Electroweak bremsstrahlung in dark matter annihilation
Nicole F Bell, James B Dent, Thomas D Jacques, Thomas J Weiler
PHYSICAL REVIEW D | AMER PHYSICAL SOC | Published : 2008
A conservative upper bound on the total dark matter annihilation rate can be obtained by constraining the appearance rate of the annihilation products which are hardest to detect. The production of neutrinos, via the process χχ→ν̄ν, has thus been used to set a strong general bound on the dark matter annihilation rate. However, standard model radiative corrections to this process will inevitably produce photons which may be easier to detect. We present an explicit calculation of the branching ratios for the electroweak bremsstrahlung processes χχ→ν̄νZ and χχ→ν̄eW. These modes inevitably lead to electromagnetic showers and further constraints on the dark matter annihilation cross section. In a..View full abstract
Awarded by U. S. DOE
We thank John Beacom, Michael Kachelriess, Pasquale Serpico, Michael Ramsey-Musolf and Ray Volkas for helpful discussions. N. F. B. was supported by the University of Melbourne Early Career Researcher and Melbourne Research Grant Schemes, T. D. J. was supported by the Commonwealth of Australia, T. J. W. and J. B. D. were supported in part by U. S. DOE Grant No. DE-FG05-85ER40226, and T. J. W. benefited from the gracious hospitality of the University of Melbourne.