TY - JOUR
T1 - Bounds on rare decays of η and η′ mesons from the neutron EDM
AU - Zhevlakov, Alexey S.
AU - Gorchtein, Mikhail
AU - Blin, Astrid N.Hiller
AU - Gutsche, Thomas
AU - Lyubovitskij, Valery E.
PY - 2019/2/1
Y1 - 2019/2/1
N2 - We provide model-independent bounds on the rates of rare decays η(η′)→ππ based on experimental limits on the neutron electric dipole moment (nEDM). Starting from phenomenological η(η′)ππ couplings, the nEDM arises at the two-loop level. The leading-order relativistic chiral perturbation theory calculation with the minimal photon coupling to charged pions and a proton inside the loops leads to a finite, counterterm-free result. This is an improvement upon previous estimates which used approximations in evaluating the two-loop contribution and were plagued by divergences. While constraints on the η(η′)ππ couplings in our phenomenological approach are somewhat milder than in the picture with the QCD θ term, our calculation means that whatever the origin of these couplings, the decays η(η′)→2π will remain unobservable in the near future.
AB - We provide model-independent bounds on the rates of rare decays η(η′)→ππ based on experimental limits on the neutron electric dipole moment (nEDM). Starting from phenomenological η(η′)ππ couplings, the nEDM arises at the two-loop level. The leading-order relativistic chiral perturbation theory calculation with the minimal photon coupling to charged pions and a proton inside the loops leads to a finite, counterterm-free result. This is an improvement upon previous estimates which used approximations in evaluating the two-loop contribution and were plagued by divergences. While constraints on the η(η′)ππ couplings in our phenomenological approach are somewhat milder than in the picture with the QCD θ term, our calculation means that whatever the origin of these couplings, the decays η(η′)→2π will remain unobservable in the near future.
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U2 - 10.1103/PhysRevD.99.031703
DO - 10.1103/PhysRevD.99.031703
M3 - Article
AN - SCOPUS:85062608256
VL - 99
JO - Physical Review D
JF - Physical Review D
SN - 2470-0010
IS - 3
M1 - 031703
ER -