Abstract
We point out that the long-standing strong CP problem may be resolved by an anthropic argument. The key ideas are: (i) to allow explicit breaking(s) of the Peccei-Quinn symmetry which reduces the strong CP problem to the cosmological constant problem, and (ii) to conjecture that the probability distribution of the vacuum energy has a mild pressure towards higher values. The cosmological problems of the (s)axion with a large Peccei-Quinn scale are absent in our mechanism, since the axion acquires a large mass from the explicit breaking.
Original language | English |
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Pages (from-to) | 711-725 |
Number of pages | 15 |
Journal | Progress of Theoretical Physics |
Volume | 121 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2009 Apr |