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DTSTART:20170326T010000
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DTSTART:20171029T010000
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BEGIN:VEVENT
DTSTART;TZID=Europe/Rome:20170215T120000
DTEND;TZID=Europe/Rome:20170215T130000
DTSTAMP:20260910T140143
CREATED:20171026T122534Z
LAST-MODIFIED:20171026T122534Z
UID:6907-1487160000-1487163600@w3.lnf.infn.it
SUMMARY:The dirty side of the axion
DESCRIPTION:Since the early 90’s it was understood that in order for the Peccei Quinn (PQ) mechanism to work the global U(1)_PQ had to be realized to an extremely high level of accuracy. In fact\, even a tiny explicit breaking of the global PQ symmetry (e.g. via Planck-induced effective operators) would sizably contribute to the axion vacuum energy density and prevent the θ angle to relax to a value below the experimental upper bound |θ| < 10^-10. In this contribution\, I will reproduce the standard argument and review possible mechanisms in order to protect the axion.
URL:/event/the-dirty-side-of-the-axion/
LOCATION:Aula Direzione
CATEGORIES:Seminari teorici
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