INPAC-Seminar 142

Title:  Probing Neutron-Proton Correlations using Direct Reactions

Speaker:  Prof. Jenny Lee, RIKEN Nishina Center, the University of Hong Kong

Location:  Lecture Hall/INPAC

Time: 12:30-14:00, Thursday, March 13, 2014

Abstract:

Obtaining information on neutron-proton correlations in nuclei is one of the primary goals of fundamental physics. The interest in neutron-proton correlations stems not only from the necessity of full understanding of the isospin T=0 part of nuclear interaction and the interplay between T=0 and T=1 nucleon pairs, but also from the considerable impact on nuclear structure and nucleosynthesis as well as the nature of astrophysical objects, such as neutron stars.

Two-nucleon removal reactions offer a powerful tool to investigate nucleon-nucleon (NN) correlations. A well-documented case is high-energy electron-induced (e,e’pN) pair-removal measurements on 12C, suggesting that neutron-proton pairs are about 20 times more prevalent than like-nucleon pairs attributed to the short-range correlations in nuclei. Using different reaction mechanisms, the probe has sensitivity to different parts of the nuclear wave function, from which one can quantify the roles of short-range, medium-range tensor, and longer range components of NN correlations. To expand the scope and understand the behavior of neutron-proton correlations as a function of pair-relative-momentum, we have performed / proposed experiments with different reaction probes at different facilities:

1. RCNP, Osaka University (Japan): Study of pairing correlations using low-energy transfer reactions of sd-shell N=Z nuclei (completed in 2012)
2. RIBF, RIKEN Nishina Center (Japan): Study of 2N correlations using heavy-ion induced knockout reactions of 12C at intermediate energies (completed in 2013)
3. CSR-IMP, Lanzhou (China): Study of short range correlation in nuclei with high-energy proton beam (proposed)
In this talk, I will present these experiments and discuss about the preliminary results.