysis compares the chemistry of ingredients to ingredient sets found in recipes. However, analytics-based generation of novel flavor profiles can only be as good as the underlying chemical and recipe data. Incomplete, inaccurate, and irrelevant data may degrade flavor pairing inferences. Chemical data on flavor compounds is incomplete due to the nature of the experiments that must be conducted to obtain it. Recipe data may have issues due to text parsing errors, imprecision in textual descriptions of ingredients, and the fact that the same ingredient may be known by different names in different recipes. ...
Masood, W.; Rizvi, H.
2011-04-15
Nonlinear electrostatic shock waves are studied in unmagnetized, dissipative pair-ion plasmas. The dissipation in the system is taken into account by considering the effect of kinematic viscosity of both positive and negative ions in plasmas. The system of fluid equations for asymmetric pair-ion plasma is reduced to Korteweg-deVries-Burgers equation in the limit of small amplitude perturbation. It is observed that the system under consideration admits rarefactive shocks. Keeping in view the practical applications, the nonlinear propagation of both the exploding and imploding shocks is investigated and the differences are expounded in detail. The present study may have relevance in the study of the formation of electrostatic shocks in laser-induced implosion devices, star formation, supernovae explosion, etc.
Maeda, Kiminori [Department of Chemistry, University of Oxford, Centre for Advanced Electron Spin Resonance, Inorganic Chemistry Laboratory, Oxford (United Kingdom)] [Department of Chemistry, University of Oxford, Centre for Advanced Electron Spin Resonance, Inorganic Chemistry Laboratory, Oxford (United Kingdom); Liddell, Paul; Gust, Devens [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, 85287-1604 (United States)] [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, 85287-1604 (United States); Hore, P. J. [Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, Oxford (United Kingdom)] [Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, Oxford (United Kingdom)
2013-12-21
Spin-selective reactions of radical pairs are conventionally modelled using an approach that dates back to the 1970s [R. Haberkorn, Mol. Phys. 32, 1491 (1976)]. An alternative approach based on the theory of quantum measurements has recently been suggested [J. A. Jones and P. J. Hore, Chem. Phys. Lett. 488, 90 (2010)]. We present here the first experimental attempt to discriminate between the two models. Pulsed electron paramagnetic resonance spectroscopy has been used to investigate intramolecular electron transfer in the radical pair form of a carotenoid-porphyrin-fullerene molecular triad. The rate of spin-spin relaxation of the fullerene radical in the triad was found to be inconsistent with the quantum measurement description of the spin-selective kinetics, and in accord with the conventional model when combined with spin-dephasing caused by rotational modulation of the anisotropic g-tensor of the fullerene radical.
HIGHER PICARD VARIETIES AND THE HEIGHT PAIRING KLAUS KU"NNEMANN
defined under suitable assumptions height pai* *rings (1) XK: CHp(XK )0Q x CHd+1-p of the Hodge index theorem should hold for the pairing (1). We denote by Ap(XK )Q the subgroup of CHp(XK )0Q of this note is to show that these theorems hold for the subquotients Bp(AK )Q of CHp(AK )0Q . The hard
Relativistic Quantization of Cooper Pairs and Distributed Electrons in Rotating Superconductors
I. E. Bulyzhenkov
2009-07-02
Relativistic time synchronization along closed integral lines maintains magnetic flux quantization independently from gravitation. All Fermi-volume electrons form time-averaged electromagnetic fields within rotating conductors, while Fermi-surface superelectrons enable flux quantization in SQUID experiments. Inertia is not related to instantaneous self-coherent states of the distributed electric charge and, therefore, the Cooper pair mass can not be measured in principle from magnetic flux quantization.
Thomas Garrity
2012-05-25
A new classification scheme for pairs of real numbers is given, generalizing earlier work of the author that used continued fraction, which in turn was motivated by ideas from statistical mechanics in general and work of Knauf and Fiala and Kleban in particular. Critical for this classification are the number theoretic and geometric properties of the triangle map, a type of multi-dimensional continued fraction.
Next-to-leading order QCD corrections to slepton pair production via vector-boson fusion
Partha Konar; Dieter Zeppenfeld
2006-12-11
Slepton pairs can be produced in vector-boson fusion processes at hadron colliders. The next-to-leading order QCD corrections to the electroweak production cross section for p p -> slepton+ slepton- +2jets at order alpha_s alpha^4 have been calculated and implemented in a NLO parton-level Monte Carlo program. Numerical results are presented for the CERN Large Hadron Collider.
Two pairs of interacting EBs towards the LMC in the OGLE database
Aviv Ofir
2008-12-17
A single point source on the OGLE LMC database shows the characteristics of two superimposed eclipsing binaries (EBs). The two EBs happen to have periods very close to the 3:2 resonance. The telescope's small PSF and the apparent resonance between the two EBs raises the suspicion that this is not chance alignment but rather a compact hierarchical system of two pairs of interacting EBs in 3:2 resonance.
Fast vacuum decay into particle pairs in strong electric and magnetic fields
Yoshimasa Hidaka; Takumi Iritani; Hideo Suganuma
2011-02-01
We discuss fermion pair productions in strong electric and magnetic fields. We point out that, in the case of massless fermions, the vacuum persistency probability per unit time and volume is zero in the strong electric and magnetic fields, while it is finite when the magnetic field is absent. The contribution from the lowest Landau level (LLL) dominates this phenomenon. We also discuss dynamics of the vacuum decay, using an effective theory of the LLL projection, taking into account the back reaction.
Contributions of different neutron pairs in different approaches for neutrinoless double beta decay
Alberto Escuderos; Amand Faessler; Vadim Rodin; Fedor Simkovic
2010-06-07
The methods used till now to calculate the neutrinoless double beta decay matrix elements are: the Quasiparticle Random Phase Approximation (QRPA), the Shell Model (SM), the angular momentum projected Hartee-Fock-Bogoliubov approach (HFB) and the Interacting Boson Model (IBM). The different approaches are compared specifically concerning the the angular momenta and parities of the neutron pairs, which are changed into two protons by the $0\
A proposal for testing subcritical vacuum pair production with high power lasers
Gregori, G; Rajeev, P P; Chen, H; Clarke, R J; Huffman, T; Murphy, C D; Prozorkevich, A V; Roberts, C D; Röpke, G; Schmidt, S M; Smolyansky, S A; Wilks, S; Bingham, R; 10.1016/j.hedp.2009.11.001
2010-01-01
We present a proposal for testing the prediction of non-equilibrium quantum field theory below the Schwinger limit. The proposed experiments should be able to detect a measurable number of gamma rays resulting from the annihilation of pairs in the focal spot of two opposing high intensity laser beams. We discuss the dependence of the expected number of gamma rays with the laser parameters and compare with the estimated background level of gamma hits for realistic laser conditions.
Two-color ghost interference with photon pairs generated in hot atoms
Ding Dongsheng; Zhou Zhiyuan; Shi Baosen; Zou Xubo; Guo Guangcan [Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026 (China)
2012-09-15
We report on an experimental observation of a two-photon ghost interference experiment. A distinguishing feature of our experiment is that the photons are generated via a non-degenerated spontaneous four-wave mixing process in a hot atomic ensemble; therefore the photon has narrow bandwidth. Besides, there is a large difference in frequency between two photons in a pair. Our works may be important to achieve more secure, large transmission capacity long-distance quantum communication.
X-shooter Science Verification Proposal A special co-moving white dwarfmain sequence pair
Liske, Jochen
and HD 122750 form a co-moving proper motion pair (PM in mas/yr: RA, Dec, from UCAC-2): WD 1401-147 (-170: The white dwarf (WD) WD 1401-147 and the main sequence (MS) star HD 122750 form a co-moving proper motion laboratory to study the complex physics of pulsating WDs in a quantitative manner. Scientific Case: WD 1401-147
Top quark pair production measurements using the ATLAS detector at the LHC
Trincaz-Duvoid, Sophie; The ATLAS collaboration
2015-01-01
Inclusive and differential cross sections of top quark pair production at have been measured with the ATLAS detector at the LHC at ?s = 7 TeV and ?s = 8 TeV. Inclusive measurements are in good agreement with Standard Model predictions. Differential cross section measurements are compared to different sets of generators, parton showering and hadronization simulations, PDF and calculations. This provides constraints to improve the MC modeling.
Mirror, Mirror: The Pairing of Hal Carter and Alan Seymour in Picnic
Williams, Philip M.
2010-04-23
Content-Type text/plain; charset=UTF-8 1 Mirror, Mirror The Pairing of Hal Carter and Alan Seymour in Picnic Presented by Philip Middleton Williams, Ph.D. The William Inge Theatre Festival Scholars’ Conference... the drama. William Inge provides us with the classic example of these two contrasting characters in Picnic with the friendship of Hal Carter and Alan Seymour. These young men could not be more opposite in terms of character and physique; Inge describes...
The avoidance of a previously neutral stimulus paired with frustrative nonreward
Beard, William Washington
1975-01-01
involved pairing of a CS (light) with frustra- tive nonreward in Goal Box 1. During Phase III, Ss were tested in a separate hurdle-jump apparatus to de- monstrate avoidance of the now aversive CS by jumping at the sound of a buzzer. It was found... Ss conditioned to the CS jumped the hurdle significantly faster than any of the other subgroups. However, an analysis of the frequency of avoidance re- sponses revealed no statistically significant differ- ences between all subgroups...
Direct generation of photon triplets using cascaded photon-pair sources
H. Hübel; D. R. Hamel; A. Fedrizzi; S. Ramelow; K. J. Resch; T. Jennewein
2010-07-28
Non-classical states of light, such as entangled photon pairs and number states, are essential for fundamental tests of quantum mechanics and optical quantum technologies. The most widespread technique for creating these quantum resources is the spontaneous parametric down-conversion (SPDC) of laser light into photon pairs. Conservation of energy and momentum in this process, known as phase-matching, gives rise to strong correlations which are used to produce two-photon entanglement in various degrees of freedom. It has been a longstanding goal of the quantum optics community to realise a source that can produce analogous correlations in photon triplets, but of the many approaches considered, none have been technically feasible. In this paper we report the observation of photon triplets generated by cascaded down-conversion. Here each triplet originates from a single pump photon, and therefore quantum correlations will extend over all three photons in a way not achievable with independently created photon pairs. We expect our photon-triplet source to open up new avenues of quantum optics and become an important tool in quantum technologies. Our source will allow experimental interrogation of novel quantum correlations, the post-selection free generation of tripartite entanglement without post- selection and the generation of heralded entangled-photon pairs suitable for linear optical quantum computing. Two of the triplet photons have a wavelength matched for optimal transmission in optical fibres, ideally suited for three-party quantum communication. Furthermore, our results open interesting regimes of non-linear optics, as we observe spontaneous down-conversion pumped by single photons, an interaction also highly relevant to optical quantum computing.
