Nuclear and Particle Physics Colloquium 35
Place: Room 513, Old Main Building, Beihang University
Time: 15:00-16:30, March 6, 2017
Title: Evidence of enhanced matter radius of 3-alpha rotational state in
alpha + 12C inelastic scattering
Speaker: Prof. Makoto Ito，Kansai University, Japan
Alpha cluster structures are known to appear in excited states of light nuclear systems systematically. A typical example of the cluster states is the so called Hoyle state (02+) in 12C, which has the developed 3 alpha structure. Previous calculations of alpha cluster models predict the enhancement of the radius of the 02+ state by about 50 percent in comparison to the radius of the ground state, which is proportional to the mass number to the one third power. Recently, several authors try to get the evidence of the extended radius of the 02+ state in the 12C → 12C(02+) inelastic scattering but the relation of the enhanced 3 alpha radius and its excitation through the 12C inelastic scattering still remains unclear. In this seminar, I will summary the previous studies relevant to the 12C → 12C(02+) inelastic scattering and point out the problem in the relation of the radius of 02+ and the respective inelastic scattering. I focus on the 22+ state, which corresponds to the rotational state of the Hoyle 02+ state, and propose a new viewpoint to speculate the lower limit of the radius of this Hoyle rotational state. The students, who have an elementary skill of scattering theory in quantum mechanics, can easily understand the contents of this seminar. In particular, the knowledge of diffraction scattering of light, Born approximation and Fourier transformations are useful to understand the essential point in this seminar.
About the Speaker:
Makoto(誠) Ito(伊藤)，男，日本国関西大学教授，2000年博士 日本国大阪市立大学。He has worked in the field of nuclear structure and reaction physics. A unified model from cluster structure to reaction problems which he proposed has been mainly applied to Be isotopes.