Automation of electroweak NLO corrections for physics beyond the Standard Model

• Applicant: Professor Dr. Ansgar Denner
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2014 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 265915222

With the discovery of the Higgs particle at the LHC the particle content of the Standard Model has been established. On the other hand, no convincing evidence for physics beyond the SM has emerged so far.Besides direct searches at the LHC, a key for the discovery of new physics are precision investigations ofstandard processes. On the theoretical side these require accurate predictions including higher-order perturbative corrections of the strong and electroweak interaction. As these are needed for many different processes and in various theories, automated tools are highly desirable. Such tools exist for the calculation of corrections of the strong interaction but not yet for the electroweak interaction.The central goal of this project is the development of a tool for the automated calculation of NLO corrections in general relativistic quantum field theories such as the Standard Model or extensions thereof. The input should consist of the underlying theory, in form of a set of Feynman rules or equivalently the corresponding Lagrangian, and the external particles of a given scattering or decay process. The output shall consist of the corresponding leading-order (tree-level) and next-to-leading-order (one-loop) amplitudes, which can be directly used for the calculation of physical predictions in Monte Carlo programs. The tool shall automatically include all relevant contributions, such as loop diagrams, counter terms and rational terms. Moreover it shall allow to calculate corrections in the leading-pole approximation, where only the leading terms in an expansion about intermediate resonances are taken into account. Thus, precise predictions can be obtained also for complicated processes for which complete calculations are presently not feasible.

• DFG Programme: Research Grants