A closer look at string resonances in dijet events at the LHC

TL;DR

This paper explores how low-scale string theories could produce observable dijet resonances at the LHC, focusing on the unique properties of string excited states and their angular distributions.

Contribution

It analyzes the distinctive resonance structures and potential mass shifts of string excited states, proposing methods to identify low-scale string signatures at the LHC.

Findings

String resonances can produce nearly degenerate states forming a single resonance.

Mass shifts of color singlet states may occur due to one-loop effects and mixing.

Resonance shape distortions could be observable with jet flavor discrimination.

Abstract

The first string excited state can be observed as a resonance in dijet invariant mass distributions at the LHC, if the scenario of low-scale string with large extra dimensions is realized. A distinguished property of the dijet resonance by string excited states from that the other "new physics" is that many almost degenerate states with various spin compose a single resonance structure. It is examined that how we can obtain evidences of low-scale string models through the analysis of angular distributions of dijet events at the LHC. Some string resonance states of color singlet can obtain large mass shifts through the open string one-loop effect, or through the mixing with closed string states, and the shape of resonance structure can be distorted. Although the distortion is not very large (10% for the mass squared), it might be able to observe the effect at the LHC, if gluon jets and quark jets could be distinguished in a certain level of efficiency.