Optimal temperature for alpha-decay half-lives with Yukawa proximity potential

The paper investigates the alpha-decay half-lives of some nuclei by modifying the Coulomb potential with Yukawa proximity potential for the excited state decays. A new relation is found for the width diffuseness of the nuclear surface [Formula: see text] and the sharp radii [Formula: see text] for the excited system. The parameters are fitted to the experimental data for the nuclear temperature in the range [Formula: see text] (MeV). A comparison of half-life indicates that the probability of decay increases with increasing nuclear temperature for the excited system. The comparison of the results with the existing experimental data is motivating.

Velocity fluctuations of fission fragments

We propose event by event velocity fluctuations of nuclear fission fragments as an additional interesting observable that gives access to the nuclear temperature in an independent way from spectral measurements and relates the diffusion and friction coefficients for the relative fragment coordinate in Kramers-like models (in which some aspects of fission can be understood as the diffusion of a collective variable through a potential barrier). We point out that neutron emission by the heavy fragments can be treated in effective theory if corrections to the velocity distribution are needed.

Excited quasiparticles and entropy in 161,162Dy

In this paper, the nuclear level densities of [Formula: see text]Dy is studied by the use of a microscopic theory which includes nuclear pairing interaction. It is based on the modified harmonic oscillator model according to the Nilsson potential. The entropy of even–odd and even–even nuclei as a function of nuclear temperature is obtained. The entropy excess of [Formula: see text]Dy is compared with that of [Formula: see text]Dy. It is concluded that the difference is related to the entropy carried by the neutron hole coupled to the even–even core. The numbers of excited quasiparticles are calculated. Good agreement was observed between calculated results and the experimental data.

The entropy excess and moment of inertia excess ratio with inclusion of statistical pairing fluctuations

The entropy excess of 163 Dy compared to 162 Dy as a function of nuclear temperature have been investigated using the mean value Bardeen–Cooper–Schrieffer (BCS) method based on application of the isothermal probability distribution function to take into account the statistical fluctuations. Then, the spin cut-off excess ratio (moment of inertia excess ratio) introduced by Razavi [Phys. Rev. C88 (2013) 014316] for proton and neutron system have been obtained and are compared with their corresponding data on the BCS model. The results show that the overall agreement between the BCS model and mean value BCS method is satisfactory and the mean value BCS model reduces fluctuations and washes out singularities. However, the expected constant value in the entropy excess is not reproduced by the mean value BCS method.

On Antiproton Production in 158 GeV/cProton-Carbon Collisions and Nuclear Temperature of Interacting System

The multisource thermal model is used in this paper to analyze the antiproton (p¯) production process in high-energy proton-carbon (p-C) collisions. The transverse momentum, Feynman variable, and rapidity distributions of antiprotons in the nucleon-nucleon center-of-mass system are calculated by using the model. The modeling results are compared and found to be in agreement with the experimental data measured by the NA49 Collaboration at 158 GeV/cbeam momentum. As a parameter, the nuclear temperature of interacting system extracted from the antiproton spectrum is estimated to be about 150 MeV.