Session H18: Higgs Measurements at the LHC and Future Colliders

Live

The precision measurements of the properties of the Higgs boson are among the principal goals of the LHC Run-2 program. This talk reports on the measurements of the fiducial and differential Higgs boson production cross section via Vector Boson Fusion with an electron, a muon, and two energetic neutrinos from the decay of W bosons, along with the presence of two energetic jets in the final states. The analysis uses $pp$ collision data at a center-of-mass energy of 13 TeV collected with the ATLAS detector between 2015 and 2018 corresponding to an integrated luminosity of 139 fb$^{-1}$. The optimizations of the selection criteria and the signal extraction methods will be discussed in detail, in particular the use of machine learning techniques for performing a multidimensional fit for extracting the signal and normalizing the simulated backgrounds to data.   

Live

Precision measurement of Higgs boson production and decay rates is one of the most important tasks after the Higgs boson discovery at the LHC in 2012. In this presentation, I will report inclusive cross section measurements for the dominant Higgs boson production modes, as well as Simplified Template Cross Sections, in the di-photon decay channel using 139 $fb^{-1}$ of $pp$ collision data collected by the ATLAS experiment during 2015-2018. I will also discuss how the measurements constrain the Higgs boson couplings to other particles in the Standard Model.   

Live

The FCC-ee, a lepton collider with center-of-mass collision energies between 90 and 365 GeV, is proposed to address key open questions of modern physics. The precision instrument is designed for the in-depth exploration of nature at the smallest scales, optimized to study the Z, W, Higgs and top particles with high precision. FCC-ee offers unprecedented sensitivity to study the Higgs boson. The focus of the presentation is on recent Higgs physics results.   

Not Participating

As a proposed Higgs factory, the cornerstone of the FCC-ee physics program is the exploration of the Higgs boson at center-of-mass energies of 240 to 365 GeV. A direct and model-independent measurement of its coupling to the Z boson through the study of the Z boson recoil mass spectrum. The recoil mass analysis strategy can be deployed to search for non-SM Higgs boson decays such as Higgs boson to invisible decays or more exotic signatures. The mass spectrum recoiling the Z boson can also be explored in searches for new scalars with coupling to the Z boson. The extremely large FCC-ee data samples especially at lower center-of-mass energy offer excellent sensitivity.   

Not Participating

Searches for the charged lepton flavor violating processes have a long history, and their importance stems from their potential to probe physics higher than the TeV scale. Some beyond the standard model theories allow for lepton flavor violating decays of the Higgs boson, and observing such decays will be a clear sign of new physics. A search for the Higgs boson decaying into $\mu\tau$ and $e\tau$ final states has been performed using the full Run 2 data collected at the CMS experiment. These search results are expressed in terms of the upper limits on the branching fraction of the Higgs boson decaying into these final states. They are correspondingly translated into limits on the Yukawa couplings.   

Live

We investigate the two dominant off-shell production mechanisms of the Higgs boson in gluon fusion and weak vector boson fusion with a decay to two Z bosons. Several Monte Carlo techniques are compared and discussed. Effects of Effective Field Theory (EFT) operators on kinematic distributions are investigated. Prospects for the measurement of Higgs boson properties with the LHC and HL-LHC are presented.