Investigation on the $\Omega(2012)$ from QCD sum rules

Abstract

We investigate the recently observed $\Omega(2012)$ baryon using QCD sum rules. By constructing $P$-wave $\Omega$ baryon currents and performing spin projection and parity projection, we obtain the masses of the $J^P = 1/2^-$ and $3/2^-$ states as $M_{1/2^-} = 2.07^{+0.07}_{-0.07}{\rm~GeV}$ and $M_{3/2^-} = 2.05^{+0.09}_{-0.10}{\rm~GeV}$ in good agreement with experiment. This suggests that $\Omega(2012)$ is likely to be a negative parity $P$-wave excited state, though its spin remains undetermined and requires further study of its decay properties.