$\alpha$ -decay energies of superheavy nuclei: Systematic trends

Journal Article · 25 January 2019 · Physical Review C

DOI: https://doi.org/10.1103/PhysRevC.99.014317 · OSTI ID:1513812

Olsen, E. ^[1]; Nazarewicz, W. ^[2]

---

1. Michigan State Univ., East Lansing, MI (United States); FRIB/MSU
2. Michigan State Univ., East Lansing, MI (United States)

Background: New superheavy nuclei are often identified through their characteristic α -decay energies, which requires accurate calculations of Q_α values. While many Q_α predictions are available, little is known about their uncertainties, and this makes it difficult to carry out extrapolations to as-yet-unknown systems. Purpose: This work aims to analyze several models, compare their predictions to available experimental data, and study their performance for the unobserved α-decay chains of ²⁹⁶120 and ²⁹⁸120, which are of current experimental interest. Our quantified results will also serve as a benchmark for future, more sophisticated statistical studies. Methods: We use nuclear superfluid density functional theory (DFT) with several Skyrme energy density functionals (EDFs). To estimate systematic model uncertainties, we employ uniform model averaging. Results: We investigated the Q_αvalues for even-even nuclei from Fm to Z = 120 . For well-deformed nuclei between Fm and Ds, we find excellent consistency between different model predictions, and a good agreement with experimental results. For transitional nuclei beyond Ds, intermodel differences grow, resulting in an appreciable systematic error. In particular, our models underestimate Q_α for the heaviest nucleus ²⁹⁴Og. Conclusions The robustness of DFT predictions for well-deformed superheavy nuclei supports the idea of using experimental Q_α values, together with theoretical predictions, as reasonable (Z, A) indicators. Unfortunately, this identification method is not projected to work well in the region of deformed-to-spherical shape transition as one approaches N = 184 . The use of Q_α values in the identification of new superheavy nuclei will benefit greatly from progress in developing both new spectroscopic-quality EDFs and more sophisticated statistical techniques of uncertainty quantification.

• Research Organization: Michigan State Univ., East Lansing, MI (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
• Grant/Contract Number: NA0002847; NA0003885; SC0008511; SC0013365; SC0018083
• OSTI ID: 1513812
• Journal Information: Physical Review C, Journal Name: Physical Review C Journal Issue: 1 Vol. 99; ISSN PRVCAN; ISSN 2469-9985
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English