Holographic charm and bottom pentaquarks I: Mass spectra with spin effects

TL;DR

This paper uses holographic duality to analyze and predict the mass spectra of non-strange charm and bottom pentaquarks, incorporating spin effects and providing results consistent with recent LHCb findings.

Contribution

It introduces a holographic model for pentaquarks that naturally includes spin effects and predicts new heavy pentaquark states, improving upon molecular models.

Findings

Spin-spin and spin-orbit couplings derived from heavy quark mass expansion.

Internal heavy quark spin degeneracy lifted, matching experimental data.

Predictions of new charm and bottom pentaquark states.

Abstract

We revisit the three non-strange pentaquarks $[\frac 12\frac 12^-]_{S=0,1}$ and $[\frac 12\frac 32^-]_{S=1}$ predicted using the holographic dual description, where chiral and heavy quark symmetry are manifest in the triple limit of a large number of colors, large quark mass and strong $^\prime$t Hooft gauge coupling. In the heavy quark limit, the pentaquarks with internal heavy quark spin $S$ are all degenerate. The holographic pentaquarks are dual to an instanton bound to heavy mesons in bulk, without the shortcomings related to the nature of the interaction and the choice of the hard core inherent to the molecular constructions. We explicitly derive the spin-spin and spin-orbit couplings arising from next to leading order in the heavy quark mass, and lift totally the internal spin degeneray, in fair agreement with the newly reported charmed pentaquarks from LHCb. New charm and bottom pentaquark states are predicted.