scholarly journals INDUCED COLOR CURRENT BY GLUON IN BACKGROUND QCD

2001 ◽  
Vol 10 (06) ◽  
pp. 483-499 ◽  
Author(s):  
Q. WANG ◽  
C.-W. KAO ◽  
G. C. NAYAK ◽  
W. GREINER
Keyword(s):  
Background Field ◽  
Field Method ◽  
Integral Approach ◽  
Asymptotic Freedom ◽  
Displacement Current ◽  
Inhomogeneous Field ◽  
Induced Current ◽  
Coupling Constant ◽  
Abelian Gauge ◽  
Background Field Method

By using the background field method of QCD in a path integral approach, we derive the equation of motion for the classical chromofield and that for the gluon in a system containing the gluon and the classical chromofield simultaneously. This inhomogeneous field equation contains an induced current term, which is the expectation value of a combination of composite operators including linear, square and cubic terms of the gluon field. We also derive identities for the current from gauge invariance and calculate the current at the leading order where the current induced by the gluon is opposite in sign to that induced by the quark. This is just the feature of the non-Abelian gauge field theory which has asymptotic freedom. Physically, the induced current can be treated as a "displacement" current in the polarized vacuum, and its effect is equivalent to redefining the field and the coupling constant.

scholarly journals RENORMALIZATION OF FUNCTIONAL SCHRÖDINGER EQUATION BY BACKGROUND FIELD METHOD

1998 ◽  
Vol 13 (21) ◽  
pp. 1709-1717 ◽  
Author(s):  
K. ZAREMBO
Keyword(s):  
Renormalization Group ◽  
Schrödinger Equation ◽  
Ground State ◽  
Schrodinger Equation ◽  
Background Field ◽  
Field Method ◽  
Asymptotic Freedom ◽  
Yang Mills ◽  
State Wave ◽  
Background Field Method

Renormalization group transformations for Schrödinger equation are performed in both φ4 and Yang–Mills theories. The dependence of the ground state wave functional on rapidly oscillating fields is found. For Yang–Mills theory, this dependence restricts a possible form of variational ansatz compatible with asymptotic freedom.

scholarly journals Two-loop renormalisation of gauge theories in 4D implicit regularisation and connections to dimensional methods

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
A. Cherchiglia ◽  
D. C. Arias-Perdomo ◽  
A. R. Vieira ◽  
M. Sampaio ◽  
B. Hiller
Keyword(s):  
Quantum Electrodynamics ◽  
Dimensional Regularization ◽  
Background Field ◽  
Field Method ◽  
Loop Order ◽  
Abelian Gauge ◽  
Gauge Invariant ◽  
Yang Mills ◽  
Lorentz Algebra ◽  
Background Field Method

AbstractWe compute the two-loop $$\beta $$ β -function of scalar and spinorial quantum electrodynamics as well as pure Yang–Mills and quantum chromodynamics using the background field method in a fully quadridimensional setup using implicit regularization (IREG). Moreover, a thorough comparison with dimensional approaches such as conventional dimensional regularization (CDR) and dimensional reduction (DRED) is presented. Subtleties related to Lorentz algebra contractions/symmetric integrations inside divergent integrals as well as renormalisation schemes are carefully discussed within IREG where the renormalisation constants are fully defined as basic divergent integrals to arbitrary loop order. Moreover, we confirm the hypothesis that momentum routing invariance in the loops of Feynman diagrams implemented via setting well-defined surface terms to zero deliver non-abelian gauge invariant amplitudes within IREG just as it has been proven for abelian theories.

A MODEL LAGRANGIAN FOR STRONG INTERACTIONS AT LARGE DISTANCES

1989 ◽  
Vol 04 (03) ◽  
pp. 293-302 ◽  
Author(s):  
MEIUN SHINTANI
Keyword(s):  
Background Field ◽  
String Tension ◽  
Field Method ◽  
Strong Interactions ◽  
Coupling Constant ◽  
Running Coupling ◽  
Free Region ◽  
Running Coupling Constant ◽  
Background Field Method ◽  
The One

On the basis of the massive vector dipole theory as a model for strong interactions at large distances, we compute the counterterm Lagrangian at the one-loop level in the background field method. By smoothly relating the running coupling constant in the confining region to that in the asymptotically free region, we deduce a relationship between the string tension and the QCD scale parameter Λ QCD . With an input data of the string tension, we evaluate the value of Λ QCD . The lower bound to the distances where the dipole theory is valid relies on the number of flavors. The theory seems to be meaningful for six generations or less.

Evolution of Coupling Constant in Hot QCD

1997 ◽  
Vol 06 (01) ◽  
pp. 45-64
Author(s):  
M. Chaichian ◽  
M. Hayashi
Keyword(s):  
Finite Temperature ◽  
Lorentz Invariance ◽  
Background Field ◽  
Field Method ◽  
Renormalization Group Equation ◽  
Group Equation ◽  
Coupling Constant ◽  
Time Formalism ◽  
Background Field Method ◽  
The One

The evolution of QCD coupling constant at finite temperature is considered by making use of the finite temperature renormalization group equation up to the one-loop order in the background field method with the Feynman gauge and the imaginary time formalism. The results are compared with the ones obtained in the literature. We point out, in particular, the origin of the discrepancies between different calculations, such as the choice of gauge, the breakdown of Lorentz invariance, imaginary versus real time formalism and the applicability of the Ward identities at finite temperature.

scholarly journals NONCOMMUTATIVITY AND NON-ANTICOMMUTATIVITY PERTURBATIVE QUANTUM GRAVITY

2012 ◽  
Vol 27 (13) ◽  
pp. 1250075 ◽  
Author(s):  
MIR FAIZAL
Keyword(s):  
Quantum Gravity ◽  
Lagrangian Density ◽  
Background Field ◽  
Field Method ◽  
Gauge Fixing ◽  
Perturbative Quantum ◽  
Background Field Method

In this paper, we will study perturbative quantum gravity on supermanifolds with both noncommutativity and non-anticommutativity of spacetime coordinates. We shall first analyze the BRST and the anti-BRST symmetries of this theory. Then we will also analyze the effect of shifting all the fields of this theory in background field method. We will construct a Lagrangian density which apart from being invariant under the extended BRST transformations is also invariant under on-shell extended anti-BRST transformations. This will be done by using the Batalin–Vilkovisky (BV) formalism. Finally, we will show that the sum of the gauge-fixing term and the ghost term for this theory can be elegantly written down in superspace with a two Grassmann parameter.

scholarly journals FIELD DECOMPOSITION AND THE GROUND STATE STRUCTURE OF SU(2) YANG–MILLS THEORY

2002 ◽  
Vol 17 (25) ◽  
pp. 3681-3688 ◽  
Author(s):  
LISA FREYHULT
Keyword(s):  
Effective Potential ◽  
Ground State ◽  
Scalar Fields ◽  
Background Field ◽  
Field Method ◽  
Gauge Fields ◽  
Ground State Structure ◽  
State Structure ◽  
Yang Mills ◽  
Background Field Method

We compute the effective potential of SU(2) Yang–Mills theory using the background field method and the Faddeev–Niemi decomposition of the gauge fields. In particular, we find that the potential will depend on the values of two scalar fields in the decomposition and that its structure will give rise to a symmetry breaking.

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