Mar. 29, 2008 LHC 研究会 Axionic Mirage Mediation Tohoku Univ. Shuntaro Nakamura Collaborated with K. Okumura and M. Yamaguchi This talk is based on arXiv:

Mar. 29, 2008 LHC 研究会 Contents 1.Introduction 2.The model 3.The problem 4.Cosmology 5.Summary

Mar. 29, 2008 LHC 研究会 1. Introduction SUSY is the good candidate for new physics beyond SM solve the hierarchy problem has DM candidates However, sparticles have not been discovered yet It has to be broken Phenomenological aspects depend on how SUSY is broken To understand the SUSY mechanism is important !

Mar. 29, 2008 LHC 研究会 The moduli mediationThe anomaly mediation In KKLT set-up, the modulus is stabilized with the relatively heavy mass : modulus mass Thus, the anomaly mediation is comparable to the modulus one This is known as the mirage mediation Choi et. al. ’05 Endo, Yamaguchi, Yoshioka ’05 The mirage mediation is one of most plausible mediation mechanisms

Mar. 29, 2008 LHC 研究会 The mirage mediation is very attractive mechanism However, it has two crucial problems In general, B parameter becomes TeV Too large ! 2. moduli problem The modulus decay produces too many gravitinos Neutralinos, if they are stable, overclose the Universe ! Endo, Hamaguchi, Takahashi ’06 SN, Yamaguchi ’06 Choi, Jeong, Okumura ’05 1. problem

Mar. 29, 2008 LHC 研究会 We showed to introduce the axion superfield into the mirage mediation can solve moduli problem as well as DM strong CP problem SUSY CP problem axino MeV problem

Mar. 29, 2008 LHC 研究会 2. The model Let us consider the following superpotential : axion superfield: messenger The scalar potential of S is From RGE of, S is stabilized at some scale

Mar. 29, 2008 LHC 研究会 The PQ scale in axionic mirage mediation In what follows, we consider the case

Mar. 29, 2008 LHC 研究会 The axino mass is : anomalous dimension of S This is two-loop order in contrast with the other soft masses being one-loop The axino becomes LSP

Mar. 29, 2008 LHC 研究会 Let us consider the following superpotential and Kahler potential are singlets When gets VEV, we can integrate out 3. The problem

Mar. 29, 2008 LHC 研究会 4. Cosmology We assume both and have Planck scale amp., and their coherent oscillations start before the reheating is completed for The modulus decay dilutes unwanted particles saxion mainly decays into axions for modulus mainly decays into gauge multiplet

Mar. 29, 2008 LHC 研究会 Axino are produced by non-thermally from the modulus This process gives the dominant contribution Table of the abundance of the axino in the 4th. process

Mar. 29, 2008 LHC 研究会 Contours of the density parameter of the axino Case ACase B

Mar. 29, 2008 LHC 研究会 Especially, the higgsino NLSP case is very interesting ! The higgsino can decay into the Higgs and the axino through the term also decay into the Z boson through the higgsino-axino mixing The lifetime of the higgsino is for

Mar. 29, 2008 LHC 研究会 5. Summary We discussed the axionic extended mirage mediation, axionic mirage mediation In this model, the axino is LSP, which is much lighter than the neutralinos no moduli problem also SUSY CP problem axino with MeV can explain DM The problem can be solved Its collider signature is very interesting