Tue·Aug 23, 2011Tuesday·August 23, 2011

1. 01*

   Observation of Two-Neutrino Double-Beta Decay in Xe-136 with EXO-200

   N. Ackerman · B. Aharmim · M. Auger · D. J. Auty · P. S. Barbeau · K. Barry · L. Bartoszek · E. Beauchamp · V. Belov · C. Benitez-Medina · M. Breidenbach · A. Burenkov and 91 other authors

   We report the observation of two-neutrino double-beta decay in Xe-136 with T_1/2 = 2.11 +- 0.04 (stat.) +- 0.21 (sys.) x 10^21 yr. This second order process, predicted by the Standard Model, has been observed for several nuclei but not for Xe-136. The observed decay rate provides new input to matrix element calculations and to the search for the more interesting neutrino-less double-beta decay, the most sensitive probe for the existence of Majorana particles and the measurement of the neutrino mass scale.

   nucl-exhep-exphysics.ins-detPRL(2011)·262 citations
2. 02*

   Double-beta decay of ${}^{130}$Te to the first 0${}^{+}$ excited state of ${}^{130}$Xe with CUORICINO

   E. Andreotti🇮🇹 · C. Arnaboldi🇮🇹 · F. T. Avignone III🇺🇸 · M. Balata🇮🇹 · I. Bandac🇺🇸 · M. Barucci🇮🇹 · J. W. Beeman🇺🇸 · F. Bellini🇮🇹 · C. Brofferio🇮🇹 · A. Bryant🇺🇸 · C. Bucci🇮🇹 · L. Canonica🇮🇹 and 54 other authors

   The CUORICINO experiment was an array of 62 TeO${}_2$ single-crystal bolometers with a total ${}^{130}$Te mass of $11.3$kg. The experiment finished in 2008 after more than 3 years of active operating time. Searches for both $0\nu$ and $2\nu$ double-beta decay to the first excited $0^{+}$ state in ${}^{130}$Xe were performed by studying different coincidence scenarios. The analysis was based on data representing a total exposure of N(${}^{130}$Te)$\cdot$t=$9.5\times 10^{25}$y. No evidence for a signal was found. The resulting lower limits on the half lives are $T_{1/2}^{2\nu }{(}^{130}Te{\to }^{130}X{e}^{\ast })>1.3\times 10^{23}$y (90% C.L.), and $T_{1/2}^{0\nu }{(}^{130}Te{\to }^{130}X{e}^{\ast })>9.4\times 10^{23}$y (90% C.L.).

   nucl-exPRC(2012)·33 citations
3. 03*

   Nucleon to $\Delta$ and $\Delta$ form factors in Lattice QCD

   Constantia Alexandrou (Univ. of Cyprus and Cyprus Inst)🇨🇾

   We present recent lattice QCD results on the electroweak nucleon to $\Delta$ transition and $\Delta$ form factors using dynamical fermion gauge configurations with a lowest pion mass of about 300 MeV, with special emphasis in the determination of the sub-dominant quadrupole $N{\gamma }^{\ast }\to \Delta$ and $\Delta$ electromagnetic form factors.

   ↳ hep-lathep-phnucl-exnucl-thAIP Conf.Proc.(2012)·4 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.