Dark photon decay beyond the Euler-Heisenberg limit
Abstract
We calculate the exact width for a dark photon decaying to three photons at one-loop order for dark photon masses m' below the e+e- production threshold of 2 me. We find substantial deviations from previous results derived from the lowest order Euler-Heisenberg effective Lagrangian in the range me≲m'≤2 me, 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 850 KeV ≲m'≤2 me , 10-5≲ɛ ≲10-4 that is only constrained by possibly model-dependent bounds on the number of light degrees of freedom in the early Universe.
- Publication:
-
Physical Review D
- Pub Date:
- April 2018
- DOI:
- 10.1103/PhysRevD.97.073005
- arXiv:
- arXiv:1705.00619
- Bibcode:
- 2018PhRvD..97g3005M
- Keywords:
-
- High Energy Physics - Phenomenology;
- Astrophysics - High Energy Astrophysical Phenomena;
- High Energy Physics - Theory
- E-Print:
- 6 pages