Spectroscopy of 46Ar by the (t,p) two-neutron transfer reaction

TL;DR

This study investigates the structure of the neutron-rich nucleus 46Ar using a two-neutron transfer reaction, identifying excited states and comparing experimental data with theoretical models to enhance understanding of nuclear structure near N=28.

Contribution

It provides new experimental data on 46Ar's excited states and compares these results with advanced shell model and reaction calculations, offering insights into nuclear structure.

Findings

Identification of an excited 0+ state at 3695 keV.

Measured angular distributions match theoretical transfer models.

Results support shell model predictions for 46Ar.

Abstract

States in the $N=28$ nucleus $^{46}$Ar have been studied by a two-neutron transfer reaction at REX-ISOLDE (CERN). A beam of radioactive $^{44}$ at an energy of 2.16~AMeV and a tritium loaded titanium target were used to populate $^{46}$ by the t($^{44}$,p) two-neutron transfer reaction. Protons emitted from the target were identified in the T-REX silicon detector array. The excitation energies of states in $^{46}$ have been reconstructed from the measured angles and energies of recoil protons. Angular distributions for three final states were measured and based on the shape of the differential cross section an excited state at 3695~keV has been identified as $J^\pi = 0^+$. The angular differential cross section for the population of different states are compared to calculations using a reaction model employing both sequential and direct transfer of two neutrons. Results are compared to shell model calculations using state-of-the-art effective interactions.