Charm-quark Yukawa coupling in [formula omitted] at LHC.

It is extremely challenging to probe the charm-quark Yukawa coupling at hadron colliders primarily due to the large Standard Model (SM) background (including h → b b ¯) and the lack of an effective trigger for the signal h → c c ¯. We examine the feasibility of probing this coupling at the LHC via a Higgs radiative decay h → c c ¯ γ. The existence of an additional photon in the final state may help for the signal identification and background suppression. Adopting a refined triggering strategy and utilizing basic machine learning, we find that a coupling limit of about 8 times the SM value may be reached with 2 σ sensitivity after the High Luminosity LHC (HL-LHC). Our result is comparable and complementary to other projections for direct and indirect probes of h → c c ¯ at the HL-LHC. Without a significant change in detector capabilities, there would be no significant improvement for this search from higher energy hadron colliders. [ABSTRACT FROM AUTHOR]