Transition probabilities inGd154: Evidence for X(5) critical point symmetry

Lifetime measurements in $^{154}\mathrm{Gd}$ were performed by means of the recoil distance Doppler-shift method. Excited states of $^{154}\mathrm{Gd}$ were populated via Coulomb excitation with a $^{32}\mathrm{S}$ beam at $110\phantom{\rule{0.3em}{0ex}}\text{MeV}$ delivered by the FN tandem accelerator of the University of Cologne. The determined transition probabilities as well as the low-spin level scheme of $^{154}\mathrm{Gd}$ demonstrate a good agreement with the predictions of the critical point symmetry X(5). Comparison of specific experimental observables for the $N=90$ rare earth isotones with the calculations of the X(5) model clearly show that $^{154}\mathrm{Gd}$ is one of the good examples of the realization of the X(5) dynamical symmetry. In addition, the experimental data are compared to fits in the framework of the IBA and the general collective model.

[1]  R. Krücken,et al.  Comment on “Reexamination of theN=90transitional nucleiNd150andSm152” , 2003 .

[2]  K. Krane,et al.  Low-energy coexisting band in 154Gd. , 2003, Physical review letters.

[3]  M. Cromaz,et al.  B(E2)values and the search for the critical point symmetry X(5) in104Moand106Mo , 2003 .

[4]  P. Fallon,et al.  Reexamination of the N = 90 transitional nuclei 150 Nd and 152 Sm , 2003 .

[5]  P. Bizzeti,et al.  Evidence of X(5) symmetry for n γ =0,1,2 bands in 104 Mo , 2002 .

[6]  J. Cooper,et al.  B(E2) values in 150Nd and the critical point symmetry X(5). , 2002, Physical review letters.

[7]  R. Casten,et al.  Empirical realization of a critical point description in atomic nuclei. , 2001, Physical review letters.

[8]  F. Iachello.  Analytic description of critical point nuclei in a spherical-axially deformed shape phase transition. , 2001, Physical review letters.

[9]  A. Dewald,et al.  The value in 152Sm and β-softness in phase coexisting structures , 2000 .

[10]  Iachello.  Dynamic symmetries at the critical point , 2000, Physical review letters.

[11]  D. Kusnezov,et al.  Phase Transitions in Finite Nuclei and the Integer Nucleon Number Problem , 1999, nucl-ex/9905002.

[12]  R. Casten,et al.  Phase Coexistence in Transitional Nuclei and the Interacting-Boson Model , 1998 .

[13]  A. Stuchbery.  The attenuation of nuclear alignment along cascades in recoil-distance lifetime measurements , 1997 .

[14]  Chu,et al.  Multiparticle-rotor model for rotational band structure of 154Gd. , 1995, Physical review. C, Nuclear physics.

[15]  P. Petkov,et al.  The nuclear deorientation effect in 122Xe and 128Ba , 1995 .

[16]  Mach,et al.  Lifetime of the 21+ state in 154Gd and deduction of the alpha coefficient for the 21+-->01+ transition. , 1995, Physical review. C, Nuclear physics.

[17]  P. Nolan,et al.  Electromagnetic transition probabilities in 130Ce , 1992 .

[18]  K. Kumar,et al.  Analysis of 154Gd by the dynamic deformation model , 1990 .

[19]  M. Riley,et al.  Rotational band structures in 154Gd , 1989 .

[20]  S. Harissopulos,et al.  The differential plunger and the differential decay curve method for the analysis of recoil distance Doppler-shift data , 1989 .

[21]  A. Arima,et al.  The Interacting Boson Model: The interacting boson model-2 , 1987 .

[22]  E. Nadjakov,et al.  Microscopic determination of band interaction in 154Gd and 164Er , 1982 .

[23]  H. R. Andrews,et al.  Measurement of lifetimes for high spin states in 152Sm, 154Gd and 156Gd by the Doppler broadened lineshape method , 1977 .

[24]  R. A. Fox,et al.  Multipole mixing ratios of transitions in 15'Gd , 1983 .

[25]  G. Ewan,et al.  Measurement of lifetimes in 152Sm, 154Gd and 156Gd by doppler-shlft recoil-distance techniques , 1972 .

[26]  K. Kumar.  PAIRING-PLUS-QUADRUPOLE MODEL CALCULATION OF BAND-MIXING ANOMALIES IN $sup 152$Sm. , 1971 .