EWIMP dark matter detections EWIMP dark matter detections Shigeki - PowerPoint PPT Presentation

EWIMP dark matter detections EWIMP dark matter detections Shigeki Matsumoto Shigeki Matsumoto HIGH ENERGY ACCELERATOR RESEARCH HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION (KEK) ORGANIZATION (KEK) Collaborated with Collaborated with Junji Hisano (ICRR, University of Tokyo) Junji Hisano (ICRR, University of Tokyo) Mihoko Nojiri ( YITP, Kyoto University ) Mihoko Nojiri ( YITP, Kyoto University ) Osamu Saito (ICRR, University of Tokyo) Osamu Saito (ICRR, University of Tokyo) Phys. Rev. D71: 063528, 2005 Phys. Rev. Lett. : 92: 031303, 2004 Phys. Rev. D67: 075014, 2003

Dark Matter Abundance Dark Matter Abundance Results from recent cosmological observation Mean density of matter and baryon Mean density of matter and baryon − ρ ≈ × 6 2 . 9 1 0 G e V / c c M ρ ≈ × - 7 4 . 6 1 0 G e V / c c B Existence of non-baryonic (cold) dark matter Existence of non-baryonic (cold) dark matter = Beyond SM Physics Constituent of dark matter Beyond SM Physics Constituent of dark matter

EWIMP Dark Matter EWIMP Dark Matter We consider non-singlet dark matter SU (2) L We consider non-singlet dark matter (a neutral component of multiplet) SU (2) L (a neutral component of multiplet) Electroweak charged WIMP = EWIMP Electroweak charged WIMP = EWIMP Concrete example - partner Concrete example SU (2) L Neutralino in Minimal SUSY SM Neutralino in Minimal SUSY SM W,Z g � � � � χ = + + + � 0 Z B Z W Z H Z H 01 02 03 d 04 u χ � 0 Triplet Doublet We focus on signatures in EWIMP dark matter detections. We focus on signatures in EWIMP dark matter detections. + γ , e ( Direct detection , Indirect detection using ) ( Direct detection , Indirect detection using ) Interesting phenomena occur in these detections !! Interesting phenomena occur in these detections !!

Direct detection for EWIMP dark matter Direct detection for EWIMP dark matter χ � 0 Nuclear recoil after E EWIMP-nucleus scattering q If the EWIMP mass is large enough, If the EWIMP mass is large enough, the cross section at tree level is suppressed by new physics scale the cross section at tree level is suppressed by new physics scale Diagrams for Spin-independent Int. χ � 0 Triplet EWIM (Wino-like dark matter) χ � 0 ~ q − 2 ⎛ ⎞ μ h, H 2 − σ × ×⎜ ∼ 43 2 ⎟ 3 10 cm q × SI ⎝ ⎠ 100 GeV M q 2 gaugino-higgsino squark mass mixing

Non-decoupling interaction at 1-loop level Non-decoupling interaction at 1-loop level At 1-loop level, there are some diagrams At 1-loop level, there are some diagrams not suppressed by new physics scale. not suppressed by new physics scale. χ χ � � 0 0 W W W W h, H q q q’ Intermediate chargino particle in these diagrams are almost On-shell. Intermediate chargino particle in these diagrams are almost On-shell. There are no suppression at each vertex in these diagrams. There are no suppression at each vertex in these diagrams. In the extremely heavy EWIMP case, the 1-loop diagrams In the extremely heavy EWIMP case, the 1-loop diagrams are larger than diagrams at tree level !! are larger than diagrams at tree level !! The 1-loop diagrams give the lower limit of the collision cross section. The 1-loop diagrams give the lower limit of the collision cross section.

EWIMP-Nucleon cross section including 1-loop diag. EWIMP-Nucleon cross section including 1-loop diag. − × 47 2 Cross section ( 10 cm ) m = 200 GeV (Triplet) tan β = 4 tan β = 4 tan β = 40 tan β = 40 The cross section for the EWIMP receives the sizable 1-loop The cross section for the EWIMP receives the sizable 1-loop correction, when the cross section is smaller than about 10 -45 cm 2. correction, when the cross section is smaller than about 10 -45 cm 2.

