Spectroscopy of doubly and triply-charmed baryons from lattice QCD

TL;DR

This paper uses lattice QCD to compute the spectra of doubly and triply-charmed baryons, revealing detailed energy levels, spin states, and mass splittings, and providing predictions for unmeasured baryon masses.

Contribution

It introduces a comprehensive lattice QCD approach with novel computational techniques to analyze excited states and energy splittings of heavy baryons, aligning results with symmetry expectations and making new mass predictions.

Findings

Baryonic states with spins up to 7/2 identified

Energy splittings match SU(6)×O(3) symmetry expectations

Predicted mass of Ω_ccb baryon is approximately 8050 MeV

Abstract

We present the ground and excited state spectra of doubly and triply-charmed baryons by using lattice QCD with dynamical clover fermions. A large set of baryonic operators that respect the symmetries of the lattice and are obtained after subduction from their continuum analogues are utilized. Using novel computational techniques correlation functions of these operators are generated and the variational method is exploited to extract excited states. The lattice spectra that we obtain have baryonic states with well-defined total spins up to 7/2 and the low lying states remarkably resemble the expectations of quantum numbers from SU(6) $\otimes$ O(3) symmetry. Various energy splittings between the extracted states, including splittings due to hyperfine as well as spin-orbit coupling, are considered and those are also compared against similar energy splittings at other quark masses. Using those splittings for doubly-charmed baryons, and taking input of experimental $B_c$ meson mass, we predict the mass splittings of $B^*_c - B_c$ to be about 80 $\pm$ 8 MeV and $m_{\Omega_{ccb}} = 8050\pm10$ MeV.