Enhanced rare pion decays from a model of MeV dark matter
Physical Review D—Particles, Fields, Gravitation, and Cosmology, 2008•APS
A model has been proposed in which neutral scalar particles χ, 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 χ 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 π 0→ e+ e-. A
recent measurement by the KTeV Collaboration lies 3 standard deviations above a …
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 χ 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 π 0→ e+ e-. A
recent measurement by the KTeV Collaboration lies 3 standard deviations above a …
A model has been proposed in which neutral scalar particles , of mass 1–10 MeV, annihilate through the exchange of a light vector boson , of mass 10–100 MeV, to produce the 511 keV line observed emanating from the center of the Galaxy. The interacts weakly with normal matter and is a viable dark matter candidate. If the boson couples to quarks as well as to electrons, it could enhance the branching ratio for the rare decay . A recent measurement by the KTeV Collaboration lies 3 standard deviations above a prediction by Dorokhov and Ivanov, and we relate this excess to the couplings of the boson. The values are consistent with other constraints and considerations. We make some comments on possible improvements in the data.
American Physical Society