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Seeing is Believing: Quantum Selection Rules and Uncertainty Principle “SEEN” by the Study of Gamow-Teller Transitions


Speaker:Prof. Yoshitaka FUJITA
Affiliation:Research Center for Nuclear Physics & Department of Physics, Osaka University
Date:November 22, 2017 (Wednesday)
Time:3:30 p.m.
Venue:Room 522, 5/F, Chong Yuet Ming Physics Building, HKU

Abstract
 

NUCLEI can be defined as “Quantum Finite Many-body System consisting of two Fermions,” i.e., PROTON and NEUTRON. Note that they have SPIN. In addition, owing to the similarity of proton and neutron in terms of mass as well as nuclear forces working among them, they are identified by the Tz= -1/2 and +1/2 components of NUCLEON with the ISOSPIN quantum number T = 1/2. Thus, nuclei have spin- and isospin-degrees of freedom.

Gamow-Teller (GT) transitions caused by the spin-isospin type operator, therefore, are unique tools for the studies of nuclear structure as well as nuclear interactions [1, 2].

They have been studied in β decays as well as charge-exchange (CE) reactions. In the past, however, accurate studies of GT transition in a wide range of excitation energy were difficult. In order to overcome the difficulties, we introduced high energy-resolution CE-type (3He,t) reaction, which opened a new scope in the GT transition studies [1].

We report the quantum selections rules relevant to spin and isospin quantum numbers. In addition, we started to observe the widths of short-lived states caused by the uncertainty principle [1].

[1] Y. Fujita, B. Rubio, and W. Gelletly, Prog. in Part. and Nucl. Phys. 66, 549 (2011).
[2] Y. Fujita, H. Fujita, T. Adachi, C.L. Bai et al., Phys. Rev. Lett. 112, 112502 (2014).

Coffee and tea will be served 20 minutes prior to the seminar.

Anyone interested is welcome to attend.