Indirect detection of EWIMP dark matter using γ -rays Indirect detection of EWIMP dark matter using γ -rays Annihilate γ γ - ray π 0 χ � 0 γ W + χ � 0 W − Sun Halo Calculation of annihilation cross sections is important!! Calculation of annihilation cross sections is important!! > m m When , usual perturbation can not be applied When , usual perturbation can not be applied W due to the threshold singularity !! due to the threshold singularity !!

Breakdown of perturbation in cal. of cross section Breakdown of perturbation in cal. of cross section χ � 0 W + W or Z W or Z + + + Z ● ● ● χ � 0 W − α α m 2 2 m α 2 A ~ ~ A m 2 ~ A 0 2 0 0 2 m W W Ladder diagram α m m / Diagrams have an additional factor for each weak gauge boson exchange. 2 W Intermediate states 1.Velocity of We have to resum − � 3 v 10 c (EWIMP& partner) are EWIMP: ladder diagrams!! almost on-shell. 2. Degeneracy between Non-pertuvative effect Threshold Singularity EWIMP & partner We performed Bound states composed Annihilation cross We performed Bound states composed Annihilation cross the resummation by EWIMP & Partner’s pair section is enhanced the resummation by EWIMP & Partner’s pair section is enhanced using NR-Lagrangian. appear if m > m W !! compared to leadings. using NR-Lagrangian. appear if m > m W !! compared to leadings.

Annihilation cross section including effects of T.S. Annihilation cross section including effects of T.S. − + − σ χ χ → � � 3 1 0 0 v cm ( sec ) for W W δ = m 0.1( GeV ) Triplet δ = Doulet m 1( GeV ) − = 3 v c / 10 Leading order cal. Gamma ray flux is increased For example Models of particle physics Constraint on MSSM parameters by Models of particle physics Constraint on MSSM parameters by can be constrained by the gamma rays (1-10GeV) from the galactic can be constrained by the gamma rays (1-10GeV) from the galactic observation !! center using EGRET observation . observation !! center using EGRET observation .

Gamma ray signal from EWIMP annihilation in galactic cneter Gamma ray signal from EWIMP annihilation in galactic cneter Ψ ⎛ ⎞ < σ > 2 i ⎛ ⎞ d ( ) E dN v 1 TeV γ γ − − − = × ∑ ΔΩ 14 2 1 i ⎜ ⎟⎜ ⎟ 9.3 10 ( ) cm s J − − ⎝ ⎠ 27 3 1 ⎝ ⎠ dE dE 10 cm s m i 2 ⎛ ρ ⎞ 1 ∫ ∫ = Ω θ ⎜ ⎟ J d dl ( ) − ΔΩ 3 ΔΩ ⎝ ⎠ 8.5 ( kpc ) 0.3 GeV cm l o s . . Flux strongly depends on dark matter profile, so evaluation of the profile is important !! Cuspy structure ρ ( ) r − α ρ � ∼ ( ) r r ( r 0) ( Moore: α = 1.4 ) Recent N-body ( NFW: α = 1 ) Simulations suggest ( King: α = 0 )

Excluded region by EGRET from G.C. for different profiles

Indirect detection of EWIMP dark matter using positrons Indirect detection of EWIMP dark matter using positrons Positron Fraction = (Positron Flux) / (Positron + Electron Flux) Background Large excess of the positron fraction !! Large excess of the positron fraction !!

Summary We computed the cross sections of dark matter relevant to direct and SU (2) L indirect detections when the DM is non-singlet (EWIMP). We calculated the collision cross section between EWIMP and nucleus, gamma ray flux from the galactic center, positron excess in C.R.. > ( m m ) When the mass of EWIMP is large , some 1-loop diagrams W significantly contribute to the collision cross section (Non-decoupling). In cal. of the annihilation cross section, non-perturbative effects become important, and the cross section is enhanced (Threshold Singularity). If EWIMP is realized as the dark matter, strong signals are expected in both direct and indirect detections. In direct detections, EWIMP has the collision cross section larger than 10 -46 cm 2 for the triplet, and 10 -47 cm 2 for the doublet case. In indirect detections, strong signals such as excesses of gamma rays and positrons in C.R. are expected. Some regions in MSSM parameter space are already constrained by the EGRET observation.