Charm-quark Yukawa coupling in h→cc¯γ at LHC

• Main Authors: Tao Han, Benjamin Nachman, Xing Wang
• Format: Article
• Language: English
• Published: Elsevier 2019-06-01
• Series: Physics Letters B
• Online Access: http://www.sciencedirect.com/science/article/pii/S0370269319302643

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→bb¯) and the lack of an effective trigger for the signal h→cc¯. We examine the feasibility of probing this coupling at the LHC via a Higgs radiative decay h→cc¯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 2σ sensitivity after the High Luminosity LHC (HL-LHC). Our result is comparable and complementary to other projections for direct and indirect probes of h→cc¯ 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.