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Nuclear Theory·nucl-th

Monday·July 17, 2017

7 papers—6 primary·1 cross-listed

All7Primary6Cross-lists1
  1. 01

    Effective field theory for triaxially deformed nuclei

    Q. B. Chen🇩🇪 · N. Kaiser🇩🇪 · Ulf-G. Meißner🇩🇪 · J. Meng🇨🇳

    Effective field theory (EFT) is generalized to investigate the rotational motion of triaxially deformed even-even nuclei. A Hamiltonian, called the triaxial rotor model (TRM), is obtained up to next-to-leading order (NLO) within the EFT formalism. Its applicability is examined by comparing with a five-dimensional collective Hamiltonian (5DCH) for the description of the energy spectra of the ground state and band in Ru isotopes. It is found that by taking into account the NLO corrections, the ground state band in the whole spin region and the band in the low spin region are well described. The results presented here indicate that it should be possible to further generalize the EFT to triaxial nuclei with odd mass number.

    nucl-thEPJA(2017)·17 citations
  2. 02

    Neutron-skin thickness determines the surface tension of a compressible nuclear droplet

    W. Horiuchi · S. Ebata · K. Iida

    We systematically investigate the neutron-skin thickness of neutron-rich nuclei within a compressible droplet model, which includes several parameters characterizing the surface tension and the equation of state (EOS) of asymmetric nuclear matter as well as corrections due to the surface diffuseness. Such a systematic analysis helps towards constraining the EOS parameters of asymmetric nuclear matter and the poorly known density dependence of the surface tension; the latter is estimated with help of available experimental data for the neutron and proton density distributions and the nuclear masses. Validity of the present approach is confirmed by calculating realistic density distributions of Ca, Ni, Zr, Sn, Yb, and Pb isotopes within a microscopic Skyrme-Hartree-Fock+BCS method for various sets of the effective nuclear force. Our macroscopic model accompanied by the diffuseness corrections works well in the sense that it well reproduces the evolution of the microscopically deduced neutron-skin thickness with respect to the neutron number for selected sets of the effective nuclear force. We find that the surface tension of the compressible nuclear droplet is a key to bridging a gap between microscopic and macroscopic approaches.

    nucl-thPRC(2017)·18 citations
  3. 03

    Transverse Momentum Fluctuations and Correlations

    Piotr Bozek🇵🇱 · Wojciech Broniowski🇵🇱 · Sandeep Chatterjee🇵🇱

    We study fluctuations and correlations of the average transverse momentum of particles emitted in heavy-ion collisions. Fluctuations of the average transverse momentum are related to event-by-event fluctuations of the size and entropy of the initial source. Hydrodynamic calculations using a Glauber model with quark degrees of freedom reproduce the data. We study correlations of the average transverse momentum in different rapidity bins. We propose a definition of the observable that can be directly related to correlations of the collective flow variables.

    nucl-thnucl-exActa Phys.Polon.Supp.(2017)·10 citations
  4. 04

    Alpha-like clustering in Ne from a quartetting wave function approach

    G. Röpke🇩🇪 · P. Schuck🇫🇷 · C. Xu🇨🇳 · Z. Ren🇨🇳 · M. Lyu🇨🇳 · B. Zhou🇯🇵 · Y. Funaki🇯🇵 · H. Horiuchi🇯🇵 · A. Tohsaki🇯🇵 · T. Yamada🇯🇵

    Quartetting (-like clustering) occurs in low density matter ( fm) which exists, e.g., at the surface of nuclei. It is of interest for the preformation to calculate the decay of heavy nuclei such as Po, but also in light nuclei (e.g., Ne) which shows strong signatures of quartetting. We analyze the intrinsic structure of the -like cluster and the center of mass motion of the quartet, in particular the role of Pauli blocking. The Thomas-Fermi model for the (daughter) core nucleus is improved introducing quasiparticle nucleon states. Calculations performed for harmonic oscillator basis states show that the effective potential for the quartet center of mass motion remains nearly constant within the core nucleus. The relation to the THSR (Tohsaki-Horiuchi-Schuck-Röpke) approach is discussed.

    nucl-thJ.Low Temp.Phys.(2017)·19 citations
  5. 05

    Assessing the foundation of the Trojan Horse Method

    C.A. Bertulani🇺🇸 · M.S. Hussein🇧🇷 · S. Typel🇩🇪

    We discuss the foundation of the Trojan Horse Method (THM) within the Inclusive Non-Elastic Breakup (INEB) theory. We demonstrate that the direct part of the INEB cross section, which is of two-step character, becomes, in the DWBA limit of the three-body theory with appropriate approximations and redefinitions, similar in structure to the one-step THM cross section. We also discuss the connection of the THM to the Surrogate Method (SM), which is a genuine two-step process.

    nucl-thnucl-exPLB(2018)·17 citations
  6. 06

    Systematic study of {\alpha} decay using different versions of proximity formalism

    O. N. Ghodsi · A. Daei-Ataollah

    Finding the best model to describe the {\alpha}-decay process is an old and ongoing challenge in nuclear physics. The present work systematically studied {\alpha}-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 {\alpha}-decay half-lives better than the other models. Comparison with fusion studies shows that Dutt 2011 is an appropriate model both for {\alpha}-decay studies and for prediction of the barrier characteristic in heavy-ion fusion reactions. The calculation of {\alpha}-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.

    nucl-thPRC(2016)·39 citations

Affiliations

first authorsco-authorsvia INSPIRE