Six years after its discovery the properties of the Higgs boson (spin, mass. couplings) are now well measured, and consistent with the prediction of the Standard Model (SM). But the shape of the Higgs potential itself is not completely known, and depends on the self-coupling of the Higgs boson. This self-coupling could be probed at the HL-LHC, the high-luminosity phase of the LHC starting in 2026, through the production of Higgs boson pairs.
The analyses as started already, and the latest measurements with the ATLAS detector will be presented, concentrating on searches for enhanced HH production in beyond-the-SM scenarios, such as resonant production via a new heavy scalar, or non-SM couplings to the Higgs boson, either of which would increase the HH cross section.
Prospective studies of the physics potential at the HL-LHC has just been submitted to the European Strategy for Particle Physics, where direct and indirect measurements of the Higgs boson self-coupling are performed. Those studies by the ATLAS, CMS and theorists communities will be presented, as well as comparisons to future accelerators.
Keywords: Higgs, ATLAS, LHC (Run 2-3), HL-LHC