Possible pentaquark candidates: new excited $\Omega_c$ states

TL;DR

This paper uses QCD sum rules to predict masses of specific charmed pentaquark states, identifying potential candidates for observed excited $\,Omega_c$ states, and distinguishes positive and negative parity contributions.

Contribution

It provides a detailed QCD sum rule analysis of $J^P=3/2^\,pm$ charmed pentaquark states, including separation of parity states and mass predictions consistent with experimental data.

Findings

Predicted masses of charmed pentaquarks around 3.15 GeV.

Identified compatibility with observed $\,Omega_c$ excited states.

Separated positive and negative parity contributions unambiguously.

Abstract

In this article, we study the axialvector-diquark-scalar-diquark-antiquark type charmed pentaquark states with $J^P={\frac{3}{2}}^\pm$ with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension $13$ in a consistent way. In calculations, we separate the contributions of the negative parity and positive parity pentaquark states unambiguously, and choose three sets input parameters to study the masses and pole residues of the charmed pentaquark states $uuuc\bar{u}$ and $sssc\bar{s}$ in details. Then we estimate the masses of the charmed pentaquark states $ssuc\bar{u}$, $susc\bar{u}$, $ssdc\bar{d}$ and $sdsc\bar{d}$ with $J^P={\frac{3}{2}}^-$ to be $3.15\pm0.13\,\rm{GeV}$ according to the $SU(3)$ breaking effects, which is compatible with the $\Omega_c(3050)$, $\Omega_c(3066)$, $\Omega_c(3090)$, $\Omega_c(3119)$.