Events

February 1, 2016 at 10:15 pm

INPP Seminar | Perturbative and Nonperturbative Coulomb Effects in Pionless EFT, Feb. 9

The Institute of Nuclear and Particle Physics (INPP) presents Sebastian Koenig, of The Ohio State University, presenting Perturbative and Nonperturbative Coulomb Effects in Pionless EFT,” on Thursday, Feb. 9, at at 4 p.m. in Edwards Accelerator Lab, Roger W. Finlay Conference Room.

Abstract:  At low energies, nuclear physics can be reduced to nonrelativistic nucleons with contact interactions. This so-called “pionless effective field theory (pionless EFT)” provides an elegant and rigorous approach to the few-nucleon problem, based on universal features that occur in other fields as well. It is possible to treat bound states, scattering, and reactions involving external currents in a single framework with controlled uncertainty estimates. The inclusion of long-range forces like Coulomb interaction, however, is a notoriously difficult subject because such effects become very strong exactly where the EFT is supposed to work best, thus providing a challenge for a consistent power counting in the scattering regime. For few-nucleon bound states, Coulomb contributions are generally expected to be small perturbation, but it turns out the understanding the interplay of short- and long-range forces is important for proper renormalization of the theory. In this talk, I will present some recent developments along these lines, focusing in particular on p-d scattering at very low energies and a new evaluation of the Triton—3He binding energy splitting that proposes a new perturbative expansion for the pionless theory.

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