Light quark Yukawa couplings from Higgs kinematics

TL;DR

This paper demonstrates that Higgs production kinematic distributions, specifically $p_T$ and rapidity, can be used to probe light quark Yukawa couplings, potentially revealing deviations from Standard Model predictions.

Contribution

It introduces a method to constrain light quark Yukawa couplings using Higgs kinematic distributions, providing competitive bounds and prospects for future measurements.

Findings

Normalized $p_T$ distribution is sensitive to light quark Yukawas.

Current ATLAS data can set bounds on light quark Yukawas.

Future LHC data can test flavor non-universality in Yukawa couplings.

Abstract

We show that the normalized Higgs production $p_T$ and $y_h$ distributions are sensitive probes of Higgs couplings to light quarks. For up and/or down quark Yukawa couplings comparable to the SM $b$ quark Yukawa the $\bar u u$ or $\bar d d$ fusion production of the Higgs could lead to appreciable softer $p_T$ distribution than in the SM. The rapidity distribution, on the other hand, becomes more forward. We find that, owing partially to a downward fluctuation, one can derive competitive bounds on the two couplings using ATLAS measurements of normalized $p_T$ distribution at 8\,TeV. With 300 fb${}^{-1}$ at 13\,TeV LHC one could establish flavor non-universality of the Yukawa couplings in the down sector.