Fine Structure of the QCD String Spectrum

Juge, K. Jimmy; Kuti, Julius; Morningstar, Colin

Fine Structure of the QCD String Spectrum

Authors

Juge, K. Jimmy

Kuti, Julius

Morningstar, Colin

Description

Using advanced lattice methods in Quantum Chromodynamics, three distinct scales are established in the excitation spectrum of the gluon field around a static quark-antiquark pair as the color source separation R is varied. On the shortest length scale, the excitations are consistent with states created by local gluon field operators arising from a multipole operator product expansion. An intermediate crossover region below 2 fm is identified with a dramatic rearrangement of the level orderings. On the largest length scale of 2-3 fm, the spectrum agrees with that expected for string-like excitations. The energies nearly reproduce asymptotic pi/R string gaps, but exhibit a fine structure, providing important clues for developing an effective bosonic string description.
4 pages, 3 figures, RevTeX4 (final version accepted for publication)