Dark Matter Annihilation, Cosmic Rays and Big-Bang Nucleosynthesis

Dark Matter Annihilation, Cosmic Rays and Big-Bang Nucleosynthesis Institute for Cosmic Ray Research, University of Tokyo Kazunori Nakayama J.Hisano, M.Kawasaki, K.Kohri and KN, arxiv:0810.1892 J.Hisano, M.Kawasaki, K.Kohri and KN, arxiv:0812.0219 J.Hisano, M.Kawasaki, K.Kohri, T.Moroi and KN, arxiv:0901.3582 KEKPH09 @ KEK (2009/03/06)

Energy content of the Universe after WMAP What is the dark matter? Can it be detected? Direct detection Indirect detection DM-nucleon Scattering DM annihilation Cosmic Ray Signals

PAMELA observation )) - )+!(e + ) / (!(e +!(e 0.3 0.2 0.1 Positron excess Positron fraction 0.02 PAMELA Expected Background 0.01 1 10 100 Energy (GeV) excess in cosmic-ray positron flux Adriani et al.,arxiv:0810.4995

ATIC/PPB-BETS observations 1,000 excess in electron+positron flux E e 3.0 dn/dee (m 2 s 1 sr 1 GeV 2 ) 100 10 ATIC BETS, PPB-BETS HEAT AMS 10 100 1,000 Energy (GeV) J.Chang et al. Nature (2008)

From SPIRES database (2009/2/11) 5) Observation of an anomalous positron abundance in the cosmic radiation. O. Adriani et al. Oct 2008. 20pp. Temporary entry e-print: arxiv:0810.4995 [astro-ph] TOPCITE = 50+ References LaTeX(US) LaTeX(EU) Harvmac BibTeX Keywords Cited 104 times Abstract and Postscript and PDF from arxiv.org (mirrors: au br cn de es fr il in it jp kr ru tw uk za aps lanl ) Bookmarkable link to this information

Decay or Annihilate Decaying DM DM need not be completely stable. DM lifetime with can explain PAMELA. Annihilating DM τ 10 26 sec Flux n DM τ 10 29 cm 3 s 1 DM has weak scale annihilation cross section. Cross section with σv 10 24 10 23 cm 3 s 1 can explain PAMELA. Flux n 2 DM σv 10 29 cm 3 s 1

Dark matter annihilation in the Galaxy now Positron, Gamma-ray, Neutrinos,...

Dark matter annihilation in the early Universe Effects on Big-Bang Nucleosynthesis Dark matter annihilation in the Galaxy now Positron, Gamma-ray, Neutrinos,...

This talk DM annihilation as explanation for PAMELA/ATIC. Implications on other signatures of DM annihilation in a model-independent way. Gamma-Ray Flux Neutrino Flux Effects on Big-Bang Nucleosynthesis

Positron Flux

Positron from DM Annihilation Kamionkowski,Turner(91), Baltz,Edjso(98),... χχ W + W, b b, l + l,... e ±, γ, p, ν,... Energy loss due to synchrotron radiation and inverse Compton with CMB and star light. High-Energy positron can reach to the Earth within a few kpc. L Positron flux is not so sensitive to diffusion zone L and halo density profile.

Propagation of positrons in Galaxy Diffusion Equation Φ t = K(E) 2 Φ(E) + E [b(e)φ(e)] + Q(E) Diffusion Energy loss DM annihilation e + r K(E) 3 10 27 cm 2 s 1 (E/1GeV) 0.6 b(e) 10 16 GeVs 1 (E/1GeV) 2 Typical propagation distance w/o energy loss r 1 kpc(100gev/e) 0.2

Positron fraction Total flux [GeV 2 m 2 s 1 sr 1 ] 10 3 L=4kpc χχ e + e : m χ = 650GeV, σv = 5 10 24 cm 3 s 1 χχ µ + µ : m χ = 900GeV, σv = 15 10 24 cm 3 s 1 J.Hisano, M.Kawasaki, K.Kohri, T.Moroi and KN, 0901.3582.

