Uncertainty evaluation of delayed neutron decay parameters
Wang, Jinkai
2009-05-15T23:59:59.000Z
parameters fit their individual measurement data well in spite of these differences. This dissertation focuses on evaluation of the errors and methods of delayed neutron relative yields and decay constants for thermal fission of U-235. Various numerical...
Uncertainty evaluation of delayed neutron decay parameters
Wang, Jinkai
2009-05-15T23:59:59.000Z
parameters fit their individual measurement data well in spite of these differences. This dissertation focuses on evaluation of the errors and methods of delayed neutron relative yields and decay constants for thermal fission of U-235. Various numerical...
BARYON DECAY PARAMETERS Written 1996 by E.D. Commins (University of California, Berke-
by standard means [5] and are analogous to formulae for nuclear beta decay [6]. We use the notation of Ref. 6 in the Listings for neutron beta decay. For comparison with experi- ments at higher q2, it is necessary to modify been measured precisely only in neutron decay (and in 19Ne nuclear beta decay), and the results
D. W. Sciama
1998-05-13T23:59:59.000Z
Various recent observational developments are here used to make a more critical analysis of the parameter space of the decaying neutrino theory for the ionisation of the interstellar medium. These developments involve phenomena inside our Galaxy, outside the Galaxy but at essentially zero red shift, and at large red shifts. This new analysis leads to a viable theory with a decay lifetime of $2{\\pm}1\\times 10^{23}$ sec, a decay photon energy of $13.7{\\pm}0.1$ eV, and a mass for the decaying neutrino of $27.4 {\\pm}0.2$ eV. These parameters, when combined with some known astronomical quantities, lead to predictions for the intensity, the wavelength and the width of the decay line produced by neutrinos lying within one optical depth of the sun $({\\sim} 1/2 pc)$. One finds an intensity in the line of $350^{+350}_{-117}$ photons $cm^{-2} sec^{-1}$, a wavelength of $905\\pm7\\AA$, and a width $\\sim1\\AA$. These predictions are relevant for the observations about to be made by the EURD ultra-violet detector which is currently in Earth orbit on board the Spanish MINISAT 01 satellite.
A Monte Carlo study of the distribution of parameter estimators in a dual exponential decay model
Garcia, Raul
1969-01-01T23:59:59.000Z
of an estimate of the reliability of the parameter estimates calculated. In 1965, Bell and Garcia [2] developed a computer program which permits a solution of the parameters without the time-consuming effort of manual calcu- lations. The same year, Rossing [3...A MONTE CARLO STUDY OF THE DISTRIBUTION OF PARAMETER ESTIMATORS IN A DUAL EXPONENTIAL DECAY MODEL A Thesis by SAUL GARCIA Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree...
Assadullahi, Hooshyar; Wands, David [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth PO1 3FX (United Kingdom); Firouzjahi, Hassan [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P. O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Namjoo, Mohammad Hossein, E-mail: hooshyar.assadullahi@port.ac.uk, E-mail: firouz@mail.ipm.ir, E-mail: mh.namjoo@mail.ipm.ir, E-mail: david.wands@port.ac.uk [Yukawa Institute for theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)
2013-03-01T23:59:59.000Z
We study primordial density perturbations generated by the late decay of a curvaton field whose decay rate may be modulated by the local value of another isocurvature field, analogous to models of modulated reheating at the end of inflation. We calculate the primordial density perturbation and its local-type non-Gaussianity using the sudden-decay approximation for the curvaton field, recovering standard curvaton and modulated reheating results as limiting cases. We verify the Suyama-Yamaguchi inequality between bispectrum and trispectrum parameters for the primordial density field generated by multiple field fluctuations, and find conditions for the bound to be saturated.
Constraints on light neutrino parameters derived from the study of neutrinoless double beta decay
Sabin Stoica; Andrei Neacsu
2014-05-02T23:59:59.000Z
The study of the neutrinoless double beta ($0 \\beta\\beta$) decay mode can provide us with important information on the neutrino properties, particularly on the electron neutrino absolute mass. In this work we revise the present constraints on the neutrino mass parameters derived from the $0 \\beta\\beta$ decay analysis of the experimentally interesting nuclei. We use the latest results for the phase space factors (PSFs) and nuclear matrix elements (NMEs), as well as for the experimental lifetimes limits. For the PSFs we use values computed with an improved method reported very recently. For the NMEs we use values chosen from literature on a case-by-case basis, taking advantage of the consensus reached by the community on several nuclear ingredients used in their calculation. Thus, we try to restrict the range of spread of the NME values calculated with di?erent methods and, hence, to reduce the uncertainty in deriving limits for the Majorana neutrino mass parameter. Our results may be useful to have an up-date image on the present neutrino mass sensitivities associated with $0 \\beta\\beta$ measurements for different isotopes and to better estimate the range of values of the neutrino masses that can be explored in the future double beta decay (DBD) experiments.
Taylor, Frank E.
A measurement of the parity-violating decay asymmetry parameter, ?[subscript b], and the helicity amplitudes for the decay ?[0 over b] ? J/?(?[superscript +]?[superscript ?])?[superscript 0](p?[superscript ?]) is reported. ...
New Physics from NSIs in charm Decays
Shakeel Mahmood; Farida Tahir; Azeem Mir
2014-11-04T23:59:59.000Z
We study rare decays of Charm in NSIs. We calculate the NSIs Branching ratios of these decays. There is a strong dependence of these on new physics parameter. They provide, stringent constraints on free parameter in tau.
Snoek, Hella Leonie; /Vrije U., Amsterdam
2011-11-28T23:59:59.000Z
This thesis describes the measurement of the branching fractions of the suppressed charmed B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays and the non-resonant B{sup 0} {yields} D{sup (*)-} {eta}{pi}{sup +} decays in approximately 230 million {Upsilon}(4S) {yields} B{bar B} events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10{sup -6}. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle {gamma}, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle {gamma} can be performed using the decays of neutral B mesons. The B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay is sensitive to the angle {gamma} and, in comparison to the current decays that are being employed, could significantly enhance the measurement of this angle. However, the low expected branching fraction for the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay channels could severely impact the measurement. A prerequisite of the measurement of the CKM angle is the observation of the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay on which this thesis reports. The BABAR experiment consists of the BABAR detector and the PEP-II e{sup +}e{sup -} collider. The design of the experiment has been optimized for the study of CP violation in the decays of neutral B mesons but is also highly suitable for the search for rare B decays such as the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay. The PEP-II collider operates at the {Upsilon}(4S) resonance and is a clean source of B{bar B} meson pairs.
Suzuki, Mahiko
2005-05-13T23:59:59.000Z
We extend the perturbative argument of helicity amplitudes to the two-body baryonic decays of B decays.
Measurement of CP violation parameters in B<[superscript 0] ? DK[superscript *0] decays
Aaij, R.
An analysis of B[superscript 0] ? DK[superscript *0] decays is presented, where D represents an admixture of D[superscript 0] and [bar over D][superscript 0] mesons reconstructed in four separate final states: K[superscript ...
Roberto Iengo; Jorge G. Russo
2006-02-20T23:59:59.000Z
We explain simple semi-classical rules to estimate the lifetime of any given highly-excited quantum state of the string spectrum in flat spacetime. We discuss both the decays by splitting into two massive states and by massless emission. As an application, we study a solution describing a rotating and pulsating ellipse which becomes folded at an instant of time -- the ``squashing ellipse''. This string interpolates between the folded string with maximum angular momentum and the pulsating circular string. We explicitly compute the quantum decay rate for the corresponding quantum state, and verify the basic rules that we propose. Finally, we give a more general (4-parameter) family of closed string solutions representing rotating and pulsating elliptical strings.
Tianjun Li; Dimitri V. Nanopoulos; Joel W. Walker
2010-09-10T23:59:59.000Z
We consider proton decay in the testable flipped SU(5) X U(1)_X models with TeV-scale vector-like particles which can be realized in free fermionic string constructions and F-theory model building. We significantly improve upon the determination of light threshold effects from prior studies, and perform a fresh calculation of the second loop for the process p \\to e^+ \\pi^0 from the heavy gauge boson exchange. The cumulative result is comparatively fast proton decay, with a majority of the most plausible parameter space within reach of the future Hyper-Kamiokande and DUSEL experiments. Because the TeV-scale vector-like particles can be produced at the LHC, we predict a strong correlation between the most exciting particle physics experiments of the coming decade.
Precise Measurement of the CP Violation Parameter sin2?1 in B??(cc?)K? Decays
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Adachi, I.; Aihara, H.; Asner, D. M.; Aulchenko, V.; Aushev, T.; Aziz, T.; Bakich, A. M.; Bay, A.; Bhardwaj, V.; Bhuyan, B.; Bischofberger, M.; Bondar, A.; Bozek, A.; Bra?ko, M.; Browder, T. E.; Chen, P.; Cheon, B. G.; Chilikin, K.; Chistov, R.; Cho, K.; Choi, S.-K.; Choi, Y.; Dalseno, J.; Danilov, M.; Doležal, Z.; Drásal, Z.; Eidelman, S.; Epifanov, D.; Fast, J. E.; Gaur, V.; Gabyshev, N.; Garmash, A.; Goh, Y. M.; Golob, B.; Haba, J.; Hara, K.; Hara, T.; Hayasaka, K.; Hayashii, H.; Higuchi, T.; Horii, Y.; Hoshi, Y.; Hou, W.-S.; Hsiung, Y. B.; Hyun, H. J.; Iijima, T.; Ishikawa, A.; Itoh, R.; Iwabuchi, M.; Iwasaki, Y.; Iwashita, T.; Julius, T.; Kapusta, P.; Katayama, N.; Kawasaki, T.; Kichimi, H.; Kiesling, C.; Kim, H. J.; Kim, H. O.; Kim, J. B.; Kim, J. H.; Kim, K. T.; Kim, Y. J.; Kinoshita, K.; Ko, B. R.; Koblitz, S.; Kodyš, P.; Korpar, S.; Križan, P.; Krokovny, P.; Kuhr, T.; Kumar, R.; Kumita, T.; Kuzmin, A.; Kwon, Y.-J.; Lange, J. S.; Lee, S.-H.; Li, J.; Li, Y.; Liu, C.; Liu, Y.; Liu, Z. Q.; Liventsev, D.; Louvot, R.; Matvienko, D.; McOnie, S.; Miyabayashi, K.; Miyata, H.; Miyazaki, Y.; Mizuk, R.; Mohanty, G. B.; Mori, T.; Muramatsu, N.; Nakano, E.; Nakao, M.; Nakazawa, H.; Neubauer, S.; Nishida, S.; Nishimura, K.; Nitoh, O.; Ogawa, S.; Ohshima, T.; Okuno, S.; Olsen, S. L.; Onuki, Y.; Ozaki, H.; Pakhlov, P.; Pakhlova, G.; Park, H. K.; Park, K. S.; Pedlar, T. K.; Pestotnik, R.; Petri?, M.; Piilonen, L. E.; Poluektov, A.; Röhrken, M.; Rozanska, M.; Sahoo, H.; Sakai, K.; Sakai, Y.; Sanuki, T.; Sato, Y.; Schneider, O.; Schwanda, C.; Schwartz, A. J.; Senyo, K.; Shebalin, V.; Shen, C. P.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Sibidanov, A.; Simon, F.; Singh, J. B.; Smerkol, P.; Sohn, Y.-S.; Sokolov, A.; Solovieva, E.; Stani?, S.; Stari?, M.; Sumihama, M.; Sumisawa, K.; Sumiyoshi, T.; Tanaka, S.; Tatishvili, G.; Teramoto, Y.; Tikhomirov, I.; Trabelsi, K.; Tsuboyama, T.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Ushiroda, Y.; Vahsen, S. E.; Varner, G.; Varvell, K. E.; Vinokurova, A.; Vorobyev, V.; Wang, C. H.; Wang, M.-Z.; Wang, P.; Watanabe, M.; Watanabe, Y.; Williams, K. M.; Won, E.; Yabsley, B. D.; Yamamoto, H.; Yamashita, Y.; Yamauchi, M.; Yusa, Y.; Zhang, Z. P.; Zhilich, V.; Zupanc, A.; Zyukova, O.; The Belle Collaboration
2012-04-01T23:59:59.000Z
We present a precise measurement of the CP violation parameter sin2?1 and the direct CP violation parameter Af using the final data sample of 772×10? BB¯¯¯ pairs collected at the ?(4S) resonance with the Belle detector at the KEKB asymmetric-energy e?e? collider. One neutral B meson is reconstructed in a J/?K0S, ?(2S)K0S, ?c1K0S, or J/?K0L CP eigenstate and its flavor is identified from the decay products of the accompanying B meson. From the distribution of proper-time intervals between the two B decays, we obtain the following CP violation parameters: sin2?1=0.667±0.023(stat)±0.012(syst) and Af=0.006±0.016(stat)±0.012(syst).
Bevan, A.J.
2006-06-07T23:59:59.000Z
Rare hadronic B-meson decays allow us to study CP violation. The class of B-decays final states containing two vector mesons provides a rich set of angular correlation observables to study. This article reviews some of the recent experimental results from the BABAR and Belle collaborations.
Mishra, Kalanand; /Nehru U.
2008-02-22T23:59:59.000Z
The authors present measurements of the relative branching ratios, Dalitz plot structures and CP-asymmetry values in the three-body singly Cabibbo-suppressed decays D{sup 0} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup 0} and D{sup 0} {yields} K{sup -}K{sup +}{pi}{sup 0} using data collected by the BABAR detector at the PEP-II asymmetric-energy ring at SLAC. The author applies the results of the D{sup 0} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup 0} analysis to extracting CP-violation parameters related to the CKM angle {gamma} (or {phi}{sub 3}) using the decay B{sup -} {yields} D{sub {pi}{sup +}{pi}{sup -}{pi}{sup 0}} K{sup -}.
Rare B Decays and B Decay Dynamics
William T. Ford
2005-10-20T23:59:59.000Z
I present some recent measurements of B meson decay rates to leptonic and charmless hadronic final states, as well as of CP-violation charge asymmetries and other features. I sketch the theoretical frameworks used to predict these, and indicate the level of agreement of the estimates with experiment.
Neutrinoless double beta decay
K. Zuber
2012-01-23T23:59:59.000Z
The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations are presented as well as the current status of experiments. Finally an outlook towards the future, work on nuclear matrix elements and alternative processes is given.
Steven R. Elliott; Petr Vogel
2002-02-27T23:59:59.000Z
The motivation, present status, and future plans of the search for the neutrinoless double beta decay are reviewed. It is argued that, motivated by the recent observations of neutrino oscillations, there is a reasonable hope that neutrinoless double beta decay corresponding to the neutrino mass scale suggested by oscillations, of about 50 meV, actually exists. The challenges to achieve the sensitivity corresponding to this mass scale, and plans to overcome them, are described.
Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; /Annecy, LAPP; Grauges, E.; /Barcelona, IFAE; Palano, A.; Pappagallo, M.; Pompili, A.; /Bari U. /INFN, Bari; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; /Beijing, Inst. High Energy Phys.; Eigen, G.; Ofte, I.; Stugu, B. /Bergen U. /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San
2005-07-27T23:59:59.000Z
The authors present a preliminary measurement of the CP-violating parameters in fully reconstructed B{sup 0} {yields} D{sup (*){+-}}{pi}{sup {-+}} and B{sup 0} {yields} D{sup {+-}}{rho}{sup {-+}} decays in approximately 232 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC.
Predicting Neutrinoless Double Beta Decay
M. Hirsch; Ernest Ma; J. W. F. Valle; A. Villanova del Moral
2005-07-12T23:59:59.000Z
We give predictions for the neutrinoless double beta decay rate in a simple variant of the A_4 family symmetry model. We show that there is a lower bound for the neutrinoless double beta decay amplitude even in the case of normal hierarchical neutrino masses, corresponding to an effective mass parameter |m_{ee}| >= 0.17 \\sqrt{\\Delta m^2_{ATM}}. This result holds both for the CP conserving and CP violating cases. In the latter case we show explicitly that the lower bound on |m_{ee}| is sensitive to the value of the Majorana phase. We conclude therefore that in our scheme, neutrinoless double beta decay may be accessible to the next generation of high sensitivity experiments.
Monotonic Local Decay Estimates
Avy Soffer
2011-10-29T23:59:59.000Z
For the Hamiltonian operator H = -{\\Delta}+V(x) of the Schr\\"odinger Equation with a repulsive potential, the problem of local decay is considered. It is analyzed by a direct method, based on a new, L^2 bounded, propagation observable. The resulting decay estimate, is in certain cases monotonic in time, with no "Quantum Corrections". This method is then applied to some examples in one and higher dimensions. In particular the case of the Wave Equation on a Schwarzschild manifold is redone: Local decay, stronger than the known ones are proved (minimal loss of angular derivatives and lower order of radial derivatives of initial data). The method developed here can be an alternative in some cases to the Morawetz type estimates, with L^2-multipliers replacing the first order operators. It provides an alternative to Mourre's method, by including thresholds and high energies.
WHY SEARCH FOR DOUBLE BETA DECAY?
Kayser, B.
2010-01-01T23:59:59.000Z
the search for neutrinoless double beta decay may prove verySearching for neutrinoless double beta decay is the onlysensitivity of neutrinoless double beta decay. The potential
Neutrinoless double beta decay
Petr Vogel
2006-11-17T23:59:59.000Z
The status of the search for neutrinoless double beta decay is reviewed. The effort to reach the sensitivity needed to cover the effective Majorana neutrino mass corresponding to the degenerate and inverted mass hierarchy is described. Various issues concerning the theory (and phenomenology) of the relation between the $0\
Neutrinoless Double Beta Decay
Heinrich Päs; Werner Rodejohann
2015-07-01T23:59:59.000Z
We review the potential to probe new physics with neutrinoless double beta decay $(A,Z) \\to (A,Z+2) + 2 e^-$. Both the standard long-range light neutrino mechanism as well as short-range mechanisms mediated by heavy particles are discussed. We also stress aspects of the connection to lepton number violation at colliders and the implications for baryogenesis.
Neutrinoless Double Beta Decay
Päs, Heinrich
2015-01-01T23:59:59.000Z
We review the potential to probe new physics with neutrinoless double beta decay $(A,Z) \\to (A,Z+2) + 2 e^-$. Both the standard long-range light neutrino mechanism as well as short-range mechanisms mediated by heavy particles are discussed. We also stress aspects of the connection to lepton number violation at colliders and the implications for baryogenesis.
Enrique Álvarez; Roberto Vidal
2011-11-09T23:59:59.000Z
The problem of the vacuum energy decay is studied through the analysis of the vacuum survival amplitude ${\\mathcal A}(z, z')$. Transition amplitudes are computed for finite time-span, $Z\\equiv z^\\prime-z$, and their {\\em late time} behavior is discussed up to first order in the coupling constant, $\\l$.
Parolo, Pietro Della Briotta; Ghosh, Rumi; Huberman, Bernardo A; Kaski, Kimmo; Fortunato, Santo
2015-01-01T23:59:59.000Z
The exponential growth in the number of scientific papers makes it increasingly difficult for researchers to keep track of all the publications relevant to their work. Consequently, the attention that can be devoted to individual papers, measured by their citation counts, is bound to decay rapidly. In this work we make a thorough study of the life-cycle of papers in different disciplines. Typically, the citation rate of a paper increases up to a few years after its publication, reaches a peak and then decreases rapidly. This decay can be described by an exponential or a power law behavior, as in ultradiffusive processes, with exponential fitting better than power law for the majority of cases. The decay is also becoming faster over the years, signaling that nowadays papers are forgotten more quickly. However, when time is counted in terms of the number of published papers, the rate of decay of citations is fairly independent of the period considered. This indicates that the attention of scholars depends on th...
Neutrino oscillations and neutrinoless double beta decay
D. Falcone; F. Tramontano
2001-03-16T23:59:59.000Z
The relation between neutrino oscillation parameters and neutrinoless double beta decay is studied, assuming normal and inverse hierarchies for Majorana neutrino masses. For normal hierarchy the crucial dependence on U_{e3} is explored. The link with tritium beta decay is also briefly discussed.
Nanal, Vandana [Dept. of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400 005 (India)
2011-11-23T23:59:59.000Z
At present, neutrinoless double beta decay is perhaps the only experiment that can tell us whether the neutrino is a Dirac or a Majorana particle. Given the significance of the 0{nu}{beta}{beta}, there is a widespread interest for these rare event studies employing a variety of novel techniques. This paper describes the current status of DBD experiments. The Indian effort for an underground NDBD experiment at the upcoming INO laboratory is also presented.
A. M. Sukhovoj; V. A. Khitrov
2008-09-15T23:59:59.000Z
The gamma-spectra were calculated for the set of different level densities and radiative strength functions. The sufficiently precise reproduction of the experiment is impossible without taking into account the influence of the process of the nucleons Cooper pairs breaking on any nuclei cascade gamma-decay parameters.
Shadov, M. B., E-mail: force86@bk.ru [Moscow State Institute of Electronics and Mathematics (Technical University) (Russian Federation)
2010-12-15T23:59:59.000Z
Concentration of excess charge carriers as a function of time in the course of photoconductivity decay has been calculated. The calculation takes into account the local disturbance of electroneutrality, which necessitates the use of the Poisson equation in the set of equations describing the given process. A rather cumbersome nonlinear differential equation has been derived by solving the new system. Criteria have been established and with the observance of these criteria it is possible to reduce that equation to a well-known equation conventionally used to describe the process of photoconductivity decay upon termination of a pulse of light.
Measurement of CP violation observables and parameters for the decays $B^{\\pm}\\to DK^{*\\pm}$
Aubert, Bernard; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison
2010-08-26T23:59:59.000Z
We study the decay B{sup -} {yields} DK*{sup -} using a sample of 379 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEP-II B-factory. We perform a 'GLW' analysis where the D meson decays into either a CP-even (CP+) eigenstate (K{sup +}K{sup -}, {pi}{sup +}{pi}{sup -}), CP-odd (CP-) eigenstate (K{sub S}{sup 0}{pi}{sup 0}, K{sub S}{sup 0}{phi}, K{sub S}{sup 0}{omega}) or a non-CP state (K{sup -}{pi}{sup +}). We also analyze D meson decays into K{sup +}{pi}{sup -} from a Cabibbo-favored {bar D}{sup 0} decay or doubly suppressed D{sup 0} decay ('ADS' analysis). We measure observables that are sensitive to the CKM angle {gamma}: the partial-rate charge asymmetries A{sub CP{+-}}, the ratios R{sub CP{+-}} of the B-decay branching fractions in CP{+-} and non-CP decay, the ratio R{sub ADS} of the charge-averaged branching fractions, and the charge asymmetry A{sub ADS} of the ADS decays: A{sub CP+} = 0.09 {+-} 0.13 {+-} 0.06, A{sub CP-} = -0.23 {+-} 0.21 {+-} 0.07, R{sub CP+} = 2.17 {+-} 0.35 {+-} 0.09, R{sub CP-} = 1.03 {+-} 0.27 {+-} 0.13, R{sub ADS} = 0.066 {+-} 0.031 {+-} 0.010, and A{sub ADS} = -0.34 {+-} 0.43 {+-} 0.16, where the first uncertainty is statistical and the second is systematic. Combining all the measurements and using a frequentist approach yields the magnitude of the ratio between the Cabibbo-suppressed and favored amplitudes, r{sub B} = 0.31 with a one (two) sigma confidence level interval of [0.24, 0.38] ([0.17, 0.43]). The value r{sub B} = 0 is excluded at the 3.3 sigma level. A similar analysis excludes values of {gamma} in the intervals [0, 7]{sup o}, [55, 111]{sup o}, and [175, 180]{sup o} ([85, 99]{sup o}) at the one (two) sigma confidence level.
Strong effects in weak nonleptonic decays
Wise, M.B.
1980-04-01T23:59:59.000Z
In this report the weak nonleptonic decays of kaons and hyperons are examined with the hope of gaining insight into a recently proposed mechanism for the ..delta..I = 1/2 rule. The effective Hamiltonian for ..delta..S = 1 weak nonleptonic decays and that for K/sup 0/-anti K/sup 0/ mixing are calculated in the six-quark model using the leading logarithmic approximation. These are used to examine the CP violation parameters of the kaon system. It is found that if Penguin-type diagrams make important contributions to K ..-->.. ..pi pi.. decay amplitudes then upcoming experiments may be able to distinguish the six-quark model for CP violation from the superweak model. The weak radiative decays of hyperons are discussed with an emphasis on what they can teach us about hyperon nonleptonic decays and the ..delta..I = 1/2 rule.
Federico Agustin Membiela; Mauricio Bellini
2007-12-18T23:59:59.000Z
Introducing a variable cosmological parameter $\\Lambda (t)$ in a geometrical manner from a 5D Riemann-flat metric, we investigate the origin and evolution of primordial magnetic fields in the early universe, when the expansion is governed by a cosmological parameter $\\Lambda (t)$ that decreases with time. Using the gravitoelectromagnetic inflationary formalism, but without the Feynman gauge, we obtain the power of spectrums for large-scale magnetic fields and the inflaton field fluctuations during inflation. A very important fact is that our formalism is {\\em naturally non-conformally invariant}.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Kong, Kyoungchui; Lee, Hye-Sung; Park, Myeonhun
2014-04-01T23:59:59.000Z
We suggest top quark decays as a venue to search for light dark force carriers. Top quark is the heaviest particle in the standard model whose decays are relatively poorly measured, allowing sufficient room for exotic decay modes from new physics. A very light (GeV scale) dark gauge boson (Z') is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the 3.6 ? deviation in the muon g-2 measurement. We present and study a possible scenario that top quark decays as t ? b W + Z's. This is the same as the dominant topmore »quark decay (t ? b W) accompanied by one or multiple dark force carriers. The Z' can be easily boosted, and it can decay into highly collimated leptons (lepton-jet) with large branching ratio. We discuss the implications for the Large Hadron Collider experiments including the analysis based on the lepton-jets.« less
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Kong, Kyoungchui [Kansas; Lee, Hye-Sung [W&M, JLAB; Park, Myeonhun [Tokyo
2014-04-01T23:59:59.000Z
We suggest top quark decays as a venue to search for light dark force carriers. Top quark is the heaviest particle in the standard model whose decays are relatively poorly measured, allowing sufficient room for exotic decay modes from new physics. A very light (GeV scale) dark gauge boson (Z') is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the 3.6 ? deviation in the muon g-2 measurement. We present and study a possible scenario that top quark decays as t ? b W + Z's. This is the same as the dominant top quark decay (t ? b W) accompanied by one or multiple dark force carriers. The Z' can be easily boosted, and it can decay into highly collimated leptons (lepton-jet) with large branching ratio. We discuss the implications for the Large Hadron Collider experiments including the analysis based on the lepton-jets.
Jackson, P.D.; /Victoria U.
2006-02-24T23:59:59.000Z
Recent results from Belle and BaBar on rare B decays involving flavor-changing neutral currents or purely leptonic final states are presented. Measurements of the CP asymmetries in B {yields} K*{gamma} and b {yields} s{gamma} are reported. Also reported are updated limits on B{sup +} {yields} K{sup +}{nu}{bar {nu}}, B{sup +} {yields} {tau}{sup +}{nu}, B{sup +} {yields} {mu}{sup +}{nu} and the recent measurement of B {yields} X{sub s}{ell}{sup +}{ell}{sup -}.
Non-standard semileptonic hyperon decays
Hsi-Ming Chang; Martin González-Alonso; Jorge Martin Camalich
2015-03-05T23:59:59.000Z
We investigate the discovery potential of semileptonic hyperon decays in terms of searches of new physics at teraelectronvolt scales. These decays are controlled by a small $SU(3)$-flavor breaking parameter that allows for systematic expansions and accurate predictions in terms of a reduced dependence on hadronic form factors. We find that muonic modes are very sensitive to non-standard scalar and tensor contributions and demonstrate that these could provide a powerful synergy with direct searches of new physics at the LHC.
Leptonic Decays of Charged Pseudoscalar Mesons - 2015
Rosner, Jonathan L; Van de Water, Ruth S
2015-01-01T23:59:59.000Z
We review the physics of purely leptonic decays of $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of the constituent quarks and a strong interaction parameter related to the overlap of the quark and antiquark wave-functions in the meson, called the decay constant $f_P$. The leptonic decay constants for $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ mesons can be obtained with controlled theoretical uncertainties and high precision from {\\it ab initio} lattice-QCD simulations. The combination of experimental leptonic decay-rate measurements and theoretical decay-constant calculations enables the determination of several elements of the CKM matrix within the standard model. These determinations are competitive with those obtained from semileptonic decays, and also complementary because they are sensitive to different quark flavor-changing currents. They can also be use...
NSAC Subcommittee Double Beta Decay
and Lawrence Berkeley National Laboratory #12;2 Decay #12;2 0 0 Decay If 0 occurs then the neutrino is a Majorana particle and the neutrino and antiparticle are not distinct. Lepton number is not conserved! #12 30 ) Experimental Resolution #12;Higgs Boson, Majorana Mass and Lepton Number Conservation #12;LVD
Particle decay in false vacuum
Gorsky, A.; Voloshin, M. B. [William I. Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Institute of Theoretical and Experimental Physics, Moscow, 117259 (Russian Federation)
2006-01-15T23:59:59.000Z
We revisit the problem of decay of a metastable vacuum induced by the presence of a particle. For the bosons of the 'master field' the problem is solved in any number of dimensions in terms of the spontaneous decay rate of the false vacuum, while for a fermion we find a closed expression for the decay rate in (1+1) dimensions. It is shown that in the (1+1) dimensional case an infrared problem of one-loop correction to the decay rate of a boson is resolved due to a cancellation between soft modes of the field. We also find the boson decay rate in the 'sine-Gordon staircase' model in the limits of strong and weak coupling.
Particle decay in false vacuum
A. Gorsky; M. B. Voloshin
2005-11-08T23:59:59.000Z
We revisit the problem of decay of a metastable vacuum induced by the presence of a particle. For the bosons of the `master field' the problem is solved in any number of dimensions in terms of the spontaneous decay rate of the false vacuum, while for a fermion we find a closed expression for the decay rate in (1+1) dimensions. It is shown that in the (1+1) dimensional case an infrared problem of one-loop correction to the decay rate of a boson is resolved due to a cancellation between soft modes of the field. We also find the boson decay rate in the `sine-Gordon staircase' model in the limits of strong and weak coupling.
A. M. Sukhovoj; V. A. Khitrov
2009-06-18T23:59:59.000Z
Comparison between potential possibilities and inevitable systematic errors of one- and two-step reactions for obtaining of maximum reliable data on level density and radiative strength functions after decay of excited levels of complicated nuclei has been performed. It was shown that the use for this aim of two-step reactions instead of one-step reactions provides for potential possibility to decrease systematical errors of mentioned nuclear parameters, as minimum, by several times.
Proton Decay and the Planck Scale
Larson, Daniel T.
2009-01-01T23:59:59.000Z
LBNL- 56556 PROTON DECAY AND THE PLANCK SCALE DANIEL T.ph/0410035v1 2 Oct 2004 PROTON DECAY AND THE PLANCK SCALE ?without grand uni?cation, proton decay can be a powerful
Search for neutrinoless decays of the ? lepton
Baringer, Philip S.
1990-02-01T23:59:59.000Z
We have searched for neutrinoless ? decays into three charged particles. Evidence of such decays would demonstrate nonconservation of lepton flavor and, in some cases, lepton number. We see no signal for any such neutrinoless ? decays and set upper...
LHC prospects for minimal decaying dark matter
Arcadi, Giorgio; Covi, Laura; Dradi, Federico, E-mail: giorgio.arcadi@theorie.physik.uni-goettingen.de, E-mail: laura.covi@theorie.physik.uni-goettingen.de, E-mail: federico.dradi@theorie.physik.uni-goettingen.de [Institute for Theoretical Physics, Georg-August University Göttingen, Friedrich-Hund-Platz 1, Göttingen, D-37077 Germany (Germany)
2014-10-01T23:59:59.000Z
We study the possible signals at LHC of the minimal models of decaying dark matter. Those models are characterized by the fact that DM interacts with SM particles through renormalizable coupling with an additional heavier charged state. Such interaction allows to produce a substantial abundance of DM in the early Universe via the decay of the charged heavy state, either in- or out-of-equilibrium. Moreover additional couplings of the charged particle open up decay channels for the DM, which can nevertheless be sufficiently long-lived to be a good DM candidate and within reach of future Indirect Detection observations. We compare the cosmologically favored parameter regions to the LHC discovery reach and discuss the possibility of simultaneous detection of DM decay in Indirect Detection.
Neutrinoless Double Beta Decay Constraints
Hiroaki Sugiyama
2003-07-25T23:59:59.000Z
A brief overview is given of theoretical analyses with neutrinoless double beta decay experiments. Theoretical bounds on the ``observable'', _betabeta, are presented. By using experimental bounds on _betabeta, allowed regions are obtained on the m_l-cos{2theta_12} plane, where m_l stands for the lightest neutrino mass. It is shown that Majorana neutrinos can be excluded by combining possible results of future neutrinoless double beta decay and {}^3H beta decay experiments. A possibility to constrain one of two Majorana phases is discussed also.
E. El aaoud
1998-01-08T23:59:59.000Z
Motivated by the experimental measurement of the decay rate, $\\Gamma$, and the longitudinal polarization, $P_L$, in the Cabibbo favored decay $D_s^+\\to \\phi {\\rho}^{+}$, we have studied theoretical prediction within the context of factorization approximation invoking several form factors models. We were able to obtain agreement with experiment for both $\\Gamma$ and $P_L$ by using experimentally measured values of the form factors $A_1^{D_s\\phi}(0)$, $A_2^{D_s\\phi}(0)$ and $V^{D_s\\phi}(0)$ in the semi-leptonic decay $D_s^+\\to \\phi l^{+}\
Computer code for double beta decay QRPA based calculations
Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University
. The Enriched Xenon Observatory for neutrinoless double beta decay (EXO) will search for the rare decays
Recent Results on Semileptonic Decays at Babar
Serrano, Justine; /Orsay, LAL
2011-11-07T23:59:59.000Z
Some recent BABAR results on semileptonic decays are presented. They focus on the determination of the CKM matrix elements |V{sub ub}| and |V{sub cb}| in inclusive and exclusive b {yields} u{ell}v and b {yields} c{ell}v decays, and on form factors measurement in exclusive c {yields} s{ell}v decays. Semileptonic decays play a crucial role in the determination of the unitarity triangle parameters: decays of the b quark give access to the CKM matrix elements |V{sub ub}| and |V{sub cb}|, while charm decays provide a way to validate lattice QCD computations through form factors measurements. Such calculations provide theoretical inputs that are used, especially, in the b sector. A lot of new results have been obtained by the BABAR collaboration during the last years, thanks to the large b{bar b} and c{bar c} production cross-sections and to the large recorded statistics. Some of these measurements are presented here.
Moretto, L.G.; Wozniak, G.J.
1988-11-01T23:59:59.000Z
The formation of hot compound nuclei in intermediate-energy heavy ion reactions is discussed. The statistical decay of such compound nuclei is responsible for the abundant emission of complex fragments and high energy gamma rays. 43 refs., 23 figs.
Decoherence delays false vacuum decay
Thomas C. Bachlechner
2013-04-17T23:59:59.000Z
We show that gravitational interactions between massless thermal modes and a nucleating Coleman-de Luccia bubble may lead to efficient decoherence and strongly suppress metastable vacuum decay for bubbles that are small compared to the Hubble radius. The vacuum decay rate including gravity and thermal photon interactions has the exponential scaling $\\Gamma\\sim\\Gamma_{CDL}^{2}$, where $\\Gamma_{CDL}$ is the Coleman-de Luccia decay rate neglecting photon interactions. For the lowest metastable initial state an efficient quantum Zeno effect occurs due to thermal radiation of temperatures as low as the de Sitter temperature. This strong decoherence effect is a consequence of gravitational interactions with light external mode. We argue that efficient decoherence does not occur for the case of Hawking-Moss decay. This observation is consistent with requirements set by Poincare recurrence in de Sitter space.
Ishkhanyan, A M
2015-01-01T23:59:59.000Z
We discuss the possibility of non-exponential Auger decay of atoms irradiated by X-ray photons. This effect can occur at times, which are greater than the lifetime of a system under consideration. The mechanism for non-exponential depletion of an initial quasi-stationary state is the cutting of the electron energy spectrum of final continuous states at small energies. Then the Auger decay amplitude obeys power-law dependence on long observation times.
Measurement of the CP-violation parameter of B0 mixing and decay with p anti-p ---> mu mu X data
Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Agelou, M.; Aguilo, E.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; /Buenos Aires U. /Rio de Janeiro,
2006-09-01T23:59:59.000Z
The authors measure the dimuon charge asymmetry A in p{bar p} collisions at a center of mass energy {radical}s 1960 GeV. The data was recorded with the D0 detector and corresponds to an integrated luminosity of approximately 1.0 fb{sup -1}. Assuming that the asymmetry A is due to asymmetric B{sup 0} {leftrightarrow} {bar B}{sup 0} mixing and decay, they extract the CP-violation parameter of B{sup 0} mixing and decay: R({epsilon}{sub B{sup 0}}/1) + |{epsilon}{sub B{sup 0}}|{sup 2} = A{sub B{sup 0}}/4 = -0.0023 {+-} 0.0011(stat) {+-} 0.0008(syst). A{sub B{sup 0}} is the dimuon charge asymmetry from decays of B{sup 0}{bar B}{sup 0} pairs. The general case, with CP violation in both B{sup 0} and B{sub s}{sup 0} systems, is also considered. Finally they obtain the forward-backward asymmetry that quantifies the tendency of {mu}{sup +} to go in the proton direction and {mu}{sup -} to go in the anti-proton direction. The results are consistent with the standard model and constrain new physics.
Signature of nonexponential nuclear decay
A Ray; A K Sikdar; A De
2015-03-18T23:59:59.000Z
Precision tests of decay law of radioactive nuclei have not so far found any deviation from the exponential decay law at early time, as predicted by quantum mechanics. In this paper, we show that the quantum decoherence time (i.e. the timescale of nonexponential decay) of the quasifission or fission process should be of the order of attosecond considering the atom of the fissioning nucleus as a quantum detector. Hence, the observed decay timescale of the quasifission or fission process of even highly excited (EX greater than 50 MeV) transuranium and uraniumlike complexes should be rather long (of the order of attosecond) in spite of their very fast exponential decay timescale (of the order of zeptosecond) as measured by the nuclear techniques. Recent controversy regarding the observation of very long (of the order of attosecond ) and very short (of the order of zeptosecond ) quasifission or fission timescales for similar systems at similar excitation energies as obtained by direct techniques (crystal blocking, X ray fission fragment) and nuclear techniques could be interpreted as evidence for nonexponential decays in nuclear systems
Predicting neutrinoless double beta decay
Hirsch, M.; Villanova del Moral, A.; Valle, J.W.F. [AHEP Group, Instituto de Fisica Corpuscular - C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apt 22085, E-46071 Valencia (Spain); Ma, Ernest [Physics Department, University of California, Riverside, California 92521 (United States); Institute for Particle Physics Phenomenology, University of Durham, Durham, DH1 3LE (United Kingdom)
2005-11-01T23:59:59.000Z
We give predictions for the neutrinoless double beta decay rate in a simple variant of the A{sub 4} family symmetry model. We show that there is a lower bound for the {beta}{beta}{sub 0{nu}} amplitude even in the case of normal hierarchical neutrino masses, corresponding to an effective mass parameter vertical bar m{sub ee} vertical bar {>=}0.17{radical}({delta}m{sub ATM}{sup 2}). This result holds both for the CP conserving and CP violating cases. In the latter case we show explicitly that the lower bound on vertical bar m{sub ee} vertical bar is sensitive to the value of the Majorana phase. We conclude therefore that in our scheme, {beta}{beta}{sub 0{nu}} may be accessible to the next generation of high sensitivity experiments.
Observation of parity violation in the Omega- ---> Lambda K- decay
Lu, L.C.; /Virginia U.; Burnstein, R.A.; Chakravorty, A.; Chen, Y.C.; Choong, W.-S.; Clark, K.; Dukes, E.C.; Durandet, C.; Felix, J.; Fu, Y.; Gidal, G.; Gustafson, H.R.; Holmstrom, T.; Huang, M.; James, C.; Jenkins, C.M.; Jones, T.D.; Kaplan, D.M.; Longo, M.J.; Luebke, W.; Luk, K.-B.; /Taiwan, Inst. Phys. /UC, Berkeley /Fermilab /Guanajuato U./IIT, Chicago /Lausanne U. /LBL, Berkeley /Michigan U. /South Alabama U. /Virginia U.; ,
2005-05-01T23:59:59.000Z
The {alpha} decay parameter in the process {Omega}{sup -} {yields} {Lambda}K{sup -} has been measured from a sample of 4.50 million unpolarized {Omega}{sup -} decays recorded by the HyperCP (E871) experiment at Fermilab and found to be [1.78 {+-} 0.19(stat) {+-} 0.16(syst)] x 10{sup -2}. This is the first unambiguous evidence for a nonzero {alpha} decay parameter, and hence parity violation, in the {Omega}{sup -} {Lambda}K{sup -} decay.
Signature of nonexponential nuclear decay
Ray, A; De, A
2015-01-01T23:59:59.000Z
Precision tests of decay law of radioactive nuclei have not so far found any deviation from the exponential decay law at early time, as predicted by quantum mechanics. In this paper, we show that the quantum decoherence time (i.e. the timescale of nonexponential decay) of the quasifission or fission process should be of the order of attosecond considering the atom of the fissioning nucleus as a quantum detector. Hence, the observed decay timescale of the quasifission or fission process of even highly excited (EX greater than 50 MeV) transuranium and uraniumlike complexes should be rather long (of the order of attosecond) in spite of their very fast exponential decay timescale (of the order of zeptosecond) as measured by the nuclear techniques. Recent controversy regarding the observation of very long (of the order of attosecond ) and very short (of the order of zeptosecond ) quasifission or fission timescales for similar systems at similar excitation energies as obtained by direct techniques (crystal blocking...
Proton decay in the super-world
Raby, S.
1986-01-01T23:59:59.000Z
Predictions are elaborated for nucleon decay in supersymmetric grand unified theories (SUSY GUT's). A minimal SU/sub 5/ SUSY GUT is described, as well as SU/sub 5/ breaking. The low energy theory and breaking of supersymmetry are discussed. It is concluded that nucleon decay in SUSY GUT's would be dominated by p ..-->.. K/sup +/anti nu/sub ..mu../ and n ..-->.. K/sup 0/anti nu/sub ..mu../. There are ranges in parameter space for which other decay modes may be significant or may even dominate, it is found. It is noted that minimal SUSY GUT's typically predict a value of sin/sup 2/theta/sub w/ of order .233. 20 refs., 7 figs. (LEW)
Decaying and kicked turbulence in a shell model
Jan-Otto Hooghoudt; Detlef Lohse; Federico Toschi
2000-12-06T23:59:59.000Z
Decaying and periodically kicked turbulence are analyzed within the GOY shell model, to allow for sufficiently large scaling regimes. Energy is transfered towards the small scales in intermittent bursts. Nevertheless, mean field arguments are sufficient to account for the ensemble averaged energy decay E(t) \\~t^{-2} or the parameter dependences for the ensemble averaged total energy in the kicked case. Within numerical precision, the inertial subrange intermittency remains the same, whether the system is forced or decaying.
Neutrinoless Double Beta Decay Experiments
Garfagnini, Alberto
2014-01-01T23:59:59.000Z
Neutrinoless double beta decay is the only process known so far able to test the neutrino intrinsic nature: its experimental observation would imply that the lepton number is violated by two units and prove that neutrinos have a Majorana mass components, being their own anti-particle. While several experiments searching for such a rare decay have been performed in the past, a new generation of experiments using different isotopes and techniques have recently released their results or are taking data and will provide new limits, should no signal be observed, in the next few years to come. The present contribution reviews the latest public results on double beta decay searches and gives an overview on the expected sensitivities of the experiments in construction which will be able to set stronger limits in the near future.
Neutrinoless Double Beta Decay Experiments
Alberto Garfagnini
2014-08-11T23:59:59.000Z
Neutrinoless double beta decay is the only process known so far able to test the neutrino intrinsic nature: its experimental observation would imply that the lepton number is violated by two units and prove that neutrinos have a Majorana mass components, being their own anti-particle. While several experiments searching for such a rare decay have been performed in the past, a new generation of experiments using different isotopes and techniques have recently released their results or are taking data and will provide new limits, should no signal be observed, in the next few years to come. The present contribution reviews the latest public results on double beta decay searches and gives an overview on the expected sensitivities of the experiments in construction which will be able to set stronger limits in the near future.
Thermodynamics of decaying vacuum cosmologies
Lima, J.A. [Physics Department, Brown University, Providence, Rhode Island 02912 (United States)] [Physics Department, Brown University, Providence, Rhode Island 02912 (United States); [Departamento de Fisica Teorica e Experimental, Universidade Federal do Rio Grande do Norte, 59072-970, Natal, RN (Brazil)
1996-08-01T23:59:59.000Z
The thermodynamic behavior of decaying vacuum cosmologies is investigated within a manifestly covariant formulation. Such a process corresponds to a continuous, irreversible energy flow from the vacuum component to the created matter constituents. It is shown that if the specific entropy per particle remains constant during the process, the equilibrium relations are preserved. In particular, if the vacuum decays into photons, the energy density {rho} and average number density of photons {ital n} scale with the temperature as {rho}{approximately}{ital T}{sup 4} and {ital n}{approximately}{ital T}{sup 3}. The temperature law is determined and a generalized Planckian-type form of the spectrum, which is preserved in the course of the evolution, is also proposed. Some consequences of these results for decaying vacuum FRW-type cosmologies as well as for models with {open_quote}{open_quote}adiabatic{close_quote}{close_quote} photon creation are discussed. {copyright} {ital 1996 The American Physical Society.}
Measurement of B0(s) mixing parameters from the flavor-tagged decay B0(s) ---> J/psi phi
Abazov, V.M.; /Dubna, JINR; Abbott, B.; /Oklahoma U.; Abolins, M.; /Michigan State U.; Acharya, B.S.; /Tata Inst.; Adams, M.; /Illinois U., Chicago; Adams, T.; /Florida State U.; Aguilo, E.; /Simon Fraser U.; Ahn, S.H.; /Korea U., KODEL; Ahsan, M.; /Kansas State U.; Alexeev, G.D.; /Dubna, JINR; Alkhazov, G.; /St. Petersburg, INP /Michigan U.
2008-02-01T23:59:59.000Z
From an analysis of the flavor-tagged decay B{sub s}{sup 0} {yields} J/{psi}{phi} they obtain the width difference between the B{sub s}{sup 0} light and heavy mass eigenstates, {Delta}{Lambda}{sub s} {triple_bond} {Lambda}{sub L} - {Lambda}{sub H} = 0.19 {+-} 0.07(stat){sub -0.01}{sup +0.02}(syst) ps{sup -1}, and the CP-violating phase, {phi}{sub s} = -0.57{sub -0.30}{sup +0.24}(stat){sub -0.02}{sup +0.07}(syst). The allowed 90% C.L. intervals of {Delta}{Lambda}{sub s} and {phi}{sub s} are 0.06 < {Delta}{Lambda}{sub s} < 0.30 ps{sup -1} and -1.20 < {phi}{sub s} < 0.06, respectively. The data sample corresponds to an integrated luminosity of 2.8 fb{sup -1} accumulated with the D0 detector at the Fermilab Tevatron collider.
