Cecilia Ferrari | Searcharxiv

arXiv2026

First Experimental Limit on the Thermal Solar Neutrino Flux

The neutrino sky below 165\,keV is yet to be explored. This region provides a unique probe of stellar cooling mechanisms through the detection of thermal solar neutrinos and the low-energy tail of the $pp$ solar cycle. Here, we investigate prospects for probing this regime via neutrino capture on tritium. Analyzing KATRIN public data, we set the first experimental bound on the thermal solar neutrino flux $\Phi/\Phi_{\mathrm{SSM}} < 1.86 \times 10^{18}$ at 95\%~CL ($1.58\times10^{18}$ at 90\%~CL), and show that a $100\;\text{kg}\cdot\text{yr}$ exposure would constrain the thermal solar neutrino component to $\Phi/\Phi_{\mathrm{SSM}} \lesssim 10^4$ and detect the low-energy $pp$ flux at the Standard Solar Model (SSM) level. Neutrino--electron elastic scattering from $pp$ cycle neutrinos are identified as an irreducible background for neutrino capture searches.

hep-ph↗

arXiv2022

The matrix optimum filter for Low Temperature Detectors dead-time reduction

Experiments aiming at high sensitivities usually demand for a very high statistics in order to reach more precise measurements. However, for those exploiting Low Temperature Detectors (LTDs), a high source activity may represent a drawback, if the events rate becomes comparable with the detector characteristic temporal response. Indeed, since commonly used optimum filtering approaches can only process LTDs signals well isolated in time, a non-negligible part of the recorded experimental data-set is discarded and hence constitute the dead-time. In the presented study we demonstrate that, thanks to the matrix optimum filtering approach, the dead-time of an experiment exploiting LTDs can be strongly reduced.

physics.data-an↗