Decoupling of Massive Right-handed Neutrinos

TL;DR

This paper explores how anomalous effects influence the decoupling of massive right-handed neutrinos, suggesting potential bounds on their mass that challenge previous assumptions about their relative scale to gauge bosons.

Contribution

It introduces a novel analysis of anomalous B+L violation effects on right-handed neutrino decoupling, proposing a possible shift from upper to lower mass bounds around 100 TeV.

Findings

Upper bound on neutrino mass ~700 GeV from standard calculations.

Anomalous effects could imply a lower bound near 100 TeV.

Decoupling behavior is significantly affected by SU(2)_R anomalies.

Abstract

We investigate the effect of B+L - violating anomalous generation of massive right-handed neutrinos on their decoupling, when the right-handed neutrino mass is considerably greater than the right-handed gauge boson masses. Considering normal annihilation channels, the Lee-Weinberg type of calculation, in this case, gives an upper bound of about 700 Gev, which casts doubt on the existence of such a right-handed neutrino mass greater than right-handed gauge boson masses. We examine the possibility that a consideration of anomalous effects related to the SU(2)_R gauge group may turn this into a lower bound of the order of 100 Tev.