Title

Is the PAMELA Positron Excess Winos?

Author(s)/Creator(s)

Scott Watson, Syracuse University
Phill Grajek, University of Michigan - Ann Arbor
Gordon L. Kane, University of Michigan - Ann Arbor
Daniel J. Phalen, University of Michigan - Ann Arbor
Aaron Pierce, University of Michigan - Ann Arbor

Document Type

Article

Date

12-24-2008

Language

English

Disciplines

Physics

Description/Abstract

Recently the PAMELA satellite-based experiment reported an excess of galactic positrons that could be a signal of annihilating dark matter. The PAMELA data may admit an interpretation as a signal from a wino-like LSP of mass about 200 GeV, normalized to the local relic density, and annihilating mainly into W-bosons. This possibility requires the current conventional estimate for the energy loss rate of positrons be too large by roughly a factor of five. Data from anti-protons and gamma rays also provide tension with this interpretation, but there are significant astrophysical uncertainties associated with their propagation. It is not unreasonable to take this well-motivated candidate seriously, at present, in part because it can be tested in several ways soon. The forthcoming PAMELA data on higher energy positrons and the FGST (formerly GLAST) data, should provide important clues as to whether this scenario is correct. If correct, the wino interpretation implies a cosmological history in which the dark matter does not originate in thermal equilibrium.

Additional Information

7 pages, 4 figues More informaton at http://arxiv.org/abs/0812.4555

Recommended Citation

Watson, Scott; Grajek, Phill; Kane, Gordon L.; Phalen, Daniel J.; and Pierce, Aaron, "Is the PAMELA Positron Excess Winos?" (2008). Physics - All Scholarship. 404.
https://surface.syr.edu/phy/404

Source

Harvested from Arxiv.org

Creative Commons License

This work is licensed under a Creative Commons Attribution 3.0 License.