Updating neutrino magnetic moment constraints

Cañas, B.C. (Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740, DF, Mexico, 07000, Mexico) ; Miranda, O.G. (Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740, DF, Mexico, 07000, Mexico) ; Parada, A. (Universidad Santiago de Cali, Campus Pampalinda, Calle 5 No. 6200, Santiago de Cali, 760001, Colombia) ; Tórtola, M. (AHEP Group, Institut de Física Corpuscular – C.S.I.C., Universitat de València, Parc Cientific de Paterna, C/Catedratico José Beltrán, 2, Paterna, València, E-46980, Spain) ; Valle, J.W.F. (AHEP Group, Institut de Física Corpuscular – C.S.I.C., Universitat de València, Parc Cientific de Paterna, C/Catedratico José Beltrán, 2, Paterna, València, E-46980, Spain)

08 December 2015

Abstract: In this paper we provide an updated analysis of the neutrino magnetic moments (NMMs), discussing both the constraints on the magnitudes of the three transition moments Λi and the role of the CP violating phases present both in the mixing matrix and in the NMM matrix. The scattering of solar neutrinos off electrons in Borexino provides the most stringent restrictions, due to its robust statistics and the low energies observed, below 1 MeV. Our new limit on the effective neutrino magnetic moment which follows from the most recent Borexino data is 3.1×10−11μB at 90% C.L. This corresponds to the individual transition magnetic moment constraints: |Λ1|≤5.6×10−11μB , |Λ2|≤4.0×10−11μB , and |Λ3|≤3.1×10−11μB (90% C.L.), irrespective of any complex phase. Indeed, the incoherent admixture of neutrino mass eigenstates present in the solar flux makes Borexino insensitive to the Majorana phases present in the NMM matrix. For this reason we also provide a global analysis including the case of reactor and accelerator neutrino sources, presenting the resulting constraints for different values of the relevant CP phases. Improved reactor and accelerator neutrino experiments will be needed in order to underpin the full profile of the neutrino electromagnetic properties.


Published in: Physics letters B (2015)
Published by: Elsevier
DOI: 10.1016/j.physletb.2015.12.011
License: CC-BY-3.0



Back to search

Fulltext:
Download fulltextXML Download fulltextPDF Download fulltextPDF (PDFA)