L. Canton

An algebraic solution of the multichannel problem applied to low energy nucleon-nucleus scattering

This is a pre-print version published in Nuclear Physics A

Predicting Narrow States in the Spectrum of a Nucleus beyond the Proton Drip Line

Properties of particle-unstable nuclei lying beyond the proton drip line can be ascertained by considering the (usually known) properties of its mirror neutron-rich system. We have used a multichannel algebraic scattering theory to map the known properties of the neutron-14C system to those of the proton-14O one from which we deduce that the particle-unstable 15F will have a spectrum of two low-lying broad resonances of positive parity and, at higher excitation, three narrow negative-parity ones. A key feature is to use coupling to Pauli-hindered states in the target.

Role of the Pauli principle in collective-model coupled-channel calculations.

A multichannel algebraic scattering theory, to find solutions of coupled-channel scattering problems with interactions determined by collective models, has been structured to ensure that the Pauli principle is not violated. By tracking the results in the zero coupling limit, a correct interpretation of the subthreshold and resonant spectra of the compound system can be made. As an example, the neutron-12C system is studied defining properties of 13C to 10 MeV excitation. Accounting for the Pauli principle in collective coupled-channels models is crucial to the outcome.

The One pion exchange three nucleon force and the A(y) puzzle

We consider a new three-nucleon force generated by the exchange of one pion in the presence of a 2N correlation. The underlying irreducible diagram has been recently suggested by the authors as a possible candidate to explain the puzzle of the vector analyzing powers

Coupled-channel evaluations of cross sections for scattering involving particle-unstable resonances.

A_y

Constraints on the spectra of 17,19C

and

Comparison between two methods of solution of coupled equations for low-energy scattering

iT_{11}

A fast converging separable expansion for realistic nuclear potentials

for nucleon-deuteron scattering. Herein, we have calculated the elastic neutron-deuteron differential cross section,

Separable expansions for realistic multichannel scattering problems

A_y

Practical approximation scheme for the pion dynamics in the three-nucleon system

,