A Definitive Signal of Multiple Supersymmetry Breaking

TL;DR

This paper proposes a method to detect multiple supersymmetry breaking sectors at the LHC through LOSP decay channels, which could confirm supergravity and provide insights into early universe cosmology.

Contribution

It introduces a new decay channel involving goldstinos that evades BBN constraints, enabling potential measurement of the goldstino/gravitino mass ratio at colliders.

Findings

Possible measurement of LOSP decays into goldstino and gravitino at the LHC.

Goldstino/gravitino mass ratio of 2 would confirm multiple SUSY breaking.

Framework allows for high reheating temperatures compatible with leptogenesis.

Abstract

If the lightest observable-sector supersymmetric particle (LOSP) is charged and long-lived, then it may be possible to indirectly measure the Planck mass at the LHC and provide a spectacular confirmation of supergravity as a symmetry of nature. Unfortunately, this proposal is only feasible if the gravitino is heavy enough to be measured at colliders, and this condition is in direct conflict with constraints from big bang nucleosynthesis (BBN). In this work, we show that the BBN bound can be naturally evaded in the presence of multiple sectors which independently break supersymmetry, since there is a new decay channel of the LOSP to a goldstino. Certain regions of parameter space allow for a direct measurement of LOSP decays into both the goldstino and the gravitino at the LHC. If the goldstino/gravitino mass ratio is measured to be 2, as suggested by theory, then this would provide dramatic verification of the existence of multiple supersymmetry breaking and sequestering. A variety of consistent cosmological scenarios are obtained within this framework. In particular, if an R symmetry is imposed, then the gauge-gaugino-goldstino interaction vertices can be forbidden. In this case, there is no bound on the reheating temperature from goldstino overproduction, and thermal leptogenesis can be accommodated consistently with gravitino dark matter.