Non-perturbative matrix elements for B-mixing and Lifetimes (C1c*)

• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 396021762

The project aims at the theoretical description of lifetime and mixing observables of B- mesons by calculating matrix elements of specific four-quark operators of mass dimension six and seven. To achieve this, we are going to pursue two different approaches. On the one hand, sum rules will be calculated at the three-loop level within the framework of the heavy-quark effective theory (HQET). In the second approach, we will establish a re-normalisation scheme for the relevant operators based on the gradient-flow formalism. The perturbative matching coefficients to the MSbar scheme will be calculated through next-to-next-to-leading order in the strong coupling, while the non-perturbative matrix elements will be determined on the lattice from available gauge configurations.

• DFG Programme: CRC/Transregios
• Subproject of: TRR 257: P3H: Particle Physics Phenomenology after the Higgs Discovery
• Applicant Institution: Karlsruher Institut für Technologie
• Project Heads: Professor Dr. Robert Harlander; Professor Dr. Alexander Lenz; Professor Dr. Ulrich Nierste