Uncertainty evaluation of delayed neutron decay parameters
Wang, Jinkai
2009-05-15T23:59:59.000Z
.......... 80 Figure 6.1 Fitted E2 from Different Algorithms (Saturation Mode)................... 85 Figure 6.2 Standard Deviations of Fitted Parameter Ratios (Saturation Mode). 92 Figure 6.3 Standard Deviations of Fitted Parameter Ratios (Pulse Mode...)......... 92 Figure 6.4 Standard Deviations of Fitted Parameter Ratios with Group-1 Fixed (Pulse Mode) ........................................................................... 93 Figure 6.5 The Ratios of Different Data Sets to Keepin?s Values...
Measurement of the asymmetry parameter for the decay {Lambda}{yields}p{pi}{sup +}
Ablikim, M.; Bai, J. Z.; Bai, Y.; Cai, X.; Chen, H. S.; Chen, H. X.; Chen, J. C.; Chen, Jin; Chen, Y. B.; Chu, Y. P.; Deng, Z. Y.; Du, S. X.; Fang, J.; Fu, C. D.; Gao, C. S.; Gu, S. D.; Guo, Y. N.; He, K. L.; Heng, Y. K.; Hu, H. M. [Institute of High Energy Physics, Beijing 100049 (China)
2010-01-01T23:59:59.000Z
Based on a sample of 58x10{sup 6}J/{psi} decays collected with the BESII detector at the BEPC, the {Lambda} decay parameter {alpha}{sub {Lambda}}for {Lambda}{yields}p{pi}{sup +} is measured using about 9000 J/{psi}{yields}{Lambda}{Lambda}{yields}pp{pi}{sup +{pi}-} decays. A fit to the joint angular distributions yields {alpha}{sub {Lambda}({Lambda}{yields}p{pi}{sup +})}=-0.755{+-}0.083{+-}0.063, where the first error is statistical, and the second systematic.
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 measurement of the Michel parameters in leptonic decays of the tau
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan
1997-06-01T23:59:59.000Z
We have measured the spectral shape Michel parameters rho and eta using leptonic decays of the tau, recorded by the CLEO II detector. Assuming e-mu universality in the vectorlike couplings, we find rho(e mu) = 0.735 +/- 0.013 +/- 0.008 and eta(e mu...
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...
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. ...
Luth, Vera G.; /SLAC
2012-10-02T23:59:59.000Z
The following is an overview of the measurements of the CKM matrix elements |V{sub cb}| and |V{sub ub}| that are based on detailed studies of semileptonic B decays by the BABAR and Belle Collaborations and major advances in QCD calculations. In addition, a new and improved measurement of the ratios R(D{sup (*)}) = {Beta}({bar B} {yields} D{sup (*)}{tau}{sup -}{bar {nu}}{sub {tau}})/{Beta}({bar B} {yields} D{sup (*)}{ell}{sup -}{bar {nu}}{sub {ell}}) is presented. Here D{sup (*)} refers to a D or a D* meson and {ell} is either e or {mu}. The results, R(D) = 0.440 {+-} 0.058 {+-} 0.042 and R(D*) = 0.332 {+-} 0.024 {+-} 0.018, exceed the Standard Model expectations by 2.0{sigma} and 2.7{sigma}, respectively. Taken together, they disagree with these expectations at the 3.4{sigma} level. The excess of events cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.
Constraints on light neutrino parameters derived from the study of neutrinoless double beta decay
Stoica, Sabin
2014-01-01T23:59:59.000Z
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 ...
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.
Cosmology with decaying particles
Turner, M.S.
1984-09-01T23:59:59.000Z
We consider a cosmological model in which an unstable massive relic particle species (denoted by X) has an initial mass density relative to baryons ..beta../sup -1/ identically equal rho/sub X//rho/sub B/ >> 1, and then decays recently (redshift z less than or equal to 1000) into particles which are still relativistic today (denoted by R). We write down and solve the coupled equations for the cosmic scale factor a(t), the energy density in the various components (rho/sub X/, rho/sub R/, rho/sub B/), and the growth of linear density perturbations (delta rho/rho). The solutions form a one parameter (..beta..) family of solutions; physically ..beta../sup -1/ approx. = (..cap omega../sub R//..cap omega../sub NR/) x (1 + z/sub D/) = (ratio today of energy density of relativistic to nonrelativistic particles) x (1 + redshift of (decay)). We discuss the observational implications of such a cosmological model and compare our results to earlier results computed in the simultaneous decay approximation. In an appendix we briefly consider the case where one of the decay products of the X is massive and becomes nonrelativistic by the present epoch. 21 references.
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.
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.
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).
Double Beta Decay: Scintillators
Mark C. Chen
2008-10-20T23:59:59.000Z
Scintillator detectors can be used in experiments searching for neutrinoless double beta decay. A wide variety of double beta decay candidate isotopes can be made into scintillators or can be loaded into scintillators. Experimental programs developing liquid xenon, inorganic crystals, and Nd-loaded liquid scintillator are described in this review. Experiments with 48Ca and 150Nd benefit from their high endpoint which places the neutrinoless double beta decay signal above most backgrounds from natural radioactivity.
Anirban Kundu
2002-05-10T23:59:59.000Z
I discuss how supersymmetry affects various observables in B decays, and point out the interesting channels in the context of B factories.
A. S. Barabash
2006-02-22T23:59:59.000Z
The present status of double beta decay experiments are reviewed. The results of the most sensitive experiments, NEMO-3 and CUORICINO, are discussed. Proposals for future double beta decay experiments are considered. In these experiments sensitivity for the effective neutrino mass will be on the level of (0.1-0.01) eV.
A. S. Barabash
2011-07-28T23:59:59.000Z
The present status of double beta decay experiments is reviewed. The results of the most sensitive experiments are discussed. Proposals for future double beta decay experiments with a sensitivity to the $$ at the level of (0.01--0.1) eV are considered.
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.
LITTENBERG, L.
2005-07-19T23:59:59.000Z
Lepton flavor violation (LFV) experiments have probed sensitivities corresponding to mass scales of well over 100 TeV, making life difficult for models predicting accessible LFV in kaon decay and discouraging new dedicated experiments of this type.
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.
Constraining Decaying Dark Matter
Ran Huo
2011-07-13T23:59:59.000Z
We revisited the decaying dark matter (DDM) model, in which one collisionless particle decays early into two collisionless particles, that are potentially dark matter particles today. The effect of DDM will be manifested in the cosmic microwave background (CMB) and structure formation. With a systematic modification of CMB calculation tool \\texttt{camb}, we can numerically calculated this effect, and compare it to observations. Further Markov Chain Monte Carlo \\texttt{cosmomc} runnings update the constraints in that model: the free streaming length $\\lambda_{FS}\\lesssim0.5$Mpc for nonrelativistic decay, and $((M_{DDM}/keV) Y)^2 (T_d/yr)\\lesssim5\\times10^{-5}$ for relativistic decay.
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
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.
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$.
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\
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.
Baringer, Philip S.; Bean, Alice; Chen, G.; Clutter, Justace Randall; Sekaric, Jadranka; Wilson, Graham Wallace; Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.
2013-06-12T23:59:59.000Z
Measurement of direct CP violation parameters in B#1; ! J=cK#1; and B#1; ! J=c#1;#1; decays with 10:4 fb#2;1 of Tevatron data V.M. Abazov,31 B. Abbott,66 B. S. Acharya,25 M. Adams,45 T. Adams,43 J. P. Agnew,40 G.D. Alexeev,31 G. Alkhazov,35 A. Alton..., Seattle, Washington 98195, USA (Received 8 April 2013; published 12 June 2013) We present a measurement of the direct CP-violating charge asymmetry in B#1; mesons decaying to J=cK#1; and J=c#1;#1; where J=c decays to #2;þ#2;#2;, using the full run II data...
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.
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.
Baringer, Philip S.
1990-03-01T23:59:59.000Z
— wW~ ii~ ~ + v~ 1''&WV'' V 0.20 0.45 0.70 ~y ~ EBFA~ 0.95 l.20 FIG. 4. Energy spectrum (normalized to beam energy) for Y~y2(h+h ) event candidates, with continuum data and ex- pected background from Y~m 2(h +h ) overplotted. 40 30— ~ 20— LLI IO— hl...PHYSICAL REVIEW 0 VOLUME 41, NUMBER 5 Radiative T(lS) decays 1 MARCH 1990 R. Fulton, M. Hempstead, T. Jensen, D. R. Johnson, H. Kagan, R. Kass, F. Morrow, and J. Whitmore Ohio State University, Columbus, Ohio 43210 W.-Y. Chen, J. Dominick, R. L. Mc...
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.
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.
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...
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
Wujun Huo; Xinmin Zhang; Tao Huang
2002-03-20T23:59:59.000Z
Recently BES at BEPC found evidence for the existence of the $\\sigma$ meson in the process of $J/\\Psi \\to \\sigma\\omega \\to\\pi\\pi\\omega$. In this paper we firstly discuss the relevant coupling $g_{\\sigma\\pi\\pi}$ and show that the linear $\\sigma$ model gives rise to a reasonable description of the $\\sigma$ decay into $\\pi$'s, then we calculate the coupling constant $g^{th}_{J/\\Psi\\sigma\\omega}$ by using the perturbative QCD technique and the light-cone wave functions of the $\\sigma$ and $\\omega$ mesons. The results show that the theoretical value of $g^{th}_{J/\\Psi\\sigma\\omega}$ is within the range of experimental value $g_{J/\\Psi\\sigma\\omega}$.
Can Dark Matter Decay in Dark Energy?
S. H. Pereira; J. F. Jesus
2009-02-26T23:59:59.000Z
We analyze the interaction between Dark Energy and Dark Matter from a thermodynamical perspective. By assuming they have different temperatures, we study the possibility of occurring a decay from Dark Matter into Dark Energy, characterized by a negative parameter $Q$. We find that, if at least one of the fluids has non vanishing chemical potential, for instance $\\mu_x0$, the decay is possible, where $\\mu_x$ and $\\mu_{dm}$ are the chemical potentials of Dark Energy and Dark Matter, respectively. Using recent cosmological data, we find that, for a fairly simple interaction, the Dark Matter decay is favored with a probability of $\\sim 93%$ over the Dark Energy decay. This result comes from a likelihood analysis where only background evolution has been considered.
Double beta decay: present status
A. S. Barabash
2008-07-18T23:59:59.000Z
The present status of double beta decay experiments (including the search for $2\\beta^{+}$, EC$\\beta^{+}$ and ECEC processes) are reviewed. The results of the most sensitive experiments are discussed. Average and recommended half-life values for two-neutrino double beta decay are presented. Conservative upper limits on effective Majorana neutrino mass and the coupling constant of the Majoron to the neutrino are established as $ beta decay experiments with a sensitivity for the $$ at the level of (0.01-0.1) eV are considered.
Andrey Beresnyak; Alex Lazarian
2008-05-06T23:59:59.000Z
We present a model for nonlinear decay of the weak wave in three-dimensional incompressible magnetohydrodynamic (MHD) turbulence. We show that the decay rate is different for parallel and perpendicular waves. We provide a general formula for arbitrarily directed waves and discuss particular limiting cases known in the literature. We test our predictions with direct numerical simulations of wave decay in three-dimensional MHD turbulence, and discuss the influence of turbulent damping on the development of linear instabilities in the interstellar medium and on other important astrophysical processes.
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^{+}\
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.
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
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.
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.
