The string spectrum from large Wilson loops
Pushan Majumdar
TL;DR
The paper investigates the hadronic string spectrum in 2+1D SU(2) lattice gauge theory by constructing Wilson-loop–based correlation matrices to access low-lying states. It employs the Lüscher-Weisz multilevel algorithm to measure exponentially small Wilson loops at large time separations, enabling finite-$T$ extrapolations needed to compare with string predictions. By classifying string states into parity/charge-conjugation channels and extracting energies from Polyakov-loop and Wilson-loop correlators, the study finds overall agreement with the expected $\Delta E_n = \frac{n\pi}{r}$ behavior and the universal Lüscher term after corrections, while highlighting the importance of continuum extrapolation and larger distances. The work demonstrates the viability and limitations of current lattice techniques for testing hadronic-string dynamics and lays groundwork for more precise continuum analyses.
Abstract
We look at energies of the low lying states of the hadronic string in three dimensional SU(2) lattice gauge theory by forming correlation matrices among different sources. We are able to go to previously inaccessible time separations. This is made possible by using a new algorithm proposed by Lüscher and Weisz which lets us measure the exponentially small values of large Wilson loops with sufficient accuracy.