Interpretation of the LHCb Pc (4312)+ Signal

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)(D) over bar (0) channel, which is not strong enough, however, to form a bound state.