1. Positron excess? Physics Department, Tohoku University Physics Department, Tohoku University （郡 和範） Kazunori Kohri － From viewpoints of both particle physics and astrophysics －

2. Positron Excess (PAMELA satellite reported) Adriani et al, arXiv:0810.4995v1 [astro-ph]arXiv:0810.4995v1

3. Electron and positron flux by Fermi Abdo et al, Fermi LAT Collaboration, arXiv:0905.0025, PRL102 (09) 181101

4. What is the origin of e + e - excess? Particle-physics origin Astrophysical origin 1.Annihilating DM 2.Decaying DM 1.Pulsars 2.Supernova Remnants (SNRs) 3.Gamma-ray burst See Fuminobu Takahashi’s talks See also Toshifumi Yamada’s and Patrick Fox’s talk See Norita Kawanaka’s talk See also Subir Sarkar’s talk See Kunihito Ioka, arXiv:0812.4851[astro-ph] or Kawanaka’s talk BBN, CMB, Gamma-ray, ν, gal. profile Diffuse-gamma-ray annisotropy B/C annisotropy

5. Another aspects of annihilating DM 1.Big Bang Nucleosynthesis (BBN) 2.Cosmic Microwave Background (CMB) 3.Gamma-ray background ( gal. and extra-gal.) 4.Neutrinos 5.…

6. http://map.gsfc.nasa.gov/media/060916 Dark Matter?

7. Thermal freezeout Boltzmann equation Ω χ does not depend on m χ Kolb & Turner Predicting TeV Physics!!!

8. Positron Excess Steady-state solution (Hisano etal, ’06) K(E) and b(E) are taken from (Baltz-Edsjo ’99) Diffusion model Flux Propagating within a few kpc, normalized to fit B/C, Boost Factor (BF) considered for clumpy distributed DM.

9. Hisano, Kawasaki, Kohri, Moroi, Nakayama (09) Positron excess in DM annihilation Diffusion model Fitted to B/C ratio

10. Hisano, Kawasaki, Kohri, Moroi, Nakayama (09) Electron/positron cutoff in DM annihilation Diffusion model Fitted to B/C ratio

11. Residual annihilation of DM even at around BBN or CMB epoch To fit the PAMELA and ATIC2/Fermi positron and electron signals, O(10 3 ) times larger than canonical value,

12. Big-Bang Nucleosynthesis (BBN)

13. Very strong cosmological tools to study long-lived particles with lifetime of 0.01 sec – 10 12 sec Theoretical predictions are constrained by observational D, 3He, 4 He, 6 Li and 7 Li abundances with their conservative errors.

14. Thermal history of the Universe Planck scale GUT phase transition? Electroweak phase transition QCD phase transition Neutrino decoupling Electron-positron annihilation Matter-radiation equality Photon decoupling (CMB) Big bang Present Inflation and Reheating Baryogenesis? Big-Bang Nucleosynthesis (BBN) cf) 1 GeV ~ 10 13 K

15. Radiation Matter Scenario of BBN Weak interaction is in equilibrium cf) 1 MeV ~ 10 10 K

16. Feezeout of weak interaction Weak interaction rate Hubble expansion rate cf) 1 MeV ~ 10 10 K

17. He4 mass fraction n np p

18. There is no stable nuclei for A=5,8. Mass 7 nuclei are produced a little. cf) 0.1 MeV ~ 10 9 K

19. Time evolution of light elements

20. He4 D Li7 Li6 He3 Observational Light Element Abundances Peimbert,Lridiana, Peimbert(2007) Izotov,Thuan, Stasinska (2007) Melendez,Ramirez(2004) O’Meara et al. (2006) Asplund et al(2006) Geiss and Gloeckler (2003) Fukugita, Kawasaki (2006)

21. SBBN

23. Annihilation or decay during/after BBN epoch

24. Massive particle decaying/annihilating during/after BBN epoch produces high energy photons, hadrons, and neutrinos Destruction/production/dilution of light elements Severer constraints on the number density Sato and Kobayashi (1977), Lindley (1984,1985), Khlopov and Linde (1984) Ellis, Kim, Nanopoulos, (1984); Ellis, Nanopoulos, Sarkar (1985) Kawasaki and Sato (1987) Reno and Seckel (1988), Dimopoulos, Esmailzadeh, Hall, Starkman (1988) Kawasaki, Moroi (1994), Sigl et al (95), Holtmann et al (97) Jedamzik (2000), Kawasaki, Kohri, Moroi (2001), Kohri(2001), Cyburt, Ellis, Fields, Olive (2003) Kawasaki, Kohri, Moroi(04), Jedamzik (06)

25. Electromagnetic mode x D + p + n He3/D >~ O(1)

26. Hadronic mode

27. Extraordinary inter-conversion reactions between n and p Hadron induced exchange Even after freeze-out of n/p in SBBN More He4, D, Li7 … cf) （ I) Early stage of BBN （ I) Early stage of BBN (T > 0.1MeV) Reno and Seckel (1988) Kohri (2001)