Time evolution of cascade decay
Daniel Boyanovsky; Louis Lello
2014-06-25T23:59:59.000Z
We study non-perturbatively the time evolution of cascade decay for generic fields $\\pi \\rightarrow \\phi_1\\phi_2\\rightarrow \\phi_2\\chi_1\\chi_2$ and obtain the time dependence of amplitudes and populations for the resonant and final states. We analyze in detail the different time scales and the manifestation of unitary time evolution in the dynamics of production and decay of resonant intermediate and final states. The probability of occupation (population) "flows" as a function of time from the initial to the final states. When the decay width of the parent particle $\\Gamma_\\pi$ is much larger than that of the intermediate resonant state $\\Gamma_{\\phi_1}$ there is a "bottleneck" in the flow, the population of resonant states builds up to a maximum at $t^* = \\ln[\\Gamma_\\pi/\\Gamma_{\\phi_1}]/(\\Gamma_\\pi-\\Gamma_{\\phi_1})$ nearly saturating unitarity and decays to the final state on the longer time scale $1/\\Gamma_{\\phi_1}$. As a consequence of the wide separation of time scales in this case the cascade decay can be interpreted as evolving sequentially $\\pi \\rightarrow \\phi_1\\phi_2; ~ \\phi_1\\phi_2\\rightarrow \\phi_2\\chi_1\\chi_2$. In the opposite limit the population of resonances ($\\phi_1$) does not build up substantially and the cascade decay proceeds almost directly from the initial parent to the final state without resulting in a large amplitude of the resonant state. An alternative but equivalent non-perturbative method useful in cosmology is presented. Possible phenomenological implications for heavy sterile neutrinos as resonant states and consequences of quantum entanglement and correlations in the final state are discussed.
Symmetry violations in nuclear and neutron $?$ decay
K. K. Vos; H. W. Wilschut; R. G. E. Timmermans
2015-09-14T23:59:59.000Z
The role of $\\beta$ decay as a low-energy probe of physics beyond the Standard Model is reviewed. Traditional searches for deviations from the Standard Model structure of the weak interaction in $\\beta$ decay are discussed in the light of constraints from the LHC and the neutrino mass. Limits on the violation of time-reversal symmetry in $\\beta$ decay are compared to the strong constraints from electric dipole moments. Novel searches for Lorentz symmetry breaking in the weak interaction in $\\beta$ decay are also included, where we discuss the unique sensitivity of $\\beta$ decay to test Lorentz invariance. We end with a roadmap for future $\\beta$-decay experiments.
What can we learn from neutrinoless double beta decay experiments?
Bahcall, John N.
2009-01-01T23:59:59.000Z
Limits From Neutrinoless Double-Beta Decay (Rev. ),” ina next generation neutrinoless double beta decay search andPARTICLES? NO NEUTRINOLESS DOUBLE BETA DECAY AND INVERTED
Neutrinoless double beta decay in seesaw models
Mattias Blennow; Enrique Fernandez-Martinez; Jacobo Lopez-Pavon; Javier Menendez
2014-05-12T23:59:59.000Z
We study the general phenomenology of neutrinoless double beta decay in seesaw models. In particular, we focus on the dependence of the neutrinoless double beta decay rate on the mass of the extra states introduced to account for the Majorana masses of light neutrinos. For this purpose, we compute the nuclear matrix elements as functions of the mass of the mediating fermions and estimate the associated uncertainties. We then discuss what can be inferred on the seesaw model parameters in the different mass regimes and clarify how the contribution of the light neutrinos should always be taken into account when deriving bounds on the extra parameters. Conversely, the extra states can also have a significant impact, cancelling the Standard Model neutrino contribution for masses lighter than the nuclear scale and leading to vanishing neutrinoless double beta decay amplitudes even if neutrinos are Majorana particles. We also discuss how seesaw models could reconcile large rates of neutrinoless double beta decay with more stringent cosmological bounds on neutrino masses.
Search for New Physics in Rare Top Decays
Pratishruti Saha
2014-11-27T23:59:59.000Z
Top physics provides a fertile ground for new-physics searches. At present, most top observables appear to be in good agreement with the respective Standard Model predictions. However, in the case of decay modes that are suppressed in the Standard Model, new-physics contributions of comparable magnitude may exist and yet go unnoticed because their impact on the total decay width is small. Hence it is interesting to probe rare top decays. This analysis focuses on the decay $t \\to b \\bar b c$. Useful observables are identified and prospects for measuring new-physics parameters are examined.
PyDecay/GraphPhys: A Unified Language and Storage System for Particle Decay Process Descriptions
Dunietz, Jesse N.; /MIT /SLAC
2011-06-22T23:59:59.000Z
To ease the tasks of Monte Carlo (MC) simulation and event reconstruction (i.e. inferring particle-decay events from experimental data) for long-term BaBar data preservation and analysis, the following software components have been designed: a language ('GraphPhys') for specifying decay processes, common to both simulation and data analysis, allowing arbitrary parameters on particles, decays, and entire processes; an automated visualization tool to show graphically what decays have been specified; and a searchable database storage mechanism for decay specifications. Unlike HepML, a proposed XML standard for HEP metadata, the specification language is designed not for data interchange between computer systems, but rather for direct manipulation by human beings as well as computers. The components are interoperable: the information parsed from files in the specification language can easily be rendered as an image by the visualization package, and conversion between decay representations was implemented. Several proof-of-concept command-line tools were built based on this framework. Applications include building easier and more efficient interfaces to existing analysis tools for current projects (e.g. BaBar/BESII), providing a framework for analyses in future experimental settings (e.g. LHC/SuperB), and outreach programs that involve giving students access to BaBar data and analysis tools to give them a hands-on feel for scientific analysis.
Constraining neutrinoless double beta decay
L. Dorame; D. Meloni; S. Morisi; E. Peinado; J. W. F. Valle
2011-11-23T23:59:59.000Z
A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). We show how these theories may constrain the absolute scale of neutrino mass, leading in most of the cases to a lower bound on the neutrinoless double beta decay effective amplitude.
Farrington, S.M.; /Liverpool U.
2006-01-01T23:59:59.000Z
The confidence level limits of the CDF and D0 searches for the B{sub s}{sup 0}, B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -}{phi} rare decays are presented.
Hyman, BC; Iacob, VE; Azhari, A.; Gagliardi, Carl A.; Hardy, John C.; Mayes, VE; Neilson, RG; Sanchez-Vega, M.; Tang, X.; Trache, L.; Tribble, Robert E.
2003-01-01T23:59:59.000Z
We report a study of the beta decay of Ga-62, whose dominant branch is a superallowed 0(+)-->0(+) transition to the ground state of Zn-62. We find the total half-life to be 115.84+/-0.25 ms. This is the first time that the Ga-62 half-life has been...
Radiative Penguin Decays at the B Factories
Cuhadar-Donszelmann, T.; /British Columbia U.
2007-03-05T23:59:59.000Z
Recent results from the B-Factories on radiative decays such as b {yields} s(d){gamma}, b {yields} s{ell}{ell} and leptonic decay B{sup 0} {yields} {tau}{sup +}{tau}{sup -} are reviewed.
Causes and Control of Wood Decay,
1 Causes and Control of Wood Decay, Degradation & Stain #12;2 Contents Moisture .................................................................................3 Wood Degradation: Causes and Control..............................4 Weathering......................................................................................................4 Naturally Decay-resistant Species...........................................................5 Wood
Proton decay matrix elements from lattice QCD
Cooney, Paul
2010-01-01T23:59:59.000Z
We present results for the matrix elements relevant for proton decay in Grand Unified Theories (GUTs), using two methods. In the indirect method, we rely on an effective field theory description of proton decay, where ...
Imperfect World of $??$-decay Nuclear Data Sets?
B. Pritychenko
2015-03-11T23:59:59.000Z
The precision of double-beta ($\\beta\\beta$) decay experimental half-lives and their uncertainties is reevaluated. A complementary analysis of the decay uncertainties indicates deficiencies due to small size of statistical samples, and incomplete collection of experimental information. Further experimental and theoretical efforts would lead toward more precise values of $\\beta\\beta$-decay half-lives and nuclear matrix elements.
Double beta decay: experiments and theory review
A. Nucciotti
2007-07-28T23:59:59.000Z
Neutrinoless double beta decay is one of the most powerful tools to set the neutrino mass absolute scale and establish whether the neutrino is a Majorana particle. After a summary of the neutrinoless double beta decay phenomenology, the present status of the experimental search for this rare decay is reported and the prospects for next generation experiments are reviewed.
Artuso, M.; Asner, D.M.; Ball, P.; Baracchini, E.; Bell, G.; Beneke, M.; Berryhill, J.; Bevan, A.; Bigi, I.I.; Blanke, M.; Bobeth, Ch.; Bona, M.; Borzumati, F.; Browder, T.; Buanes, T.; Buchalla, G.; Buchmuller, O.; Buras, A.J.; Burdin, S.; Cassel, D.G.; Cavanaugh, R.; /Syracuse U. /Carleton U. /Durham U., IPPP /Rome U. /INFN, Rome /Karlsruhe U. /RWTH Aachen U. /Fermilab /Queen Mary, U. of London /Notre Dame U. /Munich, Tech. U. /Munich, Max Planck Inst. /Dortmund U. /Annecy, LAPP /ICTP, Trieste /Taiwan, Natl. Central U. /Hawaii U. /Bergen U. /Munich U. /CERN /Liverpool U.
2008-03-07T23:59:59.000Z
The present report documents the results of Working Group 2: B, D and K decays, of the workshop on Flavor in the Era of the LHC, held at CERN from November 2005 through March 2007. With the advent of the LHC, we will be able to probe New Physics (NP) up to energy scales almost one order of magnitude larger than it has been possible with present accelerator facilities. While direct detection of new particles will be the main avenue to establish the presence of NP at the LHC, indirect searches will provide precious complementary information, since most probably it will not be possible to measure the full spectrum of new particles and their couplings through direct production. In particular, precision measurements and computations in the realm of flavor physics are expected to play a key role in constraining the unknown parameters of the Lagrangian of any NP model emerging from direct searches at the LHC. The aim of Working Group 2 was twofold: on one hand, to provide a coherent, up-to-date picture of the status of flavor physics before the start of the LHC; on the other hand, to initiate activities on the path towards integrating information on NP from high-p{sub T} and flavor data. This report is organized as follows. In Sec. 1, we give an overview of NP models, focusing on a few examples that have been discussed in some detail during the workshop, with a short description of the available computational tools for flavor observables in NP models. Sec. 2 contains a concise discussion of the main theoretical problem in flavor physics: the evaluation of the relevant hadronic matrix elements for weak decays. Sec. 3 contains a detailed discussion of NP effects in a set of flavor observables that we identified as 'benchmark channels' for NP searches. The experimental prospects for flavor physics at future facilities are discussed in Sec. 4. Finally, Sec. 5 contains some assessments on the work done at the workshop and the prospects for future developments.
Rare meson decays into very light neutralinos
Dreiner, H. K.; Grab, S.; Koschade, Daniel; Kraemer, M.; O'Leary, Ben; Langenfeld, Ulrich [Bethe Center for Theoretical Physics and Physikalisches Institut der Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Institut fuer Theoretische Physik, RWTH Aachen University, 52056 Aachen, Germany and Centre for Research in String Theory, Department of Physics, Queen Mary, University of London, E1 4NS London (United Kingdom); Institut fuer Theoretische Physik, RWTH Aachen University, 52056 Aachen (Germany); DESY, Platanenallee 6, D-15738 Zeuthen (Germany)
2009-08-01T23:59:59.000Z
We investigate the bounds on the mass of the lightest neutralino from rare meson decays within the minimal supersymmetric standard model (MSSM) with and without minimal flavor violation. We present explicit formulas for the two-body decays of mesons into light neutralinos and perform the first complete calculation of the loop-induced decays of kaons to pions and light neutralinos and B mesons to kaons and light neutralinos. We find that the supersymmetric branching ratios are strongly suppressed within the MSSM with minimal flavor violation, and that no bounds on the neutralino mass can be inferred from experimental data, i.e., a massless neutralino is allowed. The branching ratios for kaon and B meson decays into light neutralinos may, however, be enhanced when one allows for nonminimal flavor violation. We find new constraints on the MSSM parameter space for such scenarios and discuss prospects for future kaon and B meson experiments. Finally, we comment on the search for light neutralinos in monojet signatures at the Tevatron and at the LHC.
Neutrinoless Double Beta Decay in Particle Physics
Werner Rodejohann
2010-11-22T23:59:59.000Z
Neutrinoless double beta decay is a process of fundamental importance for particle physics. It can be mediated by light massive Majorana neutrinos (standard interpretation) or by something else (non-standard interpretations). We review its dependence on the neutrino parameters, its complementarity to other observables sensitive to neutrino mass, and emphasize its ability to distinguish different neutrino mass models. Then we discuss mechanisms different from light Majorana neutrino exchange, and show what can be learned from those and how they could be tested.
Neutralino dark matter from heavy axino decay
Choi, Ki-Young [Departamento de Fisica Teorica C-XI, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Instituto de Fisica Teorica UAM/CSIC, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Kim, Jihn E. [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Lee, Hyun Min [Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); Seto, Osamu [Instituto de Fisica Teorica UAM/CSIC, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)
2008-06-15T23:59:59.000Z
We consider cosmological consequences of a heavy axino, decaying to the neutralino in R-parity conserving models. The importance and influence of the axino decay on the resultant abundance of neutralino dark matter depends on the lifetime and the energy density of axino. For a high reheating temperature after inflation, copiously produced axinos dominate the energy density of the universe, and its decay produces a large amount of entropy. As a bonus, we obtain that the upper bound on the reheating temperature after inflation via gravitino decay can be moderated, because the entropy production by the axino decay more or less dilutes the gravitinos.
FDCSUSYDecay: A MSSM Decay package
Wei Qi; Jian-Xiong Wang
2006-12-01T23:59:59.000Z
FDCSUSYDecay is a FORTRAN program package generated by FDC (Feynman Diagram Calculation) system fully automatically. It is dedicated to calculate at tree-level all the possible 2-body decays of SUSY and Higgs particles in the Minimal Supersymmetric extension of the Standard Model (MSSM). The format of its output files complies with SUSY Les Houches Accord and can be easily imported by other packages.
F. Cardone; R. Mignani; A. Petrucci
2007-10-26T23:59:59.000Z
We show that cavitation of a solution of thorium-228 in water induces its transformation at a rate 10000 times faster than the natural radioactive decay would do. This result agrees with the alteration of the secular equilibrium of thorium-234 obtained by a Russian team via explosion of titanium foils in water and solutions. These evidences further support some preliminary clues for the possibility of piezonuclear reactions (namely nuclear reactions induced by pressure waves) obtained in the last ten years.
Heavy-to-light decays on the lattice
Müller, Eike Hermann
2009-01-01T23:59:59.000Z
Precise predictions of hadronic matrix elements in heavy meson decays are important to constrain the fundamental parameters in the Standard Model of particle physics. The CKM matrix element Vub can be extracted from ...
JUNO and Neutrinoless Double Beta Decay
Shao-Feng Ge; Werner Rodejohann
2015-07-20T23:59:59.000Z
We study the impact of the precision determination of oscillation parameters in the JUNO experiment on half-life predictions for neutrinoless double beta decay. We show that the solar neutrino mixing angle can be measured by JUNO with below 1% uncertainty. This implies in particular that the minimal value of the effective mass in the inverted mass ordering will be known essentially without uncertainty. We demonstrate that this reduces the range of half-life predictions in order to test this value by a factor of two. The remaining uncertainty is caused by nuclear matrix elements. This has important consequences for future double beta decay experiments that aim at ruling out the inverted mass ordering or the Majorana nature of neutrinos.
JUNO and Neutrinoless Double Beta Decay
Ge, Shao-Feng
2015-01-01T23:59:59.000Z
We study the impact of the precision determination of oscillation parameters in the JUNO experiment on half-life predictions for neutrinoless double beta decay. We show that the solar neutrino mixing angle can be measured by JUNO with below 1% uncertainty. This implies in particular that the minimal value of the effective mass in the inverted mass ordering will be known essentially without uncertainty. We demonstrate that this reduces the range of half-life predictions in order to test this value by a factor of two. The remaining uncertainty is caused by nuclear matrix elements. This has important consequences for future double beta decay experiments that aim at ruling out the inverted mass ordering or the Majorana nature of neutrinos.
Extra dimensions, orthopositronium decay, and stellar cooling
Alexander Friedland; Maurizio Giannotti
2007-09-14T23:59:59.000Z
In a class of extra dimensional models with a warped metric and a single brane the photon can be localized on the brane by gravity only. An intriguing feature of these models is the possibility of the photon escaping into the extra dimensions. The search for this effect has motivated the present round of precision orthopositronium decay experiments. We point out that in this framework a photon in plasma should be metastable. We consider the astrophysical consequences of this observation, in particular, what it implies for the plasmon decay rate in globular cluster stars and for the core-collapse supernova cooling rate. The resulting bounds on the model parameter exceed the possible reach of orthopositronium experiments by many orders of magnitude.
Sterile Neutrinos in Neutrinoless Double Beta Decay: An Update
Faessler, Amand; Kovalenko, Sergey; Simkovic, Fedor
2014-01-01T23:59:59.000Z
We revisit the mechanism of neutrinoless double beta (NLDBD) decay mediated by the exchange with the heavy Majorana neutrino N of arbitrary mass mN, slightly mixed with the electron neutrino. By assuming the dominance of this mechanism we update the well known NLDBD-decay exclusion plot in the mass-mixing angle plane taking into account recent progress in calculation of nuclear matrix elements within quasiparticle random phase approximation and improved experimental bounds on the NLDBD-decay half-life of Ge-76 and Xe-136. We also consider the known formula approximating the mN dependence of the NLDBD-decay nuclear matrix element in a simple explicit form. We analyze its accuracy and specify the corresponding parameters allowing one to easily calculate the NLDBD-decay half-life for arbitrary mN for all the experimentally interesting isotopes without resorting to real nuclear structure calculations.
Decays of Fourth Generation Bound States
V. F. Dmitriev; V. V. Flambaum
2012-08-28T23:59:59.000Z
We consider the decay modes of the heavy $q^\\prime\\bar{q^\\prime}$ bound states originating from Higgs boson exchange between quark -- anti-quark pair. In case of a small coupling between the fourth and lower generation the main decay mode is $q^\\prime\\bar{q^\\prime}$ annihilation. We show that for a vector state the dominant decay modes are Higgs-gamma and Higgs-Z decays, while for a pseudoscalar state the strong two-gluon decay mode dominates. The bound states are very narrow. The ratio of the total width to the binding energy is less than 1% if we are not extremely close to the critical quark mass where the binding energy is very small. The discussed decay modes exist for any fermion-antifermion bound states including heavy leptons and heavy neutrinos if their masses are high enough to form a bound state due to attractive Higgs boson exchange potential.
Power Spectrum Analyses of Nuclear Decay Rates
Javorsek, D; Lasenby, R N; Lasenby, A N; Buncher, J B; Fischbach, E; Gruenwald, J T; Hoft, A W; Horan, T J; Jenkins, J H; Kerford, J L; Lee, R H; Longman, A; Mattes, J J; Morreale, B L; Morris, D B; Mudry, R N; Newport, J R; O'Keefe, D; Petrelli, M A; Silver, M A; Stewart, C A; Terry, B; 10.1016/j.astropartphys.2010.06.011
2010-01-01T23:59:59.000Z
We provide the results from a spectral analysis of nuclear decay data displaying annually varying periodic fluctuations. The analyzed data were obtained from three distinct data sets: 32Si and 36Cl decays reported by an experiment performed at the Brookhaven National Laboratory (BNL), 56Mn decay reported by the Children's Nutrition Research Center (CNRC), but also performed at BNL, and 226Ra decay reported by an experiment performed at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. All three data sets exhibit the same primary frequency mode consisting of an annual period. Additional spectral comparisons of the data to local ambient temperature, atmospheric pressure, relative humidity, Earth-Sun distance, and their reciprocals were performed. No common phases were found between the factors investigated and those exhibited by the nuclear decay data. This suggests that either a combination of factors was responsible, or that, if it was a single factor, its effects on the decay rate experiments are n...
Kong, Kyoungchul; Lee, Hye-Sung; Park, Myeonghun
2014-04-01T23:59:59.000Z
We suggest top quark decays as a venue to search for light dark force carriers. The top quark is the heaviest particle in the standard model whose decays are relatively poorly measured, allowing sufficient room for exotic decay modes from new physics. A very light (GeV scale) dark gauge boson (Z') is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the 3.6sigma deviation in the muon g-2 measurement. We present and study a possible scenario that top quark decays as t-->bW+Z's. This is the same as the dominant top quark decay (t-->bW) accompanied by one or multiple dark force carriers. The Z' can be easily boosted, and it can decay into highly collimated leptons (lepton-jet) with large branching ratio. We discuss the implications for the Large Hadron Collider experiments including the analysis based on the lepton-jets.
Neutrinoless double beta decay experiments
K. Zuber
2006-10-04T23:59:59.000Z
The study of neutrinoless double beta decay is of outmost importance for neutrino physics. It is considered to be the gold plated channel to probe the fundamental character of neutrinos and to determine the neutrino mass. From the experimental point about nine different isotopes are explored for the search. After a general introduction follows a short discussion on nuclear matrix element calculations and supportive measurements. The current experimental status of double beta searches is presented followed by a short discussion of the ideas and proposals for large scale experiments.
Hyman, BC; Iacob, VE; Azhari, A.; Gagliardi, Carl A.; Hardy, John C.; Mayes, VE; Neilson, RG; Sanchez-Vega, M.; Tang, X.; Trache, L.; Tribble, Robert E.
2003-01-01T23:59:59.000Z
A high-speed tape-transport system was used to measure the half-life of 62Ga. The radioactive beam exited the vacuum system through a thin Kapton window and then passed through a 300-mm-thick plastic scintillator that pro- vided a continuous... the 62Ga decay data to remove anomolous cycles. For each cycle, we extracted the ratio of events de- tected in the 4p counter relative to the number of 62Ga nu- clei detected in the plastic scintillator at the exit of MARS. We rejected cycles...
Electroweak penguin decays at LHCb
Thomas Blake
2011-09-29T23:59:59.000Z
Promising ways to search for New Physics effects in radiative penguin decays are in the angular analysis of $B_{d} \\rightarrow K^{*0} \\mu^{+}\\mu^{-}$, in the measurement of direct CP violation in $\\B_{d} \\rightarrow K^{*0}\\mu^{+}\\mu^{-}$ and a time dependent analysis of $B_{s} \\rightarrow \\phi \\gamma$. All of these studies are being pursued at LHCb. First results will be shown from the 2010 and early 2011 data, with particular emphasis on $B_{d} \\rightarrow K^{*0} \\mu^{+}\\mu^{-}$.
Neutrinoless Double Beta Decay and CP Violation
Patrick J. O'Donnell; Utpal Sarkar
1993-05-27T23:59:59.000Z
We study the relation between the Majorana neutrino mass matrices and the neutrinoless double beta decay when CP is not conserved. We give an explicit form of the decay rate in terms of a rephasing invariant quantity and demonstrate that in the presence of CP violation it is impossible to have vanishing neutrinoless double beta decay in the case of two neutrino generations (or when the third generation leptons do not mix with other leptons and hence decouple).
Experimental study of rare charged pion decays
Dinko Pocanic; Emil Frlez; Andries van der Schaaf
2014-07-10T23:59:59.000Z
The combination of simple dynamics, small number of available decay channels, and extremely well controlled radiative and loop corrections, make charged pion decays a sensitive means for testing the underlying symmetries and the universality of weak fermion couplings, as well as for improving our understanding of pion structure and chiral dynamics. This paper reviews the current state of experimental study of the allowed rare decays of charged pions: (a) leptonic, $\\pi^+ \\to e^+\
The Decay of the Neutron or Beta Decay, the Big Bang, and the...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Decay of the Neutron or Beta Decay, the Big Bang, and the Left-Handed Universe Apr 03 2014 01:00 PM - 02:30 PM Geoffrey L. Greene Physics Division, ORNL Research Accelerator...
Neutrinoless Double Beta Decay and Neutrino Masses
Michael Duerr
2012-06-04T23:59:59.000Z
Neutrinoless double beta decay is a promising test for lepton number violating physics beyond the standard model of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between neutrinoless double beta decay and Majorana neutrino masses provided by the so-called Schechter--Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate neutrinoless double beta decay from unknown nuclear background using only one isotope, i.e., within one experiment.
Neutrinoless Double Beta Decay: Present and Future
Oliviero Cremonesi
2002-10-04T23:59:59.000Z
Present status, and future plans for Double Beta Decay searches are reviewed. Given the recent observations of neutrino oscillations, a possibility to observe $\\beta\\beta(0\
New limits for neutrinoless tau decays
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Zhou, L.
1998-05-01T23:59:59.000Z
double beta decays, neutrino oscillations, Z!l11l22 decays, and other rare pro- cesses. In particular, there are strict limits on muon neutrino- less decays: B(m!eg),4.9310211 and B(m!eee),2.4 310212 at 90% confidence level @18#. However, lepton num- ber... particles and on the new coupling constants. The most optimistic branching fraction predictions are at the level of about 1026. Constraints on lepton flavor violation come from studies of rare and forbidden K , p, and m decays, e-m conversions, neutrinoless...
Spectroscopy of element 115 decay chains
Rudolph, Dirk [Lund University, Sweden; Forsberg, U. [Lund University, Sweden; Golubev, P. [Lund University, Sweden; Sarmiento, L. G. [Lund University, Sweden; Yakushev, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Andersson, L.-L. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Di Nitto, A. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Duehllmann, Ch. E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Gates, J. M. [Lawrence Berkeley National Laboratory (LBNL); Gregorich, K. E. [Lawrence Berkeley National Laboratory (LBNL); Gross, Carl J [ORNL; Hessberger, F. P. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Herzberg, R.-D [University of Liverpool; Khuyagbaatar, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Kratz, J. V. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Rykaczewski, Krzysztof Piotr [ORNL; Schaedel, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Aberg, S. [Lund University, Sweden; Ackermann, D. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Block, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Brand, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Carlsson, B. G. [Lund University, Sweden; Cox, D. [University of Liverpool; Derkx, X. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Eberhardt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Even, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Fahlander, C. [Lund University, Sweden; Gerl, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Jaeger, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kindler, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Krier, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kojouharov, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kurz, N. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Lommel, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mistry, A. [University of Liverpool; Mokry, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Nitsche, H. [Lawrence Berkeley National Laboratory (LBNL); Omtvedt, J. P. [Paul Scherrer Institut, Villigen, Switzerland; Papadakis, P. [University of Liverpool; Ragnarsson, I. [Lund University, Sweden; Runke, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schaffner, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schausten, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Thoerle-Pospiech, P. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Torres, T. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Traut, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Tuerler, A. [Paul Scherrer Institut, Villigen, Switzerland; Ward, A. [University of Liverpool; Ward, D. E. [Lund University, Sweden; Wiehl, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany
2013-01-01T23:59:59.000Z
A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.
Nuclear beta-decay measurements and |Vud|
Dan Melconian
2011-08-11T23:59:59.000Z
Some recent work in nuclear beta decay related to the value of |Vud| is described along with some near-term goals for future measurements.
Displacement Echoes: Classical Decay and Quantum Freeze
Petitjean, Cyril [Departement de Physique Theorique, Universite de Geneve, CH-1211 Geneva 4 (Switzerland); Bevilaqua, Diego V. [Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States); Heller, Eric J. [Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States); Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States); Jacquod, Philippe [Physics Department, University of Arizona, Tucson, Arizona 85721 (United States)
2007-04-20T23:59:59.000Z
Motivated by neutron scattering experiments, we investigate the decay of the fidelity with which a wave packet is reconstructed by a perfect time-reversal operation performed after a phase-space displacement. In the semiclassical limit, we show that the decay rate is generically given by the Lyapunov exponent of the classical dynamics. For small displacements, we additionally show that, following a short-time Lyapunov decay, the decay freezes well above the ergodic value because of quantum effects. Our analytical results are corroborated by numerical simulations.
Displacement Echoes: Classical Decay and Quantum Freeze
Cyril Petitjean; Diego V. Bevilaqua; Eric J. Heller; Philippe Jacquod
2007-04-23T23:59:59.000Z
Motivated by neutron scattering experiments, we investigate the decay of the fidelity with which a wave packet is reconstructed by a perfect time-reversal operation performed after a phase space displacement. In the semiclassical limit, we show that the decay rate is generically given by the Lyapunov exponent of the classical dynamics. For small displacements, we additionally show that, following a short-time Lyapunov decay, the decay freezes well above the ergodic value because of quantum effects. Our analytical results are corroborated by numerical simulations.
Operator Analysis of Neutrinoless Double Beta Decay
Kiwoon Choi; Kwang Sik Jeong; Wan Young Song
2002-07-19T23:59:59.000Z
We study the effective operators of the standard model fields which would yield an observable rate of neutrinoless double beta decay. We particularly focus on the possibility that neutrinoless double beta decay is dominantly induced by lepton-number-violating higher dimensional operators other than the Majorana neutrino mass. Our analysis can be applied to models in which neutrinoless double beta decay is induced either by a strong dynamics or by quantum gravity effects at a fundamental scale near the TeV scale as well as the conventional models in which neutrinoless double beta decay is induced by perturbative renormalizable interactions.
Review of double beta decay experiments
A. S. Barabash
2014-03-12T23:59:59.000Z
The brief review of current experiments on search and studying of double beta decay processes is done. Best present limits on $\\langle m_{\
The Neutral Decay Modes of the Eta-Meson
B. M. K. Nefkens; J. W. Price
2002-02-11T23:59:59.000Z
The neutral decay modes of the eta meson are reviewed. The most recent results obtained with the Crystal Ball multiphoton detector at BNL are incorporated. This includes a new, precise result for the slope parameter alpha of the Dalitz plot in eta -> 3pi0 decay and a new, lower branching ratio for eta -> pi0 gamma gamma which is consistent with chiral perturbation theory. Recently-obtained limits are given for novel tests of CP and C invariance based on several rare eta decays.
Overconstrained estimates of neutrinoless double beta decay within the QRPA
Amand Faessler; Gianluigi Fogli; Eligio Lisi; Vadim Rodin; Anna Maria Rotunno; Fedor Simkovic
2008-05-29T23:59:59.000Z
Estimates of nuclear matrix elements for neutrinoless double beta decay (0nu2beta) based on the quasiparticle random phase approximations (QRPA) are affected by theoretical uncertainties, which can be substantially reduced by fixing the unknown strength parameter g_pp of the residual particle-particle interaction through one experimental constraint - most notably through the two-neutrino double beta decay (2nu2beta) lifetime. However, it has been noted that the g_pp adjustment via 2\
Neutrinoless double beta decay and neutrino physics
Werner Rodejohann
2012-08-20T23:59:59.000Z
The connection of neutrino physics with neutrinoless double beta decay is reviewed. After presenting the current status of the PMNS matrix and the theoretical background of neutrino mass and lepton mixing, we will summarize the various implications of neutrino physics for double beta decay. The influence of light sterile neutrinos and other exotic modifications of the three neutrino picture is also discussed.
Testing the Standard Model with Kaon Decays
Matthew Moulson
2012-09-15T23:59:59.000Z
During the last few years, new experimental and theoretical results have allowed ever more stringent tests of the Standard Model to be performed using kaon decays. This overview of recent progress includes an updated evaluation of the CKM matrix element Vus. Tests of CKM unitarity and gauge universality and lepton universality tests with Kl2 and Kl3 decays are discussed.
Higgs boson decay to Ali Abbasabadi
Repko, Wayne
Higgs boson decay to #22;#22;#22; Ali Abbasabadi Department of Physical Sciences, Ferris State, East Lansing, Michigan 48824, USA (April 17, 2000) The Higgs boson decay, H ! #22;#22;#22; , is studied in the Standard Model at the tree and one-loop levels. It is shown that for Higgs boson masses above 110 Ge
Neutrinoless Double Beta Decay in Light of SNO Salt Data
Murayama, Hitoshi
2009-01-01T23:59:59.000Z
Limits From Neutrinoless Double-Beta Decay (Rev. ),” incan also cause neutrinoless double-beta decay (see e.g. , [LBNL-53996 Neutrinoless Double Beta Decay in Light of SNO
A Search for Neutrinoless Double Beta Decay of Te-130
Bryant, Adam Douglas
2010-01-01T23:59:59.000Z
A Search for Neutrinoless Double Beta Decay of Te by AdamA Search for Neutrinoless Double Beta Decay of CopyrightA Search for Neutrinoless Double Beta Decay of Te by Adam
Lepton flavor violation in Higgs boson decays under the rare...
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Complementarity of Neutrinoless Double Beta Decay and Cosmology
Dodelson, Scott; Lykken, Joseph
2014-03-20T23:59:59.000Z
Neutrinoless double beta decay experiments constrain one combination of neutrino parameters, while cosmic surveys constrain another. This complementarity opens up an exciting range of possibilities. If neutrinos are Majorana particles, and the neutrino masses follow an inverted hierarchy, then the upcoming sets of both experiments will detect signals. The combined constraints will pin down not only the neutrino masses but also constrain one of the Majorana phases. If the hierarchy is normal, then a beta decay detection with the upcoming generation of experiments is unlikely, but cosmic surveys could constrain the sum of the masses to be relatively heavy, thereby producing a lower bound for the neutrinoless double beta decay rate, and therefore an argument for a next generation beta decay experiment. In this case as well, a combination of the phases will be constrained.
Double beta decay experiments: beginning of a new era
A. S. Barabash
2012-09-19T23:59:59.000Z
The review of current experiments on search and studying of double beta decay processes is done. Results of the most sensitive experiments are discussed and values of modern limits on effective Majorana neutrino mass ($) are given. New results on two neutrino double beta decay are presented. The special attention is given to new current experiments with mass of studied isotopes more than 100 kg, EXO--200 and KamLAND--Zen. These experiments open a new era in research of double beta decay. In the second part of the review prospects of search for neutrinoless double beta decay in new experiments with sensitivity to $$ at the level of $\\sim 0.01-0.1$ eV are discussed. Parameters and characteristics of the most perspective projects (CUORE, GERDA, MAJORANA, SuperNEMO, EXO, KamLAND--Zen, SNO+) are given.
Search for: "neutrinoless double beta decay" | DOE PAGES
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Gauss-Bonnet Term on Vacuum Decay
Rong-Gen Cai; Bin Hu; Seoktae Koh
2008-11-20T23:59:59.000Z
We study the effect of the Gauss-Bonnet term on vacuum decay process in the Coleman-De Luccia formalism. The Gauss-Bonnet term has an exponential coupling with the real scalar field, which appears in the low energy effective action of string theories. We calculate numerically the instanton solution, which describes the process of vacuum decay, and obtain the critical size of bubble. We find that the Gauss-Bonnet term has a nontrivial effect on the false vacuum decay, depending on the Gauss-Bonnet coefficient.
Closed strings from decaying D-branes
Neil Lambert; Hong Liu; Juan Maldacena
2007-02-05T23:59:59.000Z
We compute the emission of closed string radiation from homogeneous rolling tachyons. For an unstable decaying D$p$-brane the radiated energy is infinite to leading order for $p\\leq 2$ and finite for $p>2$. The closed string state produced by a decaying brane is closely related to the state produced by D-instantons at a critical Euclidean distance from $t=0$. In the case of a D0 brane one can cutoff this divergence so that we get a finite energy final state which would be the state that the brane decays into.
Higgs boson decay to mu mubar gamma
Ali Abbasabadi; Wayne W. Repko
2000-04-17T23:59:59.000Z
The Higgs boson decay, H -> mu mubar gamma, is studied in the Standard Model at the tree and one-loop levels. It is shown that for Higgs boson masses above 110 GeV, the contribution to the radiative width from the one-loop level exceeds the contribution from the tree level, and for Higgs boson masses above 140 GeV, it even exceeds the contribution from the tree level decay H -> mu mubar. We also show that the contributions to the radiative decay width from the interference terms between the tree and one-loop diagrams are negligible.
Reheating dynamics affects non-perturbative decay of spectator fields
Enqvist, Kari; Lerner, Rose N.; Rusak, Stanislav, E-mail: kari.enqvist@helsinki.fi, E-mail: rose.lerner@helsinki.fi, E-mail: stanislav.rusak@helsinki.fi [University of Helsinki and Helsinki Institute of Physics, P.O. Box 64, FI-00014, Helsinki (Finland)
2013-11-01T23:59:59.000Z
The behaviour of oscillating scalar spectator fields after inflation depends on the thermal background produced by inflaton decay. Resonant decay of the spectator is often blocked by large induced thermal masses. We account for the finite decay width of the inflaton and the protracted build-up of the thermal bath to determine the early evolution of a homogeneous spectator field ? coupled to the Higgs Boson ? through the term g{sup 2}?{sup 2}?{sup 2}, the only renormalisable coupling of a new scalar to the Standard Model. We find that for very large higgs-spectator coupling g?>10{sup ?3}, the resonance is not always blocked as was previously suggested. As a consequence, the oscillating spectator can decay quickly. For other parameter values, we find that although qualitative features of the thermal blocking still hold, the dynamics are altered compared to the instant decay case. These findings are important for curvaton models, where the oscillating field must be relatively long lived in order to produce the curvature perturbation. They are also relevant for other spectator fields, which must decay sufficiently early to avoid spoiling the predictions of baryogenesis and nucleosynthesis.
Dark matter from decaying topological defects
Hindmarsh, Mark [Helsinki Institute of Physics, Gustaf Hällströmin katu, P.O. Box 64, 00014 Helsinki University (Finland); Kirk, Russell; West, Stephen M., E-mail: m.b.hindmarsh@sussex.ac.uk, E-mail: russell.kirk.2008@live.rhul.ac.uk, E-mail: stephen.west@rhul.ac.uk [Dept. of Physics, Royal Holloway University of London, Egham Hill, Egham, Surrey, TW20 0EX (United Kingdom)
2014-03-01T23:59:59.000Z
We study dark matter production by decaying topological defects, in particular cosmic strings. In topological defect or ''top-down'' (TD) scenarios, the dark matter injection rate varies as a power law with time with exponent p?4. We find a formula in closed form for the yield for all p < 3/2, which accurately reproduces the solution of the Boltzmann equation. We investigate two scenarios (p = 1, p = 7/6) motivated by cosmic strings which decay into TeV-scale states with a high branching fraction into dark matter particles. For dark matter models annihilating either by s-wave or p-wave, we find the regions of parameter space where the TD model can account for the dark matter relic density as measured by Planck. We find that topological defects can be the principal source of dark matter, even when the standard freeze-out calculation under-predicts the relic density and hence can lead to potentially large ''boost factor'' enhancements in the dark matter annihilation rate. We examine dark matter model-independent limits on this scenario arising from unitarity and discuss example model-dependent limits coming from indirect dark matter search experiments. In the four cases studied, the upper bound on G? for strings with an appreciable channel into TeV-scale states is significantly more stringent than the current Cosmic Microwave Background limits.
Phenomenology of neutrinoless double beta decay
J. J. Gómez-Cadenas; Justo Martín-Albo
2015-02-25T23:59:59.000Z
This paper reviews the current status and future outlook of neutrinoless double beta decay searches, which try to provide an answer to the fundamental question of whether neutrinos are Dirac or Majorana particles.
Recent Results in Neutrinoless Double Beta Decay
Lisa J. Kaufman
2013-05-14T23:59:59.000Z
The search for neutrinoless double beta decay is a rich source for new physics. The observation of this decay will lead to understanding of the absolute mass scale of neutrinos, the Majorana nature of the neutrino (whether the neutrino is its own anti-particle), and lepton number violation. Double beta decay is being investigated around the world by several experiments using different candidate isotopes. There has been much progress made in experimental techniques recently such that achieving sensitivity to neutrino masses at 50 meV and below will be possible in the near future. A summary of recent results in neutrinoless double beta decay is discussed with a look toward the experimental goals for the future.
Phenomenology of neutrinoless double beta decay
Gómez-Cadenas, J J
2015-01-01T23:59:59.000Z
This paper reviews the current status and future outlook of neutrinoless double beta decay searches, which try to provide an answer to the fundamental question of whether neutrinos are Dirac or Majorana particles.
Double beta decay and neutrino mass models
Helo, J C; Ota, T; Santos, F A Pereira dos
2015-01-01T23:59:59.000Z
Neutrinoless double beta decay allows to constrain lepton number violating extensions of the standard model. If neutrinos are Majorana particles, the mass mechanism will always contribute to the decay rate, however, it is not a priori guaranteed to be the dominant contribution in all models. Here, we discuss whether the mass mechanism dominates or not from the theory point of view. We classify all possible (scalar-mediated) short-range contributions to the decay rate according to the loop level, at which the corresponding models will generate Majorana neutrino masses, and discuss the expected relative size of the different contributions to the decay rate in each class. We also work out the phenomenology of one concrete 2-loop model in which both, mass mechanism and short-range diagram, might lead to competitive contributions, in some detail.
Theory of top quark production and decay
Kuehn, J.H. [Universitaet Karlsruhe (Germany)
1997-01-01T23:59:59.000Z
Direct and indirect information on the top quark mass and its decay modes is reviewed. The theory of top production in hadron- and electron-positron-colliders is presented.
DIRECT PHOTONS FROM Y(3100) DECAY
Ronan, M.T.
2010-01-01T23:59:59.000Z
to search for direct photons from 0(3100) decay. V* havedecay, but a sianal of high energy direct photons remains.this excess of direct photons wi*h OCD predictions and
CP Violation in Neutrinoless Double Beta Decay
T. Fukuyama; K. Matsuda; H. Nishiura
1997-08-19T23:59:59.000Z
We argue three-flavour neutrino mixing. We consider the neutrinos as Majorana particles and see how the neutrinoless double beta decay constrains the neutrino mixing angles. Our formulation is widely valid and is applied to the neutrino oscillation experiment.
Effective field theories for inclusive B decays
Lee, Keith S. M. (Keith Seng Mun)
2006-01-01T23:59:59.000Z
In this thesis, we study inclusive decays of the B meson. These allow one to determine CKM elements precisely and to search for physics beyond the Standard Model. We use the framework of effective field theories, in ...
Neutrino Decay and Solar Neutrino Seasonal Effect
Picoreti, R; de Holanda, P C; Peres, O L G
2015-01-01T23:59:59.000Z
We consider the possibility of solar neutrino decay as a sub-leading effect on their propagation between production and detection. Using current oscillation data, we set a new lower bound to the $\
Decay of helical Kelvin waves on a quantum vortex filament
Van Gorder, Robert A., E-mail: rav@knights.ucf.edu [Department of Mathematics, University of Central Florida, Orlando, Florida 32816-1364 (United States)
2014-07-15T23:59:59.000Z
We study the dynamics of helical Kelvin waves moving along a quantum vortex filament driven by a normal fluid flow. We employ the vector form of the quantum local induction approximation (LIA) due to Schwarz. For an isolated filament, this is an adequate approximation to the full Hall-Vinen-Bekarevich-Khalatnikov dynamics. The motion of such Kelvin waves is both translational (along the quantum vortex filament) and rotational (in the plane orthogonal to the reference axis). We first present an exact closed form solution for the motion of these Kelvin waves in the case of a constant amplitude helix. Such solutions exist for a critical wave number and correspond exactly to the Donnelly-Glaberson instability, so perturbations of such solutions either decay to line filaments or blow-up. This leads us to consider helical Kelvin waves which decay to line filaments. Unlike in the case of constant amplitude helical solutions, the dynamics are much more complicated for the decaying helical waves, owing to the fact that the rate of decay of the helical perturbations along the vortex filament is not constant in time. We give an analytical and numerical description of the motion of decaying helical Kelvin waves, from which we are able to ascertain the influence of the physical parameters on the decay, translational motion along the filament, and rotational motion, of these waves (all of which depend nonlinearly on time). One interesting finding is that the helical Kelvin waves do not decay uniformly. Rather, such waves decay slowly for small time scales, and more rapidly for large time scales. The rotational and translational velocity of the Kelvin waves depend strongly on this rate of decay, and we find that the speed of propagation of a helical Kelvin wave along a quantum filament is large for small time while the wave asymptotically slows as it decays. The rotational velocity of such Kelvin waves along the filament will increase over time, asymptotically reaching a finite value. These decaying Kelvin waves correspond to wave number below the critical value for the Donnelly-Glaberson instability, and hence our results on the Schwarz quantum LIA correspond exactly to what one would expect from prior work on the Donnelly-Glaberson instability.
Searches for neutrinoless double beta decay
B. Schwingenheuer
2012-01-24T23:59:59.000Z
Neutrinoless double beta decay is a lepton number violating process whose observation would also establish that neutrinos are their own anti-particles. There are many experimental efforts with a variety of techniques. Some (EXO, Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has reported the first measurement of the half life for the double beta decay with two neutrinos of $^{136}$Xe. The sensitivities of the different proposals are reviewed.
Rare meson decays into very light neutralinos
O'Leary, Ben [Institut fuer Theoretische Physik, RWTH Aachen University, 52056 Aachen (Germany)
2010-02-10T23:59:59.000Z
Results are presented for the two-body decays of mesons into light neutralinos and from the first complete calculation of the loop-induced decays of kaons to pions plus light neutralinos and of B mesons to kaons plus light neutralinos. The branching ratios are shown to be strongly suppressed within the MSSM with minimal flavor violation, and no bounds on the neutralino mass can be inferred from experimental data, i.e. a massless neutralino is allowed.
First forbidden beta decay in light nuclei
Millener, D.J.; Warburton, E.K.
1984-01-01T23:59:59.000Z
Beta decay matrix elements for the operators sigma dot del and sigma dot r are calculated for eight J/sup +/ ..-->.. J/sup -/ or J/sup -/ ..-->.. J/sup +/ beta transitions. Results using harmonic oscillator wave functions differ markedly from those using more realistic Woods-Saxon wave functions. A substantial contribution to the sigma dot del matrix elements from pion exchange currents is required to reproduce the experimental beta decay rates. 15 references.
Fidelity Decay for Phase Space Displacements
Diego V. Bevilaqua; Eric J. Heller
2004-09-03T23:59:59.000Z
In this letter we analyse the behavior of fidelity decay under a very specific kind of perturbation: phase space displacements. Under these perturbations, systems will decay following the Lyapunov regime only. Others universal regimes discussed in the literature are not presented in this case; instead, for small values of the perturbation we observe quantum freeze of the fidelity. We also show that it is possible to connect this result with the incoherent neutron scattering problem
Neutrinoless double beta decay with scalar bilinears
H. V. Klapdor-Kleingrothaus; U. Sarkar
2002-11-18T23:59:59.000Z
One possible probe to physics beyond the standard model is to look for scalar bilinears, which couple to two fermions of the standard model. We point out that the scalar bilinears allow new diagrams contributing to the neutrinoless double beta decay. The upper bound on the neutrinoless double beta decay lifetime would then give new constraints on the ratio of the masses of these scalars to their couplings to the fermions.
False Starts in History of Searches for 2{beta} Decay, or Discoverless Double Beta Decay
Tretyak, V. I. [Institute for Nuclear Research, MSP 03680, Kyiv (Ukraine)
2011-12-16T23:59:59.000Z
A collection of stories is presented on discoveries of 2{beta} decay (including neutrinoless one) which were refuted in the subsequent investigations.
