Excited-state spectroscopy of triply-bottom baryons from lattice QCD

TL;DR

This paper calculates the excited-state spectrum of triply-bottom baryons using lattice QCD, achieving high-precision results that improve understanding of heavy baryon structure and QCD dynamics.

Contribution

It provides the first high-precision lattice QCD calculation of the excited states of triply-bottom baryons, including spin-dependent splittings.

Findings

Ten excited bbb states energies determined with ~1 MeV uncertainty

Demonstrated improved rotational symmetry at finer lattice spacings

Resolved all spin-dependent energy splittings accurately

Abstract

The spectrum of baryons containing three b quarks is calculated in nonperturbative QCD, using the lattice regularization. The energies of ten excited bbb states with J^P = 1/2^+, 3/2^+, 5/2^+, 7/2^+, 1/2^-, and 3/2^- are determined with high precision. A domain-wall action is used for the up-, down- and strange quarks, and the bottom quarks are implemented with NRQCD. The computations are done at lattice spacings of a \approx 0.11 fm and a \approx 0.08 fm, and the results demonstrate the improvement of rotational symmetry as a is reduced. A large lattice volume of (2.7 fm)^3 is used, and extrapolations of the bbb spectrum to realistic values of the light sea-quark masses are performed. All spin-dependent energy splittings are resolved with total uncertainties of order 1 MeV, and the dependence of these splittings on the couplings in the NRQCD action is analyzed.