Searches for Higgs boson to charm-anticharm quark pairs at the Large Hadron Collider (LHC), are still too imprecise to precisely determine if the size of its branching fraction matches the Standard Model expectation. But Higgs boson decays to bottom-antibottom quark pairs, the dominant form of Standard Model Higgs boson decays, has a best fit value that is extremely close to the Standard Model predicted value and an uncertainty of roughly ± 50%.
This study breaks out decay detections by different kinds of Higgs boson production methods, which, aside from serving as an internal consistency check of the robustness of the Standard Model's understanding of the Higgs boson, is of only technical interest.
A search for Standard Model (SM) Higgs bosons produced via vector-boson fusion at the Large Hadron Collider and decaying into a charm quark-antiquark pair (H→cc¯) is presented. The datasets used correspond to integrated luminosities of 37.5 fb^−1 and 51.5 fb^−1 and were collected by the ATLAS detector from proton-proton collisions at s√=13 and 13.6 TeV, respectively.
The observed (expected) upper limit on the H→cc¯ production cross-section times branching ratio is 41 (28) times the SM prediction at 95% confidence level. Combining this search with the previous H→cc¯ search in associated production with a W or Z boson yields an observed (expected) limit on the Higgs-charm Yukawa coupling modifier of |Îșc| < 4.7 (3.9).
Higgs bosons decaying into a bottom quark-antiquark pair (H→bb¯) are measured simultaneously using the 51.5 fb^−1 dataset at s√=13.6 TeV, with an observed signal strength of 0.97+0.57−0.50 relative to the SM expectation. When combined with previous H→bb¯ results at 13 TeV, the observed (expected) significance reaches 3.2 (3.6) standard deviations, providing evidence for H→bb¯ events from vector-boson fusion.
ATLAS Collaboration, "Search for H→cc¯ and measurement of H→bb¯ in vector-boson fusion production with the ATLAS Detector" arXiv:2511.21911 (November 26, 2025).
The latest measurement of the top quark mass by the ATLAS Collaboration at the LHS is on the low end, but not terribly precise.
The top-quark mass is measured to be m(top) = 172.17 ± 0.80(stat) ± 0.81(syst) ± 1.07(recoil) GeV, with a total uncertainty of 1.56 GeV. The third uncertainty arises from changing the dipole parton shower gluon-recoil scheme used in top-quark decays.