Journal of High Energy Physics (Aug 2022)
Searching for anomalous top quark interactions with proton tagging and timing detectors at the LHC
Abstract
Abstract We study the LHC sensitivity to new broad neutral resonances produced in two-photon fusion and decaying to a top quark pair, γγ → t t ¯ $$ t\overline{t} $$ . This is probed in central exclusive t t ¯ $$ t\overline{t} $$ production in proton-proton collisions, pp → pt t ¯ p $$ pt\overline{t}p $$ . We use the tagging of the intact protons by PPS (CMS) and AFP (ATLAS) and consider the semi-leptonic t t ¯ $$ t\overline{t} $$ channel. The sensitivity is also mapped onto a set of dimension-8 γγt t ¯ $$ \gamma \gamma t\overline{t} $$ operators in the large mass limit. Using the kinematical correlations between the intact protons and the reconstructed t t ¯ $$ t\overline{t} $$ system, we obtain a sensitivity to the couplings of the dimension-8 operators of 1.4 10 −11 GeV −4 at 95% CL. The sensitivity to the anomalous couplings is significantly improved down to about 7 10 −12 GeV −4 if the proton time-of-flight is known with a precision of 20 ps in future measurements. The 95% CL sensitivity to broad neutral resonances reaches masses of order 1500 GeV when using timing information.
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