The LHC sensitivity to an anomalous Higgs coupling to the top quark in the Higgs-top associated production is analyzed. Thanks to the strong destructive interference in the t-channel for standard model couplings, this process can be very sensitive to both the magnitude and the sign of a nonstandard top-Higgs coupling. We analyze cross sections and the main irreducible backgrounds for the H → γγ decay channel. Sensitivities to an anomalous sign for the top Yukawa coupling are found to be large. In particular, at s√=14TeV , assuming a universal rescaling in the Yukawa sector, a parton-level analysis with realistic selection cuts gives a signal-to-background ratio S/B ~ 5, for −1.5≲Yt/YSMt≲0 . A number of events S ≃ 10 (with corresponding significances ~ 3 σ) are expected for 60 fb−1, to be compared with the standard-model expectation S ~ 0.3.
