Precise predictions for vector-boson scattering at hadron colliders

• Applicant: Professor Dr. Ansgar Denner
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 322921231

With the discovery of the Higgs boson at the Large Hadron Collider (LHC) in 2012, the last missing particle of the standard model of elementary particle physics has been established. Via the mechanism of electroweak symmetry breaking, the Higgs boson provides the observed masses for the particles of the standard model and guarantees at the same time the unitarity of the theory. The scattering of electroweak vector bosons is the most important key process to study this mechanism and can be measured at the LHC with high precision. Since the deviations from the standard model might be small, precise theoretical predictions are required for a thorough analysis of these processes. The central goal of this research proposal is the calculation of next-to-leading-order corrections to vector-boson scattering in the standard model. Thereby also corrections of the electroweak interaction will be determined for the first time for this class of processes in a realistic setup. We have found that electroweak corrections change the predictions for vector-boson scattering at the LHC by several tens of per cent and are thus crucial for the correct description of the experimental data. We therefore plan to calculate these corrections for all relevant vector-boson scattering processes at the LHC. We will not only consider the genuine matrix elements for vector-boson scattering but include the complete set of tree-level and one-loop contributions in the full standard model that contribute to the relevant six-particle final states. In order to evaluate perturbative corrections to these complicated processes, appropriate methods have to be developed. Besides higher-order corrections in the standard model, we will also take into account effects from beyond thestandard model via appropriate effective couplings. If new physics pointing to specific extensions of the standard model should be observed at the LHC in the near future, our calculations can be adapted to the corresponding models.

• DFG Programme: Research Grants