Wino DM Constraints from γ-ray Obs of dSphs

Koji Ichikawa with

B. Bhattacherjee (IPMU), M. Ibe (IPMU & ICRR), S. Matsumoto (IPMU) and K. Nishiyama (IPMU)

(JHEP 07(2014)080 [arXiv: 1405.4914])

PPP2014, Kyoto, Japan, July 2014 1

• Introduction – Indirect Detection – Dwarf Spheroidal Galaxies – Case Study: Wino DM

• Analysis – Signal Flux – Background Flux – Detector Capabilities

• Result – Future Sensitivity Line

• Summary

Outline

2

• Introduction – Indirect Detection – Dwarf Spheroidal Galaxies – Case Study: Wino DM

• Analysis – Signal Flux – Background Flux – Detector Capabilities

• Result – Future Sensitivity Line

• Summary

Outline

3

DM

DM

SM

SM

Indirect Detection

Collider Production

Dir

ect

Det

ecti

on

Dark Matter Search

4

5

Signal Target

Milky-Way Galaxy

Charged CRs

Cluster

～100 kpc

～100 Mpc

～8.5 kpc

dSphs

Cluster

6

Signal Target

Milky-Way Galaxy

Charged CRs

～100 kpc

～100 Mpc

～8.5 kpc

dSphs

Profile?

Substructure?

Propagation?

Robust!

Dwarf spheroidal galaxies

dSphs: 1. Neighbor galaxies: 10~100kpc 2. Large Mass to Luminosity ratio = DM rich 3. Fewer gas containment

7

Classical

Ultra-faint

SDSS-II

Dwarf spheroidal galaxies

dSphs: 1. Neighbor galaxies: 10~100kpc 2. Large Mass to Luminosity ratio = DM rich 3. Fewer gas containment

8

Classical

Ultra-faint

SDSS-II

Case Study: Wino DM

● Higgs UV divergence

● Dark matter candidates

● Gauge Unification

Heavy sfermion + (relatively) light DM seems to be favored…

AMSB

SUSY

Wino DM

A. Higgs Radiative Correction B. DM Relic Abundance

9

● Collider: LHC bound

● DM relic abundance

● Astro:

(M. Ibe, et al, PLB709, 2012)

Wino DM: Current observational limit

(ATLAS 95% C.L)

γ-ray observation from the milky way satellite galaxies (Fermi-LAT 95% C.L)

ATLAS arXiv:1310.3675 Data: Fermi-LAT arXiv:1310.0828

GeV 320MWino

TeV 9.2MWino

GeV 270MWino

10

1. What will the future exclusion region be like?

2. What should we do to improve the sensitivity line efficiently?

Questions…

?

11

• Introduction – Indirect Detection – Dwarf Spheroidal Galaxies – Case Study: Wino DM

• Analysis – Signal Flux – Background Flux – Detector Capabilities

• Result – Future Sensitivity Line

• Summary

Outline

12

Energy Bin

Signal Flux: F(S)

BG Flux: F(B)

Observed Events

Particle Factor Astrophysical Factor

Galactic Diffuse Isotropic Diffuse Point-like Source

a: dSph i: Energy Bin

Signal:

Background:

ROI Effective Area

dSph “a”

ΔΩ

Detector: Aeff

Signal γ BG γ

13

Particle Physics Factor Astrophysics Factor (J-factor) ZZZWWf ,,,

Hryczuk and Iengo (2012) Cirelli et al (2012)

Signal Flux

Error: 1-10 % level

Large uncertainty: Next Slide

14

Astrophysical Factor DM Density profile

(obs) 2

l.o.sJeans equation for stars

(Theory) 2

l.o.s

21 )/1()/( sss rrrr

21 )/1()/1( sss rrrr

Cusp

Cored

Fit

Classical: Well-determined

Ultra-faint: Not well-determined. Prior dependence

Stellar Density Profile: ν(r)

15

Astrophysical Factor DM Density profile

(obs) 2

l.o.sJeans equation for stars

(Theory) 2

l.o.s

21 )/1()/( sss rrrr

21 )/1()/1( sss rrrr

Cusp

Cored

Fit

Classical: Well-determined

Ultra-faint: Not well-determined. Prior dependence

Stellar Density Profile: ν(r)

16

Background Flux 1. Galactic Diffuse

CR + ISM, Brems of CRe, IC (CRe + Interstellar radiation field) → Simulation (e.g. GALPROP) with ISM, ISRF, Large Scale Structure.

2. Isotropic Diffuse AGN, Starburst, γ-Ray burst, unknown sources → Evaluated from |b| > 30⁰ sky data

3. Point-like Source AGN, SNR, Pulsars, Unidentified → Mask/Model

17

18

Detector Capabilities

Aeff

PSF

ROI

ROI:

Typical dSphs Size PSF (68 % containment angle) Signal Flux

Background Flux

PSF effect -> efficiency ε

Large ΔΩ -> Large Background

Satellite- type Obs

Efficiency: ε

Direction Reconstruction

Sensitivity Line Profile Likelihood J-factor error is included

Test (95% C.L)

2000 Pseudo Experiments for Nai ({N(1)

ai, N(2)

ai,N(3)

ai…}) (Poisson with the mean of Bai)

Each N(i)ai → 〈σv〉(i)

Right Figure: Mean and 68 (95) % band for the set {〈σv〉(1) , 〈σv〉(2), 〈σv〉(3),… }

P(N:λ): Poisson G(x: μ, σ): Log Gaussian Nai: Observed Events

19

• Introduction – Indirect Detection – Dwarf Spheroidal Galaxies – Case Study: Wino DM

• Analysis – Signal Flux – Background Flux – Detector Capabilities

• Result – Future Sensitivity Line

• Summary

Outline

20

21

Current Limit Future Prospects

Ursa Minor 320 GeV ≤ m ≤ 2.25TeV and 2.43 TeV ≤ m Combined (15 dSphs) <- Aggressive 390 GeV ≤ m ≤ 2.14TeV and 2.53 TeV ≤ m

810 GeV ≤ m ≤ 1.86TeV, 2.70 TeV ≤ m

• Indirect detection is essential for the heavy DM search.

• Gamma-ray observation of dSph can give robust constraints on the DM annihilation cross section.

• Investigation of Ultra-faint’s stellar kinematics dramatically affects the sensitivity lines.

22

Summary

23

Cirelli et al:1407.7058

Summary

24

Summary

dSph γ-Continuum 10 yrs

Cirelli et al:1407.7058

Thank you!

Koji Ichikawa with

B. Bhattacherjee (IPMU), M. Ibe (IPMU & ICRR), S. Matsumoto (IPMU) and K. Nishiyama (IPMU)

(JHEP 07(2014)080 [arXiv: 1405.4914])

PPP2014, Kyoto, Japan, July 2014 25