Speaker
Description
In this presentation, we will report two new studies on the spectral shape: the $2\nu\beta\beta$ decay of the $^{100}$Mo in the CUPID-Mo experiment, and the $^{113}$Cd $\beta$ decay in the framework of the CROSS project. The CUPID-Mo experiment is a demonstrator for the next generation 0νββ experiment CUPID.
The experiment is an array of 20 enriched Li$_2$$^{100}$MoO$_4$ bolometers and 20 Ge light detectors, working at 20 mK. We will present the measurement of $2\nu\beta\beta$ decay half-life of $^{100}$Mo to the ground state of $^{100}$Ru, which is the most precise measurement to date of a $2\nu\beta\beta$ decay rate in $^{100}$Mo. We will also present a measurement of higher-order corrections to the spectral shape which provides complementary nuclear structure information. We will report a novel measurement of the shape factor $\xi_{3,1}$, which is compared to theoretical predictions for different values of the effective axial-vector coupling constant.
We will present a study of a CdWO$_4$ scintillating crystal which allows to extract the $\beta$ decay spectrum of $^{113}$Cd. Within the spectrum-shape method, we performed a fit of the experimental data to extract the $g_A^{\text{eff}}$ and the small relativistic nuclear matrix element. This method allows to fit the spectral shape as well as the half-life.
