The Effect of the Sparticle Mass Spectrum on the Conversion of B-L to B

TL;DR

This paper examines how the sparticle mass spectrum influences the conversion of B-L to B in supersymmetric models, correcting previous misconceptions and providing formulas that impact baryogenesis scenarios and reheating temperature bounds.

Contribution

It corrects a common misconception about B-L to B conversion in supersymmetry by including kinematic effects of sparticle masses and provides explicit conversion formulas.

Findings

Sparticle masses can significantly alter B-L to B conversion factors.

The correction can be a factor of 2/3 in mSUGRA scenarios.

Conversion can sometimes flip the sign of B relative to B-L.

Abstract

In the context of many leptogenesis and baryogenesis scenarios, B-L (baryon minus the lepton number) is converted into B (baryon number) by non-perturbative B+L violating operators in the SU(2)_L sector. We correct a common misconversion of B-L to B in the literature in the context of supersymmetry. More specifically, kinematic effects associated with the sparticle masses can be generically important (typically a factor of 2/3 correction in mSUGRA scenarios), and in some cases, it may even flip the sign between B-L and B. We give explicit formulae for converting B-L to B for temperatures approaching the electroweak phase transition temperature from above. Enhancements of B are also possible, leading to a mild relaxation of the reheating temperature bounds coming from gravitino constraints.