Spectroscopy of doubly-charmed baryons from lattice QCD

TL;DR

This study uses lattice QCD to compute the spectra of doubly-charmed baryons, revealing detailed excited states and challenging the diquark model, with results aligning with SU(6)X O(3) symmetry expectations.

Contribution

First lattice QCD calculation of doubly-charmed baryon spectra including excited states with detailed spin analysis.

Findings

Lattice spectra show states up to spin 7/2.

Results do not support the diquark picture.

Spectra align with SU(6)X O(3) symmetry models.

Abstract

We present the ground and excited state spectra of doubly charmed baryons from lattice QCD with dynamical quark fields. Calculations are performed on anisotropic lattices of size 16^3 X 128, with inverse spacing in temporal direction 1/a_t = 5.67(4) GeV and with a pion mass of about 390 MeV. A large set of baryonic operators that respect the symmetries of the lattice yet which retain a memory of their continuum analogues are used. These operators transform as irreducible representations of SU(3) symmetry for flavor, SU(4) symmetry for Dirac spins of quarks and O(3) for spatial symmetry. The distillation method is utilized to generate baryon correlation functions which are analysed using the variational fitting method to extract excited states. The lattice spectra obtained have baryonic states with well-defined total spins up to 7/2 and the pattern of low lying states does not support the diquark picture for doubly charmed baryons. On the contrary the calculated spectra are remarkably similar to the expectations from models with an SU(6)X O(3) symmetry. Various spin dependent energy splittings between the extracted states are also evaluated.