Speaker
Dr
Alexey Zhevlakov
(TSU)
Description
Here will be present an improved estimate of the CPV coupling constants of the and 0 mesons to two pions using upper limits from data on the neutron electric dipole moment (nEDM). Using a phenomenological Lagrangian approach based on nonderivative couplings of the pseudoscalar mesons with nucleons, we include the full momentum dependence of the eta-pi-pi or eta-prime-pi-pi couplings in a two-loop approach to the nEDM calculation. Furthermore, this approach enables the inclusion of charged pion loops, therefore allowing for the leading electric photon minimal couplings. The upper limits
for the rates of the CPV decays eta(eta-prime) into pair of pions that we derive are by orders of magnitude more stringent than those from the existing experiments so far.
Summary
An upper limit for the Theta- parameter in the Peccei-Quinn mechanism from the f_{\eta^\prime\pi\pi} constant:
\bar{Theta} < 2.3 \cdot 10^{-9}.
Primary author
Dr
Alexey Zhevlakov
(TSU)