A proposal for testing subcritical vacuum pair production with high power lasers
G. Gregori; D. B. Blaschke; P. P. Rajeev; H. Chen; R. J. Clarke; T. Huffman; C. D. Murphy; A. V. Prozorkevich; C. D. Roberts; G. Röpke; S. M. Schmidt; S. A. Smolyansky; S. Wilks; R. Bingham
2010-05-18
We present a proposal for testing the prediction of non-equilibrium quantum field theory below the Schwinger limit. The proposed experiments should be able to detect a measurable number of gamma rays resulting from the annihilation of pairs in the focal spot of two opposing high intensity laser beams. We discuss the dependence of the expected number of gamma rays with the laser parameters and compare with the estimated background level of gamma hits for realistic laser conditions.
The Merger Rate to Redshift One from Kinematic Pairs: Caltech Faint Galaxy Redshift Survey XI
R. G. Carlberg; Judith G. Cohen; D. R. Patton; Roger Blandford; David W. Hogg; H. K. C. Yee; S. L. Morris; H. Lin; Lennox L. Cowie; Esther Hu; Antoinette Songaila
2000-02-01
The rate of mass accumulation due to galaxy merging depends on the mass, density, and velocity distribution of galaxies in the near neighborhood of a host galaxy. The fractional luminosity in kinematic pairs combines all of these effects in a single estimator which is relatively insensitive to population evolution. Here we use a k-corrected and evolution compensated volume-limited sample drawing about 300 redshifts from CFGRS and 3000 from CNOC2 to measure the rate and redshift evolution of merging. We identify kinematic pairs with projected separations less than either 50 or 100 \\hkpc and rest-frame velocity differences of less than 1000\\kms. The fractional luminosity in pairs is modeled as f_L(Delta v,r_p,M_r^{ke})(1+z)^{m_L} where [f_L,m_L] are [0.14+/-0.07,0+/-1.4] and [0.37+/-0.7,0.1+/-0.5] for r_p= 0.2 M*) is 0.02+/-0.01(1+z)^{0.1+/-0.5} M*~Gyr^{-1}. Present day high-luminosity galaxies therefore have accreted approximately 0.15M* of their mass over the approximately 7 Gyr to redshift one. (abridged)
Spatial properties of entangled photon pairs generated in nonlinear layered structures
Jan Perina Jr
2011-11-07
A spatial quantum model of spontaneous parametric down-conversion in nonlinear layered structures is developed expanding the interacting vectorial fields into monochromatic plane waves. A two-photon spectral amplitude depending on the signal- and idler-field frequencies and propagation directions is used to derive transverse profiles of the emitted fields as well as their spatial correlations. Intensity spatial profiles and their spatial correlations are mainly determined by the positions of transmission peaks formed in these structures with photonic bands. A method for geometry optimization of the structures with respect to efficiency of the nonlinear process is suggested. Several structures composed of GaN/AlN layers are analyzed as typical examples. They allow the generation of photon pairs correlated in several emission directions. Photon-pair generation rates increasing better than the second power of the number of layers can be reached. Also structures efficiently generated photon pairs showing anti-bunching and anti-coalescence can be obtained. Three reasons for splitting the correlated area in photonic-band-gap structures are revealed: zig-zag movement of photons inside the structure, spatial symmetry and polarization-dependent properties. Also spectral splitting can be observed in these structures.
B-DNA structure is intrinsically polymorphic: even at the level of base pair positions
Maehigashi, Tatsuya; Hsiao, Chiaolong; Woods, Kristen Kruger; Moulaei, Tinoush; Hud, Nicholas V.; Williams, Loren Dean
2012-10-23
Increasingly exact measurement of single crystal X-ray diffraction data offers detailed characterization of DNA conformation, hydration and electrostatics. However, instead of providing a more clear and unambiguous image of DNA, highly accurate diffraction data reveal polymorphism of the DNA atomic positions and conformation and hydration. Here we describe an accurate X-ray structure of B-DNA, painstakingly fit to a multistate model that contains multiple competing positions of most of the backbone and of entire base pairs. Two of ten base-pairs of CCAGGCCTGG are in multiple states distinguished primarily by differences in slide. Similarly, all the surrounding ions are seen to fractionally occupy discrete competing and overlapping sites. And finally, the vast majority of water molecules show strong evidence of multiple competing sites. Conventional resolution appears to give a false sense of homogeneity in conformation and interactions of DNA. In addition, conventional resolution yields an average structure that is not accurate, in that it is different from any of the multiple discrete structures observed at high resolution. Because base pair positional heterogeneity has not always been incorporated into model-building, even some high and ultrahigh-resolution structures of DNA do not indicate the full extent of conformational polymorphism.
Pair dispersion in a chaotic flow reveals the role of the memory of initial velocity
Eldad Afik; Victor Steinberg
2015-02-10
The leading paradigm for chaotic flows dominated by dissipation predicts an exponential growth of the mean distance between pairs of fluid elements, in the long run. This is reflected in the analysis of experimental results on tracer particles and the discussions which follow, as reported in recent experimental and numerical publications. To quantitatively validate this prediction, we have conducted a microfluidic experiment generating elastic turbulence, a flow characterised in the literature as smooth in space and random in time. To our great surprise, we discovered that the pair separation follows a much slower power-law --- also known as ballistic --- a notion overlooked so far for flows of this type. We provide conclusive experimental evidence that this scaling is well-desribed by the same coefficients derived from the short-time dynamics. Our finding reinforces the role of the ballistic regime over a significant range in time and space, providing a quantitative estimation for the spreading of particles in mixing microfluidic flows based on the initial velocity snapshot. Finally we note that the conditions for the asymptotic exponential pair separation are quite stringent when it comes to tracer particles and are unlikely to be realised in wall-bounded flows. Therefore this work raises questions regarding the relevance and applicability of the currently leading paradigm.
Calix[4]pyrrole: A New Ion-Pair Receptor As Demonstrated by Liquid-Liquid Extraction
Wintergerst, Mr. Matthieu; Levitskaia, Tatiana G.; Moyer, Bruce A; Sessler, Jonathan L.; Delmau, Laetitia Helene
2008-01-01
Solvent-extraction studies provide confirming evidence that meso-octamethylcalix[4]pyrrole acts as an ion-pair receptor for cesium chloride and cesium bromide in nitrobenzene solution. The stoichiometry of the interaction under extraction conditions from water to nitrobenzene was determined from plots of the cesium distribution ratios vs cesium salt and receptor concentration, indicating the formation of an ionpaired 1:1:1 cesium:calix[4]pyrrole:halide complex. The extraction results were modeled to evaluate the equilibria inherent to the solvent-extraction system, with either chloride or bromide. The binding energy between the halide anion and the calix[4]pyrrole was found to be about 7 kJ/mol larger for cesium chloride than for the cesium bromide. The ion-pairing free energies between the calix[4]pyrrole-halide complex and the cesium cation are nearly the same within experimental uncertainty for either halide, consistent with a structural model in which the Cs+ cation resides in the calix bowl. These results are unexpected since nitrobenzene is a polar solvent that generally leads to dissociated complexes in the organic phase when used as a diluent in extraction studies of univalent ions. Control studies involving nitrate revealed no evidence of ion pairing for CsNO3 under conditions identical to those where it is observed for CsCl and CsBr.
Neutrino pair emission due to scattering of electrons off fluxoids in superfluid neutron star cores
A. D. Kaminker; D. G. Yakovlev; P. Haensel
1997-02-18
We study the emission of neutrinos, resulting from the scattering of electrons off magnetic flux tubes (fluxoids) in the neutron star cores with superfluid (superconducting) protons. In the absence of proton superfluidity (T> T_{cp}), this process transforms into the well known electron synchrotron emission of neutrino pairs in a locally uniform magnetic field B, with the neutrino energy loss rate Q proportional to B^2 T^5. For temperatures T not much below T_{cp}, the synchrotron regime (Q \\propto T^5) persists and the emissivity Q can be amplified by several orders of magnitude due to the appearance of the fluxoids and associated enhancement of the field within them. For lower T, the synchrotron regime transforms into the bremsstrahlung regime (Q \\propto T^6) similar to the ordinary neutrino-pair bremsstrahlung of electrons which scatter off atomic nuclei. We calculate Q numerically and represent our results through a suitable analytic fit. In addition, we estimate the emissivities of two other neutrino-production mechanisms which are usually neglected -- neutrino-pair bremsstrahlung processes due to electron-proton and electron-electron collisions. We show that the electron-fluxoid and electron-electron scattering can provide the main neutrino production mechanisms in the neutron star cores with highly superfluid protons and neutrons at T scattering is significant if the initial, locally uniform magnetic field B > 10^{13} G.
STUDYING INTERCLUSTER GALAXY FILAMENTS THROUGH STACKING gmBCG GALAXY CLUSTER PAIRS
Zhang Yuanyuan; Dietrich, Joerg P.; McKay, Timothy A.; Nguyen, Alex T. Q.; Sheldon, Erin S.
2013-08-20
We present a method to study the photometric properties of galaxies in filaments by stacking the galaxy populations between pairs of galaxy clusters. Using Sloan Digital Sky Survey data, this method can detect the intercluster filament galaxy overdensity with a significance of {approx}5{sigma} out to z = 0.40. Using this approach, we study the g - r color and luminosity distribution of filament galaxies as a function of redshift. Consistent with expectation, filament galaxies are bimodal in their color distribution and contain a larger blue galaxy population than clusters. Filament galaxies are also generally fainter than cluster galaxies. More interestingly, the observed filament population seems to show redshift evolution at 0.12 < z < 0.40: the blue galaxy fraction has a trend to increase at higher redshift; such evolution is parallel to the ''Butcher-Oemler effect'' of galaxy clusters. We test the dependence of the observed filament density on the richness of the cluster pair: richer clusters are connected by higher density filaments. We also test the spatial dependence of filament galaxy overdensity: this quantity decreases when moving away from the intercluster axis between a cluster pair. This method provides an economical way to probe the photometric properties of filament galaxies and should prove useful for upcoming projects like the Dark Energy Survey.
Top quark pair properties using the ATLAS detector at the LHC
Barone, Gaetano; The ATLAS collaboration
2015-01-01
Top quark pair properties using the ATLAS detector at the LHC The latest measurements of the properties of the top quark using the ATLAS experiment are presented. The top quark mass is one of the fundamental parameters of the Standard Model. A measurement based on a multidimensional template fit that can constrain the uncertainties on the energy measurements of jets is presented and combined with a measurement using dilepton events. In addition, novel measurements aiming to measure the mass in a welldefined scheme are presented. The top quark pair charge asymmetry is an asymmetry predicted to occur beyond leadingorder QCD in the Standard Model, and may be significantly enhanced by the presence of new physics. The ttbar production charge asymmetry is measured inclusively and differentially using the 7 and 8 TeV ATLAS datasets. Making use of the large number of top quark pairs collected, we also present measurements of the spin correlation between top and antitop quarks and discuss their sensitivities t...
