Abstract
We calculate the exact width for a dark photon decaying to three photons at one-loop order for dark photon masses below the production threshold of . We find substantial deviations from previous results derived from the lowest order Euler-Heisenberg effective Lagrangian in the range , where higher order terms in the derivative expansion are non-negligible. This mass range is precisely where the three photon decay takes place on cosmologically relevant timescales. Our improved analysis reveals a window for dark photons in the range , that is only constrained by possibly model-dependent bounds on the number of light degrees of freedom in the early Universe.
- Received 24 May 2017
DOI:https://doi.org/10.1103/PhysRevD.97.073005
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Published by the American Physical Society