Strange quark as a probe for new physics in the Higgs sector

TL;DR

This paper introduces a new strange-quark jet tagging algorithm for the ILD detector at the ILC, applies it to Higgs to strange decay analysis, and evaluates potential improvements with a RICH system for future Higgs factories.

Contribution

It presents the first application of strange-tagging to Higgs decay analysis and explores RICH detector enhancements for better strange-quark identification.

Findings

Upper limit on Higgs-strange coupling modifier: 7.14 at 95% CL.

Strange-tagging enables Higgs to strange decay studies at future colliders.

Preliminary RICH study shows potential for improved particle discrimination.

Abstract

This paper describes a novel algorithm for tagging jets originating from the hadronisation of strange quarks (strange-tagging) with the future International Large Detector (ILD) at the International Linear Collider (ILC). It also presents the first application of such a strange-tagger to a Higgs to strange ($h \rightarrow s\bar{s}$) analysis with the $P(e^-,e^+) = (-80\%,+30\%)$ polarisation scenario, corresponding to 900 fb$^{-1}$ of the initial proposed 2000 fb$^{-1}$ of data which will be collected by ILD during its first 10 years of data taking at $\sqrt{s} = 250$ GeV. Upper limits on the Standard Model Higgs-strange coupling strength modifier, $\kappa_s$, are derived at the 95% confidence level to be 7.14. The paper includes as well a preliminary study of a Ring Imaging Cherenkov (RICH) system capable of discriminating between kaons and pions at high momenta (up to 25 GeV), and thus enhancing strange-tagging performance at future Higgs factory detectors.