Probing the reheating temperature at colliders and with primordial nucleosynthesis

Abstract

Considering gravitino dark matter scenarios with a long-lived charged slepton, we show that collider measurements of the slepton mass and its lifetime can probe not only the gravitino mass but also the post-inflationary reheating temperature TR. In a model independent way, we derive upper limits on TR and discuss them in light of the constraints from the primordial catalysis of 6Li through bound-state effects. In the collider-friendly region of slepton masses below 1 TeV, the obtained conservative estimate of the maximum reheating temperature is about TR=3×109 GeV for the limiting case of a small gluino–slepton mass splitting and about TR=108 GeV for the case that is typical for universal soft supersymmetry breaking parameters at the scale of grand unification. We find that a determination of the gluino–slepton mass ratio at the Large Hadron Collider will test the possibility of TR>109 GeV and thereby the viability of thermal leptogenesis with hierarchical heavy right-handed Majorana neutrinos.