Sho Iwamoto

Higgs Mass and Muon Anomalous Magnetic Moment in Supersymmetric Models with Vector-Like Matters

We study the muon anomalous magnetic moment (muon g-2) and the Higgs boson mass in a simple extension of the minimal supersymmetric (SUSY) standard model with extra vectorlike matters, in the frameworks of gauge-mediated SUSY breaking (GMSB) models and gravity mediation (mSUGRA) models. It is shown that the deviation of the muon g-2 and a relatively heavy Higgs boson can be simultaneously explained in large tan{beta} region. (i) In GMSB models, the Higgs mass can be more than 135 GeV (130 GeV) in the region where the muon g-2 is consistent with the experimental value at the 2{sigma} (1{sigma}) level, while maintaining the perturbative coupling unification. (ii) In the case of mSUGRA models with universal soft masses, the Higgs mass can be as large as about 130 GeV when the muon g-2 is consistent with the experimental value at the 2{sigma} level. In both cases, the Higgs mass can be above 140 GeV if the g-2 constraint is not imposed.

Muon g-2 vs LHC in Supersymmetric Models

A bstractThere is more than 3σ deviation between the experimental and theoretical results of the muon g − 2. When interpreted in SUSY extensions of the SM, this anomaly suggests that some of the SUSY particles have a mass of order 100 GeV. We study searches for those particles at the LHC with particular attention to the muon g − 2. In particular, the recent results on the searches for the non-colored SUSY particles are investigated in the parameter region where the muon g − 2 is explained. The analysis is independent of details of the SUSY models. Future prospects of the collider searches are also discussed.

Higgs mass and muon anomalous magnetic moment in the U(1)- extended MSSM

We study phenomenological aspects of the MSSM with extra U(1) gauge symmetry. We find that the lightest Higgs boson mass can be increased up to 125 GeV, without introducing a large SUSY scale or large A-terms, in the frameworks of the CMSSM and gauge mediated SUSY breaking (GMSB) models. This scenario can simultaneously explain the discrepancy of the muon anomalous magnetic moment (muon g-2) at the 1 sigma level, in both of the frameworks, U(1)-extended CMSSM/GMSB models. In the CMSSM case, the dark matter abundance can also be explained.

Lepton flavor violation and cosmological constraints on R-parity violation

In supersymmetric standard models R-parity violating couplings are severely constrained, since otherwise they would erase the existing baryon asymmetry before the electroweak transition. It is often claimed that this cosmological constraint can be circumvented if the baryon number and one of the lepton flavor numbers are sufficiently conserved in these R-parity violating couplings, because B/3−Li for each lepton flavor is separately conserved by the sphaleron process. We discuss the effect of lepton flavor violation on the B−L conservation, and show that even tiny slepton mixing angles θ12(10−4) and θ23,θ13(10−5) will spoil the separate B/3−Li conservation. In particular, if lepton flavor violations are observed in experiments such as MEG and B-factories, it will imply that all the R-parity violating couplings must be suppressed to avoid the B−L erasure. We also discuss the implication for the decay of the lightest MSSM particle at the LHC.

Vacuum stability bound on extended GMSB models

A bstractExtensions of GMSB models were recently explored to explain the recent reports of the Higgs boson mass around 124 − 126 GeV. Some models predict a large μ term, which can spoil the vacuum stability of the universe. We study two GMSB extensions: i) the model with a large trilinear coupling of the top squark, and ii) that with extra vector- like matters. In both models, the vacuum stability condition provides upper bounds on the gluino mass if combined with the muon g − 2. The whole parameter region is expected to be covered by LHC at

Gauge mediation models with vectorlike matters at the LHC

\sqrt {s} = {\text{14TeV}}

CP-safe gravity mediation and muon g − 2

. The analysis is also applied to the mSUGRA models with the vector-like matters.

Recent Result of the AMS-02 Experiment and Decaying Gravitino Dark Matter in Gauge Mediation

A bstractGauge mediation model with vectorlike matters (V-GMSB) is one of the few viable SUSY models that explains the 126GeV Higgs boson mass and the muon anomalous magnetic moment simultaneously. We explore exclusion bounds on V-GMSB model from latest LHC SUSY searches.

Reconstructing supersymmetric contribution to muon anomalous magnetic dipole moment at ILC

We propose a CP-safe gravity mediation model, where the phases of the Higgs B parameter, scalar trilinear couplings and gaugino mass parameters are all aligned. Since all dangerous CP violating phases are suppressed, we are now safe to consider low-energy SUSY scenarios. As an application, we consider a gravity mediation model explaining the observed muong 2 anomaly. The CP-safe property originates i ;

Stau Kinks at the LHC

A bstractThe AMS-02 collaboration has recently reported an excess of cosmic-ray positron fractions, which is consistent with previous results at the PAMELA experiment. The result indicates the existence of new physics phenomena to provide the origin of the energetic cosmic-ray positron. We pursue the possibility that the enhancement of the positron fraction is due to decays of gravitino dark matter. We discuss that such a scenario viably fits into the models in which the soft SUSY breaking parameters emerge dominantly from gauge-mediation mechanism with superparticle masses of around 10 TeV. Our scenario is compatible with the 126 GeV Higgs boson, negative results from searches for SUSY particles, and non-observation of anomalous flavor-changing processes. We also point out that the scenario will be tested in near future by measuring the electric dipole moment of the electron and the lepton flavor violating decay of the muon.