Positron fraction Total flux [GeV 2 m 2 s 1 sr 1 ] 10 3 L=1kpc χχ τ + τ : m χ = 1TeV, σv = 4 10 23 cm 3 s 1 χχ W + W : m χ = 800GeV, σv = 3 10 23 cm 3 s 1 J.Hisano, M.Kawasaki, K.Kohri, T.Moroi and KN, 0901.3582.

Gamma-Ray Flux

Gamma-ray from DM Annihilation Bergstrom, Ullio, Buckley(98),... γ Gamma-ray comes from DM annihilation at the Galactic center Flux: Φ γ (ψ, E) σv 8πm 2 DM dn γ de l.o.s. ρ 2 (l)dl(ψ)

Gamma-ray from DM Annihilation Bergstrom, Ullio, Buckley(98),... γ Gamma-ray comes from DM annihilation at the Galactic center Flux: Φ γ (ψ, E) σv 8πm 2 DM dn γ de l.o.s. ρ 2 (l)dl(ψ) Particle physics model

Gamma-ray from DM Annihilation Bergstrom, Ullio, Buckley(98),... Flux: Φ γ (ψ, E) γ σv 8πm 2 DM Gamma-ray comes from DM annihilation at the Galactic center dn γ de Orders of magnitude uncertainty l.o.s. ρ 2 (l)dl(ψ) Particle physics model DM density profile

Continuum Gamma-Rays from DM ann. Internal Brems. Final state charged particle always emit photon. χχ l + l χχ l + l γ χ χ e + e γ Cascade decay χχ τ + τ, W + W hadrons(π ±, π 0, ρ,... ) 2γ

Gamma-Ray Flux from GC Halo profile NFW ρ ρ 0 r(1 + r) 2 Isothermal ρ ρ 0 1 + r 2 r = r/r 0

Gamma-Ray Flux from GC Halo profile NFW ρ ρ 0 r(1 + r) 2 Too large Gamma flux for NFW profile. More moderate profile is OK. Isothermal ρ ρ 0 1 + r 2 r = r/r 0

Neutrino Flux

Neutrino Signal from DM Annihilation χχ W + W, b b, l + l,... e ±, γ, p, ν,... Ritz, Seckel (88),Kamionkowski (90),... Beacom, Bell, Mack (07) Interaction inside the Earth ν detector µ from GC Earth Search for up-going muons Limits from Super-K

Limits from SK : DM annihilation which can explain ATIC must not produce neutrinos with same rate. Annihilate into left handed leptons Annihilate into right handed leptons (ν ν + l L l+ R ) (l R l+ L ) J.Hisano, M.Kawasaki, K.Kohri, KN (2008)

Effects on BBN

Effects of DM Annihilation on BBN Even after freezeout, DM still annihilates each other and injects high-energy particles. Jedamzik (2004) Hisano,Kawasaki,Kohri,KN(2008) Destruction/production of light elements 4 He, 3 He, D, 6 Li, 7 Li Observations of light elements 4 He, 3 He, D, 6 Li, 7 Li BBN gives constraints on DM annihilation rate

χχ W + W, l + l hadrons, radiation Destruction/production of light elements D, 3He production p(n, γ) + α BG D, T, 3 He,... 6Li Production p(n, γ) + α BG T, 3 He,... T( 3 He) + α BG n(p) + 6 Li 6Li production and many other processes... 4 He, 3 He, D, 6 Li, 7 Li

Constraint on Leptonic DM annihilation χχ l + l J.Hisano, M.Kawasaki, K.Kohri, T.Moroi and KN, 0901.3582.

Constraint on Leptonic DM annihilation χχ l + l PAMELA/ATIC region J.Hisano, M.Kawasaki, K.Kohri, T.Moroi and KN, 0901.3582.

