Axions and the strong CP problem
- Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)
Current upper bounds on the neutron electric dipole moment constrain the physically observable quantum chromodynamic (QCD) vacuum angle |{theta}|(less-or-similar sign)10{sup -11}. Since QCD explains a great deal of experimental data from the 100 MeV to the TeV scale, it is desirable to explain this smallness of |{theta}| in the QCD framework; this is the strong CP problem. There now exist two plausible solutions to this problem, one of which leads to the existence of a very light axion. The axion decay constant window, 10{sup 9}(less-or-similar sign)F{sub a}(less-or-similar sign)10{sup 12} GeV for an O(1) initial misalignment angle {theta}{sub 1}, has been obtained from astrophysical and cosmological data. For F{sub a}(greater-or-similar sign)10{sup 12} GeV with {theta}{sub 1}
- OSTI ID:
- 22038488
- Journal Information:
- Reviews of Modern Physics, Vol. 82, Issue 1; Other Information: (c) 2010 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6861
- Country of Publication:
- United States
- Language:
- English
Similar Records
Coupled Boltzmann computation of mixed axion neutralino dark matter in the SUSY DFSZ axion model
Axino dark matter in light of an anomalous X-ray line