arXiv:1005.1255v2 [hep-ph] 20 Aug 2010
LHC Reach of Low Scale Gauge Mediation with Perturbatively
Ryosuke Sato and Satoshi Shirai
Department of Physics, University of Tokyo,
Tokyo 113-0033, Japan
Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo,
Chiba 277-8568, Japan
Very light gravitino scenario m3/2<
cosmological problem. However in such a scenario, stability of the vacuum is an
important issue. Recently, Yonekura and one of the authors RS have investigated
the parameter space of a low scale gauge mediation with a perturbatively stable
vacuum and found that there are severe upper bounds on the gaugino masses. In
this Letter, we show that such a model can be completely excluded/discovered at
very early stage of the LHC run.
∼16 eV is very interesting, since there is no
Low scale gauge mediation is attractive, because it can achieve a very light gravitino mass
∼16 eV, which satisfies all constraints from cosmology . However in this scenario,
stability of the vacuum is an important issue . It is known that there are two kinds
of model which can have the light gravitino and a sufficiently stable vacuum. One is the
model of Refs.  using the Izawa-Yanagida-Intriligator-Thomas (IYIT) model  as a
SUSY breaking sector, and the other is the model of Refs.  gauging a flavor symmetry
of the Intriligator-Seiberg-Shih (ISS) model . The SUSY breaking vacuum of the IYIT
model is absolutely stable. Although the vacuum of the ISS model is only perturbatively
stable, the lifetime of the vacuum is independent of the gravitino mass. Therefore, these
models can have both the light gravitino and the sufficiently stable vacuum at the same
However, in these two models, it was observed that the Minimal Supersymmetric
Standard Model (MSSM) gaugino masses are suppressed. Therefore, these models are
severely constrained by the Tevatron bound [7, 8]. Recently, Yonekura and one of the
present authors RS have studied the parameter space of the low scale gauge mediation
model which has a stable SUSY breaking vacuum . As the result, they have found
almost all the parameter space is excluded by the Tevatron bound when the gravitino
mass is less than 16 eV. However, these models have not been completely excluded. To
exclude them completely, we discuss the discovery region at early stage of the LHC run.
As the result, we show that such a model can be completely excluded/discovered at very
early stage of the LHC run even if we relax the upper bound of the gravitino mass to
This Letter is organized as follows. In section 2, we review the model discussed in
Ref. . In section 3, we estimate the discovery region of the low scale gauge mediation
at the LHC.
In this section, we review two kinds of the low scale gauge mediation model.
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