skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Cosmic microwave background constraints on secret interactions among sterile neutrinos

Abstract

Secret contact interactions among eV sterile neutrinos, mediated by a massive gauge boson X (with M {sub X} || M {sub W} ), and characterized by a gauge coupling g {sub X} , 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) m {sub s} < 0.82 eV or m {sub s} < 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 G {sub X} to be < 2.8 (2.0) × 10{sup 10} G {sub F} from Planck (Planck+BAO). This result, together with the mass bound, strongly disfavours the region withmore » M {sub X} ∼ 0.1 MeV and relatively large coupling g {sub X} {sub ∼} 10{sup −1}, previously indicated as a possible solution to the small scale dark matter problem.« less

Authors:
;  [1];  [2];  [3];  [4];  [5]
  1. Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Via Giuseppe Saragat 1, I-44122 Ferrara (Italy)
  2. Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Via Giuseppe Saragat 1, I-44122 Ferrara (Italy)
  3. Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Complesso Univ. Monte S.Angelo, I-80126 Napoli (Italy)
  4. Dipartimento Interateneo di Fisica 'Michelangelo Merlin,' Via Amendola 173, 70126 Bari (Italy)
  5. PRISMA Cluster of Excellence and Mainz Institute for Theoretical Physics, JohannesGutenberg-Universität Mainz, 55099 Mainz (Germany)
Publication Date:
OSTI Identifier:
22676089
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 07; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANISOTROPY; BARYONS; BOSONS; COSMOLOGY; COUPLING; DENSITY; DISTURBANCES; FLUCTUATIONS; FLUIDS; INTERACTIONS; MASS; MATHEMATICAL SOLUTIONS; MEV RANGE; NONLUMINOUS MATTER; OSCILLATIONS; PERTURBATION THEORY; RELICT RADIATION; SCATTERING; STERILE NEUTRINOS

