Date:
Tue, 05/11/201312:00-13:30
Location:
Racah Institute of Physics, Moadon (Bitan 9)
"Weak constraints on the strong three-nucleon forces within Chiral-EFT":
Chiral-EFT is an effective field theory approach to describe nuclear phenomena. In this approach nucleons and pions are the relevant degrees of freedom and one writes the most general Lagrangian invariant under the symmetries of QCD. Chiral-EFT further prescribes a scheme for ordering the terms in the Lagrangian according to their relative importance, thus allowing the precision of the calculation to be controlled. Three-body forces first appear at next-to-next-to-leading order (N2LO), with two unconstrained coefficients called low-energy constants (LECs). These coefficients can be constrained by the triton’s binding energy and beta decay. We will show the benefits of using a weak constraint as opposed to a strong constraint, and as a first test case we present predictions, without free parameters, for the binding energy of 4He, and provide a theoretical error estimate.
Chiral-EFT is an effective field theory approach to describe nuclear phenomena. In this approach nucleons and pions are the relevant degrees of freedom and one writes the most general Lagrangian invariant under the symmetries of QCD. Chiral-EFT further prescribes a scheme for ordering the terms in the Lagrangian according to their relative importance, thus allowing the precision of the calculation to be controlled. Three-body forces first appear at next-to-next-to-leading order (N2LO), with two unconstrained coefficients called low-energy constants (LECs). These coefficients can be constrained by the triton’s binding energy and beta decay. We will show the benefits of using a weak constraint as opposed to a strong constraint, and as a first test case we present predictions, without free parameters, for the binding energy of 4He, and provide a theoretical error estimate.