Pair Production of Heavy Quarkonium and $B_c(^*)$ Mesons at Hadron Colliders
Rong Li; Yu-Jie Zhang; Kuang-Ta Chao
2009-03-12
We investigate the pair production of S-wave heavy quarkonium at the LHC in the color-singlet mechanism (CSM) and estimate the contribution from the gluon fragmentation process in the color-octet mechanism (COM) for comparison. With the matrix elements extracted previously in the leading order calculations, the numerical results show that the production rates are quite large for the pair production processes at the LHC. The $p_t$ distribution of double $J/\\psi$ production in the CSM is dominant over that in the COM when $p_t$ is smaller than about 8GeV. For the production of double $\\Upsilon$, the contribution of the COM is always larger than that in the CSM. The large differences in the theoretical predictions between the CSM and COM for the $p_t$ distributions in the large $p_t$ region are useful in clarifying the effects of COM on the quarkonium production. We also investigate the pair production of S-wave $B_c$ and $B_c^*$ mesons, and the measurement of these processes is useful to test the CSM and extract the LDMEs for the $B_c$ and $B_c^*$ mesons.
Overstable librations can account for the paucity of mean motion resonances among exoplanet pairs
Goldreich, Peter; Schlichting, Hilke E. E-mail: hilke@mit.edu
2014-02-01
We assess the multi-planet systems discovered by the Kepler satellite in terms of current ideas about orbital migration and eccentricity damping due to planet-disk interactions. Our primary focus is on first order mean motion resonances, which we investigate analytically to lowest order in eccentricity. Only a few percent of planet pairs are in close proximity to a resonance. However, predicted migration rates (parameterized by ?{sub n}=n/| n-dot |) imply that during convergent migration most planets would have been captured into first order resonances. Eccentricity damping (parameterized by ?{sub e}=e/| e-dot |) offers a plausible resolution. Estimates suggest ? {sub e}/? {sub n} ? (h/a){sup 2} ? 10{sup –2}, where h/a is the ratio of disk thickness to radius. Together, eccentricity damping and orbital migration give rise to an equilibrium eccentricity, e {sub eq} ? (? {sub e}/? {sub n}){sup 1/2}. Capture is permanent provided e {sub eq} ? ?{sup 1/3}, where ? denotes the planet to star mass ratio. But for e {sub eq} ? ?{sup 1/3}, capture is only temporary because librations around equilibrium are overstable and lead to passage through resonance on timescale ? {sub e}. Most Kepler planet pairs have e {sub eq} > ?{sup 1/3}. Since ? {sub n} >> ? {sub e} is the timescale for migration between neighboring resonances, only a modest percentage of pairs end up trapped in resonances after the disk disappears. Thus the paucity of resonances among Kepler pairs should not be taken as evidence for in situ planet formation or the disruptive effects of disk turbulence. Planet pairs close to a mean motion resonance typically exhibit period ratios 1%-2% larger than those for exact resonance. The direction of this shift undoubtedly reflects the same asymmetry that requires convergent migration for resonance capture. Permanent resonance capture at these separations from exact resonance would demand ?(? {sub n}/? {sub e}){sup 1/2} ? 0.01, a value that estimates of ? from transit data and (? {sub e}/? {sub n}){sup 1/2} from theory are insufficient to match. Plausible alternatives involve eccentricity damping during or after disk dispersal. The overstability referred to above has applications beyond those considered in this investigation. It was discovered numerically by Meyer and Wisdom in their study of the tidal evolution of Saturn's satellites.
Khachatryan, V.
A search is performed for long-lived massive neutral particles decaying to quark-antiquark pairs. The experimental signature is a distinctive topology of a pair of jets, originating at a secondary vertex. Events were ...
Constraints on the Higgs boson width from off-shell production and decay to Z-boson pairs
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, Vardan; et al.,
2014-09-01
Constraints are presented on the total width of the recently discovered Higgs boson, Gamma[H], using its relative on-shell and off-shell production and decay rates to a pair of Z bosons, where one Z boson decays to an electron or muon pair, and the other to an electron, muon, or neutrino pair. The analysis is based on the data collected by the CMS experiment at the LHC in 2011 and 2012, corresponding to integrated luminosities of 5.1 inverse femtobarns at a centre-of-mass energy sqrt(s) = 7 TeV and 19.7 inverse femtobarns at sqrt(s) = 8 TeV. A simultaneous maximum likelihood fitmore »to the measured kinematic distributions near the resonance peak and above the Z-boson pair production threshold leads to an upper limit on the Higgs boson width of Gamma[H] « less
Popovych, Roman
]). Terwilliger showed [5, 10] that a Leonard pair X, Y satisfies a certain algebraic relations with respect to commutators. In turn, the Terwilliger relations follow from to the so-called relations of the AW
Unhavaithaya, Yingdee
Meiotic chromosome segregation involves pairing and segregation of homologous chromosomes in the first division and segregation of sister chromatids in the second division. Although it is known that the centromere and ...
Gordon, Sarah Elisabeth; Gordon, Sarah Elisabeth
2012-01-01
all students? names on a popsicle stick and have studentsthe big T-P-S cards ? popsicle sticks with each student?seach pair, but using the popsicle sticks to call on a few.
NOETHERIAN BANACH JORDAN PAIRS N. Boudi*, A. Fern'andez L'opezy, E. Garc'ia
by Benslimane and Boudi [BeB1] to the alternative case. For a Jordan algebra J or a Jordan pair V a* *nd Boudi [BeB2] proved that a complex Noetherian Banach Jordan algebra is finite dimensional
Lu, Jianxu
2008-10-10
Variational method is used to investigate, at zero temperature, the deformed- Fermi-surfaces mechanism for solving the problem of superconducting pairing of two species of fermions (i.e., spin-up and -down) of mismatched ...
Gomez-Ceballos, Guillelmo
We measure the inclusive forward–backward asymmetry of the charged-lepton pseudorapidities from top-quark pairs produced in proton–antiproton collisions and decaying to final states that contain two charged leptons (electrons ...
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Mani, Tomoyasu [Brookhaven National Lab. (BNL), Upton, NY (United States); Grills, David C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Miller, John R. [Brookhaven National Lab. (BNL), Upton, NY (United States)
2015-01-28
A recently-developed instrument for time-resolved infrared detection following pulse radiolysis has been used to measure the ?(C?N) IR band of the radical anion of a CN-substituted fluorene in tetrahydrofuran. Specific vibrational frequencies can exhibit distinct frequency shifts due to ion-pairing, which can be explained in the framework of the vibrational Stark effect. Measurements of the ratio of free ions and ion-pairs in different electrolyte concentrations allowed us to obtain an association constant and free energy change for ion-pairing. This new method has the potential to probe the geometry of ion-pairing and allows the reduction potentials of molecules to be determined in the absence of electrolyte in an environment of low dielectric constant.
Vacuum Potentials for the Two Only Permanent Free Particles, Proton and Electron. Pair Productions
J. X. Zheng-Johansson
2015-02-26
The two only species of isolatable, smallest, or unit charges +e and -e present in nature interact with the universal vacuum in a polarisable dielectric representation through two uniquely defined vacuum potential functions. All of the non-composite subatomic particles containing one-unit charges, +e or -e, are therefore formed in terms of the IED model of the respective charges, of zero rest masses, oscillating in either of the two unique vacuum potential fields, together with the radiation waves of their own charges. In this paper we give a first principles treatment of the dynamics of charge in a dielectric vacuum, based on which, combined with solutions for the radiation waves obtained previously, we subsequently derive the vacuum potential function for a given charge q, which we show to be quadratic and consist each of quantised potential levels, giving therefore rise to quantised characteristic oscillation frequencies of the charge and accordingly quantised, sharply-defined masses of the IED particles. By further combining with relevant experimental properties as input information, we determine the IED particles built from the charges +e,-e at their first excited states in the respective vacuum potential wells to be the proton and the electron, the observationally two only stable (permanently lived) and "free" particles containing one-unit charges. Their antiparticles as produced in pair productions can be accordingly determined. The characteristics of all of the other more energetic non-composite subatomic particles can also be recognised. We finally discuss the energy condition for pair production, which requires two successive energy supplies to (1) first disintegrate the bound pair of vaculeon charges +e,-e composing a vacuuon of the vacuum and (2) impart masses to the disintegrated charges.
Aggelen, Helen van; Department of Chemistry, Duke University, Durham, North Carolina 27708 ; Yang, Yang; Yang, Weitao
2014-05-14
Despite their unmatched success for many applications, commonly used local, semi-local, and hybrid density functionals still face challenges when it comes to describing long-range interactions, static correlation, and electron delocalization. Density functionals of both the occupied and virtual orbitals are able to address these problems. The particle-hole (ph-) Random Phase Approximation (RPA), a functional of occupied and virtual orbitals, has recently known a revival within the density functional theory community. Following up on an idea introduced in our recent communication [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013)], we formulate more general adiabatic connections for the correlation energy in terms of pairing matrix fluctuations described by the particle-particle (pp-) propagator. With numerical examples of the pp-RPA, the lowest-order approximation to the pp-propagator, we illustrate the potential of density functional approximations based on pairing matrix fluctuations. The pp-RPA is size-extensive, self-interaction free, fully anti-symmetric, describes the strong static correlation limit in H{sub 2}, and eliminates delocalization errors in H{sub 2}{sup +} and other single-bond systems. It gives surprisingly good non-bonded interaction energies – competitive with the ph-RPA – with the correct R{sup ?6} asymptotic decay as a function of the separation R, which we argue is mainly attributable to its correct second-order energy term. While the pp-RPA tends to underestimate absolute correlation energies, it gives good relative energies: much better atomization energies than the ph-RPA, as it has no tendency to underbind, and reaction energies of similar quality. The adiabatic connection in terms of pairing matrix fluctuation paves the way for promising new density functional approximations.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Abazov, Victor Mukhamedovich
2011-10-11
We present a search for the pair production of first generation scalar leptoquarks (LQ) in data corresponding to an integrated luminosity of 5.4 fb-1 collected with the D0 detector at the Fermilab Tevatron Collider in pp? collisions at ?s = 1.96 TeV. In the channel LQLQ ? eq?eq?, where q,q? are u or d quarks, no significant excess of data over background is observed, and we set a 95% C.L. lower limit of 326 GeV on the leptoquark mass, assuming equal probabilities of leptoquark decays to eq and ?eq?.
