R. L. Brodzinski

The IGEX Ge-76 neutrinoless double beta decay experiment: Prospects for next generation experiments

The International Germanium Experiment (IGEX) has analyzed 117 mole yr of 76Ge data from its isotopically enriched (86% 76Ge) germanium detectors. Applying pulse-shape discrimination (PSD) to the more recent data, the lower bound on the half-life for neutrinoless double-beta decay of 76Ge is:

Comment on "Evidence for Neutrinoless Double Beta Decay"

T_{1/2}(0\nu)> 1.57 \times 10^{25}

A decommissioned LHC model magnet as an axion telescope

yr (90% C.L.). This corresponds to an upper bound in the Majorana neutrino mass parameter,

Confirmation of the observation of 2v ββ decay of 76Ge

, between 0.33 eV and 1.35 eV, depending on the choice of theoretical nuclear matrix elements used in the analysis.

Further reduction of radioactive backgrounds in ultrasensitive germanium spectrometers

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.

New constraints on WIMPS from the Canfranc IGEX dark matter search

The 8.4 T, 10 m long transverse magnetic field of a twin aperture LHC bending magnet can be utilized as a macroscopic coherent solar axion-to-photon converter. Numerical calculations show that the integrated time of alignment with the Sun would be 33 days/yr with the magnet on a tracking table capable of

Recent results of the IGEX 76Ge double-beta decay experiment

5i in the vertical direction and

The Majorana neutrinoless double-beta decay experiment

40i in the horizontal direction. The existing lower bound on the axion-to-photon coupling constant can be improved by a factor between 30 and 100 in 3 yr, i.e., g !cc [9]10~11 GeV~1 for axion masses [ 1 eV. This value falls within the existing open axion mass window. The same set-up can simultaneously search for low- and high-energy celestial axions, or axion-like particles, scanning the sky as the Earth rotates and orbits the Sun. ( 1999 Elsevier Science B.V. All rights reserved.

Pulse shape discrimination in the IGEX experiment

Abstract A small, natural abundance, germanium detector (COSME) has been operating recently at the Canfranc Underground Laboratory (Spanish Pyrenees) in improved conditions of shielding and overburden with respect to a previous operation of the same detector (Nucl. Instrum. Meth. A 321 (1992) 410; Phys. Rev. D 51 (1995) 1458). An exposure of 72.7 kg day in these conditions has at present a background improvement of about one order of magnitude compared to the former operation of the detector. These new data have been applied to a direct search for weakly interacting massive particles (WIMPs) and solar axions. New WIMP exclusion plots improving the current bounds for low masses are reported. The paper also presents a limit on the axion–photon coupling obtained from the analysis of the data looking for a Primakoff axion-to-photon conversion and Bragg scattering inside the crystal.