D'Elia M, Mariti M, Negro F. Susceptibility of the QCD vacuum to CP-odd electromagnetic background fields.
PHYSICAL REVIEW LETTERS 2013;
110:082002. [PMID:
23473133 DOI:
10.1103/physrevlett.110.082002]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Indexed: 06/01/2023]
Abstract
We investigate two flavor quantum chromodynamics (QCD) in the presence of CP-odd electromagnetic background fields and determine, by means of lattice QCD simulations, the induced effective θ term to first order in E[over →] · B[over →]. We employ a rooted staggered discretization and study lattice spacings down to 0.1 fm and Goldstone pion masses around 480 MeV. In order to deal with a positive measure, we consider purely imaginary electric fields and real magnetic fields, and then exploit the analytic continuation. Our results are relevant to a description of the effective pseudoscalar quantum electrodynamics-QCD interactions.
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