Neutrinoless Double Beta-Decay
S. M. Bilenky
2010-01-12T23:59:59.000Z
The neutrinoless double $\\beta$-decay of nuclei is reviewed. We discuss neutrino mixing and 3x3 PMNS neutrino mixing matrix. Basic theory of neutrinoless double $\\beta$-decay is presented in some details. Results of different calculations of nuclear matrix element are discussed. Experimental situation is considered. The Appendix is dedicated to E. Majorana (brief biography and his paper in which the theory of Majorana particles is given)
Beta and gamma decays April 9, 2002
Landstreet, John D.
Beta and gamma decays April 9, 2002 1 Simple Fermi theory of beta decay Â² Beta decay is one by the emission of a positive or negative beta particle (positron or electron). To ensure conservation of lepton emitted in beta decay is a continuum of energies, up to a maximum value, with most emitted betas having
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.
Measurement of $J/\\psi\\to\\gamma\\eta_{\\rm c}$ decay rate and $\\eta_{\\rm c}$ parameters at KEDR
Anashin, V V; Baldin, E M; Barladyan, A K; Barnyakov, A Yu; Barnyakov, M Yu; Baru, S E; Basok, I Yu; Bedny, I V; Blinov, A E; Blinov, V E; Bobrov, A V; Bobrovnikov, V S; Bogomyagkov, A V; Bondar, A E; Buzykaev, A R; Eidelman, S I; Glukhovchenko, Yu M; Gulevich, V V; Gusev, D V; Karnaev, S E; Karpov, G V; Karpov, S V; Kharlamova, T A; Kiselev, V A; Kononov, S A; Kotov, K Yu; Kravchenko, E A; Kulikov, V F; Kurkin, G Ya; Kuper, E A; Levichev, E B; Maksimov, D A; Malyshev, V M; Maslennikov, A L; Medvedko, A S; Meshkov, O I; Mishnev, S I; Morozov, I I; Muchnoi, N Yu; Neufeld, V V; Nikitin, S A; Nikolaev, I B; Okunev, I N; Onuchin, A P; Oreshkin, S B; Orlov, I O; Osipov, A A; Peleganchuk, S V; Pivovarov, S G; Piminov, P A; Petrov, V V; Poluektov, A O; Pospelov, G E; Prisekin, V G; Rezanova, O L; Ruban, A A; Sandyrev, V K; Savinov, G A; Shamov, A G; Shatilov, D N; Shwartz, B A; Simonov, E A; Sinyatkin, S V; Skrinsky, A N; Smaluk, V V; Sokolov, A V; Sukharev, A M; Starostina, E V; Talyshev, A A; Tayursky, V A; Telnov, V I; Tikhonov, Yu A; Todyshev, K Yu; Tumaikin, G M; Usov, Yu V; Vorobiov, A I; Yushkov, A N; Zhilich, V N; Zhulanov, V V; Zhuravlev, A N
2014-01-01T23:59:59.000Z
Using the inclusive photon spectrum based on a data sample collected at the $J/\\psi$ peak with the KEDR detector at the VEPP-4M $e^+e^-$ collider, we measured the rate of the radiative decay $J/\\psi\\to\\gamma\\eta_{\\rm c}$ as well as $\\eta_{\\rm c}$ mass and width. Taking into account an asymmetric photon lineshape we obtained: $\\Gamma^0_{\\gamma\\eta_{\\rm c}}=2.98\\pm0.18 \\phantom{|}^{+0.15}_{-0.33}$ keV, $M_{\\eta_{\\rm c}} = 2983.5 \\pm 1.4 \\phantom{|}^{+1.6}_{-3.6}$ MeV/$c^2$, $\\Gamma_{\\eta_{\\rm c}} = 27.2 \\pm 3.1 \\phantom{|}^{+5.4}_{-2.6}$ MeV.
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)
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...
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.
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.}
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.
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.
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.
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
Higgs Bosons from Top Quark Decays
Tao Han; Richard Ruiz
2014-04-28T23:59:59.000Z
In light of the discovery of a Standard Model (SM)-like Higgs boson ($h$) at the LHC, we investigate the top quark to Higgs boson transition $t\\rightarrow W^{*}bh$, which is the leading $t\\to h$ decay mode in the SM. We find the decay branching fraction to be $1.80\\times 10^{-9}$. In comparison, the two-body, loop-induced $t\\rightarrow ch$ transition occurs at $\\sim10^{-14}$ in the SM. We consider the consequences of gauge invariant dimension-6 operators affecting the $t\\bar{t}h$ interaction and find that the decay branching fraction may be increased by a factor of two within current constraints on the coupling parameters from collider experiments. We also extend the calculation to the CP-conserving Type I and Type II Two Higgs Doublet Models (2HDM), including both CP-even and CP-odd Higgs bosons. For neutral scalar masses at about $100$ GeV, the decay rates can be several times larger than the SM result in the allowed range of model parameters. Observation prospects at present and future colliders are briefly addressed.
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.
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...
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.
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
from the ex- perimental ft value for a 01?01 b decay between analog states with the relation @3# 0556-2813/2003/68~1!/015501~6!/$20.00 68 015501- of 62Ga . Hardy, V. E. Mayes, R. G. Neilson, M. Sanchez-Vega, and R. E. Tribble y, College Station...
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.
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 ...
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.
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.
Imperfect World of $??$-decay Nuclear Data Sets
B. Pritychenko
2015-01-09T23:59:59.000Z
The precision of double-beta ($\\beta\\beta$) decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for $\\beta\\beta$-decay T$_{1/2}^{2\
Light-Quark Decays in Heavy Hadrons
Faller, Sven
2015-01-01T23:59:59.000Z
We consider weak decays of heavy hadrons (bottom and charmed) where the heavy quark acts as a spectator. Theses decays are heavily phase-space suppressed but may become experimentally accessible in the near future. These decays are interesting as a QCD laboratory to study the behaviour of the light quarks in the colour-background field of the heavy spectator.
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.
Dalitz plot studies in hadronic charm decays
Leonard Lesniak
2014-11-06T23:59:59.000Z
Recent studies of hadronic -meson decays are reported. Some experimental searches of CP-symmetry violation using model independent methods are presented. An importance of unitarity constraints in construction of phenomenological models of the D-meson decays is underlined. The theoretical model of the D0 --> K0S pi+ pi- decays, including some two-body unitarity constraints, is described. Then a comparison of the model results with the Belle collaboration data is made. The results on the CP-violation in the D0 --> K0S pi+ pi- decays are given and the necessity to consider the CP-violation in the subsequent K0S decays is emphasized.
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.
International decay data evaluation project
Helmer, R.G.
1996-10-01T23:59:59.000Z
Basic concepts of, and information from, radionuclide decay are used in many applications. The author limits this discussion to the data needed for applied {gamma}-ray spectrometry; this includes applications such as nuclide identification and quantitative assay. Many of these applications require a knowledge of half-lives and radiation energies and emission probabilities. For over 50 years, people have compiled and evaluated measured data with the goal of obtaining the best values of these quantities. This has resulted in numerous sets of recommended values, many of which still have scientific, historical, or national reasons for existing. These sets show varying degrees of agreement and disagreement in the quoted values and varying time lags in incorporating new and improved experimental results. A new informational international group has been formed to carry out evaluations for radionuclides of importance in applications; it is expected that the results will become an authoritative and widely accepted set of decay data.
$\\tau$ decays with neutral kaons
Abbiendi, G; Åkesson, P F; Alexander, Gideon; Allison, J; Anderson, K J; Arcelli, S; Asai, S; Ashby, S F; Axen, D A; Azuelos, Georges; Bailey, I; Ball, A H; Barberio, E; Barlow, R J; Batley, J Richard; Baumann, S; Behnke, T; Bell, K W; Bella, G; Bellerive, A; Bentvelsen, Stanislaus Cornelius Maria; Bethke, Siegfried; Betts, S; Biebel, O; Biguzzi, A; Bloodworth, Ian J; Bock, P; Böhme, J; Boeriu, O; Bonacorsi, D; Boutemeur, M; Braibant, S; Bright-Thomas, P G; Brigliadori, L; Brown, R M; Burckhart, Helfried J; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Chrisman, D; Ciocca, C; Clarke, P E L; Clay, E; Cohen, I; Conboy, J E; Cooke, O C; Couchman, J; Couyoumtzelis, C; Coxe, R L; Cuffiani, M; Dado, S; Dallavalle, G M; Dallison, S; Davis, R; de Roeck, A; Dervan, P J; Desch, Klaus; Dienes, B; Dixit, M S; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Estabrooks, P G; Etzion, E; Fabbri, Franco Luigi; Fanfani, A; Fanti, M; Faust, A A; Feld, L; Ferrari, P; Fiedler, F; Fierro, M; Fleck, I; Frey, A; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Gingrich, D M; Glenzinski, D A; Goldberg, J; Gorn, W; Grandi, C; Graham, K; Gross, E; Grunhaus, Jacob; Gruwé, M; Hajdu, C; Hanson, G G; Hansroul, M; Hapke, M; Harder, K; Harel, A; Hargrove, C K; Harin-Dirac, M; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herten, G; Heuer, R D; Hildreth, M D; Hill, J C; Hobson, P R; Höcker, Andreas; Hoffman, K; Homer, R James; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Imrie, D C; Ishii, K; Jacob, F R; Jawahery, A; Jeremie, H; Jimack, Martin Paul; Jones, C R; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J I; Karapetian, G V; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Kayal, P I; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Klier, A; Kobayashi, T; Kobel, M; Kokott, T P; Kolrep, M; Komamiya, S; Kowalewski, R V; Kress, T; Krieger, P; Von Krogh, J; Kühl, T; Kupper, M; Kyberd, P; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Lauber, J; Lawson, I; Layter, J G; Lellouch, Daniel; Letts, J; Levinson, L; Liebisch, R; Lillich, J; List, B; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Losty, Michael J; Lü, J; Ludwig, J; Macchiolo, A; MacPherson, A L; Mader, W F; Mannelli, M; Marcellini, S; Marchant, T E; Martin, A J; Martin, J P; Martínez, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McKigney, E A; McMahon, T J; McPherson, R A; Meijers, F; Méndez-Lorenzo, P; Merritt, F S; Mes, H; Meyer, I; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Montanari, A; Mori, T; Nagai, K; Nakamura, I; Neal, H A; Nisius, R; O'Neale, S W; Oakham, F G; Odorici, F; Ögren, H O; Okpara, A N; Oreglia, M J; Orito, S; Pásztor, G; Pater, J R; Patrick, G N; Patt, J; Pérez-Ochoa, R; Petzold, S; Pfeifenschneider, P; Pilcher, J E; Pinfold, James L; Plane, D E; Poli, B; Polok, J; Przybycien, M B; Quadt, A; Rembser, C; Rick, Hartmut; Robins, S A; Rodning, N L; Roney, J M; Rosati, S; Roscoe, K; Rossi, A M; Rozen, Y; Runge, K; Runólfsson, O; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sang, W M; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schmitt, S; Schöning, A; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Spagnolo, S; Sproston, M; Stahl, A; Stephens, K; Stoll, K; Strom, D; Ströhmer, R; Surrow, B; Talbot, S D; Taras, P; Tarem, S; Teuscher, R; Thiergen, M; Thomas, J; Thomson, M A; Torrence, E; Towers, S; Trefzger, T M; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Van Kooten, R; Vannerem, P; Verzocchi, M; Voss, H; Wäckerle, F; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; White, J S; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Zacek, V; Zer-Zion, D
2000-01-01T23:59:59.000Z
The branching ratio of the tau lepton to a neutral K meson is measured from a sample of approximately 200,000 tau decays recorded by the OPAL detector at centre-of-mass energies near the Z0 resonance. The measurement is based on two samples which identify one-prong tau decays with KL and KS mesons. The combined branching ratios are measured to be B(tau- -->pi- K0bar nutau) = (9.33+-0.68+-0.49)x10^-3 B(tau- -->pi- K0bar [>=1pi0] nutau) = (3.24+-0.74+-0.66)x10^-3 B(tau- -->K- K0bar [>=0pi0] nutau) = (3.30+-0.55+-0.39)x10^-3 where the first error is statistical and the second systematic.
