6533b7d7fe1ef96bd1269023

RESEARCH PRODUCT

Cosmological constraints on heavy sterile neutrinos

Leonardo Mastrototaro

subject

HistoryHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)Computer Science::Information RetrievalHigh Energy Physics::PhenomenologyFOS: Physical sciencesHigh Energy Physics::ExperimentAstrophysics::Cosmology and Extragalactic AstrophysicsComputer Science ApplicationsEducation

description

We consider heavy sterile neutrinos $\nu_s$, with mass in the range 10 MeV $\lesssim m_s \lesssim m_{\pi} \sim 135$ MeV, thermally produced in the early universe and freezing out after the QCD phase transition. The existence of these neutrinos may alter the value of the effective number of neutrino species $N_{\rm eff}$, measured by the cosmic microwave background (CMB), and the ${}^4$He production during the BBN. We provide a detailed account of the solution of the relevant Boltzmann equations and we identify the parameter space constrained by current Planck satellite data and forecast the parameter space probed by future Stage-4 ground-based CMB (CMB-S4) observations.

10.1088/1742-6596/2156/1/012009http://arxiv.org/abs/2202.11390