Detectability of the second resonance of low-scale string models at the LHC

TL;DR

This paper explores the potential to detect the second resonance of low-scale string models at the LHC by analyzing angular distributions and searching for a second resonance in dijet mass spectra, providing luminosity requirements for confirmation.

Contribution

It introduces two novel analysis methods to identify string resonances and their degeneracies at the LHC, focusing on the second excited states and their characteristic mass ratios.

Findings

Higher spin degeneracy can be observed through angular distributions.

Second string excited states can be identified as a second resonance.

Luminosity thresholds for 5 sigma confirmation are provided for various string scales.

Abstract

Low-scale string models are phenomenological models in String Theory, in which the string scale M_s is of the order of TeV. String excited states which are characteristic modes in low-scale string models can be observed as resonances in dijet invariant mass distributions at the LHC. If a new heavy resonance is discovered at the LHC, it is important to investigate whether the resonance comes from low-scale string models. In this work, two analyses are performed: One is observing higher spin degeneracy of string excited states by an angular distribution analysis on the resonance, since the string resonance consists of several degenerate states with different spins. The other is observing second string excited states by a search for a second resonance in dijet invariant mass distributions, since second string excited states have characteristic masses of sqrt{2} times of masses of first string excited states. As the result of Monte Carlo simulations assuming the 14 TeV LHC, we give required luminosities for 5 sigma confirmation in each analysis, in case of M_s = 4.5, 4.75 and 5 TeV.