Kazuki Sakurai

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The ATLAS and CMS experiments at the Large Hadron Collider (LHC) may discover the squarks (˜ q) and gluino (˜ g) of the minimal supersymmetric standard model (MSSM) in the early stage of the experiments if their masses are lighter than 1.5 TeV. In this paper we propose the subsystem m T 2 variable (m sub T 2), which is sensitive to the gluino mass when m ˜(More)
Fastlim is a tool to calculate conservative limits on extensions of the Standard Model from direct LHC searches without performing any Monte Carlo event generation. The program reconstructs the visible cross sections (cross sections after event selection cuts) from pre-calculated efficiency tables and cross section tables for simplified event topologies. As(More)
We present a frequentist analysis of the parameter space of the pMSSM10, in which the following ten soft SUSY-breaking parameters are specified independently at the mean scalar top mass scale M SUSY ≡ √ m ˜ t 1 m ˜ t 2 : the gaugino masses M 1,2,3 , the first-and second-generation squark masses m ˜ q 1 = m ˜ q 2 , the third-generation squark mass m ˜ q 3 ,(More)
We study the neutralino relic density in the minimal supersym-metric standard model with natural light Higgs sector in which all Higgs masses, the supersymmetry (SUSY) breaking parameters, and the higgsino mass parameter µ are of order the weak scale. To realize this situation we adopt nonuniversal Higgs masses at the grand unified scale. We show that in(More)
We study the LHC signature of the minimal supersymmetric standard model with non-universal sfermion masses. In the model, soft masses of gauginos and the 3rd generation of 10 of SU(5) are around the weak scale, while other sfermion soft mass is universal and around a few TeV. Such sfermion mass spectrum is motivated not only from flavor, CP and naturalness(More)
We propose a new possible explanation of the ATLAS di-boson excess: that it is due to heavy resonant slepton production, followed by decay into di-smuons. The smuon has a mass not too far from the W and Z masses, and so it is easily confused with W or Z bosons after its subsequent decay into di-jets, through a supersymmetry violating and R−parity violating(More)
We analyze lepton flavor violating τ → µγ and µ → eγ processes in SUSY GUT model in which sfermions have special mass spectrum. It is assumed that only third generation sfermions which are contained in 10(Q, U c , E c) of SU(5) can have a different mass from the others. This mass spectrum is led from E 6 GUT model with horizontal symmetries. It is shown(More)
Different mechanisms operate in various regions of the MSSM parameter space to bring the relic density of the lightest neutralino, ˜ χ 0 1 , assumed here to be the lightest SUSY particle (LSP) and thus the dark matter (DM) particle , into the range allowed by astrophysics and cosmol-ogy. These mechanisms include coannihilation with some nearly degenerate(More)
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