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Ryosuke Sato

Publications and source records attributed to Ryosuke Sato.

95 records · Page 6Linked to original sources

A Possible Interpretation of CDF Dijet Mass Anomaly and its Realization in Supersymmetry

Recently, the CDF collaboration reports an anomaly in dijet mass distribution in association with a lepton and missing energy. We discuss a possibility that the origin of the lepton and missing energy comes not from a W boson but a new boson particle, which is also responsible for the dijet mass peak. We show that such a situation can be realized in the framework of the minimal supersymmetric standard model and the dijet anomaly can be explained.

hep-ph↗

Gravitino Dark Matter and Light Gluino in an R-invariant Low Scale Gauge Mediation

We consider the simplest class of the R-invariant gauge mediation model with the gravitino mass in the one to ten keV range. We show that the entropy production from the supersymmetry breaking sector makes the gravitino into a warm dark matter candidate. We also discuss that the gluino mass can be lighter than the wino mass even when the messenger sector satisfies the GUT relations at the GUT scale.

hep-ph↗

LHC Reach of Low Scale Gauge Mediation with Perturbatively Stable Vacuum

Very light gravitino scenario m_{3/2} < 16 eV is very interesting, since there is no 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 bound on the gaugino masses. In this paper, we show that such a model can be completely excluded/discovered at very early stage of the LHC run.

hep-ph↗

Low Scale Direct Gauge Mediation with Perturbatively Stable Vacuum

In a class of direct gauge mediation with a perturbatively stable SUSY breaking vacuum, gaugino masses vanish at the leading order of SUSY breaking F-term. We study the allowed parameter space of the gauge mediation models. By imposing a Tevatron bound on the lightest chargino mass m_{{\tilde χ}^\pm_1} > 270 GeV and a warm dark-matter mass bound on the light gravitino mass m_{3/2} < 16 eV, we find that almost all the parameter space is excluded. Near future experiments may completely exclude, or possibly discover, the scenario.

hep-ph↗

Relaxing a constraint on the number of messengers in a low-scale gauge mediation

We propose a mechanism for relaxing a constraint on the number of messengers in low-scale gauge mediation models. The Landau pole problem for the standard-model gauge coupling constants in the low-scale gauge mediation can be circumvented by using our mechanism. An essential ingredient is a large positive anomalous dimension of messenger fields given by a large Yukawa coupling in a conformal field theory at high energies. The positive anomalous dimension reduces the contribution of the messengers to the beta function of the standard-model gauge couplings.

hep-ph↗