Jul 6 – 13, 2022
Bologna, Italy
Europe/Rome timezone

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

Jul 8, 2022, 6:00 PM
Room 5 (Avorio)

Room 5 (Avorio)

Parallel Talk Higgs Physics Higgs Physics


Valentina Maria Martina Cairo (CERN)


One of the most interesting yet-to-be answered questions in Particle Physics is the nature of the Higgs Yukawa couplings and their universality. Key information in our understanding of this question arises from studying the coupling of the Higgs boson to second generation quarks. Some puzzles in the flavor sector and potential additional sources of CP violation could also have their origins in an extended Higgs sector.
Rare Higgs decay modes to charm or strange quarks are very challenging or nearly impossible to detect with the current experiments at the Large Hadron Collider, where the large multi-jet backgrounds inhibits the study of light quark couplings with inclusive H->qqbar decays. Future e+e- machines are thus the perfect avenue to pursue this research.
Studies were initiated in the context of Snowmass2021 (https://arxiv.org/abs/2203.07535) with particular emphasis on the Higgs coupling to strange quarks and the related flavour tagging challenges.

This gave light to the development of a novel algorithm for tagging jets originating from the hadronisation of strange quarks (strange-tagging) and the first application of such a strange-tagger to a direct Higgs to strange (h->ssbar) analysis.

The analysis is performed with the future International Large Detector (ILD) at the International Linear Collider (ILC), but it is easily applicable to other Higgs factories. The $P(e^-,e^+) = (-80\%,+30\%)$ polarisation scenario was used for this preliminary result, corresponding to \unit[900]{\ifb} of the initial proposed \unit[2000]{\ifb} of data which will be collected by ILD during its first 10~years of data taking at \sqrts = \unit[250]{GeV}. The study includes as well a preliminary investigation of a Ring Imaging Cerenkov system (RICH) capable of maximising strange-tagging performance in future Higgs factory detectors.

In-person participation No

Primary authors

Kiyotomo Kawagoe (Kyushu University) Matthew Basso (University of Toronto) Valentina Maria Martina Cairo (CERN)

Presentation materials