Final results of the Aurora experiment to study $2\beta$ decay of $^{116}\mathrm{Cd}$ with enriched $^{116}\mathrm{Cd}{\mathrm{WO}}_{4}$ crystal scintillators

A.S. Barabash , P. Belli , R. Bernabei , F. Cappella , V. Caracciolo , R. Cerulli , D.M. Chernyak , F.A. Danevich , S. d'Angelo , A. Incicchitti , D.V. Kasperovych , V.V. Kobychev , S.I. Konovalov , M. Laubenstein , D.V. Poda (1) , O.G. Polischuk , V.N. Shlegel , V.I. Tretyak , V.I. Umatov , Ya.V. Vasiliev

1 CSNSM - Centre de Sciences Nucléaires et de Sciences de la Matière

The double-beta decay of Cd116 has been investigated with the help of radiopure enriched Cd116WO4 crystal scintillators (mass of 1.162 kg) at the Gran Sasso underground laboratory. The half-life of Cd116 relative to the 2ν2β decay to the ground state of Sn116 was measured with the highest up-to-date accuracy as T1/2=(2.63-0.12+0.11)×1019  yr. A new improved limit on the 0ν2β decay of Cd116 to the ground state of Sn116 was set as T1/2≥2.2×1023  yr at 90% C.L., which is the most stringent known restriction for this isotope. It corresponds to the effective Majorana neutrino mass limit in the range ⟨mν⟩≤(1.0–1.7)  eV, depending on the nuclear matrix elements used in the estimations. New improved half-life limits for the 0ν2β decay with majoron(s) emission, Lorentz-violating 2ν2β decay, and 2β transitions to excited states of Sn116 were set at the level of T1/2≥1020–1022  yr. New limits for the hypothetical lepton-number violating parameters (right-handed currents admixtures in weak interaction, the effective majoron-neutrino coupling constants, R-parity violating parameter, Lorentz-violating parameter, heavy neutrino mass) were set.

Mots clés: 29.40.Mc; 11.30.Fs; 23.40.-s; Particle Physics Experiments; scintillation counter: crystal; neutrino: Majorana: mass; neutrino: mass; lepton number: violation; R parity: violation; neutrino: heavy; semileptonic decay; energy: ground state; double-beta decay: (0neutrino); weak interaction: coupling constant; excited state: energy; Gran Sasso; energy spectrum; numerical calculations; cadmium: nuclide; detector: energy resolution; double-beta decay: (2neutrino); coupling constant: axial; S076ETA; S076H0N; S076H2N; S076MW

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

A.S. Barabash, P. Belli, R. Bernabei, F. Cappella, V. Caracciolo, et al.. Final results of the Aurora experiment to study $2\beta$ decay of $^{116}\mathrm{Cd}$ with enriched $^{116}\mathrm{Cd}{\mathrm{WO}}_{4}$ crystal scintillators. Phys.Rev.D, 2018, 98 (9), pp.092007. ⟨10.1103/PhysRevD.98.092007⟩. ⟨hal-01937823⟩