Searching for a $P_{cs}(4200)$ state in the ${\Lambda }_b\to \varphi {\eta }_c\Lambda$ reaction

Abstract

We propose the ${\Lambda }_b\to \varphi {\eta }_c\Lambda$ reaction to observe a $P_{cs}$ state around $4200$ MeV, predicted at lower masses than expected from comparison with the $P_c$ states, stemming as a consequence of the important role played by coupled channels in the $P_{cs}$ case, which does not appear in the $P_c$ case. That state decays to ${\eta }_c\Lambda$ with a width of about $200$ keV. The reaction is related to ${\Lambda }_b^0\to \varphi D_s^{-}{\Lambda }_c^{+}$, which has already been observed. We predict a branching fraction for ${\Lambda }_b\to \varphi P_{cs}(4200)$; $P_{cs}\to {\eta }_c\Lambda$ of the order of $10^{-5}$, which is within present capabilities of the LHCb collaboration. The observation of this state would bring valuable light on the nature of the $P_c$ and $P_{cs}$ states and the role played by coupled channels in hadron structure and hadron reactions.

7 pages, 6 figures

References in corpus (18)

• Pentaquark and Tetraquark states
• Observation of a narrow pentaquark state, $P_c(4312{)}^{+}$, and of two-peak structure of the $P_c(4450{)}^{+}$
• An updated review of the new hadron states
• Exotics: Heavy Pentaquarks and Tetraquarks
• Observation of an exotic narrow doubly charmed tetraquark
• Study of the doubly charmed tetraquark $T_{cc}^{+}$
• Study of $P_c(4457)$, $P_c(4440)$, and $P_c(4312)$ in a quasipotential Bethe-Salpeter equation approach
• Observation of a $J/\psi \Lambda$ resonance consistent with a strange pentaquark candidate in $B^{-}\to J/\psi \Lambda \bar{p}$ decays
• Anatomy of the newly observed hidden-charm pentaquark states: $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$
• Evidence for a new structure in the $J/\psi p$ and $J/\psi \bar{p}$ systems in $B_s^0\to J/\psi p\bar{p}$ decays
• Revisiting the nature of the $P_c$ pentaquarks
• Systematics of the heavy flavor hadronic molecules
• Coupled-channel effects of the ${\Sigma }_c^{(\ast )}{\bar{D}}^{(\ast )}$-${\Lambda }_c(2595)\bar{D}$ system and molecular nature of the $P_c$ pentaquark states from one-boson exchange model
• A new look at the $P_{cs}$ states from a molecular perspective
• Strange hidden-charm $P_{\psi s}^{\Lambda }(4459)$ and $P_{\psi s}^{\Lambda }(4338)$ pentaquarks and additional $P_{\psi s}^{\Lambda }$, $P_{\psi s}^{\Sigma }$ and $P_{\psi ss}^N$ candidates in a quark model approach
• The double thresholds distort the lineshapes of the $P_{\psi s}^{\Lambda }(4338{)}^0$ resonance
• How to reveal the nature of three or more pentaquark states?
• $P_c$ states and their open-charm decays with the complex scaling method