A stellar evolution bound on radiative particle decays and the cosmic microwave background distortion

Abstract

view Abstract Citations (32) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Stellar Evolution Bound on Radiative Particle Decays and the Cosmic Microwave Background Distortion Raffelt, Georg ; Dearborn, David ; Silk, Joseph Abstract It has been suggested that a recently measured distortion of the cosmic microwave background (CMB) spectrum may be interpreted as a signature for primeval particle decays, χ or approaches {chih}'γ. However, the plasma decay process γ_pl_ or approaches χ^barchi', or χχ^bar^' would then also be possible, leading to anomalous energy losses for stars. We have implemented this loss rate in a stellar evolution code and discuss the resulting changes in the evolutionary pattern of low-mass stars. A comparison with observational data indicates that the range of particle parameters 10^5^ <~ (τ_rad_/yr)(m/eV)^3^ < 1.2 x 10^14^ is excluded where τ_rad_ is the χ radiative lifetime. This result applies to the generic case of neutral spin 1/2 particles ("neutrinos"), but it can be generalized to a broad class of cases. For χ approaches γγ the bound is more restrictive, excluding 10^5^ <~ (τ_rad_/yr)(m/eV)^3^ < 4.2 x 10^17^. These results rule out any simple interpretation of the CMB distortion in terms of late particle decays. Our result also leads to an upper bound of 1 x 10^-11^ μ_B_ (Bohr magneton μ_B_) on the magnetic dipole moment of any light neutrino species, ruling out a recently proposed explanation for the possible time variation of the measured solar neutrino flux. Publication: The Astrophysical Journal Pub Date: January 1989 DOI: 10.1086/166993 Bibcode: 1989ApJ...336...61R Keywords: Background Radiation; Cosmic Rays; Elementary Particles; Microwaves; Radioactive Decay; Stellar Evolution; Open Clusters; Plasma Decay; Solar Neutrinos; Stellar Mass; Astrophysics; CLUSTERS: OPEN; COSMIC BACKGROUND RADIATION; EARLY UNIVERSE; ELEMENTARY PARTICLES; NEUTRINOS; STARS: HORIZONTAL-BRANCH full text sources ADS | data products SIMBAD (1)