Linear response calculation using the canonical-basis TDHFB with a schematic pairing functional
Shuichiro Ebata; Takashi Nakatsukasa; Kazuhiro Yabana
2010-09-17
A canonical-basis formulation of the time-dependent Hartree-Fock-Bogoliubov (TDHFB) theory is obtained with an approximation that the pair potential is assumed to be diagonal in the time-dependent canonical basis. The canonical-basis formulation significantly reduces the computational cost. We apply the method to linear-response calculations for even-even nuclei. E1 strength distributions for proton-rich Mg isotopes are systematically calculated. The calculation suggests strong Landau damping of giant dipole resonance for drip-line nuclei.
S. Frixione; E. Laenen; P. Motylinski; B. R. Webber
2007-02-20
We explain how angular correlations in leptonic decays of vector bosons and top quarks can be included in Monte Carlo parton showers, in particular those matched to NLO QCD computations. We consider the production of $n$ pairs of leptons, originating from the decays of $n$ electroweak vector bosons or of $n$ top quarks, in the narrow-width approximation. In the latter case, the information on the $n$ $b$ quarks emerging from the decays is also retained. We give results of implementing this procedure in MC@NLO
A. Moujahid; A. D'Anjou; F. J. Torrealdea; C. Sarasola
2012-04-17
Many biological processes involve synchronization between nonequivalent systems, i.e, systems where the difference is limited to a rather small parameter mismatch. The maintenance of the synchronized regime in this cases is energetically costly \\cite{1}. This work studies the energy implications of synchronization phenomena in a pair of structurally flexible coupled neurons that interact through electrical coupling. We show that the forced synchronization between two nonidentical neurons creates appropriate conditions for an efficient actuation of adaptive laws able to make the neurons structurally approach their behaviours in order to decrease the flow of energy required to maintain the synchronization regime.
Self-regulation of the reconnecting current layer in relativistic pair plasma reconnection
S. Zenitani; M. Hesse
2008-08-07
We investigate properties of the reconnecting current layer in relativistic pair plasma reconnection. We found that the current layer self-regulates its thickness when the current layer runs out current carriers, and so relativistic reconnection retains a fast reconnection rate. Constructing a steady state Sweet-Parker model, we discuss conditions for the current sheet expansion. Based on the energy argument, we conclude that the incompressible assumption is invalid in relativistic Sweet-Parker reconnection. The guide field cases are more incompressible than the anti-parallel cases, and we find a more significant current sheet expansion.
A transmission matrix for a fused pair of integrable defects in the sine-Gordon model
E. Corrigan; C. Zambon
2010-06-04
Within the quantum sine-Gordon model a transmission matrix describing the scattering of a soliton with a fused pair of integrable defects is proposed. The result is consistent with the classical picture of scattering and highlights the differences between two defects located at separated points and two defects fused at the same point. Moreover, the analysis reveals how, for certain choices of parameters, both the soliton-soliton and the lightest-breather-soliton S-matrices of the sine-Gordon model are embedded within the transmission matrix, supporting an interpretation in which defects may be regarded as soliton constituents.
SUSY QCD Corrections to Higgs Pair Production from Bottom Quark Fusion
Sally Dawson; Chung Kao; Yili Wang
2007-10-23
We present a complete next-to-leading order (NLO) calculation for the total cross section for inclusive Higgs pair production via bottom-quark fusion at the CERN Large Hadron Collider (LHC) in the minimal supersymmetric standard model (MSSM) and the minimal supergravity model (mSUGRA). We emphasize the contributions of squark and gluino loops (SQCD) and the decoupling properties of our results for heavy squark and gluino masses. The enhanced couplings of the b quark to the Higgs bosons in supersymmetric models with large tanb yield large NLO SQCD corrections in some regions of parameter space.
A monolithic polarization-independent frequency-filter system for filtering of photon pairs
Ahlrichs, Andreas; Berkemeier, Christoph; Sprenger, Benjamin; Benson, Oliver [Institute of Physics, Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin (Germany)] [Institute of Physics, Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin (Germany)
2013-12-09
We set up a long-term stable filtering system that consists of cascaded monolithic Fabry-Pérot filters to enhance the suppression and free spectral range. An effective free spectral range of hundreds of GHz allows the system to be used as a high resolution monochromator, with a linewidth of 192 MHz. As an important application a single mode is filtered from photon pairs generated by a parametric down-conversion source, and their indistinguishability is proven by measuring the Hong-Ou-Mandel effect with a visibility of 96%. We report that undesired birefringence, which is often encountered with monolithic cavities, can be avoided by stress-free mounting.
Dynamical view of pair creation in uniform electric and magnetic fields
Naoto Tanji
2009-05-12
Pair creation in a uniform classical electromagnetic field (Schwinger mechanism) is studied focusing on the time evolution of the distribution of created particles. The time evolution of the distribution in time-dependent fields is also presented as well as effects of back reaction. Motivated by the Glasma flux tube, which may be formed at the initial stage of heavy-ion collisions, we investigate effects of a magnetic field parallel to an electric field, and find that the magnetic field makes the evolution of a fermion system faster.
Biexciton emission from single isoelectronic traps formed by nitrogen-nitrogen pairs in GaAs
Takamiya, Kengo; Fukushima, Toshiyuki; Yagi, Shuhei; Hijikata, Yasuto; Yaguchi, Hiroyuki [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku , Saitama 338-8570 (Japan); Mochizuki, Toshimitsu; Yoshita, Masahiro; Akiyama, Hidefumi [Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Kuboya, Shigeyuki; Onabe, Kentaro [Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Katayama, Ryuji [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)
2013-12-04
We have studied photoluminescence (PL) from individual isoelectronic traps formed by nitrogen-nitrogen (NN) pairs in GaAs. Sharp emission lines due to exciton and biexciton were observed from individual isoelectronic traps in nitrogen atomic-layer doped (ALD) GaAs. The binding energy of biexciton bound to individual isoelectronic traps was approximately 8 meV. Both the exciton and biexciton luminescence lines show completely random polarization and no fine-structure splitting. These results are desirable to the application to the quantum cryptography used in the field of quantum information technology.
Static quark anti-quark pair in SU(2) gauge theory
A. Bazavov; P. Petreczky; A. Velytsky
2008-09-11
We study singlet and triplet correlation functions of static quark anti-quark pair defined through gauge invariant time-like Wilson loops and Polyakov loop correlators in finite temperature SU(2) gauge theory. We use the Luescher-Weisz multilevel algorithm, which allows to calculate these correlators at very low temperatures. We observe that the naive separation of singlet and triplet states in general does not hold non-perturbatively, however, is recovered in the limit of small separation and the temperature dependence of the corresponding correlators is indeed very different.
Static Electron-Positron Pair Creation in Strong Fields for a Nonlinear Dirac model
Julien Sabin
2011-12-12
We consider the Hartree-Fock approximation of Quantum Electrodynamics, with the exchange term neglected. We prove that the probability of static electron-positron pair creation for the Dirac vacuum polarized by an external field of strength $Z$ behaves as $1-\\exp(-\\kappa Z^{2/3})$ for $Z$ large enough. Our method involves two steps. First we estimate the vacuum expectation of general quasi-free states in terms of their total number of particles, which can be of general interest. Then we study the asymptotics of the Hartree-Fock energy when $Z\\to+\\infty$ which gives the expected bounds.
Pairing effects on the collectivity of quadrupole states around 32Mg
M. Yamagami; Nguyen Van Giai
2003-07-11
The first 2+ states in N=20 isotones including neutron-rich nuclei 32Mg and 30Ne are studied by the Hartree-Fock-Bogoliubov plus quasiparticle random phase approximation method based on the Green's function approach. The residual interaction between the quasiparticles is consistently derived from the hamiltonian density of Skyrme interactions with explicit velocity dependence. The B(E2) transition probabilities and the excitation energies of the first 2+ states are well described within a single framework. We conclude that pairing effects account largely for the anomalously large B(E2) value and the very low excitation energy in 32Mg.
Fermion Pair Production From an Electric Field Varying in Two Dimensions
J. E. Seger; A. B. Balantekin
1995-06-26
The Hamiltonian describing fermion pair production from an arbitrarily time-varying electric field in two dimensions is studied using a group-theoretic approach. We show that this Hamiltonian can be encompassed by two, commuting SU(2) algebras, and that the two-dimensional problem can therefore be reduced to two one-dimensional problems. We compare the group structure for the two-dimensional problem with that previously derived for the one-dimensional problem, and verify that the Schwinger result is obtained under the appropriate conditions.
Reduced effect of impurities on the universal pairing scale in the cuprates
Vorontsov, A. B.; Abanov, Artem; Vavilov, M. G.; Chubukov, A. V.
2010-01-01
? and ??a, when the pairing problem involves incoherent fermions and near- gapless dynamical bosons and is very different from the d-wave version of the BCS theory. We find that in this situ- ation the ratio ?cr /T 0? is about four times larger than 0... in Ap? ? differs from p? ? because of damping induced by scattering off thermal bosons. In par- ticular, even for a gap with a perfect cos px?cos py form a maximum in Ap? =0? is still present in some neighborhood of a node ?a Fermi arc...
Formation of Cooper pairs in quantum oscillations of electrons in plasma
Dvornikov, Maxim
2009-01-01
We study low energy quantum oscillations of electron gas in plasma. It is shown that two electrons participating in these oscillations acquire additional negative energy when they interact by means of a virtual plasmon. The additional energy leads to the formation a Cooper pair and possible existence of the superconducting phase in the system. We suggest that this mechanism supports slowly damping oscillations of electrons without any energy supply. Basing on our model we put forward the hypothesis the superconductivity can occur in a low energy ball lightning.
Evidence for spin selectivity of triplet pairs in superconducting spin valves
Banerjee, N.; Smiet, C. B.; Smits, R. G. J.; Ozaeta, A.; Bergeret, F. S.; Blamire, M. G.; Robinson, J. W. A.
2014-01-09
Evidence for spin-selectivity of triplet pairs in superconducting spin-valves N. Banerjee1, C. B. Smiet1, R. G. J. Smits1, A. Ozaeta2, F. S. Bergeret2, M. G. Blamire1, J. W. A. Robinson1* 1Department of Materials Science and Metallurgy, University... . Pang, B. S. H., Bell, C., Tomov, R. I., Durrell, J. H., & Blamire, M. G. Pseudo spin-valve behavior in oxide ferromagnet/superconductor/ferromagnet trilayers. Phys. Lett. A 341, 313–319 (2005). 35. Kalcheim, Y., Kirzhner, T., Koren, G. & Millo, O...
