New measurement of double beta decays of ¹⁰⁰Mo to excited states of ¹⁰⁰Ru with the CUPID-Mo experiment

2022/07/19 by C. Rolfs for LUNA Collaboration, C. Augier, Mo Collaboration +160
Physics and Astronomy · #Nuclear physics research studies #Neutrino Physics Research #Advanced Chemical Physics Studies

paper · pdf · doi:10.48550/arxiv.2207.09577

Abstract

The CUPID-Mo experiment, located at Laboratoire Souterrain de Modane (France), was a demonstrator experiment for CUPID. It consisted of an array of 20 Li₂¹⁰⁰MoO₄ (LMO) calorimeters each equipped with a Ge light detector (LD) for particle identification. In this work, we present the result of a search for two-neutrino and neutrinoless double beta decays of ¹⁰⁰Mo to the first 0⁺ and 2⁺ excited states of ¹⁰⁰Ru using the full CUPID-Mo exposure (2.71 kg×yr of LMO). We measure the half-life of 2νββ decay to the 0⁺₁ state as T_1/2^{2ν→ 0₁+}=7.5± 0.8 (stat.) ^{+ 0.4}_-0.3 (syst.) )× 10²⁰ yr. The bolometric technique enables measurement of the electron energies as well as the gamma rays from nuclear de-excitation and this allows us to set new limits on the two-neutrino decay to the 2₁⁺ state of T^{2ν→ 2₁+}_1/2>4.4× 10²¹ yr (90 % c.i.) and on the neutrinoless modes of T_1/2^{0ν→ 2₁+}>2.1×10²³ yr (90 % c.i.), T_1/2^{0ν→ 0₁+}>1.2×10²³ yr (90 % c.i.). Information on the electrons spectral shape is obtained which allows us to make the first comparison of the single state (SSD) and higher state (HSD) 2νββ decay models for the 0₁⁺ excited state of ¹⁰⁰Ru.

Related

• Measurement of the 2νββ decay rate and spectral shape of ¹⁰⁰Mo from the CUPID-Mo experiment
• Searching for Beyond the Standard Model physics using the improved description of ¹⁰⁰Mo 2νββ decay spectral shape with CUPID-Mo
• Final results from the CUPID-Mo 0νββ experiment
• Search for Periodic Modulations of the Rate of Double-Beta Decay of ¹⁰⁰Mo in the NEMO-3 Detector
• Sensitivity of the CUPID experiment to 0νββ decay of ¹⁰⁰Mo