Nuclear Theory·nucl-th

Friday·April 8, 2016

6 papers—2 primary·4 cross-listed

01
Couplings between the $ρ$ and $D$ - and $D^{*}$ -mesons
Bruno El-Bennich🇧🇷 · M. Ali Paracha🇵🇰 · Craig D. Roberts🇺🇸 · Eduardo Rojas🇨🇴
We compute couplings between the $ρ$ -meson and $D$ - and $D^{*}$ -mesons - $D^{(*)} ρ D^{(*)}$ - that are relevant to phenomenological meson-exchange models used to analyse nucleon- $D$ -meson scattering and explore the possibility of exotic charmed nuclei. Our framework is built from elements constrained by Dyson-Schwinger equation studies in QCD, and therefore expresses a consistent, simultaneous description of light- and heavy-quarks and the states they constitute, We find that all interactions, including the three independent $D^{*} ρ D^{*}$ couplings, differ markedly amongst themselves in strength and also in range, as measured by their evolution with $ρ$ -meson virtuality. As a consequence, it appears that no single coupling strength or parametrization can realistically be employed in the study of interactions between $D^{(*)}$ -mesons and matter.
nucl-thhep-exhep-lathep-ph+1PRD(2017)·21 citations
02
Constraining the equation of state of nuclear matter from competition of fusion and quasi-fission in the reactions leading to production of the superheavy elements
Martin Veselsky · Jozef Klimo · Yu-Gang Ma · Georgios A. Souliotis
The mechanism of fusion hindrance, an effect preventing the synthesis of superheavy elements in the reactions of cold and hot fusion, is investigated using the Boltzmann-Uehling-Uhlenbeck equation, where Coulomb interaction is introduced. A strong sensitivity is observed both to the modulus of incompressibility of symmetric nuclear matter, controlling the competition of surface tension and Coulomb repulsion, and to the stiffness of the density-dependence of symmetry energy, influencing the formation of the neck prior to scission. The experimental fusion probabilities were for the first time used to derive constraints on the nuclear equation of state. A strict constraint on the modulus of incompressibility of nuclear matter $K_{0} = 240 - 260$ MeV is obtained while the stiff density-dependences of the symmetry energy ( $γ > 1.$ ) are rejected.
nucl-thnucl-exPRC(2016)·12 citations
03
Eta and kaon production in a chiral quark model
Bojan Golli🇸🇮 · Simon Širca🇸🇮
We apply a coupled-channel formalism incorporating quasi-bound quark-model states to calculate pion scattering into eta N, K Lambda and K Sigma channels, as well eta p, eta n, K+Lambda, and K0Sigma+ photo-production processes. The meson-baryon and photon-baryon vertices are determined in a SU(3) version of the Cloudy Bag Model. Our model predicts sizable amplitudes in the P11, P13, P33 and S11 partial waves in agreement with the latest MAID isobar model and the recent partial-wave analyses of the Bonn-Gatchina group. We are able to give a quark-model explanation for the apparent resonance at 1685 MeV in the eta n channel.
↳ hep-phnucl-thEPJA(2016)·13 citations
04
Neutron star radii and crusts: uncertainties and unified equations of state
M. Fortin🇵🇱 · C. Providencia🇵🇹 · A. R. Raduta🇷🇴 · F. Gulminelli🇫🇷 · J. L Zdunik🇵🇱 · P. Haensel🇵🇱 · M. Bejger🇵🇱
The uncertainties in neutron star (NS) radii and crust properties due to our limited knowledge of the equation of state (EOS) are quantitatively analysed. We first demonstrate the importance of a unified microscopic description for the different baryonic densities of the star. If the pressure functional is obtained matching a crust and a core EOS based on models with different properties at nuclear matter saturation, the uncertainties can be as large as $\sim 30%$ for the crust thickness and $4%$ for the radius. Necessary conditions for causal and thermodynamically consistent matchings between the core and the crust are formulated and their consequences examined. A large set of unified EOS for purely