The K^- p to f₁(1285) Λ reaction within an effective Lagrangian approach

The production of the $f_1(1285)$ resonance in the reaction of $K^- p \to f_1(1285) \Lambda$ is studied within an effective Lagrangian approach. The production process is described by the $t$ channel $K^{*+}$ meson exchange. My theoretical approach is based on the results of chiral unitary theory where the $f_1(1285)$ resonance is dynamically generated from the single channel $\bar{K} K^* - c.c.$ interaction. The total and differential cross sections of the $K^- p \to f_1(1285) \Lambda$ reaction are evaluated. Within the coupling constant of the $f_1(1285)$ to $\bar{K}K^*$ channel obtained from the chiral unitary theory and a cut off parameter $\Lambda_c \sim 1.5$ GeV in the form factors, the experimental measurement can be reproduced. This production process would provide further evidence for the $\bar{K} K^* - c.c.$ nature of the $f_1(1285)$ state.