Effect of the magnetic dipole moment of the vector meson $K^{\ast}$ on the process $e^+ e^- \to K^+ K^- \ 2\pi^0$

Vector mesons possess $2s+1$ electromagnetic properties (where $s=1$ is their spin). Specifically, these are the electric charge, the magnetic dipole moment (MDM), and the electric quadrupole moment (EQM). Among these, only the electric charge is experimentally well-determined due to charge conservation laws; the remaining multipoles are merely estimated using effective QCD models, for which no experimental counterpart currently exists. One approach to determine the $K^{\ast}$ meson’s MDM is to study the $e^+ e^- \to K^+ K^- \ 2\pi^0$ process, analogous to the method used for the $W$ gauge boson in $e^+ e^- \to 4 \ \text{leptons}$ reactions. In this work, we investigate this process in the low-energy regime. We propose to evaluate the sensitivity of the $e^+ e^- \to K^+ K^- \ 2\pi^0$ cross-section to the MDM, incorporating all relevant intermediate channels to describe the cross-section, as measured by BaBar, and explore whether it is possible to obtain, for the first time, a value for the magnetic dipole moment of the $K^{\ast}$ meson.

luisalbertojp@estudiantes.fisica.unam.mx

Luis Alberto Jiménez Pérez