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Title: Shell-model test of the rotational-model relation between static quadrupole moments Q(2{sub 1}{sup +}),B(E2)'s, and orbital M1 transitions

Abstract

In this work, we examine critically the relation between orbital magnetic dipole (scissors mode) strength and quadrupole deformation properties. Assuming a simple K=0 ground-state band in an even-even nucleus, the quantities Q(2{sub 1}{sup +}) (i.e., the static quadrupole moment) and B(E2){sub 0{sub 1}}{sub {yields}}{sub 2{sub 1}} both are described by a single parameter--the intrinsic quadrupole moment Q{sub 0}. In the shell model, we can operationally define Q{sub 0}(static) and Q{sub 0}(BE2) and see if they are the same. Following a brief excursion to the sd shell, we perform calculations in the fp shell. The nuclei we consider ({sup 44,46,48}Ti and {sup 48,50}Cr) are far from being perfect rotors, but we find that the calculated ratios Q{sub 0}(static)/Q{sub 0}(BE2) with an FPD6 interaction are often very large (very close to unity) and far from the simple vibrational limit of zero. The experimental ratios for {sup 46}Ti and {sup 48}Ti are somewhat smaller ({approx}0.75), but the {sup 50}Cr value is larger, exceeding unity. We also discuss the quadrupole collectivity of orbital magnetic dipole transitions. We find that the large orbital B(M1) strength in {sup 44}Ti relative to {sup 46}Ti and {sup 48}Ti cannot be explained by simple deformation arguments.

Authors:
; ; ; ; ;  [1];  [2];  [3];  [4]
  1. Geology and Physics Department, University of Southern Indiana, Evansville, Indiana 47712 (United States)
  2. (United States)
  3. (Germany)
  4. (South Africa)
Publication Date:
OSTI Identifier:
20771405
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 73; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevC.73.037306; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; CHROMIUM 50; COLLECTIVE MODEL; DEFORMED NUCLEI; E2-TRANSITIONS; GROUND STATES; M1-TRANSITIONS; MAGNETIC DIPOLES; NUCLEAR DEFORMATION; NUCLEAR ELECTRIC MOMENTS; NUCLEAR MAGNETIC MOMENTS; PROBABILITY; QUADRUPOLE MOMENTS; QUADRUPOLES; ROTATIONAL STATES; SHELL MODELS; TITANIUM 44; TITANIUM 46; TITANIUM 48

Citation Formats

Robinson, S.J.Q., Escuderos, A., Zamick, L., Neumann-Cosel, P. von, Richter, A., Fearick, R.W., Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt, and Physics Department, University of Cape Town, Rondebosch 7700. Shell-model test of the rotational-model relation between static quadrupole moments Q(2{sub 1}{sup +}),B(E2)'s, and orbital M1 transitions. United States: N. p., 2006. Web. doi:10.1103/PhysRevC.73.037306.
Robinson, S.J.Q., Escuderos, A., Zamick, L., Neumann-Cosel, P. von, Richter, A., Fearick, R.W., Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt, & Physics Department, University of Cape Town, Rondebosch 7700. Shell-model test of the rotational-model relation between static quadrupole moments Q(2{sub 1}{sup +}),B(E2)'s, and orbital M1 transitions. United States. doi:10.1103/PhysRevC.73.037306.
Robinson, S.J.Q., Escuderos, A., Zamick, L., Neumann-Cosel, P. von, Richter, A., Fearick, R.W., Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt, and Physics Department, University of Cape Town, Rondebosch 7700. Wed . "Shell-model test of the rotational-model relation between static quadrupole moments Q(2{sub 1}{sup +}),B(E2)'s, and orbital M1 transitions". United States. doi:10.1103/PhysRevC.73.037306.
@article{osti_20771405,
title = {Shell-model test of the rotational-model relation between static quadrupole moments Q(2{sub 1}{sup +}),B(E2)'s, and orbital M1 transitions},
author = {Robinson, S.J.Q. and Escuderos, A. and Zamick, L. and Neumann-Cosel, P. von and Richter, A. and Fearick, R.W. and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854 and Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt and Physics Department, University of Cape Town, Rondebosch 7700},
abstractNote = {In this work, we examine critically the relation between orbital magnetic dipole (scissors mode) strength and quadrupole deformation properties. Assuming a simple K=0 ground-state band in an even-even nucleus, the quantities Q(2{sub 1}{sup +}) (i.e., the static quadrupole moment) and B(E2){sub 0{sub 1}}{sub {yields}}{sub 2{sub 1}} both are described by a single parameter--the intrinsic quadrupole moment Q{sub 0}. In the shell model, we can operationally define Q{sub 0}(static) and Q{sub 0}(BE2) and see if they are the same. Following a brief excursion to the sd shell, we perform calculations in the fp shell. The nuclei we consider ({sup 44,46,48}Ti and {sup 48,50}Cr) are far from being perfect rotors, but we find that the calculated ratios Q{sub 0}(static)/Q{sub 0}(BE2) with an FPD6 interaction are often very large (very close to unity) and far from the simple vibrational limit of zero. The experimental ratios for {sup 46}Ti and {sup 48}Ti are somewhat smaller ({approx}0.75), but the {sup 50}Cr value is larger, exceeding unity. We also discuss the quadrupole collectivity of orbital magnetic dipole transitions. We find that the large orbital B(M1) strength in {sup 44}Ti relative to {sup 46}Ti and {sup 48}Ti cannot be explained by simple deformation arguments.},
doi = {10.1103/PhysRevC.73.037306},
journal = {Physical Review. C, Nuclear Physics},
number = 3,
volume = 73,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}