MeV neutrino dark matter: Relic density, lepton flavour violation and electron recoil

Abstract

Right-handed neutrinos with MeV to GeV mass are very promising candidates for dark matter (DM). Not only can they solve the missing satellite puzzle, the cusp-core problem of inner DM density profiles, and the too-big-to fail problem, {\it i.e.} that the unobserved satellites are too big to not have visible stars, but they can also account for the Standard Model (SM) neutrino masses at one loop. We perform a comprehensive study of the right-handed neutrino parameter space and impose the correct observed relic density and SM neutrino mass differences and mixings. We find that the DM masses are in agreement with bounds from big-bang nucleosynthesis, but that these constraints induce sizeable DM couplings to the charged SM leptons. We then point out that previously overlooked limits from current and future lepton flavour violation experiments such as MEG and SINDRUM heavily constrain the allowed parameter space. Since the DM is leptophilic, we also investigate electron recoil as a possible direct detection signal, in particular in the XENON1T experiment. We find that despite the large coupling and low backgrounds, the energy thresholds are still too high and the predicted cross sections too low due to the heavy charged mediator, whose mass is constrained by LEP limits.

19 pages, 7 figures, version published in JHEP

References in corpus (22)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• The RAVE Survey: Constraining the Local Galactic Escape Speed
• The Local Dark Matter Density
• SENSEI: Direct-Detection Constraints on Sub-GeV Dark Matter from a Shallow Underground Run Using a Prototype Skipper-CCD
• US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report
• Research Proposal for an Experiment to Search for the Decay μ -> eee
• Full one-loop corrections to the relic density in the MSSM: A few examples
• BBN constraints on the annihilation of MeV-scale dark matter
• XENON1T Dark Matter Data Analysis: Signal & Background Models, and Statistical Inference
• Neutralino-stop co-annihilation into electroweak gauge and Higgs bosons at one loop
• SUSY-QCD Corrections to Dark Matter Annihilation in the Higgs Funnel
• Neutralino Annihilation into Massive Quarks with SUSY-QCD Corrections
• One-loop corrections to neutralino-stop coannihilation revisited
• SUSY-QCD effects on neutralino dark matter annihilation beyond scalar or gaugino mass unification
• SUSY-QCD corrections to stop annihilation into electroweak final states including Coulomb enhancement effects
• A Two Higgs Doublet Model for Dark Matter and Neutrino Masses
• One-loop corrections to gaugino (co-)annihilation into quarks in the MSSM
• SUSY-QCD corrections for the direct detection of neutralino dark matter and correlations with the relic density
• Squark-pair annihilation into quarks at next-to-leading order
• Relic density calculations beyond tree-level, exact calculations versus effective couplings: the ZZ final state
• Minimal dark matter models with radiative neutrino masses: From Lagrangians to observables

Cited by in corpus (2)

• Absorption of Fermionic Dark Matter by Nuclear Targets
• Cosmology and prospects for sub-MeV dark matter in electron recoil experiments