[en] The study of structural transitions of nuclei at high excitation energy and large angular momentum has led us a new phase in the study of nuclear structure. The major interest in this field is the study of evolution of nuclear shape under extreme conditions of spin and temperature. In recent times, a unified framework based on the Landau theory of phase transitions has been applied to explain the universal features of the nuclear shape transitions. Due to finite number of degrees of freedom, it is necessary to include thermal shape fluctuations in order to obtain good fits to experimental observables, such as GDR built on hot nuclei. The Landau theory offers a natural framework in which these thermal fluctuations are introduced

[en] Heating can have a profound effect on nuclear shapes, causing a variety of shape transitions. The possibility of heating the nucleus to a finite temperature opens a new direction in the study of nuclear structure. The major interest in this field is the study of evolution of nuclear shape under extreme conditions of spin and temperature. In recent times, a unified framework based on the Landau theory of phase transitions has been applied to explain the universal features of the nuclear shape transitions. Due to finite number of degrees of freedom, it is necessary to include thermal shape fluctuations in order to obtain good fits to experimental observables, such as GDR built on hot nuclei. The Landau theory offers a natural framework in which these thermal fluctuations are introduced

No abstract available

[en] The interacting boson model in its simplest form, as originally proposed, describes a system of s (l=0) and d (l=2) bosons which may interact with one another via one- or two-body interactions. The change in the structure of the nuclei have been proposed to be related with exceptionally strong neutron-proton interaction. Within the region of medium-heavy and heavy nuclei, a large number of nuclei exhibit properties that are neither closed to anharmonic vibrational spectra nor to deformed rotors. The standard description of these phenomena has been given in terms of nuclear triaxiality going from rigid triaxial shape to soft potential energy surfaces. Within the interacting boson model, when no distinction is made between proton and neutron variables, triaxiality can be described through the introduction of cubic term in the boson operators

[en] The symmetry and mixed-symmetry states of ^144-154Nd isotopes are studied via the framework of the proton-neutron interacting boson model. The F-spin values of theoretical energy states are also investigated. The calculated electromagnetic transition probabilities B(E2), B(M1) and the mixing ratio 𝛿(E2/ M1) are compared with available experimental data. The results obtained show that the 2+3 and 2+4 states have an 𝐹 = F_max - 1 value in the ¹⁴⁴Nd and ^146,14'8Nd isotopes, respectively. In the ^150-154Nd isotopes, the 1+1 state is the lowest mixed-symmetry state. (author)

No abstract available

[en] The heaviest isotope of praseodymium, ¹⁵⁴Pr, has been identified for the first time by γ-ray measurements of mass-separated activities obtained from a He-jet type on-line isotope separator for fission products of ²³⁵U. The Nd-K X-rays and 10 γ-rays have been assigned to be generated by the β-decay of ¹⁵⁴Pr. The half-life has been determined to be 2.3(1) s, which is not far from the theoretical predictions of 1.5 s and 4.0 s. (orig.)

[en] The DRAGON program was used to calculate 9600 samples, and the nuclide densities of ²³⁵U, ²³⁸U, ²³⁹Pu, ²⁴¹Pu, ¹³⁷Cs, ²⁴⁴Cm and ¹⁵⁴Nd nuclides were used as the prediction parameters. Linear regression model, regression tree model constructed based on decision tree, multilayer perception (MLP) model and random forest model were selected to carry out model training. Pearson correlation coefficient (PCC), mean absolute error (MAE), relative absolute error (RAE) and relative root mean square error (RRSE) were chosen to evaluate the fitting effect of the models;the trained models were used in the test set for the target. The trained models were used to predict the target nuclides in the test set, and their prediction accuracy was evaluated by relative errors. The results show that the training time of the data models is less than 3 s. After the evaluation of the selected parameters, the MLP model has the best training effect among the four models for all the predicted kernels, and its correlation is above 0.999. The average deviation of the MLP model for all the predicted kernels is less than 1%. This paper initially verifies the feasibility of data mining techniques in predicting the density of assembly nuclei. (authors)

[en] Short communication

[en] The decay of a new 3.2 μ, (4-) isomeric state at 1298.0 keV has been observed using γ-ray spectroscopy at the Lohengrin mass spectrometer of the Inst. Laue-Langevin. Prompt γ-ray data from a spontaneous fission experiment have also been analyzed allowing the observation of a collective band on top of this isomeric state, the identification of a new band on top of the previously reported (5-) isomer of ¹⁵⁶Nd and the extension of collective bands on top of (5-) isomers of the neighboring ^156,158Sm nuclei. Quasiparticle rotor model calculations correctly predict the energies and decay patterns of these bands. (authors)