Quantum corrections from a path integral over reparametrizations

TL;DR

This paper investigates a path integral approach to Wilson loops in large-N QCD, capturing quantum corrections like the L"uscher term across different dimensions through semiclassical analysis and modifications of the ansatz.

Contribution

It demonstrates how a semiclassical expansion of the path integral over reparametrizations reproduces the L"uscher term in various dimensions and proposes a modified ansatz for broader applicability.

Findings

Reproduces the L"uscher term in d=26 dimensions

Proposes a modified ansatz for other dimensions

Verifies results through direct Laplace operator determinant calculation

Abstract

We study the path integral over reparametrizations that has been proposed as an ansatz for the Wilson loops in the large-$N$ QCD and reproduces the area law in the classical limit of large loops. We show that a semiclassical expansion for a rectangular loop captures the L\"uscher term associated with $d=26$ dimensions and propose a modification of the ansatz which reproduces the L\"uscher term in other dimensions, which is observed in lattice QCD. We repeat the calculation for an outstretched ellipse advocating the emergence of an analog of the L\"uscher term and verify this result by a direct computation of the determinant of the Laplace operator and the conformal anomaly.