Higgs Boson Decay to Light Jets at the LHC

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 $\mathrm{BR}(h\to jj)\le 4{\mathrm{BR}}^{SM}(h\to gg)$ at $95\%$ confidence level. A consistency fit also leads to an upper bound $\mathrm{BR}(h\to cc)<15{\mathrm{BR}}^{SM}(h\to cc)$ at $95\%$ confidence level. The estimated bound may be further strengthened by adopting multiple variable analyses, or adding other production channels.

Comments: 23 pages, 9 figures, 10 tables