Citation Formats

Forastieri, Francesco, Natoli, Paolo, Lattanzi, Massimiliano, Mangano, Gianpiero, Mirizzi, Alessandro, and Saviano, Ninetta, E-mail: francesco.forastieri@unife.it, E-mail: lattanzi@fe.infn.it, E-mail: mangano@na.infn.it, E-mail: alessandro.mirizzi@ba.infn.it, E-mail: natoli@fe.infn.it, E-mail: nsaviano@uni-mainz.de. Cosmic microwave background constraints on secret interactions among sterile neutrinos. United States: N. p., 2017. Web. doi:10.1088/1475-7516/2017/07/038.
Forastieri, Francesco, Natoli, Paolo, Lattanzi, Massimiliano, Mangano, Gianpiero, Mirizzi, Alessandro, & Saviano, Ninetta, E-mail: francesco.forastieri@unife.it, E-mail: lattanzi@fe.infn.it, E-mail: mangano@na.infn.it, E-mail: alessandro.mirizzi@ba.infn.it, E-mail: natoli@fe.infn.it, E-mail: nsaviano@uni-mainz.de. Cosmic microwave background constraints on secret interactions among sterile neutrinos. United States. doi:10.1088/1475-7516/2017/07/038.
Forastieri, Francesco, Natoli, Paolo, Lattanzi, Massimiliano, Mangano, Gianpiero, Mirizzi, Alessandro, and Saviano, Ninetta, E-mail: francesco.forastieri@unife.it, E-mail: lattanzi@fe.infn.it, E-mail: mangano@na.infn.it, E-mail: alessandro.mirizzi@ba.infn.it, E-mail: natoli@fe.infn.it, E-mail: nsaviano@uni-mainz.de. Sat . "Cosmic microwave background constraints on secret interactions among sterile neutrinos". United States. doi:10.1088/1475-7516/2017/07/038.
@article{osti_22676089,
title = {Cosmic microwave background constraints on secret interactions among sterile neutrinos},
author = {Forastieri, Francesco and Natoli, Paolo and Lattanzi, Massimiliano and Mangano, Gianpiero and Mirizzi, Alessandro and Saviano, Ninetta, E-mail: francesco.forastieri@unife.it, E-mail: lattanzi@fe.infn.it, E-mail: mangano@na.infn.it, E-mail: alessandro.mirizzi@ba.infn.it, E-mail: natoli@fe.infn.it, E-mail: nsaviano@uni-mainz.de},
abstractNote = {Secret contact interactions among eV sterile neutrinos, mediated by a massive gauge boson X (with M {sub X} || M {sub W} ), and characterized by a gauge coupling g {sub X} , 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) m {sub s} < 0.82 eV or m {sub s} < 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 G {sub X} to be < 2.8 (2.0) × 10{sup 10} G {sub F} from Planck (Planck+BAO). This result, together with the mass bound, strongly disfavours the region with M {sub X} ∼ 0.1 MeV and relatively large coupling g {sub X} {sub ∼} 10{sup −1}, previously indicated as a possible solution to the small scale dark matter problem.},
doi = {10.1088/1475-7516/2017/07/038},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 07,
volume = 2017,
place = {United States},
year = {Sat Jul 01 00:00:00 EDT 2017},
month = {Sat Jul 01 00:00:00 EDT 2017}
}
  • Sterile neutrinos with mass ≃1 eV and order 10% mixing with active neutrinos have been proposed as a solution to anomalies in neutrino oscillation data, but are tightly constrained by cosmological limits. It was recently shown that these constraints are avoided if sterile neutrinos couple to a new MeV-scale gauge boson A{sup ′}. However, even this scenario is restricted by structure formation constraints when A{sup ′}-mediated collisional processes lead to efficient active-to-sterile neutrino conversion after neutrinos have decoupled. In view of this, we reevaluate in this paper the viability of sterile neutrinos with such “secret” interactions. We carefully dissect theirmore » evolution in the early Universe, including the various production channels and the expected modifications to large scale structure formation. We argue that there are two regions in parameter space — one at very small A{sup ′} coupling, one at relatively large A{sup ′} coupling — where all constraints from big bang nucleosynthesis (BBN), cosmic microwave background (CMB), and large scale structure (LSS) data are satisfied. Interestingly, the large A{sup ′} coupling region is precisely the region that was previously shown to have potentially important consequences for the small scale structure of dark matter halos if the A{sup ′} boson couples also to the dark matter in the Universe.« less
  • Sterile neutrinos with mass ≅ 1 eV and order 10% mixing with active neutrinos have been proposed as a solution to anomalies in neutrino oscillation data, but are tightly constrained by cosmological limits. It was recently shown that these constraints are avoided if sterile neutrinos couple to a new MeV-scale gauge boson A'. However, even this scenario is restricted by structure formation constraints when A'-mediated collisional processes lead to efficient active-to-sterile neutrino conversion after neutrinos have decoupled. In view of this, we reevaluate in this paper the viability of sterile neutrinos with such ''secret'' interactions. We carefully dissect their evolution inmore » the early Universe, including the various production channels and the expected modifications to large scale structure formation. We argue that there are two regions in parameter space—one at very small A' coupling, one at relatively large A' coupling—where all constraints from big bang nucleosynthesis (BBN), cosmic microwave background (CMB), and large scale structure (LSS) data are satisfied. Interestingly, the large A' coupling region is precisely the region that was previously shown to have potentially important consequences for the small scale structure of dark matter halos if the A' boson couples also to the dark matter in the Universe.« less
  • We update a previous investigation of cosmological effects of a nonstandard interaction between neutrinos and dark matter. Parametrizing the elastic-scattering cross section between the two species as a function of the temperature of the Universe, the resulting neutrino-dark matter fluid has a nonzero pressure, which determines diffusion-damped oscillations in the matter power spectrum similar to the acoustic oscillations generated by the photon-baryon fluid. Using cosmic microwave background data in combination with large scale structure experiment results, we then put constraints on the fraction of the interacting dark matter component as well as on the corresponding opacity.
  • Several cosmological measurements have attained significant levels of maturity and accuracy over the past decade. Continuing this trend, future observations promise measurements of the cosmic mass distribution at an accuracy level of 1% out to spatial scales with k{approx}10h Mpc{sup -1} and even smaller, entering highly nonlinear regimes of gravitational instability. In order to interpret these observations and extract useful cosmological information from them, such as the equation of state of dark energy, very costly high precision, multiphysics simulations must be performed. We have recently implemented a new statistical framework with the aim of obtaining accurate parameter constraints from combiningmore » observations with a limited number of simulations. The key idea is the replacement of the full simulator by a fast emulator with controlled error bounds. In this paper, we provide a detailed description of the methodology and extend the framework to include joint analysis of cosmic microwave background and large-scale structure measurements. Our framework is especially well suited for upcoming large-scale structure probes of dark energy such as baryon acoustic oscillations and, especially, weak lensing, where percent level accuracy on nonlinear scales is needed.« less
  • It has been recently shown that the presence of a vector field over cosmological scales could explain the observed accelerated expansion of the Universe without introducing either new scales or unnatural initial conditions in the early Universe, thus avoiding the coincidence problem. Here, we present a detailed analysis of the constraints imposed by supernova type Ia (SNIa), cosmic microwave background (CMB), and baryon acoustic oscillation (BAO) data on the vector dark energy model with general spatial curvature. We find that contrary to standard cosmology, CMB data exclude a flat universe for this model and, in fact, predict a closed geometrymore » for the spatial sections. We see that CMB and SNIa Gold data are perfectly compatible at the 1-sigma level, however the SNIa Union data set exhibits a 3-sigma tension with CMB. The same level of tension is also found between SNIa and BAO measurements.« less