Calculated final state probability distributions for T2 -decay measurements
Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 1.6.1 Neutrinoless double beta decay . . . . . . . . . . . . . . . . . . . . 19 1.6.2 Cosmological
Power Spectrum Analyses of Nuclear Decay Rates
D. Javorsek II; P. A. Sturrock; R. N. Lasenby; A. N. Lasenby; J. B. Buncher; E. Fischbach; J. T. Gruenwald; A. W. Hoft; T. J. Horan; J. H. Jenkins; J. L. Kerford; R. H. Lee; A. Longman; J. J. Mattes; B. L. Morreale; D. B. Morris; R. N. Mudry; J. R. Newport; D. O'Keefe; M. A. Petrelli; M. A. Silver; C. A. Stewart; B. Terry
2010-07-06T23:59:59.000Z
We provide the results from a spectral analysis of nuclear decay data displaying annually varying periodic fluctuations. The analyzed data were obtained from three distinct data sets: 32Si and 36Cl decays reported by an experiment performed at the Brookhaven National Laboratory (BNL), 56Mn decay reported by the Children's Nutrition Research Center (CNRC), but also performed at BNL, and 226Ra decay reported by an experiment performed at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. All three data sets exhibit the same primary frequency mode consisting of an annual period. Additional spectral comparisons of the data to local ambient temperature, atmospheric pressure, relative humidity, Earth-Sun distance, and their reciprocals were performed. No common phases were found between the factors investigated and those exhibited by the nuclear decay data. This suggests that either a combination of factors was responsible, or that, if it was a single factor, its effects on the decay rate experiments are not a direct synchronous modulation. We conclude that the annual periodicity in these data sets is a real effect, but that further study involving additional carefully controlled experiments will be needed to establish its origin.
Neutrino Decay and Neutrinoless Double Beta Decay in a 3-3-1 Model
Alex G. Dias; A. Doff; C. A. de S. Pires; P. S. Rodrigues da Silva
2005-08-11T23:59:59.000Z
In this work we show that the implementation of spontaneous breaking of the lepton number in the 3-3-1 model with right-handed neutrinos gives rise to fast neutrino decay with majoron emission and generates a bunch of new contributions to the neutrinoless double beta decay.
Neutrino decay and neutrinoless double beta decay in a 3-3-1 model
Dias, Alex G. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66.318, 05315-970, Sao Paulo-SP (Brazil); Doff, A. [Instituto de Fisica Teorica, Universidade Estadual Paulista, Rua Pamplona 145, 01405-900 Sao Paulo-SP (Brazil); Pires, C.A. de S; Rodrigues da Silva, P.S. [Departamento de Fisica, Universidade Federal da Paraiba, Caixa Postal 5008, 58051-970, Joao Pessoa-PB (Brazil)
2005-08-01T23:59:59.000Z
In this work we show that the implementation of spontaneous breaking of the lepton number in the 3-3-1 model with right-handed neutrinos gives rise to fast neutrino decay with Majoron emission and generates a bunch of new contributions to the neutrinoless double beta decay.
Nonmesonic Weak Decay Dynamics from proton spectra of $?$-Hypernuclei
Franjo Krmpotic; Cláudio De Conti
2015-03-06T23:59:59.000Z
A novel comparison between the data and the theory is proposed for the nonmesonic (NM) weak decay of hypernuclei. Instead of confronting the primary decay rates, as is usually done, we focus attention on the effective decay rates that are straightforwardly related with the number of emitted particles. Proton kinetic energy spectra of $^5_\\Lambda$He, $^7_\\Lambda$Li, $^9_\\Lambda$Be, $^{11}_\\Lambda$B, $^{12}_{\\Lambda}$C, $^{13}_\\Lambda$C, $^{15}_{\\Lambda}$N and $^{16}_{\\Lambda}$O, measured by FINUDA, are evaluated theoretically. The Independent Particle Shell Model (IPSM) is used as the nuclear structure framework, while the dynamics is described by the One-Meson-Exchange (OME) potential. Only for the $^{5}_{\\Lambda}$He, $^{7}_{\\Lambda}$Li, and $^{12}_{\\Lambda}$C hypernuclei is it possible to make a comparison with the data, since for the rest there is no published experimental information on number of produced hypernuclei. Considering solely the one-nucleon-induced ($1N$-NM) decay channel, the theory reproduces correctly the shapes of all three spectra at medium and high energies ($E_p \\geq 40 $ MeV). Yet, it greatly overestimates their magnitudes, as well as the corresponding transition rates when the full OME ($\\pi+K+ \\eta+\\rho+\\omega+K^*$) model is used. The agreement is much improved when only the $\\pi+K$ mesons with soft dipole cutoff parameters participate in the decay process. We find that the IPSM is a fair first order approximation to disentangle the dynamics of the $1N$-NM decay, the knowledge of which is indispensable to inquire about the baryon-baryon strangeness-flipping interaction. It is shown that the IPSM provides very useful insights regarding the determination the $2N$-NM decay rate. In a new analysis of the FINUDA data, we derive two results for this quantity with one of them close to that obtained previously.
The search for neutrinoless double beta decay
J. J. Gomez-Cadenas; J. Martin-Albo; M. Mezzetto; F. Monrabal; M. Sorel
2012-01-16T23:59:59.000Z
In the last two decades the search for neutrinoless double beta decay has evolved into one of the highest priorities for understanding neutrinos and the origin of mass. The main reason for this paradigm shift has been the discovery of neutrino oscillations, which clearly established the existence of massive neutrinos. An additional motivation for conducting such searches comes from the existence of an unconfirmed, but not refuted, claim of evidence for neutrinoless double decay in $^{76}\\text{Ge}$. As a consequence, a new generation of experiments, employing different detection techniques and $\\beta\\beta$ isotopes, is being actively promoted by experimental groups across the world. In addition, nuclear theorists are making remarkable progress in the calculation of the neutrinoless double beta decay nuclear matrix elements, thus eliminating a substantial part of the theoretical uncertainties affecting the particle physics interpretation of this process. In this report, we review the main aspects of the double beta decay process and some of the most relevant experiments. The picture that emerges is one where searching for neutrinoless double beta decay is recognized to have both far-reaching theoretical implications and promising prospects for experimental observation in the near future.
New experiment on the neutron radiative decay
Khafizov R. U.; Kolesnikov I. A.; Tolokonnikov S. V.; Torokhov V. D.; Solovei V. A.; Kolhidashvili M. R.; Konorov I. A
2009-10-05T23:59:59.000Z
The report is dedicated to the preparation of the new experiment on the neutron radiative decay what is conducted for the last years. We started the experimental research of this neutron decay branch with the experiment conducted at ILL in 2002 and continued in another experiment at the second and third cycles at the FRMII reactor of the Technical University of Munich in 2005. In the first experiment we succeeded in measuring only the upper limit on the relative intensity (B.R.) of the radiative neutron decay and in the second we succeeded in discovering events of radiative neutron decay and measure its B.R.=(3.2+-1.6)10-3 (with C.L.=99.7% and gamma quanta energy over 35 keV). The obtained average B.R. value was approximately twice the theoretical value calculated earlier within the framework of the standard electroweak model. However, due to significant experimental error it would be preliminary to deduce that based on this finding a deviation from the standard model has been observed. To prove or disprove the existence of a deviation it is necessary to conduct a new experiment that would allow to measure the radiative peak in timing spectra with precision in the order of 1%. By the present time we have prepared a new experiment the main result of which would be the measurement of B.R. for the radiative branch of neutron decay with this precision.
Amplitude analyses of the decays ?c1?????? and ?c1??'????
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Adams, G. S.; Napolitano, J.; Ecklund, K. M.; Insler, J.; Muramatsu, H.; Park, C. S.; Pearson, L. J.; Thorndike, E. H.; Ricciardi, S.; Thomas, C.; et al
2011-12-01T23:59:59.000Z
Using a data sample of 2.59×10? ?(2S) decays obtained with the CLEO-c detector, we perform amplitude analyses of the complementary decay chains ?(2S)???c1; ?c1?????? and ?(2S)???c1; ?c1??'????. We find evidence for an exotic P-wave ?'? amplitude, which, if interpreted as a resonance, would have parameters consistent with the ??(1600) state reported in other production mechanisms. We also make the first observation of the decay a?(980)??'? and measure the ratio of branching fractions B(a?(980)??'?)/B(a?(980)???)=0.064±0.014±0.014. The ?? spectrum produced with a recoiling ? is compared to that with ?' recoil.
Phenomenology of neutrinoless double beta decay
M. Hirsch
2006-09-15T23:59:59.000Z
Neutrinoless double beta decay violates lepton number by two units, a positive observation therefore necessarily implies physics beyond the standard model. Here, three possible contributions to neutrinoless double beta decay are briefly reviewed: (a) The mass mechanism and its connection to neutrino oscillations; (b) Left-right symmetric models and the lower limit on the right-handed W boson mass; and (c) R-parity violating supersymmetry. In addition, the recently published ``extended black box'' theorem is briefly discussed. Combined with data from oscillation experiments this theorem provides proof that the neutrinoless double beta decay amplitude must receive a non-zero contribution from the mass mechanism, if neutrinos are indeed Majorana particles.
Correlations and the neutrinoless double beta decay
Menendez, J.; Poves, A. [Departamento de Fisica Teorica, and IFT, UAM-CSIC, Universidad Autonoma de Madrid, 28049-Madrid (Spain); Caurier, E.; Nowacki, F. [IPHC, IN2P3-CNRS/Universite Louis Pasteur, 67037-Strasbourg (France)
2009-11-09T23:59:59.000Z
We explore the influence of the deformation on the nuclear matrix elements of the neutrinoless double beta decay (NME), concluding that the difference in deformation -or more generally on the amount of quadrupole correlations- between parent and grand daughter nuclei quenchs strongly the decay. We discuss how varies the nuclear matrix element of {sup 76}Ge decay when the wave functions of the two nuclei involved in the transition are constrained to reproduce the experimental occupancies. In the Interacting Shell Model description the value of the NME is enhanced about 15% compared to previous calculations, whereas in the QRPA the NME's are reduced by 20%-30%, thus, the discrepancies between both approaches diminish.
Inflaton dark matter from incomplete decay
Mar Bastero-Gil; Rafael Cerezo; Joao G. Rosa
2015-01-22T23:59:59.000Z
We show that the decay of the inflaton field may be incomplete, while nevertheless successfully reheating the universe and leaving a stable remnant that accounts for the present dark matter abundance. We note, in particular, that since the mass of the inflaton decay products is field-dependent, one can construct models, endowed with an appropriate discrete symmetry, where inflaton decay is kinematically forbidden at late times and only occurs during the initial stages of field oscillations after inflation. We show that this is sufficient to ensure the transition to a radiation-dominated era and that inflaton particles typically thermalize in the process. They eventually decouple and freeze out, yielding a thermal dark matter relic. We discuss possible implementations of this generic mechanism within consistent cosmological and particle physics scenarios, for both single-field and hybrid inflation.
Lepton Flavor Violating Decays - Review & Outlook
Toshinori Mori
2006-05-31T23:59:59.000Z
Here I review the status and prospects of experimental investigations into lepton flavor violation (LFV) in charged leptons. Rare LFV processes are naturally expected to occur through loops of TeV scale particles predicted by supersymmetric theories or other models beyond the Standard Model. In contrast to physics of quark flavors that is dominated by the Cabibbo-Kobayashi-Maskawa matrix, LFV in charged leptons is a definitive signal of new physics. Currently active researches are rare tau decay searches at the B factories. The MEG experiment will soon start a sensitive search for the LFV muon decay, mu to e gamma. Prospects for searches at the LHC, a possibility of a fixed target LFV experiment with high energy muons, and a sensitivity of leptonic kaon decays to LFV are also briefly discussed.
Inclusive radiative {psi}(2S) decays
Libby, J.; Martin, L.; Powell, A.; Thomas, C.; Wilkinson, G. [University of Oxford, Oxford OX1 3RH (United Kingdom); Mendez, H. [University of Puerto Rico, Mayaguez, Puerto Rico 00681 (Puerto Rico); Ge, J. Y.; Miller, D. H.; Shipsey, I. P. J.; Xin, B. [Purdue University, West Lafayette, Indiana 47907 (United States); Adams, G. S.; Hu, D.; Moziak, B.; Napolitano, J. [Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Ecklund, K. M. [Rice University, Houston, Texas 77005 (United States); He, Q.; Insler, J.; Muramatsu, H.; Park, C. S.; Thorndike, E. H. [University of Rochester, Rochester, New York 14627 (United States)] (and others)
2009-10-01T23:59:59.000Z
Using e{sup +}e{sup -} collision data taken with the CLEO-c detector at the Cornell Electron Storage Ring, we have investigated the direct photon spectrum in the decay {psi}(2S){yields}{gamma}gg. We determine the ratio of the inclusive direct photon decay rate to that of the dominant three-gluon decay rate {psi}(2S){yields}ggg (R{sub {gamma}}{identical_to}{gamma}({gamma}gg)/{gamma}(ggg)) to be R{sub {gamma}}(z{sub {gamma}}>0.4)=0.070{+-}0.002{+-}0.019{+-}0.011, with z{sub {gamma}} defined as the scaled photon energy relative to the beam energy. The errors shown are statistical, systematic, and that due to the uncertainty in the input branching fractions used to extract the ratio, respectively.
Rare K decays: Challenges and Perspectives
Christopher Smith
2014-09-22T23:59:59.000Z
At this stage of the LHC program, the prospect for a new physics signal in the very rare K ---> pi nu nu bar decays may be dented, but remains well alive thanks to their intrinsic qualities. First, these decays are among the cleanest observables in the quark flavor sector. When combined with their terrible suppression in the Standard Model, they thus offer uniquely sensitive probes. Second, the LHC capabilities are not ideal for all kinds of new physics, even below the TeV scale. For example, rather elusive scenarios like natural-SUSY-like hierarchical spectrum, baryon number violation, or new very light but very weakly interacting particles may well induce deviations in rare K decays. Even though experimentalists should brace themselves for tiny deviations, these modes thus have a clear role to play in the LHC era.
Neutrinoless double beta decay and nuclear matrix elements
Simkovic, Fedor [BLTP, JINR Dubna, 141980 Dubna, Moscow region (Russian Federation); Comenius University, Mlynska dolina, Bratislava (Slovakia)
2011-11-23T23:59:59.000Z
The fundamental importance of searching for neutrinoless double-beta decay (0{nu}{beta}{beta}-decay) is widely recognized. Observation of the decay would tell us that the total lepton number is not conserved and that, consequently, neutrinos are massive Majorana fermions. The 0{nu}{beta}{beta}-decay is discussed in context of neutrino oscillation data. The perspectives of the experimental 0{nu}{beta}{beta}-decay searches are analyzed. The importance of reliable determination of the 0{nu}{beta}{beta}-decay nuclear matrix elements is pointed out.
Symmetry violations in nuclear and neutron $\\beta$ decay
Vos, K K; Timmermans, R G E
2015-01-01T23:59:59.000Z
The role of $\\beta$ decay as a low-energy probe of physics beyond the Standard Model is reviewed. Traditional searches for deviations from the Standard Model structure of the weak interaction in $\\beta$ decay are discussed in the light of constraints from the LHC and the neutrino mass. Limits on the violation of time-reversal symmetry in $\\beta$ decay are compared to the strong constraints from electric dipole moments. Novel searches for Lorentz symmetry breaking in the weak interaction in $\\beta$ decay are also included, where we discuss the unique sensitivity of $\\beta$ decay to test Lorentz invariance. We end with a roadmap for future $\\beta$-decay experiments.
Review of New Rare Hadronic B-decay Results
James G. Smith
2006-06-01T23:59:59.000Z
We present a new result from Belle and many new results from BABAR for rare hadronic B decays. These include measurements of decays involving baryons, a Dalitz plot analysis of the three-charged-kaon system, many new results for B decays to eta'X and omegaX, and a limit for the decay B-> a_1 rho. Measurements of the vector-vector decays B->rhoKstar and B->omegaKstar are helping to understand the value of the longitudinal polarization fraction for these B->VV decays.
The double-beta decay: Theoretical challenges
Horoi, Mihai [Department of Physics, Central Michigan University, Mount Pleasant, Michigan, 48859 (United States)
2012-11-20T23:59:59.000Z
Neutrinoless double beta decay is a unique process that could reveal physics beyond the Standard Model of particle physics namely, if observed, it would prove that neutrinos are Majorana particles. In addition, it could provide information regarding the neutrino masses and their hierarchy, provided that reliable nuclear matrix elements can be obtained. The two neutrino double beta decay is an associate process that is allowed by the Standard Model, and it was observed for about ten nuclei. The present contribution gives a brief review of the theoretical challenges associated with these two process, emphasizing the reliable calculation of the associated nuclear matrix elements.
Neutrinoless double beta decay and neutrino masses
Duerr, Michael [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)
2012-07-27T23:59:59.000Z
Neutrinoless double beta decay (0{nu}{beta}{beta}) is a promising test for lepton number violating physics beyond the standard model (SM) of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between 0{nu}{beta}{beta} and Majorana neutrino masses provided by the so-called Schechter-Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate 0{nu}{beta}{beta} from unknown nuclear background using only one isotope, i.e., within one experiment.
Attractor Explosions and Catalyzed Vacuum Decay
Green, Daniel; Silverstein, Eva; Starr, David
2006-05-05T23:59:59.000Z
We present a mechanism for catalyzed vacuum bubble production obtained by combining moduli stabilization with a generalized attractor phenomenon in which moduli are sourced by compact objects. This leads straightforwardly to a class of examples in which the Hawking decay process for black holes unveils a bubble of a different vacuum from the ambient one, generalizing the new endpoint for Hawking evaporation discovered recently by Horowitz. Catalyzed vacuum bubble production can occur for both charged and uncharged bodies, including Schwarzschild black holes for which massive particles produced in the Hawking process can trigger vacuum decay. We briefly discuss applications of this process to the population and stability of metastable vacua.
Electromagnetic corrections to pseudoscalar decay constants
Benjamin Glaessle; Gunnar S. Bali
2011-11-16T23:59:59.000Z
The effects of electromagnetic interactions on pseudoscalar decay constants are investigated. Using a compact QED and QCD action we are able to resolve differences of about 0.1 MeV. We obtain the preliminary results f_pi^0-f_pi^+/- =0.09(3) MeV and f_D^0-f_D^+/- =0.79(11) MeV for light and charmed pseudoscalar decay constants on a N_f=2 nonperturbatively improved Sheikholeslami-Wohlert ensemble.
Quantum gravitational proton decay at high temperature
Ulf H. Danielsson
2005-12-29T23:59:59.000Z
One of the most important challenges of contemporary physics is to find experimental signatures of quantum gravity. It is expected that quantum gravitational effects lead to proton decay but on time scales way beyond what is of any relevance to experiments. At non-zero temperatures there are reasons to believe that the situation is much more favourable. We will argue that at the temperatures and densities reached at present and future fusion facilities there is a realistic possibility that proton decay could be detectable.
Study of the K0L ???????¯decay
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ogata, R.; Suzuki, S.; Ahn, J. K.; Akune, Y.; Baranov, V.; Chen, K. F.; Comfort, J.; Doroshenko, M.; Fujioka, Y.; Hsiung, Y. B.; Inagaki, T.; Ishibashi, S.; Ishihara, N.; Ishii, H.; Iwai, E.; Iwata, T.; Kato, I.; Kobayashi, S.; Komatsu, S.; Komatsubara, T. K.; Kurilin, A. S.; Kuzmin, E.; Lednev, A.; Lee, H. S.; Lee, S. Y.; Lim, G. Y.; Ma, J.; Matsumura, T.; Moisseenko, A.; Morii, H.; Morimoto, T.; Nakajima, Y.; Nakano, T.; Nanjo, H.; Nishi, N.; Nix, J.; Nomura, T.; Nomachi, M.; Okuno, H.; Omata, K.; Perdue, G. N.; Perov, S.; Podolsky, S.; Porokhovoy, S.; Sakashita, K.; Sasaki, T.; Sasao, N.; Sato, H.; Sato, T.; Sekimoto, M.; Shimogawa, T.; Shinkawa, T.; Stepanenko, Y.; Sugaya, Y.; Sugiyama, A.; Sumida, T.; Tajima, Y.; Takita, S.; Tsamalaidze, Z.; Tsukamoto, T.; Tung, Y. C.; Wah, Y. W.; Watanabe, H.; Wu, M. L.; Yamaga, M.; Yamanaka, T.; Yoshida, H. Y.; Yoshimura, Y.; Zheng, Y.
2011-09-01T23:59:59.000Z
The rare decay K0L???????? was studied with the E391a detector at the KEK 12-GeV proton synchrotron. Based on 9.4×10? K0L decays, an upper limit of 8.1×10?? was obtained for the branching fraction at 90% confidence level. We also set a limit on the K0L?????X (X?invisible particles) process; the limit on the branching fraction varied from 7.0×10?? to 4.0×10?? for the mass of X ranging from 50 MeV/c² to 200 MeV/c².
Lattice String Breaking and Heavy Meson Decays
I T Drummond; R R Horgan
1998-11-11T23:59:59.000Z
We show how string breaking on the lattice, treated as a mixing effect, can be related to decay rates for heavy quark systems. We use this to make a preliminary calculation of the energy split at maximum mixing for static quarks in QCD from the decay rate for $\\Upsilon(4S)\\to B{\\bar B}$. We extend the calculation to achieve rough estimates for the contributions of channels involving $B, B^*, B_s and B_s^*$ mesons to the width of the $\\Upsilon(5S)$.
Lynch, Morgan H
2015-01-01T23:59:59.000Z
In this paper we apply the formalism of Accelerated Quantum Dynamics (AQD) to the radiative stopping of highly relativistic electrons in ice. We compute the lifetime of electrons to decay into muons as well as the spectrum of the emitted muons. The energy of the emitted muon depends on the deceleration of the electron and this correlation can be used to tag the event and confirm the prediction. The results predict the acceleration-induced decay of electrons at IceCube energies. This experimental setting has the potential to establish the existence of the Unruh effect as well investigate the role of high acceleration in particle physics.
Gravitational decay of the Z boson
Nieves, Jose F.; Pal, Palash B. [Laboratory of Theoretical Physics, Department of Physics, P.O. Box 23343, University of Puerto Rico, Rio Piedras, 00931-3343 (Puerto Rico); Saha Institute of Nuclear Physics, 1/AF Bidhan-Nagar, Calcutta 700064 (India)
2005-11-01T23:59:59.000Z
We study the decay process of the Z boson to a photon and a graviton. The most general form of the on-shell amplitude, subject to the constraints due to the conservation of the electromagnetic current and the energy-momentum tensor, is determined. The amplitude is expressed in terms of three form factors, two of which are CP odd while one is CP even. The latter, which is the only nonzero form factor at the one-loop level, is computed in the standard model and the decay rate is determined.
Observation of ?cJ decays to ??¯¯¯????
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ablikim, M.; Achasov, M. N.; Ambrose, D. J.; An, F. F.; An, Q.; An, Z. H.; Bai, J. Z.; Ban, Y.; Becker, J.; Bennett, J. V.; et al
2012-09-01T23:59:59.000Z
Decays of the ?cJ states (J=0, 1, 2) to ??¯¯¯????, including processes with intermediate ?(1385), are studied through the E1 transition ?'???cJ using 106×10? ?' events collected with the BESIII detector at BEPCII. This is the first observation of ?cJ decays to the final state ??¯¯¯????. The branching ratio of the intermediate process ?cJ??(1385)±?¯¯¯(1385)? is also measured for the first time, and the results agree with the theoretical predictions based on the color-octet effect.
Majorana neutrino masses and the neutrinoless double-beta decay
Faessler, A. [University of Tuebingen, Institute of Theoretical Physics (Germany)], E-mail: amand.faessler@uni-tuebingen.de
2006-12-15T23:59:59.000Z
Neutrinoless double-beta decay is forbidden in the Standard Model of electroweak and strong interaction but allowed in most Grand Unified Theories (GUTs). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass is neutrinoless double-beta decay allowed. Apart from one claim that the neutrinoless double-beta decay in {sup 76}Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow one to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUTs and the minimal R-parity-violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUTs. For that, one has to assume that the specific mechanism is the leading one for neutrinoless double-beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present work, one discusses the accuracy of the present status of calculating of the nuclear matrix elements and the corresponding limits of GUTs and supersymmetric parameters.
Neutrino masses and Neutrinoless Double Beta Decay: Status and expectations
Oliviero Cremonesi
2010-02-07T23:59:59.000Z
Two most outstanding questions are puzzling the world of neutrino Physics: the possible Majorana nature of neutrinos and their absolute mass scale. Direct neutrino mass measurements and neutrinoless double beta decay (0nuDBD) are the present strategy to solve the puzzle. Neutrinoless double beta decay violates lepton number by two units and can occurr only if neutrinos are massive Majorana particles. A positive observation would therefore necessarily imply a new regime of physics beyond the standard model, providing fundamental information on the nature of the neutrinos and on their absolute mass scale. After the observation of neutrino oscillations and given the present knowledge of neutrino masses and mixing parameters, a possibility to observe 0nuDBDD at a neutrino mass scale in the range 10-50 meV could actually exist. This is a real challenge faced by a number of new proposed projects. Present status and future perpectives of neutrinoless double-beta decay experimental searches is reviewed. The most important parameters contributing to the experimental sensitivity are outlined. A short discussion on nuclear matrix element calculations is also given. Complementary measurements to assess the absolute neutrino mass scale (cosmology and single beta decays) are also discussed.
The COBRA Double Beta Decay Experiment
Dawson, J. V. [Department of Physics and Astronomy, University of Sussex, Brighton. BN1 9QH (United Kingdom)
2007-03-28T23:59:59.000Z
The progress of the COBRA neutrinoless double beta decay experiment is discussed. Potential backgrounds are described. Estimates on the contamination levels of 214Bi in the detectors have been made using previously acquired low background data. New crystals with a different passivation material show an improved background count rate of approximately one order of magnitude.
Gluon Radiation in Top Production and Decay
Cosmin Macesanu; Lynne H. Orr
2000-01-14T23:59:59.000Z
We present the results of an exact calculation of gluon radiation in top production and decay at high energy electron-positron colliders. We include all spin correlations and interferences, the bottom quark mass, and finite top width effects in the matrix element calculation. We study properties of the radiated gluons and implications for top mass measurement.
Adaptive cache decay Paolo Bennati, Roberto Giorgi
Giorgi, Roberto
to save power. Our idea is to adaptively select mostly used cache lines. We found that this can MiBench suite for ARM based processor, show 13% improvement in leakage saving and 21% in EDP versus drowsy cache and 52% improvement in leakage saving and 65% in EDP versus cache decay (in average
Cowan, Ray Franklin
We report the result of a search for the rare decay B0??? [B superscript 0???] in 426??fb-1 [fb superscript -1] of data, corresponding to 226×106 B0B? 0 [226 x 10 superscript 6 B superscript 0 B? superscript 0] pairs, ...
?-Decay in Ultra-Intense Laser Fields
Serban Misicu; Margarit Rizea
2013-07-05T23:59:59.000Z
We investigate the \\alpha-decay of a spherical nucleus under the influence of an ultra-intense laser field for the case when the radius vector joining the center-of-masses of the \\alpha-particle and the daughter is aligned with the direction of the external field. The time-independent part of the \\alpha-daughter interaction is taken from elastic scattering compilations whereas the time-varying part describes the interaction between the decaying system with the laser field. The time-dependent Schr\\"odinger equation is solved numerically by appealing to a modified scheme of the Crank-Nicolson type where an additional first-order time derivative appears compared to the field-free case. The tunneling probability of the \\alpha-cluster, and derived quantities (decay rate, total flux) is determined for various laser intensities and frequencies for either continous waves or few-cycle pulses of envelope function F(t)=1. We show that in the latter case pulse sequences containing an odd number of half-cycles determine an enhancement of the tunneling probability compared to the field-free case and the continuous wave case. The present study is carried out taking as example the alpha decaying nucleus $^{106}$Te.
Rare semi-leptonic B meson decays
Lyon, James David
2014-06-28T23:59:59.000Z
In this thesis, novel corrections to B ? X? and B ? Xl+l- decays, where X is a pseudoscalar or vector meson, are presented. These are the chromomagnetic matrix element, weak annihilation in a general four-quark operator basis and a long...
Nuclear physics aspects of double beta decay
Petr Vogel
2008-07-15T23:59:59.000Z
Comprehensive description of the phenomenology of the $\\beta\\beta$ decay is given, with emphasis on the nuclear physics aspects. After a brief review of the neutrino oscillation results and of motivation to test the lepton number conservation, the mechanism of the $0\
Vacuum decay into Anti de Sitter space
Juan Maldacena
2011-01-10T23:59:59.000Z
We propose an interpretation of decays of a false vacuum into an $AdS$ region. The $AdS$ region is interpreted in terms of a dual field theory living on an end of the world brane which expands into the false vacuum.
Remarkable Features of Decaying Hagedorn States
M. Beitel; K. Gallmeister; C. Greiner
2014-07-02T23:59:59.000Z
Hagedorn states (HS) are a tool to model the hadronization process which occurs in the phase transition phase between the quark gluon plasma (QGP) and the hadron resonance gas (HRG). Their abundance is believed to appear near the Hagedorn temperature $T_H$ which in our understanding equals the critical temperature $T_c$. These hadron-like resonances are characterized by being very massive and by not being limited to quantum numbers of known hadrons. To generate a whole zoo of such new states we solve the covariantly formulated bootstrap equation by regarding energy conservation and conservation of the baryon number $B$, strangeness $S$ and electric charge $Q$. To investigate their decay properties decay chain calculations of HS were conducted. One single (heavy) HS with certain quantum numbers decays by various two-body decay channels subsequently into final stable hadrons. Multiplicities of these stable hadrons, their ratios and their energy distributions are presented. Strikingly the final energy spectra of resulting hadrons show a thermal-like distribution with the characteristic Hagedorn temperature $T_H$. All hadronic properties like masses, spectral functions etc. are taken from the hadronic transport model Ultra Relativistic Quantum Molecular Dynamics (UrQMD).
Search for neutrinoless ? decays: ??e? and ????
Baringer, Philip S.
1997-04-01T23:59:59.000Z
A search for the lepton-family-number-violating decays ??e? and ???? has been performed using CLEO II data. No evidence of a signal has been found and the corresponding upper limits are B(??e?)<2.7×10(-6) and B(????)<3.0×10(-6) at 90% C.L....
Search for rare and forbidden eta ' decays
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Davis, Robin E. P.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Zhou, X.
2000-01-01T23:59:59.000Z
We have searched for rare and forbidden decays of the eta' meson in hadronic events at the CLEO II detector. The search is conducted on 4.80 fb(-1) of e(+)e(-) collisions at 10.6 GeV center-of-mass energy at the Cornell Electron Storage Ring. We...
Finding slowly decaying observables Gary Froyland \\Lambda
Froyland, Gary
Finding slowly decaying observables Gary Froyland \\Lambda Department of Mathematical Engineering initial transient behaviour to disappear. We present a rigorous numerical method for (i) estimating distribution on M ; that is, if you plot the orbit on a computer, you see the same distribution of dots. We
Neutrinoless Double Beta Decay in Light of SNO Salt Data
Murayama, Hitoshi
2009-01-01T23:59:59.000Z
Beta Decay in Light of SNO Salt Data Hitoshi Murayama andBeta Decay in Light of SNO Salt Data Hitoshi Murayama ? andIn the SNO data from its salt run, probably the most signi?
Method of predicting mechanical properties of decayed wood
Kelley, Stephen S.
2003-07-15T23:59:59.000Z
A method for determining the mechanical properties of decayed wood that has been exposed to wood decay microorganisms, comprising: a) illuminating a surface of decayed wood that has been exposed to wood decay microorganisms with wavelengths from visible and near infrared (VIS-NIR) spectra; b) analyzing the surface of the decayed wood using a spectrometric method, the method generating a first spectral data of wavelengths in VIS-NIR spectra region; and c) using a multivariate analysis to predict mechanical properties of decayed wood by comparing the first spectral data with a calibration model, the calibration model comprising a second spectrometric method of spectral data of wavelengths in VIS-NIR spectra obtained from a reference decay wood, the second spectral data being correlated with a known mechanical property analytical result obtained from the reference decayed wood.
{alpha} decay and recoil decay tagging studies of {sup 183}Tl
Raddon, P.M.; Jenkins, D.G.; O'Leary, C.D.; Simons, A.J.; Wadsworth, R. [Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Andreyev, A.N.; Page, R.D. [Oliver Lodge Laboratory, Department of Physics, University of Liverpool, Liverpool, L69 7ZE (United Kingdom); Carpenter, M.P. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Kondev, F.G. [Technology Development Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Enqvist, T.; Greenlees, P.T.; Jones, P.M.; Julin, R.; Juutinen, S.; Kettunen, H.; Leino, M.; Leppaenen, A.-P.; Nieminen, P.; Pakarinen, J.; Rahkila, P. [Department of Physics, University of Jyvaeskylae, FIN-40351, Jyvaeskylae (Finland)] [and others
2004-12-01T23:59:59.000Z
High-spin states in the nucleus {sup 183}Tl have been studied using the recoil decay tagging and recoil tagging techniques. The data have enabled new structures to be identified which are believed to be based on prolate f{sub 7/2}, h{sub 9/2}, and oblate h{sub 9/2} configurations. In addition, the prolate i{sub 3/2} structure has also been extended. The systematics of the newly identified structures will be discussed. The {alpha} decay of {sup 183}Tl has also been investigated. Examination of both delayed and prompt {gamma} rays in coincidence with the prominent 6333-keV {alpha} decay, together with an investigation of the effects of the summing of L electrons, allow assignment of transitions and the construction of tentative low-spin decay schemes for {sup 179}Au and {sup 175}Ir.
Neutrinoless Double Beta Decay and Physics Beyond the Standard Model
Frank F. Deppisch; Martin Hirsch; Heinrich Päs
2012-08-03T23:59:59.000Z
Neutrinoless double beta decay is the most powerful tool to probe not only for Majorana neutrino masses but for lepton number violating physics in general. We discuss relations between lepton number violation, double beta decay and neutrino mass, review a general Lorentz invariant parametrization of the double beta decay rate, highlight a number of different new physics models showing how different mechanisms can trigger double beta decay, and finally discuss possibilities to discriminate and test these models and mechanisms in complementary experiments.
Search for neutrinoless double beta decay with NEMO 3 experiment
Zornitza Daraktchieva
2009-01-18T23:59:59.000Z
NEMO 3 experiment is designed to search for neutrinoless double beta decay. It is located in the Modane Underground Laboratory (LSM) and has been taking data since February 2003. The half- lives of two neutrino beta decay have been measured for seven isotopes. No evidence of neutrinoless double beta decay has been found. The limits on both the half-lives of the neutrinoless double beta decay and the corresponding Majorana effective masses are derived
The Neutrinoless Double Beta Decay: The Case for Germanium Detectors
A. Morales; J. Morales
2002-11-21T23:59:59.000Z
An overview of the current status of Neutrinoless Double Beta Decay is presented, emphasizing on the case of Germanium Detectors.
Search for neutrinoless decays of the tau lepton
Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Lam, H.
1994-10-01T23:59:59.000Z
. The upper limits obtained for 22 decay branching fractions are several times more stringent than those set previously....
Baryonic matter perturbations in decaying vacuum cosmology
Marttens, R.F. vom; Zimdahl, W. [Departamento de Física, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Campus de Goiabeiras, CEP 29075-910, Vitória, Espírito Santo (Brazil); Hipólito-Ricaldi, W.S., E-mail: rodrigovonmarttens@gmail.com, E-mail: wiliam.ricaldi@ufes.br, E-mail: winfried.zimdahl@pq.cnpq.br [Departamento de Ciências Naturais, Universidade Federal do Espírito Santo, CEUNES, Rodovia BR 101 Norte, km. 60, CEP 29932-540, São Mateus, Espírito Santo (Brazil)
2014-08-01T23:59:59.000Z
We consider the perturbation dynamics for the cosmic baryon fluid and determine the corresponding power spectrum for a ?(t)CDM model in which a cosmological term decays into dark matter linearly with the Hubble rate. The model is tested by a joint analysis of data from supernovae of type Ia (SNIa) (Constitution and Union 2.1), baryonic acoustic oscillations (BAO), the position of the first peak of the anisotropy spectrum of the cosmic microwave background (CMB) and large-scale-structure (LSS) data (SDSS DR7). While the homogeneous and isotropic background dynamics is only marginally influenced by the baryons, there are modifications on the perturbative level if a separately conserved baryon fluid is included. Considering the present baryon fraction as a free parameter, we reproduce the observed abundance of the order of 5% independently of the dark-matter abundance which is of the order of 32% for this model. Generally, the concordance between background and perturbation dynamics is improved if baryons are explicitly taken into account.
Two surface plasmon decay of plasma oscillations
Kluge, Thomas; Zeil, Karl; Bussmann, Michael; Schramm, Ulrich; Cowan, Thomas E
2015-01-01T23:59:59.000Z
The interaction of ultra-intense lasers with solid foils can be used to accelerate ions to high energies well exceeding 60 MeV. The non-linear relativistic motion of electrons in the intense laser radiation leads to their acceleration and later to the acceleration of ions. Ions can be accelerated from the front surface, the foil interior region, and the foil rear surface (TNSA, most widely used), or the foil may be accelerated as a whole if sufficiently thin (RPA). Here, we focus on the most widely used mechanism for laser ion-acceleration of TNSA. Starting from perfectly flat foils we show by simulations how electron filamentation at or inside the solid leads to a spatial modulations in the ions. The exact dynamics depend very sensitively on the chosen initial parameters which has a tremendous effect on electron dynamics. In the case of step-like density gradients we find evidence that suggests a two-surface-plasmon decay of plasma oscillations triggering a Raileigh-Taylor-like instability.
Sensitivity of CUORE to Neutrinoless Double-Beta Decay
Alessandria, F.
2013-01-01T23:59:59.000Z
of CUORE to Neutrinoless Double-Beta Decay b c,:L d e f F .s t results on neutrinoless double beta decay of T e w i t hthe study of neutrinoless double beta decay, J . C r y s t .
The Majorana Neutrinoless Double-Beta Decay Experiment
Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group
The Majorana Neutrinoless Double-Beta Decay Experiment Pre-conceptual Design Proposal November 22 Motivation for Neutrinoless Double-Beta Decay Experiments . . . . . . . . . 4 2.1.1 Community Guidance Neutrinoless Double-Beta Decay Results . . . . . . . . . . . . . . . . . . . . 12 2.5 Next
Symmetry relations in charmless B->PPP decays
Michael Gronau; Jonathan L. Rosner
2005-11-04T23:59:59.000Z
Strangeness-changing decays of $B$ mesons to three-body final states of pions and kaons are studied, assuming that they are dominated by a $\\Delta I=0$ penguin amplitude with flavor structure $\\bar b \\to \\bar s$. Numerous isospin relations for $B\\to K\\pi\\pi$ and for underlying quasi-two-body decays are compared successfully with experiment, in some cases resolving ambiguities in fitting resonance parameters. The only exception is a somewhat small branching ratio noted in $B^0\\to K^{*0}\\pi^0$, interpreted in terms of destructive interference between a penguin amplitude and an enhanced electroweak penguin contribution. Relations for B decays into three kaons are derived in terms of final states involving $K_S$ or $K_L$, assuming that $\\phi K$-subtracted decay amplitudes are symmetric in $K$ and $\\bar K$, as has been observed experimentally. Rates due to nonresonant backgrounds are studied using a simple model, which may reduce discrete ambiguities in Dalitz plot analyses.
Symmetry relations in charmless B{yields}PPP decays
Gronau, Michael; Rosner, Jonathan L. [Department of Physics, Technion-Israel Institute of Technology, Technion City, 32000 Haifa (Israel); Enrico Fermi Institute and Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 (United States)
2005-11-01T23:59:59.000Z
Strangeness-changing decays of B mesons to three-body final states of pions and kaons are studied, assuming that they are dominated by a {delta}I=0 penguin amplitude with flavor structure b{yields}s. Numerous isospin relations for B{yields}K{pi}{pi} and for underlying quasi-two-body decays are compared successfully with experiment, in some cases resolving ambiguities in fitting resonance parameters. The only exception is a somewhat small branching ratio noted in B{sup 0}{yields}K*{sup 0}{pi}{sup 0}, interpreted in terms of destructive interference between a penguin amplitude and an enhanced electroweak penguin contribution. Relations for B decays into three kaons are derived in terms of final states involving K{sub S} or K{sub L}, assuming that {phi}K-subtracted decay amplitudes are symmetric in K and K, as has been observed experimentally. Rates due to nonresonant backgrounds are studied using a simple model, which may reduce discrete ambiguities in Dalitz plot analyses.
The dynamics of universe for exponential decaying dark energy
Bostan, Nilay
2015-01-01T23:59:59.000Z
In this study we consider an exponential decaying form for dark energy as EoS parameter in order to discuss the dynamics of the universe. Firstly, assuming that universe is filled with an ideal fluid which consists of exponential decaying dark energy we obtain time dependent behavior of several physical quantities such as energy density, pressure and others for dark energy, dark energy-matter coupling and non-coupling cases. Secondly, using scalar field instead of an ideal fluid we obtain these physical quantities in terms of scalar potential and kinetic term for the same cases in scalar-tensor formalism. Finally we show that ideal fluid and scalar-tensor description of dark energy give mathematically equivalent results for this EoS parameter.
The dynamics of universe for exponential decaying dark energy
Nilay Bostan; Ekrem Aydiner
2015-08-12T23:59:59.000Z
In this study we consider an exponential decaying form for dark energy as EoS parameter in order to discuss the dynamics of the universe. Firstly, assuming that universe is filled with an ideal fluid which consists of exponential decaying dark energy we obtain time dependent behavior of several physical quantities such as energy density, pressure and others for dark energy, dark energy-matter coupling and non-coupling cases. Secondly, using scalar field instead of an ideal fluid we obtain these physical quantities in terms of scalar potential and kinetic term for the same cases in scalar-tensor formalism. Finally we show that ideal fluid and scalar-tensor description of dark energy give mathematically equivalent results for this EoS parameter.
TauDecay: a library to simulate polarized tau decays via FeynRules and MadGraph5
Kaoru Hagiwara; Tong Li; Kentarou Mawatari; Junya Nakamura
2014-12-15T23:59:59.000Z
TauDecay is a library of helicity amplitudes to simulate polarized tau decays, constructed in the FeynRules and MadGraph5 framework. Together with the leptonic mode, the decay library includes the main hadronic modes, \\tau \\to \
B Decays in a General Left-Right Symmetric Model
Frank, Mariana; Turan, Ismail
2010-01-01T23:59:59.000Z
Motivated by recently observed disagreements with the SM predictions in B decays, we study $b \\to d, s$ transitions in a general class of $SU(2)_L \\times SU(2)_R \\times U(1)_{B-L}$ models, with a simple one-parameter structure of the right handed mixing matrix for the quarks, which obeys the constraints from kaon physics. We use experimental constraints on the branching ratios of $b \\to s \\gamma$, $b \\to c e {\\bar \
The nuclear matrix elements for neutrinoless double beta decay
Simkovic, Fedor [Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina, SK-84248 Bratislava (Slovakia)
2007-10-12T23:59:59.000Z
The status of calculation of the neutrinoless double beta decay (0{nu}{beta}{beta}-decay) nuclear matrix elements (NME's) is reviewed. The spread of published values of NME's is discussed. The main attention is paid to the recent progress achieved in the evaluation of the 0{nu}{beta}{beta}-decay NME's in the framework of the quasiparticle random phase approximation (QRPA). The obtained results are compared with those of the nuclear shell model. The problem of reliable determination of the 0{nu}{beta}{beta}-decay NME's is addressed. The uncertainty in NME's are analyzed and further progress in calculation of the 0{nu}{beta}{beta}-decay NME's is outlined.
Search for ? and ? ? invisible decays in J / ? ? ? ? and ? ? ?
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ablikim, M.; Achasov, M. N.; Albayrak, O.; Ambrose, D. J.; An, F. F.; An, Q.; Bai, J. Z.; Ban, Y.; Becker, J.; Bennett, J. V.; Bertani, M.; Bian, J. M.; Boger, E.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; Ding, W. M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Fang, J.; Fang, S. S.; Fava, L.; Feng, C. Q.; Ferroli, R. B.; Friedel, P.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, T.; Guo, Y. P.; Han, Y. L.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, G. M.; Huang, G. S.; Huang, J. S.; Huang, L.; Huang, X. T.; Huang, Y.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Kopf, B.; Kornicer, M.; Kuehn, W.; Lai, W.; Lange, J. S.; Leyhe, M.; Li, C. H.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, K.; Li, Lei; Li, Q. J.; Li, S. L.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Liao, X. T.; Lin, D.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H.; Liu, H. B.; Liu, H. H.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K.; Liu, K. Y.; Liu, Kai; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. Y.; Maas, F. E.; Maggiora, M.; Malik, Q. A.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Morales Morales, C.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nicholson, C.; Nikolaev, I. B.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Park, J. W.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Prencipe, E.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, X. S.; Qin, Y.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schaefer, B. D.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Toth, D.; Ullrich, M.; Varner, G. S.; Wang, B. Q.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q. J.; Wang, S. G.; Wang, X. F.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, Q. G.; Wen, S. P.; Werner, M.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, S. X.; Wu, W.; Wu, Z.; Xia, L. G.; Xia, Y. X.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, G. M.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Xu, Z. R.; Xue, F.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, H. W.; Yu, J. S.; Yu, S. P.; Yuan, C. Z.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, LiLi; Zhang, R.; Zhang, S. H.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhang, Zhenghao; Zhao, G.; Zhao, H. S.; Zhao, J. W.; Zhao, K. X.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. Z.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zhong, B.; Zhong, Z.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. M.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.
2013-01-01T23:59:59.000Z
Using a sample of (225.3±2.8)×10? J/? decays collected with the BESIII detector at BEPCII, searches for invisible decays of ? and ?' in J/???? and ??' are performed. Decays of ??K?K? are used to tag the ? and ?' decays. No signals above background are found for the invisible decays, and upper limits at the 90% confidence level are determined to be 2.6×10?? for the ratio B(??invisible)/B(????) and 2.4×10?² for B(?'?invisible)/B(?'???). These limits may be used to constrain light dark matter particles or spin-1 U bosons.
D meson hadronic decays at CLEO-c
Yang, Fan; /Fermilab
2011-01-01T23:59:59.000Z
The recent CLEO-c results on hadronic decays of D and D{sub s} mesons are presented. First the absolute branching fractions for D and D{sub s} mesons using a double tag technique are discussed, then are the Cabibbo suppressed decays and doubly Cabibbo suppressed decays. Finally, I present the inclusive and rare decay modes and other measurements from CLEO-c. These decays illuminate a wide range of physics. A brief theoretical introduction is given before the corresponding discussion on measurement.
Probing neutrinoless double beta decay with SNO+
Evelina Arushanova; Ashley R. Back
2015-05-01T23:59:59.000Z
Probing neutrinoless double beta decay is one of the primary goals for SNO+, SNOLAB's multi-purpose neutrino detector. In order to achieve this goal the SNO detector has been adapted so that it can be filled with Te-loaded liquid scintillator. During the initial double beta phase the target loading is 0.3% natural Te, which equates to $\\sim790$ kg of double beta isotope. Estimating the sensitivity to neutrinoless double beta decay requires a well understood background model. For SNO+ this is provided by a comprehensive study considering all possible background contributions, whether they originate from within the liquid scintillator cocktail, the surrounding parts of the detector or other irreducible backgrounds. Given these considerations, for five years running in the initial phase, the expected sensitivity is $T_{1/2}^{0\
Probing neutrinoless double beta decay with SNO+
Arushanova, Evelina
2015-01-01T23:59:59.000Z
Probing neutrinoless double beta decay is one of the primary goals for SNO+, SNOLAB's multi-purpose neutrino detector. In order to achieve this goal the SNO detector has been adapted so that it can be filled with Te-loaded liquid scintillator. During the initial double beta phase the target loading is 0.3% natural Te, which equates to $\\sim790$ kg of double beta isotope. Estimating the sensitivity to neutrinoless double beta decay requires a well understood background model. For SNO+ this is provided by a comprehensive study considering all possible background contributions, whether they originate from within the liquid scintillator cocktail, the surrounding parts of the detector or other irreducible backgrounds. Given these considerations, for five years running in the initial phase, the expected sensitivity is $T_{1/2}^{0\
Importance of neutrinoless double beta decay
Utpal Sarkar
2007-12-17T23:59:59.000Z
A natural explanation for the smallness of the neutrino mass requires them to be Majorana particles violating lepton number by two units. Since lepton number violation can have several interesting consequences in particle physics and cosmology, it is of utmost importance to find out if there is lepton number violation in nature and what is its magnitude. The neutrinoless double beta decay experiment can answer these questions: if there is lepton number violation and if neutrinos are Majorana particles. In addition, the magnitude of neutrinoless double beta decay will constrain any other lepton number violating processes. This lepton number violation may also be relatd to the matter-antimatter asymmetry of the universe, dark matter and cosmological constant.
