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Nuclear Theory·nucl-th

Tuesday·June 12, 2018

7 papers—3 primary·4 cross-listed

All7Primary3Cross-lists4
  1. 01

    Systematic investigation of the Hoyle-analog states in light nuclei

    V. S. Vasilevsky · K. Katō · N. Takibayev

    We investigate resonance states in three-cluster continuum of some light nuclei Be, B, B, B and C. These nuclei are considered to have a three-cluster configuration consisting of two alpha-particles and neutron, proton, deuteron, triton and nucleus He. In this study, we make use two different microscopic three-cluster models. The first model employs the Hyperspherical Harmonics basis to numerate channels and describe three-cluster continuum. The second model is the well-known complex scaling method. The nucleon-nucleon interaction is modeled by the semi-realistic Minnesota and Hasegawa-Nagata potentials. Our main aim is to find the Hoyle-analog states in these nuclei or, in other words, whether it is possible to synthesize these nuclei in a triple collision of clusters. We formulate the criteria for selecting such states and apply them to resonance states, emerged from our calculations. We found that there are resonance states obeying the formulated criteria which make possible syntheses of these nuclei in a stellar environment.

    nucl-thPRC(2018)·8 citations
  2. 02

    Effects of quark-matter symmetry energy on hadron-quark coexistence in neutron-star matter

    Xuhao Wu🇨🇳 · Akira Ohnishi🇯🇵 · Hong Shen🇨🇳

    We examine the effects of the isovector-vector coupling and hypercharge-vector coupling in quark matter on hadron-quark coexistence in neutron-star matter. The relativistic mean field theory with the TM1 parameter set and an extended TM1 parameter set are used to describe hadronic matter, and the Nambu-Jona-Lasinio model with scalar, isoscalar-vector, isovector-vector and hypercharge-vector couplings is used to describe deconfined quark matter. The hadron-quark phase transition is constructed via the Gibbs conditions for phase equilibrium. The isovector-vector and hypercharge-vector couplings in quark matter enhance the symmetry energy and hypercharge symmetry energy in neutron-star matter, while their effects are found to be suppressed at high densities by the strange quarks. As a result, the hadron-quark mixed phase shrinks with only isovector-vector coupling and moves to higher density with isovector-vector and hypercharge-vector couplings. The maximum mass of neutron-star increases slightly with isovector-vector and hypercharge-vector couplings.

    nucl-thPRC(2018)·24 citations
  3. 03

    Explicit inclusion of spin-orbit contribution in THSR wave function

    N. Itagaki · H. Matsuno · A. Tohsaki

    The Tohsaki-Horiuchi-Schuck-Roepke (THSR) wave function has been successfully used for the studies of gas-like nature of alpha clusters in various nuclei including the so-called Hoyle state of 12C and four alpha states of 16O. In standard alpha cluster models, however, each alpha cluster wave function has spin zero because of its spatial symmetry and antisymmetrization effect. Thus the non-central interactions do not contribute, and this situation is the same in the THSR wave function. In this work, the spin-orbit contribution, which is found to be quite important at short alpha-alpha distances, is taken into account in the THSR wave function by combing it with antisymmetrized quasi cluster model (AQCM). The application to 12C is presented. The multi-integration in the original THSR wave function is carried out by using Monte Carlo technique, which is called Monte Carlo THSR wave function. For the nucleon-nucleon interaction, the Tohsaki interaction, which contains finite-range three-body terms and simultaneously reproduces the saturation properties of nuclear systems, the alpha-alpha scattering phase shift, and the size and binding energy of 4He, is adopted.

    nucl-thnucl-exPRC(2018)·17 citations
  4. 04

    On the Threshold Resummation in Forward pA Collisions

    Bo-Wen Xiao🇨🇳 · Feng Yuan🇺🇸

    In this paper, using the Higgs production in forward rapidity region in proton-nucleus collisions as an example, we demonstrate that we can construct a systematic formalism for the threshold resummation for forward rapidity particle productions in the saturation formalism. The forward threshold jet function, which satisfies the corresponding renormalization group equation, is introduced into the new factorization formula. This calculation can be easily generalized to other processes, such as single forward hadron productions at forward rapidity region, and have important phenomenological implications.

