Improved cosmological bound on the thermal axion mass

Journal Article · Wed Aug 15 04:00:00 EDT 2007 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.76.041303· OSTI ID:21027546

Melchiorri, Alessandro; Mena, Olga ^[1]; Slosar, Anze ^[2]

---

1. INFN Sez. di Roma, Dipartimento di Fisica, Universita di Roma 'La Sapienza', P.le A. Moro, 5, I-00185 Rome (Italy)
2. Astrophysics, Denys Wilkinson Building, University of Oxford, Keble Road, OX3RH1, Oxford (United Kingdom)

Relic thermal axions could play the role of an extra hot dark matter component in cosmological structure formation theories. By combining the most recent observational data we improve previous cosmological bounds on the axion mass m{sub a} in the so-called hadronic axion window. We obtain a limit on the axion mass m{sub a}<0.42 eV at the 95% C.L. (m{sub a}<0.72 eV at the 99% C.L.). A novel aspect of the analysis presented here is the inclusion of massive neutrinos and how they may affect the bound on the axion mass. If neutrino masses belong to an inverted hierarchy scheme, for example, the above constraint is improved to m{sub a}<0.38 eV at the 95% C.L. (m{sub a}<0.67 eV at the 99% C.L.). Future data from experiments as CAST will provide a direct test of the cosmological bound.

• OSTI ID: 21027546
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 4 Vol. 76; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AXIONS
COSMOLOGY
EV RANGE
HADRONS
NEUTRINOS
NONLUMINOUS MATTER
REST MASS