Constraint on hadronic DM annihilation χχ W + W J.Hisano, M.Kawasaki, K.Kohri, T.Moroi and KN, 0901.3582.

Constraint on hadronic DM annihilation χχ W + W PAMELA/ATIC region J.Hisano, M.Kawasaki, K.Kohri, T.Moroi and KN, 0901.3582.

Summary Signatures of DM annihilation which explain PAMELA/ATIC w/o boost factor Gamma-ray Flux Neutrino Flux Effects on BBN NFW is not favored. χχ ν ν should be suppressed. Hadronic ann. is not favored. Constraints on DM model, or may be another hint for DM annihilation.

ν µ µ ν µ µ Cross section for σ (µ) ν G2 F s π s = 2m N E ν W N N Muon energy loss de dx = a be Ionization loss : a 2 MeVcm 2 g 1 Pair production, brems,... : b 10 6 cm 2 g 1 Muon range: µ Muon Flux at SK production R µ E F µ Primary Neutrino Flux de df ν de E2 de

Thermal Relic DM : σv 3 10 26 cm 3 s 1 PAMELA/ATIC : σv 10 24 10 23 cm 3 s 1 Nonthermal production of DM Introduce large boost factor B F (Clumpy DM halo) σv eff = B F σv In this talk, we assume B F = 1 (smooth DM distribution)

Nonthermal Production Decay of long-lived particle mdm Decay at Td < Tf 20 Nonthermal DM Td=10GeV Gravitino Moduli Q-Ball Saxion WMAP Kawsaki,Moroi,Yanagida(96),Moroi,Randall(00), Fujii,Hamaguchi(02),Gelmini,Gondolo(06) Kawasaki,KN(07),Nagai,KN(08),Acharya et al(08) Td=1GeV M.Nagai, KN (08)

Nonthermal Production Decay of long-lived particle mdm Decay at Td < Tf 20 Nonthermal DM Td=10GeV Gravitino Moduli Q-Ball Saxion WMAP Td=1GeV What s the implication? Kawsaki,Moroi,Yanagida(96),Moroi,Randall(00), Fujii,Hamaguchi(02),Gelmini,Gondolo(06) Kawasaki,KN(07),Nagai,KN(08),Acharya et al(08) M.Nagai, KN (08)

Anti-Proton Flux

Anti-Protons from DM Annihilation Bergstrom, Edsjo, Ullio(99), Donato et al. (01),... χχ W + W, b b, l + l,... e ±, γ, p, ν,... (m p m e ) Energy-loss is not effective. Easily escape from the diffusion zone. Anti proton flux sensitively depends on the choice of diffusion zone. L L Degeneracy between diffusion const. and L. consistent with B/C ratio. Degeneracy does not hold for DM-originated anti-proton flux.

Anti-proton flux from χχ W + W max L = 15kpc med L = 4kpc min L = 1kpc Consistent with observational data.

SUSY Neutralino?

Neutralino : Majorana fermion Annihilation into lepton pair is helicity suppressed. However, annihilation into WW is not suppressed. Wino-like neutralino : Mainly annihiltes into W boson pair. Large annihilation cross section. Naturally realized in AMSB models.

L=1kpc J.Hisano, M.Kawasaki, K.Kohri, KN (2008)

Wino with mass around 200GeV fits the PAMELA data L=1kpc J.Hisano, M.Kawasaki, K.Kohri, KN (2008)

Anti-proton flux from 200GeV Wino max L = 15kpc med L = 4kpc min L = 1kpc Consistent with observational data. See also Grajek, Kane, Phalen, Pierce, Watson, 0812.4555(2008)

W-boson injection J.Hisano, M.Kawasaki, K.Kohri, KN (2008)

200GeV Wino also solves lithium problem! W-boson injection J.Hisano, M.Kawasaki, K.Kohri, KN (2008)