Large extra dimensions and dijet production in $\gamma \gamma$ collisions

TL;DR

This paper investigates how large extra dimensions could affect dijet production in gamma-gamma collisions, showing that virtual Kaluza-Klein excitations significantly alter cross-sections and can probe string scales up to 6.4 TeV.

Contribution

It demonstrates that dijet production in gamma-gamma collisions is a sensitive method to detect large extra dimensions and sets new limits on the effective string scale.

Findings

Virtual spin-2 Kaluza-Klein excitations modify the dijet cross-section.

Effective string scale can be probed up to 6.4 TeV.

Polarized photons improve the sensitivity by about 20%.

Abstract

We have studied dijet production in $\gamma \gamma$ collisions with a view to probing the physics of large extra dimensions. The exchange of virtual spin-2 Kaluza-Klein excitations is found to modify the dijet cross-section substantially from its Standard Model value and allows the effective string scale to be probed to values between 2.5 and 6.4 TeV in the unpolarised case. In the case where the photons are polarised, the limits are seen to improve by roughly 20%. Dijet production in $\gamma \gamma$ collisions is thus shown to be a very effective probe of large extra dimensions.