Pentaquarks from intrinsic charms in ${\Lambda }_b$ decays

Abstract

We study the three-body ${\Lambda }_b$ decays of ${\Lambda }_b\to J/\psi pM$ with $M=K^{-}$ and ${\pi }^{-}$. The two new states ${\mathcal{P}}_{c1}\equiv {\mathcal{P}}_c(4380{)}^{+}$ and ${\mathcal{P}}_{c2}\equiv {\mathcal{P}}_c(4450{)}^{+}$ observed recently as the resonances in the $J/\psi p$ invariant mass spectrum of ${\Lambda }_b\to J/\psi p{K}^{-}$ can be identified to consist of five quarks, $uudc\bar{c}$, being consistent with the existence of the pentaquark states. We argue that, in the doubly charmful ${\Lambda }_b$ decays of ${\Lambda }_b\to J/\psi p{K}^{-}$ through $b\to c\bar{c}s$, apart from those through the non-resonant ${\Lambda }_b\to p{K}^{-}$ and resonant ${\Lambda }_b\to {\Lambda }^{\ast }\to p{K}^{-}$ transitions, the third contribution with the non-factorizable effects is not the dominant part for the resonant ${\Lambda }_b\to K^{-}{\mathcal{P}}_{c1,c2},{\mathcal{P}}_{c1,c2}\to J/\psi p$ processes, such that we propose that the ${\mathcal{P}}_{c1,c2}$ productions are mainly from the charmless ${\Lambda }_b$ decays through $b\to \bar{u}us$, in which the $c\bar{c}$ content in ${\mathcal{P}}_{c1,c2}$ arises from the intrinsic charms within the ${\Lambda }_b$ baryon. We hence predict the observables related to the branching ratios and the direct CP violating asymmetries to be $\mathcal{B}({\Lambda }_b\to {\pi }^{-}({\mathcal{P}}_{c1,c2}\to )J/\psi p)/\mathcal{B}({\Lambda }_b\to K^{-}({\mathcal{P}}_{c1,c2}\to )J/\psi p)=0.8\pm 0.1$, ${\mathcal{A}}_{CP}({\Lambda }_b\to {\pi }^{-}({\mathcal{P}}_{c1,c2}\to )J/\psi p)=(-3.9\pm 0.2)\%$, and ${\mathcal{A}}_{CP}({\Lambda }_b\to K^{-}({\mathcal{P}}_{c1,c2}\to )J/\psi p)=(5.8\pm 0.2)\%$, which can alleviate the inconsistency between the theoretical expectations from the three contributions in the doubly charmful ${\Lambda }_b$ decays and the observed data.

10 pages, 2 figures, revised version accepted by PLB

References in corpus (10)

• Big-Bang Nucleosynthesis
• Observation of $J/\psi p$ resonances consistent with pentaquark states in ${\Lambda }_b^0\to J/\psi K^{-}p$ decays
• New Exotic Meson and Baryon Resonances from Doubly-Heavy Hadronic Molecules
• Identifying exotic hidden-charm pentaquarks
• Formation of hidden-charm pentaquarks in photon-nucleon collisions
• Photoproduction of hidden charm pentaquark states $P_c^{+}(4380)$ and $P_c^{+}(4450)$
• Direct CP violation in ${\Lambda }_b$ decays
• Charmful Three-body Baryonic B decays
• Direct CP violation in $B^{\pm }\to p\bar{p}{K}^{(\ast )\pm }$
• Role of "Intrinsic Charm" in Semi-Leptonic B-Meson Decays

Cited by in corpus (22)

• The hidden-charm pentaquark and tetraquark states
• Evidence for exotic hadron contributions to ${\Lambda }_b^0\to J/\psi p{\pi }^{-}$ decays
• The ${\Lambda }_b\to J/\psi K^0\Lambda$ reaction and a hidden-charm pentaquark state with strangeness
• Strong decay mode $J/\psi p$ of hidden charm pentaquark states $P_c^{+}(4380)$ and $P_c^{+}(4450)$ in ${\Sigma }_c{\bar{D}}^{\ast }$ molecular scenario
• Coupled channel analysis of molecule picture of $P_c(4380)$
• QCD sum rule study of hidden-charm pentaquarks
• Hidden-charm pentaquarks and their hidden-bottom and $B_c$-like partner states
• A hidden-charm pentaquark state in ${\Lambda }_b^0\to J/\psi p{\pi }^{-}$ decay
• Confronting pentaquark photoproduction with new LHCb observations
• Do the $P_c^{+}$ Pentaquarks Have Strange Siblings?
• Fully charmed tetraquarks from LHC to FCC: Natural stability from fragmentation
• Revisiting hidden-charm pentaquarks from QCD sum rules
• Parton distribution functions and constraints on the intrinsic charm content of the proton using BHPS approach
• Study of two-body doubly charmful baryonic $B$ decays with $SU(3)$ flavor symmetry
• Hidden-charm Pentaquark Production at $e^{+}{e}^{-}$ Colliders
• Search for $XYZ$ states in ${\Lambda }_b$ decays at the LHCb
• Pentaquarks in semileptonic ${\Lambda }_b$ decays
• Roles of scalar mesons in charmless ${\Lambda }_b$ decays
• Hidden charm ${\mathcal{P}}_{cs}(4338{)}^0$ production in baryonic $B^{-}\to J/\psi \Lambda \bar{p}$ decay
• Multimodal Fragmentation of All-Heavy Pentaquarks: Uncertainty-Aware Predictions for Hadron Colliders
• Quantum Numbers of the Pentaquark States $P_c^{+}$ via Symmetry Analysis
• Heavy-flavor multimodal fragmentation to $S$-wave pentacharms at next-generation hadron colliders