Determination of the possible quantum numbers for the newly observed $\Xi_b(6227)^0$ state

TL;DR

This paper analyzes the quantum numbers of the newly observed $ ext{Xi}_b(6227)^0$ baryon, suggesting it is likely a $1P$ excited state based on mass and decay width calculations.

Contribution

It provides a combined analysis of mass sum rules and decay widths to determine the quantum state of $ ext{Xi}_b(6227)^0$, which is a novel approach in this context.

Findings

Mass sum rules are inconclusive alone for quantum number determination.

Decay width calculations support $ ext{Xi}_b(6227)^0$ as a $1P$ excited state.

Results align with experimental data for the $1P$ excitation hypothesis.

Abstract

The LHCb Collaboration recently reported the observation of a new excited bottom baryon $\Xi_b(6227)^0$ and announced an improvement in the measurements related to the previously observed $\Xi_b(6227)^-$ state. We conduct an analysis for $\Xi_b(6227)^0$ state considering it as isospin partner of the $\Xi_b(6227)^-$ resonance and possibly $1P$ or $2S$ excited state with spin $J=\frac{3}{2}$. The corresponding masses for both possibilities have consistent results with the experimental data, indicating that only with the mass sum rules, one can not make exact decision on the nature and quantum numbers of this state. To go further, the decays of these possible excited states to $\Xi_b^- \pi^+$ final state are also considered and the relevant strong coupling constants are extracted from the light cone sum rules. The obtained decay width values support the possibility of $\Xi_b(6227)^0$ to be the $1P$ excited state of $\Xi_b(5945)^0$ baryon.