Nuclear and Particle Physics Colloquium 85

(核与粒子物理学术报告会85)

Place:Mainbuilding 316, Beihang University

Time:9:30-11:00,October14, 2019

Title:Charge changing cross section measurements —a possible method to extract point-proton radii of radioactive isotopes

Speaker:Prof.T. Yamaguchi, Saitama University (Japan)

Abstract:

Interaction cross sections and reaction cross sections of radioactive isotopes have been a good tool to extract matter radii since 80’s. It is important to separate neutron radii and point-proton radii from matter radii and to extract neutron skin for the understanding of nuclear matter equation of state. However, for point-proton radii (charge radii), the isotope shift method has been only the established tool to date, because electron scattering on radioactive isotopes was impossible. To overcome this difficulty, charge-changing cross sections are investigated, because they are related to a probability of proton removal from nuclei and thus are expected to be sensitive to the proton distributions. Such studies have been successful for the light neutron-rich nuclei. However, for medium-heavy nuclei, experimental and theoretical developments are still needed. In this presentation, I will review current status of our studies and will show our challenge to solve the problem.

About Speaker: Prof. Dr. Yamaguchi is an expert in interaction and reaction cross section measurements. In around 2010, he attempted to extract proton radii of light nuclei from the charge-changing cross section measurements. Since then, charge-changing cross section measurements have been an important subject in worldwide nuclear physics facilities.He currently focuses on precision mass and lifetime measurements of cooled and stored exotic ions. Professor Yamaguchi is now the spokesperson for the ILIMA collaboration.