共查询到20条相似文献,搜索用时 0 毫秒
1.
SHI Yuan-Mei PING Jia-Lun 《理论物理通讯》2005,44(9)
The vector susceptibility is investigated numerically in the Dyson-Schwinger approach. The results agree with those obtained analytically previously by using a simple gluon propagator. 相似文献
2.
The pion and tensor vacuum susceptibilities are calculated in the
framework of the renormalizable Dyson-Schwinger equations. A comparison
with the results of other nonperturbative QCD approaches is given. 相似文献
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Using a nonlocal four-quark condensate in the framework of the modified global colour symmetry model, we determine the tensor vacuum susceptibility needed in the QCD sum rule external field method for the coupling of tensor current to hadron and compare it with the previous estimations. 相似文献
5.
ZHOU Li-Juan WU Qing MA Wei-Xing 《理论物理通讯》2008,50(7):161-174
We study vacuum of QCD in this work. The structure of non-local quark vacuum condensate, values of various local quark and gluon vacuum condensates, quark-gluon mixed vacuum condensate, quark and gluon virtuality in QCD vacuum state, quark dynamical mass and susceptibility of QCD vacuum state to external field are predicted by use of the solutions of Dyson-Schwinger equations in "rainbow" approximation with a modeling gluon propagator and three different sets of quark-quark interaction parameters. Our theoretical predictions are in good agreement with the correspondent empirical values used widely in literature, and many other theoretical calculations. The quark propagator and self-energy functions are also obtained from the numerical solutions of Dyson Schwinger equations. This work is centrally important for studying non-perturbative QCD, and has many important applications both in particle and nuclear physics. 相似文献
6.
We study vacuum of QCD in this work. The structure of non-local
quark vacuum condensate, values of various local quark and gluon
vacuum condensates, quark-gluon mixed vacuum condensate, quark and
gluon virtuality in QCD vacuum state, quark dynamical mass and
susceptibility of QCD vacuum state to external field are predicted by use of the solutions of Dyson-Schwinger equations in “rainbow”
approximation with a modeling gluon propagator and three different
sets of quark-quark interaction parameters. Our theoretical
predictions are in good agreement with the correspondent empirical
values used widely in literature, and many other theoretical
calculations. The quark propagator and self-energy functions are
also obtained from the numerical solutions of Dyson-Schwinger
equations. This work is centrally important for studying
non-perturbative QCD, and has many important applications both in
particle and nuclear physics. 相似文献
7.
.A new approach for calculating vacuum susceptibilities from an effective quark-quark interaction model is derived. As a special case, the vector vacuum susceptibility is calculated. A comparison with the results of the previous approaches is given. 相似文献
8.
ZONGHong-Shi QIShi CHENWei WUXiao-Hua 《理论物理通讯》2003,40(6):675-680
A new approach for calculating vacuum susceptibilities from an effective quark-quark interaction model is derived. As a special case, the vector vacuum susceptibility is calculated. A comparison with the results of the previous approaches is given. 相似文献
10.
ZHOU Li-Juan PING Rong-Gang MA Wei-Xing 《理论物理通讯》2004,42(12)
Based on Dyson-Schwinger equations (DSEs) in “rainbow“ approximation, the dynamically running mass of light quark and QCD vacuum condensate are investigated. The structure of non-local quark vacuum condensate, the values of local vacuum condensate of quarks and quark-gluon mixture, and dynamical transition of quark mass from current quark to constituent quark are illustrated. At the same time, according to the knowledge and experience learned from an extensive study of the solutions of DSEs, a parameterized form of confining quark propagator is suggested for a practical use. The new parameterized form of quark propagator is analytic everywhere in the finite complex p2-plane and has no Lehmann representation. The predictions for p2-dependence of effective quark masses, Mf(p2), defined by the self-energy functions Af(p2) and Bf(p2), both from the numerical solutions of DSEs and from its parameterized form, are shown dynamically. Our conclusion is that all numerical results are consistent with empirical values used in QCD sum rules and lattice QCD calculations. For a qualitative study, the parameterized form is a sufficiently good approximation to confining quark propagator. 相似文献
11.
