1. Implications of new physics from cosmic e+- excesses
Bi Xiao-Jun （毕效军）
IHEP, CAS （中科院高能所）

2. PAMELA results of antiparticles in cosmic rays
Positron fraction
Antiproton fraction
PAMELA released data on the positron/electron ratio up to about 100 GeV, which show clear excess above ~10 GeV. The low energy data is affected by the solar environment and we do not need care it too much.
Nature 458, 607 (2009)
Phys.Rev.Lett.102:051101,2009
368 citations after submitted on 28th Oct. 2008, 1paper per day

3. The total electron spectrum
ATIC bump
Fermi excess
Chang et al. Nature456,
Phys.Rev.Lett.102:181101,2009

4. Possible explanations
The background calculation is problematic
The local astrophysical sources (pulsars, SNRs …)
High energy cosmic rays interaction with ambient photons at the early stage of acceleration of CRs
Propagation effects, no excess, …
DM annihilation or decays …

5. Primary positron/electrons from dark matter – implication from new data
DM annihilation/decay produce leptons mainly in order not to produce too much antiprotons.
Very hard electron spectrum -> dark matter annihilates/decay into leptons.
Very large annihilation cross section, much larger (~1000) than the requirement by relic density. ( 1) nonthermal production, 2) Sommerfeld enhancement, 3) Breit-Wigner enhancement, 4) dark matter decay.)

6. positron ratio from DM annihilation
Yin, et al. arXiv:

7. Upper bounds on the WW and quark branching ratios for DM annihilation
Bi, Li, Zhang

8. Constraints on some DM models (~1TeV)
Neutralino, mainly into gauge bosons; excluded
In UED KK mode of U(1)Y gauge boson, ~30% into quarks (universal KK mass); marginally allowed
U(1)’B-L, ~40% into quarks, slightly disfavored
Leptophilic models U(1)’e-mu(tau), best fit data

9. MCMC fit to the ATIC or Fermi and PAMELA data
Liu, Yuan, Bi, Li, Zhang,
Astro-ph/
Background fixed
Background not fixed
To determine nature of DM has to resort to colliders.

10. Leptonic DM and neutrinos
DM models related with neutrino masses (Bi et al ; Cao et al  … )

11. Dark matter models to produce leptons
Kinematically suppression
Mass of φis about 1GeV, is
Kinematically suppressed to antiprotons;
At the same time attractive interaction can enhance the annihilaition rate, Sommerfeld enhancement. (Arkani-Hamed et al   )
DM +DM -> φφ, φ-> μ+μ−; Φ can be generated at colliders by mixing with SM Higgs or gauge bosons;
Signals of such scenarios at colliders are lepton jets with invariant mass ~ 1GeV
A light pseudoscalar model with DM +DM -> sa, a -> μ+μ−, s -> aa may have different collider signals (Nomura & Thaler, arXiv: )

12. Breit-Wigner enhancement

13. Dynamically suppression, φ carries U(1)’e-μ(τ) and U(1)’B-3e,μ(τ) (Bi, He, Yuan, arXiv: , Bi, He, Ma, Zhang, arXiv:   )
Hard to have any collider tests
Neutrinos from the GC can be detected at 8.5(2.6) σfor 4 year data taking at IceCube.
U(1)’ models

14. Emission from the GC Constraint on the central density of DM Tension
Bi et al.,
Constraint on the central density of DM
Tension
Exist for the
annihilating
DM scenario
Liu et al.,

15. Constraints on the minimal subhalos by observations of clusters
A. Pinzke et al.,
Standard CDM predicts the minimal subhalos
Observation constrains
Fermi limit to
DM is warm

16. Constraints from extragalactic diffuse gamma rays
S. Profumo et al.,

17. Summary Anomalies observed in cosmic electrons and positrons;
The cosmic ray observations may discover new physics at the DM sector; however hard to give precise determination of its properties because of large astrophysical uncertainties. Colliders are necessary.
New data will come soon: PAMELA finally detect positron to 270GeV; antiproton to 190 GeV (published <100GeV); total e+e- to 2 TeV (not released); AMS02 launch at 2010; Re-flight of ATIC for electrons (AREL) was proposed to NASA Mar. 2009; Fermi results of diffuse gamma rays