The LHCb state $P_{\psi s}^{\Lambda }(4338)$ as a triangle singularity

Abstract

We present a model for the $J/\psi \Lambda$ spectrum in $B^{-}\to J/\psi \Lambda \bar{p}$ decays, including the $P_{\psi s}^{\Lambda }(4338)$ baryon recently observed by the LHCb collaboration. We assume production via triangle diagrams which couple to the final state via non-perturbative interactions which are constrained by heavy-quark and $S{U}_3$-flavor symmetry. The bulk of the distribution is described by a triangle diagram with a color-favored electroweak vertex, while the sharp $P_{\psi s}^{\Lambda }(4338)$ enhancement is due to the triangle singularity in another diagram featuring a $1/2^{-}$ baryon consistent with ${\Sigma }_c(2800)$. We predict a comparable $P_{\psi s}^{\Lambda }(4338)$ signal in ${\eta }_c\Lambda$, and anticipate possible large isospin mixing effects through decays to $J/\psi {\Sigma }^0$ and ${\eta }_c{\Sigma }^0$

14 pages, 2 figures

References in corpus (2)

• Anatomy of the newly observed hidden-charm pentaquark states: $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$
• Experimental constraints on the properties of $P_c$ states

Cited by in corpus (13)

• Chiral perturbation theory for heavy hadrons and chiral effective field theory for heavy hadronic molecules
• Pole determination of $P_{\psi s}^{\Lambda }(4338)$ and possible $P_{\psi s}^{\Lambda }(4255)$ in $B^{-}\to J/\psi \Lambda \bar{p}$
• Spectrum of the molecular pentaquarks
• $P_{\psi s}^{\Lambda }(4459)$ and $P_{\psi s}^{\Lambda }(4338)$ as molecular states in $J/\psi \Lambda$ invariant mass spectra
• Surveying the mass spectra and the electromagnetic properties of the ${\Xi }_c^{(\prime ,\ast )}{D}^{(\ast )}$ molecular pentaquarks
• Higher molecular $P_{\psi s}^{\Lambda /\Sigma }$ pentaquarks arising from the ${\Xi }_c^{(\prime ,\ast )}{\bar{D}}_1/{\Xi }_c^{(\prime ,\ast )}{\bar{D}}_2^{\ast }$ interactions
• Unveiling the Structure of Hidden-Bottom Strange Pentaquarks via Magnetic Moments
• Production mechanism of hidden-charm pentaquark states $P_{c\bar{c}s}$ with strangeness $S=-1$
• Molecular $P_{\psi }$ pentaquarks from light-meson exchange saturation
• Possible molecules of triple-heavy pentaquarks within the extended local hidden gauge formalism
• Hidden charm ${\mathcal{P}}_{cs}(4338{)}^0$ production in baryonic $B^{-}\to J/\psi \Lambda \bar{p}$ decay
• Strong decays of the $P_{cs}(4338)$ and its high isospin cousin via the QCD sum rules
• Exotic hadrons associated with $b$-quark