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2006.7.31-8.3 素粒子物理学の進展 2006@ 基研. Analysis of supersymmetric extra U(1) models from CDM. Kanazawa univ. Institute for Theoretical Physics Satoshi Nakamura collaborate with Daijiro Suematsu. Phys.Rev.D73 035010,2006 [hep-ph/0511299] hep-ph/0609061. Introduction. Background of this study.
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2006.7.31-8.3 素粒子物理学の進展2006@基研 Analysis of supersymmetricextra U(1) models from CDM Kanazawa univ. Institute for Theoretical Physics Satoshi Nakamura collaborate with Daijiro Suematsu • Phys.Rev.D73 035010,2006 [hep-ph/0511299] • hep-ph/0609061
Introduction Background of this study SUSY is the best motivative expansion of SM, ex. ・solution for hierarchy problem ・gauge coupling unification ・including CDM candidate and it’s going to be checked at LHC. But MSSM has a few problem, ex. ・little hierarchy problem ・μ-problem so let’s study a realistic model which can solve these problems. Subjects of this talk Supersymmetric extra U(1) model gives a solution for μ-problem. MSSM : Neutralino components U(1) model: so we study a realistic U(1) model which can solve DM problem Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
Contents • μ problem • extra U(1) model • CDM in U(1) model • Analysis Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
1-1 μ-problem - MSSM μ problem mass dim. = 0 mass dim. = 1 (MSSM Super potential) cutoff scale soft mass, gaugino mass SUSY MSSM doesn't completely solve hierarchy problem in SM. = μproblem Other terms are trilinear but only μterm is quadratic Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
1-2 μ-problem - NMSSM NMSSM A naive ideal solution for μ-problem is to introduce an extra singlet chiral superfield S and induces cutoff scale by SUSY extra symmetry? Extra constraint is required to exclude μterm, example: global U(1) symmetry (similar to baryon number) Pecci-Quinn symmetry but S has non-zero VEV so appears a massless NG boson Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
Ⅰ Ⅱ Ⅲ 1-3 μ-problem - Z3 model MSSM + Z3 introduce extra discrete symmetry Z3 Domain wall problem Domain wall which corresponds to VEVs gapmust appear in the universe S has non-zero VEVs energy gap Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
1-4 μ-problem - U(1) model U(1) model Extra symmetry must be local & continuous so U(1) gauge symmetry is the simplest symmetry U(1) model = MSSM + singlet chiral superfield S + extra U(1) gauge symmetry Extra U(1) model gives a complete solution for μ problem ! Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
2-1. extra U(1) model extra U(1) model = MSSM + U(1)’ + singlet S Covariant derivative Super potential VEV New interactions Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
2-2. Neutral gauge boson in U(1) model Neutral gauge boson・・・ MSSM + 1 component ・・・heavy Z’ Z-Z’ mixing angle or ・・・light Z’ assumption Z’ decay to dilepton Z’mass lower bound Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
2-2. Neutral gauge boson in U(1) model Z’ dilepton decay branching fraction @CDF Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
2-3. Neutral Higgs in U(1) model NeutralHiggs(CP-even) ・・・ MSSM+1 component Higgs mass upper bound MSSM NMSSM extra U(1) Z’ mass upper bound Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
2-3. Neutral Higgs in U(1) model Higgs mass Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
2-4 Charge assignment extra U(1) charge We consider extra U(1)s which are derived from E6 anomaly cancellation Z’ charge is defined as linear combinations of these U(1) charges Charge is determined only by θ tanβ tanβ depends on θ Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
2-4 Charge assignment extra U(1) charge Particles Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
2-4 Charge assignment Higgs charge, tanβ 5 1.2 1.0 0.8 4 0.6 0.4 3 0.2 charge 0.0 -0.2 2 -0.4 -0.6 1 -0.8 -1.0 0 -1.2 -7 -6 -5 -4 -3 -2 -1 0 Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
2-5 Higgs potential Soft mass(higgs sector) Fixed charge determines higgs potential, so stational conditions determine higgs soft mass. Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
2-6 Neutralinos in U(1) model Neutralinos mass matrix diagonalize singlino Lightest Neutralino(LN) ・・・ CDM candidate (when R-parity is introduced) Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
3-1 CDM relic abundance Observation 74% 22% Dark Energy Dark Matter Baryon 4% Cosmic energy composition CMB anisotropy observed by WMAP Theoretical estimation Boltzmann distribution Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
3-2 CDM candidate in MSSM Neutralinos Annihilation process Other contribution If LN is degenerate with NLSP (ex. stau), coannihilation process is effective. Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
3-3 WMAP allowed region in cMSSM T.Nihei et.al (JHEP0207) coannilation with stau Too much CDM Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
3-4 Annihilation process in U(1) model Z’ exchange When LN dominated by Singlino, this contribution is larger. Neutral Higgs exchange When pole enhancement realizes, this contribution is larger. Z boson exchange This contribution is the same as MSSM. Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
3-5 Singlino dominated Lightest Neutralino Neutralino mass matrix Huge Large Large diagonalization Lightest Neutralino(LN) singlino CDM candidate Analogy of Sea-saw mechanism D.Suematsu Phys.Rev.D73 035010 S.N., D.Suematsu hep-ph0609061 Singlino dominated lightest neutralino =CDM candidate is different from MSSM Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
3-5 Singlino dominated Lightest Neutralino Lightest Neutralino state Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
3-6 Non-universal Aberian gaugino mass D.Suematsu Phys.Rev.D73 035010,2006 hidden observable Field strength is gauge invariant itself. This transformation can resolve kinetic mixing Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
4-1 Parameters Parameters in this model • gauge coupling impose unification relation represent a freedom of μ • coupling constant • Soft mass impose universality conditions and assume to be 1TeV • gaugino mas impose universality conditions only for Mw and My Free parameters are Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
4-2 WMAP allowed region Parameter set ① Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
4-3 WMAP allowed region – Mx dependence WMAP Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
4-4 WMAP allowed region – mz’ dependence WMAP Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
4-5 WMAP allowed region② Parameter set ② Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
4-6 Other constraints Phenomenological constraints Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
4-7 allowed region Parameter set ① Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
4-8 allowed region② Parameter set ③ Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
4-9 Final result Z’ Higgs Neutralino Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
4-10 Prediction Integrated luminosity @ LHC Z’ decay cross section@LHC (√s=14TeV) We can expect event ! large LN mass small LN mass Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura
Summary Summary ・To introduce extra U(1) gauge symmetry gives a solution for μ-problem ・Singlino dominated Lightest Neutralino appears in huge Mx regions ・WMAP allowed regions appear in the places where Singlino dominated LN is realized → CDM=Singlino ・Singlino-Z’ interaction with large Qs is important in WMAP allowed regions ・If this model is right, Z’ decay event may be observed at LHC Next subjects ・We will analyze the model using a concrete SUSY breaking mechanism ・direct, indirect detection Kanazawa univ. Institute for Theoretical Physics, Satoshi Nakamura