Constraining visible neutrino decay at KamLAND and JUNO

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2020-10, Vol.80 (10), p.1-15, Article 999
• Main Authors: Porto-Silva, Yago P., Prakash, Suprabh, Peres, O. L. G., Nunokawa, Hiroshi, Minakata, Hisakazu
• Format: Article
• Language: English
• Subjects: Astronomy; Astrophysics and Cosmology; Constraint modelling; Couplings; Decay; Dependence; Elementary Particles; Hadrons; Heavy Ions; Measurement Science and Instrumentation; Neutrinos; Nuclear Energy; Nuclear Physics; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Regular Article - Theoretical Physics; String Theory
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-020-08573-9

We study visible neutrino decay at the reactor neutrino experiments KamLAND and, JUNO. Assuming the Majoron model of neutrino decay, we obtain constraints on the couplings between Majoron and neutrino as well as on the lifetime/mass of the most massive neutrino state i.e., τ 3 / m 3 or τ 2 / m 2 , respectively, for the normal or the inverted mass orderings. We obtain the constraints on the lifetime τ 2 / m 2 ≥ 1.4 × 10 - 9 s / eV in the inverted mass ordering for both KamLAND and JUNO at 90% CL. In the normal ordering in which the bound can be obtained for JUNO only, the constraint is milder than the inverted ordering case, τ 3 / m 3 ≥ 1.0 × 10 - 10  s/eV at 90% CL. We find that the dependence of lightest neutrino mass ( = m lightest ), m 1 ( m 3 ) for the normal (inverted) mass ordering, on the constraints for the different types of couplings (scalar or pseudo-scalar) is rather strong, but the m lightest dependence on the lifetime/mass bound is only modest.