题目：Transverse Wobbling in Nuclei
报告人：U. Garg教授
单位：University of Notre Dame
时间：2015年3月11日（周三）上午10:00
地点：北京大学加速器楼408
报告摘要：
Wobbling of triaxial even-even nuclei represents the quantized
oscillations of the principal axes of an asymmetric top relative to the
space-fixed angular momentum vector or, in the body fixed frame of
reference, the oscillations of the angular momentum vector about the axis
of the largest moment of inertia [1]. In transverse wobbling, the odd
quasiproton, with predominantly particle nature, aligns its angular
momentum vector **j** along the short axis of the triaxial rotor, i.e.,
perpendicular to the axis with the largest moment of inertia [2]. The
result is a pair of bands corresponding to wobbling phonons n**w**=0 and n*
*w**=1.*
In a series of measurements with Gammasphere and INGA, we have identified
“wobbler partner” bands in the nucleus 135Pr, the first observation of
wobbling in a mass region other than near A~160. The nature of wobbler
bands is confirmed by verifying the Delta-I=1, E2 character of the
inter-band transitions via angular distribution and polarization
measurements. The transverse nature of wobbling is evidenced by the
characteristic decrease in Ewobb [2]. The wobbling structure evolves into a
three-quasiparticle band of the magnetic rotation type. The observations
are in accordance with Quasiparticle-triaxial-rotor (QTR) and
Tilted-axis-cranking (TAC) calculations.
[1] A. Bohr and B. R. Mottelson, Nuclear Structure II (Benjamin, 1975).
[2] S. Frauendorf and F. Dönau, Phys. Rev. C 89, 014322 (2014).