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.
Autoresonant soliton and decay pumping
O. M. Kiselev
2013-01-29T23:59:59.000Z
The primary resonance equation in partial derivatives with external force and slowly varying frequency is derived. The leading-order term of asymptotic solution is constructed as a soliton with growing amplitude when time is large. This growing solution is obtained due to the decaying amplitude of the external force. A necessary condition for the growth of the solution in dissipative media is obtained also.
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.
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.
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.
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.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Beattie, M.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duperrin, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, V. N.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hart, B.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Holzbauer, J.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Lamont, I.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martínez-Ortega, J.; Mason, N.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Ratoff, P. N.; Razumov, I.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verkheev, A. Y.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vilanova, D.; Vokac, P.; Wahl, H. D.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Williams, M. R. J.; Wilson, G. W.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yang, S.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.; Yin, H.; Yip, K.; Youn, S. W.
2013-06-01T23:59:59.000Z
We present a measurement of the direct CP-violating charge asymmetry in B± mesons decaying to J/?K± and J/??± where J/? decays to ?+??, using the full run II data set of 10.4??fb?1 of proton-antiproton collisions collected using the D0 detector at the Fermilab Tevatron Collider. A difference in the yield of B? and B+ mesons in these decays is found by fitting to the difference between their reconstructed invariant mass distributions resulting in asymmetries of AJ/?K=[0.59±0.37]%, which is the most precise measurement to date, and AJ/??=[?4.2±4.5]%. Both measurements are consistent with standard model predictions.
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.
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 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.
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^+\
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).
Dental Decay Among Texas School Children.
Whitacre, Jessie (Jessie Opal)
1934-01-01T23:59:59.000Z
more often found ama older than the younger ones. With all children the numb( ing decayed 6-year molars increased rapidly with age up or 14 years. lightly more girls than boys in each race had decayed tee 'he data secured in this study suggest a... to Caries i vith Other Recent Studies I AcknowIedgm Summary Literature Ci ents -_---. ted -------- CTIN NO. 491 AUGUST, 1934 DENTAL DECAY AMONG TEXAS SCHOOL CHILDREN* sometix extensi Seve: aualifif agcum someti] diet (6 to curl...
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...
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.
N. L. Achouri; F. de Oliveira Santos; M. Lewitowicz; B. Blank; J. Aysto; G. Canchel; S. Czajkowski; P. Dendooven; A. Emsallem; J. Giovinazzo; N. Guillet; A. Jokinen; A. M. Laird; C. Longour; K. Perajarvi; N. Smirnova; M. Stanoiu; J. C. Thomas
2006-08-01T23:59:59.000Z
In an experiment performed at the LISE3 facility of GANIL, we studied the decay of 22Al produced by the fragmentation of a 36Ar primary beam. A beta-decay half-life of 91.1 +- 0.5 ms was measured. The beta-delayed one- and two-proton emission as well as beta-alpha and beta-delayed gamma decays were measured and allowed us to establish a partial decay scheme for this nucleus. New levels were determined in the daughter nucleus 22Mg. The comparison with model calculations strongly favours a spin-parity of 4+ for the ground state of 22Al.
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.
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_{\
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.
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...
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\
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.
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.
New expectations and uncertainties on Neutrinoless Double Beta Decay
Dell'Oro, Stefano; Vissani, Francesco
2014-01-01T23:59:59.000Z
The discovery of neutrino oscillations and its implication that neutrinos have mass have boosted the importance of neutrinoless double beta decay. Neutrinoless double beta decay offers unique chances to investigate the nature of the neutrino mass term, giving also information on the absolute scale and the mass hierarchy, assuming that neutrinos are Majorana particles. We study the Majorana Effective Mass, i. e. the crucial parameter that regulates the rate of the neutrinoless double beta decay due to light neutrino exchange. We update the previous estimations of this parameter, using the most recent data analysis, phase space factors and nuclear matrix elements. We evaluate the impact of the quenching in the nuclear medium of the axial vector coupling constant, as discussed by Iachello and collaborators. We provide estimations of the sensitivity of recent and future neutrinoless double beta decay experiments in terms of the Majorana Effective Mass. Finally, we discuss the possibility of taking advantage of th...
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.
Spectroscopy and decays of charm and bottom
Butler, J.N.
1997-10-01T23:59:59.000Z
After a brief review of the quark model, we discuss our present knowledge of the spectroscopy of charm and bottom mesons and baryons. We go on to review the lifetimes, semileptonic, and purely leptonic decays of these particles. We conclude with a brief discussion B and D mixing and rare decays.
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
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.
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.
auger decay spectra: Topics by E-print Network
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2008-01-01 44 Constraining Mass Spectra with Sterile Neutrinos from Neutrinoless Double Beta Decay, Tritium Beta Decay and Cosmology HEP - Experiment (arXiv) Summary: We...
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The strong decays of K1 resonances
Andrey Tayduganov; Emi Kou; Alain Le Yaouanc
2011-11-27T23:59:59.000Z
We investigate the K1--> K pi pi strong interaction decays. Using the 3P0 quark-pair-creation model to derive the basic parametrization, we discuss in detail how to obtain the various partial wave amplitudes into the possible quasi-two-body decay channels as well as their relative phases from the currently available experimental data. We obtain the K1 mixing angle to be thetaK1= 60 deg, in agreement with previous works. Our study can be applied to extract the information needed for the photon polarization determination of the radiative B--> K1 gamma decay.
Alpha decay chains from element 113
P. Roy Chowdhury; D. N. Basu; C. Samanta
2007-04-30T23:59:59.000Z
Theoretical estimates of $\\alpha$-decay half lives of several nuclei in the decay from element 113 are presented. Calculations in a WKB framework using DDM3Y interaction and experimental Q-values are in good agreement with the experimental data. Half life calculations are found to be quite sensitive to the Q-values and angular momenta transfers. Calculated decay lifetime decreases, owing to more penetrability as well as thinner barrier, as Q-value increases. Deviations to this predominant behaviour observed in some recent experimental data may be attributed to non zero spin-parities in some cases.
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.
N. Patronis; H. De Witte; M. Gorska; M. Huyse; K. Kruglov; D. Pauwels; K. Van de Vel; P. Van Duppen; J. Van Roosbroeck; J. -C. Thomas; S. Franchoo; J. Cederkall; V. N. Fedoseyev; H. Fynbo; U. Georg; O. Jonsson; U. Köster; T. Materna; L. Mathieu; O. Serot; L. Weissman; W. F. Mueller; V. I. Mishin; D. Fedorov
2009-09-01T23:59:59.000Z
A beta-decay study of Cu-77 has been performed at the ISOLDE mass separator with the aim to deduce its beta-decay properties and to obtain spectroscopic information on Zn-77. Neutron-rich copper isotopes were produced by means of proton- or neutron-induced fission reactions on U-238. After the production, Cu-77 was selectively laser ionized, mass separated and sent to different detection systems where beta-gamma and beta-n coincidence data were collected. We report on the deduced half-live, decay scheme, and possible spin assignment of 77Cu.
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.
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.
Interacting Dark Energy: Decay into Fermions
A. de la Macorra
2007-02-08T23:59:59.000Z
A dark energy component is responsible for the present stage of acceleration of our universe. If no fine tuning is assumed on the dark energy potential then it will end up dominating the universe at late times and the universe will not stop this stage of acceleration. On the other hand, the equation of state of dark energy seems to be smaller than -1 as suggested by the cosmological data. We take this as an indication that dark energy does indeed interact with another fluid (we consider fermion fields) and we determine the interaction through the cosmological data and extrapolate it into the future. We study the conditions under which a dark energy can dilute faster or decay into the fermion fields. We show that it is possible to live now in an accelerating epoch dominated by the dark energy and without introducing any fine tuning parameters the dark energy can either dilute faster or decaying into fermions in the future. The acceleration of the universe will then cease.
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.
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 ...
The BNL rare kaon decay program
Littenberg, L.
1996-12-31T23:59:59.000Z
The rare kaon decay program at Brookhaven National Laboratory is reviewed. Results from the last round of experiments are briefly discussed. The three experiments currently collecting data are described. Prospects for future experiments are discussed.
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.
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 $\
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.
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.
Electrical Analogs of Atomic Radiative Decay Processes
Fontana, Peter R.; Srivastava, Rajendra P.
1977-03-01T23:59:59.000Z
Simple electrical circuits are analyzed, and the results show that for high frequencies they have frequency and time responses identical to the spontaneous radiative decays of atoms. As an illustration of the analogy a two-circuit electrical system...
New Physics Effects From B Meson Decays
Anirban Kundu
2000-03-23T23:59:59.000Z
In this talk, we point out some of the present and future possible signatures of physics beyond the Standard Model from B-meson decays, taking R-parity conserving and violating supersymmetry as illustrative examples.
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.
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
Vacuum decay in a soluble model
Ferraz de Camargo F, A.; Shellard, R.C.; Marques, G.C.
1984-03-15T23:59:59.000Z
We study a field-theoretical model where the decay rate of the false vacuum can be computed up to the first quantum corrections in both the high-temperature and zero-temperature limits. We find that the dependence of the decay rate on the height and width of the potential barrier does not follow the same simple area rule as in the quantum-mechanical case. Furthermore, its behavior is strongly model dependent.
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.
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.
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
Ratios of heavy hadron semileptonic decay rates
Michael Gronau; Jonathan L. Rosner
2010-12-27T23:59:59.000Z
Ratios of charmed meson and baryon semileptonic decay rates appear to be satisfactorily described by considering only the lowest-lying (S-wave) hadronic final states and assuming the kinematic factor describing phase space suppression is the same as that for free quarks. For example, the rate for $D_s$ semileptonic decay is known to be $(17.0 \\pm 5.3)%$ lower than those for $D^0$ or $D^+$, and the model accounts for this difference. When applied to hadrons containing $b$ quarks, this method implies that the $B_s$ semileptonic decay rate is about 1% higher than that of the nonstrange $B$ mesons. This small difference thus suggests surprisingly good local quark-hadron duality for $B$ semileptonic decays, complementing the expectation based on inclusive quark-hadron duality that these differences in rates should not exceed a few tenths of a percent. For $\\Lambda_b$ semileptonic decay, however, the inclusive rate is predicted to be about 13% greater than that of the nonstrange $B$ mesons. This value, representing a considerable departure from a calculation using a heavy quark expansion, is close to the corresponding experimental ratio $\\Gamma(\\Lambda_b)/ \\bar \\Gamma(B) = 1.13 \\pm 0.03$ of total decay rates.
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.
DRAM Decay: Using Decay Counters to Reduce Energy Consumption in DRAMs
Lee, Hsien-Hsin "Sean"
DRAM Decay: Using Decay Counters to Reduce Energy Consumption in DRAMs Mrinmoy Ghosh Hsien-Hsin S. Lee School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta, GA 30332 technology they use. For each refresh in a DRAM row, the stored information in each cell is read out
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.
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.
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.
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.
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.
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.
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.
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.
