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1.
Based on Dyson-Schwinger equations in “rainbow“ approximation, fully dressed confining quark propagator is obtained, and then the masses of light quarks (mu, md, and ms) are derived from the fully dressed confining quark propagator. At the same time, the local and non-local quark vacuum condensates as well as the quark-gluon mixed condensate are also predicted. Furthermore, the quark masses are also deduced from the Gell-Mann-Oakes-Renner relation and chiral perturbative theory. The results from different methods are consistent with each other. 相似文献
2.
研究夸克的质量是QCD研究中的一个非常重要问题。因为, 夸克质量是标准模型的基本输入参数, 准确地确定这些参数无论对于唯象的应用还是对于理论的应用都是极其重要的。基于参数化的完全穿衣服的夸克传播子, 研究了自能函数和夸克的动力学质量。理论预言了夸克质量和自能函数, 其结果与文献中的经验值相符合, 也与Dyson Schwinger方程解一致。反过来这也说明了参数化的夸克传播子是成功和可靠的。Study of mass of quark is one of the most important issues in the investigation of QCD. Because masses of quarks are fundamental QCD input parameters of standard Model, and an accurate determination of these parameters is extremely important for both phenomenological and theoretical applications. Based on the parameterized fully dressed quark propagator proposed by us, the theoretical predictions of the masses of quarks are predicted in this short note. The effective quark mass is defined by the scalar self energy function Bf(p2) and vector self energy function Af(p2). The results of our calculations are in agreement with the empirical values used widely in literature and also show that the parameterized form of quark propagator is an applicable and reliable approximation. 相似文献
3.
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
4.
Based on the fully dressed confining quark propagator, the pion decay constant fπ, local quark vacuum condensate, and the
masses of light quarks and in-medium Goldstone bosons are investigated. The pion decay constant fπ is predicted and compared with its value of experimental measurement. A great
agreement is obtained. With the predicted fπ and values of
Goldstone boson masses measured by experiments in free configuration the current masses of light quarks and the masses of in-medium Goldstone bosons are obtained. 相似文献
5.
Based on an extensive study of the Dyson-Schwinger equations for a fully
dressed quark propagator in the “rainbow” approximation, a parametrized form of the
quark propagator is suggested. The corresponding quark self-energy
Σf and the
structure of non-local quark vacuum condensate <0|:\bar{q}(x)q(0):|0>
are investigated. The algebraic form of the quark propagator proposed in this work describes a confining quark propagation, and is quite convenient
to be used in any numerical calculations. 相似文献
6.
Based on the Dyson-Schwinger equations of QCD in the "rainbow" approximation, the fully dressed quarkpropagator Sf(p) is investigated, and then an algebraic parametrization form of the propagator is obtained as a solutionof the equations. The dressed quark amplitudes Af and Bf built up the fully dressed quark propagator and the dynamicalrunning masses Mf defined by Af and Bf for light quarks u, d and s are calculated, respectively. Using the predictedrunning masses Mf, quark condensates <0|q(0)q(0)|0> = -(0.255 GeV)a for u, d quarks, and <0|s s|0> = 0.8<0|q(0)q(0)]0)for s quark, and experimental pion decay constant fπ = 0.093 GeV, the masses of Goldstone bosons K, π, and η are alsoevaluated. The numerical results show that the masses of quarks are dependent on their momentum p2. The fully dressedquark amplitudes Af and Bf have correct behaviors which can be used for many purposes in our future researches onnonperturbative QCD. 相似文献
7.
According to extensive study of the Dyson-Schwinger equations for a fully dressed quark propagator in the "rainbow" approximation with an effective gluon propagator, a parametrized fully dressed confining quark propagator is suggested in this paper. The parametrized quark propagator describes a confined quark propagation in hadron, and is analytic everywhere in complex p2-plane and has no Lehmann representation. The vector and scalar self-energy functions [1 - Af(p2)] and [Bf(p2) - mf], dynamically running effective mass of quark Mf(p2) and the structure of non-local quark vacuum condensates as well as local quark vacuum condensates are predicted by use of the parametrized quark propagator. The results are compatible with other theoretical calculations. 相似文献
8.
ZHU Ji-Zhen ZHOU Li-Juan MA Wei-Xing 《理论物理通讯》2005,44(7)
Based on an extensively study of the Dyson-Schwinger equations for a fully dressed quark propagator in the “rainbow“ approximation, a parametrized fully dressed quark propagator is proposed in this paper. The parametrized propagator describes a confining quark propagator in hadron since it is analytic everywhere in complex p2-plane and has no Lemmann representation. The validity of the new propagator is discussed by comparing its predictions on selfenergy functions Af(p2), Bf(p2) and effective mass Mf(p2) of quark with flavor f to their corresponding theoretical results produced by Dyson-Schwinger equations. Our comparison shows that the parametrized quark propagator is a good approximation to the fully dressed quark propagator given by the solutions of Dyson-Schwinger equations in the rainbow approximation and is convenient to use in any theoretical calculations. 相似文献
9.
10.
ZHUJi-Zhen ZHOULi-Juan MAWei-Xing 《理论物理通讯》2005,44(1):117-122
Based on an extensively study of the Dyson-Schwinger equations for a fully dressed quark propagator in the “rainbow”approximation, a parametrized fully dressed quark propagator is proposed in this paper. The parametrized propagator describes a confining quark propagator in hadron since it is analytic everywhere in complex p2-plane and has no Lemmann representation. The validity of the new propagator is discussed by comparing its predictions on selfenergy functions A/(p2), Bl(p2) and effective mass M$(p2) of quark with flavor f to their corresponding theoretical results produced by Dyson-Schwinger equations. Our comparison shows that the parametrized quark propagator is a good approximation to the fully dressed quark propagator given by the solutions of Dyson-Schwinger equations in the rainbow approximation and is convenient to use in any theoretical calculations. 相似文献
11.