Searches for very rare decays of kaons
Lang, K. [Univ. of Texas, Austin, TX (United States)
1997-01-01T23:59:59.000Z
The physics motivation for searches for very rare kaon decays, either forbidden or suppressed within the Standard Model, is briefly discussed. Simple arguments conclude that such searches probe possible new forces at a 200 TeV mass scale or constitute a precision test of the electroweak model. The examples of such process are decays of K{sub L}{sup 0} {yields} {mu} {sup {+-}}e{sup -+}, K{sup +} {yields} {pi}{sup +} {mu}{sup +} e{sup -}, K{sub L}{sup 0} {yields} {mu}{sup +} {mu}{sup -}, and K{sup +} {yields} {pi} {yields} {pi}{sup +}{nu}{bar {nu}}. We present the current experimental status and describe the new efforts to reach sensitivities down to one part in 10{sup 12}. The discussion is focused on the experimental program at the Alternating Gradient Synchrotron at Brookhaven National Laboratory, where intense beams make such studies possible.
Axions from cosmic string and wall decay
Hagmann, C A
2010-03-10T23:59:59.000Z
If inflation occurred with a reheat temperature > T{sub PQ}, axions from the decay of global axion strings and domain walls would make an important contribution to the cosmological energy density, comparable to that from vacuum misalignment. Several groups have numerically studied the evolution of axion strings and walls in the past, however substantial uncertainties remain in their contribution to the present density {Omega}{sub a,string+wall} {approx} 1-100 (f{sub a}/10{sup 12} GeV){sup 7/6}, where f{sub a} is the axion decay constant. I will describe the numerical methods used in our simulations and show results for several string and wall configurations.
Axions from cosmic string and wall decay
Hagmann, Chris [Lawrence Livermore National Laboratory, L-59, 7000 East Ave, Livermore, CA (United States)
2010-08-30T23:59:59.000Z
If inflation occurred with a reheat temperature > T{sub PQ}, axions from the decay of global axion strings and domain walls would make an important contribution to the cosmological energy density, comparable to that from vacuum misalignment. Several groups have numerically studied the evolution of axion strings and walls in the past, however substantial uncertainties remain in their contribution to the present density {Omega}{sub a,string+wall{approx}}1-100(f{sub a}/10{sup 12} GeV){sup 7/6}, where f{sub a} is the axion decay constant. I will describe the numerical methods used in our simulations and show results for several string and wall configurations.
Neutrinoless Double Beta Decay and its "Inverse"
Clemens A. Heusch; Peter Minkowski
1996-11-18T23:59:59.000Z
Recent considerations by these authors pointed out the attractive features which a search for the exchange of heavy Majorana neutrinos could have for solving the mass and the lepton number puzzles for all neutrinos, in TeV-level electron-electron scattering. In the present note, we show that, contrary to subsequently published arguments, non-observation of neutrinoless double beta decay has, to date, no bearing on the promise of this important task for future linear electron colliders.
Discovery of the $^{151}$Eu $\\alpha$ decay
Casali, N; Orio, F; Pattavina, L; Beeman, J W; Bellini, F; Cardani, L; Dafinei, I; Di Domizio, S; Di Vacri, M L; Gironi, L; Kosmyna, M B; Nazarenko, B P; Nisi, S; Pessina, G; Piperno, G; Pirro, S; Rusconi, C; Shekhovtsov, A N; Tomei, C; Vignati, M
2013-01-01T23:59:59.000Z
We report on the observation of the $^{151}$Eu $\\alpha$ decay to the ground state of $^{147}$Pm. We measured a half-life of T_{1/2}=(4.62$\\pm$0.95(stat.)$\\pm$0.68(syst.))$\\times 10^{18}$ y and a Q-value of 1948.9$\\pm$6.9 keV, using a 6.15 g Li$_6$Eu(BO$_3$)$_3$ crystal operated as scintillating bolometer.
Mass determination in sequential particle decay chains
Bryan Webber
2009-09-12T23:59:59.000Z
A simple method is proposed for determining the masses of new particles in collider events containing a pair of decay chains (not necessarily identical) of the form Z -> Y+1, Y -> X+2, X -> N+3, where 1,2 and 3 are visible but N is not. Initial study of a possible supersymmetric case suggests that the method can determine the four unknown masses in effectively identical chains with good accuracy from samples of a few tens of events.
False vacuum decay induced by particle collisions
Kuznetsov, A.N.; Tinyakov, P.G. [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, Moscow 117312 (Russia)] [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, Moscow 117312 (Russia)
1997-07-01T23:59:59.000Z
The semiclassical formalism for numerical calculation of the rate of tunneling transitions induced by N particles with total energy E of order or higher than the height of the barrier is developed. The formalism is applied to the induced false vacuum decay in the massive four-dimensional {minus}{lambda}{phi}{sup 4} model. The decay rate, as a function of E and N, is calculated numerically in the range 0.4{approx_lt}E/E{sub sph}{approx_lt}3.5 and 0.25{approx_lt}N/N{sub sph}{approx_lt}1.0, where E{sub sph} and N{sub sph} are the energy and the number of particles in the analogue of the sphaleron configuration. The results imply that the {ital two-particle} cross section of the false vacuum decay is exponentially suppressed at least up to energies of order 10E{sub sph}. At E{approximately}E{sub sph}, this exponential suppression is estimated as about 80{percent} of the zero energy suppression. {copyright} {ital 1997} {ital The American Physical Society}
False Vacuum Decay Induced by Particle Collisions
A. N. Kuznetsov; P. G. Tinyakov
1997-03-06T23:59:59.000Z
The semiclassical formalism for numerical calculation of the rate of tunneling transitions induced by N particles with total energy E of order or higher than the height of the barrier is developed. The formalism is applied to the induced false vacuum decay in the massive four-dimensional $-\\lambda\\phi^4$ model. The decay rate, as a function of E and N, is calculated numerically in the range $0.4\\lsim E/E_{sph}\\lsim 3.5$ and $0.25 \\lsim N/N_{sph}\\lsim 1.0$, where $E_{sph}$ and $N_{sph}$ are the energy and the number of particles in the analog of the sphaleron configuration. The results imply that the ``two-particle'' cross section of the false vacuum decay is exponentially suppressed at least up to energies of order $10 E_{sph}$. At $E\\sim E_{sph}$, this exponential suppression is estimated as about 80% of the zero energy suppression.
A background free double beta decay experiment
Ioannis Giomataris
2010-12-20T23:59:59.000Z
We present a new detection scheme for rejecting backgrounds in neutrino less double beta decay experiments. It relies on the detection of Cherenkov light emitted by electrons in the MeV region. The momentum threshold is tuned to reach a good discrimination between background and good events. We consider many detector concepts and a range of target materials. The most promising is a high-pressure 136Xe emitter for which the required energy threshold is easily adjusted. Combination of this concept and a high pressure Time Projection Chamber could provide an optimal solution. A simple and low cost effective solution is to use the Spherical Proportional Counter that provides two delayed signals from ionization and Cherenkov light. In solid-state double beta decay emitters, because of their higher density, the considered process is out of energy range. An alternative solution could be the development of double decay emitters with lower density by using for instance the aerogel technique. It is surprising that a technology used for particle identification in high-energy physics becomes a powerful tool for rejecting backgrounds in such low-energy experiments.
Delayed Nickel Decay in Gamma Ray Bursts
G. C. McLaughlin; R. A. M. J. Wijers
2002-05-19T23:59:59.000Z
Recently observed emission lines in the X-ray afterglow of gamma ray bursts suggest that iron group elements are either produced in the gamma ray burst, or are present nearby. If this material is the product of a thermonuclear burn, then such material would be expected to be rich in Nickel-56. If the nickel remains partially ionized, this prevents the electron capture reaction normally associated with the decay of Nickel-56, dramatically increasing the decay timescale. Here we examine the consequences of rapid ejection of a fraction of a solar mass of iron group material from the center of a collapsar/hypernova. The exact rate of decay then depends on the details of the ionization and therefore the ejection process. Future observations of iron, nickel and cobalt lines can be used to diagnose the origin of these elements and to better understand the astrophysical site of gamma ray bursts. In this model, the X-ray lines of these iron-group elements could be detected in suspected hypernovae that did not produce an observable gamma ray burst due to beaming.
Double beta decays of {sup 106}Cd
Suhonen, Jouni [Department of Physics, P.O. Box 35 (YFL), FI-40014 University of Jyvaeskylae (Finland)
2011-12-16T23:59:59.000Z
The two-neutrino (2{nu}2{beta}) and neutrinoless (0{nu}2{beta}) double beta decays of {sup 106}Cd are studied for the transitions to the ground state 0{sub gs}{sup +} and 0{sup +} and 2{sup +} excited states in {sup 106}Pd by using realistic many-body wave functions calculated in the framework of the quasiparticle random-phase approximation. Effective, G-matrix-derived nuclear forces are used in realistic single-particle model spaces. All the possible channels, {beta}{sup +}{beta}{sup +}, {beta}{sup +}EC, and ECEC, are discussed for both the 2{nu}2{beta} and 0{nu}2{beta} decays. The associated half-lives are computed and particular attention is devoted to the study of the detectability of the resonant neutrinoless double electron capture (R0{nu}ECEC) process in {sup 106}Cd. The calculations of the present article constitute the thus far most complete and up-to-date investigation of the double-beta-decay properties of {sup 106}Cd.
Age-dependent decay in the landscape
Winitzki, Sergei [Department of Physics, University of Heidelberg (Germany)
2008-03-15T23:59:59.000Z
The picture of the 'multiverse' arising in diverse cosmological scenarios involves transitions between metastable vacuum states. It was pointed out by Krauss and Dent that the transition rates decrease at very late times, leading to a dependence of the transition probability between vacua on the age of each vacuum region. I investigate the implications of this non-Markovian, age-dependent decay on the global structure of the spacetime in landscape scenarios. I show that the fractal dimension of the eternally inflating domain is precisely equal to 3, instead of being slightly below 3, which is the case in scenarios with purely Markovian, age-independent decay. I develop a complete description of a non-Markovian landscape in terms of a nonlocal master equation. Using this description I demonstrate by an explicit calculation that, under some technical assumptions about the landscape, the probabilistic predictions of our position in the landscape are essentially unchanged, regardless of the measure used to extract these predictions. I briefly discuss the physical plausibility of realizing non-Markovian vacuum decay in cosmology in view of the possible decoherence of the metastable quantum state.
Electron Screening and Alpha-Decay
Agatino Musumarra
2010-10-21T23:59:59.000Z
The interplay between nuclear and electromagnetic forces in astrophysical relevant reactions at very low energies is nowadays one of the major subjects of investigation in nuclear astrophysics. Puzzling results concerning the role of Electron Screening (ES) on cross sections of reactions involving light nuclei at low energy open a Pandora pot and many new questions rise on the limits and reliability of the present interpretation of the screening enhancement factor. In the present paper we discuss the simplest physical case where the ES plays an important role in order to have unambiguous determination of ES energy in a clear theoretical scenario. This is the case of alpha-decay of heavy mass nuclei. We deduce the correct sudden and adiabatic limit for such a system including the important relativistic corrections. Then we demonstrate rigorously how in this case the calculation of the sudden and the adiabatic limits leads to the same result. In order to get this result we use the Hellmann-Feynman theorem. After computing the electron screening energy for some systems we discuss the strong modifications of alpha-decay systematic due to electron screening. We conclude proposing a measurement of alpha-decay lifetime of bare nuclei in order to directly deduce ES Energy for heavy nuclei laying in the mass region around 210-240 u.
Giunti, Carlo; Laveder, Marco [INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Dipartimento di Fisica G. Galilei, Universita di Padova, and INFN, Sezione di Padova, Via F. Marzolo 8, I-35131 Padova (Italy)
2010-09-01T23:59:59.000Z
We consider the interpretation of the MiniBooNE low-energy anomaly and the gallium radioactive source experiments anomaly in terms of short-baseline electron neutrino disappearance in the framework of 3+1 four-neutrino mixing schemes. The separate fits of MiniBooNE and gallium data are highly compatible, with close best-fit values of the effective oscillation parameters {Delta}m{sup 2} and sin{sup 2}2{theta}. The combined fit gives {Delta}m{sup 2}(greater-or-similar sign)0.1 eV{sup 2} and 0.11(less-or-similar sign)sin{sup 2}2{theta}(less-or-similar sign)0.48 at 2{sigma}. We consider also the data of the Bugey and Chooz reactor antineutrino oscillation experiments and the limits on the effective electron antineutrino mass in {beta} decay obtained in the Mainz and Troitsk tritium experiments. The fit of the data of these experiments limits the value of sin{sup 2}2{theta} below 0.10 at 2{sigma}. Considering the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data as a statistical fluctuation, we perform a combined fit which gives {Delta}m{sup 2}{approx_equal}2 eV and 0.01(less-or-similar sign)sin{sup 2}2{theta}(less-or-similar sign)0.13 at 2{sigma}. Assuming a hierarchy of masses m{sub 1}, m{sub 2}, m{sub 3}<
Lepton flavor violating Higgs boson decays from massive seesaw neutrinos
Arganda, Ernesto; Curiel, Ana M.; Herrero, Maria J.; Temes, David [Departamento de Fisica Teorica, Universidad Autonoma de Madrid (Spain); Laboratoire de Physique Theorique, LAPTH (France)
2005-02-01T23:59:59.000Z
Lepton flavor violating Higgs boson decays are studied within the context of seesaw models with Majorana massive neutrinos. Two models are considered: the SM-seesaw, with the standard model particle content plus three right-handed neutrinos, and the MSSM-seesaw, with the minimal supersymmetric standard model particle content plus three right-handed neutrinos and their supersymmetric partners. The widths for these decays are derived from a full one-loop diagrammatic computation in both models, and they are analyzed numerically in terms of the seesaw parameters, namely, the Dirac and Majorana mass matrices. Several possible scenarios for these mass matrices that are compatible with neutrino data are considered. In the SM-seesaw case, very small branching ratios are found for all studied scenarios. These ratios are explained as a consequence of the decoupling behavior of the heavy right-handed neutrinos. In contrast, in the MSSM-seesaw case, sizable branching ratios are found for some of the leptonic flavor violating decays of the MSSM neutral Higgs bosons and for some choices of the seesaw matrices and MSSM parameters. The relevance of the two competing sources of lepton flavor changing interactions in the MSSM-seesaw case is also discussed. The nondecoupling behavior of the supersymmetric particles contributing in the loop diagrams is finally shown.
The Prediction of the Maximum Modes of Decay of Mesons
Ramanna, R
1999-01-01T23:59:59.000Z
In an earlier work, several properties of fundamental particles were brought together by a simple equation based on continuity and discreteness. It is shown here, that the maximum modes of decay of all fundamental particles can also be predicted without any arbitrary parameters. The method used is to break up the mean lifetimes of particles to obtain the maximum modes of decay. This is done by using a binary expansion of $\\hbar/MT$ where M is the mass of the particle and T is the mean lifetime. The agreements between that obtained from theory and experiment are remarkable. The ordering of the flavours plays an important part in understanding the reasons for this agreement. It is shown that the Zeno effect in Quantum mechanics is connected with use of the binary series.
The Prediction of the Maximum Modes of Decay of Mesons
Raja Ramanna
1999-04-27T23:59:59.000Z
In an earlier work, several properties of fundamental particles were brought together by a simple equation based on continuity and discreteness. It is shown here, that the maximum modes of decay of all fundamental particles can also be predicted without any arbitrary parameters. The method used is to break up the mean lifetimes of particles to obtain the maximum modes of decay. This is done by using a binary expansion of $\\hbar/MT$ where M is the mass of the particle and T is the mean lifetime. The agreements between that obtained from theory and experiment are remarkable. The ordering of the flavours plays an important part in understanding the reasons for this agreement. It is shown that the Zeno effect in Quantum mechanics is connected with use of the binary series.
Half-lives of Double $?^+$-decay with Two Neutrinos
Yuejiao Ren; Zhongzhou Ren
2015-01-07T23:59:59.000Z
Nuclear double $\\beta ^-$-decays with two neutrinos were observed for many years and a systematic law describing the relation between their half-lives and decay energies was also proposed recently [Phys. Rev. C89, 064603 (2014)]. However, double $\\beta ^+$-decay ($\\beta ^+\\beta^+)$ with emission of both two positrons and two neutrinos has not been observed up to date. In this article, we perform a systematic analysis on the candidates of double $\\beta ^+$-decay, based on the 2012 nuclear mass table. Eight nuclei are found to be the good candidates for double $\\beta ^+$-decay and their half-lives are predicted according to the generalization of the systematic law to double $\\beta ^+$-decay. As far as we know, there is no theoretical result on double $\\beta ^+$-decay of nucleus $^{154}Dy$ and our result is the first prediction on this nucleus. This is also the first complete research on eight double $\\beta ^+$-decay candidates based on the available data of nuclear masses. It is expected that the calculated half-lives of double $\\beta ^+$-decay in this article will be useful for future experimental search of double $\\beta ^+$-decay.
Biassoni, Pietro; /Milan U.
2009-01-22T23:59:59.000Z
In this thesis work we have measured the following upper limits at 90% of confidence level, for B meson decays (in units of 10{sup -6}), using a statistics of 465.0 x 10{sup 6} B{bar B} pairs: {Beta}(B{sup 0} {yields} {eta}K{sup 0}) < 1.6 {Beta}(B{sup 0} {yields} {eta}{eta}) < 1.4 {Beta}(B{sup 0} {yields} {eta}{prime}{eta}{prime}) < 2.1 {Beta}(B{sup 0} {yields} {eta}{phi}) < 0.52 {Beta}(B{sup 0} {yields} {eta}{omega}) < 1.6 {Beta}(B{sup 0} {yields} {eta}{prime}{phi}) < 1.2 {Beta}(B{sup 0} {yields} {eta}{prime}{omega}) < 1.7 We have no observation of any decay mode, statistical significance for our measurements is in the range 1.3-3.5 standard deviation. We have a 3.5{sigma} evidence for B {yields} {eta}{omega} and a 3.1 {sigma} evidence for B {yields} {eta}{prime}{omega}. The absence of observation of the B{sup 0} {yields} {eta}K{sup 0} open an issue related to the large difference compared to the charged mode B{sup +} {yields} {eta}K{sup +} branching fraction, which is measured to be 3.7 {+-} 0.4 {+-} 0.1 [118]. Our results represent substantial improvements of the previous ones [109, 110, 111] and are consistent with theoretical predictions. All these results were presented at Flavor Physics and CP Violation (FPCP) 2008 Conference, that took place in Taipei, Taiwan. They will be soon included into a paper to be submitted to Physical Review D. For time-dependent analysis, we have reconstructed 1820 {+-} 48 flavor-tagged B{sup 0} {yields} {eta}{prime}K{sup 0} events, using the final BABAR statistic of 467.4 x 10{sup 6} B{bar B} pairs. We use these events to measure the time-dependent asymmetry parameters S and C. We find S = 0.59 {+-} 0.08 {+-} 0.02, and C = -0.06 {+-} 0.06 {+-} 0.02. A non-zero value of C would represent a directly CP non-conserving component in B{sup 0} {yields} {eta}{prime}K{sup 0}, while S would be equal to sin2{beta} measured in B{sup 0} {yields} J/{psi}K{sub s}{sup 0} [108], a mixing-decay interference effect, provided the decay is dominated by amplitudes of a single weak phase. The new measured value of S can be considered in agreement with the expectations of the 'Standard Model', inside the experimental and theoretical uncertainties. Inconsistency of our result for S with CP conservation (S = 0) has a significance of 7.1 standard deviations (statistical and systematics included). Our result for the direct-CP violation parameter C is 0.9 standard deviations from zero (statistical and systematics included). Our results are in agreement with the previous ones [18]. Despite the statistics is only 20% larger than the one used in previous measurement, we improved of 20% the error on S and of 14% the error on C. This error is the smaller ever achieved, by both BABAR and Belle, in Time-Dependent CP Violation Parameters measurement is a b {yields} s transition.
Neutrino mixing schemes and neutrinoless double beta decay
H. V. Klapdor-Kleingrothaus; U. Sarkar
2002-02-22T23:59:59.000Z
We study the possible structure of the neutrino mass matrix taking into consideration the solar and atmospheric neutrinos and the neutrinoless double beta decay. We emphasize on mass matrices with vanishing elements. There are only a very few possibilities remaining at present. We concentrate on three generation scenarios and find that with three parameters there are few possibilities with and without any vanishing elements. For completeness we also present a five parameter four neutrino (with one sterile neutrino) mass matrix which can explain all these experiments and the LSND result.
Bulk Viscosity, Decaying Dark Matter, and the Cosmic Acceleration
James R. Wilson; Grant J. Mathews; George M. Fuller
2006-09-25T23:59:59.000Z
We discuss a cosmology in which cold dark-matter particles decay into relativistic particles. We argue that such decays could lead naturally to a bulk viscosity in the cosmic fluid. For decay lifetimes comparable to the present hubble age, this bulk viscosity enters the cosmic energy equation as an effective negative pressure. We investigate whether this negative pressure is of sufficient magnitude to account fo the observed cosmic acceleration. We show that a single decaying species in a flat, dark-matter dominated cosmology without a cosmological constant cannot reproduce the observed magnitude-redshift relation from Type Ia supernovae. However, a delayed bulk viscosity, possibly due to a cascade of decaying particles may be able to account for a significant fraction of the apparent cosmic acceleration. Possible candidate nonrelativistic particles for this scenario include sterile neutrinos or gauge-mediated decaying supersymmetric particles.
$\\beta$-decay of key titanium isotopes in stellar environment
Nabi, Jameel-Un; 10.1142/S0218301311018174
2011-01-01T23:59:59.000Z
Amongst iron regime nuclei, $\\beta$-decay rates on titanium isotopes are considered to be important during the late phases of evolution of massive stars. The key $\\beta$-decay isotopes during presupernova evolution were searched from available literature and a microscopic calculation of the decay rates were performed using the proton-neutron quasiparticle random phase approximation (pn-QRPA) theory. As per earlier simulation results electron capture and $\\beta$-decay on certain isotopes of titanium are considered to be important for the presupernova evolution of massive stars. Earlier the stellar electron capture rates and neutrino energy loss rates due to relevant titanium isotopes were presented. In this paper we finally present the $\\beta$-decay rates of key titanium isotopes in stellar environment. The results are also compared against previous calculations. The pn-QRPA $\\beta$-decay rates are bigger at high stellar temperatures and smaller at high stellar densities compared to the large scale shell model...
Neutrinoless double beta decay and QCD corrections
Namit Mahajan
2014-01-30T23:59:59.000Z
We consider one loop QCD corrections and renormalization group running of the neutrinoless double beta decay amplitude focusing on the short-range part of the amplitude (without the light neutrino exchange) and find that these corrections can be sizeable. Depending on the operator under consideration, there can be moderate to large cancellations or significant enhancements. We discuss several specific examples in this context. Such large corrections will lead to significant shifts in the half-life estimates which currently are known to be plagued with the uncertainties due to nuclear physics inputs to the physical matrix elements.
Search for ? mesons in ? lepton decay
Baringer, Philip S.
1997-02-01T23:59:59.000Z
¯m and Em the momentum and energy of the event. All charged tracks are assumed to be pions. @19# R.A. Fisher, Ann. Eugen. 7, 179 ~1936!. @20# B. Flury and H. Ridewyl, Multivariate Statistics, A Practical Approach ~New York, Chapman and Hall, 1988!. @21# S... of information on a possible four-quark state @C~1480!# with a mass 1480 MeV/c2 and JPC5122 @3,4# which decays into fp . Building on the work of Ref. @5#, Eidelman and Ivanchenko @6# estimate the branching fraction of t2!fp2n t assuming that the C~1480...
Grigorenko, L. V.; Wiser, T. D.; Mercurio, K.; Charity, R. J.; Shane, R.; Sobotka, L. G.; Elson, J. M.; Wuosmaa, A. H.; Banu, A.; McCleskey, M.; Trache, L.; Tribble, Robert E.; Zhukov, M. V.
2009-01-01T23:59:59.000Z
and, possibly, of the A = 6 isobars. DOI: 10.1103/PhysRevC.80.034602 PACS number(s): 23.50.+z, 23.20.En, 21.60.Gx, 27.20.+n I. INTRODUCTION Two-proton (2p) radioactivity was predicted by V. I. Goldansky in 1960 [1] as an exclusively quantum... in Fig. 1 that shows that the 5Li ground state (g.s.) is not fully accessible for sequential decay. Because the experimental discovery of 45Fe two-proton radioactivity in 2002 [2,3], this field has made fast progress. New cases of 2p radioactivity...
Search for the rare decay Bs0??+?-
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; Alverson, G.; et al
2010-10-01T23:59:59.000Z
We present the results of a search for the flavor changing neutral current decay B0susing 6.1 fb-1 of pp? collisions at collected by the D0 experiment at the Fermilab Tevatron Collider. The observed number of B0scandidates is consistent with background expectations. The resulting upper limit on the branching fraction is B (B0s ? ????) -8 at the 95% C.L. This limit is a factor of 2.4 better than that of the previous D0 analysis and the best limit to date.
Neutrinoless double beta decay search with the NEMO 3 experiment
Irina Nasteva; for the NEMO 3 Collaboration
2008-10-03T23:59:59.000Z
The NEMO 3 experiment searches for neutrinoless double beta decay and makes precision measurements of two-neutrino double beta decay in seven isotopes. The latest two-neutrino half-life results are presented, together with the limits on neutrinoless half-lives and the corresponding effective Majorana neutrino masses. Also given are the limits obtained on neutrinoless double beta decay mediated by Rp-violating SUSY, right-hand currents and different Majoron emission modes.
Neutrinoless double beta decay search with the NEMO 3 experiment
Nasteva, Irina [Particle Physics Group, School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL (United Kingdom)
2008-11-23T23:59:59.000Z
The NEMO 3 experiment searches for neutrinoless double beta decay and makes precision measurements of two-neutrino double beta decay in seven isotopes. The latest two-neutrino half-life results are presented, together with the limits on neutrinoless half-lives and the corresponding effective Majorana neutrino masses. Also given are the limits obtained on neutrinoless double beta decay mediated by R{sub p}-violating SUSY, right-hand currents and different Majoron emission modes.
Brane nucleation as decay of the tachyon false vacuum
Cornalba, Lorenzo; Costa, Miguel S.; Penedones, Joao [Dip. di Fisica e Sez. INFN, Universita di Roma 'Tor Vergata', Rome (Italy); Centro de Fisica do Porto e Departamento de Fisica, Faculdade de Ciencias da Universidade do Porto (Portugal); Centro de Fisica do Porto e Departamento de Fisica, Faculdade de Ciencias da Universidade do Porto (Portugal)
2005-08-15T23:59:59.000Z
It is well known that spherical D-branes are nucleated in the presence of an external RR electric field. Using the description of D-branes as solitons of the tachyon field on non-BPS D-branes, we show that the brane nucleation process can be seen as the decay of the tachyon false vacuum. This process can describe the decay of flux-branes in string theory or the decay of quintessence potentials arising in flux compactifications.
Neutrinoless Double Beta Decay in Supersymmetric Seesaw model
Tai-Fu Feng; Xue-Qian Li; Yan-An Luo
2002-09-26T23:59:59.000Z
Inspired by the recent HEIDELBERG-MOSCOW double beta decay experiment, we discuss the neutrinoless double beta decay in the supersymmetric seesaw model. Our numerical analysis indicates that we can naturally explain the data of the observed neutrinoless double beta decay, as well as that of the solar and atmospheric neutrino experiments with at least one Majorana-like sneutrino of middle energy scale in the model.
NEMO 3 double beta decay experiment: latest results
A. S. Barabash
2008-07-17T23:59:59.000Z
The double beta decay experiment NEMO~3 has been taking data since February 2003. The aim of this experiment is to search for neutrinoless decay and investigate two neutrino double beta decay in seven different enriched isotopes ($^{100}$Mo,$^{82}$Se, $^{48}$Ca, $^{96}$Zr, $^{116}$Cd, $^{130}$Te and $^{150}$Nd). After analysis of the data corresponding to 693 days, no evidence for $0\
The background in the neutrinoless double beta decay experiment GERDA
Agostini, M; Andreotti, E; Bakalyarov, A M; Balata, M; Barabanov, I; Heider, M Barnabe; Barros, N; Baudis, L; Bauer, C; Becerici-Schmidt, N; Bellotti, E; Belogurov, S; Belyaev, S T; Benato, G; Bettini, A; Bezrukov, L; Bode, T; Brudanin, V; Brugnera, R; Budjas, D; Caldwell, A; Cattadori, C; Chernogorov, A; Cossavella, F; Demidova, E V; Domula, A; Egorov, V; Falkenstein, R; Ferella, A; Freund, K; Frodyma, N; Gangapshev, A; Garfagnini, A; Gotti, C; Grabmayr, P; Gurentsov, V; Gusev, K; Guthikonda, K K; Hampel, W; Hegai, A; Heisel, M; Hemmer, S; Heusser, G; Hofmann, W; Hult, M; Inzhechik, L V; Ioannucci, L; Csathy, J Janicsko; Jochum, J; Junker, M; Kihm, T; Kirpichnikov, I V; Kirsch, A; Klimenko, A; Knoepfle, K T; Kochetov, O; Kornoukhov, V N; Kuzminov, V V; Laubenstein, M; Lazzaro, A; Lebedev, V I; Lehnert, B; Liao, H Y; Lindner, M; Lippi, I; Liu, X; Lubashevskiy, A; Lubsandorzhiev, B; Lutter, G; Macolino, C; Machado, A A; Majorovits, B; Maneschg, W; Nemchenok, I; Nisi, S; O'Shaughnessy, C; Palioselitis, D; Pandola, L; Pelczar, K; Pessina, G; Pullia, A; Riboldi, S; Sada, C; Salathe, M; Schmitt, C; Schreiner, J; Schulz, O; Schwingenheuer, B; Schoenert, S; Shevchik, E; Shirchenko, M; Simgen, H; Smolnikov, A; Stanco, L; Strecker, H; Tarka, M; Ur, C A; Vasenko, A A; Volynets, O; von Sturm, K; Wagner, V; Walter, M; Wegmann, A; Wester, T; Wojcik, M; Yanovich, E; Zavarise, P; Zhitnikov, I; Zhukov, S V; Zinatulina, D; Zuber, K; Zuzel, G
2014-01-01T23:59:59.000Z
The GERmanium Detector Array (GERDA) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double beta decay of 76Ge. The signature of the signal is a monoenergetic peak at 2039 keV, the Q-value of the decay, Q_bb. To avoid bias in the signal search, the present analysis does not consider all those events, that fall in a 40 keV wide region centered around Q_bb. The main parameters needed for the neutrinoless double beta decay analysis are described. A background model was developed to describe the observed energy spectrum. The model contains several contributions, that are expected on the basis of material screening or that are established by the observation of characteristic structures in the energy spectrum. The model predicts a flat energy spectrum for the blinding window around Q_bb with a background index ranging from 17.6 to 23.8*10^{-3} counts/(keV kg yr). A part of the data not considered before has been used to test if the predictions of the background model...
Spectroscopy and Decay of $B$ Hadrons at the Tevatron
Paulini, Manfred
2007-02-01T23:59:59.000Z
The authors review recent results on heavy quark physics focusing on Run II measurements of B hadron spectroscopy and decay at the Tevatron. A wealth of new B physics measurements from CDF and D0 has been available. These include the spectroscopy of excited B states (B**, B**{sub s}) and the observation of the {Sigma}{sub b} baryon. The discussion of the decays of B hadrons and measurements of branching fractions focuses on charmless two-body decays of B {yields} h{sup +}h{sup -}. They report several new B{sub s}{sup 0} and {Lambda}{sub b}{sup 0} decay channels.
Exploring the Neutrinoless Double Beta Decay in the Inverted...
Office of Scientific and Technical Information (OSTI)
Exploring the Neutrinoless Double Beta Decay in the Inverted Neutrino Hierarchy with Bolometric Detectors Citation Details In-Document Search Title: Exploring the Neutrinoless...
Pion and muon decays beyond the standard model
Herczeg, P.
1988-01-01T23:59:59.000Z
We review and discuss the information provided by charged pion and muon decays on physics beyond the minimal standard model. 109 refs., 3 tabs.
Searches for Leptonic B Decays at BaBar
Nelson, Silke; /SLAC
2012-04-25T23:59:59.000Z
Measurements of the branching fractions of purely leptonic decays of B-mesons translate into constraints in the plane of the charged Higgs mass versus tan {beta} which are relatively insensitive to the particular theoretical model. Using the full BABAR dataset of 450 million B-decays we search for these decays. No significant signal is found in the decays into electrons or muons and we set upper limits on the branching fractions of the order of a 10{sup -6} at 90% confidence level. We measure the branching fraction of B {yields} {tau}{mu} to be (1.7 {+-} 0.6) x 10{sup -4}.
75 years of double beta decay: yesterday, today and tomorrow
A. S. Barabash
2011-01-24T23:59:59.000Z
In this report I will briefly review the motivation and history of double beta decay search since the first consideration of two neutrino process (2$\\beta(2\
Alpha-nucleus potential for alpha-decay and sub-barrier fusion
V. Yu. Denisov; H. Ikezoe
2005-10-27T23:59:59.000Z
The set of parameters for alpha-nucleus potential is derived by using the data for both the alpha-decay half-lives and the fusion cross-sections around the barrier for reactions alpha+40Ca, alpha+59Co, alpha+208Pb. The alpha-decay half-lives are obtained in the framework of a cluster model using the WKB approximation. The evaluated alpha-decay half-lives and the fusion cross-sections agreed well with the data. Fusion reactions between alpha-particle and heavy nuclei can be used for both the formation of very heavy nuclei and spectroscopic studies of the formed compound nuclei.
Electrons from Muon Decay in Bound State
Rashid M. Djilkibaev; Rostislav V. Konoplich
2009-02-12T23:59:59.000Z
We present results of a study of the muon decay in orbit (DIO) contribution to the signal region of muon - electron conversion. Electrons from DIO are the dominant source of background for muon - electron conversion experiments because the endpoint of DIO electrons is the same as the energy of electrons from elastic muon - electron conversion. The probability of DIO contribution to the signal region was considered for a tracker with Gaussian resolution function and with a realistic resolution function obtained in the application of pattern recognition and momentum reconstruction Kalman filter based procedure to GEANT simulated DIO events. It is found that the existence of non Gaussian tails in the realistic resolution function does not lead to a significant increase in DIO contribution to the signal region. The probability of DIO contribution to the calorimeter signal was studied in dependence on the resolution, assuming a Gaussian resolution function of calorimeter. In this study the geometrical acceptance played an important role, suppressing DIO contribution of the intermediate range electrons from muon decay in orbit.
Bounds on R-parity violating supersymmetric couplings from leptonic and semileptonic meson decays
Dreiner, H. K.; Kraemer, M.; O'Leary, Ben [Physikalisches Institut der Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Institut fuer Theoretische Physik E, RWTH Aachen, 52056 Aachen (Germany); S.U.P.A., School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom) and Institut fuer Theoretische Physik E, RWTH Aachen, 52056 Aachen (Germany)
2007-06-01T23:59:59.000Z
We present a comprehensive update of the bounds on R-parity violating supersymmetric couplings from lepton-flavor- and lepton-number-violating decay processes. We consider {tau} and {mu} decays as well as leptonic and semileptonic decays of mesons. We present several new bounds resulting from {tau}, {eta}, and kaon decays and correct some results in the literature concerning B meson decays.
Search for CPV in tau decays. Yurii Maravin SMU/CLEO
Search for CPV in tau decays. Search for CPV in tau decays. Yurii Maravin, SMU/CLEO Yurii Maravin SMU/CLEO #12; Search for CPV in tau decays. Motivation Search for the CP violation is interesting. Search for CP violation in lepton decays. Yurii Maravin SMU/CLEO #12; Search for CPV in tau decays. Gauge
CP Violation in B->eta'K0 and Status of SU(3)-related Decays
J. G. Smith
2007-03-19T23:59:59.000Z
We present measurements from Belle and BABAR of the time-dependent CP-violation parameters S and C in B->eta'K0 decays. Both experiments observe mixing-induced CP violation with a significance of more than 5 standard deviations in this b-> s penguin dominated mode. We also compare with theoretical expectations and discuss the latest results for SU(3)-related decays which are useful for obtaining bounds on the expected values of S and C.
Graphical Representation of CP Violation Effects in Neutrinoless Double Beta Decay
K. Matsuda; N. Takeda; T. Fukuyama; H. Nishiura
2000-07-21T23:59:59.000Z
We illustrate the graphical method that gives the constraints on the parameters appearing in the neutrino oscillation experiments and the neutrinoless double beta decay. This method is applicable in three and four generations. Though this method is valid for more general case, we examine explicitly the cases in which the CP violating factors take $\\pm 1$ or $\\pm i$ in the neutrinoless double beta decay for illustrative clearance. We also discuss some mass matrix models which lead to the above CP violating factors.
Non-unitary neutrino propagation from neutrino decay
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Berryman, Jeffrey M.; de Gouvêa, André; Hernández, Daniel; Oliveira, Roberto L.N.
2015-03-01T23:59:59.000Z
Neutrino propagation in space–time is not constrained to be unitary if very light states – lighter than the active neutrinos – exist into which neutrinos may decay. If this is the case, neutrino flavor-change is governed by a handful of extra mixing and “oscillation” parameters, including new sources of CP-invariance violation. We compute the transition probabilities in the two- and three-flavor scenarios and discuss the different phenomenological consequences of the new physics. These are qualitatively different from other sources of unitarity violation discussed in the literature.
Leptonic Decays of the Charged B Meson
Corwin, Luke A.; /Ohio State U.; ,
2010-06-11T23:59:59.000Z
The authors present a search for the decay B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}} ({ell} = {tau}, {mu}, or e) in (458.9 {+-} 5.1) x 10{sup 6} {Upsilon}(4S) decays recorded with the BABAR detector at the SLAC PEP-II B-Factory. A sample of events with one reconstructed exclusive semi-leptonic B decay (B{sup -} {yields} D{sup 0}{ell}{sup -}{bar {nu}}X) is selected, and in the recoil a search for B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}} signal is performed. The {tau} is identified in the following channels: {tau}{sup +} {yields} e{sup +}{nu}{sub e}{bar {nu}}{sub {tau}}, {tau}{sup +} {yields} {mu}{sup +}{nu}{sub {mu}}{bar {nu}}{sub {tau}}, {tau}{sup +} {yields} {pi}{sup +}{bar {nu}}{sub {tau}}, and {tau}{sup +} {yields} {pi}{sup +}{pi}{sup 0}{bar {nu}}{sub {tau}}. The analysis strategy and the statistical procedure is set up for branching fraction extraction or upper limit determination. They determine from the dataset a preliminary measurement of {Beta}(B{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) = (1.8 {+-} 0.8 {+-} 0.1) x 10{sup -4}, which excludes zero at 2.4{sigma}, and f{sub B} = 255 {+-} 58 MeV. Combination with the hadronically tagged measurement yields {Beta}(B{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) = (1.8 {+-} 0.6) x 10{sup -4}. They also set preliminary limits on the branching fractions at {Beta}(B{sup +} {yields} e{sup +}{nu}{sub e}) < 7.7 x 10{sup -6} (90% C.L.), {Beta}(B{sup +} {yields} {mu}{sup +}{nu}{sub {mu}}) < 11 x 10{sup -6} (90% C.L.), and {Beta}(B{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) < 3.2 x 10{sup -4} (90% C.L.).
Neutrinos from Decaying Muons, Pions, Kaons and Neutrons in Gamma Ray Bursts
Reetanjali Moharana; Nayantara Gupta
2012-05-27T23:59:59.000Z
In the internal shock model of gamma ray bursts ultrahigh energy muons, pions, neutrons and kaons are likely to be produced in the interactions of shock accelerated relativistic protons with low energy photons (KeV-MeV). These particles subsequently decay to high energy neutrinos/antineutrinos and other secondaries. In the high internal magnetic fields of gamma ray bursts, the ultrahigh energy charged particles ($\\mu^+$, $\\pi^+$, $K^+$) lose energy significantly due to synchrotron radiations before decaying into secondary high energy neutrinos and antineutrinos. The relativistic neutrons decay to high energy antineutrinos, protons and electrons. We have calculated the total neutrino flux (neutrino and antineutrino) considering the decay channels of ultrahigh energy muons, pions, neutrons and kaons. We have shown that the total neutrino flux generated in neutron decay can be higher than that produced in $\\mu^+$ and $\\pi^+$ decay. The charged kaons being heavier than pions, lose energy slowly and their secondary total neutrino flux is more than that from muons and pions at very high energy. Our detailed calculations on secondary particle production in $p\\gamma$ interactions give the total neutrino fluxes and their flavour ratios expected on earth. Depending on the values of the parameters (luminosity, Lorentz factor, variability time, spectral indices and break energy in the photon spectrum) of a gamma ray burst the contributions to the total neutrino flux from the decay of different particles (muon, pion, neutron and kaon) may vary and they would also be reflected on the neutrino flavour ratios.
Significant neutrinoless double beta decay with quasi-Dirac neutrinos
Pei-Hong Gu
2012-09-13T23:59:59.000Z
A significant signal of neutrinoless double beta decay can be consistent with the existence of light quasi-Dirac neutrinos. To demonstrate this possibility, we consider a realistic model where the neutrino masses and the neutrinoless double beta decay can be simultaneously generated after a Peccei-Quinn symmetry breaking.
Neutrinoless double-{beta} decay: Status and future
Bilenky, S. M. [Joint Institute for Nuclear Research (Russian Federation)], E-mail: bilenky@he.sissa.it
2006-12-15T23:59:59.000Z
A brief summary of the status of neutrino masses, mixing, and oscillations is presented. Neutrinoless double {beta} decay is considered. Predictions for the effective Majorana mass are reviewed. A possible test of the calculations of nuclear matrix elements of the 0{nu}{beta}{beta} decay is proposed.
Scaling Factor Inconsistencies in Neutrinoless Double Beta Decay
S. Cowell
2005-12-05T23:59:59.000Z
The modern theory of neutrinoless double beta decay includes a scaling factor that has often been treated inconsistently in the literature. The nuclear contribution to the decay half life can be suppressed by 15-20% when scaling factors are mismatched. Correspondingly, $$ is overestimated.
Scaling factor inconsistencies in neutrinoless double beta decay
Cowell, S. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2006-02-15T23:59:59.000Z
The modern theory of neutrinoless double beta decay includes a scaling factor that has often been treated inconsistently in the literature. The nuclear contribution to the decay half-life can be suppressed by 15%-20% when scaling factors are mismatched. Correspondingly,
False vacuum decay in a brane world cosmological model
Michal Demetrian
2006-01-12T23:59:59.000Z
The false vacuum decay in a brane world model is studied in this work. We investigate the vacuum decay via the Coleman-de Luccia instanton, derive explicit approximative expressions for the Coleman-de Luccia instanton which is close to a Hawking-Moss instanton and compare the results with those already obtained within Einstein's theory of relativity.
Current Status of Nucleon Decay Searches with Super-Kamiokande
Brett Viren
1999-03-16T23:59:59.000Z
Evidence for Nucleon Decay has yet to be observed. Current results from the observation of a 45 kton-year exposure of Super-Kamiokande and lifetime limits for nucleons to decay via lepton + pion, lepton + eta and lepton + kaon modes are presented.
Phenomenology of some rare and forbidden. eta. -decays
Herczeg, P.
1990-01-01T23:59:59.000Z
We discuss the contribution from possible new physics to the decays {eta} {yields} {mu}{sup +}{mu}{sup {minus}}, {eta} {yields} e{sup +}e{sup {minus}}, {eta} {yields} {mu}e and {eta} {pi}{mu}e, and assess the sensitivities required for experimental studies of these decays to extend our knowledge about the new interactions. 61 refs.
Complete three-loop QCD corrections to the decay H -> ??
P. Maierhöfer; P. Marquard
2012-12-26T23:59:59.000Z
We present the result for the three-loop singlet QCD corrections to the decay of a Higgs boson into two photons and improve the calculation for the non-singlet case. With the new result presented, the decay width Gamma(H -> \\gamma \\gamma) is completely known at O(G_F \\alpha ^2 \\alpha_s^2, G_F \\alpha ^3).
Patterns in Offender Distance Decay and the Geographic Profiling Problem.
O'Leary, Michael
Patterns in Offender Distance Decay and the Geographic Profiling Problem. Mike O'Leary Towson University 2010 Fall Western Section Meeting Los Angeles, CA October 9-10, 2010 Mike O'Leary (Towson Department for his assistance. Mike O'Leary (Towson University) Offender Distance Decay October 9, 2010 2
Patterns in Offender Distance Decay and the Geographic Profiling Problem.
O'Leary, Michael
Patterns in Offender Distance Decay and the Geographic Profiling Problem. Mike O'Leary Towson University 2011 Crime Mapping Conference Miami, FL October 19-21, 2011 Mike O'Leary (Towson University Department for his assistance. Mike O'Leary (Towson University) Offender Distance Decay October 21, 2011 2
Effect of $?$--$?'$ mixing on $D \\to PV$ decays
Bhubanjyoti Bhattacharya; Jonathan L. Rosner
2010-07-08T23:59:59.000Z
Charmed meson decays to a light pseudoscalar ($P$) and light vector ($V$) meson are analyzed taking account of $\\eta$--$\\eta'$ mixing. A frequently-used octet-singlet mixing angle of $19.5^\\circ$ is compared with a value of $11.7^\\circ$ favored by a recent analysis of $D \\to PP$ decays.
Decays of Lowest T=2 State in Ti-44
Freedman, S. J.; Gagliardi, Carl A.; Oothoudt, M. A.; Nero, A. V.; Roberston, R. G. H.; Zutavern, F. J.; Adelberger, E. G.; McDonald, A. B.
1978-01-01T23:59:59.000Z
The decay of C-10 excited states to the 2p+2 alpha exit channel has been studied using an E/A=10.7 MeV C-10 beam inelastically scattered from a Be-9 target. Levels associated with two-proton decay to the ground state of ...
Distribution of ranks of ?-decay half-lives
Juan Miguel Campanario
2010-11-21T23:59:59.000Z
I studied the distribution of ranks of values of 2949 {\\beta}-decay half-lives according to an empirical beta law with two exponents. {\\beta}-decay half-life ranks showed good fit to a beta function with two exponents.
Mass Measurement Using Energy Spectra in Three-body Decays
Agashe, Kaustubh; Kim, Doojin; Wardlow, Kyle
2015-01-01T23:59:59.000Z
In previous works we have demonstrated how the energy distribution of massless decay products in two body decays can be used to measure the mass of decaying particles. In this work we show how such results can be generalized to the case of multi-body decays. The key ideas that allow us to deal with multi-body final states are an extension of our previous results to the case of massive decay products and the factorization of the multi-body phase space. The mass measurement strategy that we propose is distinct from alternative methods because it does not require an accurate reconstruction of the entire event, as it does not involve, for instance, the missing transverse momentum, but rather requires measuring only the visible decay products of the decay of interest. To demonstrate the general strategy, we study a supersymmetric model wherein pair-produced gluinos each decay to a stable neutralino and a bottom quark-antiquark pair via an off-shell bottom squark. The combinatorial background stemming from the indi...
