# Constraints on the Higgs boson anomalous FCNC interactions with light quarks

## TL;DR

This paper investigates constraints on Higgs boson flavor-changing neutral current interactions with light quarks using effective field theory, analyzing current LHC data and projecting sensitivities for future colliders like HL-LHC and FCC-hh.

## Contribution

It provides new upper limits on Higgs FCNC branching fractions with light quarks based on detailed simulations and projections for future collider sensitivities.

## Key findings

- Upper limits on $H o bar{s}$ and $H o bar{d}$ from LHC data.
- Projected sensitivity of FCC-hh to FCNC interactions at 95% CL.
- Realistic detector simulation and analysis reproduction for Higgs decay channels.

## Abstract

We consider the Higgs boson anomalous FCNC interactions with $u$, $c$, $d$, $s$ and $b$ quarks using the effective field theory framework. Constraints on anomalous couplings are derived from experimental results on Higgs boson production with subsequent decay into $b \bar{b}$ pair at LHC with $\sqrt{s} = 13 $~TeV. Upper limits on the branching fractions of $H \to b\bar{s}$ and $H \to b\bar{d}$ are set by performing a realistic detector simulation and accurately reproducing analysis selections of the CMS Higgs boson measurement in the four-lepton final state at $\sqrt{s} = 13$ TeV. The searches are projected into operation conditions of HL-LHC. Sensitivity at FCC-hh to anomalous FCNC interactions is studied based on Higgs boson production with $H \rightarrow \gamma \gamma$ decay channel. It is shown that at FCC-hh machine one can expect to set the upper limits of the order of $10^{-2}$ at $95\%$ CL for $\mathcal{B}(H \rightarrow b\bar{s})$ and $\mathcal{B}(H \rightarrow b\bar{d})$.