Timelike electromagnetic kaon form factor

We compute the electromagnetic charged kaon form factor in the timelike region by employing a Poincare ' covariant formalism of the Bethe-Salpeter equation to study quark-antiquark bound states in conjunction with the Schwinger-Dyson equation for the quark propagator. Following a recent kindred calculation of the timelike electromagnetic pion form factor, we include the most relevant intermediate composite particles permitted by their quantum numbers in the interaction kernel to allow for a decay mechanism for the resonances involved. This term augments the usual gluon mediated interaction between quarks. For a sufficiently low energy timelike probing photon, the electromagnetic form factor is saturated by the rho(770) and 0(1020) resonances. We assume SU(2) isospin symmetry throughout. Our results for the absolute value squared of the electromagnetic form factor agree qualitatively rather well and quantitatively moderately so with available experimental data.

Automated summary

In this study, we use a Poincare covariant formalism of the Bethe-Salpeter equation and the Schwinger-Dyson equation for the quark propagator to calculate the electromagnetic charged kaon form factor in the timelike region. By including the relevant intermediate composite particles allowed by their quantum numbers in the interaction kernel, we account for the decay mechanism for the resonances involved. This adds to the usual gluon mediated interaction between quarks. Our results qualitatively agree well and quantitatively moderately agree with available experimental data for the absolute value squared of the electromagnetic form factor.