One Year of Evidence for Neutrinoless Double Beta Decay
H. V. Klapdor-Kleingrothaus
2003-02-26T23:59:59.000Z
The present experimental status in the search for neutrinoless double beta decay is reviewed, with emphasis on the first indication for neutrinoless double beta decay found in the HEIDELBERG-MOSCOW experiment, giving first evidence for lepton number violation and a Majorana nature of the neutrinos. Future perspectives of the field are briefly outlined.
Correlated two-proton decay from (10)C
Mercurio, K.; Charity, R. J.; Shane, R.; Sobotka, L. G.; Elson, J. M.; Famiano, M.; Wuosmaa, A. H.; Banu, A.; Fu, C.; Trache, L.; Tribble, Robert E.; Mukhamedzhanov, A. M.
2008-01-01T23:59:59.000Z
and for a newly found level at E* = 8.4 MeV. A state at E* = 6.57 MeV is shown to undergo two-proton decay to (8)Be(g.s.) with strong p-p correlations consistent with the (1)S phase shift. Based on the lack of such correlations for other two-proton decays...
High precision measurements of Na-26 beta(-) decay
Grinyer, GF; Svensson, CE; Andreoiu, C.; Andreyev, AN; Austin, RAE; Ball, GC; Chakrawarthy, RS; Finlay, P.; Garrett, PE; Hackman, G.; Hardy, John C.; Hyland, B.; Iacob, VE; Koopmans, KA; Kulp, WD; Leslie, JR; Macdonald, JA; Morton, AC; Ormand, WE; Osborne, CJ; Pearson, CJ; Phillips, AA; Sarazin, F.; Schumaker, MA; Scraggs, HC; Schwarzenberg, J.; Smith, MB; Valiente-Dobon, JJ; Waddington, JC; Wood, JL; Zganjar, EF.
2005-01-01T23:59:59.000Z
High-precision measurements of the half-life and beta-branching ratios for the beta(-) decay of Na-26 to Mg-26 have been measured in beta-counting and gamma-decay experiments, respectively. A 4 pi proportional counter and fast tape transport system...
Double Beta Decay and the Absolute Neutrino Mass Scale
Carlo Giunti
2003-08-20T23:59:59.000Z
After a short review of the current status of three-neutrino mixing, the implications for the values of neutrino masses are discussed. The bounds on the absolute scale of neutrino masses from Tritium beta-decay and cosmological data are reviewed. Finally, we discuss the implications of three-neutrino mixing for neutrinoless double-beta decay.
Double beta decay to the excited states: experimental review
A. S. Barabash
2007-10-11T23:59:59.000Z
A brief review on double beta decay to excited states of daughter nuclei is given. The ECEC(ov) transision to the excited states are discussed in association with a possible enhancement of the decay rate by several orders of magnitude.
Neutrinoless Double Beta Decay with SNO+
J. Hartnell; for the SNO+ collaboration
2012-01-30T23:59:59.000Z
SNO+ will search for neutrinoless double beta decay by loading 780 tonnes of linear alkylbenzene liquid scintillator with O(tonne) of neodymium. Using natural Nd at 0.1% loading will provide 43.7 kg of 150Nd given its 5.6% abundance and allow the experiment to reach a sensitivity to the effective neutrino mass of 100-200 meV at 90% C.L in a 3 year run. The SNO+ detector has ultra low backgrounds with 7000 tonnes of water shielding and self-shielding of the scintillator. Distillation and several other purification techniques will be used with the aim of achieving Borexino levels of backgrounds. The experiment is fully funded and data taking with light-water will commence in 2012 with scintillator data following in 2013.
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan
1996-10-01T23:59:59.000Z
Collaboration! ~Received 16 April 1996! Using data taken with the CLEO II detector, we have studied the decays of the D0 to K1K2, K0K¯0, KS 0KS 0KS 0 , KS 0KS 0 p 0 , K1K2p0. We present significantly improved results for B(D0!K1K2)5(0.454 60.02860.035)%, B(D0!K0... K¯0)5(0.05460.01260.010)%, and B(D0!KS0KS0KS0)5(0.07460.010 60.015)%, where the first errors are statistical and the second errors are the estimate of our systematic uncertainty. We also present a new upper limit B(D0!KS0KS0p0),0.059% at the 90...
On bulk viscosity and moduli decay
M. Laine
2010-11-21T23:59:59.000Z
This pedagogically intended lecture, one of four under the header "Basics of thermal QCD", reviews an interesting relationship, originally pointed out by Bodeker, that exists between the bulk viscosity of Yang-Mills theory (of possible relevance to the hydrodynamics of heavy ion collision experiments) and the decay rate of scalar fields coupled very weakly to a heat bath (appearing in some particle physics inspired cosmological scenarios). This topic serves, furthermore, as a platform on which a number of generic thermal field theory concepts are illustrated. The other three lectures (on the QCD equation of state and the rates of elastic as well as inelastic processes experienced by heavy quarks) are recapitulated in brief encyclopedic form.
Robust quantum searching with spontaneously decaying qubits
Robert J. C. Spreeuw; Tom W. Hijmans
2007-06-29T23:59:59.000Z
We present a modification of the standard single-item quantum search procedure that acquires robustness from spontaneous decay of the qubits. This damps the usual oscillation of populations, driving the system to a steady state with a strongly enhanced population of the solution. Numerical evaluation of the steady state was performed for up to 36 qubits. The huge size of the state space in our analysis is dealt with by exploiting a symmetry in the master equation that reduces the scaling of computer resources from exponential to polynomial. Based on these results we estimate that an error-free solution can be retrieved from the steady state after O(log log N) repetitions, with near-unit probability. This brings the overall scaling to O(sqrt{N} log log N), only slightly worse than for the ideal quantum case.
Large invisible decay of a Higgs boson to neutrinos
Seto, Osamu
2015-01-01T23:59:59.000Z
We show that the standard model (SM)-like Higgs boson may decay into neutrinos with a sizable decay branching ratio in one well-known two Higgs doublet model, so-called neutrinophilic Higgs model. This could happen if the mass of the lighter extra neutral Higgs boson is smaller than one half of the SM-like Higgs boson mass. The definite prediction of this scenario is that the rate of the SM-like Higgs boson decay into diphoton normalized by the SM value is about 0.9. In the case that a neutrino is Majorana particle, a displaced vertex of right-handed neutrino decay would be additionally observed. This example indicates that a large invisible Higgs boson decay could be irrelevant to dark matter.
GravitinoPack and decays of supersymmetric metastable particles
Eberl, Helmut
2015-01-01T23:59:59.000Z
We present the package GravitinoPack that calculates the two- and three-body decays of unstable supersymmetric particles involving the gravitino in the final or initial state. In a previous paper, we already showed results for the gravitino decays into two and three particles. In this paper, we incorporate the processes where an unstable neutralino, stau or stop decays into a gravitino and Standard Model particles. This is the case in gravitino dark matter supersymmetric models, where the gravitino is the lightest SUSY particle. We give instructions for the installation and the use of the package. In the numerical analysis, we discuss various MSSM scenarios. We show that the calculation of all the decay channels and the three-body decay branching ratios is essential for the accurate application of cosmological bounds on these models.
Test of SU(3) Symmetry in Hyperon Semileptonic Decays
T. N. Pham
2014-09-22T23:59:59.000Z
Existing analyzes of baryon semileptonic decays indicate the presence of a small SU(3) symmetry breaking in hyperon semileptonic decays, but to provide evidence for SU(3) symmetry breaking, one would need a relation similar to the Gell-Mann--Okubo (GMO) baryon mass formula which is satisfied to a few percents, showing evidence for a small SU(3) symmetry breaking effect in the GMO mass formula. In this talk, I would like to present a similar GMO relation obtained in a recent work for hyperon semileptonic decay axial vector current matrix elements. Using these generalized GMO relations for the measured axial vector current to vector current form factor ratios, it is shown that SU(3) symmetry breaking in hyperon semileptonic decays is of $5-11%$ and confirms the validity of the Cabibbo model for hyperon semi-leptonic decays.
Dark radiation from particle decay: cosmological constraints and opportunities
Hasenkamp, Jasper; Kersten, Jörn, E-mail: Jasper.Hasenkamp@desy.de, E-mail: Joern.Kersten@desy.de [II. Institute for Theoretical Physics, University of Hamburg, 22761 Hamburg (Germany)
2013-08-01T23:59:59.000Z
We study particle decay as the origin of dark radiation. After elaborating general properties and useful parametrisations we provide model-independent and easy-to-use constraints from nucleosynthesis, the cosmic microwave background and structure formation. Bounds on branching ratios and mass hierarchies depend in a unique way on the time of decay. We demonstrate their power to exclude well-motivated scenarios taking the example of the lightest ordinary sparticle decaying into the gravitino. We point out signatures and opportunities in cosmological observations and structure formation. For example, if there are two dark decay modes, dark radiation and the observed dark matter with adjustable free-streaming can originate from the same decaying particle, solving small-scale problems of structure formation. Hot dark matter mimicking a neutrino mass scale as deduced from cosmological observations can arise and possibly be distinguished after a discovery. Our results can be used as a guideline for model building.
Neutrinoless Double Beta Decay in Gauge Theories
J. D. Vergados
1999-07-12T23:59:59.000Z
Neutrinoless double beta decay is a very important process both from the particle and nuclear physics point of view. Its observation will severely constrain the existing models and signal that the neutrinos are massive Majorana particles. From the elementary particle point of view it pops up in almost every model. In addition to the traditional mechanisms, like the neutrino mass, the admixture of right handed currents etc, it may occur due to the R-parity violating supersymmetric (SUSY) interactions. From the nuclear physics point of view it is challenging, because: 1) The relevant nuclei have complicated nuclear structure. 2) The energetically allowed transitions are exhaust a small part of all the strength. 3) One must cope with the short distance behavior of the transition operators, especially when the intermediate particles are heavy (eg in SUSY models). Thus novel effects, like the double beta decay of pions in flight between nucleons, have to be considered. 4) The intermediate momenta involved are about 100 MeV. Thus one has to take into account possible momentum dependent terms in the nucleon current. We find that, for the mass mechanism, such modifications of the nucleon current for light neutrinos reduce the nuclear matrix elements by about 25 per cent, almost regardless of the nuclear model. In the case of heavy neutrinos the effect is much larger and model dependent. Taking the above effects into account, the available nuclear matrix elements for the experimentally interesting nuclei A = 76, 82, 96, 100, 116, 128, 130, 136 and 150 and the experimental limits on the life times we have extracted new stringent limits on the average neutrino mass and on the R-parity violating coupling for various SUSY models.
Goswami, Srubabati [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany); Rodejohann, Werner [Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)
2006-06-01T23:59:59.000Z
We analyze the constraints on neutrino mass spectra with extra sterile neutrinos as implied by the LSND experiment. The various mass related observables in neutrinoless double beta decay, tritium beta decay and cosmology are discussed. Both neutrino oscillation results as well as recent cosmological neutrino mass bounds are taken into account. We find that some of the allowed mass patterns are severely restricted by the current constraints, in particular, by the cosmological constraints on the total sum of neutrino masses and by the nonmaximality of the solar neutrino mixing angle. Furthermore, we estimate the form of the four neutrino mass matrices and also comment on the situation in scenarios with two additional sterile neutrinos.
Srubabati Goswami; Werner Rodejohann
2006-05-18T23:59:59.000Z
We analyze the constraints on neutrino mass spectra with extra sterile neutrinos as implied by the LSND experiment. The various mass related observables in neutrinoless double beta decay, tritium beta decay and cosmology are discussed. Both neutrino oscillation results as well as recent cosmological neutrino mass bounds are taken into account. We find that some of the allowed mass patterns are severely restricted by the current constraints, in particular by the cosmological constraints on the total sum of neutrino masses and by the non-maximality of the solar neutrino mixing angle. Furthermore, we estimate the form of the four neutrino mass matrices and also comment on the situation in scenarios with two additional sterile neutrinos.
Artusa, D. R.
2014-01-01T23:59:59.000Z
Exploring the Neutrinoless Double Beta Decay in the InvertedC. Giunti, Neutrinoless double-beta decay. A brief review,el- ements for neutrinoless double-beta decay and double-
First results on neutrinoless double beta decay of Te-130 with the calorimetric cuoricino experiment
2003-01-01T23:59:59.000Z
Results on Neutrinoless Double Beta Decay of 130 Te with theEvidence for Neutrinoless Double Beta Decay” arXiv:hep-on “Evidence for neutrinoless double beta decay”- arXiv:hep-
Neutrinoless Double Beta Decay and Future Neutrino Oscillation Precision Experiments
S. Choubey; W. Rodejohann
2005-07-25T23:59:59.000Z
We discuss to what extent future precision measurements of neutrino mixing observables will influence the information we can draw from a measurement of (or an improved limit on) neutrinoless double beta decay. Whereas the Delta m^2 corresponding to solar and atmospheric neutrino oscillations are expected to be known with good precision, the parameter theta_{12} will govern large part of the uncertainty. We focus in particular on the possibility of distinguishing the neutrino mass hierarchies and on setting a limit on the neutrino mass. We give the largest allowed values of the neutrino masses which allow to distinguish the normal from the inverted hierarchy. All aspects are discussed as a function of the uncertainty stemming from the involved nuclear matrix elements. The implications of a vanishing, or extremely small, effective mass are also investigated. By giving a large list of possible neutrino mass matrices and their predictions for the observables, we finally explore how a measurement of (or an improved limit on) neutrinoless double beta decay can help to identify the neutrino mass matrix if more precise values of the relevant parameters are known.
Neutrinoless double beta decay and future neutrino oscillation precision experiments
Choubey, Sandhya [Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Rodejohann, Werner [Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)
2005-08-01T23:59:59.000Z
We discuss to what extent future precision measurements of neutrino mixing observables will influence the information we can draw from a measurement of (or an improved limit on) neutrinoless double beta decay. Whereas the {delta}m{sup 2} corresponding to solar and atmospheric neutrino oscillations are expected to be known with good precision, the parameter {theta}{sub 12} will govern a large part of the uncertainty. We focus, in particular, on the possibility of distinguishing the neutrino mass hierarchies and on setting a limit on the neutrino mass. We give the largest allowed values of the neutrino masses which allow to distinguish the normal from the inverted hierarchy. All aspects are discussed as a function of the uncertainty stemming from the involved nuclear matrix elements. The implications of a vanishing, or extremely small, effective mass are also investigated. By giving a large list of possible neutrino mass matrices and their predictions for the observables, we finally explore how a measurement of (or an improved limit on) neutrinoless double beta decay can help to identify the neutrino mass matrix if more precise values of the relevant parameters are known.
Gamma-ray burst spectrum with decaying magnetic field
Zhao, Xiaohong; Bai, Jinming [Yunnan Observatory, Chinese Academy of Sciences, P.O. Box 110, 650011 Kunming (China); Li, Zhuo [Department of Astronomy and Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Liu, Xuewen; Zhang, Bin-bin; Mészáros, Peter, E-mail: zhaoxh@ynao.ac.cn, E-mail: zhuo.li@pku.edu.cn [Department of Astronomy and Astrophysics and Department of Physics, The Pennsylvania State University, University Park, PA 16802 (United States)
2014-01-01T23:59:59.000Z
In the internal shock model for gamma-ray bursts (GRBs), the synchrotron spectrum from the fast cooling electrons in a homogeneous downstream magnetic field (MF) is too soft to produce the low-energy slope of GRB spectra. However, the MF may decay downstream with distance from the shock front. Here we show that the synchrotron spectrum becomes harder if electrons undergo synchrotron and inverse-Compton cooling in a decaying MF. To reconcile this with the typical GRB spectrum with low-energy slope ?F {sub ?}??, the postshock MF decay time must be comparable to the cooling time of the bulk electrons (corresponding to a MF decaying length typically of ?10{sup 5} skin depths); that the inverse-Compton cooling should dominate synchrotron cooling after the MF decay time; and/or that the MF decays with comoving time roughly as B?t {sup –1.5}. An internal shock synchrotron model with a decaying MF can account for the majority of GRBs with low-energy slopes not harder than ?{sup 4/3}.
The case for three-body decaying dark matter
Cheng, Hsin-Chia [Department of Physics, University of California, Davis, CA 95616 (United States); Huang, Wei-Chih [SISSA and INFN — Sezione di Trieste, Via Bonomea 265, 34136 Trieste (Italy); Low, Ian; Shaughnessy, Gabe, E-mail: cheng@physics.ucdavis.edu, E-mail: whuang@sissa.it, E-mail: ilow@northwestern.edu, E-mail: shaughnessy@wisc.edu [High Energy Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)
2013-01-01T23:59:59.000Z
Fermi-LAT has confirmed the excess in cosmic positron fraction observed by PAMELA, which could be explained by dark matter annihilating or decaying in the center of the galaxy. Most existing models postulate that the dark matter annihilates or decays into final states with two or four leptons, which would produce diffuse gamma ray emissions that are in tension with data measured by Fermi-LAT. We point out that the tension could be alleviated if the dark matter decays into three-body final states with a pair of leptons and a missing particle. Using the goldstino decay in a certain class of supersymmetric theories as a prime example, we demonstrate that simultaneous fits to the total e{sup +}+e{sup ?} and the fractional e{sup +}/e{sup ?} fluxes from Fermi-LAT and PAMELA could be achieved for a 2 TeV parent particle and a 1 TeV missing particle, without being constrained by gamma-ray measurements. By studying different effective operators giving rise to the dark matter decay, we show that this feature is generic for three-body decaying dark matter containing a missing particle. Constraints on the hadronic decay widths from the cosmic anti-proton spectra are also discussed.
Status and prospects of searches for neutrinoless double beta decay
Bernhard Schwingenheuer
2012-10-28T23:59:59.000Z
The simultaneous beta decay of two neutrons in a nucleus without the emission of neutrinos (called neutrinoless double beta decay) is a lepton number violating process which is not allowed in the Standard Model of particle physics. More than a dozen experiments using different candidate isotopes and a variety of detection techniques are searching for this decay. Some (EXO-200, Kamland-Zen, GERDA) started to take data recently. EXO and Kamland-Zen have reported first limits of the half life $T_{1/2}^{0\
Empirical Survey of Neutrinoless Double Beta Decay Matrix Elements
R. G. H. Robertson
2013-01-07T23:59:59.000Z
Neutrinoless double beta decay has been the subject of intensive theoretical work as it represents the only practical approach to discovering whether neutrinos are Majorana particles or not, and whether lepton number is a conserved quantum number. Available calculations of matrix elements and phase-space factors are reviewed from the perspective of a future large-scale experimental search for neutrinoless double beta decay. Somewhat unexpectedly, a uniform inverse correlation between phase space and the square of the nuclear matrix element emerges. As a consequence, no isotope is either favored or disfavored; all have qualitatively the same decay rate per unit mass for any given value of the Majorana mass.
Negative mode problem in false vacuum decay with gravity
George Lavrelashvili
2000-04-08T23:59:59.000Z
There is a single negative mode in the spectrum of small perturbations about the tunneling solutions describing a metastable vacuum decay in flat spacetime. This mode is needed for consistent description of decay processes. When gravity is included the situation is more complicated. An approach based on elimination of scalar field perturbations shows no negative mode, whereas the recent approach based on elimination of gravitational perturbations indicates presence of a negative mode. In this contribution we analyse and compare the present approaches to the negative mode problem in false vacuum decay with gravity.
False Vacuum Decay in QCD within an Effective Lagrangian Approach
Todd Fugleberg
2000-06-19T23:59:59.000Z
In an effective Lagrangian approach to QCD we nonperturbatively calculate an analytic approximation to the decay rate of a false vacuum per unit volume, $\\Gamma/V$. We do so for both zero and high temperature theories. This result is important for the study of the early universe at around the time of the QCD phase transition. It is also important in order to determine the possibility of observing this false vacuum decay at the Relativistic Heavy Ion Collider (RHIC). Previously described dramatic signatures of the decay of false vacuum bubbles would occur in our case as well.
Search for CP Violation in D± Meson Decays to ??±
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Stari?, M.; Aihara, H.; Arinstein, K.; Asner, D. M.; Aushev, T.; Bakich, A. M.; Bay, A.; Bhardwaj, V.; Bhuyan, B.; Bozek, A.; Bra?ko, M.; Browder, T. E.; Chen, A.; Chen, P.; Cheon, B. G.; Chilikin, K.; Chistov, R.; Cho, I.-S.; Cho, K.; Choi, Y.; Doležal, Z.; Drásal, Z.; Eidelman, S.; Fast, J. E.; Gaur, V.; Gabyshev, N.; Golob, B.; Haba, J.; Hayasaka, K.; Horii, Y.; Hoshi, Y.; Hou, W.-S.; Hsiung, Y. B.; Iijima, T.; Inami, K.; Ishikawa, A.; Itoh, R.; Iwabuchi, M.; Iwasaki, Y.; Iwashita, T.; Julius, T.; Kang, J. H.; Kawasaki, T.; Kiesling, C.; Kim, H. J.; Kim, H. O.; Kim, J. B.; Kim, K. T.; Kim, M. J.; Kim, Y. J.; Kinoshita, K.; Ko, B. R.; Kobayashi, N.; Koblitz, S.; Kodyš, P.; Korpar, S.; Križan, P.; Kumita, T.; Kwon, Y.-J.; Lange, J. S.; Lee, S.-H.; Li, J.; Li, Y.; Libby, J.; Liu, C.; Liu, Z. Q.; Louvot, R.; McOnie, S.; Miyabayashi, K.; Miyata, H.; Miyazaki, Y.; Mohanty, G. B.; Nakano, E.; Natkaniec, Z.; Nishida, S.; Nitoh, O.; Nozaki, T.; Ohshima, T.; Okuno, S.; Olsen, S. L.; Pakhlova, G.; Park, H. K.; Park, K. S.; Pestotnik, R.; Petri?, M.; Piilonen, L. E.; Röhrken, M.; Ryu, S.; Sahoo, H.; Sakai, K.; Sakai, Y.; Sanuki, T.; Schneider, O.; Schwanda, C.; Schwartz, A. J.; Seon, O.; Sevior, M. E.; Shebalin, V.; Shen, C. P.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Simon, F.; Smerkol, P.; Sohn, Y.-S.; Sokolov, A.; Stani?, S.; Sumihama, M.; Sumisawa, K.; Tatishvili, G.; Teramoto, Y.; Trabelsi, K.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Urquijo, P.; Varner, G.; Vossen, A.; Wang, C. H.; Wang, M.-Z.; Watanabe, M.; Watanabe, Y.; Williams, K. M.; Won, E.; Yabsley, B. D.; Yamashita, Y.; Yuan, C. Z.; Zhang, C. C.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.
2012-02-01T23:59:59.000Z
We search for CP violation in Cabibbo-suppressed charged D meson decays by measuring the difference between the CP-violating asymmetries for the Cabibbo-suppressed decays D±?K?K??± and the Cabibbo-favored decays D±s?K?K??± in the K?K? mass region of the ? resonance. Using 955 fb?¹ of data collected with the Belle detector, we obtain AD?????CP=(+0.51±0.28±0.05)%. The measurement improves the sensitivity of previous searches by more than a factor of 5. We find no evidence for direct CP violation.
Exclusive hadronic B decays to charm and charmonium final states
Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kwak, Nowhan; Lam, H.
1994-07-01T23:59:59.000Z
and hadronic B meson decays. This paper is structured in the following manner. The data sample, detector, and reconstruction procedures are described in Secs. II and III. Branching ratios are given for B ~ Dm and B —+ Dp modes in Sec. IV. In Sec. V results... on branching ratios, polarizations, and 6- nal state substructure for B ~ D*vr, B ~ D'p, and B m D'az are described. Section VI describes a search for D** production in hadronic B decay. This is followed by Sec. VII on exclusive B decays to charmonium, and Sec...
Selected Topics on Hadronic B Decays From BaBar
Suzuki, K.; /SLAC
2011-11-23T23:59:59.000Z
Recent measurements of branching fractions and decay-rate asymmetries in charmless hadronic B decays at the BaBar experiment are presented. The selected topics include Dalitz plot analyses of B {yields} K{sup +} {pi}{sup -}{pi} and signal searches in B {yields} PP and PV, where isoscalar mesons are involved, and in B {yields} b{sub 1}P, P and V denote a pseudoscalar and vector meson, respectively. Several measurements in charmless hadronic B decays have indicated possible deviations from the theoretical predictions within the Standard Model. The measurements presented would contribute to searching for and resolving such puzzles.
Study of Radiative Decays of Psi(2S) Mesons
Kaiyan Gao
2009-09-16T23:59:59.000Z
We studied the decay psi(2S) to gamma eta_c(2S) with 25.9 million psi(2S) events collected with the CLEO-c detector. No psi(2S) to gamma eta_c(2S) decays were observed in any of the eleven exclusive eta_c(2S) decay modes studied. The product branching fraction upper limits were determined for all modes. The 90% confidence level upper limit of branching fraction of psi(2S) to gamma eta_c (2S) was obtained.
Status of the experiments on radiative branch of decay
R. U. Khafizov; S. V. Tolokonnikov; V. A. Solovei; M. R. Kolhidashvili
2009-03-09T23:59:59.000Z
This report is dedicated to the investigation of radiative neutron decay. The theoretical spectrum of radiative gamma quanta, calculated within the framework of the standard electroweak interaction model, is compared with our experimental value of branching ratio (B.R.) for radiative neutron decay. It is noted that the study of radiative branches of elementary particle decay occupies a central place in the fundamental problem of searching for deviations from the standard electroweak model. Particular attention is paid to analyzing the results of the experiment conducted at the FRMII reactor of the Technical University of Munich in 2005.
Decays of Charmed Mesons to PV Final States
Bhubanjyoti Bhattacharya; Jonathan L. Rosner
2008-12-16T23:59:59.000Z
New data on the decays of the charmed particles $D^0$, $D^+$, and $D_s$ to $PV$ final states consisting of a light pseudoscalar meson $P$ and a light vector meson $V$ are analyzed. Following the same methods as in a previous analysis of $D \\to PP$ decays, one can test flavor symmetry, extract key key amplitudes, and obtain information on relative strong phases. Analyses are performed for Cabibbo-favored decays and then extended to predict properties of singly- and doubly-Cabibbo-suppressed processes.
Are the B decay anomalies related to neutrino oscillations?
Boucenna, Sofiane M; Vicente, Avelino
2015-01-01T23:59:59.000Z
Neutrino oscillations are solidly established, with a hint of CP violation just emerging. Similarly, there are hints of lepton universality violation in $b \\to s$ transitions at the level of $2.6 \\sigma$. By assuming that the unitary transformation between weak and mass charged leptons equals the leptonic mixing matrix measured in neutrino oscillation experiments, we predict several lepton flavor violating (LFV) B meson decays. We are led to the tantalizing possibility that some LFV branching ratios for B decays correlate with the leptonic CP phase $\\delta$ characterizing neutrino oscillations. Moreover, we also consider implications for $\\ell_i \\to \\ell_j \\ell_k \\ell_k$ decays.
Suppressing Proton Decay in Theories with Localised Fermions
Bobby S. Acharya; Roberto Valandro
2006-08-01T23:59:59.000Z
We calculate the contribution to the proton decay amplitude from Kaluza-Klein lepto-quarks in theories with extra dimensions, localised fermions and gauge fields which propagate in the bulk. Such models naturally occur within the context of M-theory. In SU(5) models we show that carefully including all such modes gives a distinctive pattern of decays through various channels including a strong suppression of decays into neutrinos or right handed positrons. By contrast there is no such suppression for SO(10).
Improved bounds on SUSY accompanied neutrinoless double beta decay
H. Päs; M. Hirsch; H. V. Klapdor-Kleingrothaus
1999-07-14T23:59:59.000Z
Neutrinoless double beta decay induced by light Majorana neutrino exchange between two decaying nucleons with squark/slepton exchange inside one and W exchange inside the other nucleon (so-called vector-scalar exchange) gives stringent limits on R-parity violating interactions. We have extended previous work by including the tensor contribution to the transition rate. We discuss the improved limits on trilinear \\Rp -MSSM couplings imposed by the current experimental limit on the $\\znbb$ decay half-life of $^{76}$Ge.
Majorons Without Majorana Masses and Neutrinoless Double Beta Decay
C. P. Burgess; J. M. Cline
1992-09-30T23:59:59.000Z
We explain excess events near the endpoints of the double beta decay spectra of several elements, using the neutrinoless emission of massless Goldstone bosons. Models with scalars carrying lepton number $-2$ are proposed for this purpose so that ordinary neutrinoless double beta decay is forbidden, and we can raise the scale of global symmetry breaking above the 10 keV scale needed for observable emission of conventional Majorons in double beta decay. The electron spectrum has a different shape, and the rate depends on different nuclear matrix elements, than for the emission of ordinary Majorons.
Neutrinoless Double Beta Decay and Physics Beyond the Standard Model
Rabindra N. Mohapatra
1995-07-05T23:59:59.000Z
The various mechanisms for neutrinoless double beta decay in gauge theories are reviewed and the present experimental data is used to set limits on physics scenarios beyond the standard model. The positive indications for nonzero neutrino masses in various experiments such as those involving solar, atmospheric and accelerator neutrinos are discussed and it is pointed out how some neutrino mass textures consistent with all data can be tested by the ongoing double beta decay experiments. Finally, the outlook for observable neutrinoless double beta decay signal in grand unified theories is discussed.
Searches for New Physics in Top Decays at D0
Pleier, Marc-Andre; /Brookhaven
2011-08-01T23:59:59.000Z
The Tevatron proton-antiproton collider at Fermilab with its centre of mass energy of 1.96 TeV allows for pair production of top quarks and the study of top quark decay properties. This report reflects the current status of measurements of the W boson helicity in top quark decays and the ratio of top quark branching fractions as well as searches for neutral current top quark decays and pair production of fourth generation t' quarks, performed by the D0 Collaboration utilising datasets of up to 5.4 fb{sup -1}.
Recent BaBar Results on $B$ Decays
Clark, P.J.; /Edinburgh U.
2011-11-15T23:59:59.000Z
Several recent key results from the BABAR experiment are presented, most using 383.6 fb{sup -1} of data. In particular, the search for B{sup +} {yields} {tau}{sup +}{nu}, inclusive and exclusive measurements of |V{sub ub}|, measurements of b {yields} d{gamma} decays and new observations of rare charmless hadronic decays. The new results provide important experimental constraints on the Standard Model and new physics models. Keywords: B decays; flavor; leptonic; semi-leptonic, radiative, hadronic.
Pionic contribution to neutrinoless double beta decay
Vergados, J. D. [Physics Department, University of Ioannina, Ioannina, GR 451 10 (Greece); Theory Division, CERN, Geneva (Switzerland); Faessler, Amand [Institute fuer Theoretische Physik, Universitaet Tuebingen (Germany); Toki, H. [RCNP, Osaka University, Osaka, 567-0047 (Japan)
2010-02-01T23:59:59.000Z
It is well known that neutrinoless double decay is going to play a crucial role in settling the neutrino properties, which cannot be extracted from the neutrino oscillation data. It is, in particular, expected to settle the absolute scale of neutrino mass and determine whether the neutrinos are Majorana particles, i.e. they coincide with their own antiparticles. In order to extract the average neutrino mass from the data, one must be able to estimate the contribution of all possible high mass intermediate particles. The latter, which occur in practically all extensions of the standard model, can, in principle, be differentiated from the usual mass term, if data from various targets are available. One, however, must first be able to reliably calculate the corresponding nuclear matrix elements. Such calculations are extremely difficult since the effective transition operators are very short ranged. For such operators processes like pionic contributions, which are usually negligible, turn out to be dominant. We study such an effect in a nonrelativistic quark model for the pion and the nucleon.
A Dispersive Treatment of $K_{\\ell4}$ Decays
Colangelo, Gilberto; Stoffer, Peter
2015-01-01T23:59:59.000Z
$K_{\\ell4}$ decays offer several reasons of interest: they allow an accurate measurement of $\\pi\\pi$-scattering lengths; they provide the best source for the determination of some low-energy constants of ChPT; one form factor is directly related to the chiral anomaly, which can be measured here. We present a dispersive treatment of $K_{\\ell4}$ decays that provides a resummation of $\\pi\\pi$- and $K\\pi$-rescattering effects. The free parameters of the dispersion relation are fitted to the data of the high-statistics experiments E865 and NA48/2. The matching to ChPT at NLO and NNLO enables us to determine the LECs $L_1^r$, $L_2^r$ and $L_3^r$. With recently published data from NA48/2, the LEC $L_9^r$ can be determined as well. In contrast to a pure chiral treatment, the dispersion relation describes the observed curvature of one of the form factors, which we understand as a rescattering effect beyond NNLO.
A Dispersive Treatment of $K_{\\ell4}$ Decays
Gilberto Colangelo; Emilie Passemar; Peter Stoffer
2015-01-22T23:59:59.000Z
$K_{\\ell4}$ decays offer several reasons of interest: they allow an accurate measurement of $\\pi\\pi$-scattering lengths; they provide the best source for the determination of some low-energy constants of ChPT; one form factor is directly related to the chiral anomaly, which can be measured here. We present a dispersive treatment of $K_{\\ell4}$ decays that provides a resummation of $\\pi\\pi$- and $K\\pi$-rescattering effects. The free parameters of the dispersion relation are fitted to the data of the high-statistics experiments E865 and NA48/2. The matching to ChPT at NLO and NNLO enables us to determine the LECs $L_1^r$, $L_2^r$ and $L_3^r$. With recently published data from NA48/2, the LEC $L_9^r$ can be determined as well. In contrast to a pure chiral treatment, the dispersion relation describes the observed curvature of one of the form factors, which we understand as a rescattering effect beyond NNLO.
Search for CP violation in charged D meson decays
Yumiceva, Francisco Xavier; /South Carolina U.
2005-05-04T23:59:59.000Z
At the present time, Charge-Parity asymmetry or CP Violation is one of the most studied topics in high energy physics. Precise measurements of CP parameters can test sensitive sectors of the Standard Model (SM). These measurements could also give us clues about physics beyond the SM. Furthermore, since CP Violation is one of the necessary conditions for generating a matter-antimatter asymmetric Universe according to the baryogenesis model of Sakharov, a better understanding of these processes will improve our knowledge about the origin of the Universe. CP Violation in single Cabibbo-Suppressed charged D meson decays is predicted by the SM to have asymmetries of the order of {Omicron}(10{sup -3}), results bigger than this will be strong evidence of physics beyond the SM. We report results of the search for CP violation in D{sup +} {yields} K{sup -}K{sup +}{pi}{sup +} meson decays. The selection criteria were optimized using a control sample from data with a luminosity of 9.8 fb{sup -1}.
False Vacuum Transitions - Analytical Solutions and Decay Rate Values
Correa, R A C; da Rocha, Roldao
2015-01-01T23:59:59.000Z
In this work we show a class of oscillating configurations for the evolution of the domain walls in Euclidean space. The solutions are obtained analytically. We also find the decay rate of the false vacuum.
Fate of the false monopoles: Induced vacuum decay
Kumar, Brijesh [Physics Department, Indian Institute of Technology Bombay, Mumbai, 400076 (India); Groupe de physique des particules, Departement de physique, Universite de Montreal, Case Postale 6128, succursale Centre-ville, Montreal, Quebec, H3C 3J7 (Canada); Paranjape, M. B. [Groupe de physique des particules, Departement de physique, Universite de Montreal, Case Postale 6128, succursale Centre-ville, Montreal, Quebec, H3C 3J7 (Canada); Yajnik, U. A. [Physics Department, Indian Institute of Technology Bombay, Mumbai, 400076 (India); Groupe de physique des particules, Departement de physique, Universite de Montreal, Case Postale 6128, succursale Centre-ville, Montreal, Quebec, H3C 3J7 (Canada); Department of Physics, Ernest Rutherford Physics Building, McGill University, 3600 rue University, Montreal, Quebec, H3A 2T5 (Canada)
2010-07-15T23:59:59.000Z
We study a gauge theory model where there is an intermediate symmetry breaking to a metastable vacuum that breaks a simple gauge group to a U(1) factor. Such a model admits the existence of metastable magnetic monopoles, which we dub false monopoles. We prove the existence of these monopoles in the thin-wall approximation. We determine the instantons for the collective coordinate that corresponds to the radius of the monopole wall and we calculate the semiclassical tunneling rate for the decay of these monopoles. The monopole decay consequently triggers the decay of the false vacuum. As the monopole mass is increased, we find an enhanced rate of decay of the false vacuum relative to the celebrated homogeneous tunneling rate due to S. R. Coleman [Subnuclear series 13, 297 (1977).].
False Vacuum Transitions - Analytical Solutions and Decay Rate Values
R. A. C. Correa; P. H. R. S. Moraes; Roldao da Rocha
2015-04-28T23:59:59.000Z
In this work we show a class of oscillating configurations for the evolution of the domain walls in Euclidean space. The solutions are obtained analytically. We also find the decay rate of the false vacuum.
Fate of the false monopoles: induced vacuum decay
Brijesh Kumar; M. B. Paranjape; U. A. Yajnik
2010-06-03T23:59:59.000Z
We study a gauge theory model where there is an intermediate symmetry breaking to a meta- stable vacuum that breaks a simple gauge group to a U (1) factor. Such models admit the existence of meta-stable magnetic monopoles, which we dub false monopoles. We prove the existence of these monopoles in the thin wall approximation. We determine the instantons for the collective coordinate that corresponds to the radius of the monopole wall and we calculate the semi-classical tunneling rate for the decay of these monopoles. The monopole decay consequently triggers the decay of the false vacuum. As the monopole mass is increased, we find an enhanced rate of decay of the false vacuum relative to the celebrated homogeneous tunneling rate due to Coleman [1].
Scalar-tensor gravitational effects on vacuum decay
Accetta, F.S.; Romanelli, P. (Center for Theoretical Physics, Department of Physics, Yale University, New Haven, Connecticut 06511 (USA))
1990-05-15T23:59:59.000Z
Motivated by a recently proposed extended'' inflation scenario, we apply the formalism of Coleman and De Luccia to the false-vacuum decay of a scalar field coupled to a scalar-tensor theory of gravity. In particular, we discuss a model for false-vacuum decay of a scalar field {sigma} minimally coupled in a Brans-Dicke-like theory of gravity. In such theories, the effective gravitational constant is a function of a scalar field {phi}. In general, {phi} will have nontrivial dynamics in the false vacuum, and as {phi} varies the decay rate of the {sigma} false vacuum need not be constant. We present both an explicit thin-wall'' calculation of the decay rate, and a more general numerical thick-wall'' calculation, comparing them to the standard results for Einstein gravity. We consider some questions of principle concerning boundary conditions for the {phi} field. We discuss the consequences of these results for extended models of inflation.
Renewal convergence rates and correlation decay for homogeneous pinning models
Giambattista Giacomin
2007-06-03T23:59:59.000Z
A class of discrete renewal processes with super-exponentially decaying inter-arrival distributions coincides with the infinite volume limit of general homogeneous pinning models in their localized phase. Pinning models are statistical mechanics systems to which a lot of attention has been devoted both for their relevance for applications and because they are solvable models exhibiting a non-trivial phase transition. The spatial decay of correlations in these systems is directly mapped to the speed of convergence to equilibrium for the associated renewal processes. We show that close to criticality, under general assumptions, the correlation decay rate, or the renewal convergence rate, coincides with the inter-arrival decay rate. We also show that, in general, this is false away from criticality. Under a stronger assumption on the inter-arrival distribution we establish a local limit theorem, capturing thus the sharp asymptotic behavior of correlations.
Observation of the Decay B??Ds(*)+K?l????l
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D. N.; Hooberman, B.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Osipenkov, I. L.; Tanabe, T.; Hawkes, C. M.; Watson, A. T.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Randle-Conde, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Curry, S.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Martin, E. C.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; Eisner, A. M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Winstrom, L. O.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Dubrovin, M. S.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Jasper, H.; Karbach, T. M.; Merkel, J.; Petzold, A.; Spaan, B.; Wacker, K.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Watson, J. E.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cecchi, A.; Cibinetto, G.; Fioravanti, E.; Franchini, P.; Luppi, E.; Munerato, M.; Negrini, M.; Petrella, A.; Piemontese, L.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Nicolaci, M.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Tosi, S.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Adametz, A.; Marks, J.; Schenk, S.; Uwer, U.; Bernlochner, F. U.; Ebert, M.; Lacker, H. M.; Lueck, T.; Volk, A.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Crawley, H. B.; Dong, L.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gao, Y. Y.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Derkach, D.; Firmino da Costa, J.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Perez, A.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Wang, L.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Paramesvaran, S.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; West, T. J.; Anderson, J.; Cenci, R.; Jawahery, A.; Roberts, D. A.; Simi, G.; Tuggle, J. M.; Dallapiccola, C.; Salvati, E.; Cowan, R.; Dujmic, D.; Fisher, P. H.; Sciolla, G.; Zhao, M.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Simard, M.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Corwin, L. A.; Honscheid, K.; Kass, R.; Morris, J. P.; Rahimi, A. M.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Kolb, J. A.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Castelli, G.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Ben-Haim, E.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Prendki, J.; Sitt, S.; Biasini, M.; Manoni, E.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Neri, N.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Baracchini, E.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Renga, F.; Hartmann, T.; Leddig, T.; Schröder, H.; Waldi, R.; Adye, T.; Franek, B.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Zito, M.; Allen, M. T.; Aston, D.; Bard, D. J.; Bartoldus, R.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.
2011-07-01T23:59:59.000Z
We report the observation of the decay B??Ds(*)+K?l??¯l based on 342fb?¹ of data collected at the ?(4S) resonance with the BABAR detector at the PEP-II e?e? storage rings at SLAC. A simultaneous fit to three D+s decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay B??Ds(*)+K?l??¯l with a significance greater than 5 standard deviations (including systematic uncertainties) and measure its branching fraction to be B(B??Ds(*)+K?l??¯l)=[6.13+1.04-1.03(stat)±0.43(syst)±0.51(B(Ds))]×10??, where the last error reflects the limited knowledge of the Ds branching fractions.
Upper limit on branching ratio the decay B. Bassalleck,
National Laboratory (BNL). The decay forbidden angular momentum conservation neutrinos purely massless left## # cosmological constraints neutrino masses imply more stringent limits. branching 0 ## case massive Majorana Brookhaven National Laboratory, Upton, New 11973, USA TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia
Sterile neutrino search with kaon decay at rest
Spitz, Joshua B.
Monoenergetic muon neutrinos (235.5 MeV) from positive kaon decay at rest are considered as a source for an electron neutrino appearance search. In combination with a liquid argon time projection chamber based detector, ...
Searching for Double Beta Decay with the Enriched Xenon Observatory
Hall, C.; /SLAC
2007-03-16T23:59:59.000Z
The Enriched Xenon Observatory (EXO) Collaboration is building a series of experiments to search for the neutrinoless double beta decay of {sup 136}Xe. The first experiment, known as EXO-200, will utilize 200 kg of xenon enriched to 80% in the isotope of interest, making it the largest double beta decay experiment to date by one order of magnitude. This experiment is rapidly being constructed, and will begin data taking in 2007. The EXO collaboration is also developing a technique to identify on an event-by-event basis the daughter barium ion of the double beta decay. If successful, this method would eliminate all conventional radioactive backgrounds to the decay, resulting in an ideal experiment. We summarize here the current status of EXO-200 construction and the barium tag R&D program.
?-decay spectroscopy for the r-process nucleosynthesis
Nishimura, Shunji [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Collaboration: RIBF Decay Collaborations
2014-05-09T23:59:59.000Z
Series of decay spectroscopy experiments, utilizing of high-purity Ge detectors and double-sided silicon-strip detectors, have been conducted to harvest the decay properties of very exotic nuclei relevant to the r-process nucleosynthesis at the RIBF. The decay properties such as ?-decay half-lives, low-lying states, ?-delayed neutron emissions, isomeric states, and possibly Q{sub ?} of the very neutron-rich nuclei are to be measured to give significant constraints in the uncertainties of nuclear properties for the r-process nucleosynthesis. Recent results of ?? spectroscopy study using in-flight fission of {sup 238}U-beam will be presented together with our future perspectives.
Beta decay rates for nuclei with 115 nucleosynthesis
Kamales Kar; Soumya Chakravarti; V. R. Manfredi
2006-03-19T23:59:59.000Z
For r-process nucleosynthesis the beta decay rates for a number of neutron-rich intermediate heavy nuclei are calculated. The model for the beta strength function is able to reproduce the observed half~lives quite well.
Observations of Electrons from the Decay of Solar Flare Neutrons
W. Dröge; D. Ruffolo; B. Klecker
1996-04-03T23:59:59.000Z
We have found evidence for fluxes of energetic electrons in interplanetary space on board the ISEE-3 spacecraft which we interpret as the decay products of neutrons generated in a solar flare on 1980 June 21. The decay electrons arrived at the s/c shortly before the electrons from the flare and can be distinguished from the latter by their distinctive energy spectrum. The time profile of the decay electrons is in good agreement with the results from a simulation based on a scattering mean free path derived from a fit to the flare electron data. The comparison with simultaneously observed decay protons and a published direct measurement of high-energy neutrons places important constraints on the parent neutron spectrum.
Comment on "Evidence for Neutrinoless Double Beta Decay"
C. E. Aalseth; F. T. Avignone III; A. Barabash; F. Boehm; R. L. Brodzinski; J. I. Collar; P. J. Doe; H. Ejiri; S. R. Elliott; E. Fiorini; R. J. Gaitskell; G. Gratta; R. Hazama; K. Kazkaz; G. S. King III; R. T. Kouzes; H. S. Miley; M. K. Moe; A. Morales; J. Morales; A. Piepke; R. G. H. Robertson; W. Tornow; P. Vogel; R. A. Warner; J. F. Wilkerson
2002-05-22T23:59:59.000Z
We comment on the recent claim for the experimental observation of neutrinoless double-beta decay. We discuss several limitations in the analysis provided in that paper and conclude that there is no basis for the presented claim.
Neutrinoless double beta decay, solar neutrinos and mass scales
Per Osland; Geir Vigdel
2001-09-13T23:59:59.000Z
We obtain bounds for the neutrino masses by combining atmospheric and solar neutrino data with the phenomenology of neutrinoless double beta decay where hypothetical values of || are envisaged from future 0\
Bounds on Compositeness from Neutrinoless Double Beta Decay
Orlando Panella; Yogendra N. Srivastava
1994-11-07T23:59:59.000Z
Assuming the existence of a heavy Majorana neutral particle arising from a composite model scenario we discuss the constraints imposed by present experimental limits of half-life neutrinoless double beta decay $(0\
Non-decaying hydrodynamic interactions along narrow channels
Misiunas, Karolis; Lauga, Eric; Lister, John R; Keyser, Ulrich F
2015-01-01T23:59:59.000Z
Particle-particle interactions are of paramount importance in every multi-body system as they determine the collective behaviour and coupling strength. Many well-known interactions like electro-static, van der Waals or screened Coulomb, decay exponentially or with negative powers of the particle spacing r. Similarly, hydrodynamic interactions between particles undergoing Brownian motion decay as 1/r in bulk, and are assumed to decay quickly in small channels. Such interactions are ubiquitous in biological and technological systems. Here we confine two particles undergoing Brownian motion in narrow, microfluidic channels and study their coupling through hydrodynamic interactions. Our experiments show that, in contrast to expectations from current theoretical understanding, the hydrodynamic particle-particle interactions are long-range and non-decaying in these channels. This new effect is of fundamental importance for the interpretation of experiments where dense mixtures of particles or molecules diffuse thro...
