Cosmological bounds on sub-GeV dark vector bosons from electromagnetic energy injection

• Published in: The journal of high energy physics Vol. 2020; no. 7; pp. 1 - 35
• Main Authors: Coffey, John, Forestell, Lindsay, Morrissey, David E., White, Graham
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2020; Springer Nature B.V; SpringerOpen
• Subjects: Big bang cosmology; Big Bang theory; Bosons; Classical and Quantum Gravitation; Cosmic microwave background; Decay; Elementary Particles; Frequency spectrum; High energy physics; Nuclear fusion; Nuclei (nuclear physics); Phenomenological Models; Photons; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; String Theory; Phenomenological Models
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP07(2020)179

A bstract New dark vector bosons that couple very feebly to regular matter can be created 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 alter the light element abundances or modify the power and frequency spectra of the CMB. In this work we study the constraints implied by these effects on a range of sub-GeV dark vectors including the kinetically mixed dark photon, and the B − L , L e − L μ , L e − L τ , and L μ − L τ dark U(1) bosons. We focus on the effects of electromagnetic energy injection, and we update previous investigations of dark photon and other dark vector decays by taking into account non-universality in the photon cascade spectrum relevant for BBN and the energy dependence of the ionization efficiency after recombination in our treatment of modifications to the CMB.