ترغب بنشر مسار تعليمي؟ اضغط هنا

Improved quark mass density- dependent model with quark-sigma meson and quark-omega meson couplings

109   0   0.0 ( 0 )
 نشر من قبل Chen Wu
 تاريخ النشر 2007
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

An improved quark mass density- dependent model with the non-linear scalar sigma field and the $omega$-meson field is presented. We show that the present model can describe saturation properties, the equation of state, the compressibility and the effective nuclear mass of nuclear matter under mean field approximation successfully. The comparison of the present model and the quark-meson coupling model is addressed.



قيم البحث

اقرأ أيضاً

350 - Chen Wu , Ru-Keng Su 2008
By using the finite temperature quantum field theory, we calculate the finite temperature effective potential and extend the improved quark mass density-dependent model to finite temperature. It is shown that this model can not only describe the satu ration properties of nuclear matter, but also explain the quark deconfinement phase transition successfully. The critical temperature is given and the effect of $omega$- meson is addressed.
Short-range quark-quark correlations are introduced into the quark-meson coupling (QMC) model phenomenologically. We study the effect of the correlations on the structure of the nucleon in dense nuclear matter. With the addition of correlations, the saturation curve for symmetric nuclear matter is much improved at high density.
The improved quark mass density- dependent model, which has been successfully used to describe the properties of both finite nuclei and bulk nuclear matter, is extended to include the strange quark. The parameters of the model are determined by the s aturation properties of bulk matter. Then the given parameter set is employed to investigate both the properties of strange hadronic matter and those of $Lambda$ hypernuclei. Bulk strange hadronic matter consisting of nucleons, $Lambda$- hyperons and $Xi$- hyperons is studied under mean-field approximation. Among others, density dependence of the effective baryon mass, saturation properties and stability of the physical system are discussed. For single-$Lambda$ hypernuclei, single particle energies of $Lambda$ hyperon is evaluated. In particular, it is found that the present model produces a small spin-orbit interaction, which is in agreement with the experimental observations. The above results show that the present model can consistently describe the properties of strange hadronic matter, as well as those of single $Lambda$ hypernuclei within an uniform parameterization.
The momemtum dependence of the off-shell $rho$-$omega$ mixing amplitude is calculated through a two-quark loop diagram, using non-perturbative meson-quark vertex functions for the $rho$ and $omega$ mesons, as well as non-perturbative quark propagator s. Both these quantities are generated self-consistently through an interlinked BSE-cum-SDE approach with a 3D support for the BSE kernel with two basic constants which are pre- checked against a wide cross section of both meson and baryon spectra within a common structural framework for their respective 3D BSEs. With this pre-calibration, the on-shell strength works out at -2.434$delta(m_q^2)$ in units of the change in constituent mass squared, which is consistent with the $e^+e^-$ to $pi^+pi^-$ data for a u-d mass difference of ~4 MeV ,while the relative off-shell strength (0.99 $pm$ 0.01) lies midway between quark-loop and QCD-SR results. We also calculate the photon-mediated $rho$-$omega$ propagator whose off-shell structure has an additional pole at $q^2$=0. The implications of these results vis-a-vis related investigations are discussed.
We investigate quark potential by considering meson exchanges in the two flavor Nambu--Jona-Lasinio model at finite temperature and density. There are two kinds of oscillations in the chiral restoration phase, one is the Friedel oscillation due to th e sharp quark Fermi surface at high density, and the other is the Yukawa oscillation driven by the complex meson poles at high temperature. The quark-meson plasma is strongly coupled in the temperature region $1le T/T_c lesssim 3$ with $T_c$ being the critical temperature of chiral phase transition. The maximum coupling in this region is located at the critical point.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا