Coulomb dynamical polarization potential for  neutron-rich nuclei

Project title:Coulomb dynamical polarization potential for neutron-rich nuclei

Dates and places of research: Heavy ion Laboratory, University of Warsaw, Poland, 2020-2022.

Sources of funding: The Polish National Agency for Academic Exchange (NAWA)

Collaboration: Prof. K. Rusek and Prof. N. Keeley

Output of the project: 

A. Articles:

B. Presentations:

Description

Coulomb dissociation of neutron-rich light and medium nuclei 

A new method for calculating the Coulomb breakup of unstable neutron-rich isotopes at high energies is presented. The calculations employ the eikonal approximation and use a new Coulomb dynamical polarization potential, calculated by solving the Schrödinger equation for the entire motion of the exotic projectile as a two-body cluster structure using the adiabatic approximation and incorporating excitations to the continuum. Calculations for some exotic isotopes are compared with Coulomb dissociation cross section data and found to be in good agreement.

Comparison of Coulomb breakup effects on the elastic scattering of 6He and 8He using a Coulomb dipole polarization potential

In this work, the new expression for the Coulomb dipole polarization potential (CDPP) is applied to different cluster structures of 6He and 8He. The CDPPs are used to compare the effect of breakup coupling on the elastic scattering of these projectiles from a 208Pb target at incident energies of 16 and 14 MeV, below the Coulomb barrier. None of the cluster structures investigated for 8He gives a significant CDPP, supporting previous inferences that breakup coupling is much less important for 8He than for 6He at energies close to the Coulomb barrier, despite the significantly larger absorption observed in the measured 8He elastic scattering at 16 MeV compared to that for 6He. Coupled reaction channels calculations of the 1n stripping reaction indicate a much enhanced role for this reaction in the elastic scattering of 8He compared to 6He, alone sufficient to account for the observed significant deviation from Rutherford scattering for 8He + 208Pb elastic scattering even at this sub-barrier energy.

Coulomb dynamical polarization potential and the electric dipole polarizability for weakly bound and neutron-rich light nuclei

In this work, we present a method to determine the dipole polarizability of light exotic nuclei with a two-body deuteronlike cluster structure. Using the adiabatic approximation, we solve the Schrödinger equation for the internal motion of the exotic projectile incident on a heavy target nucleus and express the resulting Coulomb dynamical polarization potential (CDPP) in terms of regular and irregular Coulomb functions. We then obtain a new expression for the dipole polarizability (α0) by equating the real part of this CDPP to the classical expression for the polarization potential. The α0 values for many weakly bound light nuclei are calculated and where values are available were found to be in good agreement with those obtained in previous studies using various other methods.