Newly discovered $\Xi_c^{0}$ resonances and their parameters

TL;DR

This paper investigates newly observed $ ext{Xi}_c$ resonances, calculating their properties using QCD sum rules, and compares predictions with experimental data to assign quantum numbers and interpret their nature.

Contribution

The study provides the first comprehensive QCD-based analysis of the masses, widths, and quantum numbers of the $ ext{Xi}_c$ resonances, including new excited states.

Findings

$ ext{Xi}_c(2923)^0$ and $ ext{Xi}_c(2939)^0$ are $1P$ excitations of spin-$1/2$ and spin-$3/2$ baryons.

$ ext{Xi}_c(2965)^0$ may be an excited $2S$ state of flavor-sextet or antitriplet baryon.

Predicted masses and widths agree with experimental data, supporting quantum number assignments.

Abstract

The aim of the present article is investigation of the newly observed resonances $\Xi_c(2923)^{0}$, $\Xi_c(2939)^{0}$, and $\Xi_c(2965)^{0}$ which are real candidates to charm-strange baryons. To this end, we calculate the mass and pole residue of the ground-state and excited $1P$ and $2S$ spin-$% 1/2 $ flavor-sextet baryons $\Xi_{c}^{\prime 0}$, $\Xi_{c}^{\prime 0}(1/2^{-})$ and $\Xi_{c}^{\prime 0}(1/2^{+})$ with quark content $csd$, respectively. The masses and pole residues of the ground-state and excited spin-$3/2$ baryons $\Xi_{c}^{\star 0}$ are found as well. Spectroscopic parameters of these particles are computed in the context of the QCD two-point sum rule method. Widths of the excited baryons are evaluated through their decays to final states $\Lambda_{c}^{+}K^{-}$ and $% \Xi_{c}^{\prime 0}\pi$. These processes are explored by means of the full QCD light-cone sum rule method necessary to determine strong couplings at relevant vertices. Obtained predictions for the masses and widths of the four excited baryons, as well as previous results for $1P$ and $2S$ flavor-antitriplet spin-1/2 particles $\Xi_c^{0}$ are confronted with available experimental data on $\Xi_{c}^{0}$ resonances to fix their quantum numbers. Our comparison demonstrates that the resonances $\Xi_c(2923)^{0}$ and $\Xi_c(2939)^{0}$ can be considered as $1P$ excitations of the spin-$1/2$ flavor-sextet and spin-$3/2$ baryons, respectively. The resonance $\Xi _{c}(2965)^{0}$ may be interpreted as the excited $2S$ state of either spin-$% 1/2$ flavor-sextet or antitriplet baryon.