Simulated progress in double-beta decay
Miley, H.S.; Arthur, R.J. [Pacific Northwest Lab., Richland, WA (United States); Avignone, F.T. [South Carolina Univ., Columbia, SC (United States)] [and others
1993-09-01T23:59:59.000Z
A Monte Carlo code has been developed to accurately simulate double-beta decay measurements. Coincident gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete {sup 100}Mo nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra obtained in the Homestake gold mine in Lead, SD, for the purpose of extremely sensitive materials assay for the construction of new, large, enriched germanium detectors. Assays as low as 9 {mu}Bq/g of {sup 210}Pb in lead shielding were obtained.
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)$.
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.
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.
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.
SU(3) Sum Rules for Charm Decay
Yuval Grossman; Dean J Robinson
2012-11-14T23:59:59.000Z
We present flavor SU(3) sum rules for $D \\to PP$ and $D \\to PV$ decay amplitudes, that are valid to second order in symmetry breaking by the strange quark mass spurion. Decay rate sum rules are also computed to this order. Particular attention is given to sum rules arising from the isospin and U-spin subgroups, the former providing sensitive tests for alternative sources of SU(3) breaking. We apply the latter together with the postulated $\\Delta U = 0$ rule for the large penguin picture to predict the ratio and difference of the direct CP asymmetries for $D \\to KK^*$ and $D \\to \\pi \\rho$.
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.
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.
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.
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.
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.
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\
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.
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
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).
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, ...
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.
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.
?-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.
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.
A Search for Neutrinoless Double Beta Decay of Te-130
Bryant, Adam Douglas
2010-01-01T23:59:59.000Z
Decay of Te by Adam Douglas Bryant A dissertation submitted2010 by Adam Douglas Bryant Te Abstract A Search forDecay of Te by Adam Douglas Bryant Doctor of Philosophy in
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?
Comparing radiative and recoil corrections in neutron beta-decay and inverse beta-decay
U. Raha; F. Myhrer; K. Kubodera
2014-05-06T23:59:59.000Z
The inverse $\\beta$-decay reaction, anti-nu_e + p --> e^+ + n, for low-energy anti-neutrinos coming from nuclear reactors is of great current interest in connection with high-precision measurements of the neutrino mixing angle $\\theta_{13}$. We have previously derived analytic expressions, up to next-to-leading order in heavy-baryon chiral perturbation theory, for the radiative corrections (RCs) and the nucleon-recoil corrections both for this reaction and for the related neutron $\\beta$-decay process. We investigate here the numerical consequences of these analytic expressions. We show that the recoil corrections are small for neutron $\\beta$-decay, but for inverse $\\beta$-decay, the recoil corrections are comparable in size to the RCs for typical energies of reactor anti-neutrinos, and they have opposite signs. It turns out that the RCs and the recoil corrections exhibit very different dependences on the neutrino energy.
{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.
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....
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.
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
DECAY CONSTANTS OF CHARGED PSEUDO-SCALAR MESONS
- and D+ s decays, the existence of a charged Higgs boson (or any other charged object beyond the Standard
Double Beta Decay Experiments Department of Physics and Astronomy
Piepke, Andreas G.
1 Double Beta Decay Experiments A. Piepkea a Department of Physics and Astronomy University. The experimen- tal investigation of the nuclear double beta decay is one of the key techniques for solving, such as the evaluation of the beta spec- tra near their endpoint, or neutrinoless double beta decay. The latter technique
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
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 .
Imperfect World of $\\beta\\beta$-decay Nuclear Data Sets
Pritychenko, B
2015-01-01T23:59:59.000Z
The precision of double-beta ($\\beta\\beta$) decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for $\\beta\\beta$-decay T$_{1/2}^{2\
Search for Invisibly Decaying Higgs Bosons with Large Decay Width Using the OPAL Detector at LEP
Abbiendi, G; Åkesson, P F; Alexander, G; Anagnostou, G; Anderson, K J; Asai, S; Axen, D; Bailey, I; Barberio, E; Barillari, T; Barlow, R J; Batley, J Richard; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, Siegfried; Biebel, O; Boeriu, O; Bock, P; Boutemeur, M; Braibant, S; Brown, R M; Burckhart, H J; Campana, S; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Ciocca, C; Csilling, A; Cuani, M; Dado, S; de Roeck, A; De Wolf, E A; Desch, K; Dienes, B; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, F; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Gagnon, P; Gary, J W; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Grunhaus, J; Gruwé, M; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harel, A; Hauschild, M; Hawkes, C M; Hawkings, R; Herten, G; Heuer, R D; Hill, J C; Horváth, D; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jovanovic, P; Junk, T R; Kanzaki, J; Karlen, D; Kawagoe, K; Kawamoto, T; Keeler, R K; Kellogg, R G; Kennedy, B W; Kluth, S; Kobayashi, T; Kobel, M; Komamiya, S; Kramer, T; Krasznahorkay, A; Krieger, P; Von Krogh, J; Kühl, T; Kupper, M; Laerty, G D; Landsman, H; Lanske, D; Lellouch, D; Letts, J; Levinson, L; Lillich, J; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, A; Ludwig, J; Mader, W; Marcellini, S; Martin, A J; Mashimo, T; Mättig, P; McKenna, J; McPherson, R A; Meijers, F; Menges, W; Merritt, F S; Mes, H; Meyer, N; Michelini, A; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; Nisius, R; O'Neale, S W; Oh, A; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Pilcher, J E; Pinfold, J L; Plane, D E; Pooth, O; Przybycien, M B; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Roney, J M; Rossi, A M; Rozen, Y; Runge, K; Sachs, K; Saeki, T; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Schar-Hansen, P; Schieck, J; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Seuster, R; Shears, T G; Shen, B C; Sherwood, P; Skuja, A; Smith, A M; Sobie, R J; Söldner-Rembold, S; Spanó, F; Stahl, A; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Tran, P; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vollmer, C F; Vannerem, P; Vertesi, R; Verzocchi, M; Voss, H; Vossebeld, Joost Herman; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wilson, G W; Wilson, J A; Wolf, G; Wyatt, T R; Yamashita, S; Zer-Zion, D; Zivkovic, L
2007-01-01T23:59:59.000Z
This paper describes a topological search for an invisibly decaying Higgs boson,H, produced via the Bjorken process (e+e- -> HZ). The analysis is based on data recorded using the OPAL detector at LEP at centre-of-mass energies from 183 to 209 GeV corresponding to a total integrated luminosity of 629pb-1. In the analysis only hadronic decays of the Z boson are considered. A scan over Higgs boson masses from 1 to 120 GeV and decay widths from 1 to 3000 GeV revealed no indication for a signal in the data. From a likelihood ratio of expected signal and Standard Model background we determine upper limits on cross-section times branching ratio to an invisible final state. For moderate Higgs boson decay widths, these range from about 0.07pb Mh = 60GeV) to 0.57pb (Mh = 114GeV). For decay widths above 200GeV the upper limits are of the order of 0.15pb. The results can be interpreted in general scenarios predicting a large invisible decay width of the Higgs boson. As an example we interpret the results in the so-called...
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.
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.
Effects of Light Scalar Mesons in eta -> 3pi decay
Abdou Abdel-Rehim; Deirdre Black; Amir H. Fariborz; Joseph Schechter
2002-10-01T23:59:59.000Z
We study the role of a possible nonet of light scalar mesons in the still interesting [eta] -> 3[p]i decay process, with the primary motivation of learning more about the scalars themselves. The framework is a conventional non-linear chiral Lagrangian of pseudoscalars and vectors extended to include the scalars. The parameters involving the scalars were previously obtained to fit the s-wave [pi][pi] and [pi] K scatterings in the region up to about 1 GeV as well as the strong decay [eta]' --> [eta][pi][pi]. At first, one might expect a large enhancement from diagrams including a light [sigma] (560). However there is an amusing cancellation mechanism which prevents this from occurring. In the simplest model there is an enhancement of about 13 per cent in the [eta] -> 3[pi] decay rate due to the scalars. In a more complicated model which includes derivative type symmetry breakers, the cancellation is modified and the scalars contribute about 30 percent of the total decay rate (although the total is not significantly changed). The vectors do not contribute much. Our model produces a reasonable estimate for the related a{sub 0}(980) - f{sub 0}(980) mixing strength, which has been a topic of current debate. Promising directions for future work along the present line are suggested.
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.
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.
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.
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.
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.
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.
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.
Analysis of exponential decay curves of mixtures
McGaughey, Robert Lee
1967-01-01T23:59:59.000Z
. Tommy Cobb who kept me on the straight and narrow during those first few trying weeks, and to Richard "Hoot" Gibson for his help with LP/90. TABLE OF CONTENTS Acknowledgments List of Tables CHAPTER Page lil Introduction III IV Linear... thesis written by Lt, Col. Tommy Cobb at Texas A&M University in the spring of 1966. When most substances are irradiated, radioactive isotopes are created which give off radioactive emissions according to the exponen- tial decay formula. The half...
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}<
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.
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.
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.
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.
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.
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.
Sensitivity of CUORE to Neutrinoless Double-Beta Decay
CUORE; Alessandria, F.; Andreotti, E.; Ardito, R.; Arnaboldi, C.; Avignone III, F. T.; Balata, M.; Bandac, I.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; Bloxham, T.; Brofferio, C.; Bryant, A.; Bucci, C.; Cai, X. Z.; Canonica, L.; Capelli, S.; Carbone, L.; Cardani, L.; Carrettoni, M.; Casali, N.; Chott, N.; Clemenza, M.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Dafinei, I.; Dally, A.; Biasi, A. De; Decowski, M. P.; Deninno, M. M.; Waard, A. de; Domizio, S. Di; Ejzak, L.; Faccini, R.; Fang, D. Q.; Farach, H. A.; Ferri, E.; Ferroni, F.; Fiorini, E.; Foggetta, L.; Franceschi, M. A.; Freedman, S. J.; Frossati, G.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gorla, P.; Gotti, C.; Guardincerri, E.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Heeger, K. M.; Huang, H. Z.; Ichimura, K.; Kadel, R.; Kazkaz, K.; Keppel, G.; Kogler, L.; Kolomensky, Yu. G.; Kraft, S.; Lenz, D.; Li, Y. L.; Liu, X.; Longo, E.; Ma, Y. G.; Maiano, C.; Maier, G.; Maino, M.; Mancini, C.; Martinez, C.; Martinez, M.; Maruyama, R. H.; Moggi, N.; Morganti, S.; Napolitano, T.; Newman, S.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; Orio, F.; Orlandi, D.; Ouellet, J. L.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Previtali, E.; Rampazzo, V.; Rimondi, F.; Rosenfeld, C.; Rusconi, C.; Salvioni, C.; Sangiorgio, S.; Schaeffer, D.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Stivanello, F.; Taffarello, L.; Terenziani, G.; Tian, W. D.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wang, B. S.; Wang, H. W.; Whitten Jr., C. A.; Wise, T.; Woodcraft, A.; Xu, N.; Zanotti, L.; Zarra, C.; Zhu, B. X.; Zucchelli, S.
2011-11-23T23:59:59.000Z
In this paper, we study the sensitivity of CUORE, a bolometric double-beta decay experiment under construction at the Laboratori Nazionali del Gran Sasso in Italy. Two approaches to the computation of experimental sensitivity are discussed and compared, and the formulas and parameters used in the sensitivity estimates are provided. Assuming a background rate of 10{sup -2} cts/(keV kg y), we find that, after 5 years of live time, CUORE will have a 1#27;{sigma} sensitivity to the neutrinoless double-beta decay half-life of {caret T{sup 0{nu}}{sub 1/2}}(1{sigma}#27;) = 1.6x#2;10{sup 26} y and thus a potential to probe the effective Majorana neutrino mass down to 41-95 meV; the sensitivity at 1.64{sigma}#27;, which corresponds to 90% C.L., will be {caret T{sup 0{nu}}{sub 1/2}(1.64{sigma}#27;}) = 9.5x10{sup 25} y. This range is compared with the claim of observation of neutrinoless double-beta decay in {sup 76}Ge and the preferred range in the neutrino mass parameter space from oscillation results.
