Interpretations of the new LHCb P_c(4337)^+ pentaquark state

Abstract

Recently the LHCb Collaboration has observed a new pentaquark state, the P_c(4337)^+. Owing to its proximity to the chi _{c0}(1S) p, {bar{D}}^* varLambda _c, {bar{D}} varSigma _c and {bar{D}} varSigma _c^* thresholds, this new pentaquark might very well be a meson–baryon bound state. However its spin and parity have not been determined yet and none of the previous possibilities can be ruled out.We briefly explore a few of these options and the consequences they entail in the present manuscript: (i) the P_c(4337)^+ might be a chi _{c0}(1S) p bound state, (ii) the P_c(4312)^+ and P_c(4337)^+ might be {bar{D}}^* varLambda _c and {bar{D}} varSigma _c states close to threshold, respectively, where the Breit–Wigner mass might not correspond to the location of the poles, (iii) the locations of the P_c(4312)^+ and P_c(4337)^+ might be explained in terms of the {bar{D}}^* varLambda _c-{bar{D}} varSigma _c and {bar{D}}^* varLambda _c-{bar{D}} varSigma _c^* coupled channel dynamics. This last option, though not the most probable explanation, is still potentially compatible with the double peak solution of the P_{cs}(4459)^0 and with what we know of the P_c(4312)^+. As a byproduct of the previous explorations, we conjecture the existence of a series of anticharmed meson – antitriplet charmed baryon bound states and calculate their masses.