Anomalous $U(1)$ Gauge Bosons as Light Dark Matter in String Theory

TL;DR

This paper explores how anomalous U(1) gauge bosons from string theory compactifications could serve as light dark matter candidates, potentially explaining experimental anomalies like the XENON1T excess.

Contribution

It demonstrates that anomalous U(1) gauge bosons in D-brane string models can be viable light dark matter candidates under current experimental constraints.

Findings

Anomalous U(1) gauge bosons can be light and weakly coupled.

These gauge bosons could explain the XENON1T excess.

They are consistent with current LHC bounds.

Abstract

Present experiments are sensitive to very weakly coupled extra gauge symmetries which motivates further investigation of their appearance in string theory compactifications and subsequent properties. We consider extensions of the standard model based on open strings ending on D-branes, with gauge bosons due to strings attached to stacks of D-branes and chiral matter due to strings stretching between intersecting D-branes. Assuming that the fundamental string mass scale saturates the current LHC limit and that the theory is weakly coupled, we show that (anomalous) $U(1)$ gauge bosons which propagate into the bulk are compelling light dark matter candidates. We comment on the possible relevance of the $U(1)$ gauge bosons, which are universal in intersecting D-brane models, to the observed $3\sigma$ excess in XENON1T.