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

Abstract

AbstractRecently the LHCb Collaboration has observed a new pentaquark state, the $$P_c(4337)^+$$ P c ( 4337 ) + . Owing to its proximity to the $$\chi _{c0}(1S) p$$ χ c 0 ( 1 S ) p , $${\bar{D}}^* \varLambda _c$$ D ¯ ∗ Λ c , $${\bar{D}} \varSigma _c$$ D ¯ Σ c and $${\bar{D}} \varSigma _c^*$$ D ¯ Σ 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 $$P_c(4337)^+$$ P c ( 4337 ) + might be a $$\chi _{c0}(1S) p$$ χ c 0 ( 1 S ) p bound state, (ii) the $$P_c(4312)^+$$ P c ( 4312 ) + and $$P_c(4337)^+$$ P c ( 4337 ) + might be $${\bar{D}}^* \varLambda _c$$ D ¯ ∗ Λ c and $${\bar{D}} \varSigma _c$$ D ¯ Σ 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 $$P_c(4312)^+$$ P c ( 4312 ) + and $$P_c(4337)^+$$ P c ( 4337 ) + might be explained in terms of the $${\bar{D}}^* \varLambda _c$$ D ¯ ∗ Λ c -$${\bar{D}} \varSigma _c$$ D ¯ Σ c and $${\bar{D}}^* \varLambda _c$$ D ¯ ∗ Λ c -$${\bar{D}} \varSigma _c^*$$ D ¯ Σ c ∗ coupled channel dynamics. This last option, though not the most probable explanation, is still potentially compatible with the double peak solution of the $$P_{cs}(4459)^0$$ P cs ( 4459 ) 0 and with what we know of the $$P_c(4312)^+$$ 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.