Structure of 16C from analyses of proton scattering data and the B(E2) problem

TL;DR

This paper investigates the structure of carbon-16 by analyzing proton scattering data and shell model calculations to resolve discrepancies in the measured B(E2) transition probability.

Contribution

It presents a large-scale shell model calculation of 16C and compares it with experimental data to clarify the B(E2) problem.

Findings

Shell model calculations yield B(E2) values consistent with experimental data.

Proton scattering data supports the shell model results.

Effective neutron charges are examined in the context of the data.

Abstract

The B(E2) value for the decay of the 2+_1 state in 16C to ground has been the subject of much discussion. Analyses assuming a simple model of two neutrons coupled to a 14C core of the available data, which extend over an order of magnitude,gives reasonable agreement but with an inclusion of a large effective charge for the neutrons. To assess this situation, a large scale (2+4)hw shell model calculation of 16C has been made from which the wave functions have been used to obtain the B(E2) value. As a check, comparison is made with available data on the spectrum of 16C and intermediate-energy elastic proton scattering.