Interpretation of excited <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi mathvariant="normal">Ω</mml:mi><mml:mi>b</mml:mi></mml:msub></mml:math> signals
Marek Karliner, Jonathan L. Rosner
Abstract
Recently LHCb reported the discovery of four extremely narrow excited ${\mathrm{\ensuremath{\Omega}}}_{b}$ baryons decaying into ${\mathrm{\ensuremath{\Xi}}}_{b}^{0}{K}^{\ensuremath{-}}$. 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 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 ${\mathrm{\ensuremath{\Omega}}}_{c}$ 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.