Long Lived Large Type II Strings: decay within compactification

TL;DR

This paper investigates the decay rates of long-lived superstring states within compactified dimensions, revealing how decay characteristics vary with compactification radius and wrapping configurations.

Contribution

It provides an exact numerical analysis of superstring decay rates in compactified spaces, extending understanding beyond flat uncompactified scenarios.

Findings

Decay rate approaches uncompactified case for large radii

Decay features depend on wrapping and initial mass

Long-lived states decay mainly via massless radiation

Abstract

Motivated also by recent revival of interest about metastable string states (as cosmic strings or in accelerator physics), we study the decay, in presence of dimensional compactification, of a particular superstring state, which was proven to be remarkably long-lived in the flat uncompactified scenario. We compute the decay rate by an exact numerical evaluation of the imaginary part of the one-loop propagator. For large radii of compactification, the result tends to the fully uncompactified one (lifetime T = const M^5/g^2), as expected, the string mainly decaying by massless radiation. For small radii, the features of the decay (emitted states, initial mass dependence,....) change, depending on how the string wraps on the compact dimensions.