Adams, J.; Aggarwal, MM; Ahammed, Z.; Amonett, J.; Anderson, BD; Arkhipkin, D.; Averichev, GS; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, LS; Baudot, J.; Bekele, S.; Belaga, VV; Bellwied, R.; Berger, J.; Bezverkhny, BI; Bharadwaj, S.; Bhatia, VS; Bichsel, H.; Billmeier, A.; Bland, LC; Blyth, CO; Bonner, BE; Botje, M.; Boucham, A.; Brandin, A.; Bravar, A.; Bystersky, M.; Cadman, RV; Cai, XZ; Caines, H.; Sanchez, MCD; Carroll, J.; Castillo, J.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopdhyay, S.; Chen, HF; Chen, Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, JP; Cormier, TM; Cramer, JG; Crawford, HJ; Das, D.; Das, S.; de Moura, MM; Derevschikov, AA; Didenko, L.; Dietel, T.; Dong, WJ; Dong, X.; Draper, JE; Du, F.; Dubey, AK; Dunin, VB; Dunlop, JC; Mazumdar, MRD; Eckardt, V.; Edwards, WR; Efimov, LG; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Faivre, J.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Foley, KJ; Fomenko, K.; Fu, J.; Gagliardi, Carl A.; Gans, J.; Ganti, MS; Gaudichet, L.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, JE; Grachov, O.; Grebenyuk, O.; Grosnick, D.; Guertin, SM; Guo, Y.; Gupta, A.; Gutierrez, TD; Hallman, TJ; Hamed, A.; Hardtke, D.; Harris, JW; Heinz, M.; Henry, TW; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, GW; Huang, HZ; Huang, SL; Hughes, EW; Humanic, TJ; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, WW; Janik, M.; Jiang, H.; Jones, PG; Judd, EG; Kabana, S.; Kang, K.; Kaplan, M.; Keane, D.; Khodyrev, VY; Kiryluk, J.; Kisiel, A.; Kislov, EM; Klay, J.; Klein, SR; Klyachko, A.; Koetke, DD; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kramer, M.; Kravtsov, P.; Kravtsov, VI; Krueger, K.; Kuhn, C.; Kulikov, AI; Kumar, A.; Kunz, CL; Kutuev, RK; Kuznetsov, AA; Lamont, MAC; Landgraf, JM; Lange, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lehocka, S.; LeVine, MJ; Li, C.; Li, Q.; Li, Y.; Lindenbaum, SJ; Lisa, MA; Liu, F.; Liu, L.; Liu, QJ; Liu, Z.; Ljubicic, T.; Llope, WJ; Long, H.; Longacre, RS; Lopez-Noriega, M.; Love, WA; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, GL; Ma, JG; Ma, YG; Magestro, D.; Mahajan, S.; Mahapatra, DP; Majka, R.; Mangotra, LK; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Marx, JN; Matis, HS; Matulenko, YA; McClain, CJ; McShane, TS; Meissner, F.; Melnick, Y.; Meschanin, A.; Miller, ML; Milosevich, Z.; Minaev, NG; Mironov, C.; Mischke, A.; Mishra, D.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, CF; Mora-Corral, MJ; Morozov, DA; Morozov, V.; Munhoz, MG; Nandi, BK; Nayak, TK; Nelson, JM; Netrakanti, PK; Nikitin, VA; Nogach, LV; Norman, B.; Nurushev, SB; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Pal, SK; Panebratsev, Y.; Panitkin, SY; Pavlinov, AI; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Petrov, VA; Phatak, SC; Picha, R.; Planinic, M.; Pluta, J.; Porile, N.; Porter, J.; Poskanzer, AM; Potekhin, M.; Potrebenikova, E.; Potukuchi, BVKS; Prindle, D.; Pruneau, C.; Putschke, J.; Rai, G.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ravel, O.; Ray, RL; Razin, SV; Reichhold, D.; Reid, JG; Renault, G.; Retiere, F.; Ridiger, A.; Ritter, HG; Roberts, JB; Rogachevskiy, OV; Romero, JL; Rose, A.; Roy, C.; Ruan, L.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Savin, I.; Sazhin, PS; Schambach, J.; Scharenberg, RP; Schmitz, N.; Schroeder, LS; Schweda, K.; Seger, J.; Seyboth, P.; Shahaliev, E.; Shao, M.; Shao, W.; Sharma, M.; Shen, WQ; Shestermanov, KE; Shimanskiy, SS; Simon, F.; Singaraju, RN; Skoro, G.; Smirnov, N.; Snellings, R.; Sood, G.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, TDS; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Suaide, AAP; Sugarbaker, E.; Suire, C.; Sumbera, M.; Surrow, B.; Symons, TJM; de Toledo, AS; Szarwas, P.; Tai, A.; Takahashi, J.; Tang, AH; Tarnowsky, T.; Thein, D.; Thomas, JH; Timoshenko, S.; Tokarev, M.; Trainor, TA; Trentalange, S.; Tribble, Robert E.; Tsai, O.; Ulery, J.; Ullrich, T.; Underwood, DG; Urkinbaev, A.; Buren, GV; van Leeuwen, M.; Vander Molen, AM; Varma, R.; Vasilevski, IM; Vasiliev, AN; Vernet, R.; Vigdor, SE; Viyogi, VP; Vokal, S.; Voloshin, SA; Vznuzdaev, M.; Waggoner, B.; Wang, F.; Wang, G.; Wang, G.; Wang, XL; Wang, Y.; Wang, Y.; Wang, ZM; Ward, H.; Watson, JW; Webb, JC; Wells, R.; Westfall, GD; Wetzler, A.; Whitten, C.; Wieman, H.; Wissink, SW; Witt, R.; Wood, J.; Wu, J.; Xu, N.; Xu, Z.; Xu, ZZ; Yamamoto, E.; Yepes, P.; Yurevich, VI; Zanevsky, YV; Zhang, H.; Zhang, WM; Zhang, ZP; Zolnierczuk, PA; Zoulkarneev, R.; Zoulkarneeva, Y.; Zubarev, AN; STAR Collaboration.
2004-01-01
of e+e? pairs accompanied by nuclear dissociation in ultraperipheral heavy-ion collisions J. Adams,2 M. M. Aggarwal,28 Z. Ahammed,42 J. Amonett,19 B. D. Anderson,19 D. Arkhipkin,12 G. S. Averichev,11 Y. Bai,26 J. Balewski,16 O. Barannikova,31 L. S.... Barnby,2 J. Baudot,17 S. Bekele,27 V. V. Belaga,11 R. Bellwied,45 J. Berger,13 B. I. Bezverkhny,47 S. Bharadwaj,32 V. S. Bhatia,28 H. Bichsel,44 A. Billmeier,45 L. C. Bland,3 C. O. Blyth,2 B. E. Bonner,33 M. Botje,26 A. Boucham,37 A. Brandin,24 A...
First measurement of the forward-backward charge asymmetry in top quark pair production
D0 Collaboration; V. M. Abazov
2007-12-05
We present the first measurement of the integrated forward-backward charge asymmetry in top-antitop quark pair (ttbar) production in proton-antiproton collisions in the lepton plus jets final state. Using a b-jet tagging algorithm and kinematic reconstruction assuming ttbar+X production and decay, a sample of 0.9fb-1 of data, collected by the D0 experiment at the Fermilab Tevatron Collider, is used to measure the asymmetry for different jet multiplicities. The result is also used to set upper limits on ttbar+X production via a Z' resonance.
Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides
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Cale M. Gentry; Jeffrey M. Shainline; Mark T. Wade; Martin J. Stevens; Shellee D. Dyer; Xiaoge Zeng; Fabio Pavanello; Thomas Gerrits; Sae Woo Nam; Richard P. Mirin; Miloš A. Popovi?
2015-07-24
Correlated photon pairs are a fundamental building block of quantum photonic systems. While pair sources have previously been integrated on silicon chips built using customized photonics manufacturing processes, these often take advantage of only a small fraction of the established techniques for microelectronics fabrication and have yet to be integrated in a process which also supports electronics. Here we report the first demonstration of quantum-correlated photon pair generation in a device fabricated in an unmodified advanced (sub-100nm) complementary metal-oxide-semiconductor (CMOS) process, alongside millions of working transistors. The microring resonator photon pair source is formed in the transistor layer structure, with the resonator core formed by the silicon layer typically used for the transistor body. With ultra-low continuous-wave on-chip pump powers ranging from 5 $\\mu$W to 400 $\\mu$W, we demonstrate pair generation rates between 165 Hz and 332 kHz using >80% efficient WSi superconducting nanowire single photon detectors. Coincidences-to-accidentals ratios consistently exceeding 40 were measured with a maximum of 55. In the process of characterizing this source we also accurately predict pair generation rates from the results of classical four-wave mixing measurements. This proof-of-principle device demonstrates the potential of commercial CMOS microelectronics as an advanced quantum photonics platform with capability of large volume, pristine process control, and where state-of-the-art high-speed digital circuits could interact with quantum photonic circuits.
Non-resonant kaon pair production and medium effects in proton-nucleus collisions
E. Ya. Paryev; M. Hartmann; Yu. T. Kiselev
2015-05-08
We study the non-resonant (non-$\\phi$) production of $K^+K^-$ pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets within the collision model, based on the nuclear spectral function, for incoherent primary proton--nucleon and secondary pion--nucleon creation processes. The model takes into account the initial proton and final kaon absorption, target nucleon binding and Fermi motion as well as nuclear mean-field potential effects on these processes. We calculate the antikaon momentum dependences of the exclusive absolute and relative $K^+K^-$ pair yields in the acceptance window of the ANKE magnetic spectrometer, used in a recent experiment performed at COSY, within the different scenarios for the antikaon-nucleus optical potential. We demonstrate that the above observables are strongly sensitive to this potential. Therefore, they can be useful to help determine the $K^-$ optical potential from the direct comparison of the results of our calculations with the data from the respective ANKE-at-COSY experiment. We also show that the pion--nucleon production channels dominate in the low-momentum $K^-$, $K^+$ production in the considered kinematics and, hence, they have to be accounted for in the analysis of these data.
Non-resonant kaon pair production and medium effects in proton-nucleus collisions
Paryev, E Ya; Kiselev, Yu T
2015-01-01
We study the non-resonant (non-$\\phi$) production of $K^+K^-$ pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets within the collision model, based on the nuclear spectral function, for incoherent primary proton--nucleon and secondary pion--nucleon creation processes. The model takes into account the initial proton and final kaon absorption, target nucleon binding and Fermi motion as well as nuclear mean-field potential effects on these processes. We calculate the antikaon momentum dependences of the exclusive absolute and relative $K^+K^-$ pair yields in the acceptance window of the ANKE magnetic spectrometer, used in a recent experiment performed at COSY, within the different scenarios for the antikaon-nucleus optical potential. We demonstrate that the above observables are strongly sensitive to this potential. Therefore, they can be useful to help determine the $K^-$ optical potential from the direct comparison of the results of our calculations with the data from the respective ANKE-a...
