Speaker
Description
The difference in proton-proton and neutron-neutron scattering lengths contributes to understanding the charge-symmetry breaking of nuclear forces, yet the Coulomb-free proton-proton scattering length (app) cannot be measured directly and relies heavily on numerous and distinct theoretical techniques to remove the Coulomb contribution. We determined the Coulomb-free p-p scattering length from the half-off-the-energy-shell p-p scattering cross section measured at center-of-mass energies below 1 MeV using the quasi-free p + d→p + p + n reaction. The resulting difference in proton-proton and neutron-neutron scattering lengths suggests a lower charge symmetry breaking of nuclear forces than predicted so far. A model based on universality concepts has been developed to interpret this result in the framework of the short-range physics. Results will be presented and discussed.
