학술논문
Measurement of the $2\nu\beta\beta$ decay rate and spectral shape of $^{100}$Mo from the CUPID-Mo experiment
Document Type
Working Paper
Author
Augier, C.; Barabash, A. S.; Bellini, F.; Benato, G.; Beretta, 6 M.; Berge, L.; Billard, J.; Borovlev, Yu. A.; Cardani, L.; Casali, N.; Cazes, A.; Celi, E.; Chapellier, M.; Chiesa, D.; Dafinei, I.; Danevich, F. A.; De Jesus, M.; Dixon, T.; Dumoulin, L.; Eitel, K.; Ferri, F.; Fujikawa, B. K.; Gascon, J.; Gironi, L.; Giuliani, A.; Grigorieva, V. D.; Gros, M.; Helis, D. L.; Huang, H. Z.; Huang, R.; Imbert, L.; Johnston, J.; Juillard, A.; Khalife, H.; Kleifges, M.; Kobychev, V. V.; Kolomensky, Yu. G.; Konovalov, S. I.; Kotila, J.; Loaiza, P.; Ma, L.; Makarov, E. P.; de Marcillac, P.; Mariam, R.; Marini, L.; Marnieros, S.; Navick, X. -F.; Nones, C.; Norman, E. B.; Olivieri, E.; Ouellet, J. L.; Pagnanini, L.; Pattavina, L.; Paul, B.; Pavan, M.; Peng, H.; Pessina, G.; Pirro, S.; Poda, D. V.; Polischuk, O. G.; Pozzi, S.; Previtali, E.; Redon, Th.; Rojas, A.; Rozov, S.; Sanglard, V.; Scarpaci, J. A.; Schmidt, B.; Shen, Y.; Shlegel, V. N.; Simkovic, F.; Singh, V.; Tomei, C.; Tretyak, V. I.; Umatov, V. I.; Vagneron, L.; Velazquez, M.; Ware, B.; Welliver, B.; Winslow, L.; Xue, M.; Yakushev, E.; Zarytskyy, M.; Zolotarova, A. S.
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Abstract
Neutrinoless double beta decay ($0\nu\beta\beta$) is a yet unobserved nuclear process which would demonstrate Lepton Number violation, a clear evidence of beyond Standard Model physics. The process two neutrino double beta decay ($2\nu\beta\beta)$ is allowed by the Standard Model and has been measured in numerous experiments. In this letter, we report a measurement of $2\nu\beta\beta$ decay half-life of $^{100}$Mo to the ground state of $^{100}$Ru of $(7.07~\pm~0.02~\text{(stat.)}~\pm~0.11~\text{(syst.)})~\times~10^{18}$~yr by the CUPID-Mo experiment. With a relative precision of $\pm~1.6$ \% this is the most precise measurement to date of a $2\nu\beta\beta$ decay rate in $^{100}$Mo. In addition, we constrain higher-order corrections to the spectral shape which provides complementary nuclear structure information. We report a novel measurement of the shape factor $\xi_{3,1}=0.45~\pm 0.03~\text{(stat.)} \ \pm 0.05 \ \text{(syst.)}$, which is compared to theoretical predictions for different nuclear models. We also extract the first value for the effective axial vector coupling constant obtained from a spectral shape study of $2\nu\beta\beta$ decay.
Comment: 8 pages, 5 figures
Comment: 8 pages, 5 figures