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 ${\chi }_{c0}(1S)p$, ${\bar{D}}^{\ast }{\Lambda }_c$, $\bar{D}{\Sigma }_c$ and $\bar{D}{\Sigma }_c^{\ast }$ 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 ${\bar{D}}^{\ast }{\Lambda }_c$ and $\bar{D}{\Sigma }_c$ 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 ${\bar{D}}^{\ast }{\Lambda }_c$-$\bar{D}{\Sigma }_c$ and ${\bar{D}}^{\ast }{\Lambda }_c$-$\bar{D}{\Sigma }_c^{\ast }$ 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.

Comments: 19 pages, 5 tables, 1 figure, corresponds with published version