Enhanced Rare Pion Decays from a Model of MeV Dark Matter
Abstract
A model has been proposed in which neutral scalar particles chi, of mass 1-10 MeV, annihilate through the exchange of a light vector boson U, of mass 10-100 MeV, to produce the 511 keV line observed emanating from the center of the galaxy. The chi interacts weakly with normal matter and is a viable dark matter candidate. If the U-boson couples to quarks as well as to electrons, it could enhance the branching ratio for the rare decay pi0 -> e+e-. A recent measurement by the KTeV Collaboration lies three standard deviations above a prediction by Dorokhov and Ivanov, and we relate this excess to the couplings of the U-boson. The values are consistent with other constraints and considerations. We make some comments on possible improvements in the data.
Cite
@article{arxiv.0712.0007,
title = {Enhanced Rare Pion Decays from a Model of MeV Dark Matter},
author = {Yonatan Kahn and Michael Schmitt and Tim Tait},
journal= {arXiv preprint arXiv:0712.0007},
year = {2012}
}
Comments
4 pages, 2 figures. Version published in PRD. V3: fixed a misplaced figure