Nucleon, $\Delta$ and $\Omega$ excited states in $N_f=2+1$ lattice QCD

Understand

The energies of the excited states of the Nucleon, $\Delta$ and $\Omega$ are computed in lattice QCD, using two light quarks and one strange quark on anisotropic lattices.

• The calculation is performed at three values of the light quark mass, corresponding to pion masses $m_{\pi}$ = 392(4), 438(3) and 521(3) MeV.
• We employ the variational method with a large basis of interpolating operators enabling six energies in each irreducible representation of the lattice to be distinguished clearly.
• We compare our calculation with the low-lying experimental spectrum, with which we find reasonable agreement in the pattern of states.