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.
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.
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.
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...
Fission-product-decay characteristics. Master's thesis
Millage, K.K.
1989-03-01T23:59:59.000Z
This theses determined fission-product decay characteristics , including the total activity, the gamma-ray emission rate (GER) and gamma-ray energy spectra. The activity and GER decay were compared to Way and Wigner's t(exp(-1.2)) approximation, and the effects the spectra, activity, and GER have on the Source Normalization Constant (K) were examined. Most of the fission-product data were obtained from DKPOWR, and were compared with data obtained from ORIGIN2. Since the gamma rays are of primary concern in fallout studies, the GER is used instead of activity. The ratio of GER to activity changes significantly with time. Results of this study calculate a GER of 590 x 10/sup 16/ gamma rays/second per kT of fission yield from U-235 fuel and a K of 7059 R/Hr/(kT/sq.km.). The calculation of K includes the contribution from scattered photons. The GER result is 11% higher than reference values, while the K is within 2% of the current value in Glasstone and Dolan's The Effects of Nuclear Weapons. The Ks for Pu-239 and U-238 were within 5% of the U-235 results. The wax-wigners t(exp(-1.2)) approximation differs from time dependent GER and K up to 85% for times less than 6 months. The approximation is not valid for the GER or K at times greater than 6 months. The approximation is within about 45%, for the activity from fission-product decay to at least 5 years. A more accurate measure of exposure requires a numerical integration of the time dependent GER and Source Normalization Constant.
Electron shell and the alpha-decay
Sergey Yu. Igashov; Yury M. Tchuvil'sky
2012-12-03T23:59:59.000Z
The ratio of the alpha-decay widths of a bare nucleus and the related atom is calculated. Both the change of the form and thus the penetrability of the potential barrier and the effect of reflection in the classically-allowed region appearing due to the electron shell are taken into account in the calculations of this ratio. The contribution of each of these two effects is of one and the same order of magnitude. For long-lived radioactive samples the values of the total effect turn out to be somewhat below 1 percent.
Tunneling decay rate in quantum cosmology
Mithani, Audrey T
2015-01-01T23:59:59.000Z
In canonical quantum cosmology, the wave function of the universe lacks explicit time dependence. However, time evolution may be present implicitly through the semiclassical superspace variables, which themselves depend on time in classical dynamics. In this paper, we apply this approach to an oscillating universe model recently introduced by Graham et al. By extending the model to include a massless, minimally coupled scalar field $\\phi$ which has little effect on the dynamics but can play the role of a "clock", we determine the decay rate of the oscillating universe.
Tunneling decay rate in quantum cosmology
Audrey T. Mithani; Alexander Vilenkin
2015-03-02T23:59:59.000Z
In canonical quantum cosmology, the wave function of the universe lacks explicit time dependence. However, time evolution may be present implicitly through the semiclassical superspace variables, which themselves depend on time in classical dynamics. In this paper, we apply this approach to an oscillating universe model recently introduced by Graham et al. By extending the model to include a massless, minimally coupled scalar field $\\phi$ which has little effect on the dynamics but can play the role of a "clock", we determine the decay rate of the oscillating universe.
Rare b hadron decays at the LHC
Blake, T; Hiller, G
2015-01-01T23:59:59.000Z
With the completion of Run~I of the CERN Large Hadron Collider, particle physics has entered a new era. The production of unprecedented numbers of heavy-flavoured hadrons in high energy proton-proton collisions allows detailed studies of flavour-changing processes. The increasingly precise measurements allow to probe the Standard Model with a new level of accuracy. Rare $b$ hadron decays provide some of the most promising approaches for such tests, since there are several observables which can be cleanly interpreted from a theoretical viewpoint. In this article, the status and prospects in this field are reviewed, with a focus on precision measurements and null tests.
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.
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.
Results of the NEMO-3 Double Beta Decay Experiment
Mathieu BONGRAND for the NEMO-3 Collaboration
2011-05-12T23:59:59.000Z
The NEMO-3 experiment is searching for neutrinoless double beta decay for 2 main isotopes (100Mo and 82Se) and is studying the two-neutrino double beta decay of seven isotopes. The experiment has been taking data since 2003 and, up to the end of 2009, showed no evidence for neutrinoless double beta decay. Two 90 % CL lower limits on the half-lives of the transitions were obtained : T_{1/2}^{0\
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 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.
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...
Neutrino mass spectrum and neutrinoless double beta decay
H. V. Klapdor-Kleingrothaus; H. Päs; A. Y. Smirnov
2000-10-08T23:59:59.000Z
The relations between the effective Majorana mass of the electron neutrino, $m_{ee}$, responsible for neutrinoless double beta decay, and the neutrino oscillation parameters are considered. We show that for any specific oscillation pattern $m_{ee}$ can take any value (from zero to the existing upper bound) for normal mass hierarchy and it can have a minimum for inverse hierarchy. This means that oscillation experiments cannot fix in general $m_{ee}$. Mass ranges for $m_{ee}$ can be predicted in terms of oscillation parameters with additional assumptions about the level of degeneracy and the type of hierarchy of the neutrino mass spectrum. These predictions for $m_{ee}$ are systematically studied in the specific schemes of neutrino mass and flavor which explain the solar and atmospheric neutrino data. The contributions from individual mass eigenstates in terms of oscillation parameters have been quantified. We study the dependence of $m_{ee}$ on the non-oscillation parameters: the overall scale of the neutrino mass and the relative mass phases. We analyze how forthcoming oscillation experiments will improve the predictions for $m_{ee}$. On the basis of these studies we evaluate the discovery potential of future \\znbb decay searches. The role \\znbb decay searches will play in the reconstruction of the neutrino mass spectrum is clarified. The key scales of $m_{ee}$, which will lead to the discrimination among various schemes are: $m_{ee} \\sim 0.1$ eV and $m_{ee} \\sim 0.005$ eV.
About radiative kaon decay \\k+ \\to ?+\\pi0?
V. P. Efrosinin
2006-06-20T23:59:59.000Z
With usage of the Low theorem the general expression for amplitude of radiative kaon decay \\k+ \\to \\pi+\\pi0\\gamma is determined.
What can we learn from neutrinoless double beta decay experiments?
John N. Bahcall; Hitoshi Murayama; Carlos Pena-Garay
2004-04-08T23:59:59.000Z
We assess how well next generation neutrinoless double beta decay and normal neutrino beta decay experiments can answer four fundamental questions. 1) If neutrinoless double beta decay searches do not detect a signal, and if the spectrum is known to be inverted hierarchy, can we conclude that neutrinos are Dirac particles? 2) If neutrinoless double beta decay searches are negative and a next generation ordinary beta decay experiment detects the neutrino mass scale, can we conclude that neutrinos are Dirac particles? 3) If neutrinoless double beta decay is observed with a large neutrino mass element, what is the total mass in neutrinos? 4) If neutrinoless double beta decay is observed but next generation beta decay searches for a neutrino mass only set a mass upper limit, can we establish whether the mass hierarchy is normal or inverted? We base our answers on the expected performance of next generation neutrinoless double beta decay experiments and on simulations of the accuracy of calculations of nuclear matrix elements.
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.
Decay of Solutions to Viscous asymptotical models for waterwaves ...
2010-02-08T23:59:59.000Z
Global Science Preprint .... We plan to let ? ?0. We then apply the ... From the energy equality in the section above, it transpires that the solution decays to 0.
Mass Measurement Using Energy Spectra in Three-body Decays
Kaustubh Agashe; Roberto Franceschini; Doojin Kim; Kyle Wardlow
2015-03-12T23:59:59.000Z
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 indistinguishable visible final states on both decay sides can be treated by an "event mixing" technique, the performance of which is discussed in detail. Taking into account dominant backgrounds, we are able to show that the mass of the gluino and, in favorable cases, that of the neutralino can be determined by this mass measurement strategy.
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.
Neutrinoless Double Beta Decay within QRPA with Proton-Neutron Pairing
G. Pantis; F. Simkovic; J. D. Vergados; Amand Faessler
1996-12-14T23:59:59.000Z
We have investigated the role of proton-neutron pairing in the context of the Quasiparticle Random Phase approximation formalism. This way the neutrinoless double beta decay matrix elements of the experimentally interesting A= 48, 76, 82, 96, 100, 116, 128, 130 and 136 systems have been calculated. We have found that the inclusion of proton-neutron pairing influences the neutrinoless double beta decay rates significantly, in all cases allowing for larger values of the expectation value of light neutrino masses. Using the best presently available experimental limits on the half life-time of neutrinoless double beta decay we have extracted the limits on lepton number violating parameters.
Bs-->K+K- and Bs-->K0 anti-K0 Decays within Supersymmetry
Seungwon Baek; David London; Joaquim Matias; Javier Virto
2006-11-27T23:59:59.000Z
We compute the supersymmetric (SUSY) contributions to the observables in Bs-->K+K- and Bs-->K0 anti-K0 decays. The hadronic parameters in the standard-model (SM) amplitudes are obtained from the Bd-->K0 anti-K0 decay using a recent approach that combines flavor SU(3) symmetry and a controlled input from QCD factorization. The latest experimental data for BR(Bs-->K+K-) is in agreement with the SM prediction. We study how the branching ratios and the direct and mixing-induced CP asymmetries of both Bs-->KK decay modes are affected with the inclusion of SUSY, after imposing constraints from BR(B--> Xs gamma), B--> pi K and Delta Ms over the parameter space. While the branching ratios remain unaffected by SUSY, we identify the CP asymmetries of the Bs-->KK decays as the most promising observables to look for large deviations from the SM.
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.
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
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.
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.
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.
Seven surrogate precursors for modeling delayed neutron decay and predicting reactivity
Loaiza, D.J.; Haskin, F.E.
1997-12-31T23:59:59.000Z
The use of a different set of group decay constants for each fissionable nuclide complicates analysis of the dynamic behavior of fast reactors. A fast reactor containing six principal fissioning nuclides of uranium and plutonium must, in effect, be described by 36 delayed neutron groups. Additionally, the use of group decay constants that depend on the neutron energy spectrum makes it difficult to select values that describe the dynamic response of epithermal systems because virtually all delayed neutron activity measurements have been performed for fast or thermal-neutron-induced fission. Clearly, it would be desirable to have a single set of group decay constants that could be applied to all fissionable nuclides. A set of seven fixed decay constants is proposed herein. Each of the proposed decay constants is associated with a specific, dominant delayed neutron precursor. In effect, each group is represented by a single surrogate precursor. Using recently measured delayed neutron activities for U-235 and Np-237, the proposed set of decay constants actually improved the goodness of fit to the data. For other fissionable nuclides lacking experimental data, a method has been devised to obtain yields consistent with the proposed set of decay constants from the traditional six-group parameters. This transformation is accomplished without altering the traditional inferred reactivity scale.
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.).
Study of Bc->KK decay with perturbative QCD approach
Yue-Ling Yang; Jun-Feng Sun; Na Wang
2010-04-16T23:59:59.000Z
In the framework of the perturbative QCD approach, we study the charmless pure weak annihilation Bc->KK decay and find that the branching ratio BR(Bc->KK) O(10^-7). This prediction is so tiny that the Bc->KK decay might be unmeasurable at the Large Hadron Collider.
anisotropic decay dynamics: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
anisotropic decay dynamics First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Anisotropic decay dynamics...
