Dijet signals for low mass strings at the LHC

TL;DR

This paper explores the potential for the Large Hadron Collider to detect low-mass string excitations through dijet signals, providing parameter-free predictions and estimating discovery reach up to 6.8 TeV.

Contribution

It introduces a model-independent method to evaluate string resonance signals at the LHC, focusing on first Regge excitations in D-brane scenarios with TeV-scale string mass.

Findings

LHC can discover string scales up to 6.8 TeV after several years.

Resonant structures in pp → γ + jet can confirm string physics.

Detection possible with as little as 100 pb^{-1} of data.

Abstract

We consider extensions of the standard model based on open strings ending on D-branes, with gauge bosons due to strings attached to stacks of D-branes and chiral matter due to strings stretching between intersecting D-branes. Assuming that the fundamental string mass scale is in the TeV range and the theory is weakly coupled, we discuss possible signals of string physics at the Large Hadron Collider (LHC). In such D-brane constructions, the dominant contributions to full-fledged string amplitudes for all the common QCD parton subprocesses leading to dijets are completely independent of the details of compactification, and can be evaluated in a parameter-free manner. We make use of these amplitudes evaluated near the first resonant pole to determine the discovery potential of LHC for the first Regge excitations of the quark and gluon. Remarkably, the reach of LHC after a few years of running can be as high as 6.8 TeV. Even after the first 100 pb^{-1} of integrated luminosity, string scales as high as 4.0 TeV can be discovered. For string scales as high as 5.0 TeV, observations of resonant structures in pp \to {\rm direct} \gamma + jet can provide interesting corroboration for string physics at the TeV-scale.