APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Graham White (TRIUMF)
Title: BBN and CMB bounds on hidden sector vectors
Date: Mon, Apr 06, 2020, 11:00 - 12:00
Place: Zoom Seminar
Related File: 2532.pdf
Abstract: New dark vector bosons that couple very feebly to regular matter can be produced
in the early universe and decay after the onset of Big Bang Nucleosynthesis (BBN)
or the formation of the cosmic microwave background (CMB) at recombination. The
energy injected by such decays can modify the light element abundances or modify
the power and frequency spectra of the CMB. In this work we study the constraints
implied by these considerations on a range of sub-GeV dark vectors including the
kinetically mixed dark photon, as well as gauge B-L and lepton families. We focus on the
effects of electromagnetic energy injection, and we update
previous investigations of the dark photon by taking into account non-universality
in the photon cascade spectrum relevant for BBN and the energy dependence of the
ionization eciency after recombination in our treatment of modications to the CMB.