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.
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.
SciTech Connect: Beta Decay of B12
Office of Scientific and Technical Information (OSTI)
Journal Article: Beta Decay of B12 Citation Details In-Document Search Title: Beta Decay of B12 The 3.23-Mev gamma-ray transition between the 7.66 and 4.43-Mev states of C12 has...
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.
Dalitz Analysis of Three-Body B Decays
A. Garmash; for the Belle Collaboration
2005-05-16T23:59:59.000Z
Results on Dalitz analysis of three-body charmless B+=>K+pi+pi- and B+=>K+K+K- decays are reported. We also present preliminary results on the studies of direct CP violation in three-body decay B+-=>K+-pi+pi-. The analysis is performed using a large data sample collected with the Belle detector.
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...
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.
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.
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.
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.
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,
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.
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
A search for two body muon decay signals
R. Bayes; J. Bueno; Yu. I. Davydov; P. Depommier; W. Faszer; M. C. Fujiwara; C. A. Gagliardi; A. Gaponenko; D. R. Gill; A. Grossheim; P. Gumplinger; M. D. Hasinoff; R. S. Henderson; A. Hillairet; J. Hu; D. D. Koetke; R. P. MacDonald; G. M. Marshall; E. L. Mathie; R. E. Mischke; K. Olchanski; A. Olin; R. Openshaw; J. -M. Poutissou; R. Poutissou; V. Selivanov; G. Sheffer; B. Shin; T. D. S. Stanislaus; R. Tacik; R. E. Tribble
2015-03-10T23:59:59.000Z
Lepton family number violation is tested by searching for $\\mu^+\\to e^+X^0$ decays among the 5.8$\\times 10^8$ positive muon decay events analyzed by the TWIST collaboration. Limits are set on the production of both massless and massive $X^0$ bosons. The large angular acceptance of this experiment allows limits to be placed on anisotropic $\\mu^+\\to e^+X^0$ decays, which can arise from interactions violating both lepton flavor and parity conservation. Branching ratio limits of order $10^{-5}$ are obtained for bosons with masses of 13 - 80 MeV/c$^2$ and with different decay asymmetries. For bosons with masses less than 13 MeV/c$^{2}$ the asymmetry dependence is much stronger and the 90% limit on the branching ratio varies up to $5.8 \\times 10^{-5}$. This is the first study that explicitly evaluates the limits for anisotropic two body muon decays.
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-
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.
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.
Nonsingular Decaying Vacuum Cosmology and Entropy Production
J. A. S. Lima; S. Basilakos; Joan Solà
2015-03-08T23:59:59.000Z
The thermodynamic behavior of a decaying vacuum cosmology describing the entire cosmological history evolving between two extreme (early and late time) de Sitter eras is investigated. The thermal evolution from the early de Sitter to the radiation phase is discussed in detail. The temperature evolution law and the increasing entropy function are analytically determined. The entropy of the effectively massless particles is initially zero but evolves continuously to the present day maximum value within the current Hubble radius, $S_0 \\sim 10^{88}$ in natural units. By using the Gibbons-Hawking temperature relation for the de Sitter spacetime, it is found that the ratio between the primeval and the late time vacuum energy densities is $\\rho_{vI}/\\rho_{v0} \\sim 10^{123}$, as required by some naive estimates from quantum field theory.
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.
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.
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.
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.
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 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.
The First Estimates of Kinematically Forbidden D Meson Decays
Verma, R C; Odagiri, Kosuke
2015-01-01T23:59:59.000Z
The weak hadronic decay D^+ -> K^0\\bar a_1^+ is kinematically forbidden at the peak mass values of the particles involved. However, occurrence of this decay has been reported with branching fraction (9.1 \\plusminus 1.8) \\cross 10^{-3} in the analysis of D^+ -> K^\\bar0 4 \\pi decay data. This is due to smearing effects on this decay caused mainly by the large width of a_1-resonance, which extends the phase space and allows this decay. Using a factorization model to evaluate decay amplitudes for external and internal W-emission diagrams, and incorporating Breit-Wigner smearing using the total a_1 width of 400 MeV, we obtain the first estimate for branching fraction of this decay to be 3.3 \\cross 10^{-3} and 7.0 \\cross 10^{-3}, for |V_1^{Da1} (0)|=0.40 and 1.50 respectively corresponding to different theoretical models, where |V_1^{Da1} (q^2)| is the vector form factor appearing in the D -> a_1 s-wave transition. The estimates are of the desired order of magnitude. We also predict branching fractions of its count...
Radiative Decays of the B Meson
Tanaka, Hirohisa A
2003-09-23T23:59:59.000Z
The radiative decays of the B meson to the final states K *(892){gamma} and {rho}(770){gamma} proceed through virtual effective flavor-changing neutral current processes which are sensitive to contributions from high mass scales from within the Standard Model of particle interactions and from possible new physics. In the context of the Standard Model, these transitions are of interest in probing the weak interaction behavior of the top quark. In particular, the ratio of branching fractions for the two processes can be used to extract the ratio of Cabibbo-Kobayashi-Maskawa matrix elements |V{sub td}/V{sub ts}|. Potential new physics contributions in these virtual transitions may induce new sources of direct CP violation and enhancement or suppression of the rate of these processes. The B {yields} K*{gamma} is a manifestation of the b {yields} s{gamma} radiative transition. This process has been previously observed by the CLEO collaboration and its branching fraction measured. While the theoretical prediction for the inclusive rate of b {yields} s{gamma} transitions is more robust than that of the exclusive B {yields} K*{gamma}, the prospects for precise measurements of {Beta}[B {yields} K*{gamma}] and direct CP violation in this channel has attracted considerable attention. The analysis described here represents an improved measurement of the B {yields} K*{gamma} branching factions and a more sensitive search for direct CP violation. In 22.7 x 10{sup 6} B{bar B} events collected by the BABAR detector in 1999-2000, we measure: {Beta}[B{sup 0} {yields} K*{sup 0}{gamma}] = 4.23 {+-} 0.40(stat.) {+-} 0.22(syst.) x 10{sup -5} and {Beta}[B{sup +} {yields} K*{sup +}{gamma}] = 3.83 {+-} 0.62(stat.) {+-} 0.22(syst.) x 10{sup -5}. We find no evidence for direct CP violation in the decays and constrain -0.170 < A{sub CP} < 0.082 at 90% Confidence Level. The B {yields} {rho}{gamma} proceeds through the analogous b {yields} d{gamma} radiative transition. As such, its rate is suppressed by a factor of |V{sub td}/V{sub ts}|{sup 2} {approx} {Omicron}(50) relative to B {yields} K*{gamma} and remains unobserved. Current limits on the branching fractions of B {yields} {rho}{gamma} are still an order of magnitude above the theoretical predictions. While the uncertainty in the theoretical predictions for the branching fraction of this mode are large, it may be possible to reduce these uncertainties by considering the ratio of the branching fractions for B {yields} {rho}{gamma} and B {yields} K*{gamma} which would lead to a measurement of |V{sub td}/V{sub ts}|. The analysis presented here represents a search with nearly an order of magnitude more data and new analysis techniques. In a sample of 61 .7 x 10{sup 6} B{bar B} events, we find no significant evidence for the decay B {yields} {rho}{gamma} is and establish the following 90% Confidence Level upper limits on the branching fraction: {Beta}[B{sup 0} {yields} {rho}{sup 0}{gamma}] < 1.5 x 10{sup -6} and {Beta}[B{sup +} {yields} {rho}{sup +}{gamma}] < 2.8 x 10{sup -6}.
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.
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.
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.
T violation in radiative $\\beta$ decay and electric dipole moments
Dekens, W G
2015-01-01T23:59:59.000Z
In radiative $\\beta$ decay, $T$ violation can be studied through a spin-independent $T$-odd correlation. We consider contributions to this correlation by beyond the standard model (BSM) sources of $T$-violation, arising above the electroweak scale. At the same time such sources, parametrized by dimension-6 operators, can induce electric dipole moments (EDMs). As a consequence, the manifestations of the $T$-odd BSM physics in radiative $\\beta$ decay and EDMs are not independent. Here we exploit this connection to show that current EDM bounds already strongly constrain the spin-independent $T$-odd correlation in radiative $\\beta$ decay.
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}.
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.
Sensitivity Increases for the TITAN Decay Spectroscopy Program
K. G. Leach; A. Lennarz; A. Grossheim; C. Andreoiu; J. Dilling; D. Frekers; M. Good; S. Seeraji
2014-10-30T23:59:59.000Z
The TITAN facility at TRIUMF has recently initiated a program of performing decay spectroscopy measurements in an electron-beam ion-trap (EBIT). The unique environment of the EBIT provides backing-free storage of the radioactive ions, while guiding charged decay particles from the trap centre via the strong magnetic field. This measurement technique is able to provide a significant increase in detection sensitivity for photons which result from radioactive decay. A brief overview of this device is presented, along with methods of improving the signal-to-background ratio for photon detection by reducing Compton scattered events, and eliminating vibrational noise.
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.
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.
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.
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.
Observation of New Charmless Decays of Bottom Hadrons
Xie, Si
We search for new charmless decays of neutral b hadrons to pairs of charged hadrons, using 1??fb[superscript -1] of data collected by the CDF II detector at the Fermilab Tevatron. We report the first observation of the ...
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.
Double beta decay experiments: past and present achievements
Alexander Barabash
2006-08-23T23:59:59.000Z
A brief history of double beta decay experiments is presented. The best currently running experiments (NEMO-3 and CUORICINO) and their latest results are described. The best measurements and limits for the $2\
Double Beta Decay: Historical Review of 75 Years of Research
A. S. Barabash
2011-04-25T23:59:59.000Z
Main achievements during 75 years of research on double beta decay have been reviewed. The existing experimental data have been presented and the capabilities of the next-generation detectors have been demonstrated.
Observations of Electrons from the Decay of Solar Flare Neutrons
W. Dröge; D. Ruffolo; B. Klecker
1996-04-03T23:59:59.000Z
We have found evidence for fluxes of energetic electrons in interplanetary space on board the ISEE-3 spacecraft which we interpret as the decay products of neutrons generated in a solar flare on 1980 June 21. The decay electrons arrived at the s/c shortly before the electrons from the flare and can be distinguished from the latter by their distinctive energy spectrum. The time profile of the decay electrons is in good agreement with the results from a simulation based on a scattering mean free path derived from a fit to the flare electron data. The comparison with simultaneously observed decay protons and a published direct measurement of high-energy neutrons places important constraints on the parent neutron spectrum.
Ultra High Energy Cosmic Rays from Decaying Superheavy Particles
V. Berezinsky
1998-01-08T23:59:59.000Z
Decaying superheavy particles can be produced by Topological Defects or, in case they are quasi-stable, as relics from the early Universe. The decays of these particles can be the sources of observed Ultra High Energy Cosmic Rays ($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.
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...
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
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.
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, ...
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.
alpha decay chains: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Das; G. Gangopadhyay 2004-03-12 46 Alpha Backgrounds for HPGe Detectors in Neutrinoless Double-Beta Decay Experiments Nuclear Experiment (arXiv) Summary: The Majorana Experiment...
Lepton flavor violation decays with the fourth generation neutrino
Wu-Jun Huo; Tai-Fu Feng
2002-03-22T23:59:59.000Z
We investigate the lepton flavor violation decays, $\\tau \\to \\mu\\gamma$, $\\tau \\to e\\gamma$ and $\\mu \\to e\\gamma$, in the framwork of a squential fourth generation model with a heavy fourth neutrino, $\
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.
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.
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.
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.
