First observation of the hidden-charm pentaquarks on lattice

TL;DR

This study uses lattice QCD to observe bound states in the $ ext{Σ}_c ar{ ext{D}}$ and $ ext{Σ}_c ar{ ext{D}}^*$ channels, providing evidence for hidden-charm pentaquarks related to experimentally observed states.

Contribution

First lattice QCD calculation demonstrating bound states corresponding to hidden-charm pentaquarks near experimental masses.

Findings

Bound states found in both channels near experimental pentaquark masses

Binding energies of approximately 6-7 MeV with quantified errors

Results support the interpretation of observed pentaquarks as molecular states

Abstract

The s-wave scattering of $\Sigma_c \bar{D}$ and $\Sigma_c \bar{D}^*$ in the $I(J^P) = \frac{1}{2}(\frac{1}{2}^-)$ channel is calculated in lattice QCD using two ensembles with different volumes but the same lattice spacing $a\sim 0.08\mathrm{fm}$ and pion mass $M_\pi \sim 294\mathrm{MeV}$. The scattering amplitudes near threshold are obtained by L\"uscher's finite volume method. We find bound state poles in both $\Sigma_c \bar{D}$ and $\Sigma_c \bar{D}^*$ channels, which are possibly related to the $P_c(4312)$ and $P_c(4440) / P_c(4457)$ pentaquarks observed in experiments. The binding energy is $6(2)(2)$MeV for $\Sigma_c \bar{D}$ and $7(3)(1)$MeV for $\Sigma_c \bar{D}^*$, where the first error is the statistical error and the second is the systematic error due to the lattice artifacts.