Abstract
The determination of the effective axial-vector coupling constant 𝑔A in nuclear media is a major open problem in contemporary neutrino and nuclear physics. Its deviation from the free-nucleon value directly affects the interpretation of neutrinoless double beta decay (0𝜈𝛽𝛽) searches through the associated nuclear matrix elements, and therefore impacts the extraction of constraints on the Majorana neutrino mass scale and other parameters in models that allow for lepton number violation.
The GAIAS (GAxIal Analysis with Scintillators) experiment addresses this problem through high-precision beta spectroscopy of forbidden non-unique beta decays using high optical quality and low-background crystal scintillators. These decays exhibit a strong sensitivity of the beta spectral shape to 𝑔A, especially at low energies, making them a powerful probe of nuclear models that describes weak interactions in nuclei.
The experiment is being installed at the underground Gran Sasso National Laboratory (LNGS) of INFN, where the ultra-low-background environment enables high-statistics measurements
under highly stable conditions. Particular attention will be devoted to crystal growth and isotope incorporation techniques. GAIAS aims to provide very precise beta spectrum measurement, improving constraints on the effective axial coupling constant and to strengthen the role of functional crystalline materials in frontier research at the interface of nuclear, particle, and astroparticle physics.
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Authors
Leoncini, Alice
Agnihotri, Aagrah
Atzori Corona, Mattia
Belli, Pierluigi
Bussolotti, Andrea
Cappella, Fabio
Caracciolo, Vincenzo
Cerulli, Riccardo
Danevich, Fedor
Giarnetti, Alessio
Incicchitti, Antonella
Kasperovych, Dmytro
Klavdiienko, Volodymyr
Kobychev, Vladislav
Kotila, Jenni
Mattei, Angelo
Merlo, Vittorio
Ramalho, Marlom
Suhonen, Jouni
Tretyak, Volodymyr
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Speaker
Alice Leoncini
Dipartimento di Fisica, Università di Roma "Tor Vergata”
INFN Roma 2
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