Strange Couplings to the Higgs

TL;DR

This paper investigates how the coupling of strange quarks to the 126 GeV Higgs-like particle affects its production and decay, using LHC data to constrain the strength of this coupling relative to the Standard Model.

Contribution

It provides the first quantitative upper limit on the strange quark coupling to the Higgs-like resonance based on diphoton decay observations.

Findings

Strange quark coupling can be at most ~50 times the SM expectation.

Enhanced strange coupling increases jet decay rates and suppresses non-jet decay modes.

Current data constrains strange coupling to the Higgs-like particle at 95% confidence level.

Abstract

We explored the coupling of strange quark to the state of mass close to 126 GeV recently observed by the ATLAS and CMS experiments at the LHC. An enhanced coupling relative to the expectations for a SM Higgs has the effect of increasing both the inclusive production cross section and the partial decay width into jets. For very large modifications, the latter dominates and the net rate into non-jet decay modes such as diphotons is suppressed, with the result that one can use observations of the diphoton decay mode to place an upper limit on the strange quark coupling. We find that the current observations of the diphoton decay mode imply that the coupling of the new resonance to strange quark can be at most ~ 50 times the SM expectation at the 95 % C.L., if one assumes at most a O(1) modification of the coupling to gluons.