Quantizing the rotating string with massive endpoints

TL;DR

This paper calculates quantum corrections to the Regge trajectory of a rotating string with massive endpoints, incorporating semiclassical quantization, divergence renormalization, and spectrum analysis, extending understanding of string models with mass.

Contribution

It provides a detailed semiclassical quantization framework for rotating strings with massive endpoints, including divergence renormalization and spectrum analysis, which was not previously established.

Findings

The intercept receives contributions from transverse and rotational modes.

The intercept converges to known massless results in the limit.

Explicit corrections are calculated for long strings with massive endpoints.

Abstract

We compute leading order quantum corrections to the Regge trajectory of a rotating string with massive endpoints using semiclassical methods. We expand the bosonic string action around a classical rotating solution to quadratic order in the fluctuations and perform the canonical quantization of the resulting theory. For a rotating string in $D$ dimensions the intercept receives contributions from $D-3$ transverse modes and one mode in the plane of rotation, in addition to a contribution due to the Polchinski-Strominger term of the non-critical effective string action when $D\neq26$. The intercept at leading order is proportional to the expectation value of the worldsheet Hamiltonian of the fluctuations, and this is shown explicitly in several cases. All contributions to the intercept are considered, and we show a simple physical method to renormalize the divergences in them. The intercept converges to known results at the massless limit, and corrections from the masses are explicitly calculated at the long string limit. In the process we also determine the quantum spectrum of the string with massive endpoints, and analyze the asymmetric case of two different endpoint masses.