Re-investigation of heat capacity and paring phase transition in hot ${}^{93-98}$Mo nuclei

Abstract

The empirical heat capacities of ${}^{93-98}$Mo nuclei are re-investigated by using the latest updated and recommended nuclear level density (NLD) data below the neutron binding energy $B_n$ combined with the back-shifted Fermi-gas (BSFG) model for the energy region above $B_n$. For the latter, the BSFG formula with energy-dependent level density parameter is used and the new parameterization has been carried out in order to obtain the best fit to the new NLD data in the whole data range. The results obtained show that the S-shaped heat capacity, a fingerprint of the pairing phase transition, is more pronounced in even ${}^{94,96,98}$Mo nuclei than that in odd ${}^{93,95,97}$Mo isotopes. This result is different with those obtained in two previous studies by R. Chankova et al., [Phys. Rev. C {\bf 73}, 034311 (2006)] and K. Kaneko et al., [Phys. Rev. C {\bf 74}, 024325 (2006)], in which the old NLD data and the BSFG model with energy-independent level density parameter were used. Moreover, the present work suggests that the very strong S-shape observed in the heat capacities of both even and odd Molybdenum isotopes by K. Kaneko et al., [Phys. Rev. C {\bf 74}, 024325 (2006)] should be re-investigated. The present work also suggests that obtain the correct heat capacity and associated pairing phase transition in excited nuclei, one should use the correct NLD data and the best fitted BSFG NLD in the entire region where the experimental data are available.

arXiv comment6 pages, 3 figures. Accepted in Eur. Phys. J. A

References in corpus (13)

• Nuclear Level Density and the Determination of Thermonuclear Rates for Astrophysics
• Critical temperature for quenching of pair correlations
• Gamma-ray strength function and pygmy resonance in rare earth nuclei
• Observation of Thermodynamical Properties in the ${}^{162}$Dy, ${}^{166}$Er and ${}^{172}$Yb Nuclei
• Signature of a Pairing Transition in the Heat Capacity of Finite Nuclei
• Level densities and thermodynamical quantities of heated 93-98Mo isotopes
• Transitional $\gamma$ strength in Cd isotopes
• Experimental level densities of atomic nuclei
• Thermodynamics of pairing in mesoscopic systems
• Breaking of nucleon Cooper pairs at finite temperature in 93-98Mo
• Exact and approximate ensemble treatments of thermal pairing in a multilevel model
• Canonical and microcanonical ensemble descriptions of thermal pairing within BCS and quasiparticle RPA
• Thermodynamic properties of hot nuclei within the self-consistent quasiparticle random-phase approximation