Eur. Phys. J. A (2013) 49: 152
https://doi.org/10.1140/epja/i2013-13152-2

Regular Article - Theoretical Physics

One-phonon octupole vibrational states in ²¹¹At, ²¹²Rn, ²¹³Fr and ²¹⁴Ra with N = 126

Physics Department, Vanderbilt University, 37235, Nashville, TN, USA

^* e-mail: jae-kwang.hwang@vanderbilt.edu

Received: 18 October 2013
Revised: 21 November 2013
Accepted: 26 November 2013
Published online: 12 December 2013

Abstract

Excited high spin states in ²¹¹At, ²¹²Rn, ²¹³Fr and ²¹⁴Ra with N = 126 are reorganized and interpreted in terms of the stretched weak coupling of an octupole 3⁻ phonon. Nearly identical sequences of levels with ΔI = 3 and the parity change are found, for the first time, up to 25⁻ for 20 states of ²¹⁴Ra, up to 35⁻ for 36 states of ²¹²Rn and up to 53/2⁺ for 16 states of ²¹³Fr. The stretched weak coupling of an octupole phonon is extended up to the highest excitation energy of 11355 keV for ²¹²Rn which has the largest experimental B(E3) value of 44.1(88) W.u. for the 11⁻ → 8 ₂ ⁺ transition. The stretched weak coupling of an octupole 3⁻ phonon needs to be considered when single particle configurations are assigned to high spin states. Average octupole excitation energies of 657(51) keV for ²¹¹At, 1101(28) keV for ²¹²Rn, 667(25) keV for ²¹³Fr, and 709(25) keV for ²¹⁴Ra are obtained. The calculated level enegies are in a good agreement with the experimental level energies within the error limit of 4.3%.