Interpretation of the LHCb $P_c(4312)^+$ Signal

Abstract

We study the nature of the new signal reported by LHCb in the $J\psi p$ spectrum. Based on the $S$-matrix principles, we perform a minimum-bias analysis of the underlying reaction amplitude, focusing on the analytic properties that can be related to the microscopic origin of the $P_c(4312)^+$ peak. By exploring several amplitude parametrizations, we find evidence for the attractive effect of the $\Sigma_c^+ \bar{D}^0$ channel, which is not strong enough, however, to form a bound state.