Speaker
Description
In the present work, we investigate the hidden-strangeness production process in the $S=+1$ channel via $K^+ p \to K^+ \phi p$, focusing on the exotic pentaquark molecular $K^* \Sigma$ bound-state, assigned by $P_s^+(2071,3/2^-)$. For this purpose, we employ the effective Lagrangian approach in the tree-level Born approximation. Using the experimental and theoretical inputs for the exotic state and for the ground-state hadron interactions, the numerical results show a small but obvious peak structure from Ps+ with the signal-to-background ratio $\approx 1.7\%$, and it is enhanced in the backward-scattering region of the outgoing $K^+$ in the center-of-mass frame. We also find that the contribution from the $K^*(1680,1^-)$ meson plays an important role to reproduce the data. The proton-spin polarizations are taken into account to find a way to reduce the background. The effects of the possible 27-plet pentaquark $\Theta_{27}^{++}$ are discussed as well.