Ultra High Energy Cosmic Rays from Decaying Superheavy Particles
V. Berezinsky
1998-01-08T23:59:59.000Z
Decaying superheavy particles can be produced by Topological Defects or, in case they are quasi-stable, as relics from the early Universe. The decays of these particles can be the sources of observed Ultra High Energy Cosmic Rays ($E \\sim 10^{10} - 10^{12} GeV$). The Topological Defects as the UHE CR sources are critically reviewed and cosmic necklaces and monopole-antiminopole pairs are identified as most plausible sources. The relic superheavy particles are shown to be clustering in the halo and their decays produce UHE CR without GZK cutoff. The Lightest Supersymmetric Particles with Ultra High Energies are naturally produced in the cascades accompanying the decays of superheavy particles. These particles are discussed as UHE carriers in the Universe.
Hierarchy of scales in B{yields}PS decays
Delepine, D.; Lucio M, J. L. [Instituto de Fisica, Universidad de Guanajuato Loma del Bosque no 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Mendoza S, J. A. [Depto. de Fisica-Matematicas, Universidad de Pamplona Pamplona, Norte de Santander (Colombia); Ramirez, Carlos A. [Escuela de Fisica, Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia)
2008-08-31T23:59:59.000Z
We show that the naive factorization approach can accommodate the existence of the observed hierarchy of branching ratios for the B{yields}PS decays (P stands for pseudoscalar and S for scalar mesons respectively.
Search for rare charm meson decays at FNAL E791
D. J. Summers
2003-08-14T23:59:59.000Z
We report the results of a blind search for flavor-changing neutral current (FCNC), lepton-flavor violating, and lepton-number violating decays of D{sup +}, D{sub s}{sup +}, and D{sup 0} mesons (and their antiparticles) into 2-, 3-, and 4-body states including a lepton pair. Such decays may involve Flavor-Changing Neutral Currents, Leptoquarks, Horizontal Gauge Bosons, or Majorana Neutrinos. No evidence for any of these decays is found. Therefore, we present 90% confidence level branching-fraction upper limits, typically at the 10{sup -4} level. A total of 51 decay channels have been examined; 26 have not been previously reported and 18 are significant improvements over previous results.
A Direct Measurement of the $W$ Decay Width
Vine, Troy; /University Coll. London
2008-08-01T23:59:59.000Z
A direct measurement of the W boson total decay width is presented in proton-antiproton collisions at {radical}s = 1.96 TeV using data collected by the CDF II detector. The measurement is made by fitting a simulated signal to the tail of the transverse mass distribution in the electron and muon decay channels. An integrated luminosity of 350 pb{sup -1} is used, collected between February 2002 and August 2004. Combining the results from the separate decay channels gives the decay width as 2.038 {+-} 0.072 GeV in agreement with the theoretical prediction of 2.093 {+-} 0.002 GeV. A system is presented for the management of detector calibrations using a relational database schema. A description of the implementation and monitoring of a procedure to provide general users with a simple interface to the complete set of calibrations is also given.
Nuclear Structure Aspects of Neutrinoless Double Beta Decay
B. A. Brown; M. Horoi; R. A. Sen'kov
2014-09-25T23:59:59.000Z
We decompose the neutrinoless double-beta decay matrix elements into sums of products over the intermediate nucleus with two less nucleons. We find that the sum is dominated by the J^pi=0^+ ground state of this intermediate nucleus for both the light and heavy neutrino decay processes. This provides a new theoretical tool for comparing and improving nuclear structure models. It also provides the connection to two-nucleon transfer experiments.
Effect of nuclear deformation on double beta decay
Rodin, Vadim [Institute fuer Theoretische Physik der Universitaet Tuebingen, D-72076 Tuebingen (Germany)
2009-11-09T23:59:59.000Z
The existing ways of accounting for deformation in recent calculations of neutrinoless double beta decay matrix elements are discussed. From an analysis of relevant experimental data it is argued that only {sup 150}Nd reveals convincing evidences of strong static deformation, which should eventually be taken into account in QRPA calculations. A proposal which allows in principle to measure the neutrino less double beta decay Fermi matrix element is briefly described.
Nuclear Structure Aspects of Neutrinoless Double Beta Decay
Brown, B A; Sen'kov, R A
2014-01-01T23:59:59.000Z
We decompose the neutrinoless double-beta decay matrix elements into sums of products over the intermediate nucleus with two less nucleons. We find that the sum is dominated by the J^pi=0^+ ground state of this intermediate nucleus for both the light and heavy neutrino decay processes. This provides a new theoretical tool for comparing and improving nuclear structure models. It also provides the connection to two-nucleon transfer experiments.
False vacuum decay with gravity in a critical case
Michal Demetrian
2005-05-17T23:59:59.000Z
The vacuum decay in a de Sitter universe is studied within semiclassical approximation for the class of effective inflaton potentials whose curvature at the top is close to a critical value. By comparing the actions of the Hawking - Moss instanton and the Coleman - de Luccia instanton(s) the mode of vacuum decay is determined. The case when the fourth derivative of the effective potential at its top is less than a critical value is discussed.
Super-Kamiokande data and atmospheric neutrino decay
G. L. Fogli; E. Lisi; A. Marrone; G. Scioscia
1999-02-08T23:59:59.000Z
Neutrino decay has been proposed as a possible solution to the atmospheric neutrino anomaly, in the light of the recent data from the Super-Kamiokande experiment. We investigate this hypothesis by means of a quantitative analysis of the zenith angle distributions of neutrino events in Super-Kamiokande, including the latest (45 kTy) data. We find that the neutrino decay hypothesis fails to reproduce the observed distributions of muons.
Neutrinoless Double Beta Decay with Negligible Neutrino Mass
Biswajoy Brahmachari; Ernest Ma
2002-02-27T23:59:59.000Z
If the electron neutrino has an effective nonzero Majorana mass, then neutrinoless double beta decay will occur. However, the latter is possible also with a negligible neutrino mass. We show how this may happen in a simple model of scalar diquarks and dileptons. This possibility allows neutrino masses to be small and hierarchical, without conflicting with the possible experimental evidence of neutrinoless double beta decay.
Searching for the fourth family quarks through anomalous decays
Sahin, M.; Sultansoy, S.; Turkoz, S. [TOBB University of Economics and Technology, Physics Division, Ankara (Turkey); TOBB University of Economics and Technology, Physics Division, Ankara, Turkey and Institute of Physics, National Academy of Sciences, Baku (Azerbaijan); Ankara University, Department of Physics, Ankara (Turkey)
2010-09-01T23:59:59.000Z
The flavor democracy hypothesis predicts the existence of the fourth standard model family. Because of the high masses of the fourth family quarks, their anomalous decays could be dominant if certain criteria are met. This will drastically change the search strategy at hadron colliders. We show that the fourth standard model family down quarks with masses up to 400-450 GeV can be observed (or excluded) via anomalous decays by Tevatron.
Particle decay in Ising field theory with magnetic field
Gesualdo Delfino
2007-03-30T23:59:59.000Z
The scaling limit of the two-dimensional Ising model in the plane of temperature and magnetic field defines a field theory which provides the simplest illustration of non-trivial phenomena such as spontaneous symmetry breaking and confinement. Here we discuss how Ising field theory also gives the simplest model for particle decay. The decay widths computed in this theory provide the obvious test ground for the numerical methods designed to study unstable particles in quantum field theories discretized on a lattice.
The determination of permeability using a pulse decay technique
Rowe, William Charlton
1985-01-01T23:59:59.000Z
THE DETERMINATION OF PERMEABILITY USING A PULSE DECAY TECHNIQUE A Thesis by WILLIAM CHARLTON ROWE Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 1985 Major Subject: Petroleum Engineering THE DETERMINATION OF PERMEABILITY USING A PULSE DECAY TECHNIQUE A Thesis by WILLIAM CHARLTON ROME Approved as to style and content by: S. A. Holditch (Chairman of Committee) R. R. Berg (Memb r...
Examination of radioactive decay methodology in the HASCAL code
Steffler, R.S. [Texas A and M Univ., College Station, TX (United States). Dept. of Nuclear Engineering; Ryman, J.C.; Gehin, J.C.; Worley, B.A. [Oak Ridge National Lab., TN (United States)
1998-01-01T23:59:59.000Z
The HASCAL 2.0 code provides dose estimates for nuclear, chemical, and biological facility accident and terrorist weapon strike scenarios. In the analysis of accidents involving radioactive material, an approximate method is used to account for decay during transport. Rather than perform the nuclide decay during the atmospheric transport calculation, the decay is performed a priori and a table look up method is used during the transport of a depositing tracer particle and non depositing (gaseous) tracer particle. In order to investigate the accuracy of this decay methodology two decay models were created using the ORIGEN2 computer program. The first is a HASCAL like model that treats decay and growth of all nuclide explicitly over the time interval specified for atmospheric transport, but does not change the relative mix of depositing and non-depositing nuclides due to deposition to the ground, nor does it treat resuspension. The second model explicitly includes resuspension as well as separate decay of the nuclides in the atmosphere and on the ground at each deposition time step. For simplicity, both of these models uses a one-dimensional layer model for the atmospheric transport. An additional investigation was performed to determine the accuracy of the HASCAL like model in separately following Cs-137 and I-131. The results from this study show that the HASCAL decay model compares closely with the more rigorous model with the computed doses are generally within one percent (maximum error of 7 percent) over 48 hours following the release. The models showed no difference for Cs-137 and a maximum error of 2.5 percent for I-131 over the 96 hours following release.
Cluster-model calculations of exotic decays from heavy nuclei
Buck, B.; Merchant, A.C.
1989-05-01T23:59:59.000Z
A cluster model employing a local, effective cluster-core potential is used to investigate exotic decay from heavy nuclei as a quantum tunneling phenomenon within a semiclassical approximation. Excellent agreement with all reported experimental measurements of the decay widths for /sup 14/C and /sup 24/Ne emission is obtained. As an added bonus, the width for alpha particle emission from /sup 212/Po is also calculated in good agreement with experiment.
Constraints on neutrinoless double beta decay from neutrino oscillation experiments
S. M. Bilenky; C. Giunti; M. Monteno
1997-01-15T23:59:59.000Z
We show that, in the framework of a general model with mixing of three Majorana neutrinos and a neutrino mass hierarchy, the results of the Bugey and Krasnoyarsk reactor neutrino oscillation experiments imply strong limitations for the effective Majorana mass || that characterizes the amplitude of neutrinoless double beta decay. We obtain further limitations on || from the data of the atmospheric neutrino experiments. We discuss the possible implications of the results of the future long baseline neutrino oscillation experiments for neutrinoless double beta decay.
Neutrinoless double beta decay and direct searches for neutrino mass
Craig Aalseth; Henning Back; Loretta Dauwe; David Dean; Guido Drexlin; Yuri Efremenko; Hiro Ejiri; Steven Elliott; Jon Engel; Brian Fujikawa; Reyco Henning; G. W. Hoffmann; Karol Lang; Kevin Lesko; Tadafumi Kishimoto; Harry Miley; Rick Norman; Silvia Pascoli; Serguey Petcov; Andreas Piepke; Werner Rodejohann; David Saltzberg; Sean Sutton; Petr Vogel; Ray Warner; John Wilkerson; Lincoln Wolfenstein
2004-12-21T23:59:59.000Z
Study of the neutrinoless double beta decay and searches for the manifestation of the neutrino mass in ordinary beta decay are the main sources of information about the absolute neutrino mass scale, and the only practical source of information about the charge conjugation properties of the neutrinos. Thus, these studies have a unique role in the plans for better understanding of the whole fast expanding field of neutrino physics.
CP Violation in Neutrinoless Double Beta Decay and Neutrino Oscillation
T. Fukuyama; K. Matsuda; H. Nishiura
1998-03-03T23:59:59.000Z
Taking account of possible CP violation, we discuss about the constraints on the lepton mixing angles from the neutrinoless double beta decay and from the neutrino oscillation for the three flavour Majorana neutrinos. From the CHORUS oscillation experiment, combined with the data of neutrinoless double beta decay, we show that the large angle solution of (\\theta_{23}) is improbable if the neutrino mass (m_3) of the third generation is a candidate of hot dark matters.
Observable Majoron Emission in Neutrinoless Double Beta Decay
Z Berezhiani; A Yu Smirnov; J W F Valle
1992-07-03T23:59:59.000Z
We consider a class of simplest Majoron models where neutrino- majoron couplings can be in the range $g \\sim 10^{-5}-10^{-3}$ leading to the observability of neutrinoless double beta decay with majoron emission. The majoron is a singlet of the electroweak gauge symmetry, thus avoiding conflict with the LEP data on Z decay, which rules out the triplet and doublet majoron models.
Possible stimulation of nuclear alpha-decay by superfluid helium
A. L. Barabanov
2009-09-03T23:59:59.000Z
It is suggested that superfluid helium (condensate of 4-He atoms) may stimulate nuclear alpha-decay in a situation when an alpha-emitter moves through superfluid helium with fine-tuned velocity, so that the backward-emitted alpha-particle is at rest in the laboratory frame. It is shown that the probability of stimulated alpha-decay in this case may be sizable enough to be detected.
Bahcall, John
What can we learn from neutrinoless double beta decay experiments? John N. Bahcall,* Hitoshi-generation neutrinoless double beta decay and normal neutrino beta decay experi- ments can answer four fundamental questions. 1 If neutrinoless double beta decay searches do not detect a signal, and if the spectrum is known
Searches for Exotic Higgs Boson Decays with the ATLAS and the CMS Experiment
Lagouri, Theodota; The ATLAS collaboration
2015-01-01T23:59:59.000Z
This talk will summarize the searches for exotic Higgs boson decays. It should cover decays of the observed Higgs boson to dark sector bosons, lepton flavor violating and flavor changing decays, and decays to a light pseudoscalar neutral Higgs boson as predicted by the NMSSM. Prospects for the LHC run-2 should be given. The talk should cover the results from ATLAS and CMS.
Search for Neutrinoless Double-Beta Decay with CUORE Yury G. Kolomensky, for the CUORE Collaboration
of this ambitious program...". The Long Range Plan further states: "... neutrinoless double beta decay experiments
Syst. Biol. 50(2):215242, 2001 Analysis of Character Correlations Among Wood Decay Mechanisms,
Hibbett, David S.
Syst. Biol. 50(2):215242, 2001 Analysis of Character Correlations Among Wood Decay Mechanisms of wood-decaying fungi. Two basic forms of wood decay are known in homobasidiomycetes: white rot, in which analyses; wood decay.] The vast majority of terrestrial biomass takes the form of wood and other plant tis
TOWARDS A PRECISION MEASUREMENT OF THE HALF LIFE OF NEUTRINOLESS DOUBLE BETA DECAY OF 136
Gratta, Giorgio
). Even if debatable, a first hint came from the claimed observation of neutrinoless double beta decay
Next Generation Neutrinoless Double -Decay Experiments Andreas Piepke, R.G. Hamish Robertson
of this ambitious program...". The Long Range Plan further states: "... neutrinoless double beta decay experiments
A Non-SUSY Model for Neutrino Oscillation, Baryogenesis and Neutrinoless Double Beta Decay
Holger Bech Nielsen; Yasutaka Takanishi
2001-10-09T23:59:59.000Z
We fitted the neutrino oscillations, baryogenesis and neutrinoless double beta decay using Anti-GUT model.
Study of the D0 ---> pi- pi+ pi- pi+ decay
Link, J.M.; Yager, P.M.; /UC, Davis; Anjos, J.C.; Bediaga, I.; Castromonte, C.; Machado, A.A.; Magnin, J.; Massafferri, A.; de Miranda, J.M.; Pepe, I.M.; Polycarpo, E.; /Rio de Janeiro, CBPF /CINVESTAV, IPN /Colorado U. /Fermilab /Frascati /Guanajuato U. /Illinois U., Urbana /Indiana U. /Korea U. /Kyungpook Natl. U. /INFN, Milan /Milan U.
2007-01-01T23:59:59.000Z
Using data from the FOCUS (E831) experiment at Fermilab, they present new measurements for the Cabbibo-suppressed decay mode D{sup 0} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +}. They measure the branching ratio {Lambda}(D{sup 0} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -})/{Lambda}(D{sup 0} {yields} K{sup -} {pi}{sup +}{pi}{sup -}{pi}{sup +}) = 0.0914 {+-} 0.0018 {+-} 0.0022. An amplitude analysis has been performed, a first for this channel, in order to determine the resonant substructure of this decay mode. The dominant component is the decay D{sup 0} {yields} a{sub 1}(1260){sup +}{pi}{sup -}, accounting for 60% of the decay rate. The second most dominant contribution comes from the decay D{sup 0} {yields} {rho}(770){sup 0}{rho}(770){sup 0}, with a fraction of 25%. They also study the a{sub 1}(1260) line shape and resonant substructure. Using the helicity formalism for the angular distribution of the decay D{sup 0} {yields} {rho}(770){sup 0}{rho}(770){sup 0}, they measure a longitudinal polarization of P{sub L} = (71 {+-} 4 {+-} 2)%.
Physics and Outlook for Rare, All-neutral Eta Decays
Mack, David J. [JLAB
2014-06-01T23:59:59.000Z
The $\\eta$ meson provides a laboratory to study isospin violation and search for new flavor-conserving sources of C and CP violation with a sensitivity approaching $10^{-6}$ of the isospin-conserving strong amplitude. Some of the most interesting rare $\\eta$ decays are the neutral modes, yet the effective loss of photons from the relatively common decay $\\eta \\rightarrow 3\\pi^0 \\rightarrow 6\\gamma$ (33$\\%$) has largely limited the sensitivity for decays producing 3-5$\\gamma$'s. Particularly important relevant branches include the highly suppressed $\\eta \\rightarrow \\pi^0 2\\gamma \\rightarrow 4\\gamma$, which provides a rare window on testing models of $O(p^6)$ contributions in ChPTh, and $\\eta \\rightarrow 3\\gamma$ and $\\eta \\rightarrow 2\\pi^0 \\gamma \\rightarrow 5\\gamma$ which provide direct constraints on C violation in flavor-conserving processes. The substitution of lead tungstate in the forward calorimeter of the GluEx setup in Jefferson Lab's new Hall D would allow dramatically improved measurements. The main niche of this facility, which we call the JLab Eta Factory (JEF), would be $\\eta$ decay neutral modes. However, this could likely be expanded to rare $\\eta'(958)$ decays for low energy QCD studies as well as $\\eta$ decays involving muons for new physics searches.
$?$-decay of key titanium isotopes in stellar environment
Jameel-Un Nabi; Irgaziev Bakhadir
2011-08-04T23:59:59.000Z
Amongst iron regime nuclei, $\\beta$-decay rates on titanium isotopes are considered to be important during the late phases of evolution of massive stars. The key $\\beta$-decay isotopes during presupernova evolution were searched from available literature and a microscopic calculation of the decay rates were performed using the proton-neutron quasiparticle random phase approximation (pn-QRPA) theory. As per earlier simulation results electron capture and $\\beta$-decay on certain isotopes of titanium are considered to be important for the presupernova evolution of massive stars. Earlier the stellar electron capture rates and neutrino energy loss rates due to relevant titanium isotopes were presented. In this paper we finally present the $\\beta$-decay rates of key titanium isotopes in stellar environment. The results are also compared against previous calculations. The pn-QRPA $\\beta$-decay rates are bigger at high stellar temperatures and smaller at high stellar densities compared to the large scale shell model results. This study can prove useful for the core-collapse simulators.
Systematic decomposition of the neutrinoless double beta decay operator
Florian Bonnet; Martin Hirsch; Toshihiko Ota; Walter Winter
2014-06-23T23:59:59.000Z
We discuss the systematic decomposition of the dimension nine neutrinoless double beta decay operator, focusing on mechanisms with potentially small contributions to neutrino mass, while being accessible at the LHC. We first provide a (d=9 tree-level) complete list of diagrams for neutrinoless double beta decay. From this list one can easily recover all previously discussed contributions to the neutrinoless double beta decay process, such as the celebrated mass mechanism or "exotics", such as contributions from left-right symmetric models, R-parity violating supersymmetry and leptoquarks. More interestingly, however, we identify a number of new possibilities which have not been discussed in the literature previously. Contact to earlier works based on a general Lorentz-invariant parametrisation of the neutrinoless double beta decay rate is made, which allows, in principle, to derive limits on all possible contributions. We furthermore discuss possible signals at the LHC for mediators leading to the short-range part of the amplitude with one specific example. The study of such contributions would gain particular importance if there were a tension between different measurements of neutrino mass such as coming from neutrinoless double beta decay and cosmology or single beta decay.
Validation and Testing of ENDF/B-VII Decay Data
Gauld, Ian C [ORNL] [ORNL; Pigni, Marco T [ORNL] [ORNL; Ilas, Germina [ORNL] [ORNL
2014-01-01T23:59:59.000Z
The nuclear decay library developed for the ORIGEN code was upgraded from ENDF/B-VI.8 to -VII.0 and released in the SCALE nuclear modeling and simulation code system in 2011. Experience with the ENDF/B-VII.0 library identified serious errors and performance issues in the evaluated decay sublibrary. Initially, errors were identified in the decay scheme for the 238U series, leading to large discrepancies in the gamma emission rate for uranium. Further testing of the fission product decay data revealed significant performance issues with ENDF/B-VII.0 relative to the previous release of ENDF/B-VI. To address the performance issues, the decay data library in SCALE was upgraded to ENDF/B-VII.1 and released as an update for users in 2013. This paper describes the practical impact of the ENDF/B-VII.0 decay data performance issues on common code applications, and the validation and testing performed on the updated ORIGEN libraries developed from the ENDF/B-VII.1 sublibrary.
Top Quark Properties from Top Pair Events and Decays
Andrew G. Ivanov; for the CDF; Dzero Collaborations
2008-10-19T23:59:59.000Z
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.
Multi-particle emission in the decay of 31Ar
G. T. Koldste; B. Blank; M. J. G. Borge; J. A. Briz; M. Carmona-Gallardo; L. M. Fraile; H. O. U. Fynbo; J. Giovinazzo; B. D. Grann; J. G. Johansen; A. Jokinen; B. Jonson; T. Kurturkian-Nieto; J. H. Kusk; T. Nilsson; A. Perea; V. Pesudo; E. Picado; K. Riisager; A. Saastamoinen; O. Tengblad; J. -C. Thomas; J. Van de Walle
2014-02-19T23:59:59.000Z
A multi-hit capacity setup was used to study the decay of the dripline nucleus 31Ar, produced at the ISOLDE facility at CERN. A spectroscopic analysis of the beta-delayed three-proton decay of 31Ar is presented for the first time together with a quantitative analysis of the beta-delayed two-proton-gamma-decay. A new method for determination of the spin of low-lying levels in the beta-proton-daughter 30S using proton-proton angular correlations is presented and used for the level at 5.2 MeV, which is found to be either a 3+ or 4+ level, with the data pointing towards the 3+. The half-life of 31Ar is found to be 15.1(3) ms. An improved analysis of the Fermi beta-strength gives a total measured branching for the beta-3p-decay of 3.60(44) %, which is lower than the theoretical value found to be 4.24(43) %. Finally the strongest gamma-transitions in the decay of 33Ar are shown including a line at 4734(3) keV associated to the decay of the IAS, which has not previously been identified.
Shell model analysis of the neutrinoless double-{beta} decay of {sup 48}Ca
Horoi, Mihai [Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859 (United States); Stoica, Sabin [Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), 407 Atomistilor, Magurele-Bucharest, R-077125 (Romania)
2010-02-15T23:59:59.000Z
The neutrinoless double-{beta} (0{nu}{beta}{beta}) decay process could provide crucial information to determine the absolute scale of neutrino masses, and it is the only one that can establish whether a neutrino is a Dirac or a Majorana particle. A key ingredient for extracting the absolute neutrino masses from 0{nu}{beta}{beta} decay experiments is a precise knowledge of the nuclear matrix elements (NMEs) describing the half-life of this process. We developed a shell model approach for computing the 0{nu}{beta}{beta} decay NME, and we used it to analyze the 0{nu}{beta}{beta} mode of {sup 48}Ca. The dependence of the NME on the short-range correlation parameters, on the average energy of the intermediate states, on the finite-size cutoff parameters, and on the effective interaction used for many-body calculations is discussed.
Time-Dependent CP Violation Effects in Partially Reconstructed $B^0 \\to D^* ?$ Decays
T. Gershon; for the Belle Collaboration
2005-07-08T23:59:59.000Z
We report measurements of time-dependent decay rates for $B^0 \\to D^{*\\mp} \\pi^\\pm$ decays and extraction of CP violation parameters related to $\\phi_3$. We use a partial reconstruction technique, whereby signal events are identified using information only from the primary pion and the charged pion from the decay of the $D^{*\\mp}$. The analysis uses $140 {\\rm fb}^{-1}$ of data accumulated at the $\\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}e^{-}$ collider. We measure the CP violation parameters $S^+ = 0.035 \\pm 0.041 ({\\rm stat}) \\pm 0.018 ({\\rm syst})$ and $S^- = 0.025 \\pm 0.041 ({\\rm stat}) \\pm 0.018 ({\\rm syst})$.
Searches for exotic Higgs boson decays with the ATLAS and CMS experiments
Lagouri, Theodota; The ATLAS collaboration
2015-01-01T23:59:59.000Z
The observed Higgs boson offers an excellent opportunity to look for new physics at LHC. Selected searches for exotic Higgs boson decays with the ATLAS and CMS experiments are presented. The Higgs boson decays to dark vector bosons (Zdark), the Lepton Flavor Violating (LFV) decays, the Flavor Changing Neutral Current (FCNC) decays, the decays to a light pseudo-scalar neutral Higgs boson (a in NMSSM) and the exotic Higgs decays to photon and missing transverse energy signatures are described and their Run-I results are given from both experiments. All the above searches for exotic Higgs boson decays present an alternative way for discovery of Beyond Standard Model (BSM) physics.
Probing Spectator Scattering and Annihilation Corrections in $B_{s}$ $\\to$ $PV$ Decays
Qin Chang; Xiaohui Hu; Junfeng Sun; Yueling Yang
2015-04-20T23:59:59.000Z
Motivated by the recent LHCb measurements on $\\bar{B}_{s}$ $\\to$ $\\pi^{-}K^{*+}$ and $\\bar{B}_{s}$ $\\to$ $K^{\\pm}K^{*\\mp}$ decay modes, we revisit the $B_{s}$ $\\to$ $PV$ decays within QCD factorization framework. The effects of hard-spectator scattering and annihilation corrections are studied in detail. After performing a $\\chi^2$-fit on the end-point parameters $X_A^{i,f}$ ($\\rho_A^{i,f}$, $\\phi_A^{i,f}$) and $X_H$ ($\\rho_H$, $\\phi_H$) with available data, it is found that although some possible mismatches exist, the universalities of $X_A^{i,f}$ and $X_H$ in $B_s$ and $B_{u,d}$ systems are still allowed within theoretical uncertainties and experimental errors. With the end-point parameters gotten from $B_{u,d}$ $\\to$ $PV$ decays, the numerical results and detailed analyses for the observables of $\\bar{B}_{s}$ ${\\to}$ $\\pi K^{\\ast}$, $\\rho K$, $\\pi\\rho$, $\\pi\\phi$ and $K\\phi$ decay modes are presented. In addition, we have identified a few useful observables, especially the ones of $\\bar{B}_{s}$ $\\to$ $\\pi^{0}\\phi$ decay for instance, for probing hard-spectator scattering and annihilation contributions.
Search for a low-mass scalar Higgs boson decaying to a tau pair in single-photon decays of ?(1S)
Cowan, Ray Franklin
We search for a low-mass scalar CP-odd Higgs boson, A[superscript 0], produced in the radiative decay of the upsilon resonance and decaying into a ?[superscript +]?[superscript ?] pair: ?(1S) ? ?A[superscript 0]. The ...
Experimental research of double beta decay of atomic nuclei
F. A. Danevich
2011-12-26T23:59:59.000Z
Results of several double beta decay experiments, performed with the help of low background crystal scintillators, are presented. In particular, the half-life value of the two-neutrino double beta decay of 116-Cd has been measured as 2.9 10^{19} yr, and the new half-life limit on the neutrinoless double beta decay of 116-Cd has been established as >1.7 10^{23} yr at 90%, which corresponds to a restriction on the neutrino mass <1.7 eV. New half-life bounds on the level of 10^{17}-10^{21} yr were set for double beta processes in 64-Zn, 70-Zn, 106-Cd, 108-Cd, 114-Cd, 136-Ce, 138-Ce, 142-Ce, 160-Gd, 180-W, and 186-W by using low-background CdWO4, GSO, and ZnWO4 crystal scintillators. The claim of discovery of the neutrinoless double beta decay of 76-Ge [Mod. Phys. Lett. A 16 (2001) 2409] was analyzed. The demands of the future high sensitivity double beta decay experiments, aiming to observe the neutrinoless double beta decay or to advance restrictions on the neutrino mass to < 0.01 eV, were considered. Requirements for their sensitivity and discovery potential were formulated. Two projects of double beta experiments with a sensitivity on the level of 10^{26}-10^{27} yr (CAMEO and CARVEL projects) were discussed. Scintillation properties and radioactive contamination of CaWO4, ZnWO4, CdWO4, PbWO4, GSO(Ce), CeF3, yttrium-aluminum garnet doped with neodymium (YAG:Nd) crystal scintillators were studied. Applicability of these scintillators to search for double beta decay was discussed.
Constraints on new phenomena via Higgs boson couplings and invisible decays with the ATLAS detector
ATLAS Collaboration
2015-09-02T23:59:59.000Z
The ATLAS experiment at the LHC has measured the Higgs boson couplings and mass, and searched for invisible Higgs boson decays, using multiple production and decay channels with up to 4.7 fb$^{-1}$ of $pp$ collision data at $\\sqrt{s}=7$ TeV and 20.3 fb$^{-1}$ at $\\sqrt{s}=8$ TeV. In the current study, the measured production and decay rates of the observed Higgs boson in the $\\gamma\\gamma$, $ZZ$, $WW$, $Z\\gamma$, $bb$, $\\tau\\tau$, and $\\mu\\mu$ decay channels, along with results from the associated production of a Higgs boson with a top-quark pair, are used to probe the scaling of the couplings with mass. Limits are set on parameters in extensions of the Standard Model including a composite Higgs boson, an additional electroweak singlet, and two-Higgs-doublet models. Together with the measured mass of the scalar Higgs boson in the $\\gamma\\gamma$ and $ZZ$ decay modes, a lower limit is set on the pseudoscalar Higgs boson mass of $m_{A}>370$ GeV in the "hMSSM" simplified Minimal Supersymmetric Standard Model. Results from direct searches for heavy Higgs bosons are also interpreted in the hMSSM. Direct searches for invisible Higgs boson decays in the vector-boson fusion and associated production of a Higgs boson with $W/Z$ ($Z\\to ll$, $W/Z \\to jj$) modes are statistically combined to set an upper limit on the Higgs boson invisible branching ratio of 0.25. The use of the measured visible decay rates in a more general coupling fit improves the upper limit to 0.23, constraining a Higgs portal model of dark matter.
The contribution of light Majorana neutrinos to neutrinoless double beta decay and cosmology
Dell'Oro, Stefano; Viel, Matteo; Vissani, Francesco
2015-01-01T23:59:59.000Z
Cosmology is making impressive progress and it is producing stringent bounds on the sum of the neutrino masses {\\Sigma}, a parameter of great importance for the current laboratory experiments. In this letter, we exploit the potential relevance of the analysis of Palanque-Delabrouille et al. [JCAP 1502, 045 (2015)] to the neutrinoless double beta decay (0\
The contribution of light Majorana neutrinos to neutrinoless double beta decay and cosmology
Stefano Dell'Oro; Simone Marcocci; Matteo Viel; Francesco Vissani
2015-05-11T23:59:59.000Z
Cosmology is making impressive progress and it is producing stringent bounds on the sum of the neutrino masses {\\Sigma}, a parameter of great importance for the current laboratory experiments. In this letter, we exploit the potential relevance of the analysis of Palanque-Delabrouille et al. [JCAP 1502, 045 (2015)] to the neutrinoless double beta decay (0\
Bose-Einstein correlations in K K pairs from Z 0 decays into two hadronic jets
Bose-Einstein correlations in K #6; K #6; pairs from Z 0 decays into two hadronic jets The OPAL collaboration Abstract Bose-Einstein correlations in pairs of charged kaons produced in a sample of 3.9 million function. The parameters of the Bose- Einstein correlations were measured to be #21; = 0.82 #6; 0.22 + 0
Probing the Goldstone equivalence theorem in Heavy Weak Doublet Decays
Dutta, Bhaskar; Sanford, David; Walker, Joel W
2015-01-01T23:59:59.000Z
This paper investigates the decays from heavy higgsino-like weak-doublets into Z, h bosons and missing particles. When pair-produced at the LHC, the subsequent Z, h to 2l, 2b decays in the doublet decay cascade can yield 4l, 2l 2b, and 4b + MET + jets final states. Mutual observation of any two of these channels would provide information on the the associated doublets' decay branching fractions into a Z or h, thereby probing the Goldstone equivalence relation, shedding additional light on the Higgs sector of beyond the Standard Model theories, and facilitating the discrimination of various contending models, in turn. We compare the Z/h decay ratio expected in the Minimal Supersymmetric model, the Next-to Minimal Supersymmetric model and a minimal singlet-doublet dark matter model. Additionally, we conduct a full Monte Carlo analysis of the prospects for detecting the targeted final states during 14 TeV running of the LHC in the context of a representative NMSSM benchmark model.
137 Ba Double Gamma Decay Measurement with GAMMASPHERE
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Merchán, E.; Moran, K.; Lister, C. J.; Chowdhury, P.; McCutchan, E. A.; Greene, J. P.; Zhu, S.; Lauritsen, T.; Carpenter, M. P.; Shearman, R.
2015-05-28T23:59:59.000Z
The study of the electromagnetic moments (EM), and decay probability, provides detailed information about nuclear wave functions. The well-know properties of EM interactions are good for extracting information about the motion of nucleons. Higher order EM processes always occur, but are usually too weak to be measured. In the case of a 0+ ? 0+ transitions, where a single gamma transition is forbidden, the simultaneous emission of two ?-rays has been studied. An interesting opportunity to further investigate 2-photon emission phenomena is by using a standard 137Cs source populating, via ?-decay, the J? = 11/2- isomeric state at 662 keVmore »in 137Ba. In this case, two photon process can have contributions from quadrupole-quadrupole or dipole-octupole multipolarities in direct competition with the high multipolarity M4 decay. Since the yield of the double gamma decay is around six orders of magnitude less than the first order transition, very good statistics are needed in order to observe the phenomena and great care must be taken to suppress the first-order decay. The Gammasphere array is ideal since its configuration allows a good coverage of the angular distribution and the Compton events can be suppressed. Nevertheless the process to understand and eliminate the Compton background is a challenge. Geant4 simulations were carried out to help understand and correct for those factors.« less
Anatomy of three-body decay III. Energy distributions
E. Garrido; D. V. Fedorov; A. S. Jensen; H. O. U. Fynbo
2005-12-01T23:59:59.000Z
We address the problem of calculating momentum distributions of particles emerging from the three-body decay of a many-body resonance. We show that these distributions are determined by the asymptotics of the coordinate-space complex-energy wave-function of the resonance. We use the hyperspherical adiabatic expansion method where all lengths are proportional to the hyperradius. The structures of the resonances are related to different decay mechanisms. For direct decay all inter-particle distances increase proportional to the hyperradius at intermediate and large distances. Sequential three-body decay proceeds via spatially confined quasi-stationary two-body configurations. Then two particles remain close while the third moves away. The wave function may contain mixtures which produce coherence effects at small distances, but the energy distributions can still be added incoherently. Two-neutron halos are discussed in details and illustrated by the $2^+$ resonance in $^{6}$He. The dynamic evolution of the decay process is discussed.
Dark Radiation from Particle Decays during Big Bang Nucleosynthesis
Menestrina, Justin L
2011-01-01T23:59:59.000Z
Cosmic microwave background (CMB) observations suggest the possibility of an extra dark radiation component, while the current evidence from big bang nucleosynthesis (BBN) is more ambiguous. Dark radiation from a decaying particle can affect these two processes differently. Early decays add an additional radiation component to both the CMB and BBN, while late decays can alter the radiation content seen in the CMB while having a negligible effect on BBN. Here we quantify this difference and explore the intermediate regime by examining particles decaying during BBN, i.e., particle lifetimes \\tau_X satisfying 0.1 sec 1000 sec), \\Delta N_{BBN} is dominated by the energy density of the nonrelativistic particles before they decay, so that \\Delta N_{BBN} remains nonzero and becomes independent of the particle lifetime. By varying both the particle energy density and lifetime, one can obtain any desired combination of \\Delta N_{BBN} and \\Delta N_{CMB}, subject to the constraint that \\Delta N_{CMB} >= \\Delta N_{BBN}.
Sensitivity studies for the main r process: ?-decay rates
Mumpower, M.; Cass, J.; Passucci, G.; Aprahamian, A. [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)] [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Surman, R. [Department of Physics and Astronomy, Union College, Schenectady, New York 12308 (United States)] [Department of Physics and Astronomy, Union College, Schenectady, New York 12308 (United States)
2014-04-15T23:59:59.000Z
The pattern of isotopic abundances produced in rapid neutron capture, or r-process, nucleosynthesis is sensitive to the nuclear physics properties of thousands of unstable neutron-rich nuclear species that participate in the process. It has long been recognized that the some of the most influential pieces of nuclear data for r-process simulations are ?-decay lifetimes. In light of experimental advances that have pushed measurement capabilities closer to the classic r-process path, we revisit the role of individual ?-decay rates in the r process. We perform ?-decay rate sensitivity studies for a main (A > 120) r process in a range of potential astrophysical scenarios. We study the influence of individual rates during (n, ?)-(?, n) equilibrium and during the post-equilibrium phase where material moves back toward stability. We confirm the widely accepted view that the most important lifetimes are those of nuclei along the r-process path for each astrophysical scenario considered. However, we find in addition that individual ?-decay rates continue to shape the final abundance pattern through the post-equilibrium phase, for as long as neutron capture competes with ? decay. Many of the lifetimes important for this phase of the r process are within current or near future experimental reach.
Charmless 3-body B Decays: Resonant and Nonresonant contributions
Cheng, Hai-Yang
2007-01-01T23:59:59.000Z
Charmless 3-body decays of $B$ mesons are studied using a simple model based on the framework of the factorization approach. We have identified a large source of the nonresonant signal in the matrix elements of scalar densities, e.g. $$. This explains the dominance of the nonresonant background in $B\\to KKK$ decays, the sizable nonresonant fraction of order $(35\\sim 40)%$ in $K^-\\pi^+\\pi^-$ and $\\bar K^0\\pi^+\\pi^-$ modes and the smallness of nonresonant rates in $B\\to \\pi\\pi\\pi$ decays. We have computed the resonant and nonresonant contributions to charmless 3-body decays and determined the rates for the quasi-two-body decays $B\\to VP$ and $B\\to SP$. Time-dependent CP asymmetries $\\sin2\\beta_{\\rm eff}$ and $A_{CP}$ in $K^+K^-K_S,K_SK_SK_S,K_S\\pi^+\\pi^-$ and $K_S\\pi^0\\pi^0$ modes are estimated.
Cosmology with a Decaying Vacuum Energy Parametrization Derived from Quantum Mechanics
Szydlowski, Marek; Urbanowski, Krzysztof
2015-01-01T23:59:59.000Z
Within the quantum mechanical treatment of the decay problem one finds that at late times $t$ the survival probability of an unstable state cannot have the form of an exponentially decreasing function of time $t$ but it has an inverse power-like form. This is a general property of unstable states following from basic principles of quantum theory. The consequence of this property is that in the case of false vacuum states the cosmological constant becomes dependent on time: $\\Lambda - \\Lambda_{\\text{bare}}\\equiv \\Lambda(t) -\\Lambda_{\\text{bare}} \\sim 1/t^{2}$. We construct the cosmological model with decaying vacuum energy density and matter for solving the cosmological constant problem and the coincidence problem. We show the equivalence of the proposed decaying false vacuum cosmology with the $\\Lambda(t)$ cosmologies (the $\\Lambda(t)$CDM models). The cosmological implications of the model of decaying vacuum energy (dark energy) are discussed. We constrain the parameters of the model with decaying vacuum usin...
Constraints on new phenomena via Higgs boson couplings and invisible decays with the ATLAS detector
Aad, Georges; ATLAS Collaboration; Abdallah, Jalal; Abdinov, Ovsat; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agricola, Johannes; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; ?lvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Baca, Matthew John; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansil, Hardeep Singh; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bieniek, Stephen Paul; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina
2015-01-01T23:59:59.000Z
The ATLAS experiment at the LHC has measured the Higgs boson couplings and mass, and searched for invisible Higgs boson decays, using multiple production and decay channels with up to 4.7 fb$^{-1}$ of $pp$ collision data at $\\sqrt{s}=7$ TeV and 20.3 fb$^{-1}$ at $\\sqrt{s}=8$ TeV. In the current study, the measured production and decay rates of the observed Higgs boson in the $\\gamma\\gamma$, $ZZ$, $WW$, $Z\\gamma$, $bb$, $\\tau\\tau$, and $\\mu\\mu$ decay channels, along with results from the associated production of a Higgs boson with a top-quark pair, are used to probe the scaling of the couplings with mass. Limits are set on parameters in extensions of the Standard Model including a composite Higgs boson, an additional electroweak singlet, and two-Higgs-doublet models. Together with the measured mass of the scalar Higgs boson in the $\\gamma\\gamma$ and $ZZ$ decay modes, a lower limit is set on the pseudoscalar Higgs boson mass of $m_{A}>370$ GeV in the ``hMSSM'' simplified Minimal Supersymmetric Standard Model...
Charmless $B \\to PV, VV $ decays and new physics effects in the mSUGRA model
Wenjuan Zou; Zhenjun Xiao
2005-10-24T23:59:59.000Z
By employing the QCD factorization approach, we calculate the new physics contributions to the branching radios of the two-body charmless $ B \\to PV$ and $B \\to VV$ decays in the framework of the minimal supergravity (mSUGRA) model. we choose three typical sets of the mSUGRA input parameters in which the Wilson coefficient $C_{7\\gamma}(m_b)$ can be either SM-like (the case A and C) or has a flipped-sign (the case B). We found numerically that (a) the SUSY contributions are always very small for both case A and C; (b) for those tree-dominated decays, the SUSY contributions in case B are also very small; (c) for those QCD penguin-dominated decay modes, the SUSY contributions in case B can be significant, and can provide an enhancement about $30% \\sim 260%$ to the branching ratios of $B \\to K^*(\\pi,\\phi,\\rho)$ and $K \\phi$ decays, but a reduction about $30% \\sim 80%$ to $ B\\to K(\\rho, \\omega)$ decays; and (d) the large SUSY contributions in the case B may be masked by the large theoretical errors dominated by the uncertainty from our ignorance of calculating the annihilation contributions in the QCD factorization approach.
Spectral Content of 22Na/44Ti Decay Data: Implications for a Solar Influence
Daniel O'Keefe; Brittany L. Morreale; Robert H. Lee; John B. Buncher; Ephraim Fischbach; Tom Gruenwald; Jere H. Jenkins; Daniel Javorsek II; Peter A. Sturrock
2012-12-10T23:59:59.000Z
We report a reanalysis of data on the measured decay rate ratio $^{22}$Na/$^{44}$Ti which were originally published by Norman et al., and interpreted as supporting the conventional hypothesis that nuclear decay rates are constant and not affected by outside influences. We find upon a more detailed analysis of both the amplitude and the phase of the Norman data that they actually favor the presence of an annual variation in $^{22}$Na/$^{44}$Ti, albeit weakly. Moreover, this conclusion holds for a broad range of parameters describing the amplitude and phase of an annual sinusoidal variation in these data. The results from this and related analyses underscore the growing importance of phase considerations in understanding the possible influence of the Sun on nuclear decays. Our conclusions with respect to the phase of the Norman data are consistent with independent analyses of solar neutrino data obtained at Super-Kamiokande-I and the Sudbury Neutrino Observatory (SNO).
Latest results of NEXT-DEMO, the prototype of the NEXT 100 double beta decay experiment
Serra, L; Martin-Albo, J; Sorel, M; Gomez-Cadenas, J J
2014-01-01T23:59:59.000Z
NEXT-DEMO is a 1:4.5 scale prototype of the NEXT100 detector, a high-pressure xenon gas TPC that will search for the neutrinoless double beta decay of $^{136}$Xe. X-ray energy depositions produced by the de-excitation of Xenon atoms after the interaction of gamma rays from radioactive sources have been used to characterize the response of the detector obtaining the spatial calibration needed for close-to-optimal energy resolution. Our result, 5.5% FWHM at 30 keV, extrapolates to 0.6% FWHM at the Q value of $^{136}$Xe. Additionally, alpha decays from radon have been used to measure several detection properties and parameters of xenon gas such as electron-ion recombination, electron drift velocity, diffusion and primary scintillation light yield. Alpha spectroscopy is also used to quantify the activity of radon inside the detector, a potential source of background for most double beta decay experiments.
Nonlinear classical model for the decay widths of isoscalar giant monopole resonances
Papachristou, P. K.; Mavrommatis, E.; Diakonos, F. K. [Department of Physics, University of Athens, GR-15771, Athens (Greece); Constantoudis, V. [Institute of Microelectronics (IMEL), NCSR 'Demokritos', P. O. Box 60228, Aghia Paraskevi, Attiki, Greece 15310 and Physics Department, National Technical University, Athens (Greece); Wambach, J. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstr. 9, D-64289 Darmstadt (Germany)
2008-04-15T23:59:59.000Z
The decay of the isoscalar giant monopole resonance (ISGMR) in nuclei is studied by means of a nonlinear classical model consisting of several noninteracting nucleons (particles) moving in a potential well with an oscillating nuclear surface (wall). The motion of the nuclear surface is described by means of a collective variable that appears explicitly in the Hamiltonian as an additional degree of freedom. The total energy of the system is therefore conserved. Although the particles do not directly interact with each other, their motions are indirectly coupled by means of their interaction with the moving nuclear surface. We consider as free parameters in this model the degree of collectivity and the fraction of nucleons that participate to the decay of the collective excitation. Specifically, we have calculated the decay width of the ISGMR in the spherical nuclei {sup 208}Pb, {sup 144}Sm, {sup 116}Sn, and {sup 90}Zr. Despite its simplicity and its purely classical nature, the model reproduces the trend of the experimental data that show that with increasing mass number the decay width decreases. Moreover the experimental results (with the exception of {sup 90}Zr) can be well fitted using appropriate values for the free parameters mentioned above. It is also found that these values allow for a good description of the experimentally measured {sup 112}Sn and {sup 124}Sn decay widths. In addition, we give a prediction for the decay width of the exotic isotope {sup 132}Sn for which there is experimental interest. The agreement of our results with the corresponding experimental data for medium-heavy nuclei is dictated by the underlying classical mechanics, i.e., the behavior of the maximum Lyapunov exponent as a function of the system size.
Short-range correlations and neutrinoless double beta decay
M. Kortelainen; O. Civitarese; J. Suhonen; J. Toivanen
2007-01-18T23:59:59.000Z
In this work we report on the effects of short-range correlations upon the matrix elements of neutrinoless double beta decay. We focus on the calculation of the matrix elements of the neutrino-mass mode of neutrinoless double beta decays of 48Ca and 76Ge. The nuclear-structure components of the calculation, that is the participant nuclear wave functions, have been calculated in the shell-model scheme for 48Ca and in the proton-neutron quasiparticle random-phase approximation (pnQRPA) scheme for 76Ge. We compare the traditional approach of using the Jastrow correlation function with the more complete scheme of the unitary correlation operator method (UCOM). Our results indicate that the Jastrow method vastly exaggerates the effects of short-range correlations on the neutrinoless double beta decay nuclear matrix elements.
