Search arXiv⌕ Search

arXiv · 1707.04568

Systematic study of α decay using different versions of proximity formalism

Abstract

Finding the best model to describe the α-decay process is an old and ongoing challenge in nuclear physics. The present work systematically studied α-decay half-lives for the favored ground-state-to-ground-state transitions of 344 isotopes of nuclei with 52 <= Z <= 107 using 28 versions of the proximity potential model in the framework of the WKB approximation. The present study introduces the best proximity versions with the fewest deviations with respect to experimental values. The models for Prox. 77-set 4, Prox. 77-set 5, and Dutt 2011 with the root-mean-square deviations (RMSDs) of <1 were found to predict α-decay half-lives better than the other models. Comparison with fusion studies shows that Dutt 2011 is an appropriate model both for α-decay studies and for prediction of the barrier characteristic in heavy-ion fusion reactions. The calculation of α-decay half-lives were repeated for even-even, even-odd, odd-even, and odd-odd nuclei. This detailed comparative study reveals that for these versions the half-lives of the even-even nuclei with RMSDs of <0.6 show less deviation than the even-odd, odd-even, and odd-odd nuclei.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

O. N. Ghodsi, A. Daei-Ataollah. 2017-07-14. Systematic study of α decay using different versions of proximity formalism. https://doi.org/10.1103/physrevc.93.024612

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Intertwined quantum phase transitions in the even-even $^{90-100}$Sr isotopes

The even-even $^{90-100}$Sr isotopes are identified as a region of intertwined quantum phase transitions (IQPTs). In this scenario, a quantum phase transition involving the crossing of normal and intruder configurations is accompanied by a shape evolution within the intruder configuration. Using the interacting boson model with configuration mixing (IBM-CM), its is shown that the strontium chain exhibits the IQPT scenario, where the intruder configuration evolves from a near-spherical structure in $^{90\text{--}96}$Sr to a deformed one in $^{98,100}$Sr, while the normal and intruder configurations cross between $^{96}$Sr and $^{98}$Sr. As a result, the ground state changes abruptly from a weakly collective normal configuration to a deformed intruder configuration. Evidence for this scenario is provided by a detailed comparison with experimental excitation energies, isotope shifts, and monopole $E0$ transition strengths, together with the configuration and $n_d$ decompositions of the calculated wave functions. The results place the strontium isotopes alongside the neighboring zirconium chain as a realization of IQPTs in the intricate $A\approx100$ region.

nucl-th↗

Strangeness Production in Heavy-Ion Collisions: Color Ropes or Hydrodynamic Evolution?

We investigate strangeness production and transverse dynamics in heavy-ion collisions at $\sqrt{s_{\mathrm{NN}}}\approx 2.5-20~\mathrm{GeV}$ using the transport approach SMASH (Simulating Many Accelerated Strongly-interacting Hadrons), its extension with rope hadronization, and the SMASH+vHLLE hybrid approach. Results from the Pythia-based heavy-ion model Angantyr, with and without rope hadronization, are included for comparison. We study midrapidity particle yields and average transverse masses as functions of the number of wounded nucleons, as well as their energy dependence. For the $K^+/π^+$ ratio, SMASH+vHLLE overpredicts strangeness production at low energies but describes the higher-energy behavior reasonably well. SMASH+Ropes reproduces the ratio up to $\sqrt{s_{\mathrm{NN}}}\sim 10~\mathrm{GeV}$ but does not capture the turnover at higher energies. In contrast, the transverse-mass observables favor the hybrid approach, while the non-thermal models considered here do not generate sufficient collective transverse expansion. These results show that strangeness enhancement alone does not uniquely distinguish microscopic string interactions from a locally equilibrated medium. Simultaneously constraining strangeness production and transverse dynamics is therefore essential for disentangling thermal and non-thermal mechanisms in heavy-ion collisions.

nucl-th↗

Constraining Energy Density Functionals via Bayesian Analysis of Nuclear Densities

In nuclear many-body physics, energy density functional (EDF) theory is one of the most powerful approaches for describing finite nuclei and nuclear matter. However, its predictive capability depends on calibrating model parameters to experimental and observational data. In this work, we investigate an alternative approach: Constraining the parameters with the continuous density profiles of finite nuclei obtained from ab initio calculations. We apply Bayesian analysis to infer the parameters of Skyrme EDF from the density profiles and binding energies of 16O, 40Ca, and 48Ca. We show that the data effectively constrain the parameters associated with the properties of uniform nuclear matter, whereas those governing non-uniform nuclear matter remain partially constrained and require additional input. Furthermore, using the inferred parameter distributions, we successfully predict the density profiles and binding energy of 208Pb, which is excluded from the training data. This demonstrates the predictive capability of the framework. In conclusion, these results establish Bayesian analysis of density profiles as a promising route for incorporating accurate ab initio results of light nuclei into EDF development and strengthening the connection between both approaches.

nucl-th↗