PaperPanorama

Nuclear Theory·nucl-th

Tuesday·January 1, 2019

14 papers5 primary·9 cross-listed

  1. 01

    The puzzle of complete fusion suppression in weakly-bound nuclei: a Trojan Horse effect?

    Jin Lei🇺🇸 · Antonio M. Moro🇪🇸

    Experimental studies of nuclear collisions involving light weakly-bound nuclei show a systematic suppression of the complete fusion cross section by 30\% with respect to the expectation for tightly bound nuclei, at energies above the Coulomb barrier. Although it is widely accepted that the phenomenon is related to the weak binding of these nuclei, the origin of this suppression is not fully understood. In here, we present a novel approach that provides the complete fusion for weakly bound nuclei and relates its suppression to the competition between the different mechanisms contributing to the reaction cross section. The method is applied to the Li+Bi reactions, where we find that the suppression of complete fusion is mostly caused by the flux associated with non-elastic breakup modes, such as the partial capture of the projectile (incomplete fusion), whereas the elastic breakup mode is found to play a minor role. Finally, we demonstrate that the large yields observed in these reactions can be naturally explained as a consequence of a {\it Trojan Horse} mechanism.

    nucl-thPRL(2019)·55 citations
  2. 02

    Nuclear effects in the deuteron in the resonance and deep-inelastic scattering region

    S.A. Kulagin🇷🇺

    We discuss a hybrid model of the proton and neutron inelastic structure functions which incorporates both the partonic and the nucleon resonance structures and applicable in a wide region of the invariant mass of produced hadronic states. Focusing at the typical kinematics of JLab experiments we compute the deuteron structure functions and demonstrate good performance of the model against data. We perform systematic study of the ratios and for both, the deep-inelastic and the resonance, region in the context of recent measurements of BoNuS experiment at Jefferson Lab.

    nucl-thPhys.Part.Nucl.(2019)·5 citations
  3. 03

    Nuclear response in a finite-temperature relativistic framework

    Elena Litvinova🇺🇸 · Herlik Wibowo🇺🇸

    A thermal extension of the relativistic nuclear field theory is formulated for the nuclear response. The Bethe-Salpeter equation (BSE) with the time-dependent kernel for the particle-hole response is treated within the Matsubara Green's function formalism. We show that, with the help of a temperature-dependent projection operator on the subspace of the imaginary time (time blocking), it is possible to reduce the BSE for the nuclear response function to a single frequency variable equation also at finite temperature. The approach is implemented self-consistently in the framework of quantum hadrodynamics based on the meson-nucleon Lagrangian. The method is applied to the monopole, dipole and quadrupole response of Ca and to the dipole response of the tin isotopes Sn, in particular, to a study of the evolution of nuclear collective oscillations with temperature. The article is dedicated to the memory of Pier Francesco Bortignon and devoted to the developments related to his pioneering ideas.

    nucl-thnucl-exEPJA(2019)·21 citations
  4. 04

    A unified quark-nuclear matter equation of state from the cluster virial expansion within the generalized Beth-Uhlenbeck approach

    Niels-Uwe Friedrich Bastian🇵🇱 · David Bernhard Blaschke🇵🇱

    We consider a cluster expansion for strongly correlated quark matter where the clusters are baryons with spectral properties that are described within the generalized Beth-Uhlenbeck approach by a medium dependent phase shift. We employ a simple ansatz for the phase shift which fulfils the Levinson theorem by describing an on-shell bound state with an effective mass and models the continuum by an anti-bound state located at the mass of the three-quark threshold. The quark and baryon interactions are accounted for by the coupling to scalar and vector meson mean fields modelled by density functionals. At increasing density and temperature, due to the different medium-dependence of quark and baryon masses, the Mott dissociation of baryons occurs and the nuclear cluster contributions to the thermodynamics vanish. It is demonstrated on this simple example that this unified approach to quark-nuclear matter is capable of describing crossover as well as first order phase transition behaviour in the phase diagram with a critical endpoint. Changing the meson mean field, the case of a "crossover all over" in the phase diagram is also obtained.

    nucl-thEPJA(2021)·14 citations
  5. 05

    Hybrid equation of state with pasta phases and third family of compact stars

    K. Maslov🇷🇺 · N. Yasutake🇯🇵 · A. Ayriyan🇷🇺 · D. Blaschke🇵🇱 · H. Grigorian🇷🇺 · T. Maruyama🇯🇵 · T. Tatsumi🇯🇵 · D. N. Voskresensky🇷🇺

    The effect of pasta phases on the quark-hadron phase transition is investigated for a set of relativistic mean-field equations of state for both hadron and quark matter. The results of the full numerical solution with pasta phases are compared with those of an interpolating construction used in previous works, for which we demonstrate an adequate description of the numerical results. A one-to-one mapping of the free parameter of the construction to the physical surface tension of the quark-hadron interface is obtained for which a fit formula is given. For each pair of quark and hadron matter models the critical value of the surface tension is determined, above which the phase transition becomes close to the Maxwell construction. This result agrees well with earlier theoretical estimates. The study is extended to neutron star matter in beta equilibrium with electrons and muons and is applied to investigate the effect of pasta phases on the structure of hybrid compact stars and the robustness of a possible third family solution.

    nucl-thastro-ph.HEhep-phPRC(2019)·78 citations

Affiliations

first authorsco-authorsvia INSPIRE