nucleonic matter is obtained based on 24 Skyrme interactions and 9 relativistic mean-field nuclear parametrizations. In addition, for relativistic models 17 EOS including a transition to hyperonic matter at high density are presented. All these EOS have in common the property of describing a $2 M_{⊙}$ star and of being causal within stable NS. A span of $\sim 3$ km and $\sim 4$ km is obtained for the radius of, respectively, $1.0 M_{⊙}$ and $2.0 M_{⊙}$ star. Applying a set of nine further constraints from experiment and ab-initio calculations the uncertainty is reduced to $\sim 1$ km and $2$ km, respectively. These residual uncertainties reflect lack of constraints at large densities and insufficient information on the density dependence of the EOS near the nuclear matter saturation point. The most important parameter to be constrained is shown to be the symmetry energy slope $L$ which exhibits a linear correlation with the stellar radius, particularly for masses $\sim 1.0 M_{⊙}$ . Potential constraints on $L$ , the NS radius and the EOS from observations of thermal states of NS are also discussed. [Abriged]
↳ astro-ph.SRastro-ph.HEnucl-thPRC(2016)·362 citations
05
Angular distributions in $J / ψ \to p p ˉ π^{0} (η)$ decays
V. F. Dmitriev🇷🇺 · A. I. Milstein🇷🇺 · S. G. Salnikov🇷🇺
The differential decay rates of the processes $J / ψ \to p p ˉ π^{0}$ and $J / ψ \to p p ˉ η$ close to the $p p ˉ$ threshold are calculated with the help of the $N N ˉ$ optical potential. The same calculations are made for the decays of $ψ (2 S)$ . We use the potential which has been suggested to fit the cross sections of $N N ˉ$ scattering together with $N N ˉ$ and six pion production in $e^{+} e^{-}$ annihilation close to the $p p ˉ$ threshold. The $p p ˉ$ invariant mass spectra is in agreement with the available experimental data. The anisotropy of the angular distributions, which appears due to the tensor forces in the $N N ˉ$ interaction, is predicted close to the $p p ˉ$ threshold. This anisotropy is large enough to be investigated experimentally. Such measurements would allow one to check the accuracy of the model of $N N ˉ$ interaction.
↳ hep-phnucl-thPLB(2016)·9 citations
06
Opportunities for nuclear reaction studies at future facilities
Martin Veselsky · Jozef Klimo · Nikoleta Vujisicova · Georgios A. Souliotis
Opportunities for investigations of nuclear reactions at the future nuclear physics facilities such as radioactive ion beam facilities and high-power laser facilities are considered. Post-accelerated radioactive ion beams offer possibilities for study of the role of isospin asymmetry in the reaction mechanisms at various beam energies. Fission barrier heights of neutron-deficient nuclei can be directly determined at low energies. Post-accelerated radioactive ion beams, specifically at the future facilities such as HIE-ISOLDE, SPIRAL-2 or RAON-RISP can be also considered as a candidate for production of very neutron-rich nuclei via mechanism of multi-nucleon transfer. High-power laser facilities such as ELI-NP offer possibilities for nuclear reaction studies with beams of unprecedented properties. Specific cases such as ternary reactions or even production of super-heavy elements are considered.
↳ nucl-exnucl-thAdv.Nucl.Phys.(2019)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Couplings between the ρ and D- and D∗-mesons

Constraining the equation of state of nuclear matter from competition of fusion and quasi-fission in the reactions leading to production of the superheavy elements

Eta and kaon production in a chiral quark model

Neutron star radii and crusts: uncertainties and unified equations of state

Angular distributions in J/ψ→ppˉ​π0(η) decays

Opportunities for nuclear reaction studies at future facilities

Affiliations

Couplings between the $ρ$ and $D$ - and $D^{*}$ -mesons

Angular distributions in $J / ψ \to p p ˉ π^{0} (η)$ decays