Interstellar Hydroxyl Masers in the Galaxy. II. Zeeman Pairs and the Galactic Magnetic Field
Vincent L. Fish; Mark J. Reid; Alice L. Argon; Karl M. Menten
2003-07-08
We have identified and classified Zeeman pairs in the survey by Argon, Reid, & Menten of massive star-forming regions with 18 cm (2 Pi 3/2, J = 3/2) OH maser emission. We have found a total of more than 100 Zeeman pairs in more than 50 massive star-forming regions. The magnetic field deduced from the Zeeman splitting has allowed us to assign an overall line-of-sight magnetic field direction to many of the massive star-forming regions. Combining these data with other data sets obtained from OH Zeeman splitting, we have looked for correlations of magnetic field directions between star-forming regions scattered throughout the Galaxy. Our data do not support a uniform, Galactic-scale field direction, nor do we find any strong evidence of magnetic field correlations within spiral arms. However, our data suggest that in the Solar neighborhood the magnetic field outside the Solar circle is oriented clockwise as viewed from the North Galactic Pole, while inside the Solar circle it is oriented counterclockwise. This pattern, including the magnetic field reversal near the Sun, is in agreement with results obtained from pulsar rotation measures.
Christopher R. Iacovella; Reginald R. Rogers; Sharon C. Glotzer; Michael J. Solomon
2010-10-27
A method for measuring the pair interaction potential between colloidal particles by extrapolation measurement of collective structure to infinite dilution is presented and explored using simulation and experiment. The method is particularly well suited to systems in which the colloid is fluorescent and refractive index matched with the solvent. The method involves characterizing the potential of mean force between colloidal particles in suspension by measurement of the radial distribution function using 3D direct visualization. The potentials of mean force are extrapolated to infinite dilution to yield an estimate of the pair interaction potential, $U(r)$. We use Monte Carlo (MC) simulation to test and establish our methodology as well as to explore the effects of polydispersity on the accuracy. We use poly-12-hydroxystearic acid-stabilized poly(methyl methacrylate) (PHSA-PMMA) particles dispersed in the solvent dioctyl phthalate (DOP) to test the method and assess its accuracy for three different repulsive systems for which the range has been manipulated by addition of electrolyte.
Electroweak Measurements in Electron-Positron Collisions at W-Boson-Pair Energies at LEP
Schael, S; Bruneliere, R; Buskulic, D; De Bonis, I; Decamp, D; Ghez, P; Goy, C; Jezequel, S; Lees, J P; Lucotte, A; Martin, F; Merle, E; Minard, M N; Nief, J Y; Odier, P; Pietrzyk, B; Trocme, B; Bravo, S; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Fernandez, E; Fernandez-Bosman, M; Garrido, Ll; Grauges, E; Juste, A; Martinez, M; Merino, G; Miquel, R; Mir, Ll. M; Orteu, S; Pacheco, A; Park, I C; Perlas, J; Riu, I; Ruiz, H; Sanchez, F; Colaleo, A; Creanza, D; De Filippis, N; De Palma, M; Iaselli, G; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Bazarko, A; Becker, U; Boix, G; Bird, F; Blucher, E; Bonvicini, B; Bright-Thomas, P; Barklow, T; Buchmuller, O; Cattaneo, M; Cerutti, F; Ciulli, V; Clerbaux, B; Drevermann, H; Forty, R W; Frank, M; Greening, T C; Hagelberg, R; Halley, A W; Gianotti, F; Girone, M; Hansen, J B; Harvey, J; Jacobsen, R; Hutchcroft, D E; Janot, P; Jost, B; Knobloch, J; Kado, M; Lehraus, I; Lazeyras, P; Maley, P; Mato, P; May, J; Moutoussi, A; Pepe-Altarelli, M; Ranjard, F; Rolandi, L; Schlatter, D; Schmitt, B; Schneider, O; Tejessy, W; Teubert, F; Tomalin, I R; Tournefier, E; Veenhof, R; Valassi, A; Wiedenmann, W; Wright, A E; Ajaltouni, Z; Badaud, F; Chazelle, G; Deschamps, O; Dessagne, S; Falvard, A; Ferdi, C; Fayolle, D; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Pascolo, J M; Perret, P; Podlyski, F; Bertelsen, H; Fernley, T; Hansen, J D; Hansen, J R; Hansen, P H; Kraan, A C; Lindahl, A; Mollerud, R; Nilsson, B S; Rensch, B; Waananen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, E; Siotis, I; Vayaki, A; Zachariadou, K; Blondel, A; Bonneaud, G; Brient, J C; Machefert, F; Rouge, A; Rumpf, M; Swynghedauw, M; Tanaka, R; Verderi, M; Videau, H; Ciulli, V; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C; Antonelli, A; Antonelli, M; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Cerutti, F; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, G P; Passalacqua, L; Picchi, P; Colrain, P; Have, I. ten; Hughes, I S; Kennedy, J; Knowles, I G; Lynch, J G; Morton, W T; Negus, P; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Thompson, A S; Turnbull, R M; Wasserbaech, S; Buchmuller, O; Cavanaugh, R; Dhamotharan, S; Geweniger, C; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Stenzel, H; Tittel, K; Werner, W; Wunsch, M; Beuselinck, R; Binnie, D M; Cameron, W; Davies, G; Dornan, P J; Goodsir, S; Marinelli, N; Martin, E B; Nash, J; Nowell, J; Rutherford, S A; Sedgbeer, J K; Thompson, J C; White, R; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bouhova-Thacker, E; Bowdery, C K; Buck, P G; Clarke, D P; Ellis, G; Finch, A J; Foster, F; Hughes, G; Jones, R.W L; Keemer, N R; Pearson, M R; Robertson, N A; Sloan, T; Smizanska, M; Snow, S W; Williams, M I; van der Aa, O; Delaere, C; Leibenguth, G; Lemaitre, V; Bauerdick, L.A T; Blumenschein, U; van Gemmeren, P; Giehl, I; Holldorfer, F; Jakobs, K; Kasemann, M; Kayser, F; Kleinknecht, K; Muller, A S; Quast, G; Renk, B; Rohne, E; Sander, H G; Schmeling, S; Wachsmuth, H; Wanke, R; Zeitnitz, C; Ziegler, T; Aubert, J J; Benchouk, C; Bonissent, A; Carr, J; Coyle, P; Curtil, C; Ealet, A; Etienne, F; Fouchez, D; Motsch, F; Payre, P; Rousseau, D; Tilquin, A; Talby, M; Thulasidas, M; Aleppo, M; Antonelli, M; Ragusa, F; Buscher, V; David, A; Dietl, H; Ganis, G; Huttmann, K; Lutjens, G; Mannert, C; Manner, W; Moser, H G; Settles, R; Seywerd, H; Stenzel, H; Villegas, M; Wiedenmann, W; Wolf, G; Azzurri, P; Boucrot, J; Callot, O; Chen, S; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, Ph; Jacholkowska, A; Le Diberder, F; Lefrancois, J; Mutz, A M; Schune, M H; Serin, L; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Bettarini, S; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Fantechi, R; Ferrante, I; Fidecaro, F; Foa, L; Giammanco, A; Giassi, A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, F; Rizzo, G; Sanguinetti, G; Sciaba, A; Sguazzoni, G; Spagnolo, P; Steinberger, J; Tenchini, R; Vannini, C; Venturi, A; Verdini, P G; Awunor, O; Blair, G A; Cowan, G; Garcia-Bellido, A; Green, M G; Medcalf, T; Misiejuk, A; Strong, J A; Teixeira-Dias, P; Botterill, D R; Clifft, R W; Edgecock, T R; Edwards, M; Haywood, S J; Norton, P R; Tomalin, I R; Ward, J J; Bloch-Devaux, B; Boumediene, D; Colas, P; Emery, S; Fabbro, B; Kozanecki, W; Lancon, E; Lemaire, M C; Locci, E; Perez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Tuchming, B; Vallage, B; Black, S N; Dann, J H; Kim, H Y; Konstantinidis, N; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S
2013-01-01
Electroweak measurements performed with data taken at the electron-positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3~fb$^{-1}$ collected by the four LEP experiments ALEPH, DELPHI, L3 and OPAL, at centre-of-mass energies ranging from $130~GeV$ to $209~GeV$. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron-positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose-Einstein correlations between the two W decay systems arising ...
New Statistical Techniques in the Measurement of the inclusive Top Pair Production Cross Section
Ji?í Franc; Petr Bou?; Michal Št?pánek; Václav K?s
2014-12-12
We present several different types of multivariate statistical techniques used in the measurement of the inclusive top pair production cross section in $p \\bar{p}$-collisions at $\\sqrt{s} = 1.96 \\text{TeV}$ employing the full RunII data ($9.7\\textrm{ fb}^{-1}$) collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair decays containing one electron or muon and at least two jets. We proceed various statistical homogeneity tests such as Anderson - Darling, Kolmogorov - Smirnov, and $\\varphi$-divergences tests to determine, which variables have good data-MC agreement, as well as a good separation power. We adjusted all tests for using weighted empirical distribution functions. Further we separate $t\\bar{t}$ signal from the background by the application of Generalized Linear Models, Gaussian Mixture Models, Neural Networks with Switching Units and confront them with familiar methods from ROOT TMVA package such as Boosted Decision Trees, and Multi-layer Perceptron. We compare results by area under receiver operating characteristic curve and verify the quality of the discrimination from all methods.
The curious case of HD 41248. A pair of static signals buried behind red noise
Jenkins, J. S.; Tuomi, M.
2014-10-20
Gaining a better understanding of the effects of stellar-induced radial velocity noise is critical for the future of exoplanet studies since the discovery of the lowest-mass planets using this method will require us to go below the intrinsic stellar noise limit. An interesting test case in this respect is that of the southern solar analog HD 41248. The radial velocity time series of this star has been proposed to contain either a pair of signals with periods of around 18 and 25 days, which could be due to a pair of resonant super-Earths, or a single and varying 25 day signal that could arise due to a complex interplay between differential rotation and modulated activity. In this work, we build up more evidence for the former scenario, showing that the signals are still clearly significant, even after more than 10 yr of observations, and they likely do not change in period, amplitude, or phase as a function of time, the hallmarks of static Doppler signals. We show that over the last two observing seasons, this star was more intrinsically active and the noise reddened, highlighting why better noise models are needed to find the lowest amplitude signals, in particular, models that consider noise correlations. This analysis shows that there is still sufficient evidence for the existence of two super-Earths on the edge of, or locked into, a 7:5 mean motion resonance orbiting HD 41248.
