High Energy String Collisions in a Compact Space

TL;DR

This paper demonstrates that high energy string scattering amplitudes in a compact space can shift from exponential suppression to power-law behavior under specific conditions, revealing new insights into string interactions in compactified dimensions.

Contribution

It shows that certain kinematic configurations in compact spaces lead to power-law scattering amplitudes, contrasting with the usual exponential fall-off, and highlights the role of worldsheet duality.

Findings

Amplitudes become power-law in specific compact configurations.

Exponential suppression disappears for certain fixed-angle scatterings.

Worldsheet duality governs the transition in amplitude behavior.

Abstract

When high energy strings scatter at fixed angle, their amplitudes characteristically fall off exponentially with energy, ${\cal A} \sim \exp(-s \times const.)$. We show that in a compact space this suppression disappears for certain kinematic configurations. Amplitudes are power-law behaved and therefore greatly enhanced. In spacetime this corresponds to fixed-angle scattering, with fixed transfer in the compact dimensions. On the worldsheet this process is described by a stationary configuration of effective charges and vortices with vanishing total energy. It is worldsheet duality---and not spacetime duality---that plays a role.