Nuclear Theory·nucl-th

Monday·November 7, 2016

9 papers—5 primary·4 cross-listed

06
Heavy meson spectroscopy under strong magnetic field
Tetsuya Yoshida🇯🇵 · Kei Suzuki🇰🇷
Spectra of the neutral heavy mesons, $η_{c} (1 S, 2 S)$ , $J / ψ$ , $ψ (2 S)$ , $η_{b} (1 S, 2 S, 3 S)$ , $Υ (1 S, 2 S, 3 S)$ , $D$ , $D^{*}$ , $B$ , $B^{*}$ , $B_{s}$ and $B_{s}^{*}$ , in a homogeneous magnetic field are analyzed in a potential model of constituent quarks. To obtain anisotropic wave functions and the corresponding eigenvalues, the cylindrical Gaussian expansion method is applied, where the wave functions for transverse and longitudinal directions in the cylindrical coordinate are expanded by the Gaussian bases separately. Energy level structures in the wide range of magnetic fields are obtained and the deformation of the wave functions is shown, which reflects effects of the spin mixing, the Zeeman splitting and quark Landau levels. The contribution from the magnetic catalysis in heavy-light mesons is discussed as a change of the light constituent quark mass.
↳ hep-phhep-latnucl-thPRD(2016)·67 citations
07
Role of $σ$ exchange in the $γ p \to ϕp$ process and scaling with the $f_{1}$ axial vector meson from a Reggeized model
Byung-Geel Yu🇰🇷 · Hungchong Kim🇰🇷 · Kook-Jin Kong🇰🇷
We investigate the role driven by the scalar meson $σ$ exchange in the photoproduction of the vector meson $ϕ$ (1020) off a proton by using a Reggeized model. Based on the $π^{0} (135) + σ (500) + f_{2} (1270)$ +Pomeron exchanges, we demonstrate that the $σ$ exchange plays the role to reproduce the bump structure at the forward angle in the differential cross section as well as the peaking behavior in the total cross section observed in the CLAS Collaboration. We also discuss the possible observation of the scaled cross section $s^{7} d σ / d t$ at the production angle $θ = 9 0^{\circ}$ from the CLAS data. It is found that the axial vector meson $f_{1} (1285)$ exchange with the trajectory $α_{f_{1}} (t) = 0.028 t + 0.9 \pm 0.2$ arising from the axial anomaly of the QCD vacuum plays the role to clarify the scaling up to 5 GeV.
↳ hep-phnucl-thPRD(2017)·14 citations
08
Neutron star properties and the equation of state for its core
J. L. Zdunik · M. Fortin · P. Haensel
Few unified equations of state for neutron star matter where core and crust are described using the same nuclear model are available. However the use of non-unified equations of state with a simplified matching between the crust and the core has been shown to introduce uncertainties in the radius determination which can be larger than the expected precision of the next generation of X-ray satellites. We aim at eliminating the dependence of the radius and mass of neutron staron the detailed model for the crust and on the crust-core matching procedure. We solve the approximate equations of the hydrostatic equilibrium for the crust of neutron stars obtaining a precise formula for the radius which depends only on the core mass and radius, and on the baryon chemical potential at the core-crust interface and on the crust surface. For a fully accreted crust one needs additionally the value of the total deep crustal heating per one accreted nucleon. For typical neutron star masses the approximate approach allows to determine the neutron star radius with an error ~0.1% (~ 10 m, equivalent to a 1% inaccuracy in the crust thickness). The formalism applies to neutron stars with a catalyzed or a fully accreted crust. The difference in the neutron star radius between the two models is proportional to the total energy release due to deep crustal heating. For a given model of dense matter describing the neutron star core, the radius of a neutron star can be accurately determined independently of the crust model with a precision much better than the ~5% one expected from the next generation of X-ray satellites. This allows to circumvent the problem of the radius uncertainty which may arise when non-unified equations of state for the crust and the core are used.
↳ astro-ph.HEastro-ph.SRnucl-thAstron.Astrophys.(2017)·50 citations
09
Quark mass effects in quark number susceptibilities
Thorben Graf🇫🇷 · Peter Petreczky🇺🇸
The quark degrees of freedom of the QGP with special focus on mass effects are investigated. A next-to-leading-order perturbation theory approach with quark mass dependence is applied and compared to lattice QCD results.
↳ hep-phhep-latnucl-thJ.Phys.Conf.Ser.(2017)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

Heavy meson spectroscopy under strong magnetic field

Role of σ exchange in the γp→ϕp process and scaling with the f1​ axial vector meson from a Reggeized model

Neutron star properties and the equation of state for its core

Quark mass effects in quark number susceptibilities

Affiliations

Role of $σ$ exchange in the $γ p \to ϕp$ process and scaling with the $f_{1}$ axial vector meson from a Reggeized model