Searching for anomalous top quark interactions with proton tagging and timing detectors at the LHC

We study the LHC sensitivity to new broad neutral resonances produced in two-photon fusion and decaying to a top quark pair, γγ → tt . This is probed in central exclusive tt production in proton-proton collisions, pp → pttp . We use the tagging of the intact protons by PPS (CMS) and AFP (ATLAS) and consider the semi-leptonic tt channel. The sensitivity is also mapped onto a set of dimension-8 γγ tt operators in the large mass limit. Using the kinematical correlations between the intact protons and the reconstructed tt system, we obtain a sensitivity to the couplings of the dimension-8 operators of 1 . 4 10 − 11 GeV − 4 at 95