4,854 research outputs found
Demonstration of the double Q^2-rescaling model
In this paper we have demonstrated the double Q^2-rescaling model (DQ^2RM) of
parton distribution functions of nucleon bounded in nucleus. With different
x-region of l-A deep inelastic scattering process we take different approach:
in high x-region (0.1\le x\le 0.7) we use the distorted QCD vacuum model which
resulted from topologically multi -connected domain vacuum structure of
nucleus; in low x-region (10^{-4}\le x\le10^{-3}) we adopt the Glauber
(Mueller) multi- scattering formula for gluon coherently rescattering in
nucleus. From these two approach we justified the rescaling parton distribution
functions in bound nucleon are in agreement well with those we got from DQ^2RM,
thus the validity for this phenomenologically model are demonstrated.Comment: 19 page, RevTex, 5 figures in postscrip
diffractive production in the direct photon process at HERA
We present a study of diffractive production in the direct
photon process at HERA based on the factorization theorem for lepton-induced
hard diffractive scattering and the factorization formalism of the
nonrelativistic QCD (NRQCD) for quarkonia production. Using the diffractive
gluon distribution function extracted from HERA data on diffractive deep
inelastic scattering and diffractive dijet photon production, we show that this
process can be studied at HERA with present integrated luminosity, and can give
valuable insights in the color-octet mechanism for heavy quarkonia production.Comment: Revtex, 21 pages, 7 EPS figure
The Tensor Current Divergence Equation in U(1) Gauge Theories is Free of Anomalies
The possible anomaly of the tensor current divergence equation in U(1) gauge
theories is calculated by means of perturbative method. It is found that the
tensor current divergence equation is free of anomalies.Comment: Revtex4, 7 pages, 2 figure
General formula for the four-quark condensate and vacuum factorization assumption
By differentiating the dressed quark propagator with respect to a variable
background field, the linear response of the dressed quark propagator in the
presence of the background field can be obtained. From this general method,
using the vector background field as an illustration, we derive a general
formula for the four-quark condensate . This formula contains the
corresponding fully dressed vector vertex and it is shown that factorization
for holds only when the dressed vertex is taken to be the bare one.
This property also holds for all other type of four-quark condensate.Comment: Revtex4, 11 pages, no figure
A Note on Transverse Axial Vector and Vector Anomalies in U(1) Gauge Theories
The transverse axial vector and vector anomalies in four-dimensional U(1)
gauge theories studied in [10] is reexamined by means of perturbative methods.
The absence of transverse anomalies for both axial vector and vector current is
verified. We also show that the Pauli-Villars regularization and dimensional
regularization give the same result on the transverse anomaly of both axial
vector and vector current.Comment: Revtex4, 8 pages, two figures. Largely revised, using the
Pauli-Villars regularization instead of dimensional regularization in the
main proof. Final form to be published in Physics Letters
Summation Inequalities to Bounded Real Lemmas of Discrete-Time Systems With Time-Varying Delay
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