Speaker
Dr
Bin Yan
(IHEP)
Description
We propose to utilize angularity distributions in Higgs boson decay to probe light quark Yukawa couplings at $e^+e^-$ colliders. Angularities $\tau_a$ 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 ${\rm NNLL}+\mathcal{O}(\alpha_s)$ accuracy. Due to the different color structures in quark and gluon jets, the angularity distributions from $H\to q\bar{q}$ and $H\to gg$ 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 up to $15\sim 22\%$ level of the bottom quark Yukawa coupling in the Standard Model.
Primary author
Dr
Bin Yan
(IHEP)
