Speaker
Description
A complete theoretical analysis of the $C$-conserving semileptonic decays $\eta^{(\prime)}\to\pi^0l^+l^-$ and $\eta^\prime\to\eta l^+l^-$ ($l=e$ or $\mu$) is carried out within the framework of the Vector Meson Dominance (VMD) model. An existing phenomenological model is used to parametrise the VMD coupling constants and the associated numerical values are obtained from an optimisation fit to $V\to P\gamma$ and $P\to V\gamma$ radiative decays ($V=\rho^0$, $\omega$, $\phi$ and $P=\pi^0$, $\eta$, $\eta^{\prime}$). The decay widths and dilepton energy spectra for the two $\eta\to\pi^0l^+l^-$ processes obtained using this approach are compared and found to be in good agreement with other results available in the published literature. Theoretical predictions for the four $\eta^{\prime}\to\pi^0l^+l^-$ and $\eta^\prime\to\eta l^+l^-$ decay widths and dilepton energy spectra are calculated and presented for the first time in this work. Finally, the signature of CP violating operators from the SMEFT on experimental observables is investigated and quantified for the $l=\mu$ case.
