A clear Dark Matter gamma ray line generated by the Green-Schwarz mechanism

TL;DR

This paper explores a $U_X(1)$ extension of the Standard Model with a Green-Schwarz mechanism, predicting a gamma-ray line from dark matter that could be detectable by FERMI/GLAST, offering a new probe for low-energy string scales.

Contribution

It introduces a novel anomaly-free $U_X(1)$ model with a dark gauge field producing a gamma-ray line, testable by gamma-ray telescopes, linking string theory to observable astrophysical signals.

Findings

A 2 TeV BSM scale is testable by FERMI/GLAST after 5 years.

The model predicts a distinct gamma-ray line signature.

The Green-Schwarz mechanism ensures anomaly cancellation in the model.

Abstract

We study the phenomenology of a $U_X(1)$ extension of the Standard Model where the SM particles are not charged under the new abelian group. The Green-Schwarz mechanism insures that the model is anomaly free. The erstwhile invisible dark gauge field $X$, even if produced with difficulty at the LHC has however a clear signature in gamma-ray telescopes. We investigate what BSM scale (which can be interpreted as a low-energy string scale) would be reachable by the FERMI/GLAST telescope after 5 years of running and show that a 2 TeV scale can be testable, which is highly competitive with the LHC.