Magnetic Moment of Leptons

TL;DR

This paper investigates how the magnetic moments of leptons are significantly altered in a thermal environment, with implications for early universe conditions and particle physics.

Contribution

It provides a detailed analysis of thermal corrections to lepton magnetic moments, highlighting differences between charged leptons and neutrinos in the early universe.

Findings

Thermal corrections to lepton magnetic moments depend on temperature and lepton mass.

In the early universe, lepton masses grow quadratically with temperature, affecting magnetic moments.

Thermal effects on neutrino dipole moments are proportional to neutrino mass, differing from charged leptons.

Abstract

We show that the magnetic moment of leptons is significantly modified in thermal background as compared to the corresponding vacuum value. We compare the magnetic moment of all different leptons near nucleosynthesis. It is shown that the significance of thermal corrections depends on the temperature of the universe and the respective lepton mass. In the early universe, particle mass was growing quadratically with temperature which affects the corresponding value of magnetic moment. Intrinsic magnetic moment is inversely proportional to mass whereas thermal corrections to the neutrino dipole moment is proportional to neutrino mass for the Dirac type neutrino in the minimal standard model. Therefore the effect of temperature is not the same for charged leptons and neutrinos.