Chiral Two-body Currents and Neutrinoless Double Beta Decay
Menendez, Javier [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany)
2011-12-16T23:59:59.000Z
The nuclear matrix elements (NMEs) of neutrinoless double-beta (0{nu}{beta}{beta}) decay are studied using weak currents derived in the framework of chiral effective field theory. Apart from the standard one-body (1b) currents, it is shown that two-body (2b) currents contribute to weak processes. The normal-ordered 1b part of 2b currents modifies the Gamow-Teller (GT){sigma}{tau}{sup -} part of the 1b current, contributing to the well-known quenching of GT single-{beta} decays. The momentum-transfer dependence of the quenching due to 2b currents is also predicted. Therefore, including 2b currents allows to address, microscopically, the problem of the axial weak coupling (g{sub A}) value, which is the biggest uncertainty in the 0{nu}{beta}{beta} decay NME calculations for all available methods.
Double beta decay, Majorana neutrinos, and neutrino mass
Avignone, Frank T. III; Elliott, Steven R.; Engel, Jonathan [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina 29208 (United States); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599-3255 (United States)
2008-04-15T23:59:59.000Z
The theoretical and experimental issues relevant to neutrinoless double beta decay are reviewed. The impact that a direct observation of this exotic process would have on elementary particle physics, nuclear physics, astrophysics, and cosmology is profound. Now that neutrinos are known to have mass and experiments are becoming more sensitive, even the nonobservation of neutrinoless double beta decay will be useful. If the process is actually observed, we will immediately learn much about the neutrino. The status and discovery potential of proposed experiments are reviewed in this context, with significant emphasis on proposals favored by recent panel reviews. The importance of and challenges in the calculation of nuclear matrix elements that govern the decay are considered in detail. The increasing sensitivity of experiments and improvements in nuclear theory make the future exciting for this field at the interface of nuclear and particle physics.
Heavy Sterile Neutrinos and Neutrinoless Double Beta Decay
Manimala Mitra; Goran Senjanovic; Francesco Vissani
2012-05-17T23:59:59.000Z
Sterile neutrinos of mass up to a few tens of TeV can saturate the present experimental bound of neutrinoless double beta decay process. Due to the updated nuclear matrix elements, the bound on mass and mixing angle is now improved by one order of magnitude. We have performed a detailed analysis of neutrinoless double beta decay for the minimal Type I seesaw scenario. We have shown that in spite of the naive expectation that the light neutrinos give the dominant contribution, sterile neutrinos can saturate the present experimental bound of neutrinoless double beta decay process. However, in order to be consistent with radiative stability of light neutrino masses, the mass scale of sterile neutrinos should be less than 10 GeV.
Results of the double beta decay experiment NEMO-3
Tretyak, V. I. [Joint Institute for Nuclear Research, 6 Joliot Curie, Dubna (Russian Federation); Collaboration: NEMO-3 Collaboration
2013-12-30T23:59:59.000Z
The double beta decay experiment NEMO-3 has taken data from February 2003 to January 2011. The two-neutrino decay half lives were measured for seven different isotopes ({sup 100}Mo, {sup 82}Se, {sup 116}Cd, {sup 150}Nd, {sup 96}Zr, {sup 48}Ca and {sup 130}Te). No evidence for neutrinoless double beta decay is observed. The 0??? half-life limits are found to be T{sub 1/2}{sup 0?}({sup 100}Mo)>1.0×10{sup 24}yr(90%C.L.) and T{sub 1/2}{sup 0?}({sup 82}Se)>3.2×10{sup 23}yr(90%C.L.)
Numerical Study of Induced False Vacuum Decay at High Energies
A. N. Kuznetsov; P. G. Tinyakov
1995-11-02T23:59:59.000Z
We calculate numerically the probability $\\exp[ {1\\over\\lambda} F(E/E_{sph},N/N_{sph})]$ of the false vacuum decay in the massive four-dimensional $-\\lambda\\phi^4$ model from multiparticle initial states with fixed number of particles $N$ and energy $E$ greater than the height of the barrier $E_{sph}$. We find that at $E\\lsim 3E_{sph}$ and $N\\lsim 0.4N_{sph}$ the decay is classically forbidden and thus is exponentially suppressed. We argue that the classically forbidden region extends at small $N$ at least up to $E\\sim 10 E_{sph}$ and, most likely, to all energies. Our data suggest that the false vacuum decay induced by two-particle collisions is exponentially suppressed at all energies.
Top-quark processes at NLO in production and decay
Campbell, John M.; Ellis, R.Keith
2012-04-01T23:59:59.000Z
We describe the implementation of top production and decay processes in the parton-level Monte Carlo program MCFM. By treating the top quark as being on-shell, we can factorize the amplitudes for top-pair production, s-channel single-top production, and t-channel single-top production into the product of an amplitude for production and an amplitude for decay. In this way we can retain all spin correlations. Both the production and the decay amplitudes are calculated consistently at next-to-leading order in alpha_s. The full dependence on the b-quark mass is also kept. Phenomenological results are presented for various kinematic distributions at the LHC and for the top quark forward-backward asymmetry at the Tevatron.
Updated measurements of hadronic B decays at CDF
Morello, Michael J.
2012-01-01T23:59:59.000Z
The CDF experiment at the Tevatron p{bar p} collider established that extensive and detailed exploration of the b-quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from e{sup +}e{sup -} colliders. This provides a rich, and highly rewarding program that has currently reached full maturity. In the following I report some recent results on hadronic decays: the evidence for the charmless annihilation decay mode B{sub s}{sup 0} {yields} {pi}{sup +}{pi}{sup -}, and the first reconstruction in hadron collisions of the suppressed decays B{sup -} {yields} D({yields} K{sup +}{pi}{sup 0})K{sup -} and B{sup -} {yields} D({yields} K{sup +} {pi}{sup -}){pi}{sup -}.
Exponential Time Decay Estimates for the Landau Equation on Torus
Kung-Chien Wu
2013-01-04T23:59:59.000Z
We study the time decay estimates for the linearized Landau equation on torus when the initial perturbation is not necessarily smooth. Our result reveals the kinetic and fluid aspects of the equation. We design a Picard-type iteration and Mixture lemma for constructing the increasingly regular kinetic like waves, they are carried by transport equations and have exponential time decay rate. The fluid like waves are constructed as part of the long-wave expansion in the spectrum of the Fourier mode for the space variable and the time decay rate depends on the size of the domain. The Mixture lemma plays an important role in this paper, this lemma is parallel to Boltzmann equation but the proof is more challenge.
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.; Bertani, M.; Bian, J. M.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Cao, G. F.; Cao, X. X.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, Y.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denysenko, I.; Destefanis, M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Duan, M. Y.; Fan, R. R.; Fang, J.; Fang, S. S.; Feng, C. Q.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Greco, M.; Grishin, S.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y. P.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Heng, Y. K.; Hou, Z. L.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, B.; Huang, G. M.; Huang, J. S.; Huang, X. T.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, X. B.; Ji, X. L.; Jia, L. K.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kavatsyuk, M.; Komamiya, S.; Kuehn, W.; Lange, J. S.; Leung, J. K. C.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, Lei; Li, N. B.; Li, Q. J.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Liao, X. T.; Liu, B. J.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, C. Y.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, G. C.; Liu, H.; Liu, H. B.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K.; Liu, K. Y.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. H.; Liu, Y. B.; Liu, Y. W.; Liu, Yong; Liu, Z. A.; Liu, Z. Q.; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, T.; Ma, X.; Ma, X. Y.; Maggiora, M.; Malik, Q. A.; Mao, H.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Mitchell, R. E.; Mo, X. H.; Muchnoi, N. Yu.; Nefedov, Y.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pelizaeus, M.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pun, C. S. J.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, X. S.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schulze, J.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Sonoda, S.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. D.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tang, X. F.; Tian, H. L.; Toth, D.; Varner, G. S.; Wan, X.; Wang, B. Q.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q.; Wang, S. G.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Wen, Q. G.; Wen, S. P.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, W.; Wu, Z.; Xiao, Z. J.; Xie, Y. G.; Xu, G. F.; Xu, G. M.; Xu, H.; Xu, Y.; Xu, Z. R.; Xu, Z. Z.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, M.; Yang, T.; Yang, Y.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, L.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, L.; Zhang, S. H.; Zhang, T. R.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, H. S.; Zhao, Jiawei; Zhao, Jingwei; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhao, Z. L.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zheng, Z. P.; Zhong, B.; Zhong, J.; Zhong, L.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, X. W.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Zuo, J. X.; Zweber, P.
2011-08-01T23:59:59.000Z
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.
Isospin mixing and energy distributions in three-body decay
E. Garrido; D. V. Fedorov; H. O. U. Fynbo; A. S. Jensen
2007-03-21T23:59:59.000Z
The structure of the second 2$^+$ resonance in $^{6}$Li is investigated with special emphasis on its isospin 0 components. The wave functions are computed in a three-body model ($\\alpha$+$n$+$p$) using the hyperspherical adiabatic expansion method combined with complex scaling. In the decay into three free particles the symmetry conserving short-range interaction dominates at short distance whereas the symmetry breaking Coulomb interaction dominates at intermediate and large distances resulting in substantial isospin mixing. We predict the mixing and the energy distributions of the fragments after decay. Computations are consistent with available experiments. We conjecture that nuclear three-body decays frequently produce such large isospin mixing at large distance where the energy distributions. are determined.
Measurement of Prominent {eta}-Decay Branching Fractions
Lopez, A.; Mehrabyan, S.; Mendez, H.; Ramirez, J. [University of Puerto Rico, Mayaguez, Puerto Rico 00681 (Puerto Rico); Ge, J. Y.; Miller, D. H.; Sanghi, B.; Shipsey, I. P. J.; Xin, B. [Purdue University, West Lafayette, Indiana 47907 (United States); Adams, G. S.; Anderson, M.; Cummings, J. P.; Danko, I.; Hu, D.; Moziak, B.; Napolitano, J. [Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); He, Q.; Insler, J.; Muramatsu, H.; Park, C. S. [University of Rochester, Rochester, New York 14627 (United States)] (and others)
2007-09-21T23:59:59.000Z
The decay {psi}(2S){yields}{eta}J/{psi} is used to measure, for the first time, all prominent {eta}-meson branching fractions with the same experiment in the same dataset, thereby providing a consistent treatment of systematics across branching fractions. We present results for {eta} decays to {gamma}{gamma}, {pi}{sup +}{pi}{sup -}{pi}{sup 0}, 3{pi}{sup 0}, {pi}{sup +}{pi}{sup -}{gamma} and e{sup +}e{sup -}{gamma}, accounting for 99.9% of all {eta} decays. The precision of several of the branching fractions and their ratios is improved. Two channels, {pi}{sup +}{pi}{sup -}{gamma} and e{sup +}e{sup -}{gamma}, show results that differ at the level of three standard deviations from those previously determined.
Lorentz-symmetry violating decays in a medium
Nieves, Jose F.; Pal, Palash B. [Laboratory of Theoretical Physics, Department of Physics, P.O. Box 23343, University of Puerto Rico, Rio Piedras, 00931-3343 (Puerto Rico); Saha Institute of Nuclear Physics, 1/AF Bidhan-Nagar, Calcutta 700064 (India)
2008-06-01T23:59:59.000Z
Various decay processes, such as the decay of a spin-1 particle into two photons or the gravitational decay of a spin-1/2 fermion, are forbidden in the vacuum by a combination of requirements, including angular momentum conservation, Lorentz invariance, and gauge invariance. We show that such processes can occur in a medium, such as a thermal background of particles, even if it is homogeneous and isotropic. We carry out a model-independent analysis of the vertex function for such processes in terms of a set of form factors, and show that the amplitude can be nonzero while remaining consistent with the symmetry principles mentioned above. The results simulate Lorentz symmetry violating effects, although in this case they arise from completely Lorentz-invariant physics.
Consequences of neutrinoless double beta decay and WMAP
H. V. Klapdor-Kleingrothaus; U. Sarkar
2003-04-03T23:59:59.000Z
Observation of the neutrinoless double beta decay ($\\0n$) has established that there is lepton number violation in nature and the neutrino masses are Majorana in nature. It also gives the absolute mass of the neutrinos and discriminates between different models of neutrino masses. The allowed amount of lepton number violation puts severe constraints on some possible new physics beyond the standard model. The recent results from WMAP are consistent with the consequences of the neutrinoless double beta decay. They improve some of these constraints very marginally, which we shall summarise here. We mention the new physics which are not affected by WMAP and could make both these limits from the neutrinoless double beta decay and WMAP consistent.
Study of J?decaying into ?p \\bar p
BES Collaboration
2007-12-03T23:59:59.000Z
The decay $J/\\psi \\to \\omega p \\bar p$ is studied using a $5.8 \\times 10^7$ $J/\\psi$ event sample accumulated with the BES II detector at the Beijing electron-positron collider. The decay branching fraction is measured to be $B(J/\\psi \\to \\omega p \\bar p)=(9.8\\pm 0.3\\pm 1.4)\\times 10^{-4}$. No significant enhancement near the $p\\bar p$ mass threshold is observed, and an upper limit of $B(J/\\psi \\to \\omega X(1860))B(X(1860)\\to p\\bar p)$$ $$p\\bar p$ mass spectrum in $J/\\psi \\to \\gamma p \\bar p$ decays.
Double Beta Decay, Majorana Neutrinos, and Neutrino Mass
Frank T. Avignone III; Steven R. Elliott; Jonathan Engel
2007-11-26T23:59:59.000Z
The theoretical and experimental issues relevant to neutrinoless double-beta decay are reviewed. The impact that a direct observation of this exotic process would have on elementary particle physics, nuclear physics, astrophysics and cosmology is profound. Now that neutrinos are known to have mass and experiments are becoming more sensitive, even the non-observation of neutrinoless double-beta decay will be useful. If the process is actually observed, we will immediately learn much about the neutrino. The status and discovery potential of proposed experiments are reviewed in this context, with significant emphasis on proposals favored by recent panel reviews. The importance of and challenges in the calculation of nuclear matrix elements that govern the decay are considered in detail. The increasing sensitivity of experiments and improvements in nuclear theory make the future exciting for this field at the interface of nuclear and particle physics.
Q value of the 100Mo Double-Beta Decay
S. Rahaman; V. -V. Elomaa; T. Eronen; J. Hakala; A. Jokinen; J. Julin; A. Kankainen; A. Saastamoinen; J. Suhonen; C. Weber; J. Äystö
2007-12-20T23:59:59.000Z
Penning trap measurements using mixed beams of 100Mo - 100Ru and 76Ge - 76Se have been utilized to determine the double-beta decay Q-values of 100Mo and 76Ge with uncertainties less than 200 eV. The value for 76Ge, 2039.04(16) keV is in agreement with the published SMILETRAP value. The new value for 100Mo, 3034.40(17) keV is 30 times more precise than the previous literature value, sufficient for the ongoing neutrinoless double-beta decay searches in 100Mo. Moreover, the precise Q-value is used to calculate the phase-space integrals and the experimental nuclear matrix element of double-beta decay.
Decaying Neutrinos and the Flattening of the Galactic Halo
D. W. Sciama
1997-04-10T23:59:59.000Z
The recently constructed Dehnen-Binney set of mass models for the Galaxy is used to show that the decaying neutrino theory for the ionisation of the interstellar medium (Sciama 1990a, 1993) requires the neutrino halo of the Galaxy to be as flattened as is observationally permitted (axial ratio q=0.2 or shape E8). The argument involves an evaluation of the contribution of red-shifted decay photons from the cosmological distribution of neutrinos to the extragalactic diffuse background at 1500 Angstroms. This contribution must be as large as is observationally permitted. These two requirements depend on the decay lifetime in potentially conflicting ways. For consistency to be achieved the lifetime must lie within 30 per cent of 10^23 seconds.
Helium-cluster decay widths of molecular states in beryllium and carbon isotopes
J. C. Pei; F. R. Xu
2007-02-01T23:59:59.000Z
The $\\alpha$ particle and $^6$He emissions from possible molecular states in beryllium and carbon isotopes have been studied using a mean-field-type cluster potential. Calculations can reproduce well the $\\alpha$-decay widths of excited states in $^{8}$Be, $^{12}$C and $^{20}$Ne. For the nucleus $^{10}$Be, we discussed the $\\alpha$-decay widths with different shapes or decay modes, in order to understand the very different decay widths of two excited states. The widths of $^{6}$He decay from $^{12}$Be and $\\alpha$ decays from $^{13,14}$C are predicted, which could be useful for future experiments.
Consistency test of neutrinoless double beta decay with one isotope
Michael Duerr; Manfred Lindner; Kai Zuber
2011-11-17T23:59:59.000Z
We discuss a consistency test which makes it possible to discriminate unknown nuclear background lines from neutrinoless double beta decay with only one isotope. By considering both the transition to the ground state and to the first excited $0^+$ state, a sufficiently large detector can reveal if neutrinoless double beta decay or some other nuclear physics process is at work. Such a detector could therefore simultaneously provide a consistency test for a certain range of Majorana masses and be sensitive to lower values of the effective Majorana mass.
Nuclear Structure Aspects of the Neutrinoless Double Beta Decay
E. Caurier; F. Nowacki; A. Poves
2008-01-09T23:59:59.000Z
In this article, we analyze some nuclear structure aspects of the neutrinoless double beta decay nuclear matrix elements (NME), in the framework of the Interacting Shell Model. We give results for the decays of 48Ca, 76Ge, 82Se, 124Sn, 128Te, 130Te, and 136Xe, using improved effective interactions and valence spaces. We examine the dependence of the NME's on the effective interaction and the valence space, and analyze the effects of the short range correlations and the finite size of the nucleon. Finally we study the influence of the deformation on the values of the NME's.
Consistency test of neutrinoless double beta decay with one isotope
Duerr, Michael; Lindner, Manfred [Max-Planck-Institut fuer Kernphysik, Postfach 10 39 80, 69029 Heidelberg (Germany); Zuber, Kai [Technical University Dresden, Institut fuer Kern- und Teilchenphysik, 01069 Dresden (Germany)
2011-11-01T23:59:59.000Z
We discuss a consistency test which makes it possible to discriminate unknown nuclear background lines from neutrinoless double beta decay with only one isotope. By considering both the transition to the ground state and to the first excited 0{sup +} state, a sufficiently large detector can reveal if neutrinoless double beta decay or some other nuclear physics process is at work. Such a detector could therefore simultaneously provide a consistency test for a certain range of Majorana masses and be sensitive to lower values of the effective Majorana mass
The GERDA Neutrinoless Double Beta-Decay Experiment
Majorovits, Bela A. [Max Planck Institut fuer Physik, Foehringer Ring 6, 80805 Munich (Germany)
2007-10-12T23:59:59.000Z
Neutrinoless double beta (0{nu}{beta}{beta})-decay is the key process to gain understanding of the nature of neutrinos. The GErmanium Detector Array (GERDA) is designed to search for 0{nu}{beta}{beta}-decay of the isotope {sup 76}Ge. Germanium crystals enriched in {sup 76}Ge, acting as source and detector simultaneously, will be submerged directly into an ultra pure cooling medium that also serves as a radiation shield. This concept will allow for a reduction of the background by up to two orders of magnitudes with respect to earlier experiments.
Double-{beta} decay Q value of {sup 150}Nd
Kolhinen, V. S.; Eronen, T.; Gorelov, D.; Hakala, J.; Jokinen, A.; Kankainen, A.; Moore, I. D.; Rissanen, J.; Saastamoinen, A.; Suhonen, J.; Aeystoe, J. [Department of Physics, P. O. Box 35 (YFL), FI-40014 University of Jyvaeskylae (Finland)
2010-08-15T23:59:59.000Z
The double-{beta} decay Q value of {sup 150}Nd was determined by using the JYFLTRAP Penning trap mass spectrometer. The measured mass difference between {sup 150}Nd and {sup 150}Sm is 3371.38(20) keV. This new value deviates by 3.7 keV from the previously adopted value of 3367.7(22) keV and is a factor of 10 more precise. Accurate knowledge of this Q value is important because {sup 150}Nd is a primary candidate to be used in the search for neutrinoless double-{beta} decay modes in several experiments.
Testing for new physics in singly Cabibbo suppressed D decays
Yuval Grossman; Alexander L. Kagan; Jure Zupan
2012-04-16T23:59:59.000Z
We devise tests for a new physics origin of the recently measured direct CP violation in singly Cabibbo suppressed D decays. The tests take the form of sum rules for the CP asymmetries in various D decays. They are based on the fact that within the standard model CP violation arises from interference of the dominant tree amplitudes with the Delta I=1/2 penguin amplitudes. The sum rules would be violated if the observed CP violation is due to new physics contributions to the effective weak Hamiltonian that change isospin by Delta I=3/2.
Observation of the baryonic B decay B ¯ 0 ? ? c + ? ¯ K ?
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D. A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Dubrovin, M. S.; Huard, Z.; Meadows, B. T.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Munerato, M.; Negrini, M.; Piemontese, L.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Nicolaci, M.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Edwards, A. J.; Adametz, A.; Marks, J.; Uwer, U.; Bernlochner, F. U.; Ebert, M.; Lacker, H. M.; Lueck, T.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Schune, M. H.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Paramesvaran, S.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Prencipe, E.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Simi, G.; Dallapiccola, C.; Cowan, R.; Dujmic, D.; Sciolla, G.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Neri, N.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Honscheid, K.; Kass, R.; Brau, J.; Frey, R.; Sinev, N. B.; Strom, D.; Torrence, E.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Sitt, S.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Bünger, C.; Grünberg, O.; Hartmann, T.; Leddig, T.; Schröder, H.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Aston, D.; Bard, D. J.; Bartoldus, R.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Li, S.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; Ofte, I.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Santoro, V.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va’vra, J.; Wagner, A. P.; Weaver, M.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Yarritu, A. K.; Young, C. C.; Ziegler, V.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Benitez, J. F.; Burchat, P. R.; Miyashita, T. S.
2011-10-01T23:59:59.000Z
We report the observation of the baryonic B decay B¯¯¯0?¯¯¯0?¯¯¯K? with a significance larger than 7 standard deviations based on 471×106 BB¯¯¯ pairs collected with the BABAR detector at the PEP-II storage ring at SLAC. We measure the branching fraction for the decay B¯¯¯0??+c?¯¯¯K? to be (3.8±0.8stat±0.2sys±1.0?c)×10??. The uncertainties are statistical, systematic, and due to the uncertainty in the ?+c branching fraction. We find that the ?+cK? invariant-mass distribution shows an enhancement above 3.5 GeV/c².
Time-resolved fluorescence decay measurements for flowing particles
Deka, C.; Steinkamp, J.A.
1999-06-01T23:59:59.000Z
Time-resolved fluorescence decay measurements are disclosed for flowing particles. An apparatus and method for the measurement and analysis of fluorescence for individual cells and particles in flow are described, wherein the rapid measurement capabilities of flow cytometry and the robust measurement and analysis procedures of time-domain fluorescence lifetime spectroscopy are combined. A pulse-modulated CW laser is employed for excitation of the particles. The characteristics and the repetition rate of the excitation pulses can be readily adjusted to accommodate for fluorescence decays having a wide range of lifetimes. 12 figs.
Rare Decays And Exotic States With BaBar
Robertson, S.H.; /McGill U.
2006-08-28T23:59:59.000Z
Results from the BABAR experiment are presented for searches for several rare FCNC B and D meson decays, including the modes B{sup 0} {yields} {ell}{sup +}{ell}{sup -} and D{sup 0} {yields} {ell}{sup +}{ell}{sup -}, B {yields} ({rho},{omega}){gamma} and B{sup +} {yields} (K,{pi}){sup +}{nu}{bar {nu}}. Limits on lepton flavor violation in neutrino-less {tau} decays are also discussed. Finally, results of BABAR searches for the strange pentaquark states {Theta}{sup +}(1540), {Xi}{sup --}(1860) and {Xi}{sup 0}(1860) are summarized.
Observation of ?_{cJ} decays to ??¯¯¯????
Ablikim, M.; Achasov, M. N.; Ambrose, D. J.; An, F. F.; An, Q.; An, Z. H.; Bai, J. Z.; Ban, Y.; Becker, J.; Bennett, J. V.; Bertani, M.; Bian, J. M.; Boger, E.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; Ding, W. M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Fang, J.; Fang, S. S.; Fava, L.; Feldbauer, F.; Feng, C. Q.; Ferroli, R. B.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y. P.; Han, Y. L.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, G. M.; Huang, J. S.; Huang, X. T.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, X. B.; Ji, X. L.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Kuehn, W.; Lai, W.; Lange, J. S.; Li, C. H.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, K.; Li, Lei; Li, Q. J.; Li, S. L.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Liao, X. T.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, C. Y.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H.; Liu, H. B.; Liu, H. H.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K. Y.; Liu, Kai; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. H.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. Y.; Ma, Y.; Maas, F. E.; Maggiora, M.; Malik, Q. A.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Morales Morales, C.; Motzko, C.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nicholson, C.; Nikolaev, I. B.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Park, J. W.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Prencipe, E.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, X. S.; Qin, Y.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schaefer, B. D.; Schulze, J.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Toth, D.; Ullrich, M.; Varner, G. S.; Wang, B.; Wang, B. Q.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q.; Wang, Q. J.; Wang, S. G.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Weidenkaff, P.; Wen, Q. G.; Wen, S. P.; Werner, M.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, S. X.; Wu, W.; Wu, Z.; Xia, L. G.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, G. M.; Xu, H.; Xu, Q. J.; Xu, X. P.; Xu, Z. R.; Xue, F.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yu, S. P.; Yuan, C. Z.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, S. H.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. S.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, H. S.; Zhao, J. W.; Zhao, K. X.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zhong, B.; Zhong, J.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, X. W.; Zhu, Y. C.; Zhu, Y. M.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.
2012-09-01T23:59:59.000Z
Decays of the ?_{cJ} states (J=0, 1, 2) to ??¯¯¯????, including processes with intermediate ?(1385), are studied through the E1 transition ?'???_{cJ} using 106×10? ?' events collected with the BESIII detector at BEPCII. This is the first observation of ?cJ decays to the final state ??¯¯¯????. The branching ratio of the intermediate process ?_{cJ}??(1385)^{±}?¯¯¯(1385)^{?} is also measured for the first time, and the results agree with the theoretical predictions based on the color-octet effect.
Two-body D+s decays to ??+, ???+, ??+, ???+, and ??+
Ammar, Raymond G.; Baringer, Philip S.; Coppage, Don; Davis, Raymond Jr.; Kelly, M.; Kwak, Nowhan; Lam, H.; Ro, S.; Daoudi, M.; Ford, W. T.; Johnson, D. R.; Lingel, K.; Lohner, M.; Rankin, P.; Smith, J. G.
1992-06-01T23:59:59.000Z
I I 0) LLJ 5000 for which the branching ratios are 38.9% and 23.6%, re- spectively [2]. The yy invariant-mass distribution for momenta above 1.5 GeV/c is shown as the histogram in Fig. 2(a). We also require that the decay angle cosine be- tween both... of the y's and the yy direction in the labora- tory transformed into the yy rest frame be smaller than 0.8. There is considerable background, mostly from m decays. When we eliminate any photon which, with another photon, makes a mass combination...
Finite Time Vacuum Survival Amplitude and Vacuum Energy Decay
Enrique Álvarez; Roberto Vidal
2011-07-15T23:59:59.000Z
The problem of the vacuum energy decay is studied for both signs of the cosmological constant, through the analysis of the vacuum survival amplitude, defined in terms of the {\\em conformal time}, $z$, by ${\\mathcal A}(z,z^\\prime)\\equiv $. Transition amplitudes are computed for finite time-span, $Z\\equiv z^\\prime-z$, and their {\\em late time} behavior (directly related to the putative decay width of the state) as well as the transients are discussed up to first order in the coupling constant, $\\lambda$.
Heavy Sterile Neutrinos and Neutrinoless Double Beta Decay
P. Bamert; C. P. Burgess; R. N. Mohapatra
1994-10-12T23:59:59.000Z
We investigate the possibility of producing neutrinoless double beta decay without having an electron neutrino with a mass in the vicinity of 1 eV. We do so by having a much lighter electron neutrino mix with a much heavier (m > 1 GeV) sterile neutrino. We study the constraints on the masses and mixings of such heavy sterile neutrinos from existing laboratory, astrophysical and cosmological information, and discuss the properties it would require in order to produce a detectable signal in current searches for neutrinoless double beta decay.
Correlations of decay times of entangled composite unstable systems
Thomas Durt
2012-04-19T23:59:59.000Z
The role played by Time in the quantum theory is still mysterious by many aspects. In particular it is not clear today whether the distribution of decay times of unstable particles could be described by a Time Operator. As we shall discuss, different approaches to this problem (one could say interpretations) can be found in the literature on the subject. As we shall show, it is possible to conceive crucial experiments aimed at distinguishing the different approaches, by measuring with accuracy the statistical distribution of decay times of entangled particles. Such experiments can be realized in principle with entangled kaon pairs.
Particle Decay from Giant Resonance Region of Ca-40
Youngblood, David H.; Bacher, A. D.; Brown, D. R.; Bronson, J. D.; Moss, JM; Rozsa, C. M.
1977-01-01T23:59:59.000Z
, College Station, Texas 77843 (Received 12 July 1976) The reactions ' Ca(a, 2a)' Ar and Ca(a, ap)' K have been studied at 115-MeV bombarding energy in order to obtain the charged particle decay characteristics of the giant quadrupole resonance at E?= 18....0 MeV. Energy and angle were measured for both outgoing light particles to completely define the kinematics. Weak proton decay to the d?, (I ~ /I = 0.08+00,') and s?, (I p /I = 0.22+0'08) hole states of "K was observed from the giantP0 ' ?0.03 1...
A Search for Neutrinoless Tau Decays to Three Leptons
Kolb, Jeffrey A.; /Oregon U. /SLAC; ,
2008-09-24T23:59:59.000Z
Using approximately 350 million {tau}{sup +}{tau}{sup -} pair events recorded with the BaBar detector at the Stanford Linear Accelerator Center between 1999 and 2006, a search has been made for neutrinoless, lepton-flavor violating tau decays to three lighter leptons. All six decay modes consistent with conservation of electric charge and energy have been considered. With signal selection efficiencies of 5-12%, we obtain 90% confidence level upper limits on the branching fraction {Beta}({tau} {yields} {ell}{ell}{ell}) in the range (4-8) x 10{sup -8}.
New experimental limits on the alpha decays of lead isotopes
J. W. Beeman; F. Bellini; L. Cardani; N. Casali; S. Di Domizio; E. Fiorini; L. Gironi; S. S. Nagorny; S. Nisi; F. Orio; L. Pattavina; G. Pessina; G. Piperno; S. Pirro; E. Previtali; C. Rusconi; C. Tomei; M. Vignati
2012-12-12T23:59:59.000Z
For the first time a PbWO4 crystal was grown using ancient Roman lead and it was run as a cryogenic detector. Thanks to the simultaneous and independent read-out of heat and scintillation light, the detector was able to discriminate beta/gamma interactions with respect to alpha particles down to low energies. New more stringent limits on the alpha decays of the lead isotopes are presented. In particular a limit of T_{1/2} > 1.4*10^20 y at a 90% C.L. was evaluated for the alpha decay of 204Pb to 200Hg.
Non-leptonic decays of Charmed mesons into two Pseudoscalars
Aritra Biswas; Nita Sinha; Gauhar Abbas
2015-04-20T23:59:59.000Z
We examine the role of resonant coupled channel final state interactions (FSI), as well as weak annihilation and exchange contributions in explaining all the two body hadronic $D\\rightarrow PP$ decay modes data. In the un-unitarized amplitudes we include modified Wilson coefficients with non-factorizable corrections as parameters. For the hadronic form factors, the z-series expansion method is used to get the $q^2$ dependence. The FSI effects are incorporated via a phenomenological approach with widths of resonances to various channels taken from observations where available, and others as additional parameters to be determined from fits of all the theoretical rates to the measured ones. Our results for the rather hard to explain $D^0\\rightarrow K^+K^-, \\pi^+\\pi^- $ are in agreement with measured values. We demonstrate that both weak exchange as well as FSI effects are required to get the correct branching ratio for the $D^ \\rightarrow K^0\\bar{K^0}$ mode. Using our unitarized amplitudes we evaluate the strong phase difference between the amplitudes for $D^0\\rightarrow K^-\\pi^+$ and $D^0\\rightarrow K^+\\pi^-$ and find it to be in complete agreement with the recent BES III result.
Sun, Junfeng; Hu, Xiaohui; Yang, Yueling
2015-01-01T23:59:59.000Z
In this paper, we investigate the contributions of hard spectator scattering and annihilation in $B$ ${\\to}$ $PV$ decays within QCD factorization framework. With available experimental data on $B$ ${\\to}$ ${\\pi}K^{\\ast}$, ${\\rho}K$, ${\\pi}{\\rho}$ and $K{\\phi}$ decays, comprehensive $\\chi^2$ analyses on parameters $X_{A,H}^{i,f}$ or (${\\rho}_{A,H}^{i,f}$, ${\\phi}_{A,H}^{i,f}$) are performed, where $X_{A}^{f}$ ($X_{A}^{i}$) and $X_{H}$ are used to parameterize the endpoint divergences of the (non)factorizable annihilation and hard spectator scattering amplitudes, respectively. From $\\chi^2$ analyses, it is found that (1) the topology-dependent parameterization is feasible for $B$ ${\\to}$ $PV$ decays; (2) A relatively small value of inverse moment parameter ${\\lambda}_{B}$ ${\\sim}$ 0.2 GeV for $B$ meson wave function is allowed by $B$ ${\\to}$ $PP$, $PV$ decays; (3) At present accurate level of experimental measurements and theoretical evaluations, $X_{H}$ $=$ $X_{A}^{i}$ is a good simplification, but $X_{H}$ $\
Probing Spectator Scattering and Annihilation Corrections in $B_{s}$ $\\to$ $PV$ Decays
Chang, Qin; Sun, Junfeng; Yang, Yueling
2015-01-01T23:59:59.000Z
Motivated by the recent LHCb measurements on $\\bar{B}_{s}$ $\\to$ $\\pi^{-}K^{*+}$ and $\\bar{B}_{s}$ $\\to$ $K^{\\pm}K^{*\\mp}$ decay modes, we revisit the $B_{s}$ $\\to$ $PV$ decays within QCD factorization framework. The effects of hard-spectator scattering and annihilation corrections are studied in detail. After performing a $\\chi^2$-fit on the end-point parameters $X_A^{i,f}$ ($\\rho_A^{i,f}$, $\\phi_A^{i,f}$) and $X_H$ ($\\rho_H$, $\\phi_H$) with available data, it is found that although some possible mismatches exist, the universalities of $X_A^{i,f}$ and $X_H$ in $B_s$ and $B_{u,d}$ systems are still allowed within theoretical uncertainties and experimental errors. With the end-point parameters gotten from $B_{u,d}$ $\\to$ $PV$ decays, the numerical results and detailed analyses for the observables of $\\bar{B}_{s}$ ${\\to}$ $\\pi K^{\\ast}$, $\\rho K$, $\\pi\\rho$, $\\pi\\phi$ and $K\\phi$ decay modes are presented. In addition, we have identified a few useful observables, especially the ones of $\\bar{B}_{s}$ $\\to$ $\\pi^...
Measurement of branching fraction and first evidence of CP violation in B??a?±(1260)?? decays
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Dalseno, J.; Adachi, I.; Aihara, H.; Asner, D. M.; Aulchenko, V.; Aushev, T.; Bakich, A. M.; Bay, A.; Belous, K.; Bhuyan, B.; et al
2012-11-01T23:59:59.000Z
We present a measurement of the branching fraction and time-dependent CP violation parameters in B??a±?(1260)?? decays. The results are obtained from the final data sample containing 772×10? BB¯¯¯ pairs collected at the ?(4S) resonance with the Belle detector at the KEKB asymmetric-energy e?e? collider. We obtain the product branching fraction B(B??a±?(1260)??)×B(a±?(1260)??±???±)=(11.1±1.0(stat)±1.4(syst))×10?? and an upper limit on the product branching fraction for a possible decay with the same final state B(B??a±?(1320)??)×B(a±?(1320)??±???±)more »respectively. Simultaneously, we also extract the CP-conserving parameters ?C=+0.54±0.11(stat)±0.07(syst), ?S=–0.09±0.14(stat)±0.06(syst), which, respectively, describe a rate difference and strong phase difference between the decay channels where the a±? does not contain the spectator quark and those where it does. We find first evidence of mixing-induced CP violation in B??a±?(1260)?? decays with 3.1? significance. The rate where the a±? does not contain the spectator quark from the B meson is found to dominate the rate where it does at the 4.1? level. However, there is no evidence for either time- and flavor-integrated direct CP violation or flavor-dependent direct CP violation.« less
Disentangling the various Mechanisms of neutrinoless double beta decay to extract the neutrino mass
Vergados, J. D. [Physics Department, University of Ioannina, Ioannina, GR 451 10, Greece and Theory Division, CERN 1211, Geneva 23 (Greece)
2011-12-16T23:59:59.000Z
It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay. By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, given the observation of the 0{nu}{beta}{beta}-decay in three different nuclei, e.g. {sup 76}Ge, {sup 100}Mo and {sup 130}Te, and assuming just three active lepton number violating parameters, e.g. light and heavy neutrino mass mechanisms in left handed currents as well as R-parity breaking SUSY mechanism, one may determine all lepton violating parameters, provided that they are relatively real.
A measurement of the 2 neutrino double beta decay rate of 130Te in the CUORICINO experiment
Kogler, Laura Katherine
2011-01-01T23:59:59.000Z
1.2.2 Neutrinoless double beta decay . . . . . 1.2.3 NuclearEvidence for Neutrinoless Double Beta Decay, Mod. Phys.on ’Evidence for Neutrinoless Double Beta Decay’, Mod. Phys.
A measurement of the 2 neutrino double beta decay rate of Te-130 in the CUORICINO experiment
Kogler, Laura
2012-01-01T23:59:59.000Z
1.2.2 Neutrinoless double beta decay . . . . . 1.2.3 NuclearEvidence for Neutrinoless Double Beta Decay, Mod. Phys.on ’Evidence for Neutrinoless Double Beta Decay’, Mod. Phys.
Neutrinoless Double Beta Decay and {nu}-Mass Determination
Pedretti, M. [Universita dell Insubria, Via Vallegio 11, 22100 Como (Italy)
2005-10-12T23:59:59.000Z
The search for Neutrinoless Double Beta Decay could improve our knowledge on neutrino properties. After a brief discussion on the implications of the observation of this rare process, I will introduce the experimental approaches and review the prospects of the search for this nuclear transition.
Neutrinoless double beta decay mediated by the neutrino magnetic moment
Gó?d?, Marek
2014-01-01T23:59:59.000Z
We present a new channel of the neutrinoless double beta decay. In this scenario neutrinos not only oscillate inside the nucleus but also interact with an external non-uniform magnetic field. We assume that the field rotates about the direction of motion of the neutrino and show, that for a certain speed of rotation the half-life of the $0\
Conditions for detecting CP violation via neutrinoless double beta decay
Alicja Joniec; Marek Zralek
2005-12-30T23:59:59.000Z
Neutrinoless double beta decay data together with information on the absolute neutrino masses obtained from the future KATRIN experiment and/or astrophysical measurements give a chance to find CP violation in the lepton sector with Majorana neutrinos. We derive and discuss necessary conditions which make discovery of such CP violation possible for the future neutrino oscillation and mass measurements data.
Neutrinoless double beta decay mediated by the neutrino magnetic moment
Marek Gó?d?; Wies?aw A. Kami?ski
2014-11-07T23:59:59.000Z
We present a new channel of the neutrinoless double beta decay. In this scenario neutrinos not only oscillate inside the nucleus but also interact with an external non-uniform magnetic field. We assume that the field rotates about the direction of motion of the neutrino and show, that for a certain speed of rotation the half-life of the $0\
MAJORANA Neutrinoless Double-Beta Decay DUSEL R&D
Wilkerson, John F.
2009-09-04T23:59:59.000Z
The Majorana research and development is addressing key issues and risks related to the collaboration's goal of undertaking a search for neutrinoless double-beta decay (0{nu}{beta}{beta}) in {sup 76}Ge using an array of hyper-pure Ge-diodes (HPGe). The observation of this decay would provide critical insight into our understanding of neutrinos, yielding definitive evidence that neutrinos are Majorana particles and providing information on the absolute mass of neutrinos. Achieving sensitivities to 0{nu}{beta}{beta} decay half-lives on the order of 10{sup 26} years requires ultra-low backgrounds in the 2039 keV region where a 0{nu}{beta}{beta} decay peak would be observed. The goal of our R&D program has been to demonstrate the feasibility of all components of Majorana and to provide an integrated evaluation framework, allowing for optimization of these components in terms of background, background suppression, and signal detection efficiency and acceptance. This report covers work carried out by Majorana collaboration members at the University of Washington as part of the overall Majorana collaboration activities. Specifically the Majorana group at the University of Washington was involved in moving forward on demonstrating technology for clean large-scale cryostats and mounting the HPGe crystals in low-mass holders. The UW activities included assistance in the procurement and assembly of an electroforming system for large size cryostats, and design and fabrication of prototype crystal mounting hardware.
Conditions for detecting CP violation via neutrinoless double beta decay
Joniec, A.; Zralek, M. [Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland)
2006-02-01T23:59:59.000Z
Neutrinoless double beta decay data, together with information on the absolute neutrino masses obtained from the future KATRIN experiment and/or astrophysical measurements, provide a chance to find CP violation in the lepton sector with Majorana neutrinos. We derive and discuss necessary conditions which make discovery of such CP violation possible for the future neutrino oscillation and mass measurements data.
New Advances in Neutrinoless Double Beta Decay Matrix Elements
Munoz, Jose Barea [Instituto de Estructura de la Materia, C.S.I.C. Unidad Asociada al Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Fisica, Universidad de Sevilla, Apartado 1065, 41080 Sevilla (Spain)
2010-08-04T23:59:59.000Z
We present the matrix elements necessary to evaluate the half-life of some neutrinoless double beta decay candidates in the framework of the microscopic interacting boson model (IBM). We compare our results with those from other models and extract some simple features of the calculations.
Neutrinoless double beta decay in the microscopic interacting boson model
Iachello, F. [Center for Theoretical Physics, Sloane Physics Laboratory Yale University New Haven, CT 06520-8120 (United States)
2009-11-09T23:59:59.000Z
The results of a calculation of the nuclear matrix elements for neutrinoless double beta decay in the closure approximation in several nuclei within the framework of the microscopic interacting boson model (IBM-2) are presented and compared with those calculated in the shell model (SM) and quasiparticle random phase approximation (QRPA)
Charmed and light pseudoscalar meson decay constants from HISQ simulations
A. Bazavov; C. Bernard; C. Bouchard; C. DeTar; D. Du; A. X. El-Khadra; J. Foley; E. D. Freeland; E. Gámiz; Steven Gottlieb; U. M. Heller; J. Kim; J. Komijani; A. S. Kronfeld; J. Laiho; L. Levkova; P. B. Mackenzie; E. T. Neil; J. N. Simone; R. L. Sugar; D. Toussaint; R. S. Van de Water; R. Zhou
2014-11-10T23:59:59.000Z
We compute the leptonic decay constants $f_{D^+}$, $f_{D_s}$, and $f_{K^+}$, and the quark-mass ratios $m_c/m_s$ and $m_s/m_l$ in unquenched lattice QCD. We use the MILC highly improved staggered quark (HISQ) ensembles with four dynamical quark flavors. Our primary results are $f_{D^+} = 212.6(0.4)({}^{+1.0}_{-1.2})\\ \\mathrm{MeV}$, $f_{D_s} = 249.0(0.3)({}^{+1.1}_{-1.5})\\ \\mathrm{MeV}$, and $f_{D_s}/f_{D^+} = 1.1712(10)({}^{+29}_{-32})$, where the errors are statistical and total systematic, respectively. We also obtain $f_{K^+}/f_{\\pi^+} = 1.1956(10)({}^{+26}_{-18})$, updating our previous result, and determine the quark-mass ratios $m_s/m_l = 27.35(5)({}^{+10}_{-7})$ and $m_c/m_s = 11.747(19)({}^{+59}_{-43})$. When combined with experimental measurements of the decay rates, our results lead to precise determinations of the CKM matrix elements $|V_{us}| = 0.22487(51) (29)(20)(5)$, $|V_{cd}|=0.217(1) (5)(1)$ and $|V_{cs}|= 1.010(5)(18)(6)$, where the errors are from this calculation of the decay constants, the uncertainty in the experimental decay rates, structure-dependent electromagnetic corrections, and, in the case of $|V_{us}|$, the uncertainty in $|V_{ud}|$, respectively.
Particle production related to the tunneling in false vacuum decay
Michael Maziashvili
2003-02-15T23:59:59.000Z
Motivated by the work of Mersini, the particle production related to the tunneling in false vacuum decay is carefully investigated in the thin-wall approximation. It is shown that in this case the particle production is exponentially suppressed even when the momentum is comparable to the curvature scale of the bubble. The number of created particles is ultraviolet finite.
Search for dinucleon decay into pions at Super-Kamiokande
J. Gustafson; K. Abe; Y. Haga; Y. Hayato; M. Ikeda; K. Iyogi; J. Kameda; Y. Kishimoto; M. Miura; S. Moriyama; M. Nakahata; T. Nakajima; Y. Nakano; S. Nakayama; A. Orii; H. Sekiya; M. Shiozawa; A. Takeda; H. Tanaka; T. Tomura; R. A. Wendell; T. Irvine; T. Kajita; I. Kametani; K. Kaneyuki; Y. Nishimura; E. Richard; K. Okumura; L. Labarga; P. Fernandez; S. Berkman; H. A. Tanaka; S. Tobayama; E. Kearns; J. L. Raaf; J. L. Stone; L. R. Sulak; M. Goldhaber; G. Carminati; W. R. Kropp; S. Mine; P. Weatherly; A. Renshaw; M. B. Smy; H. W. Sobel; V. Takhistov; K. S. Ganezer; B. L. Hartfiel; J. Hill; N. Hong; J. Y. Kim; I. T. Lim; T. Akiri; A. Himmel; K. Scholberg; C. W. Walter; T. Wongjirad; T. Ishizuka; S. Tasaka; J. S. Jang; J. G. Learned; S. Matsuno; S. N. Smith; T. Hasegawa; T. Ishida; T. Ishii; T. Kobayashi; T. Nakadaira; K. Nakamura; Y. Oyama; K. Sakashita; T. Sekiguchi; T. TsukamotoA. T. Suzuki; Y. Takeuchi; T. Yano; S. Hirota; K. Huang; K. Ieki; T. Kikawa; A. Minamino; T. Nakaya; K. Suzuki; S. Takahashi; Y. Fukuda; K. Choi; Y. Itow; G. Mitsuka; T. Suzuki; P. Mijakowski; J. Hignight; J. Imber; C. K. Jung; J. L. Palomino; C. Yanagisawa; H. Ishino; T. Kayano; A. Kibayashi; Y. Koshio; T. Mori; M. Sakuda; Y. Kuno; R. Tacik; S. B. Kim; H. Okazawa; Y. Choi; K. Nishijima; M. Koshiba; Y. Suda; Y. Totsuka; M. Yokoyama; C. Bronner; K. Martens; Ll. Marti; Y. Suzuki; M. R. Vagins; J. F. Martin; P. de Perio; A. Konaka; M. J. Wilking; S. Chen; Y. Zhang; R. J. Wilkes
2015-04-04T23:59:59.000Z
A search for dinucleon decay into pions with the Super-Kamiokande detector has been performed with an exposure of 282.1 kiloton-years. Dinucleon decay is a process that violates baryon number by two units. We present the first search for dinucleon decay to pions in a large water Cherenkov detector. The modes $^{16}$O$(pp) \\rightarrow$ $^{14}$C$\\pi^{+}\\pi^{+}$, $^{16}$O$(pn) \\rightarrow$ $^{14}$N$\\pi^{+}\\pi^{0}$, and $^{16}$O$(nn) \\rightarrow$ $^{14}$O$\\pi^{0}\\pi^{0}$ are investigated. No significant excess in the Super-Kamiokande data has been found, so a lower limit on the lifetime of the process per oxygen nucleus is determined. These limits are: $\\tau_{pp\\rightarrow\\pi^{+}\\pi^{+}} > 7.22 \\times 10^{31}$ years, $\\tau_{pn\\rightarrow\\pi^{+}\\pi^{0}} > 1.70 \\times 10^{32}$ years, and $\\tau_{nn\\rightarrow\\pi^{0}\\pi^{0}} > 4.04 \\times 10^{32}$ years. The lower limits on each mode are about two orders of magnitude better than previous limits from searches for dinucleon decay in iron.
