In-Medium $K^+$ Electromagnetic Form Factor with a Symmetric Vertex in a Light Front Approach

Abstract

Using the light-front kaon wave function based on a Bethe-Salpeter amplitude model for the quark-antiquark bound state, we study the Electromagnetic Form Factor (EMFF) of the kaon in nuclear medium within the framework of light-front field theory. The kaon model we adopt is well constrained by previous and recent studies to explain its properties in vacuum. The in-medium kaon EMFF is evaluated for the + component of the electromagnetic current, $J^+$, in the Breit frame. In order to consistently incorporate the constituent up and antistrange quarks of the kaon immersed in symmetric nuclear matter, we use the Quark-Meson Coupling (QMC) model, which has been widely applied to various hadronic and nuclear phenomena in a nuclear medium with success. We predict the in-medium modification of the kaon EMFF in symmetric nuclear matter. It is found that, after a fine tuning of the regulator mass, i.e. $m_R = 0.600$ GeV, the model is suitable to fit the available experimental data in vaccum within the theoretical uncertainties, and based on this we predict the in-medium modification of the EMFF.