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 Pc(4312)+ peak. By exploring several amplitude parametrizations, we find evidence for the attractive effect of the Sigma_c D0bar channel, which is not strong enough, however, to form a bound state.
Date of publication:
Phys.Rev.Lett. 123 (2019) no.9, 092001