HE Xiao-Rong ZHOU Li-Juan Wei-Xing 《理论物理通讯》2005,44(4):670-674
Based on Dyson Schwinger Equations (DSEs) in the “rainbow” approximation, the dependence of quark effective mass on gluon propagator is investigated by use of three different phenomenological gluon propagators with two parameters, the strength parameter x and range parameter △. Our theoretical calculations for the quark effective mass Mf(p^2), defined by the self-energy functions Af(p^2) and Bi(p%2) of the DSEs, show that the dynamically running quark effective mass is strongly dependent on gluon propagator. Therefore, because gluon propagator is completely unknown, the quark effective mass cannot be exactly determined theoretically. 相似文献
12.
HE Xiao-Rong ZHOU Li-Juan MA Wei-Xing 《理论物理通讯》2005,44(10)
Based on Dyson-Schwinger Equations (DSEs) in the “rainbow“ approximation, the dependence of quark effective mass on gluon propagator is investigated by use of three different phenomenological gluon propagators with two parameters, the strength parameter x and range parameter △. Our theoretical calculations for the quark effective mass Mf(p2), defined by the self-energy functions Af(p2) and Bf(p2) of the DSEs, show that the dynamically running quark effective mass is strongly dependent on gluon propagator. Therefore, because gluon propagator is completely unknown,the quark effective mass cannot be exactly determined theoretically. 相似文献
13.
Based on the Dyson-Schwinger equations in rainbow approximation for quark propagator with an effective gluon propagator, and on the parametrized fully dressed quark propagator proposed by us, the unknown Gasser-Leutwyler coefficients of the chiral Lagrangian for pseudoscalar Goldstone bosons, Li, are predicted respectively. The predicted values of Li in the two different ways are not only in reasonable agreement each other but also in agreement with empirical values used widely in literature and the values predicted by many other theoretical models with QCD characteristics. The compatible results of Gasser-Leutwyler coefficients predicted by our parameterized quark propagator,in turn, clearly verify its extensive validity. 相似文献
14.
ZHOU Li-Juan WU Qing PAN Ji-Huan MENG Cheng-Ju MA Wei-Xing LI Xi-Guo 《理论物理通讯》2006,46(1):101-108
Based on the Dyson-Schwinger equations in raAnbow approximation for quark propagator with an effective gluon propagator, and on the parametrized fully dressed quark propagator proposed by us, the unknown GasserLeutwyler coeiticients of the chiral Lagrangian for pseudoscalar Goldstone bosons, Li, are predicted respectively. The predicted values of Li in the two different ways are not only in reasonable agreement each other but also in agreement with empirical values used widely in literature and the values predicted by many other theoretical models with QCD characteristics. The compatible results of Gasser-Leutwyler coefficients predicted by our parameterized quark propagator, in turn, clearly verify its extensive validity. 相似文献
15.
16.
17.
Based on the Dyson-Schwinger Equations (DSEs) of QCD in the “rainbow” approximation, the fully dressed quark propagator S
f
(p) is investigated, and then an algebraic parametrization form of the propagator is obtained as a solution of the equations.
The dressed quark amplitudes A
f
and B
f
which built up the fully dressed quark propagator, and the dynamical running masses M
f
, which is defined by A
f
and B
f
for light quarks u, d and s, are calculated, respectively. Using the predicted current masses m
f
, quark local vacuum condensates, and our predicted value of pion decay constant, the masses of Goldstone bosons K, π and η and their in-medium values are also evaluated. Our predictions fit to data and to many other different calculations quite
well. The numerical results show that the mass of quark is dependent of its momentum p
2. The fully dressed quark amplitudes A
f
and B
f
have correct behaviors and can be used for many purposes in our future researches on non-perturbative QCD.
相似文献
18.
LIU Da-Qing 《理论物理通讯》2006,46(12)
We show an interesting empirical formula of quark masses here, which is obtained by implementing the least squares fit. In this formula the measured QCD coupling is almost a “best fitting coupling“. 相似文献
19.
LIU Da-Qing 《理论物理通讯》2006,46(6):1027-1030
We show an interesting empirical formula of quark masses here, which is obtained by implementing the east squares fit. In this formula the measured QCD coupling is almost a "best fitting coupling". 相似文献
20.
用改进的Wilson夸克格点哈密顿量和变分法研究2维SU(NC)规范场中夸克真空凝聚〈ψψ〉与夸克质量mq和Wilson参数r的依赖关系. 结果表明: 对于给定的r, 当NC=2,3,4,5,6,7,时,
〈ψψ〉suba/(gNC3/2)的值随mq的增大而减小. 对于较大的NC(如NC>3), 当mq很小时, 〈ψψ〉suba(gNC3/2)对r的依赖性很小, 但随着mq的增大, 〈ψψ〉suba/(gNC3/2)对r的依赖性增大, 且〈ψψ〉suba/(gNC3/2)的值随r的增大而增大; 特别是, 当mq→0时, 本文的格点结果与Zhitnitsky的连续理论分析结果(在弱耦合相中)很好地一致, 这意味着本文在mq≠0时所得到的结果是可靠的. 相似文献