Cosmological Bound on the QCD Axion Mass, Redux

Abstract

We revisit the joint constraints in the mixed hot dark matter scenario in which both thermally produced QCD axions and relic neutrinos are present. Upon recomputing the cosmological axion abundance via recent advances in the literature, we improve the state-of-the-art analyses and provide updated bounds on axion and neutrino masses. By avoiding approximate methods, such as the instantaneous decoupling approximation, and limitations due to the limited validity of the perturbative approach in QCD that forced to artificially divide the constraints from the axion-pion and the axion-gluon production channels, we find robust and self-consistent limits. We investigate the two most popular axion frameworks: KSVZ and DFSZ. From Big Bang Nucleosynthesis (BBN) light element abundances data we find for the KSVZ axion $\Delta N_{\mathrm{eff}}<0.31$ and an axion mass bound $m_a<0.53$ eV (i.e., a bound on the axion decay constant $f_a>1.07\times 10^7$ GeV) both at $95\%$ CL. These BBN bounds are improved to $\Delta N_{\mathrm{eff}}<0.14$ and $m_a<0.16$ eV ($f_a>3.56\times 10^7$ GeV) if a prior on the baryon energy density from Cosmic Microwave Background (CMB) data is assumed. When instead considering cosmological observations from the CMB temperature, polarization and lensing from the Planck satellite combined with large scale structure data we find $\Delta N_{\mathrm{eff}}<0.23$, $m_a<0.28$ eV ($f_a>2.02\times 10^7$ GeV) and $\sum m_{\nu }<0.16$ eV at $95\%$ CL. This corresponds approximately to a factor of $5$ improvement in the axion mass bound with respect to the existing limits. Very similar results are obtained for the DFSZ axion. We also forecast upcoming observations from future CMB and galaxy surveys, showing that they could reach percent level errors for $m_a\sim 1$ eV.

22 pages, 9 figures, 5 tables. V2: updated to match the JCAP published version

References in corpus (25)

• The Clustering of the SDSS DR7 Main Galaxy Sample I: A 4 per cent Distance Measure at z=0.15
• An Improved Experimental Limit on the Electric Dipole Moment of the Neutron
• Measurement of the permanent electric dipole moment of the neutron
• The effects of He I 10830 on helium abundance determinations
• Probing cosmological parameters with the CMB: Forecasts from full Monte Carlo simulations
• Thermal axion production in the primordial quark-gluon plasma
• Relic Neutrinos, thermal axions and cosmology in early 2014
• A new tension in the cosmological model from primordial deuterium?
• Primordial Deuterium after LUNA: concordances and error budget
• The Impact of New d(p,γ)He3 Rates on Big Bang Nucleosynthesis
• An improved cosmological bound on the thermal axion mass
• PArthENoPE Revolutions
• Thermal axion production at low temperatures: a smooth treatment of the QCD phase transition
• Thermal QCD Axions across Thresholds
• Cosmological constraints on neutrino plus axion hot dark matter
• Novel cosmological bounds on thermally-produced axion-like particles
• The DFSZ axion in the CMB
• Production of Thermal Axions across the ElectroWeak Phase Transition
• Future cosmological sensitivity for hot dark matter axions
• Cosmological Implications of Axion-Matter Couplings
• Flavor Violating Axions in the Early Universe
• Multiverse Dark Matter: SUSY or Axions
• Thermal axions with multi-eV masses are possible in low-reheating scenarios
• Cosmological forecasts on thermal axions, relic neutrinos and light elements
• Robustness of cosmological axion mass limits

Cited by in corpus (39)

• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• Robust Preference for Dynamical Dark Energy in DESI BAO and SN Measurements
• Astrophysical Axion Bounds: The 2024 Edition
• Neutrino cosmology after DESI: tightest mass upper limits, preference for the normal ordering, and tension with terrestrial observations
• Getting the most on supernova axions
• Massive neutrinos and cosmic composition
• Revealing the effects of curvature on the cosmological models
• Health checkup test of the standard cosmological model in view of recent Cosmic Microwave Background Anisotropies experiments
• Novel cosmological bounds on thermally-produced axion-like particles
• Inflation, the Hubble Tension and Early Dark Energy: an alternative overview
• Axion Astrophysics
• Quantifying the global "CMB tension" between the Atacama Cosmology Telescope and the Planck satellite in extended models of cosmology
• Towards a reliable calculation of relic radiation from primordial gravitational waves
• Smoothing the $H_0$ tension with a dynamical dark energy model
• Ruling out light axions: the writing is on the wall
• Axion minivoids and implications for direct detection
• Axion-pion thermalization rate in unitarized NLO chiral perturbation theory
• Axion emission from supernovae: a cheatsheet
• Planck-PR4 anisotropy spectra show (better) consistency with General Relativity
• A novel model-marginalized cosmological bound on the QCD axion mass
• Neutrino mass tension or suppressed growth rate of matter perturbations?
• Probing HNL-ALP couplings at colliders
• The QCD Axion: Some Like It Hot
• Detecting Fundamental Vector Fields with LISA
• Back to the phase space: thermal axion dark radiation via couplings to standard model fermions
• Revisiting signatures of thermal axions in nonstandard cosmologies
• Lensing impact on cosmic relics and tensions
• Dark Radiation from the Primordial Thermal Bath in Momentum Space
• Joint Constraints on the Hubble Constant, Spatial Curvature, and Sound Horizon from the Late-time Universe with Cosmography
• Solar chameleons: Novel channels
• Precise predictions for the QCD axion contribution to dark radiation with full phase-space evolution
• Running effects on QCD axion phenomenology
• QCD topology and axion properties in an isotropic hot and dense medium
• New Source for QCD Axion Dark Matter Production: Curvature Induced
• Ultimate light-shining-through-a-wall experiments to establish QCD axions as the dominant form of dark matter
• Visible GeV ALP from TeV Vector-like Leptons
• Improved cosmological constraints on axion-lepton interactions
• Axions at the meV Crossroads: Theory, Cosmology, Astrophysics, and Experiments
• Beyond thermal approximations: Precise cosmological bounds on Axion-Like Particles