Cosmic microwave background constraints on secret interactions among sterile neutrinos
- Istituto Nazionale di Fisica Nucleare (INFN), Ferrara (Italy); Univ. di Ferrara (Italy)
- Istituto Nazionale di Fisica Nucleare (INFN), Ferrara (Italy)
- Istituto Nazionale di Fisica Nucleare (INFN), Napoli (Italy)
- Istituto Nazionale di Fisica Nucleare (INFN), Bari (Italy); Dipartimento Interateneo di Fisica, Bari (Italy)
- Johannes Gutenberg Univ., Mainz (Germany)
Secret contact interactions among eV sterile neutrinos, mediated by a massive gauge boson X (with MX ≪ MW), and characterized by a gauge coupling gX, have been proposed as a mean to reconcile cosmological observations and short-baseline laboratory anomalies. We constrain this scenario using the latest Planck data on Cosmic Microwave Background anisotropies, and measurements of baryon acoustic oscillations (BAO). We consistently include the effect of secret interactions on cosmological perturbations, namely the increased density and pressure fluctuations in the neutrino fluid, and still find a severe tension between the secret interaction framework and cosmology. In fact, taking into account neutrino scattering via secret interactions, we derive our own mass bound on sterile neutrinos and find (at 95 % CL) ms < 0.82 eV or ms < 0.29 eV from Planck alone or in combination with BAO, respectively. These limits confirm the discrepancy with the laboratory anomalies. Moreover, we constrain, in the limit of contact interaction, the effective strength GX to be < 2.8 (2.0) × 1010 GF from Planck (Planck+BAO). This result, together with the mass bound, strongly disfavours the region with MX ~ 0.1 MeV and relatively large coupling gX~ 10-1, previously indicated as a possible solution to the small scale dark matter problem.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1543934
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2017, Issue 07; ISSN 1475-7516
- Publisher:
- Institute of Physics (IOP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Probing secret interactions of eV-scale sterile neutrinos with the diffuse supernova neutrino background
Sterile neutrinos with secret interactions — lasting friendship with cosmology