The Contribution of Electron-Positron Pair Production to the Vacuum Energy
Durney, Bernard R
2012-01-01
The vacuum, defined as the state where no particles can be observed, is interpreted here to imply that the lifetime of the e-p pair should be equal to the Planck time. Concerning the title's subject, a perfect theory would require that the true vacuum expectation value of the operator associated with pair production, be compatible with the normalization of the true vacuum. At present, a calculation of the vacuum energy based on Feynman diagrams reveals a serious difficulty: if only second order terms of the S-matrix are retained, and because there are no external lines, it follows that the space-time integrations over the coordinates, involved in the calculation of the vacuum expectation value of the S-matrix, give rise to two identical delta functions: the amplitude is thus proportional to the space-time volume of integration, L4. The square of the amplitude defies then any physically meaningful interpretation. One is faced here with two evils: modify the interaction Lagrangian so that the amplitude becomes ...
Marchetti, P A; Su, Z B; Yu, L
2011-01-01
Within a gauge approach to the t-J model, we propose a new, non-BCS mechanism of superconductivity for underdoped cuprates. We implement the no-double occupancy constraint with a (semionic) slave-particle formalism. The dopant generates a vortex-like quantum distortion of the AF background centered on the empty sites, with opposite chirality for cores on the two N\\'eel sublattices. Empty sites are described in terms of spinless fermionic holons and the long-range attraction between spin vortices on two opposite N\\'eel sublattices is the holon pairing force, leading eventually to SC. The spin fluctuations are described by bosonic spinons with a gap generated by scattering on spin vortices. Due to the occupation constraint, there is a gauge attraction between holon and spinon, binding them into a physical hole. Through gauge interaction the spin vortex attraction induces the formation of spin-singlet RVB pairs reducing the spinon gap. Lowering T, there are two crossovers as precursors of the SC transition: at t...
Twisted injectivity in projected entangled pair states and the classification of quantum phases
Buerschaper, Oliver
2014-12-15
We introduce a class of projected entangled pair states (PEPS) which is based on a group symmetry twisted by a 3-cocycle of the group. This twisted symmetry is expressed as a matrix product operator (MPO) with bond dimension greater than 1 and acts on the virtual boundary of a PEPS tensor. We show that it gives rise to a new standard form for PEPS from which we construct a family of local Hamiltonians which are gapped, frustration-free and include fixed points of the renormalization group flow. Based on this insight, we advance the classification of 2D gapped quantum spin systems by showing how this new standard form for PEPS determines the emergent topological order of these local Hamiltonians. Specifically, we identify their universality class as DIJKGRAAF–WITTEN topological quantum field theory (TQFT). - Highlights: • We introduce a new standard form for projected entangled pair states via a twisted group symmetry which is given by nontrivial matrix product operators. • We construct a large family of gapped, frustration-free Hamiltonians in two dimensions from this new standard form. • We rigorously show how this new standard form for low energy states determines the emergent topological order.
Search for neutral MSSM Higgs bosons decaying to a pair of tau leptons in pp collisions
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, V.
2014-10-28
A search for neutral Higgs bosons in the minimal supersymmetric extension of the standard model (MSSM) decaying to tau-lepton pairs in pp collisions is performed, using events recorded by the CMS experiment at the LHC. The dataset corresponds to an integrated luminosity of 24.6 fb?¹, with 4.9 fb?¹ at 7 TeV and 19.7 fb?¹ at 8 TeV. To enhance the sensitivity to neutral MSSM Higgs bosons, the search includes the case where the Higgs boson is produced in association with a b-quark jet. No excess is observed in the tau-lepton-pair invariant mass spectrum. Exclusion limits are presented in the MSSMmore »parameter space for different benchmark scenarios, mhmax, mhmod+ , mhmod– , light-stop, light-stau, ?-phobic, and low-mH. Upper limits on the cross section times branching fraction for gluon fusion and b-quark associated Higgs boson production are also given.« less
Search for neutral MSSM Higgs bosons decaying to a pair of tau leptons in pp collisions
Khachatryan, V.
2014-10-28
A search for neutral Higgs bosons in the minimal supersymmetric extension of the standard model (MSSM) decaying to tau-lepton pairs in pp collisions is performed, using events recorded by the CMS experiment at the LHC. The dataset corresponds to an integrated luminosity of 24.6 fb?¹, with 4.9 fb?¹ at 7 TeV and 19.7 fb?¹ at 8 TeV. To enhance the sensitivity to neutral MSSM Higgs bosons, the search includes the case where the Higgs boson is produced in association with a b-quark jet. No excess is observed in the tau-lepton-pair invariant mass spectrum. Exclusion limits are presented in the MSSM parameter space for different benchmark scenarios, m_{h}^{max}, m_{h}^{mod+} , m_{h}^{mod–} , light-stop, light-stau, ?-phobic, and low-m_{H}. Upper limits on the cross section times branching fraction for gluon fusion and b-quark associated Higgs boson production are also given.
Lim, Lih-King; Lazarides, Achilleas; Morais Smith, C.; Hemmerich, Andreas
2010-07-15
We study fermionic superfluidity in an ultracold Bose-Fermi mixture loaded into a square optical lattice subjected to a staggered flux. While the bosons form a Bose-Einstein condensate at very low temperature and weak interaction, the interacting fermions experience an additional long-ranged attractive interaction mediated by phonons in the bosonic condensate. This leads us to consider a generalized Hubbard model with on-site and nearest-neighbor attractive interactions, which give rise to two competing pairing channels. We use the Bardeen-Cooper-Schrieffer theory to determine the regimes where distinct fermionic superfluids are stabilized and find that the nonlocal pairing channel favors a superfluid state which breaks both the gauge and the lattice symmetries, similar to unconventional superconductivity occurring in some strongly correlated systems. Furthermore, the particular structure of the single-particle spectrum leads to unexpected consequences, for example, a dome-shaped superfluid region in the temperature versus filing fraction phase diagram, with a normal phase that contains much richer physics than a Fermi liquid. Notably, the relevant temperature regime and coupling strength are readily accessible in state of the art experiments with ultracold trapped atoms.
Johnson, John Asher [California Institute of Technology, Department of Astrophysics, MC 249-17, Pasadena, CA 91125 (United States); Payne, Matthew; Ford, Eric B. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, P.O. Box 112055, Gainesville, FL 32611-2055 (United States); Howard, Andrew W.; Marcy, Geoffrey W. [Department of Astronomy, University of California, Mail Code 3411, Berkeley, CA 94720 (United States); Clubb, Kelsey I. [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Bowler, Brendan P. [Institute for Astronomy, University of Hawai'i, Honolulu, HI 96822 (United States); Henry, Gregory W. [Center of Excellence in Information Systems, Tennessee State University, 3500 John A. Merritt Boulevard, Box 9501, Nashville, TN 37209 (United States); Fischer, Debra A.; Brewer, John M.; Schwab, Christian [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Reffert, Sabine [ZAH-Landessternwarte, Koenigstuhl 12, D-69117 Heidelberg (Germany); Lowe, Thomas B., E-mail: johnjohn@astro.caltech.edu [UCO/Lick Observatory, Santa Cruz, CA 95064 (United States)
2011-01-15
We report radial velocity (RV) measurements of the G-type subgiants 24 Sextanis (= HD 90043) and HD 200964. Both are massive, evolved stars that exhibit periodic variations due to the presence of a pair of Jovian planets. Photometric monitoring with the T12 0.80 m APT at Fairborn Observatory demonstrates both stars to be constant in brightness to {<=}0.002 mag, thus strengthening the planetary interpretation of the RV variations. Based on our dynamical analysis of the RV time series, 24 Sex b, c have orbital periods of 452.8 days and 883.0 days, corresponding to semimajor axes 1.333 AU and 2.08 AU, and minimum masses 1.99 M{sub Jup} and 0.86 M{sub Jup}, assuming a stellar mass M{sub *}= 1.54 M{sub sun}. HD 200964 b, c have orbital periods of 613.8 days and 825.0 days, corresponding to semimajor axes 1.601 AU and 1.95 AU, and minimum masses 1.99 M{sub Jup} and 0.90 M{sub Jup}, assuming M{sub *}= 1.44 M{sub sun}. We also carry out dynamical simulations to properly account for gravitational interactions between the planets. Most, if not all, of the dynamically stable solutions include crossing orbits, suggesting that each system is locked in a mean-motion resonance that prevents close encounters and provides long-term stability. The planets in the 24 Sex system likely have a period ratio near 2:1, while the HD 200964 system is even more tightly packed with a period ratio close to 4:3. However, we caution that further RV observations and more detailed dynamical modeling will be required to provide definitive and unique orbital solutions for both cases, and to determine whether the two systems are truly resonant.
Predissociation of high-lying Rydberg states of molecular iodine via ion-pair states
Bogomolov, Alexandr S. [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation)] [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation); Grüner, Barbara; Mudrich, Marcel [Physikalisches Institut, Universität Freiburg, D-79104 Freiburg (Germany)] [Physikalisches Institut, Universität Freiburg, D-79104 Freiburg (Germany); Kochubei, Sergei A. [Institute of Semiconductor Physics, ac. Lavrent'yev ave., 13, Novosibirsk 630090 (Russian Federation)] [Institute of Semiconductor Physics, ac. Lavrent'yev ave., 13, Novosibirsk 630090 (Russian Federation); Baklanov, Alexey V. [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation) [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090 (Russian Federation)
2014-03-28
Velocity map imaging of the photofragments arising from two-photon photoexcitation of molecular iodine in the energy range 73?500–74?500 cm{sup ?1} covering the bands of high-lying gerade Rydberg states [{sup 2}?{sub 1/2}]{sub c}6d;0{sub g}{sup +} and [{sup 2}?{sub 1/2}]{sub c}6d;2{sub g} has been applied. The ion signal was dominated by the atomic fragment ion I{sup +}. Up to 5 dissociation channels yielding I{sup +} ions with different kinetic energies were observed when the I{sub 2} molecule was excited within discrete peaks of Rydberg states and their satellites in this region. One of these channels gives rise to images of I{sup +} and I{sup ?} ions with equal kinetic energy indicating predissociation of I{sub 2} via ion-pair states. The contribution of this channel was up to about 50% of the total I{sup +} signal. The four other channels correspond to predissociation via lower lying Rydberg states giving rise to excited iodine atoms providing I{sup +} ions by subsequent one-photon ionization by the same laser pulse. The ratio of these channels varied from peak to peak in the spectrum but their total ionic signal was always much higher than the signal of (2 + 1) resonance enhanced multi-photon ionization of I{sub 2}, which was previously considered to be the origin of ionic signal in this spectral range. The first-tier E0{sub g}{sup +} and D{sup ?}2{sub g} ion-pair states are concluded to be responsible for predissociation of Rydberg states [{sup 2}?{sub 1/2}]{sub c}6d;0{sub g}{sup +} and [{sup 2}?{sub 1/2}]{sub c}6d;2{sub g}, respectively. Further predissociation of these ion-pair states via lower lying Rydberg states gives rise to excited I(5s{sup 2}5p{sup 4}6s{sup 1}) atoms responsible for major part of ion signal. The isotropic angular distribution of the photofragment recoil directions observed for all channels indicates that the studied Rydberg states are long-lived compared with the rotational period of the I{sub 2} molecule.
