  We quantify the impact of gauge anomalies at the Large Hadron Collider by
studying the invariant mass distributions in Drell-Yan and in double prompt
photon, using an extension of the Standard Model characterized by an additional
anomalous U(1) derived from intersecting branes. The approach is rather general
and applies to any anomalous abelian gauge current. Anomalies are cancelled
using either the Wess-Zumino mechanism with suitable Peccei-Quinn-like
interactions and a Stueckelberg axion, or by the Green-Schwarz mechanism. We
compare predictions for the corresponding extra Z-prime to anomaly-free
realizations such as those involving U(1)_{B-L}. We identify the leading
anomalous corrections to both channels, which contribute at higher orders, and
compare them against the next-to-next-to-leading order (NNLO) QCD background.
Anomalous effects in these inclusive observables are found to be very small,
far below the percent level and below the size of the typical QCD corrections
quantified by NNLO K-factors.
