Direct Production of Lightest Regge Resonances

TL;DR

This paper develops a framework for directly producing and calculating the amplitudes of lightest Regge excitations in superstring theory, with applications to potential LHC phenomenology involving low-mass strings and extra dimensions.

Contribution

It constructs covariant vertex operators for universal Regge states and evaluates relevant scattering amplitudes for collider phenomenology.

Findings

Derived explicit amplitudes for Regge state production

Tabulated partonic cross sections for key processes

Facilitates experimental searches for string excitations at colliders

Abstract

We discuss direct production of Regge excitations in the collisions of massless four-dimensional superstring states, focusing on the first excited level of open strings ending on D-branes extending into higher dimensions. We construct covariant vertex operators and identify ``universal'' Regge states with the internal parts either trivial or determined by the world-sheet SCFT describing superstrings propagating on an arbitrary Calabi-Yau manifold. We evaluate the amplitudes involving one such massive state and up to three massless ones and express them in the helicity basis. The most important phenomenological applications of our results are in the context of low-mass string (and large extra dimensions) scenarios in which excited string states are expected to be produced at the LHC as soon as the string mass threshold is reached in the center-of-mass energies of the colliding partons. In order to facilitate the use of partonic cross sections, we evaluate them and tabulate for all production processes: gluon fusion, quark absorbing a gluon, quark-antiquark annihilation and quark-quark scattering.