Wu, Gang; Yaffe, Martin J.; Mainprize, James G.
2013-10-15
Purpose: The order in which the projection views are employed in the reconstruction of tomosynthesis by iterative algorithms, such as simultaneous algebraic reconstruction technique and maximum likelihood, has a strong effect on the rate of convergence, accuracy, and the edge-blurring artifacts in the reconstructed image. The purpose of this investigation was to characterize and evaluate the effects of ordering schemes on image quality for breast tomosynthesis reconstruction and to explore a new constrained paired-view technique that could provide reduction of reconstruction artifacts. In this work, the authors compared several different ordering schemes and characterized the image quality and the formation of out-of-plane artifacts. Furthermore, a new normalization method is presented. It produces more accurate reconstructions with reduced artifacts comparing to the standard method of sequential ordering.Methods: In addition to visual assessment of image quality, several indices such as the signal-difference-to-noise ratio, the artifact-spread function, and the lesion detectability (d{sup ?}) were computed to quantitatively evaluate the effect of ordering scheme. The sets of breast tomosynthesis projection images were simulated for reconstruction; one set had uniform background (white noise only) and the other two contained both anatomic background and quantum noise. Clinical breast images were also studied for comparison.Results: The authors have quantified the image quality in reconstructed slices for a range of tumor sizes. The authors’ proposed method provides better performance for all of the metrics tested (contrast, d{sup ?}, and the level of artifacts) both for the uniform phantom case and in the presence of anatomical structure.Conclusions: The paired projection normalization provides better performance in the image quality of the reconstructed slices, and results in a lower level of artifacts in the Z direction. This implies that even a relatively simple method like the “side-to-side” sequence, which pairs two symmetrical projections with equal angular distance from the central projection, would achieve better reconstructed image quality than the conventional “step-by-step” method, which uses sequential projections one after another.
Excitations and the tangent space of projected entangled-pair states
Laurens Vanderstraeten; Frank Verstraete; Jutho Haegeman
2015-07-08
We introduce a variational ansatz for elementary excitations of two-dimensional quantum spin systems, directly in the thermodynamic limit, based on the formalism of projected entangled-pair states (PEPS). Solving the corresponding variational problem requires the evaluation of momentum transformed two-point and three-point correlation functions on a PEPS background, which we can compute efficiently by introducing a variation of the corner transfer matrix. Our approach can be readily extended to topologically non-trivial excitations (anyons) and is illustrated for the elementary excitations in the Affleck-Lieb-Kennedy-Tasaki model on the square lattice and a perturbed version of Kitaev's toric code. These developments give direct access to the low-energy sector of strongly correlated two-dimensional quantum systems and allow for the formulation of improved optimization algorithms for determining a variational PEPS ground state approximation.
Homoclinic orbits and chaos in a pair of parametrically-driven coupled nonlinear resonators
Eyal Kenig; Yuriy A. Tsarin; Ron Lifshitz
2010-07-22
We study the dynamics of a pair of parametrically-driven coupled nonlinear mechanical resonators of the kind that is typically encountered in applications involving microelectromechanical and nanoelectromechanical systems (MEMS & NEMS). We take advantage of the weak damping that characterizes these systems to perform a multiple-scales analysis and obtain amplitude equations, describing the slow dynamics of the system. This picture allows us to expose the existence of homoclinic orbits in the dynamics of the integrable part of the slow equations of motion. Using a version of the high-dimensional Melnikov approach, developed by Kovacic and Wiggins [Physica D, 57, 185 (1992)], we are able to obtain explicit parameter values for which these orbits persist in the full system, consisting of both Hamiltonian and non-Hamiltonian perturbations, to form so-called Shilnikov orbits, indicating a loss of integrability and the existence of chaos. Our analytical calculations of Shilnikov orbits are confirmed numerically.
CP violation and electric-dipole-moment at low energy tau-pair production
J. Bernabeu; G. A. Gonzalez-Sprinberg; J. Vidal
2004-10-11
CP violation at low energy is investigated at the tau electromagnetic vertex. High statistics at B factories, and on top of the Upsilon resonances, allows a detailed investigation of CP-odd observables related to the tau-pair production. The contribution of the tau electric dipole moment is considered in detail. We perform an analysis independent from the high energy data by means of correlation and linear spin observables at low energy. We show that different CP-odd asymmetries, associated to the normal-transverse and normal-longitudinal correlation terms can be measured at low energy accelerators, both at resonant and non resonant energies. These observables allow to put stringent and independent bounds to the tau electric dipole moment that are competitive with other high or low energy results.
Associated production of a top pair and a Higgs boson beyond NLO
Broggio, Alessandro; Pecjak, Ben D; Signer, Adrian; Yang, Li Lin
2015-01-01
We consider soft gluon emission corrections to the production of a top-antitop pair in association with a Higgs boson at hadron colliders. In particular, we present a soft-gluon resummation formula for this production process and gather all elements needed to evaluate it at next-to-next-to-leading logarithmic order. We employ these results to obtain approximate next-to-next-to-leading order (NNLO) formulas, and implement them in a bespoke parton-level Monte Carlo program which can be used to calculate the total cross section along with arbitrary differential distributions. We use this tool to study the phenomenological impact of the approximate NNLO corrections, finding that they increase the total cross section and the differential distributions which we evaluated in this work.
D'Angelo, M; Sgattoni, A; Pegoraro, F; Macchi, A
2015-01-01
The evolution of the filamentation instability produced by two counter-streaming pair plasmas is studied with particle-in-cell (PIC) simulations in both one (1D) and two (2D) spatial dimensions. Radiation friction effects on particles are taken into account. After an exponential growth of both the magnetic field and the current density, a nonlinear quasi-stationary phase sets up characterized by filaments of opposite currents. During the nonlinear stage, a strong broadening of the particle energy spectrum occurs accompanied by the formation of a peak at twice their initial energy. A simple theory of the peak formation is presented. The presence of radiative losses does not change the dynamics of the instability but affects the structure of the particle spectra.
Advanced Residential Envelopes for Two Pair of Energy-Saver Homes
Miller, William A [ORNL] [ORNL; Karagiozis, Achilles N [ORNL] [ORNL; Kosny, Jan [ORNL] [ORNL; Shrestha, Som S [ORNL] [ORNL; Christian, Jeffrey E [ORNL] [ORNL; Kohler, Christian [Lawrence Berkeley National Laboratory (LBNL)] [Lawrence Berkeley National Laboratory (LBNL); Dinse, David [Tennessee Valley Authority (TVA)] [Tennessee Valley Authority (TVA)
2010-01-01
Four homes are under construction in the Tennessee Valley to showcase homes that are at least 50% energy savers as compared to homes built to local code. Schaad Companies LLC, the Tennessee Valley Authority (TVA), the Oak Ridge National Laboratory (ORNL), Barber McMurry Architects (BMA) and the Department of Energy (DOE) intend to transform new and existing buildings into affordable, durable and efficient housing. All formed a private- and federal-sector consortium herein called the Zero Energy Building Research Alliance (ZEBRA). The consortium is about to evaluate the market viability for making two pairs of homes 50 percent more energy efficient than homes of similar size and style. Achieving the goal requires the most advanced building technology, products and techniques available. The homes are located on adjacent cul-de-sacs and are unoccupied for the duration of a two-year field study, thereby eliminating the confounding issue of occupancy habits.
Takuya Kanazawa; Tilo Wettig
2014-09-28
We generalize QCD at asymptotically large isospin chemical potential to an arbitrary even number of flavors. We also allow for small quark chemical potentials, which stress the coincident Fermi surfaces of the paired quarks and lead to a sign problem in Monte Carlo simulations. We derive the corresponding low-energy effective theory in both $p$- and $\\epsilon$-expansion and quantify the severity of the sign problem. We construct the random matrix theory describing our physical situation and show that it can be mapped to a known random matrix theory at low baryon density so that new insights can be gained without additional calculations. In particular, we explain the Silver Blaze phenomenon at high isospin density. We also introduce stressed singular values of the Dirac operator and relate them to the pionic condensate. Finally we comment on extensions of our work to two-color QCD.
Radiative Emission of Neutrino Pairs in Atoms and Light Sterile Neutrinos
D. N. Dinh; S. T. Petcov
2015-01-22
The process of Radiative Emission of Neutrino Pair (RENP) in atoms is sensitive to the absolute neutrino mass scale, the type of spectrum neutrino masses obey and the nature - Dirac or Majorana - of massive neutrinos. We analyse the possibility to test the hypothesis of existence of neutrinos with masses at the eV scale coupled to the electron in the weak charged lepton current in an RENP experiment. The presence of eV scale neutrinos in the neutrino mixing is associated with the existence of sterile neutrinos which mix with the active flavour neutrinos. At present there are a number of hints for active-sterile neutrino oscillations driven by $\\Delta m^2 \\sim 1~{\\rm eV^2}$. We perform a detailed analysis of the RENP phenomenology within the "3 + 1" scheme with one sterile neutrino.
Radiative Emission of Neutrino Pairs in Atoms and Light Sterile Neutrinos
Dinh, D N
2014-01-01
The process of Radiative Emission of Neutrino Pair (RENP) in atoms is sensitive to the absolute neutrino mass scale, the type of spectrum neutrino masses obey and the nature - Dirac or Majorana - of massive neutrinos. We analyse the possibility to test the hypothesis of existence of neutrinos with masses at the eV scale coupled to the electron in the weak charged lepton current in an RENP experiment. The presence of eV scale neutrinos in the neutrino mixing is associated with the existence of sterile neutrinos which mix with the active flavour neutrinos. At present there are a number of hints for active-sterile neutrino oscillations driven by $\\Delta m^2 \\sim 1~{\\rm eV^2}$. We perform a detailed analysis of the RENP phenomenology within the "3 + 1" scheme with one sterile neutrino.
Top pair production at a future $e^+e^-$ machine in a composite Higgs scenario
Daniele Barducci; Stefania De Curtis; Stefano Moretti; Giovanni Marco Pruna
2015-04-21
The top quark plays a central role in many New Physics scenarios and in understanding the details of Electro-Weak Symmetry Breaking. In the short- and mid-term future, top-quark studies will mainly be driven by the experiments at the Large Hadron Collider. Exploration of top quarks will, however, be an integral part of particle physics studies at any future facility and an $e^+ e^-$ collider will have a very comprehensive top-quark physics program. We discuss the possibilities of testing NP in the top-quark sector within a composite Higgs scenario through deviations from the Standard Model in top pair production for different Centre-of-Mass energy options of a future $e^+e^-$ machine. In particular, we focus on precision studies of the top-quark sector at a CM energy ranging from 370 GeV up to 3 TeV.