HU Fei JIANG Yu FENG Hong-Tao SUN Wei-Min ZONG Hong-Shi 《理论物理通讯》2008,49(3):703-706
Based on the study of the linear response of the fermion propagator to the presence of an external scalar field, a new method for calculating the staggered spin susceptibility in QED3 is presented, in which the influence of the full vertex function is included. The numerical values of the staggered spin susceptibility are calculated within the framework of the rainbow-ladder approximation of the Dyson-Schwinger approach. A comparison between the result calculated using the full vertex and that using the bare vertex is given. 相似文献
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13.
Gluon propagator is investigated for pure Yang-Mills SU(3) gauge theory in field-strength approach. It isfound that instantohs provide a homogeneous solid-like medium background which generates finite nonzero momentumgluon propagator and gluon receives effective mass. 相似文献
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15.
We study the properties of QCD vacuum state in this paper. The values of various local quark vacuum condensates, quark-gluon mixed vacuum condensates, and the structure of non-local quark vacuum condensate are predicted by the solution of Dyson-Schwinger Equations in "rainbow" approximation with three sets of different parameters for effective gluon propagator. The light quark virtuality is also obtained in a consistent way. Our all theoretical results here are in good agreement with the empirical values used widely in literature and many other theoretical calculations. 相似文献
16.
WU Kong-Ping SHI Yuan-Mei SUN Wei-Min PING Jia-Lun ZONG Hong-Shi 《理论物理通讯》2008,49(1):189-192
In quantum chromodynamics (QCD), the scalar susceptibility represents the modification of the quark condensate, to a small perturbation of the parameter responsible for the explicit breaking of the symmetry, i.e., the current quark mass. By studying the linear response of the dressed quark propagator to the presence of a nonzero quark mass, we derive a model-independent formula for the scalar susceptibility, which contains the dressed quark propagator G(p) and the dressed scalar vertex F(p, 0). The numerical values of the scalar susceptibility Xs are calculated within the framework of the rainbow-ladder approximation of the Dyson-Schwinger approach by employing two typical forms of model gluon propagator. 相似文献
17.
ZHOU Li-Juan MENG Cheng-Ju PAN Ji-Huan LIU Bao-Rong MA Wei-Xing 《理论物理通讯》2008,49(3):717-722
Based on the parameterized fully dressed quark propagator proposed by us, the tensor susceptibilities of QCD vacuum and quark vacuum condensates are investigated. Our predicted values of the tensor susceptibilities are in agreement with those predicted by many other theoretical models with QCD feature. The results also show that the tensor susceptibility of QCD vacuum strongly depends on flavor of quark but not sensitive to variation of quark vacuum condensates. However, the quark vacuum condensate is very sensitive to the change of cut-off-parameter μ^2 of the integration, that is, it depends on the separation point of perturbative and non-perturbative QCD region. The successful predictions clearly indicate the extensive validity of our parameterized fully dressed quark propagator used here. 相似文献
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WANG Jing SHI Yuan-Mei HOU Feng-Yao SUN Wei-Min ZONG Hong-Shi PING Jia-Lun 《理论物理通讯》2008,49(4):1001-1003
We do a numerical calculation on the quark-loop effects on the dressed gluon propagator in the chiral limit. It is found that the quark-loop effects on the dressed gluon propagator are significant in solving the quark propagator in the rainbow approximation of the Dyson-Schwinger equation. The approach we used here is quite general and can also be used to calculate both the chemical potential and current quark mass dependence of the dressed gluon propagator. 相似文献
20.
Gluon propagator is investigated for pure Yang-Mills SU(3) gauge
theory in field-strength approach. It is found that instantons
provide a homogeneous solid-like medium background which generates
finite nonzero momentum gluon propagator and gluon receives
effective mass. 相似文献