{beta}-delayed neutron decay of {sup 14}Be
Belbot, M.D.; Kolata, J.J.; Lamkin, K.; Tighe, R.J.; Zahar, M. [Physics Department, University of Notre Dame, Notre Dame, Indiana 46556 (United States)] [Physics Department, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Harkewicz, R.; Morrissey, D.J.; Orr, N.A.; Ronningen, R.M.; Sherrill, B.M.; Winger, J.A. [Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)] [Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Carpenter, M. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
1995-05-01T23:59:59.000Z
The neutron spectroscopy of the {beta}-delayed neutron decay of {sup 14}Be has been investigated. Two neutron groups were observed, and energy limits are given for a third (unobserved) group that receives most of the {beta}-decay strength. Branching ratios and log{ital ft} values deduced for all three groups are compared with the results of a shell-model calculation.
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.
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.
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.
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.
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.
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.
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.
Utrecht, Universiteit
between an activated and latent state results in the typical decelerating decay of virus load following
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.
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
Search for the CP symmetry violation in the decays of Ks mesons using the KLOE detector
M. Silarski
2013-02-19T23:59:59.000Z
The aim of this work was to determine the KS -> 3pi0 decay branching ratio and a modulus of the eta000 parameter, defined as the ratio of amplitudes for KS -> 3 pi0 to KL -> 3pi0 decays, which characterizes the CP symmetry violation in this decay. The measurement has been carried out with the KLOE detector operating at the phi-factory DAFNE in the Italian National Center for Nuclear Physics in Frascati. The KS mesons were identified with high efficiency via registration of these KL mesons which crossed the drift chamber without decaying and then interacted with the KLOE electromagnetic calorimeter. The KS four-momentum vector was then determined using the registered position of the KL meson and the known momentum of the phi meson. Next, the search for the KS -> 3pi0 -> 6gamma decay was carried out by the selection of events with six gamma quanta which momenta were reconstructed using time and energy measured by the electromagnetic calorimeter. To increase the signal over background ratio after identification of the KS meson and requiring six reconstructed photons a discriminant analysis is performed. It is based on kinematical fit, testing of the signal and background hypotheses and exploiting of the differences in kinematics of the KS decays into 2pi0 and 3pi0. Hence, we have obtained the upper limit on the KS -> 3pi0 branching ratio at the 90% confidence level BR(KS -> 3pi0)KS -> 3pi0 decay presented in this work failed to detect a signal of sufficient statistical significance. This upper limit can be translated into a limit on the modulus of the eta000 parameter amounting to: |eta000| < 0.009 at the 90% confidence level.
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 $S^- = 0.025 \\pm 0.041 ({\\rm stat}) \\pm 0.018 ({\\rm syst})$.
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.
Precision muon decay measurements and improved constraints on the weak interaction
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Hillairet, A.; Bayes, R.; Bueno, J. F.; Davydov, Yu. I.; Depommier, P.; Faszer, W.; Gagliardi, C. A.; Gaponenko, A.; Gill, D. R.; Grossheim, A.; Gumplinger, P.; Hasinoff, M. D.; Henderson, R. S.; Hu, J.; Koetke, D. D.; MacDonald, R. P.; Marshall, G. M.; Mathie, E. L.; Mischke, R. E.; Olchanski, K.; Olin, A.; Openshaw, R.; Poutissou, J.-M.; Poutissou, R.; Selivanov, V.; Sheffer, G.; Shin, B.; Stanislaus, T. D. S.; Tacik, R.; Tribble, R. E.; TWIST Collaboration
2012-05-01T23:59:59.000Z
The TWIST Collaboration has completed its measurement of the three muon decay parameters ? , ? , and P? ? . This paper describes our determination of ? , which governs the shape of the overall momentum spectrum, and ? , which controls the momentum dependence of the parity-violating decay asymmetry. The results are ?=0.749?77±0.000?12(stat)±0.000?23(syst) and ?=0.750?49±0.000?21(stat)±0.000?27(syst) . These are consistent with the value of 3/4 given for both parameters in the standard model, and each is over a factor of 10 more precise than the measurements published prior to TWIST. Our final results on ? , ? , and P? ? have been incorporated into a new global analysis of all available muon decay data, resulting in improved model-independent constraints on the possible weak interactions of right-handed particles.
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.
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.
Prospects for future experiments to search for nucleon decay
Ayres, D.S.; Heller, K.; LoSecco, J.; Mann, A.K.; Marciano, W.; Shrock, R.E.; Thornton, R.K.
1982-01-01T23:59:59.000Z
We review the status of theoretical expectations and experimental searches for nucleon decay, and predict the sensitivities which could be reached by future experiments. For the immediate future, we concur with the conclusions of the 1982 Summer Workshop on Proton Decay Experiments: all detectors now in operation or construction will be relatively insensitive to some potentially important decay modes. Next-generation experiments must therefore be designed to search for these modes, and should be undertaken whether or not present experiments detect nucleon decay in other modes. These future experiments should be designed to push the lifetime limits on all decay modes to the levels at which irreducible cosmic-ray neutrino-induced backgrounds become important. Since the technology for these next-generation experiments is available now, the timetable for starting work on them will be determined by funding constraints and not by the need for extensive development of detectors. Efforts to develop advanced detector techniques should also be pursued, in order to mount more sensitive searches than can be envisioned using current technology, or to provide the most precise measurements possible of the properties of the nucleon decay interaction if it should occur at a detectable rate.
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.
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)%.
$?$-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.
First observation of /sup 162/Hf decay completion of an alpha -decay chain
Schrewe, U J; Hagberg, E; Hardy, J C; Koslowsky, V T; Schmeing, H; Sharma, K S
1981-01-01T23:59:59.000Z
The new isotope /sup 162/Hf (T/sub 1/2/=(37.6+or-0.8)s) is produced in a /sup 142/Nd (/sup 24/Mg,4n) reaction. The activities produced in this reaction are transported to a measuring station by use of a He- jet system. Decay properties are observed with alpha -, gamma -, and gamma - gamma -spectroscopy. The Z-assignment of the new isotope is based on a cross bombardment on /sup 141/Pr target and on the results of a gamma -X-ray coincidence measurement. The mass assignment is deduced from the excitation function measurements. From the measured alpha -decay energy E/sub alpha /=4308 (10) keV new mass values are derived for /sup 162/Hf, /sup 166/W, /sup 170/Os, /sup 174/Pt, and /sup 178/Hg. These new mass values make it possible to establish systematics of two-proton and one-proton binding energies far from stability. (20 refs).
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.
Neutrino oscillation constraints on neutrinoless double beta decay
S. M. Bilenky; C. Giunti; C. W. Kim; M. Monteno
1997-11-20T23:59:59.000Z
We have studied the constraints imposed by the results of neutrino oscillation experiments on the effective Majorana mass || that characterizes the contribution of Majorana neutrino masses to the matrix element of neutrinoless double-beta decay. We have shown that in a general scheme with three Majorana neutrinos and a hierarchy of neutrino masses (which can be explained by the see-saw mechanism), the results of neutrino oscillation experiments imply rather strong constraints on the parameter ||. From the results of the first reactor long-baseline experiment CHOOZ and the Bugey experiment it follows that || | > 10^{-1} eV would be a signal for a non-hierarchical neutrino mass spectrum and/or non-standard mechanisms of lepton number violation.
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 ...
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
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\
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\
Bao-Quan Ou; Lin-Mei Liang; Cheng-Zu Li
2007-12-25T23:59:59.000Z
Following the method of Victor V. Kozlov et al.[PhysRevA. 74. 063829],we inspect the coherence induced by incoherent pump and spontaneous decay process in $\\Lambda$ type three-level atomic system with degenerated lower duplicate levels. The system shows a coherent population trapping state and multi-steady states characteristic in different conditions. Interestingly, two kinds of steady states generated by the system in different sets of pumping and decaying parameters, the "singlet" state and the "triplet" state, exhibit stable or unstable characteristics under the action of pumping field and vacuum reservoir, which promise fruitful applications to atomic coherence and interference in quantum optics.
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.
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...
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.
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.
Beta decay of Neutron-Rich 53-56Ca
P. F. Mantica; R. Broda; H. L. Crawford; A. Damaske; B. Fornal; A. A. Hecht; C. Hoffman; M. Horoi; N. Hoteling; R. V. F. Janssens; J. Pereira; J. S. Pinter; J. B. Stoker; S. L. Tabor; T. Sumikama; W. B. Walters; X. Wang; S. Zhu
2008-01-07T23:59:59.000Z
Beta-decay properties of neutron-rich Ca isotopes have been obtained. Half-life values were determined for the first time for 54Ca [86(7) ms], 55Ca [22(2) ms], and 56Ca [11(2) ms]. The half-life of 230(6) ms deduced for 53Ca is significantly longer than reported previously, where the decay chain 53K -> 53Ca -> 53Sc was considered. A delayed gamma ray with energy 247 keV as identified following beta decay of 54Ca, and is proposed to depopulate the first 1+ level in 54Sc. The beta-decay properties compare favorably with the results of shell model calculations completed in the full pf-space with the GXPF1 interaction. The half-lives of the neutron-rich Ca isotopes are also compared with gross beta-decay theory. The systematic trend of the neutron-rich Ca half-lives is consistent with the presence of a subshell gap at N=32.
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.
Evidence for the decay X(3872) -> J/\\psi\\omega
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, D.N.; 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. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /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 /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. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist 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
2011-08-11T23:59:59.000Z
We present a study of the decays B{sup 0,+} --> J/{psi}{pi}{sup +}{pi}{sup -}{pi}{sup 0}K{sup 0,+}, using 467x10{sup 6} B{anti B} pairs recorded with the BABAR detector. We present evidence for the decay mode X(3872) --> J/{psi}{omega}, with product branching fractions B(B{sup +} --> X(3872)K{sup +}) x B(X(3872) --> J/{psi}{omega}) = [0.6 {+-} 0.2(stat) {+-} 0.1(syst)] x 10{sup -5}, and B(B{sup 0} --> X(3872)K{sup 0}) x B(X(3872) --> J/{psi}{omega}) = [0.6 {+-} 0.3(stat) {+-} 0.1(syst)] x 10{sup -5}. A detailed study of the {pi}{sup +}{pi}{sup -}{pi}{sup 0} mass distribution from X(3872) decay favors a negative-parity assignment.
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 -}.
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.
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.
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.
Decay experiments to test beta - and gamma -strength functions
Hardy, J C
1981-01-01T23:59:59.000Z
The decays of six delayed-proton precursors have been studied with the particle-X-ray coincidence technique, yielding a more or less detailed view of level widths in the proton emitting nuclei. The results lead to a reevaluation of the techniques for calculating level densities and average gamma-decay widths in exotic nuclei. With these aspects of beta -delayed proton decay specified, the proton energy spectra of a number of precursors (65
The decay of a new nuclide /sup 71/Br
Hagberg, E; Evans, H C; Hardy, J C; Koslowsky, V T; Schmeing, H; Schrewe, U J; Sharma, K S
1981-01-01T23:59:59.000Z
The decay of mass-separated samples of the previously unknown nuclide /sup 71/Br have been investigated by means of the Chalk River on-line isotope separator. Eleven gamma -transitions were assigned to the decay of this nuclide and its half-life was measured to be 21.4+or-0.6 s. A simple decay scheme for /sup 71/Br has been constructed incorporating six levels in its daughter, /sup 71/Se. The half-life of the first excited state in /sup 71/Se was measured to be 5.5+or-1.0 mu s and the transition from this state to the ground state was found to be highly converted. Systematic trends in the level schemes of /sup 67 /Zn, /sup 69/Ge and /sup 71/Se are investigated. (16 refs).
