Higgs Boson Decay to Light Jets at the LHC

TL;DR

This paper investigates the potential to measure or constrain the Higgs boson's decay into light jets at the HL-LHC, focusing on the dominant $h o gg$ channel and estimating achievable bounds with high luminosity data.

Contribution

It provides the first detailed estimate of bounds on Higgs decay to light jets at the HL-LHC, including analysis strategies and potential improvements.

Findings

Expected 1σ significance for $h o gg$ at HL-LHC with 3000 fb$^{-1}$

Upper bound on $BR(h o jj)$ is approximately 4 times the SM prediction

Upper bound on $BR(h o cc)$ is less than 15 times the SM prediction

Abstract

We study the Higgs boson $(h)$ decay to two light jets at the 14 TeV High-Luminosity-LHC (HL-LHC), where a light jet ($j$) represents any non-flavor tagged jet from the observational point of view. The decay mode $h\to gg$ is chosen as the benchmark since it is the dominant channel in the Standard Model (SM), but the bound obtained is also applicable to the light quarks $(j=u,d,s)$. We estimate the achievable bounds on the decay branching fractions through the associated production $Vh\ (V=W^\pm,Z)$. Events of the Higgs boson decaying into heavy (tagged) or light (un-tagged) jets are correlatively analyzed. We find that with 3000 fb$^{-1}$ data at the HL-LHC, we should expect approximately $1\sigma$ statistical significance on the SM $Vh(gg)$ signal in this channel. This corresponds to a reachable upper bound ${\rm BR}(h\to jj) \leq 4~ {\rm BR}^{SM}(h\to gg)$ at $95\%$ confidence level. A consistency fit also leads to an upper bound ${\rm BR}(h\to cc) < 15~ {\rm BR}^{SM}(h\to cc)$ at $95\%$ confidence level. The estimated bound may be further strengthened by adopting multiple variable analyses, or adding other production channels.