## Problems in Theoretical Nuclear Physics, Cortona, Italy 18-20 October

This project aims to undertake the algorithmic and software development needed to enable the nuclear physics lattice QCD community to make optimal use of forthcoming leadership-class and dedicated hardware to address key problems in nuclear physics.

Nucleons are composite particles made up of quarks and gluons. There exists to date partial answers on how the quarks are distributed and move within the nucleon and the 2004 Nobel Prize in Physics was awarded for the discovery of asymptotic freedom within the context of perturbative Quantum Chromo-Dynamics (QCD). However, QCD is unsolved in the confinement regime where the quark coupling strength is too large to permit perturbative methods to be used. One of the central problems in nuclear physics remains the connection of the observed properties of the hadrons to the underlying theoretical framework of QCD. The solution requires advances both in theory and experiment. In a few specific cases, where chiral coefficients are well known, recent advances in lattice QCD, in combination with chiral perturbation theory, have allowed one to extrapolate full lattice simulations to physical quark masses; thus enabling a direct comparison with experimental observables. The objectives are:

## An R-matrix package for coupled-channel problems in nuclear physics

This group is engaged in a program of research which uses the spin property of elementary particles to study fundamentals problems in nuclear physics. These experiments are carried out at the Jefferson National Laboratory. Much of our research program involves measuring the small effects that result from parity violation, which gives the Universe a fundamental distinction between “left” and “right”.