2023/11/21 by Bin Yan, Christopher Lee, Yan, Bin +1 · 1 citation
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2311.12556
openalex publication_date 2023/11/21 · openalex created_date 2023/11/23 · openalex updated_date 2026/08/01
We propose to utilize angularity distributions in Higgs boson decay to probe light quark Yukawa couplings at e+e- colliders. Angularities τa are a class of 2-jet event shapes with variable and tunable sensitivity to the distribution of radiation in hadronic jets in the final state. Using soft-collinear effective theory (SCET), we present a prediction of angularity distributions from Higgs decaying to quark and gluon states at e+e- colliders to \rm NNLL+O(αs) accuracy. Due to the different color structures in quark and gluon jets, the angularity distributions from H→ qq and H→ gg show different behaviors and can be used to constrain the light quark Yukawa couplings. We show that the upper limit of light quark Yukawa couplings could be probed to the level of ∼15% of the bottom quark Yukawa coupling in the Standard Model in a conservative analysis window far away from nonperturbative effects and other uncertainties; the limit can be pushed to \lesssim 7-9% with better control of the nonperturbative effects especially on gluon angularity distributions and/or with multiple angularities.