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Why PQ?

Peccei, R D
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Abstract

I discuss how the solution of the U(1){sub A} problem of QCD through the existence of the {theta}-vacuum gave rise to the strong CP problem. After examining various suggested solutions to this problem, I conclude that the only viable solution still is one that involves the existence of a spontaneously broken chiral symmetry: U(1){sub PQ}.

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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDSAXIONSBOSONSCHIRAL SYMMETRYCP INVARIANCEELEMENTARY PARTICLESFERMIONSFIELD THEORIESGOLDSTONE BOSONSINVARIANCE PRINCIPLESLIE GROUPSMASSMATHEMATICAL SOLUTIONSPOSTULATED PARTICLESQUANTUM CHROMODYNAMICSQUANTUM FIELD THEORYQUARKSREST MASSSYMMETRYSYMMETRY BREAKINGSYMMETRY GROUPSU GROUPSU-1 GROUPSVACUUM STATES

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Peccei, R D. 2010-08-30. Why PQ?. https://doi.org/10.1063/1.3489562

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