Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-10-30
JCAP 0912:007,2009
Astronomy and Astrophysics
Astrophysics
4 pages, 2 figures; v3 separated pions plot, references added
Scientific paper
10.1088/1475-7516/2009/12/007
Recently published results from the PAMELA experiment have shown conclusive evidence for an excess of positrons at high (~ 10 - 100 GeV) energies, confirming earlier indications from HEAT and AMS-01. Such a signal is generally expected from dark matter annihilations. However, the hard positron spectrum and large amplitude are difficult to achieve in most conventional WIMP models. The absence of any associated excess in anti-protons is highly constraining on any model with hadronic annihilation modes. We revisit an earlier proposal, whereby the dark matter annihilates into a new light (<~GeV) boson phi, which is kinematically constrained to go to hard leptonic states, without anti-protons or pi0's. We find this provides a very good fit to the data. The light boson naturally provides a mechanism by which large cross sections can be achieved through the Sommerfeld enhancement, as was recently proposed. Depending on the mass of the WIMP, the rise may continue above 300 GeV, the extent of PAMELA's ability to discriminate electrons and positrons.
Cholis Ilias
Finkbeiner Douglas Paul
Goodenough Lisa
Weiner Neal
No associations
LandOfFree
The PAMELA Positron Excess from Annihilations into a Light Boson does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The PAMELA Positron Excess from Annihilations into a Light Boson, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The PAMELA Positron Excess from Annihilations into a Light Boson will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-277695