Speaker
Description
A search for the Standard Model (SM) Higgs boson decaying to a charm quark-antiquark pair (𝐻 →ccbar) and a bottom quark-antiquark pair (𝐻 →bbar) via vector boson fusion (VBF) production is presented. For the 𝐻 →ccbar search, the analysis uses proton–proton collision data collected by the ATLAS detector at two centre-of-mass energies:37.5 fb−1 at√𝑠=13 TeV from 2018, and 51.9 fb−1 at √𝑠 =13.6 TeV from 2022 and 2023, corresponding to a total integrated luminosity of 89.4 fb−1. The observed (expected) upper limit on the VBF,𝐻 →ccbar production cross-section times branching ratio is 41.4 (28.8) at the 95% confidence level (CL). The Higgs boson decay to a bottom quark-antiquark pair (𝐻 →bbar) is simultaneously measured using the 51.9 fb−1 of proton-proton collision data at √𝑠 = 13.6 TeV collected during 2022 and 2023, cprresponding to Run-3 data-taking period. The Observed (expected) VBF,𝐻 →bbar event rate relative to the SM expectation is 0.96 (-0.31,
+0.31). When combined with the previous search for 𝐻 →ccbar via associated production with a W or Z boson, the observed (expected) 95% CL interval on the Higgs-charm Yukawa coupling modifier, kappaC, is|kappaC|<𝑋(𝑌), representing the most stringent constraint to data from ATLAS data. In addition, this result is combined with the previous ATLAS measurement of VBF,𝐻 →bbar, leading to the first evidence of VBF production with 𝐻 →bbar, with observed (expected) significances of 3.3 (3.4) standard deviations.
