Dirac gaugino as leptophilic dark matter Based on : JCAP 02 (2010) - PowerPoint PPT Presentation

Dirac gaugino as leptophilic dark matter Based on : JCAP 02 (2010) 015 In collaboration with E. J. Chun and S. Scopel Park, Jong-Chul KIAS PHENO 2010 Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 1 / 14

1 Motivation 2 Dirac gaugino 3 Analysis 4 Conclusion Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 2 / 14

Cosmic ray observations P.F. Yin et al., PRD 79 , 023512 (2009) [Fermi/LAT] PRL 102 , 181101 (2009) Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 3 / 14

Candidates of e + & e − source Nearby mature pulsars: Neither too far & young, nor old D. Hooper et al., JCAP 01 , 025 (2009); S. Profumo, arXiv:0812.4457 [astro-ph] Supernova remnants N. J. Shaviv et al., PRL 103 , 111302 (2009) Dark matter decay: Required lifetime ∼ O (10 26 s ) Dark matter annihilation � σ v � Relic ∼ 10 2 � � 2 � σ v � Gal M DM 1 500 GeV Excesses in e + & e − but not in p − → Majorana neutralino disfavored: 2 � σ v � χχ → f f is suppressed by m 2 f / m 2 χ due to helicity flip. Dirac gaugino No m 2 f / m 2 χ suppression 1 A potentially sizable σ SI from χγ µ χ Z µ 2 Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 4 / 14

Gaugino-Higgsino masses Extended R-symmetric gauge-Higgs sector √ W ′ = µ 1 H d R u + µ 2 R d H u − 2 g a ( ξ 1 H d T a R u + ξ 2 H u T a R d ) Φ a Φ a = ( φ a , ψ a ): N=2 counterpart of the gauge superfield W a α Dirac gaugino mass & extended µ term α Q α Φ a � � F or HRX † � � � � XW a F , HR Φ D , Neutralino mass matrix in the ( ψ 0 , ˜ B , ˜ H d , ˜ R u , ˜ H u , ˜ R d ) basis   0 0 − ξ 1 m Z s W c β 0 ξ 2 m Z s W s β M 1 − m Z s W c β  M 1 0 0 m Z s W s β 0    0 − m Z s W c β 0 µ 1 0 0   M =   − ξ 1 m Z s W c β  0 µ 1 0 0 0    0 m Z s W s β 0 0 0 µ 2 ξ 2 m Z s W s β 0 0 0 µ 2 0 Diagonalization M diag = N T MN Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 5 / 14

Diagonalization matrix 6 rotation angles vanish in the limit | µ 1 , 2 | ≫ M 1 > M Z where N ≃ 1. Mass matrix in the Dirac basis Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 6 / 14

Interaction vertices √ √ 2 g ′ Y f R N 22 [ f P L χ � f R + χ P R f � f ∗ 2 g ′ Y f L N 22 [ f P R χ c � f L + χ c P L f � f ∗ L f = R ] + L ] , g ′ 2 h 0 [ C 1 ( ψ H 1 P R χ c + χ c P L ψ H 1 ) + C 2 ( ψ H 2 P R χ c + χ c P L ψ H 2 ) L h 0 = 1 ( ψ H 1 P L χ c + χ c P R ψ H 1 ) + C ′ 2 ( ψ H 2 P L χ c + χ c P R ψ H 2 ) + C ′ + 2 δ S χχ ] , g 1 ( ψ H 1 γ µ P L χ c + χ c γ µ P L ψ H 1 ) + δ 1 ( ψ H 1 γ µ P R χ c + χ c γ µ P R ψ H 1 ) Z µ [ δ ′ L Z = 2 c W 2 ( ψ H 2 γ µ P L χ c + χ c γ µ P L ψ H 2 ) + δ 2 ( ψ H 2 γ µ P R χ c + χ c γ µ P R ψ H 2 ) + δ ′ + δ 2 V χγ µ χ + δ 2 A χγ µ γ 5 χ ] , where C 1 = s α N 22 N 33 + c α N 22 N 53 , C 2 = c α N 22 N 55 + s α N 22 N 35 , C ′ C ′ 1 = ξ 1 s α N 11 N 44 + ξ 2 c α N 11 N 64 , 2 = ξ 2 c α N 11 N 66 + ξ 1 s α N 11 N 46 , δ j ( N kl ) ∝ s i ∝ m Z / | µ 1 , 2 | . Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 7 / 14

Annihilation channels & direct detection Dominant annihilation channels m 2 � σ v � ll ≃ 2 πα 2 Y 4 χ c 4 ( m 2 l l + m 2 χ ) 2 W � χχ → h → f f , hZ , W + W − & χχ → ψ H i → 2 h : suppressed by δ 2 S v 2 or v 2 Direct detection Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 8 / 14

Constraints on � σ v � Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 9 / 14

Diffuse γ − ray by IC scattering m χ =200, 500, 1000, 1135, 1500, 2000 GeV Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 10 / 14

Parameter space Dashed line: boost factor = 10 Dotted lines: σ SI /σ CDMSII = 1 , 10 − 3 , 10 − 5 (from lower curve) Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 11 / 14

Various observables for m χ = 465 GeV Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 12 / 14

Conclusion Leptonic excesses in cosmic rays may reveal the identity of DM. − → Require brand new ideas? Dirac gauginos can be natural realizations of leptophilic DM . Light ( m χ � 500 GeV) DG can explain the PAMELA data with moderate or no boost factor for light ( � m χ ) slepton masses. DG with a non-vanishing Higgsino fraction can have a vector coupling with the Z boson. − → Sizable σ SI Present constraints on the Higgsino fraction of DG from direct searches are at the same level of those coming from antiproton data. − → DG signal is potentially at the level of the sensitivity of direct detection experiments at present and in the near future. Determining the Majorana/Dirac nature of gauginos will be an interesting task for future experiments to look for SUSY. Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 13 / 14

Thank You! Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 14 / 14

Boost factors for the democratical annihilation case Solid: boost factors, dashed: Ω min h 2 / Ω DG h 2 , thin: m l / m χ = 1, thick: m l / m χ = 2, | µ | ≫ M 1 � � Park, Jong-Chul (KIAS) Dirac gaugino as leptophilic dark matter PHENO 2010 15 / 14