On Prospects for Exploration of Supersymmetry in Double Beta Decay Experiments

We analyze constraints on the parameters of the R-parity violating supersymmetry which can be extracted from non-observation of the neutrinoless nuclear double beta decay ($0\nu\beta\beta$) at a given half-life lower bound. Our analysis covers a large class of phenomenologically viable R-parity violating SUSY models. We introduce special characteristics: the SUSY sensitivity of a $\beta\beta$ decaying isotope and the SUSY reach of a $0\nu\beta\beta$ experiment. The former provides a physical criterion for a selection of the most promising isotopes for SUSY searches and the latter gives a measure of success for a $0\nu\beta\beta$ experiment in exploring the R-parity violating SUSY parameter space. On this basis we discuss prospects for exploration of supersymmetry in various $0\nu\beta\beta$ experiments.Comment: 11 pages, 5 Postscript figures. Modified and updated version is printed also in Proc. of NANP97 (JINR, Dubna, July 7--11, 1997): Phys. Atom Nucl, 1998, 61, vol. 6, p.1092--109

College of Arts and Sciences at Governors State University Announces Winter 2008 Dean’s List

The College of Arts and Sciences at Governors State University recently recognized undergraduate students who earned a 3.7 grade point average or higher during the Winter 2008 trimester

Shell-Model Effective Operators for Muon Capture in ^{20}Ne

It has been proposed that the discrepancy between the partially-conserved axial-current prediction and the nuclear shell-model calculations of the ratio $C_P/C_A$ in the muon-capture reactions can be solved in the case of ^{28}Si by introducing effective transition operators. Recently there has been experimental interest in measuring the needed angular correlations also in ^{20}Ne. Inspired by this, we have performed a shell-model analysis employing effective transition operators in the shell-model formalism for the transition $^{20}Ne(0^+_{g.s.})+\mu^- \to ^{20}F(1^+; 1.057 MeV) + \nu_\mu$. Comparison of the calculated capture rates with existing data supports the use of effective transition operators. Based on our calculations, as soon as the experimental anisotropy data becomes available, the limits for the ratio $C_P/ C_A$ can be extracted.Comment: 9 pages, 3 figures include

Towards the solution of the CP/CAC_{P}/C_{A} anomaly in shell-model calculations of muon capture

Recently many authors have performed shell-model calculations of nuclear matrix elements determining the rates of the ordinary muon capture in light nuclei. These calculations have employed well-tested effective interactions in large scale shell-model studies. For one of the nuclei of interest, namely $^{28}$Si, there exists recent experimental data which can be used to deduce the value of the ratio $C_{P}/C_{A}$ by using the calculated matrix elements. Surprisingly enough, all the abovementioned shell-model results suggest a very small value ($\simeq 0$) for $C_{P}/C_{A}$, quite far from the PCAC prediction and recent data on muon capture in hydrogen. We show that this rather disturbing anomaly is solved by employing effective transition operators. This finding is also very important in studies of the scalar coupling of the weak charged current of leptons and hadrons.Comment: Revtex, 6 pages, 2 figs include

GEMMA experiment: three years of the search for the neutrino magnetic moment

The result of the 3-year neutrino magnetic moment measurement at the Kalinin Nuclear Power Plant with the GEMMA spectrometer is presented. Antineutrino-electron scattering is investigated. A high-purity germanium detector of 1.5 kg placed at a distance of 13.9 m from the 3 GW(th) reactor core is used in the spectrometer. The antineutrino flux is 2.7E13 1/scm/s. The differential method is used to extract (nu-e) electromagnetic scattering events. The scattered electron spectra taken in 5184+6798 and 1853+1021 hours for the reactor ON and OFF periods are compared. The upper limit for the neutrino magnetic moment < 3.2E-11 Bohr magneton at 90% CL is derived from the data processing.Comment: 4 pages, 4 figure

Search for double beta decay of 106Cd with an enriched 106CdWO4 crystal scintillator in coincidence with CdWO4 scintillation counters

Studies on double beta decay processes in 106Cd were performed by using a cadmium tungstate scintillator enriched in 106Cd at 66% (106CdWO4) with two CdWO4 scintillation counters (with natural Cd composition). No effect was observed in the data that accumulated over 26033 h. New improved half-life limits were set on the different channels and modes of the 106Cd double beta decay at level of lim T_1/2 ∼ 10^20 − 10^22 yr. The limit for the two neutrino electron capture 2νECβ with positron emission in 106Cd to the ground state of 106Pd, T_1/2 ≥ 2.1 × 10^21 yr, was set by the analysis of the 106CdWO4 data in coincidence with the energy release 511 keV in both CdWO 4 counters. The sensitivity approaches the theoretical predictions for the decay half-life that are in the range T_1/2 ∼ 10^21 − 10^22 yr. The resonant neutrinoless double-electron capture to the 2718 keV excited state of 106Pd is restricted at the level of T_1/2 (0ν2K) ≥ 2.9 × 10^21 yr