Seminar:- Gamow-Teller Transitions: the most common weak process in the Universe
Stars shine with the energy caused by strong-interaction processes in nuclei. However, a careful observation suggests that they are usually controlled by weak-interaction processes. Gamow-Teller (GT) transitions in nuclei are the most common nuclear weak process in the Universe and they are called “allowed transitions” in β decay. They also play important roles in neutrino-induced reactions, e.g., in Supernovae.
Studying GT transitions can contribute a lot for the understanding of nuclear structure as well as nuclear interactions. Note that nuclei consist of two kinds of fermions, i.e., protons and neutrons having a spin of 1/2. Therefore, GT transitions caused by the simple “spin-isospin (δτ) operator” are good probes to reveal the critical properties of nuclei.
GT excitations are studied by β decays and charge-exchange (CE) reactions. Although β decays can provide the absolute GT transition strengths, they can only access those states situated lower than the decay Q-values. In contrast, (3He, t) CE reactions can study GT excitations up to high excitation energies. Therefore, β decay and CE reactions, caused by the weak and strong interactions, respectively, are complementary tools for the study of GT responses of nuclei.
時間：2016.04.22(五) 16:30
地點：香港大學 莊月明物理樓 522室
講者：Prof. Yoshitaka FUJITA (Research Center of Nuclear Physics & Department of Physics, Osaka University)
語言：英語
免費會議，歡迎公眾參加
【訊息由張詠倫提供】
此活動由香港大學物理學系主辦。
