Search for $\text{H}\to \text{b}\bar{\text{b}}$ in association with single top quarks as a test of Higgs couplings

TL;DR

This paper searches for Higgs boson production with a single top quark via the decay to b quarks, testing a model with an inverted top Yukawa coupling, and sets upper limits on its cross section using CMS data.

Contribution

It provides the first upper limits on the production of Higgs with a single top quark for the $y_t=-1$ coupling scenario using 2012 CMS data.

Findings

Upper limit on production cross section is 7.57 times the expected.

Excludes associated tHq production with $y_t=-1$-like characteristics below 1.77 pb.

Sensitivity of the analysis is 5.14 times the expected cross section.

Abstract

The associated production of Higgs boson and single top quark is of particular interest since it is senstive to the relative sign of the Higgs boson coupling to gauge bosons and the Yukawa coupling $y$ to fermions. The presented analysis is setting upper production limits on a model with $y_\text{t}=-1$, which has an enhanced cross section compared to the standard model expectation. For this it focusses on the Higgs boson decaying to a pair of b quarks and uses the full dataset of $pp$ collisions recorded with the CMS detector in 2012. It reports an upper limit on 7.57 times the expected cross section, with an expected sensitivity of 5.14. This translates into the exclusion of associated tHq production with $y_\text{t}=-1$-like characteristics with a cross section smaller than 1.77\,pb.