PaperPanorama
FAQ

Nuclear Theory·nucl-th

Monday·November 27, 2017

13 papers—9 primary·4 cross-listed

All13Primary9Cross-lists4
  1. 01

    Hydrodynamic predictions for 5.44 TeV Xe+Xe collisions

    Giuliano Giacalone🇫🇷 · Jacquelyn Noronha-Hostler🇺🇸 · Matthew Luzum🇧🇷 · Jean-Yves Ollitrault🇫🇷

    We argue that relativistic hydrodynamics is able to make robust predictions for soft particle production in Xe+Xe collisions at the CERN Large Hadron Collider (LHC). The change of system size from Pb+Pb to Xe+Xe provides a unique opportunity to test the scaling laws inherent to fluid dynamics. Using event-by-event hydrodynamic simulations, we make quantitative predictions for several observables: mean transverse momentum, anisotropic flow coefficients, and their fluctuations. Results are shown as function of collision centrality.

    nucl-thhep-phnucl-exPRC(2018)·139 citations
  2. 02

    Proxy-SU(3): A symmetry for heavy nuclei

    D. Bonatsos · I.E. Assimakis · N. Minkov · A. Martinou · S. K. Peroulis · S. Sarantopoulou · R.B. Cakirli · R.F. Casten · K. Blaum

    The SU(3) symmetry realized by J. P. Elliott in the sd nuclear shell is destroyed in heavier shells by the strong spin-orbit interaction. On the other hand, the SU(3) symmetry has been used for the description of heavy nuclei in terms of bosons in the framework of the Interacting Boson Approximation, as well as in terms of fermions using the pseudo-SU(3) approximation. A new fermionic approximation, called the proxy-SU(3), has been recently introduced and applied to the even rare earths. We show that the applicability of proxy-SU(3) can be extended to even nuclei in the 28-50 proton shell, to even superheavy elements, as well as to odd-odd and odd rare earths. Parameter free predictions for the beta and gamma deformation parameters are presented and compared to alternative theoretical predictions and to existing data.

    nucl-thBulg.J.Phys.(2017)·10 citations
  4. 04

    Semilocal momentum-space regularized chiral two-nucleon potentials up to fifth order

    P. Reinert🇩🇪 · H. Krebs🇩🇪 · E. Epelbaum🇩🇪

    We introduce new semilocal two-nucleon potentials up to fifth order in the chiral expansion. We employ a simple regularization approach for the pion-exchange contributions which (i) maintains the long-range part of the interaction, (ii) is implemented in momentum space and (iii) can be straightforwardly applied to regularize many-body forces and current operators. We discuss in detail the two-nucleon contact interactions at fourth order and demonstrate that three terms out of fifteen used in previous calculations can be eliminated via suitably chosen unitary transformations. The removal of the redundant contact terms results in a drastic simplification of the fits to scattering data and leads to interactions which are much softer (i.e. more perturbative) than our recent semilocal coordinate-space regularized potentials. Using the pion-nucleon low-energy constants from matching pion-nucleon Roy-Steiner equations to chiral perturbation theory, we perform a comprehensive analysis of nucleon-nucleon scattering and the deuteron properties up to fifth chiral order and study the impact of the leading F-wave two-nucleon contact interactions which appear at sixth order. The resulting chiral potentials lead to an outstanding description of the proton-proton and neutron-proton scattering data from the self-consistent Granada-2013 database below the pion production threshold, which is significantly better than for any other chiral potential. For the first time, the chiral potentials match in precision and even outperform the available high-precision phenomenological potentials, while the number of adjustable parameters is, at the same time, reduced by about ~40%. Last but not least, we perform a detailed error analysis and, in particular, quantify for the first time the statistical uncertainties of the fourth- and the considered sixth-order contact interactions.

    nucl-thhep-phnucl-exEPJA(2018)·369 citations
  6. 06

    Exploring manifestation and nature of a dineutron in two-neutron emission using a dynamical dineutron model

    L.V. Grigorenko · J.S. Vaagen · M.V. Zhukov

    Emission of two neutrons or two protons in reactions and decays is often discussed in terms of "dineutron" or "diproton" emission. The discussion often leans intuitively on something described by Migdal-Watson approximation. In this work we propose a way to formalize situations of dineutron emission. It is demonstrated that properly formally defined dineutron emission may reveal properties which are drastically different from those traditionally expected, and properties which are actually observed in three-body decays.

    nucl-thPRC(2018)·17 citations
  7. 07

    Individual low-energy toroidal dipole state in Mg

    V.O. Nesterenko · A. Repko · J. Kvasil · P.-G. Reinhard

    The low-energy dipole excitations in Mg are investigated within the Skyrme quasiparticle random-phase-approximation (QRPA) for axial nuclei. The calculations with the force SLy6 reveal a remarkable feature: the lowest excitation (E = 7.92 MeV) in Mg is a vortical toroidal state (TS) representing a specific vortex-antivortex realization of well-known spherical Hill's vortex in a strongly deformed axial confinement. This is a striking example of an {\it individual} TS which can be much easier discriminated in experiment than the toroidal dipole resonance embracing many states. The TS acquires the lowest energy due to the huge prolate axial deformation in Mg. The result persists for different Skyrme parameterizations (SLy6, SVbas, SkM*). We analyze spectroscopic properties of the TS and its relation with the cluster structure of Mg. Similar TS could exist in other highly prolate light nuclei. They could serve as promising tests for various reactions to probe a vortical (toroidal) nuclear flow.

    nucl-thPRL(2018)·30 citations
  8. 08

    Phase Transitions in Dense and Hot Matter

    Veronica Dexheimer🇺🇸

    In this conference proceeding, I discuss in detail the deconfinement to quark matter that takes place at large densities and/or temperatures. The first-order phase transition that is assumed to appear beyond a critical point gives rise to mixtures of phases when more than one globally conserved quantity (such as charge fraction) is imposed. The modifications caused by these mixtures of phases in the QCD phase diagram can have consequences on signals of the existence of quark matter expected to be created in heavy-ion collisions, as well as supernova explosions and neutron-star mergers.

    nucl-thastro-ph.HEPoS(2018)·0 citations
  9. 09

    Drag Induced Radiation and Multi-Stage Effects in Heavy-Flavor Energy Loss

    Shanshan Cao🇺🇸 · Abhijit Majumder🇺🇸 · Guang-You Qin🇨🇳 · Chun Shen🇺🇸

    It is argued that heavy-quarks traversing a Quark Gluon Plasma, undergo a multi-stage modification process, similar to the case of light flavors. Such an approach is applied to heavy-quark energy loss, which includes a rare-scattering, multiple emission formalism at momenta large compared to the mass (sensitive only to the transverse diffusion coefficient ), and a single scattering induced emission formalism (Gunion-Bertsch) at momenta comparable to the mass of the quark [sensitive to , and the longitudinal drag () and diffusion () coefficients]. The application of such a multi-stage approach within a 2+1D viscous fluid-dynamical simulation leads to simultaneous agreement with experimental data for the nuclear modification factor of both and mesons, as measured by the CMS collaboration at the LHC. The extracted transport coefficients are found to be consistent with those for light flavors.

    nucl-thhep-phnucl-exPLB(2019)·22 citations

Affiliations

first authorsco-authorsvia INSPIRE