- and -delayed neutron- decay of neutron-rich copper isotopes
Korgul, A. [University of Warsaw; Rykaczewski, Krzysztof Piotr [ORNL; Winger, J. A. [Oak Ridge Associated Universities (ORAU); Ilyushkin, S. [Mississippi State University (MSU); Gross, Carl J [ORNL; Batchelder, J. C. [Oak Ridge Associated Universities (ORAU); Bingham, C. R. [University of Tennessee, Knoxville (UTK); Borzov, Ivan N [ORNL; Goodin, C. [Vanderbilt University; Grzywacz, Robert Kazimierz [ORNL; Hamilton, Joseph H [ORNL; Krolas, W. [Joint Institute for Heavy Ion Research, Oak Ridge; Liddick, S. N. [Oak Ridge Associated Universities (ORAU); Mazzocchi, C. [University of Warsaw; Nelson, C. [Vanderbilt University; Nowacki, F. [Institut Pluridisciplinaire Hubert Curien, Strasbourg, France; Padgett, Stephen [University of Tennessee, Knoxville (UTK); Piechaczek, A. [Louisiana State University; Rajabali, M. M. [University of Tennessee, Knoxville (UTK); Shapira, Dan [ORNL; Sieja, K. [Technische Universitat Darmstadt, Germany; Zganjar, E. F. [Louisiana State University
2012-01-01T23:59:59.000Z
The {beta}-decay properties of neutron-rich Cu isotopes produced in proton-induced fission of {sup 238}U were studied at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The data were collected using high-resolution online mass separation, reacceleration, and digital {beta}-{gamma} spectroscopy methods. An improved decay scheme of N = 49 {sup 78}Cu and the first observation of N = 50 {sup 79}Cu {beta}-delayed neutron decay followed by a gamma transition are reported. Spin and parity (5{sup -}) are deduced for {sup 78gs}Cu. The {beta}-delayed neutron branching ratios (P{sub {beta}n}) for the {sup 77}Cu and {sup 79}Cu precursors are analyzed with the help of nuclear structure models.
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.
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.
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.
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.)
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.
FIP Bias Evolution in a Decaying Active Region
Baker, D; Démoulin, P; Yardley, S L; van Driel-Gesztelyi, L; Long, D M; Green, L M
2015-01-01T23:59:59.000Z
Solar coronal plasma composition is typically characterized by first ionization potential (FIP) bias. Using spectra obtained by Hinode's EUV Imaging Spectrometer (EIS) instrument, we present a series of large-scale, spatially resolved composition maps of active region (AR) 11389. The composition maps show how FIP bias evolves within the decaying AR from 2012 January 4-6. Globally, FIP bias decreases throughout the AR. We analyzed areas of significant plasma composition changes within the decaying AR and found that small-scale evolution in the photospheric magnetic field is closely linked to the FIP bias evolution observed in the corona. During the AR's decay phase, small bipoles emerging within supergranular cells reconnect with the pre-existing AR field, creating a pathway along which photospheric and coronal plasmas can mix. The mixing time scales are shorter than those of plasma enrichment processes. Eruptive activity also results in shifting the FIP bias closer to photospheric in the affected areas. Final...
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.
Extraction of kinetic freeze-out properties and effect of resonance decays
Levente Molnar
2005-07-21T23:59:59.000Z
We present STAR results from identified particle spectra measured in $\\sqrt{s_{NN}}$ = 62.4 GeV Au-Au collisions. Particle production and system dynamics are compared to results at $\\sqrt{s_{NN}}$ = 200 GeV. We extract kinetic and chemical freeze-out parameters using blast wave model parameterization and statistical model. We discuss the effect of resonance decays on the extracted kinetic freeze-out parameters.
Mixed Heavy Quark Hybrid Mesons, Decay Puzzles, and RHIC
Leonard S. Kisslinger
2009-06-18T23:59:59.000Z
We estimate the energy of the lowest Charmonium and Upsilon states with hybrid admixtures using the method of QCD Sum Rules. Our results show that the $\\Psi'(2S)$ and $\\Upsilon(3S)$ states both have about a 50% admixture of hybrid and meson components. From this we find explanations of both the famous $\\rho-\\pi$ puzzle for Charmonium, and the unusual pattern of $\\sigma$ decays that have been found in $\\Upsilon$ decays. Moreover, this picture can be used for predictions of heavy quark production with the octet model for RHIC.
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.
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.
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.
A Search for the Decay B+ --> K+ nu nubar
Aubert, B
2004-08-17T23:59:59.000Z
In this work the authors report the results of a search for the exclusive decay mode B{sup +} --> K{sup +}{nu}{bar {nu}}. By modifying the particle identification (PID) criteria used in the search, they additionally obtain a limit on the related decay B{sup +} --> {pi}{sup +}{nu}{bar {nu}}. The data used in this analysis were collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring.
Nuclear moments for the neutrinoless double beta decay
C. Barbero; F. Krmpotic; D. Tadic
1998-02-23T23:59:59.000Z
A derivation of the neutrinoless double beta decay rate, specially adapted for the nuclear structure calculations, is presented. It is shown that the Fourier-Bessel expansion of the hadronic currents, jointly with the angular momentum recoupling, leads to very simple final expressions for the nuclear form factors. This greatly facilitates the theoretical estimate of the half life. Our approach does not require the closure approximation, which however can be implemented if desired. The method is exemplified for the $\\beta\\beta$ decay $^{48}Ca \\to ^{48}Ti$, both within the QRPA and a shell-model like model.
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, $\\lambda$.
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.
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.
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.
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.
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
, Texas A& M University, 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...
Non-leptonic decays of charmed mesons into two Pseudoscalars
Biswas, Aritra; Abbas, Gauhar
2015-01-01T23:59:59.000Z
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 $D^0\\rightarrow K^0\\bar{K^0}$ mode. Using our unitarized amplitudes we evaluate the strong ...
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.
Neumark, Daniel M.
Decay dynamics of nascent acetonitrile and nitromethane dipole-bound anions produced (2014) Decay dynamics of nascent acetonitrile and nitromethane dipole-bound anions produced 2014; published online 13 May 2014) Decay dynamics of nascent dipole bound states of acetonitrile
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.
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.
Decay Rates for Spherical Scalar Waves in the Schwarzschild Geometry
Johann Kronthaler
2007-09-24T23:59:59.000Z
The Cauchy problem is considered for the scalar wave equation in the Schwarzschild geometry. Using an integral spectral representation we derive the exact decay rate for solutions of the Cauchy problem with spherical symmetric initial data, which is smooth and compactly supported outside the event horizon.
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.
Generator Coordinate Method framework for Double Beta Decay
Andrzej Bobyk; Wies?aw A. Kami?ski
2014-11-10T23:59:59.000Z
We propose a consistent prescription for the derivation of the particle number and angular momentum projected QRPA (PQRPA) equation in the Generator Coordinate Method (GCM) framework for calculation of NME's of double-beta decay of axially deformed nuclei. We derive closed formulae for the calculation of excitation energies and wave functions of the intermediate nucleus.
Measurement of tau-decays involving eta-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.
1992-12-01T23:59:59.000Z
The decay tau- --> nu(tau)pi-pi0eta has been observed for the first time using the CLEO-II detector at the Cornell Electron Storage Ring. The measured branching ratio (0.17 +/- 0.02 +/- 0.02)%, agrees with the CVC (conserved ...
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...
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.
Generational Garbage Collection and the Radioactive Decay Model
Clinger, William D.
Generational Garbage Collection and the Radioactive Decay Model William D Clinger and Lars T Hansen a rational basis for deciding how many objects to promote, when to collect garbage, and which generations to collect. Analysis of the model leads to a new kind of gen- erational garbage collector whose effectiveness
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 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.
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.
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.
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.
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.
Leptonic and Semileptonic Decays of D and Ds Mesons
Â· backgrounds from Ds semileptonic decays Â· Consistent results 7 PRL 100, 161801 (2008) #12;M. R. Shepherd PANIC08, Eilat November 11, 2008 Ds(,) and fDs Summary 8 (Preliminary) (Preliminary) (PRL 100, 161801 11, 2008 9 Belle (63% of current data) PRL 100, 241801 (2008) BaBar (47% of data) PRL 98, 141801
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)
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
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.
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...
First observation of the decay B-0 -> D*D+*(-)
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Davis, Robin E. P.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Zhou, L.
1999-04-01T23:59:59.000Z
We have observed four fully reconstructed B-0 --> D*+D*- candidates in 5.8 x 10(6) Y(4S) --> B (B) over bar decays recorded with the CLEO detector. The background is estimated to be 0.31 +/- 0.10 events. The probability that the background could...
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.
Two-photon decay of light scalars: a comparison of tetraquark and quarkonium assignments
Francesco Giacosa
2009-03-31T23:59:59.000Z
Two-photon decays of light scalar mesons are discussed within the quarkonium and tetraquark asignements: in both cases the decay rate of the sigma resonances turns out to be smaller than 1 keV.
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
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
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}.
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 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 . . .
Effect of first forbidden decays on the shape of neutrino spectra
Fang, Dong-Liang
2015-01-01T23:59:59.000Z
We examine the effect of First Forbidden (FF) decays on $\\beta$-decay neutrino spectra by performing microscopic nuclear structure calculations. By analyzing the FF decay branches of even-even nuclei we conclude that FF decays may be responsible for part of the missing neutrinos in the so called "Reactor Neutrino Anomaly". Further calculations and more experimental data are needed for a firm conclusion.
Effect of first forbidden decays on the shape of neutrino spectra
Dong-Liang Fang; B. Alex Brown
2015-02-08T23:59:59.000Z
We examine the effect of First Forbidden (FF) decays on $\\beta$-decay neutrino spectra by performing microscopic nuclear structure calculations. By analyzing the FF decay branches of even-even nuclei we conclude that FF decays may be responsible for part of the missing neutrinos in the so called "Reactor Neutrino Anomaly". Further calculations and more experimental data are needed for a firm conclusion.
Neutrinoless double-$?$ decay of ${}^{82}$Se in the shell model: beyond closure approximation
R. A. Sen'kov; M. Horoi; B. A. Brown
2014-05-02T23:59:59.000Z
We recently proposed a new method to calculate the standard nuclear matrix elements for neutrinoless double-$\\beta$ decay ($0\
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.
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
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.
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
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\
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
HEP/123-qed Fine structure of alpha decay in odd nuclei
M. Mirea
2000-01-01T23:59:59.000Z
Using an ? decay level scheme, the fine structure in odd nuclei is explained by taking into account the radial and rotational couplings between the unpaired valence nucleon and the core of the decaying system. It is shown that the experimental behavior of the ? decay fine structure phenomenon is governed by the dynamical characteristics of the system.
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
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 ...
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 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}|.
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.
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%.
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.
Decay of Graviton Condensates and their Generalizations in Arbitrary Dimensions
Florian Kuhnel; Bo Sundborg
2014-09-30T23:59:59.000Z
Classicalons are self-bound classical field configurations, which include black holes in General Relativity. In quantum theory, they are described by condensates of many soft quanta. In this work, their decay properties are studied in arbitrary dimensions. It is found that generically the decays of other classicalons are enhanced compared to pure graviton condensates, ie. black holes. The evaporation of higher dimensional graviton condensates turns out to match Hawking radiation solely due to non-linearites captured by the classicalon picture. Although less stable than black holes, all self-bound condensates are shown to be stable in the limit of large mass. Like for black holes, the effective coupling always scales as the inverse of the number of constituents, indicating that these systems are at critical points of quantum phase transitions. Consequences for cosmology, astro- and collider physics are briefly discussed.