Higgs-Boson Paarproduktion am LHC

• Applicant: Professor Dr. Matthias Steinhauser
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 252237208

After the discovery of a Higgs boson-like particle at the Large Hadron Collider (LHC) at CERN it is of primary importance to investigate its properties. Among them is the Higgs boson self-coupling which is predicted by the Standard Model of particle physics. Even the proof of just the existence of a coupling between three Higgs bosons would be a tremendous success. The data which will becollected at the LHC in the coming years allow for the first time to access this part of the Standard Model.In the proposed project higher order corrections to the production cross section of a pair of Higgs bosons shall be computed. This process is sensitive to the triple-Higgs boson coupling and it is thus necessary to obtain as precise predictions as possible. One of the main tasks of the project is the computation of the total cross section up to next-to-next-to-leading order in QCD perturbation theory in the infinite top quark mass limit. This requires to consider virtual and real corrections to the leading order process which is induced by the effective coupling of Higgs bosons to gluons. In a first step we plan to compute the virtual corrections which enables us to obtain the next-to-next-to-leading order prediction in the so-called soft-virtual approximation where the real corrections are considered in the soft limit. We can cross check against results present in the literature in the infinite top quark mass limit, however, we can also compute effects due to a finite top quark mass and thus obtain insight in the importance of such correction terms.Once the total cross section is available it is planned to consider kinematical distributions to next-to-leading order accuracy. The differential cross section is only known to leading order. In general, radiative corrections affect kinematical distributions much less than the total cross section. However, the latter receives corrections of order 100% from next-to-leading order terms and thus we expect significant numerical effects also for the differential cross sections which influences the analyses aiming for the extraction of the triple-Higgs boson coupling.

• DFG Programme: Research Grants