Constraint on the axion-electron coupling constant and the neutrino magnetic dipole moment by using the tip-RGB luminosity of fifty globular clusters

Abstract

The current constraints in the neutrino magnetic dipole moment and axion-electron coupling constant ($\hat{\mathrm{I}}{¼}_{\hat{\mathrm{I}}}½\le 2.2\times 10^{-12}\hat{\mathrm{I}}{¼}_{\mathrm{B}}$ and $\hat{\mathrm{I}}{\pm }_{\mathrm{ae}}\le 0.5\times 10^{-26}$) are tested against the observational calibration on the tip-RGB of fifty galactic globular clusters, covering $-1.95\le [M/H]\le +0.04$. When each energy sink is introduced into stellar models separately, the current known constraints predict a tip-RGB bolometric luminosity that does not conflict the calibration, while when they are assumed to occur simultaneously, these constraints can be lowered down by 50\% and 75\%.

To be submitted to Astroparticle Physics Journal