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Universidad de Granada CAFPE

Seminar: Matching high-energy QFTs onto low-energy nonrenormalizable ones without higher dimension operators

Speaker: Roberto Pittau, UGR

Place: Seminario del Dpto Física Teórica y del Cosmos

Date: 26/11/2019

Time (24h): 16:00

Abstract:
We derive the conditions for matching high-energy renormalizable Quantum Field Theories onto low-energy nonrenormalizable ones by means of the FDR approach. Our procedure works order-by-order in the loop expansion and avoids the addition of higher dimensional interactions into the nonrenormalizable Lagrangian. To illustrate our strategy, we match the high-energy fermion-loop corrections computed in the complete electroweak theory onto the nonrenormalizable four-fermion Fermi model. As a result, the Fermi Lagrangian can be used without modifications to reproduce, at arbitrary loop orders and energies, the exact electroweak interactions between two massless fermion lines induced by one-fermion-loop resummed gauge boson propagators. To our knowledge, this is the first-ever example of nonrenormalizable model consistently made predictive at all loop orders for a given class of physical processes.