Hunting for TeV Scale Strings at the LHC

TL;DR

This paper reviews historical and recent approaches to detecting TeV scale strings at the LHC, emphasizing a model-independent parametrization of scattering amplitudes and cross sections for Standard Model particles.

Contribution

It revisits and makes accessible decades-old phenomenological models of TeV scale strings, connecting them with modern motivations like D-branes and large extra dimensions.

Findings

Resonance predictions consistent with string behavior

Matching low-energy effective field theory with string-inspired models

Historical models are relevant for current LHC searches

Abstract

In this paper I review the possibility of TeV scale strings that may be detectable by the Large Hadron Collider (LHC). This possibility was investigated extensively in a series of phenomenological papers during 1984-1985 in connection with the Superconducting Super Collider (SSC). The work was mainly based on a model independent systematic parametrization of scattering amplitudes and cross sections, for Standard Model particles, quarks and leptons, that were assumed to behave like strings, while gluons, photons, $W^{\pm},Z$ were taken as elementary. By using Veneziano type beta functions consistent with crossing symmetry, duality and Regge behavior, bosonic or fermionic resonances in each channel were included, while the low energy behavior was matched to effective field theory non-renormalizable interactions consistent with the Standard Model SU(3)xSU(2)xU(1) gauge symmetry as well as global flavor and family symmetries. The motivation for this approach at that time was the possible compositeness of quarks and leptons but the same phenomenological approach would apply effectively with the modern additional motivations for TeV scale strings, such as the hypothesis of D-branes with large extra dimensions. Because some of the main theoretical and phenomenological work of that time appeared only in the 1984 Snowmass and other proceedings, the results of the investigations have been inaccessible to most researchers and consequently have been largely forgotten. Meanwhile similar approaches are being explored by other researchers. Given the renewed interest in the old results, the purpose of the current paper is to make them readily available.