Interpretation of excited $\Omega_b$ signals

TL;DR

This paper interprets recent LHCb signals of excited $\\Omega_b$ baryons as bound states of a $b$-quark and a $P$-wave $ss$-diquark, predicting their spins, parities, and masses, and compares with previous $\\Omega_c$ findings.

Contribution

It provides a detailed theoretical interpretation of the excited $\\Omega_b$ signals, predicting their quantum numbers and masses, and discusses alternative state configurations.

Findings

Predicted five possible spin and parity states for the excited $\\Omega_b$ baryons.

Identified likely spins 1/2 and 3/2 for the observed states.

Provided mass ranges for the unobserved spin 5/2 state.

Abstract

Recently LHCb reported the discovery of four extremely narrow excited $\Omega_b$ baryons decaying into $\Xi_b^0 K^-$. We interpret these baryons as bound states of a $b$-quark and a $P$-wave $ss$-diquark. For such a system there are exactly five possible combinations of spin and orbital angular momentum. We predict two of spin 1/2, two of spin 3/2, and one of spin 5/2, all with negative parity. We favor identifying the observed states as those those with spins 1/2 and 3/2, and give a range of predicted masses for the one with spin 5/2. We update earlier predictions for these states based on the five narrow excited $\Omega_c$ states reported by LHCb. An alternative picture of the states in which one of $J=1/2$ is extremely wide and hence not seen by LHCb is discussed.