Ma Wei-Xing

High Energy bar pp and pp Elastic Scatterings in QCD Inspired Model

We propose QCD inspired model to calculate p and pp elastic scatterings at high energies in this paper. A calculation for total cross section of p and pp is performed in which the contributions from gluon-gluon, quark-quark, and gluon-quark interactions are included. Our results show that the QCD inspired model gives a perfect fit to experimental data of total cross section both for p and pp elastic scatterings at the whole energy region where experimental data existed at FNAL and CERN.

Gluonic Origin and Glueball Nature of Pomeron

The Pomeron-nucleon coupling vertex is theoretically derived from the fundamental theory of strong interaction QCD. The empirical vertex βγμ F1 ( t) used commonly in diffractive processes with a coupling strength β =6.0 GeV-1 is initially obtained from QCD theoretically. Our study not only reproduces the Pomeron-nucleon coupling from QCD but also clearly shows the gluonic origin and glueball nature of Pomeron, which is a longstanding puzzle.From this investigation, we claim that Pomeron can be regarded as a Reggeized tensor glueball ξ(2230) with quantum numbers of IGJPC = 0+2++. Since the tensor glueball ξ(2230) lies on the Pomeron trajectory αp(t = M2ξ) = 2, the longstanding puzzle that no physical particle lies on the Pomeron trajectory, αp(t) = 1.08 + 0.20 GeV-2 . t, seems to be solved.

Structure of Nonlocal Vacuum Condensate of Quarks

The Dyson-Schwinger formalism is used to derive a fully dressed quark propagator. By use of the derived form of the quark propagator, the structure of non-local quark vacuum condensate is studied, and the values of local quark vacuum condensate as well as quark gluon mixed condensate are calculated. The theoretical predictions are in good agreement with the empirical one used commonly in the literature.

Upsilon Photo-Production off Proton in QCD Inspired Model

Based on the generalized vector meson dominance model in QCD, we study photoproduction of vector meson γ off the proton by use of the QCD inspired model in which the contributions from quark-quark, gluon-gluon, and quark-gluon interference term to observable are taken into consideration. Calculations are performed for total cross section σtot, differential cross section dσ/dt, ratio of the real part to imaginary part of forward scattering amplitude ρ, and nuclear slop parameter function β. The mediators of interactions between projectiles (the quark and antiquark pair fluctuated from the real the photon) and the proton target (three-quark system) are the tensor Glueball and Odderon instead of using the usual Pomeron exchange. The theoretical predictions for σtot (s) are consistent with the experimental data within error bars of the data. The data for dσ/dt, ρ, and β are urgently needed.

Nuclear Slope Parameter of pp and bar pp Elastic Scattering in QCD Inspired Model

Based on the quark-gluon structure of nucleon and the possible existence of Odderon in strong interaction process due to gluon self-interaction, the elastic scatterings of pp and p at high energies are studied. The contributions from individual terms of quark-quark, gluon-gluon interactions, quark-gluon interference, and the Odderon terms to the nuclear slope parameter B(s) are analyzed. Our results show that the QCD inspired model gives a good fit to the LHC experimental data of the nuclear slope parameter.

Pion Decay Constant and Masses of Light Quarks and In-medium Goldstone Bosons

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.

Pomeron-Quark Coupling from Charge Conjugation Invariance

Based on the charge conjugation invariance and the vacuum property of the Pomeron, we point out that the commonly used vector vertex of the Pomeron coupling to quark is incorrect since it contradicts with the Pomeron property. We also claim that the soft Pomeron could be a tensor glueball ξ(2230) with quantum numbers IG JPC = 0+ 2++ and total decay width Γtot ≌ 100 MeV, which lies on the soft Pomeron trajectory αp = 1.08 + 0.20t. Therefore, the coupling vertex of the soft Pomeron to quark should be tensorial which is invariant under the charge conjugation and can explain why the inadequate vector coupling, γμ, of the soft Pomeron to quark is successful in dealing with Pomeron physics.

Quark Mass Dependence of Nucleon Magnetic Moment and Charge Radii

Understanding hadron structure within the framework of QCD is an extremely challenging problem. Our purpose here is to explain the model-independent consequences of the approximated chiral symmetry of QCD for two famous results concerning the quark structure of the nucleon. We show that both the apparent success of the constituent quark model in reproducing the ratio of proton to neutron magnetic moments and the apparent success of the Foldy term in reproducing the observed charge radius of the neutron are coincidental. That is, a relatively small change of the current quark mass would spoil both results.

Non-perturbative Aspects of QCD and Parameterized Quark Propagator

Based on the Global Color Symmetry Model, the non-perturbative QCD vacuum is investigated in the parameterized fully dressed quark propagator. Our theoretical predictions for various quantities characterized the QCD vacuum are in agreement with those predicted by many other phenomenological QCD inspired models. The successful predictions clearly indicate the extensive validity of our parameterized quark propagator used here. A detailed discussion on the arbitrariness in determining the integration cut-off parameter of µ in calculating QCD vacuum condensates and a good method, which avoided the dependence of calculating results on the cut-off parameter is also strongly recommended to readers.

Gasser–Leutwyler Coefficients of Chiral Lagrangian for Pseudoscalar Goldstone Bosons in Dyson–Schwinger Equations

Based on the Dyson–Schwinger equations of quark propagator in rainbow truncation with an effective gluon propagator, the ten unknown Gasser–Leutwyler coefficients of the chiral Lagrangian for pseudoscalar Goldstone bosons are predicted. The predicted values of Li with i = 1, 2, ..., 10 are in a reasonable agreement with empirical values used widely in literature, and the values predicted by many other theoretical models with QCD characteristics.