    ↳ hep-phnucl-thPLB(2019)·16 citations
  5. 05

    Nuclear charge radii of Th from isotope and isomer shifts

    M. S. Safronova · S. G. Porsev · M. G. Kozlov · J. Thielking · M. V. Okhapkin · P. Głowacki · D. M. Meier · E. Peik

    The isotope Th is unique in that it possesses an isomeric state of only a few eV above the ground state, suitable for nuclear laser excitation. An optical clock based on this transition is expected to be a very sensitive probe for variations of fundamental constants, but the nuclear properties of both states have to be determined precisely to derive the actual sensitivity. We carry out isotope shift calculations in Th and Th including the specific mass shift, using a combination of configuration interaction and all-order linearized coupled-cluster methods and estimate the uncertainty of this approach. We perform experimental measurements of the hyperfine structure of Th and isotopic shift between Th and Th to extract the difference in root-mean-square radii as fm. Using the recently measured values of the isomer shift of lines of Th, we derive the value for the mean-square radius change between Th and its low lying isomer Th to be .

    ↳ physics.atom-phnucl-exnucl-thquant-phPRL(2018)·27 citations
  6. 06

    Modeling of two-particle femtoscopic correlations at top RHIC energy

    N. Ermakov🇷🇺 · G. Nigmatkulov🇷🇺

    The spatial and temporal characteristics of particle emitting source produced in particle and/or nuclear collisions can be measured by using two-particle femtoscopic correlations. These correlations arise due to quantum statistics, Coulomb and strong final state interactions. In this paper we report on the calculations of like-sign pion femtoscopic correlations produced in p+p, p+Au, d+Au, Au+Au at top RHIC energy using Ultra Relativistic Quantum Molecular Dynamics Model (UrQMD). Three-dimensional correlation functions are constructed using the Bertsch-Pratt parametrization of the two-particle relative momentum. The correlation functions are studied in several transverse mass ranges. The emitting source radii of charged pions, Rout , Rside , Rlong , are obtained from Gaussian fit to the correlation functions and compared to data from the STAR and PHENIX experiments.

    ↳ nucl-exnucl-thJ.Phys.Conf.Ser.(2017)·5 citations
  7. 07

    Crustal heating in accreting neutron stars from the nuclear energy-density functional theory. I. Proton shell effects and neutron-matter constraint

    A.F. Fantina🇫🇷 · J.L. Zdunik🇵🇱 · N. Chamel🇧🇪 · J.M. Pearson🇨🇦 · P. Haensel🇵🇱 · S. Goriely🇧🇪

    Observations of soft X-ray transients in quiescence suggest the existence of heat sources in the crust of accreting neutron stars. Heat is thought to be released by electroweak and nuclear processes triggered by the burying of ashes of X-ray bursts. The heating is studied using a fully quantum approach taking consistently into account nuclear shell effects. We have followed the evolution of ashes made of Fe employing the nuclear energy-density functional theory. Both the outer and inner crusts are described using the same functional, thus ensuring a unified and thermodynamically consistent treatment. To assess the role of the neutron-matter constraint, we have employed the set of accurately calibrated Brussels-Montreal functionals BSk19, BSk20, and BSk21 and for comparison the SLy4 functional. Due to nuclear shell effects, the fully accreted crust is found to be much less stratified than in previous studies. In particular, large regions of the inner crust contain clusters with the magic number . The heat deposited in the outer crust is tightly constrained by experimental atomic mass data. The shallow heating we obtain does not exceed ~MeV and is therefore not enough to explain the cooling of some soft X-ray transients. The total heat released in the crust is very sensitive to details of the nuclear structure and is predicted to lie in the range from ~MeV to ~MeV. The evolution of an accreted matter element and therefore the location of heat sources are governed to a large extent by the existence of nuclear shell closures. Ignoring these effects in the inner crust, the total heat falls to ~MeV. The neutron-matter constraint is also found to play a key role. The large amount of heat obtained by Steiner et al. (2012) could thus be traced back to unrealistic neutron-matter equations of state.

    ↳ astro-ph.HEnucl-thAstron.Astrophys.(2018)·49 citations

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first authorsco-authorsvia INSPIRE