28. (II) Late stage of BBN (T < 0.1MeV) Hadronic showers and “Hadro-dissociation” S. Dimopoulos et al. (1988) n (p) Kawasaki, Kohri, Moroi (2004)

29. Non-thermal Li, Be Production by energetic nucleons or photons Dimopoulos et al (1989) Energy loss ① T(He3) – He4 collision ② He4 – He4 collision Jedamzik (2000)

30. Residual annihilation of DM even at around BBN epoch To fit the PAMELA and ATIC2/Fermi positron and electron signals, At least it must emit charged leptons It might also emit hadrons Electromagnetic cascade shower is induced Hadronic cascade shower is induced

31. Hadron emission by residual annihilation in BBN epoch Hisano, Kawasaki, Kohri, Moroi, Nakayama (09)

32. Charged-lepton (e + e - ) emission by residual annihilation in BBN epoch Hisano, Kawasaki, Kohri, Moroi, Nakayama (09)

33. Residual annihilation and CMB Energy injection affects the recombination history of the Universe Changing the ionization fraction affects CMB anisotropy very sensitively Belicov and Hooper (09); Galli, Iocco, Bertone, Melchiorri (09); Huetsi, Hektor, Raidal (09) Cirelli, Iocco, Panci (09); Slatyer, Padmanabhan, Finkbeiner (09); Kanzaki, Kawasaki, Nakayama (09)

34. Constraint from CMB anisotropy Kanzaki, Kawasaki, Nakayama (09)

35. What is the origin of Boost Factor (BF~10 3 ) BF = obs / canonical Local enhancement of DM density in astrophys Sommerfeld effect Light particle exchange annihilation for m < αm DM (a kind of bound state formation, see also Hisano- Matsumoto-Nojiri (03) ) Non-perturbative effect Enhancement of cross section ~10 -23 cm 3 /s without breaking Unitarity and perturbation theory Arkani-Hamed et al (08)

36. Velocity-dependent annihilation cross section? Sommerfeld or Breit-Wigner enhancement The constraint from BBN and CMB is nontrivial See Zavala, Vogelsberger, White (09) for the constraint from μ- distortion of CMB

37. Hisano, Kawasaki, Kohri, Nakayama, arXiv: 0810.1892 [hep-ph] Gamma-ray signal from DM annihilation Gamma-ray flux Averaged over Profile Navarro-Frank-White (NFW): cusp structure Isothermal (iso): core structure

38. Kawasaki, Kohri, Nakayama (09) Gamma-ray signal from GC by DM annihilation

39. Results by Meade et al Meade, Papucci, Strumia, Volansky, arXiv:0905.0430

40. Gamma-ray obs by Fermi LAT Abdo et al, 0908.1171

41. Kawasaki, Kohri, Nakayama (09) Extragalactic diffuse Gamma-ray by DM annihilation

42. Neutrinos from galactic center expected by PAMELA/ATIC2 Detecting up-going muons in Kamioka Annihilation (upper panel) and decay (lower panel) Direct-neutrino emission modes with NFW are excluded Hisano, Kawasaki, Kohri, Nakayama (08) Hisano, Nakayama Yang(09)

43. Astrophysical origin? Supernova Remnants (SNRs) Pulsar GRB i.A local and old unknown SNR with n s <2 in radiative phase ii.Statistically-known SNRs with (re)acceleration of secondary positron Fujita, Kohri, Yamazaki, Ioka (09) Ahlers, Mertsch, Sarkar (09) See Kawanaka’s talk See Kunihito Ioka, arXiv:0812.4851[astro-ph]

44. An old SNR near the Earth Proton was accelerated at a local SNR (<200 pc) in a dense gas cloud (n~50/cc) 10 6 years ago p-p collision produces pions  electrons and positrons which propagated for 10 6 years The cloud had alrerady disappeared (see Loop I, Local Buble as its vestige) Antiproton was also produced Fujita, Kohri, Yamazaki, Ioka, arXiv:0903.5298

45. Source spectrum Spectrum Diffusion length

46. Fitted to Fermi by local SNR model Fujita, Kohri, Yamazaki, Ioka, arXiv:0903.5298

47. Fitted to Fermi by local SNR model Antiproton Fujita, Kohri, Yamazaki, Ioka, arXiv:0903.5298

48. Fitted to Fermi by pp collision model B/C is also increasing? Mertsch and Sarkar, arXiv:0905.3152v3arXiv:0905.3152v3 HEAO-3-C2 ATIC-2 CREAM

49. Summary Annihilation scenarios may have some problems to agree with BBN, CMB, and gamma-ray background It should be nontrivial to remove these discrepancies even if we adopt Sommerfeld or Breit-Wigner enhancement mechanism For astrophysical origin, so far we have not excluded a possible peculiar object such as a local and old SNR near the solar system.