Speaker
Description
The ACCESS (Array of Cryogenic Calorimeters to Evaluate Spectral Shapes) project aims to establish a novel detector to perform a precise study of the spectral shape of forbidden β-decays. These strongly suppressed processes can help to clarify the long-standing issue of the axial coupling constant (gA) quenching. Moreover, such rare decays are also a common source of systematic uncertainty in Dark Matter and Neutrinoless Double Beta Decay experiments, where detailed knowledge of the shape of the background spectrum is required. In this talk, we will present a brief review of the ACCESS research program, aiming to study natural (Cd-113 and In-115) and synthetic isotopes (Tc-99), which will be measured with a common experimental technique. The main attention will be dedicated to the current status of the research program and recent promising results achieved for In-115. Using an InI crystal equipped with a small Ge-NTD thermistor an energy resolution of 3.1 keV FWHM at 60 keV and a low-energy threshold of 17 keV were achieved. The physics data acquired over a 300-h-long cryogenic run were analyzed and presented.
