Hypernuclear production by ($\gamma, K^+$) reaction within a relativistic model

Within a fully covariant model based on an effective Lagrangian picture, we investigate the hypernuclear production in photon-nucleus interaction on $^{16}$O target. The explicit kaon production vertex is described via creation, propagation and decay into relevant channel of $N^*$(1650), $N^*$(1710), and $N^*$(1720) intermediate baryonic resonance states in the initial interaction of the incident photon with one of the target protons. Bound state nucleon and hyperon wave functions are obtained by solving the Dirac equation. Using vertex parameters determined in the previous studies, contributions of the $N^*$(1710) baryonic resonance dominate the total production cross sections which are found to peak at photon energies below 1 GeV. The results show that photoproduction is the most appropriate means for studying the unnatural parity hypernuclear states, thus accessing the spin dependence of the hyperon-nucleon interaction.