Search for dinucleon decay into pions at Super-Kamiokande
Gustafson, J; Haga, Y; Hayato, Y; Ikeda, M; Iyogi, K; Kameda, J; Kishimoto, Y; Miura, M; Moriyama, S; Nakahata, M; Nakajima, T; Nakano, Y; Nakayama, S; Orii, A; Sekiya, H; Shiozawa, M; Takeda, A; Tanaka, H; Tomura, T; Wendell, R A; Irvine, T; Kajita, T; Kametani, I; Kaneyuki, K; Nishimura, Y; Richard, E; Okumura, K; Labarga, L; Fernandez, P; Berkman, S; Tanaka, H A; Tobayama, S; Kearns, E; Raaf, J L; Stone, J L; Sulak, L R; Goldhaber, M; Carminati, G; Kropp, W R; Mine, S; Weatherly, P; Renshaw, A; Smy, M B; Sobel, H W; Takhistov, V; Ganezer, K S; Hartfiel, B L; Hill, J; Hong, N; Kim, J Y; Lim, I T; Akiri, T; Himmel, A; Scholberg, K; Walter, C W; Wongjirad, T; Ishizuka, T; Tasaka, S; Jang, J S; Learned, J G; Matsuno, S; Smith, S N; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Suzuki, T TsukamotoA T; Takeuchi, Y; Yano, T; Hirota, S; Huang, K; Ieki, K; Kikawa, T; Minamino, A; Nakaya, T; Suzuki, K; Takahashi, S; Fukuda, Y; Choi, K; Itow, Y; Mitsuka, G; Suzuki, T; Mijakowski, P; Hignight, J; Imber, J; Jung, C K; Palomino, J L; Yanagisawa, C; Ishino, H; Kayano, T; Kibayashi, A; Koshio, Y; Mori, T; Sakuda, M; Kuno, Y; Tacik, R; Kim, S B; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Suda, Y; Totsuka, Y; Yokoyama, M; Bronner, C; Martens, K; Marti, Ll; Suzuki, Y; Vagins, M R; Martin, J F; de Perio, P; Konaka, A; Wilking, M J; Chen, S; Zhang, Y; Wilkes, R J
2015-01-01T23:59:59.000Z
A search for dinucleon decay into pions with the Super-Kamiokande detector has been performed with an exposure of 282.1 kiloton-years. Dinucleon decay is a process that violates baryon number by two units. We present the first search for dinucleon decay to pions in a large water Cherenkov detector. The modes $^{16}$O$(pp) \\rightarrow$ $^{14}$C$\\pi^{+}\\pi^{+}$, $^{16}$O$(pn) \\rightarrow$ $^{14}$N$\\pi^{+}\\pi^{0}$, and $^{16}$O$(nn) \\rightarrow$ $^{14}$O$\\pi^{0}\\pi^{0}$ are investigated. No significant excess in the Super-Kamiokande data has been found, so a lower limit on the lifetime of the process per oxygen nucleus is determined. These limits are: $\\tau_{pp\\rightarrow\\pi^{+}\\pi^{+}} > 7.22 \\times 10^{31}$ years, $\\tau_{pn\\rightarrow\\pi^{+}\\pi^{0}} > 1.70 \\times 10^{32}$ years, and $\\tau_{nn\\rightarrow\\pi^{0}\\pi^{0}} > 4.04 \\times 10^{32}$ years. The lower limits on each mode are about two orders of magnitude better than previous limits from searches for dinucleon decay in iron.
Hadronic decays of the tau lepton: Theoretical outlook
J. Portoles
2007-02-18T23:59:59.000Z
The structure of the form factors stemmed from the hadronization of QCD currents in the energy region of the resonances can be explored through the analyses of exclusive hadronic decays of the tau lepton. I give a short review on the later theoretical progress achieved in the description of experimental data.
Fast Neutrino Decay in the Minimal Seesaw Model
Anjans S. Joshipura; Saurabh D. Rindani
1992-05-13T23:59:59.000Z
Neutrino decay in the minimal seesaw model containing three right handed neutrinos and a complex $SU(2)\\times U(1)$ singlet Higgs in addition to the standard model fields is considered. A global horizontal symmetry $U(1)_H$ is imposed, which on spontaneous breaking gives rise to a Goldstone boson. This symmetry is chosen in a way that makes a) the contribution of heavy ($\\leq$ MeV) majorana neutrinos to the neutrinoless double beta decay amplitude vanish and b) allows the heavy neutrino to decay to a lighter neutrino and the Goldstone boson. It is shown that this decay can occur at a rate much faster than in the original Majoron model even if one does not introduce any additional Higgs fields as is done in the literature. Possibility of describing the 17 keV neutrino in this minimal seesaw model is investigated. While most of the cosmological and astrophysical constraints on the 17 keV neutrino can be satisfied in this model, the laboratory limits coming from the neutrino oscillations cannot be easily met. An extension which removes this inadequacy and offers a consistent description of the 17 keV neutrino is discussed.
Simple model for decay of laser generated shock waves
Trainor, R.J.
1980-10-24T23:59:59.000Z
A simple model is derived to calculate the hydrodynamic decay of laser-generated shock waves. Comparison with detailed hydrocode simulations shows good agreement between calculated time evolution of shock pressure, position, and instantaneous pressure profile. Reliability of the model decreases in regions of the target where superthermal-electron preheat effects become comparable to shock effects.
Search for charged Higgs bosons in top quark decays
Baringer, Philip S.; Bean, Alice; Clutter, Justace Randall; Moulik, Tania; Wilson, Graham Wallace; DØ Collaboration; Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahsan, M.
2009-12-07T23:59:59.000Z
We present a search for charged Higgs bosons in top quark decays. We analyze the e+jetse+jets, ?+jets?+jets, ee, e?, ??, ?e and ?? final states from top quark pair production events, using data from about 1 fb^(?1) of integrated luminosity recorded...
Forbidden unique beta-decays and neutrino mass
Dvornický, Rastislav [Bogoliubov Laboratory of Theoretical Physics, JINR Dubna, 141980 Dubna, Moscow region, Russian Federation and Department of Nuclear Physics and Biophysics, Comenius University, Mlynská dolina F1, SK-84215 Bratislava (Slovakia); Šimkovic, Fedor [Department of Nuclear Physics and Biophysics, Comenius University, Mlynská dolina F1, SK-84215 Bratislava, Slovakia and IEAP, Czech Technical University, CZ-128 00 Prague (Czech Republic)
2013-12-30T23:59:59.000Z
The measurement of the electron spectrum in beta-decays provides a robust direct determination of the values of neutrino masses. The planned rhenium beta-decay experiment, called the “Microcalorimeter Arrays for a Rhenium Experiment” (MARE), might probe the absolute mass scale of neutrinos with the same sensitivity as the Karlsruhe tritium neutrino mass (KATRIN) experiment, which is expected to collect data in a near future. In this contribution we discuss the spectrum of emitted electrons close to the end point in the case of the first unique forbidden beta-decay of {sup 79}Se, {sup 107}Pd and {sup 187}Re. It is found that the p{sub 3/2}-wave emission dominates over the s{sub 1/2}-wave. It is shown that the Kurie plot near the end point is within a good accuracy linear in the limit of massless neutrinos like the Kurie plot of the superallowed beta-decay of {sup 3}H.
Symmetry relations in charmless B->PPP decays
Gronau, M; Gronau, Michael; Rosner, Jonathan L.
2005-01-01T23:59:59.000Z
Strangeness-changing decays of $B$ mesons to three-body final states of pions and kaons are studied under the assumption that they are dominated by a $\\Delta I=0$ penguin amplitude with flavor structure $\\bar b \\to \\bar s$. Several isospin relations for $B\\to K\\pi\\pi$ and for underlying quasi-two-body decays are compared successfully with experiment. A seeming anomaly comparing $B^+\\to K^*_0(1430)^0\\pi^+$ and $B^0\\to K^*_0(1430)^+ \\pi^-$ is resolved by using an ambiguity in fitting the Dalitz plot of the former process, demonstrating the importance of comparing isospin-related Dalitz plots. Relations for B decays into three kaons are derived in terms of final states involving $K_S$ or $K_L$, assuming that $\\phi K$-subtracted decay amplitudes are symmetric in $K$ and $\\bar K$, as has been observed experimentally. Rates due to nonresonant backgrounds are studied using a simple universal model, which may reduce discrete ambiguities in Dalitz plot analyses.
Observation of B(0) decay to 2 charmless mesons
Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kwak, Nowhan; Lam, H.
1993-12-01T23:59:59.000Z
We report results from a search for the decays B0 --> pi+pi-, B0 --> K+pi-, and B0 --> K+K-. We find 90% confidence level upper limits on the branching fractions, B(pipi) < 2.9 x 10(-5) , B(Kpi) < 2.6 x 10(-5), and B(KK) ...
Analysis of hadronic transitions in ?(3S) decays
Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kwak, Nowhan; Lam, H.
1994-01-01T23:59:59.000Z
Using the CLEO II detector, we have measured the branching fractions for ?(3S)????(1S), ?(3S)????(2S), and the cascade ?(3S)??(2S)+X, ?(2S)??+???(1S), analyzing the exclusive mode where the daughter ? state decays to a ...
TIME-DECAYING SKETCHES FOR ROBUST AGGREGATION OF SENSOR DATA
Cormode, Graham
, AND BOJIAN XU§ Abstract. We present a new sketch for summarizing network data. The sketch has the follow- ing, such as sensor networks: the sketch is duplicate-insensitive, i.e. re-insertions of the same data will not affect. sensor network, data streams, time decay, asynchrony, data aggregation, duplicates AMS subject
Neutrinoless Double Beta Decay with R-parity Violation
Yosuke Uehara
2002-06-26T23:59:59.000Z
We consider recently observed neutrinoless double beta decay in the context of the minimal supersymmetric standard model with R-parity violating couplings lambda^{'}. We observe that most of the current experimental bounds on the R-parity violating couplings do not exclude the possibility that the neutrinoless double beta decay is caused by R-parity violation. But if we consider K-bar{K} oscillation, we observe that we have to make the R-parity violating couplings generation-dependent to accomodate with the observed neutrinoless double beta decay. And furthermore, we need some mechanism to cancel the contribution to K-bar{K} mixing from a large R-parity violating coupling. We realized this cancellation by assuming that the first- and the second- generation of quark sector do not couple with the first-generation lepton sector by R-parity violating couplings except the term W=lambda_{111}^{'} L_{1} Q_{1} D_{1}^{c}, which is responsible for the observed neutrinoless double beta decay.
DS+ DECAYS TO ETA-PI+ AND ETA'PI+
Ammar, Raymond G.; Baringer, Philip S.; Coppage, Don; Davis, Robin E. P.; Kelly, M.; Kwak, Nowhan; Lam, H.; Ro, S.
1992-03-01T23:59:59.000Z
Using the CLEO II detector, we have accurately measured D(s) decay branching ratios relative to the phi-pi+ mode for the eta-pi+ and eta'pi+ states, for which there are conflicting claims; our results are 0.54 +/- 0.09 +/- 0.06 and 1.20 +/- 0...
Decay Oscillations in Electron Capture and the Neutrino Mass Difference
Murray Peshkin
2014-03-17T23:59:59.000Z
Quantum mechanical theory disallows the model that has been used to infer the neutrino mass difference from the reported "GSI oscillations" in the rates of decay of hydrogen-like ions by electron capture. It has not been proved that the existence of mass-difference-dependent oscillations conflicts with quantum mechanics but no consistent quantum mechanical model has been shown to predict them.
Observation of the Decay B- --> Ds(*) K- l- nubar
del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, David Nathan; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U.; /more authors..
2011-08-12T23:59:59.000Z
We report the observation of the decay B{sup -} {yields} D{sub s}{sup (*)+} K{sup -}{ell}{sup -}{bar {nu}}{sub {ell}} based on 342 fb{sup -1} of data collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} storage rings at SLAC. A simultaneous fit to three D{sub s}{sup +} decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay B{sup -} {yields} D{sub s}{sup (*)+} K{sup -}{ell}{sup -}{bar {nu}}{sub {ell}} with a significance greater than five standard deviations (including systematic uncertainties) and measure its branching fraction to be {Beta}(B{sup -} {yields} D{sub s}{sup (*)+} K{sup -}{ell}{sup -}{bar {nu}}{sub {ell}}) = [6.13{sub -1.03}{sup +1.04}(stat.) {+-} 0.43(syst.) {+-} 0.51({Beta}(D{sub s}))] x 10{sup -4}, where the last error reflects the limited knowledge of the D{sub s} branching fractions.
Branching ratios for the beta decay of Na-21
Iacob, V. E.; Hardy, John C.; Gagliardi, Carl A.; Goodwin, J.; Nica, N.; Park, H. I.; Tabacaru, G.; Trache, L.; Tribble, Robert E.; Zhai, Y.; Towner, I. S.
2006-01-01T23:59:59.000Z
We have measured the beta-decay branching ratio for the transition from Na-21 to the first excited state of Ne-21. A recently published test of the standard model, which was based on a measurement of the beta-nu correlation ...
Semiclassical calculation of an induced decay of false vacuum
A. Monin; M. B. Voloshin
2010-04-12T23:59:59.000Z
We consider a model where a scalar field develops a metastable vacuum state and weakly interacts with another scalar field. In this situation we find the probability of decay of the false vacuum stimulated by the presence and collisions of particles of the second field. The discussed calculation is an illustration of the recently suggested thermal approach to treatment of induced semiclassical processes.
Effects of New Gravitational Interactions on Neutrinoless Double Beta Decay
H. V. Klapdor--Kleingrothaus; H. Päs; U. Sarkar
2000-04-13T23:59:59.000Z
It has recently been proposed that violations of Lorentz invariance or violations of the equivalence principle can be constrained from the non-observation of neutrinoless double beta decay. We generalize this analysis to all possible new gravitational interactions and discuss briefly the constraints for different cases.
Support of Evidence for Neutrinoless Double Beta Decay
H. V. Klapdor-Kleingrothaus; A. Dietz; I. V. Krivosheina; Ch. Doerr; C. Tomei
2003-12-12T23:59:59.000Z
Indirect support for the evidence of neutrinoless double beta decay reported recently, is obtained by analysis of other Ge double beta experiments, which yield independent information on the background in the region of Q_(beta-beta). Some statistical features as well as background simulations with GEANT 4 of the HEIDELBERG-MOSCOW experiment are discussed which disprove recent criticism.
Search for rare top-quark decays at the LHC
Veloso, Filipe; The ATLAS collaboration
2015-01-01T23:59:59.000Z
Flavour-changing neutral-current (FCNC) top quark decays are suppressed by the GIM mechanism, but are enhanced by BSM models. Any evidence for top-quark FCNC decays could be an evidence for new physics. Searches for the FCNC decays $t\\to qX$ where $X=Z,\\gamma,H,g$ and $q=u,c$ performed by the ATLAS and CMS Collaborations are presented. Data collected during 2011 and 2012 from proton-proton ($pp$) collisions at the LHC at a centre-of-mass energy of $\\sqrt{s}=7$ and 8 TeV, corresponding to integrated luminosities ranging from 2.1 fb$^{-1}$ to 25 fb$^{-1}$, are analysed. Top-quark pair-production events with one top quark decaying through the $t\\to qZ,q\\gamma,qH$ channels and the other through the dominant Standard Model mode $t\\to bW$ are considered as signal, as well as direct top production for the $t\\to qg$ channel. No evidence for FCNC signals are found and upper limits on the $t\\to qX$ branching ratios are set at 95\\% confidence level.
Tau decays into three charged leptons and two neutrinos
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan
1996-04-01T23:59:59.000Z
We search for the radiative leptonic tau decays tau --> ee(+) e(-)nu(tau)nu(e) and tau --> mu e(+)e(-)nu(tau)nu(mu) using 3.60 fb(-1) of data collected by the CLEO-II experiment at the Cornell Electron Storage Ring. We present a first observation...
Observation of the radiative decay D*+-> D+gamma
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Zhou, L.
1998-05-01T23:59:59.000Z
We have observed a signal for the decay D*(+) --> D(+)gamma at a significance of 4 standard deviations. From the measured branching ratio B(D*(+) --> D(+)gamma)/B(D*(+) --> D(+)pi(0)) = 0.055 +/- 0.014 +/- 0.010 we find B(D*(+) --> D(+)gamma) = 0...
Consistent scenario for B{yields}PS decays
Delepine, D.; Lucio M, J. L.; Mendoza S, J. A.; Ramirez, Carlos A. [Instituto de Fisica, Universidad de Guanajuato Loma del Bosque 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Depto. de Fisica-Matematicas, Universidad de Pamplona Pamplona, Norte de Santander (Colombia); Escuela de Fisica, Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia)
2008-12-01T23:59:59.000Z
We consider B{yields}PS decays where P stands for pseudoscalar and S for a heavy (1500 MeV) scalar meson. We achieve agreement with available experimental data, which includes two orders of magnitude hierarchy, assuming the scalars mesons are two quark states. The contribution of the dipolar penguin operator O{sub 11} is quantified.
Estimation of the alpha decay half-lives D. N. Poenaru and M. Ivascu
Paris-Sud XI, Université de
semiempirical relationship is derived on the grounds of the fission theory of alpha decay. It takes }, based on the fission theory of alpha decay [16] have been derived and was briefly presented in refe
Has been Neutrinoless Double Beta Decay of 130Te observed by the CUORE experiment?
I. V. Kirpichnikov
2015-09-02T23:59:59.000Z
A recent reconsideration of a theoretical process of a neutrinoless double beta decay points out that a signal of the decay should be shifted by a few keV from the Q-value for the 2{\\ss}0{\
Has been Neutrinoless Double Beta Decay of 130Te observed by the CUORE experiment?
I. V. Kirpichnikov
2015-09-14T23:59:59.000Z
A recent reconsideration of a theoretical process of a neutrinoless double beta decay points out that a signal of the decay should be shifted by a few keV from the Q-value for the 2{\\ss}0{\
Has been Neutrinoless Double Beta Decay of 130Te observed by the CUORE experiment?
,
2015-01-01T23:59:59.000Z
A recent reconsideration of a theoretical process of a neutrinoless double beta decay points out that a signal of the decay should be shifted by a few keV from the Q-value for the 2{\\ss}0{\
Research paper Os decay system applied to dating platinum-group element
Reiners, Peter W.
Dating Geochronology Bushveld PGM We evaluate the 190 Pt186 Os decay system, measured by laser ablation. The 190 Pt186 Os decay system, measured by laser ablation-multi- collector-inductively coupled plasma
The MAJORANA DEMONSTRATOR A search for neutrinoless double-beta decay of germanium-76
MAJORANA The MAJORANA DEMONSTRATOR A search for neutrinoless double-beta decay of germanium-76 DEMONSTRATOR PANIC11 Neutrinoless double-beta decay (0) · Observation indicates: · Neutrino is a Majorana
Study of B Meson Decays to ppbarh Final States
Hryn'ova, Tetiana B.; /SLAC
2006-03-22T23:59:59.000Z
B mesons are unique among well-established non-quarkonium mesons in their ability to decay into baryons. Baryonic B decays offer a wide range of interesting areas of study: they can be used to test our theoretical understanding of rare decay processes involving baryons, search for direct CP violation and study low-energy QCD. This thesis presents measurements of branching fractions and a study of the decay dynamics of the charmless three-body decays of B meson into p{bar p}h final states, where h = {pi}{sup +}, K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}. With a sample of 232 million {Upsilon}(4S) {yields} B{bar B} events collected with the BaBar detector, we report the first observation of the B {yields} p{bar p}K*{sup 0} decay, and provide improved measurements of branching fractions of the other modes. The distribution of the three final-state particles is of particular interest since it provides dynamical information on the possible presence of exotic intermediate states such as the hypothetical pentaquark states {Theta}*{sup ++} and {Theta}{sup +}in the m{sub pK{sup +}} and m{sub pK{sub S}{sup 0}} spectra, respectively, or glueball states (such as the tensor glueball f{sub J}(2220)) in the m{sub p{bar p}} spectrum. No evidence for exotic states is found and upper limits on the branching fractions are set. An enhancement at low p{bar p} mass is observed in all the B {yields} p{bar p}h modes, and its shape is compared between the decay modes and with the shape of the time-like proton form factor. A Dalitz plot asymmetry in B {yields} p{bar p}K{sup +} mode suggests dominance of the penguin amplitude in this decay and disfavors the possibility that the low mass p{bar p} enhancement originates from the presence of a resonance below threshold (such as the recently seen baryonium candidate at 1835 MeV/c{sup 2}). We also identify decays of the type B {yields} X{sub c{bar c}}h {yields} p{bar p}h, where h = K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}, and X{sub c{bar c}} = {eta}{sub c} or J/{psi}. In particular, we report on the evidence of the B {yields} {eta}{sub c}K*{sup +} decay and provide a measurement of the width of {eta}{sub c}.
Beta-decay measurements of neutron-deficient cesium isotopes
Parry, R.F.
1983-03-01T23:59:59.000Z
Beta decay endpoint energy measurements of the neutron deficient cesium isotopes were done using an energy spectrum shape fitting technique. This was a departure from the typical method of endpoint energy analysis, the Fermi-Kurie plot. A discussion of the shape fitting procedure and its improved features are discussed. These beta endpoint measurements have led to total decay energies (Q/sub EC/) of the neutron deficient /sup 119/ /sup 123/Cs isotopes. The total decay energies of /sup 122m/Cs (Q/sub EC/ = 6.95 +- 0.25 MeV) and /sup 119/Cs (Q/sub EC/ = 6.26 +- 0.29 MeV) were new measurements. The total decay energies of /sup 123/Cs (Q/sub EC/ = 4.05 +- 0.18 MeV), /sup 122g/Cs (Q/sub EC/ = 7.05 +- 0.18 MeV), /sup 121/Cs (Q/sub EC/ = 5.21 +- 0.22 MeV), and /sup 120/Cs (Q/sub EC/ = 7.38 +- 0.23 MeV) were measurements with significantly improved uncertainties as compared to the literature. Further, a combination of the energy levels derived from previous literature gamma-gamma coincident measurements and the experimental beta-coincident gamma decay energies has supported an improved level scheme for /sup 121/Xe and the proposal of three new energy levels in /sup 119/Xe. Comparison of the experimental cesium mass excesses (determined with our Q/sub EC/ values and known xenon mass excesses) with both the literature and theoretical predicted values showed general agreement except for /sup 120/Cs. Possible explanations for this deviation are discussed.
Heretics of the False Vacuum: Gravitational Effects On and Of Vacuum Decay 2
T. Banks
2003-01-08T23:59:59.000Z
This paper reexamines the question of vacuum decay in theories of quantum gravity. In particular it suggests that decay into stable flat or AdS vacua, never occurs. Instead, vacuum decay occurs, if at all, into a cosmological spacetime. If the latter has negative cosmological constant, it undergoes a Big Crunch, which suggests that the whole picture is inconsistent. The question of decay of de Sitter space must be very carefully defined.
Search for invisible decays of the Higgs Boson at the LHC
White, Andrew; The ATLAS collaboration
2015-01-01T23:59:59.000Z
The latest from ATLAS and CMS on the search for invisible decays of the Higgs Boson will be presented.
Search for the Standard Model Higgs boson in the fully leptonic WW decay channel at CMS
LeBourgeois, Matthew; LeBourgeois, Matthew
2012-01-01T23:59:59.000Z
of the Higgs boson . . . . . . . . . . . . . . . . . . . . .the Higgs boson . . . . . . . . . . . . . . . . . . . . . .5 Search for the Higgs Boson in the WW Decay Channel . . .
Junfeng Sun; Qin Chang; Xiaohui Hu; Yueling Yang
2015-03-11T23:59:59.000Z
In this paper, we investigate the contributions of hard spectator scattering and annihilation in $B\\to PV$ decays within the QCD factorization framework. With available experimental data on $B\\to \\pi K^{\\ast}$, $\\rho K$, $\\pi \\rho$ and $K\\phi$ decays, comprehensive $\\chi^2$ analyses of the parameters $X_{A,H}^{i,f}({\\rho}_{A,H}^{i,f},{\\phi}_{A,H}^{i,f})$ are performed, where $X_A^f$ ($X_A^i$) and $X_H$ are used to parameterize the endpoint divergences of the (non)factorizable annihilation and hard spectator scattering amplitudes, respectively. Based on $\\chi^2$ analyses, it is observed that (1) The topology-dependent parameterization scheme is feasible for $B\\to PV$ decays; (2) At the current accuracy of experimental measurements and theoretical evaluations, $X_H=X_A^i$ is allowed by $B\\to PV$ decays, but $X_{H}\
Search for a light Higgs boson decaying to two gluons or ss? in the radiative decays of ?(1S)
Cowan, Ray Franklin
We search for the decay ?(1S)??A[superscript 0], A[superscript 0]?gg or ss? , where A[superscript 0] is the pseudoscalar light Higgs boson predicted by the next-to-minimal supersymmetric Standard Model. We use a sample of ...
The ephemeris, orbital decay, and masses of 10 eclipsing HMXBs
Falanga, M; Lutovinov, A; Bonnet-Bidaud, J M; Fetisova, Y; Puls, J
2015-01-01T23:59:59.000Z
We take advantage of more than 10 years of monitoring of the eclipsing HMXB systems LMC X-4, Cen X-3, 4U 1700-377, 4U 1538-522, SMC X-1, IGR J18027-2016, Vela X-1, IGR J17252-3616, XTE J1855-026, and OAO 1657-415 with the ASM on-board RXTE and ISGRI on-board INTEGRAL to update their ephemeris. These results are used to refine previous measurements of the orbital period decay of all sources (where available) and provide the first accurate values of the apsidal advance in Vela X-1 and 4U 1538-522. Updated values for the masses of the neutron stars hosted in the ten HMXBs are also provided, as well as the long-term lightcurves folded on the sources best determined orbital parameters. These lightcurves reveal complex eclipse ingresses and egresses, that are understood mostly as being due to the presence of accretion wakes. The results reported in this paper constitute a database to be used for population and evolutionary studies of HMXBs, as well as theoretical modelling of long-term accretion in wind-fed X-ray b...
IS THE NON OBSERVATION OF NEUTRINOLESS DOUBLE BETA DECAY A QUESTION OF SENSITIVITY?
Paris-Sud XI, Université de
1 IS THE NON OBSERVATION OF NEUTRINOLESS DOUBLE BETA DECAY A QUESTION OF SENSITIVITY? TSAN UNG CHAN Grenoble Cedex FRANCE The hypothetical neutrinoless double beta decay is possible only if the neutrino. This contradiction would lead to conclude that neutrinoless double beta decay could not take place in nature
SEARCH FOR NEUTRINOLESS DOUBLE BETA DECAY WITH THE NEMO-3 DETECTOR : FIRST RESULTS
Boyer, Edmond
1 SEARCH FOR NEUTRINOLESS DOUBLE BETA DECAY WITH THE NEMO-3 DETECTOR : FIRST RESULTS D. LALANNE to searching for neutrinoless double beta decay (0). The expected performance of the detector has been, no evidence for neutrinoless double beta decay (0) was found from ~7 kg of 100 Mo and ~1 kg of 82 Se
Particle decay processes, the quantum Zeno effect and the continuity of time
George Jaroszkiewicz; Jon Eakins
2006-10-24T23:59:59.000Z
Signal-state quantum mechanics is used to discuss quantum mechanical particle decay probabilities and the quantum Zeno effect. This approach avoids the assumption of continuous time, conserves total probability and requires neither non-Hermitian Hamiltonians nor the ad-hoc introduction of complex energies. The formalism is applied to single channel decays, the ammonium molecule, and neutral Kaon decay processes.
Fregolente, Douglas; Matsas, George E. A.; Vanzella, Daniel A. T. [Instituto de Fisica Teorica, Universidade Estadual Paulista, R. Pamplona 145, 01405-900, Sao Paulo, Sao Paulo (Brazil); Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Cx. Postal 369, 13560-970, Sao Carlos, Sao Paulo (Brazil)
2006-08-15T23:59:59.000Z
We investigate the possible decay of protons in geodesic circular motion around neutral compact objects. Weak and strong decay rates and the associated emitted powers are calculated using a semiclassical approach. Our results are discussed with respect to distinct ones in the literature, which consider the decay of accelerated protons in electromagnetic fields. A number of consistency checks are presented along the paper.
Double beta decay, Majorana neutrinos, and neutrino mass Frank T. Avignone III*
Engel, Jonathan
The theoretical and experimental issues relevant to neutrinoless double beta decay are reviewed. The impact more sensitive, even the nonobservation of neutrinoless double beta decay will be useful Acknowledgments 513 References 514 I. INTRODUCTION Neutrinoless double beta decay 0 is a very slow lepton
ß-delayed ?-proton Decay in 56Zn: Analysis of the Charged-particle Spectrum
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Orrigo, S.E.A.; Rubio, B.; Fujita, Y.; Blank, B.; Gelletly, W.; Agramunt, J.; Algora, A.; Ascher, P.; Bilgier, B.; Cáceres, L.; et al
2015-01-01T23:59:59.000Z
A study of the ? decay of the proton-rich Tz = -2 nucleus 56Zn has been reported in a recent publication. A rare and exotic decay mode, ?-de-layed ?-proton decay, has been observed there for the first time in the fp shell. Here, we expand on some of the details of the data analysis, focussing on the charged particle spectrum.
McCollum, Barry
Electromagnetism-like Mechanism with Force Decay Rate Great Deluge for the Course Timetabling called Electromagnetism-like mechanism with force decay rate great deluge algorithm for university course on these benchmark problems. Keywords: Electromagnetism-like mechanism, force decay rate great deluge, course
A note on the neutrino decay line and the possibilities of its detection
Srdjan Samurovic; Vladan Celebonovic
1995-12-06T23:59:59.000Z
Using simple physical reasoning we have estimated the wavelengths and line-widths of spectral lines arising from the decays of massive neutrinos. We have, also, to some extent, discussed the possible consequences of these decays in observable astrophysical settings. We have compared our conclusions with the predictions of the decaying dark matter (DDM) model and cold + hot dark matter (${\\rm C\
Current Research on Wood Decay in the USDA Forest Service1 Harold H. Burdsall, Jr.2
Current Research on Wood Decay in the USDA Forest Service1 Harold H. Burdsall, Jr.2 Abstract, Biodeterioration Research, concentrates on studying the basic mechanism of wood decay. Most of the Forest Service's work on wood decay is being done in two work units in Forest Insect and Disease Research (FIDR) housed
Hibbett, David S.
PROJECT SUMMARY Wood-decaying Agaricomycetes (Basidiomycota) include diverse polypores, gilled production. Understanding of the higher-level relationships of wood-decaying Agaricomycetes has advanced. This project will perform monographic research and training in two major groups of wood-decaying Agaricomycetes
DISCOVERY OF THE TWO-NEUTRINO DOUBLE-BETA DECAY OF XENON-136 WITH EXO-200
Gratta, Giorgio
mass differences, not the absolute mass scale. Neutrinoless double-beta decay, a hypothetical nuclear, and is located deep underground in a New Mexico salt mine to evade cosmic rays. Neutrinoless double-beta decay to measure. Neutrinoless double-beta decay can be used to measure the neutrino mass--until recently believed
Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group
Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Robert A. Johnson Chair of the Supervisory Committee: Professor John F. Wilkerson Physics The observation of neutrinoless double-beta decay
Uncertainties in Nuclear Matrix Elements for Neutrinoless Double-Beta Decay
Engel, Jonathan
Uncertainties in Nuclear Matrix Elements for Neutrinoless Double-Beta Decay Jonathan Engel Abstract. I briefly review calculations of the matrix elements governing neutrinoless double-beta decay;Uncertainties in Nuclear Matrix Elements for Neutrinoless Double-Beta Decay 2 in reducing theoretical error
ß-delayed ?-proton decay in ??Zn: Analysis of the charged-particle spectrum
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Orrigo, S. E.A.; Rubio, B.; Fujita, Y.; Blank, B.; Gelletly, W.; Agramunt, J.; Algora, A.; Ascher, P.; Bilgier, B.; Cáceres, L.; et al
2015-01-01T23:59:59.000Z
A study of the ? decay of the proton-rich Tz = –2 nucleus ??Zn has been reported in a recent publication. A rare and exotic decay mode, ?-de-layed ?-proton decay, has been observed there for the first time in the fp shell. Here, we expand on some of the details of the data analysis, focusing on the charged particle spectrum.
Neutrinoless Double Beta Decay in Type I+II Seesaw Models
Borah, Debasish
2015-01-01T23:59:59.000Z
We study neutrinoless double beta decay in left-right symmetric extension of the standard model with type I and type II seesaw origin of neutrino masses. Due to the enhanced gauge symmetry as well as extended scalar sector, there are several new physics sources of neutrinoless double beta decay in this model. Ignoring the left-right gauge boson mixing and heavy-light neutrino mixing, we first compute the contributions to neutrinoless double beta decay for type I and type II dominant seesaw separately and compare with the standard light neutrino contributions. We then repeat the exercise by considering the presence of both type I and type II seesaw, having non-negligible contributions to light neutrino masses and show the difference in results from individual seesaw cases. Assuming the new gauge bosons and scalars to be around a TeV, we constrain different parameters of the model including both heavy and light neutrino masses from the requirement of keeping the neutrinoless double beta decay amplitude below th...
Neutrinoless Double Beta Decay in Type I+II Seesaw Models
Debasish Borah; Arnab Dasgupta
2015-09-06T23:59:59.000Z
We study neutrinoless double beta decay in left-right symmetric extension of the standard model with type I and type II seesaw origin of neutrino masses. Due to the enhanced gauge symmetry as well as extended scalar sector, there are several new physics sources of neutrinoless double beta decay in this model. Ignoring the left-right gauge boson mixing and heavy-light neutrino mixing, we first compute the contributions to neutrinoless double beta decay for type I and type II dominant seesaw separately and compare with the standard light neutrino contributions. We then repeat the exercise by considering the presence of both type I and type II seesaw, having non-negligible contributions to light neutrino masses and show the difference in results from individual seesaw cases. Assuming the new gauge bosons and scalars to be around a TeV, we constrain different parameters of the model including both heavy and light neutrino masses from the requirement of keeping the neutrinoless double beta decay amplitude below the upper limit set by the GERDA experiment.
Novel Higgs-to-125 GeV Higgs boson decays in the complex NMSSM
Shoaib Munir
2014-05-05T23:59:59.000Z
In the Next-to-Minimal Supersymmetric Standard Model (NMSSM) a variety of parameter configurations yields a Higgs boson consistent with the one observed at the LHC. Additionally, the Higgs sector of the model can contain explicit CP-violating phases even at the tree level, in contrast with the Minimal Supersymmetric Standard Model (MSSM). In this article we present the one-loop Higgs boson mass matrix of the complex NMSSM in the renormalisation-group-improved effective potential approach. We also present the trilinear Higgs boson self-couplings as well as various partial decay widths of a generic CP-mixed Higgs boson in the model. We then analyse a very interesting phenomenological scenario wherein the decay of a relatively light pseudoscalar-like Higgs boson into ~ 125 GeV SM-like Higgs boson(s) is induced by non-zero CP-violating phases. We discuss in detail a few benchmark cases in which such a decay can contribute significantly to the production of SM-like Higgs bosons at the LHC on top of the gluon fusion process. It can thus be partially responsible for the gamma.gamma excess near 125 GeV due to the subsequent decay of the SM-like Higgs boson. Such a scenario is extremely difficult to realize in the complex MSSM and, if probed at the LHC, it could provide an indication of the non-minimal nature of supersymmetry.
Solar Influence on Nuclear Decay Rates: Constraints from the MESSENGER Mission
Ephraim Fischbach; K. Joseph Chen; Robert E. Gold; John O. Goldsten; David J. Lawrence; Ralph J. McNutt Jr.; Edgar A. Rhodes; Jere H. Jenkins; James M. Longuski
2011-09-01T23:59:59.000Z
We have analyzed Cs-137 decay data, obtained from a small sample onboard the MESSENGER spacecraft en route to Mercury, with the aim of setting limits on a possible correlation between nuclear decay rates and solar activity. Such a correlation has been suggested recently on the basis of data from Mn-54 decay during the solar flare of 13 December 2006, and by indications of an annual and other periodic variations in the decay rates of Si-32, Cl-36, and Ra-226. Data from five measurements of the Cs-137 count rate over a period of approximately 5.4 years have been fit to a formula which accounts for the usual exponential decrease in count rate over time, along with the addition of a theoretical solar contribution varying with MESSENGER-Sun separation. The indication of solar influence is then characterized by a non-zero value of the calculated parameter \\xi, and we find \\xi=(2.8+/-8.1)x10^{-3} for Cs-137. A simulation of the increased data that can hypothetically be expected following Mercury orbit insertion on 18 March 2011 suggests that the anticipated improvement in the determination of \\xi could reveal a non-zero value of \\xi if present at a level consistent with other data.
Measurement of time-dependent CP violation in B0 ? ?'K0 decays
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Šantelj, L.; Yusa, Y.; Abdesselam, A.; Adachi, I.; Aihara, H.; Al Said, S.; Asner, D. M.; Aulchenko, V.; Aushev, T.; Ayad, R.; et al
2014-10-29T23:59:59.000Z
We present a measurement of the time-dependent CP violation parameters in B0 ? ?'K0 decays. The measurement is based on the full data sample containing 772×106 BB¯ pairs collected at the ?(4S) resonance using the Belle detector at the KEKB asymmetric-energy e+e- collider. The measured values of the mixing-induced and direct CP violation parameters are: sin 2?eff1 = +0.68 ± 0.07 ± 0.03, A?'K0 = +0.03 ± 0.05 ± 0.04, where the first uncertainty is statistical and the second is systematic. The values obtained are the most accurate to date. Furthermore, these results are consistent with our previous measurements andmore »with the world-average value of sin 2?1 measured in B0 ? J/?K0 decays.« less
Measurement of the Moments of the Hadronic Invariant Mass Distribution in Semileptonic Beta Decays
Acosta, D.; The CDF Collaboration TITLE=Measuremen
2005-03-13T23:59:59.000Z
Using 180 pb{sup -1} of data collected with the CDF II detector at the Tevatron, we measure the first two moments of the hadronic invariant mass-squared distribution in charmed semileptonic B decays. From these we determine the non-perturbative Heavy Quark Effective Theory parameters {Lambda} and {lambda}{sub 1} used to relate the B meson semileptonic branching ratio to the CKM matrix element |V{sub cb}|.
Phi decay: a relevant source for K- production at SIS energies?
The HADES Collaboration; G. Agakishiev; A. Balanda; B. Bannier; R. Bassini; D. Belver; A. V. Belyaev; A. Blanco; M. Boehmer; J. L. Boyard; P. Braun-Munzinger; P. Cabanelas; E. Castro; S. Chernenko; T. Christ; M. Destefanis; J. Diaz; F. Dohrmann; A. Dybczak; T. Eberl; W. Enghardt; L. Fabbietti; O. V. Fateev; P. Finocchiaro; P. Fonte; J. Friese; I. Froehlich; T. Galatyuk; J. A. Garzon; R. Gernhaeuser; A. Gil1; C. Gilardi; M. Golubeva; D. Gonzalez-Diaz; F. Guber; M. Heilmann; T. Heinz; T. Hennino; R. Holzmann; A. Ierusalimov; I. Iori; A. Ivashkin; M. Jurkovic; B. Kaempfer; K. Kanaki; T. Karavicheva; D. Kirschner; I. Koenig; W. Koenig; B. W. Kolb; R. Kotte; F. Krizek; R. Kruecken; W. Kuehn; A. Kugler; A. Kurepin; S. Lang; J. S. Lange; K. Lapidus; T. Liu; L. Lopes; M. Lorenz; L. Maier; A. Mangiarotti; J. Markert; V. Metag; B. Michalska; J. Michel; D. Mishra; E. Moriniere; J. Mousa; C. Muentz; L. Naumann; J. Otwinowski; Y. C. Pachmayer; M. Palka; Y. Parpottas; V. Pechenov; O. Pechenova; T. PerezCavalcanti; J. Pietraszko; W. Przygoda; B. Ramstein; A. Reshetin; M. Roy-Stephan; A. Rustamov; A. Sadovsky; B. Sailer; P. Salabura; A. Schmah; E. Schwab; Yu. G. Sobolev; S. Spataro; B. Spruck; H. Stroebele; J. Stroth; C. Sturm; M. Sudol; A. Tarantola; K. Teilab; P. Tlusty; M. Traxler; R. Trebac; H. Tsertos; V. Wagner; M. Weber; M. Wisniowski; T. Wojcik; J. Wuestenfel; S. Yurevich; Y. V. Zanevsky; P. Zhou; P. Zumbruch
2009-02-20T23:59:59.000Z
We present phase space distributions and multiplicities of K+, K- and phi mesons produced in Ar+KCl reactions at a kinetic beam energy of 1.756 AGeV and measured with the HADES spectrometer. The inverse slope parameters and yields of kaons supplement the systematics of previous measurements. The percentage of K- mesons coming fromphi decay is found to be 18+- 7%.
First measurement of suppressed B- -> D0 K- decays through the ADS method in hadron collisions
Paola Garosi; for the CDF Collaboration
2011-10-11T23:59:59.000Z
We report the first measurement of branching fractions and CP-violating asymmetries of suppressed B- -> DK- decays in hadron collisions, using the approach proposed by Atwood, Dunietz, and Soni (ADS) to determine the CKM angle gamma in 7.0 fb^-1 of data. The ADS parameters are determined with accuracy comparable with B-factory measurements and significantly improve the global knowledge of the angle gamma.
First measurement of suppressed B- -> D0 K- decays through the ADS method in hadron collisions
Garosi, Paola
2011-01-01T23:59:59.000Z
We report the first measurement of branching fractions and CP-violating asymmetries of suppressed B- -> DK- decays in hadron collisions, using the approach proposed by Atwood, Dunietz, and Soni (ADS) to determine the CKM angle gamma in 7.0 fb^-1 of data. The ADS parameters are determined with accuracy comparable with B-factory measurements and significantly improve the global knowledge of the angle gamma.
Test of Special Relativity and Equivalence Principle from Neutrinoless Double Beta Decay
H. V. Klapdor--Kleingrothaus; H. Päs; U. Sarkar
1998-09-15T23:59:59.000Z
We generalize the formalism for testing Lorentz invariance and the equivalence principle in the neutrino sector. While neutrino oscillation bounds constrain the region of large mixing of the the weak and gravitational eigenstates, we obtain new constraints on violations of Lorentz invariance and the equivalence principle from neutrinoless double beta decay. These bounds apply even in the case of no mixing and thus probe a totally unconstrained region in the parameter space.
Energy distributions from three-body decaying many-body resonances
R. Alvarez-Rodriguez; A. S. Jensen; D. V. Fedorov; H. O. U. Fynbo; E. Garrido
2007-07-01T23:59:59.000Z
We compute energy distributions of three particles emerging from decaying many-body resonances. We reproduce the measured energy distributions from decays of two archetypal states chosen as the lowest $0^{+}$ and $1^{+}$-resonances in $^{12}$C populated in $\\beta$-decays. These states are dominated by sequential, through the $^{8}$Be ground state, and direct decays, respectively. These decay mechanisms are reflected in the ``dynamic'' evolution from small, cluster or shell-model states, to large distances, where the coordinate or momentum space continuum wavefunctions are accurately computed.
0+ -> 2+ neutrinoless double beta decay triggered directly by the Majorana neutrino mass
T. Tomoda
1999-09-12T23:59:59.000Z
We treat 0+ -> 2+ neutrinoless double beta decays taking into account recoil corrections to the nuclear currents. The decay probability can be written as a quadratic form of the effective coupling constants of the right-handed leptonic currents and the effective neutrino mass. We calculate the nuclear matrix elements for the 0+ -> 2+ neutrinoless double beta decays of 76Ge and 100Mo, and demonstrate that the relative sensitivities of 0+ -> 2+ decays to the neutrino mass and the right-handed currents are comparable to those of 0+ -> 0+ decays.
Dynamical control of two-level system's decay and long time freezing
Wenxian Zhang; Jun Zhuang
2010-01-07T23:59:59.000Z
We investigate with exact numerical calculation coherent control of a two-level quantum system's decay by subjecting the two-level system to many periodic ideal $2\\pi$ phase modulation pulses. For three spectrum intensities (Gaussian, Lorentzian, and exponential), we find both suppression and acceleration of the decay of the two-level system, depending on difference between the spectrum peak position and the eigen frequency of the two-level system. Most interestingly, the decay of the two-level system freezes after many control pulses if the pulse delay is short. The decay freezing value is half of the decay in the first pulse delay.
Extra dimensions and neutrinoless double beta decay experiments
Gozdz, Marek; Kaminski, Wieslaw A.; Faessler, Amand [Theoretical Physics Department, Maria Curie-Sklodowska University, Lublin (Poland); Institute fuer Theoretische Physik, Universitaet Tuebingen, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)
2005-05-01T23:59:59.000Z
The neutrinoless double beta decay is one of the few phenomena, belonging to the nonstandard physics, which is extensively being sought for in experiments. In the present paper the link between the half-life of the neutrinoless double beta decay and theories with large extra dimensions is explored. The use of the sensitivities of currently planned 0{nu}2{beta} experiments: DAMA, CANDLES, COBRA, DCBA, CAMEO, GENIUS, GEM, MAJORANA, MOON, CUORE, EXO, and XMASS, gives the possibility for a nondirect 'experimental' verification of various extra dimensional scenarios. We discuss also the results of the Heidelberg-Moscow Collaboration. The calculations are based on the Majorana neutrino mass generation mechanism in the Arkani-Hamed-Dimopoulos-Dvali model.
The Search for Neutrinoless Double Beta Decay in CUORE
L. M. Ejzak; for the CUORE Collaboration
2009-10-15T23:59:59.000Z
Understanding the nature of neutrino masses will require physics beyond the long-standing Standard Model of particle physics. Neutrinoless double beta decay experiments like the Cryogenic Underground Observatory for Rare Events (CUORE) are uniquely suited for probing the remaining mysteries of neutrino mass, particularly the question of the neutrino's Majorana nature. CUORE will be a next-generation experiment at the Laboratori Nazionali del Gran Sasso in Italy; it will consist of an array of 988 TeO2 detector crystals operated at ~10 mK, following the bolometric technique established by the Cuoricino experiment. It will look for the energy signal produced by the theoretically-predicted neutrinoless double beta decay in Te-130, and therefore reliable energy calibration of the detector is crucial to the experiment's success. We will present the most recent results from Cuoricino and discuss the current status of the CUORE project, with a particular emphasis on the development of the calibration system.