TY - JOUR
T1 - PAMELA satellite data as a signal of non-thermal wino LSP dark matter
AU - Kane, Gordon
AU - Lu, Ran
AU - Watson, Scott
N1 - Funding Information:
We are grateful for discussions with Bobby Acharya, Nima Arkani-Hamed, Lars Bergström, Elliott Bloom, Mirko Boezio, Joachim Edsjö, Rouven Essig, Phill Grajek, Emiliano Macchiutti, Patrick Meade, Aldo Morselli, Igor Moskolenko, Michele Papucci, Cheng Peng, Piergiorgio Picozza, Tomer Volansky, Liantao Wang, Neal Weiner, and particularly Aaron Pierce who collaborated on parts of the research. S.W. would like to thank KITP, Perimeter Institute, and the University of Texas—Austin for hospitality, and University of Texas—Austin for support under National Science Foundation Grant no. PHY-0455649 .
PY - 2011/2/21
Y1 - 2011/2/21
N2 - We argue there is a very well motivated theoretical framework (which existed before data) consistent with the interpretation that dark matter annihilation is being observed by the PAMELA satellite detector. The dark matter is (mainly) the neutral W boson superpartner, the wino. Using the program GALPROP extensively we study the annihilation products and the backgrounds together. A wino mass approximately in the 180200 GeV range gives a good description of the PAMELA data, with antimatter and gammas from annihilating winos contributing or dominating the data below this energy range but not contributing above it. We explain why PAMELA data does not imply no antiproton signal was observed by PAMELA or earlier experiments, and explain why the antiproton analysis was misunderstood by earlier papers. Normalizing the wino density to the local relic density, no "boost factors" are needed. At higher energies we expect astrophysical mechanisms to contribute, and we simply parameterize them, and check that the combination can describe all the data. We emphasize several predictions for satellite data to test the wino interpretation, particularly the flattening or turndown of the positron and antiproton spectra above 100 GeV, and predictions for the Fermi detector. We emphasize that interpretations also depend very strongly on assumptions about the cosmological history of the universe, and that it is crucial to have independent criteria to define the background for any given process.
AB - We argue there is a very well motivated theoretical framework (which existed before data) consistent with the interpretation that dark matter annihilation is being observed by the PAMELA satellite detector. The dark matter is (mainly) the neutral W boson superpartner, the wino. Using the program GALPROP extensively we study the annihilation products and the backgrounds together. A wino mass approximately in the 180200 GeV range gives a good description of the PAMELA data, with antimatter and gammas from annihilating winos contributing or dominating the data below this energy range but not contributing above it. We explain why PAMELA data does not imply no antiproton signal was observed by PAMELA or earlier experiments, and explain why the antiproton analysis was misunderstood by earlier papers. Normalizing the wino density to the local relic density, no "boost factors" are needed. At higher energies we expect astrophysical mechanisms to contribute, and we simply parameterize them, and check that the combination can describe all the data. We emphasize several predictions for satellite data to test the wino interpretation, particularly the flattening or turndown of the positron and antiproton spectra above 100 GeV, and predictions for the Fermi detector. We emphasize that interpretations also depend very strongly on assumptions about the cosmological history of the universe, and that it is crucial to have independent criteria to define the background for any given process.
KW - Dark matter
KW - Indirect detection
KW - Super symmetry
UR - http://www.scopus.com/inward/record.url?scp=79951725004&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79951725004&partnerID=8YFLogxK
U2 - 10.1016/j.nima.2010.06.033
DO - 10.1016/j.nima.2010.06.033
M3 - Article
AN - SCOPUS:79951725004
SN - 0168-9002
VL - 630
SP - 82
EP - 86
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
IS - 1
ER -