Dark matter annihilation into gamma-ray line generated by anomalies

TL;DR

This paper explores a $U_X(1)$ extension of the Standard Model with anomaly cancellation via the Green-Schwarz mechanism, predicting gamma-ray signatures from dark matter annihilation detectable by FERMI/GLAST, potentially probing TeV-scale physics.

Contribution

It introduces a novel anomaly-free $U_X(1)$ model with unique gamma-ray signatures from dark matter, linking collider and astrophysical tests of TeV-scale physics.

Findings

FERMI/GLAST can test a 1 TeV BSM scale after 5 years.

Dark gauge field $X$ produces detectable gamma-ray lines.

Model is consistent with anomaly cancellation via Green-Schwarz mechanism.

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 1 TeV scale can be testable, which is highly competitive with the LHC.