A Light Stop with a Heavy Gluino: Enlarging the Stop Gap

TL;DR

This paper presents a model where a heavy gluino does not imply a heavy stop, challenging previous assumptions by using strong dynamics to keep the stop light despite a large gluino mass.

Contribution

It introduces the Minimal Composite Supersymmetric Standard Model, showing how strong dynamics can maintain a light stop even with a heavy gluino, enlarging the stop gap.

Findings

Gluino can be about three times heavier than the stop.

Stop mass is reduced due to large anomalous dimension from strong dynamics.

Heavy gluino does not necessarily mean a heavy stop in this model.

Abstract

It is widely thought that increasing bounds on the gluino mass, which feeds down to the stop mass through renormalization group running, are making a light stop increasingly unlikely. Here we present a counter-example. We examine the case of the Minimal Composite Supersymmetric Standard Model which has a light composite stop. The large anomalous dimension of the stop from strong dynamics pushes the stop mass toward a quasi-fixed point in the infrared, which is smaller than standard estimates by a factor of a large logarithm. The gluino can be about three times heavier than the stop, which is comparable to hierarchy achieved with supersoft Dirac gluino masses. Thus, in this class of models, a heavy gluino is not necessarily indicative of a heavy stop.