Search for Pauli Exclusion Principle Violating Atomic Transitions and Electron Decay with a P-type Point Contact Germanium Detector

A search for Pauli-exclusion-principle-violating K-alpha electron transitions was performed using 89.5 kg-d of data collected with a p-type point contact high-purity germanium detector operated at the Kimballton Underground Research Facility. A lower limit on the transition lifetime of 5.8x10^30 seconds at 90% C.L. was set by looking for a peak at 10.6 keV resulting from the x-ray and Auger electrons present following the transition. A similar analysis was done to look for the decay of atomic K-shell electrons into neutrinos, resulting in a lower limit of 6.8x10^30 seconds at 90 C.L. It is estimated that the MAJORANA DEMONSTRATOR, a 44 kg array of p-type point contact detectors that will search for the neutrinoless double-beta decay of 76-Ge, could improve upon these exclusion limits by an order of magnitude after three years of operation

SU(3) Breaking Effects in Hyperon Semi-Leptonic Decays and the extraction of F and D

The analysis of hyperon semi-leptonic decay data is re-examined in the light of a recent suggestion that SU(3) symmetry breaking effects may be taken into account by applying a correction to the $F/D$ ratio obtained via naive linear extrapolation in the hyperon masses. Comparison is made with the physically better motivated approach of applying so-called centre-of-mass corrections. This study (including all available data) reveals certain short-comings of the former of the above treatments, highlights some interesting aspects of this type of analysis and attempts to pinpoint the decay data that might usefully be improved. A tantalising result of the SU(3) breaking analysis performed here is that the magnitude of recoil correction required by the data corresponds closely to that required for the standard explanation of the reduction of \gA from its SU(6) value of 5/3. We also comment on other recent suggestions for taking into account the effects of SU(3) breaking. Finally a few remarks are made on the relevance for predicting the flavour non-singlet contribution to the proton $g_1$ and the Ellis-Jaffe sum rule.Comment: 12 pages, latex, no figures. Removed extended ascii set characters in the source file that were being corrupted by some mailer

Observation of B+ -> p pbar pi+, B0 -> p pbar K0, and B+ -> p pbar K*+

We report the first observation of a b -> u type charmless baryonic B decay, B+ -> p pbar pi+, as well as b -> s type B0 -> p pbar K0 and B+ -> p pbar K*+ decays. The analysis is based on a 78fb^{-1} data sample recorded on the Upsilon(4S) resonance with the Belle detector at KEKB. We find BF(B+ -> p pbar pi+) = (3.06^{+0.73}_{-0.62} \pm 0.37)*10^{-6}, BF(B0 -> p pbar K0) =(1.88^{+0.77}_{-0.60} \pm 0.23)*10^{-6}, and BF(B+ -> p pbar K*+) = (10.3^{+3.6 + 1.3}_{-2.8 -1.7})*10^{-6}. We also update BF(B+ -> p pbar K+) = (5.66^{+0.67}_{-0.57} \pm 0.62)* 10^{-6}, and present an upper limit on BF(B0 -> p pbar K*0) at the 90% confidence level. A common feature of the observed decay modes is threshold peaking in baryon pair invariant mass.Comment: 10 pages, 12 figure file

Neutrino masses from beta decays after KamLAND and WMAP (Updated including the NC enhanced SNO data)

The first data released by the KamLAND collaboration have confirmed the strong evidence in favour of the LMA solution of the solar neutrino problem. Taking into account the ranges for the oscillation parameters allowed by the global analysis of the solar, CHOOZ and KamLAND data, we update the limits on the neutrinoless double beta decay effective neutrino mass parameter and analyze the impact of all the available data from neutrinoless double beta decay experiments on the neutrino mass bounds, in view of the latest WMAP results. For the normal neutrino mass spectrum the range (0.05-0.23) eV is obtained for the lightest neutrino mass if one takes into account the Heidelberg-Moscow evidence for neutrinoless double beta decay and the cosmological bound. It is also shown that under the same conditions the mass of the lightest neutrino may not be bounded from below if the spectrum is of the inverted type. Finnaly, we discuss how future experiments can improve the present bounds on the lightest neutrino mass set by the Troitsk, Mainz and WMAP results. In the addendum we update the allowed ranges for the effective Majorana neutrino mass parameter in view of the latest NC enhanced SNO data.Comment: Updated including the recent NC enhanced SNO data. Refferences added and typos correcte