Probing new physics through ultimate precision determination of the Higgs boson properties and detector development towards future experiments

The discovery of the Higgs boson in 2012 is one of the most important milestones in particle physics. Today, our dataset from the ATLAS detector is equivalent to 11M Higgs bosons. This large statistics of dataset allows us to use the Higgs boson as a 'probe' to search for new physics beyond the standard model (BSM) through precise determination of various properties of the Higgs boson such as mass, branching ratios etc.; I will be particularly focusing on differential cross-section measurements targeting the extremely high pT regime.

The exploration of the Higgs sector will not end at LHC. Rather, it will become more important at High Luminosity (HL) LHC, where we expect 10x larger statistics than what we have today. Towards operation of HL-LHC, the new fully-silicon inner tracking system (ITk) needs to be ready by mid. 2027. The ATLAS Japan group is responsible for constructing 2,800 pixel modules and 6,350 strip sensors. I will introduce my work in this challenging project, including the recent ramp-up of the ITk system test activities at CERN. Furthermore, future experiments such as the Higgs factory and, ultimately, the 100-TeV hadron collider will provide us with a full picture of the Higgs sector, where we anticipate harsh experimental environments in terms of event rates as well as radiation damage. I will spend a few minutes to briefly introduce my recent work on the investigation of gallium-nitride semiconductors for future tracking devices.