Study of $t\bar{t}H$ production with $H\to b\bar{b}$ at the HL-LHC

Abstract

A feasibility study for an experimental analysis searching for $t\bar{t}H(H\to b\bar{b})$ production at the LHC and its high luminosity phase is presented in this note. Unlike search strategies currently being used in experimental collaborations, the present analysis exploits jet substructure techniques and focuses on the reconstruction of boosted Higgs bosons, to obtain sensitivity to the signal in a simple cut-based analysis. The $t\bar{t}+$ jets background may be constrained in the proposed analysis through a control region with very small signal contamination. Using this analysis strategy, the $t\bar{t}H(H\to b\bar{b})$ process could be observed at the LHC, in the semi-leptonic channel alone, with a significance of $5.41\pm 0.12$ for $\mathcal{L}=300\text{mbox}{fb}^{-1}$. For the same integrated luminosity, in the High Luminosity LHC scenario with an upgraded detector, a significance of $6.13\pm 0.11$ may be obtained. The top Yukawa coupling could be measured with a 35\% uncertainty using $\mathcal{L}=300\text{mbox}{fb}^{-1}$ of LHC data and of 17\% at the HL-LHC scenario with $\mathcal{L}=3000\text{mbox}{fb}^{-1}$. In the same luminosity scenarios, the signal strength is equally expected to have a 18$\%$ and 5$\%$ uncertainty, respectively. Finally, it was found that re-clustered jets may be used without loss of efficiency.

Comments: 5 pages, 5 figures