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730
Infrared behaviour and
, 2007
"... Brooks, Paul M. (2006) Infrared behaviour and renormalization scheme invariance of QCD observables, ..."
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Brooks, Paul M. (2006) Infrared behaviour and renormalization scheme invariance of QCD observables,
Infrared Behaviour of Systems With
, 1997
"... We develop various complementary concepts and techniques for handling quantum fluctuations of Goldstone bosons.We emphasise that one of the consequences of the masslessness of Goldstone bosons is that the longitudinal fluctuations also have a diverging susceptibility characterised by an anomalous di ..."
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form for the generating functional of oneparticle irreducible vertices of the O(N) (non)–linear σ–models in the leading 1/N approximation.We show that this incorporates all infrared behaviour correctly both in linear and nonlinear σ – models. These techniques provide an alternative to chiral
Infrared Behaviour of the Gluon Propagator: Confining or Confined?
, 1995
"... The possible infrared behaviour of the gluon propagator is studied analytically, using the SchwingerDyson equations, in both the axial and the Landau gauge. The possibility of a gluon propagator less singular than 1/k 2 when k 2 → 0 is investigated and found to be inconsistent, despite claims to th ..."
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The possible infrared behaviour of the gluon propagator is studied analytically, using the SchwingerDyson equations, in both the axial and the Landau gauge. The possibility of a gluon propagator less singular than 1/k 2 when k 2 → 0 is investigated and found to be inconsistent, despite claims
INFRARED BEHAVIOUR OF SOFTLY BROKEN SQCD AND ITS DUAL
, 1998
"... Applying the recently obtained results on the renormalization of soft supersymmetrybreaking parameters, we investigate the infrared behaviour of the softly broken supersymmetric QCD as well as its dual theory in the conformal window. Under general assumptions on βfunctions, it is shown that the so ..."
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Applying the recently obtained results on the renormalization of soft supersymmetrybreaking parameters, we investigate the infrared behaviour of the softly broken supersymmetric QCD as well as its dual theory in the conformal window. Under general assumptions on βfunctions, it is shown
The Infrared Behaviour of the Pure YangMills Green Functions
, 2006
"... We study the infrared behaviour of the pure YangMills correlators using relations that are well defined in the nonperturbative domain. These are the SlavnovTaylor identity for threegluon vertex and the SchwingerDyson equation for ghost propagator in the Landau gauge. We also use several inputs ..."
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We study the infrared behaviour of the pure YangMills correlators using relations that are well defined in the nonperturbative domain. These are the SlavnovTaylor identity for threegluon vertex and the SchwingerDyson equation for ghost propagator in the Landau gauge. We also use several inputs
Infrared behaviour, sources and the Schwinger action principle
, 1994
"... An action principle technique is used to examine the infrared problem in the effective action for gauge field theories. It is shown by means of a dynamical analogy that the renormalization group and the ansatz of nonlocal sources can be simultaneously understood through generalized variations of a ..."
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An action principle technique is used to examine the infrared problem in the effective action for gauge field theories. It is shown by means of a dynamical analogy that the renormalization group and the ansatz of nonlocal sources can be simultaneously understood through generalized variations
The Infrared Behaviour of the Running Coupling in Landau Gauge QCD
, 2002
"... Approximate solutions for the gluon and ghost propagators as well as the running coupling in Landau gauge Yang–Mills theories are presented. These propagators obtained from the corresponding Dyson–Schwinger equations are in remarkable agreement with those of recent lattice calculations. The resultin ..."
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. The resulting running coupling possesses an infrared fixed point, αS(0) = 8.92/Nc for all gauge groups SU(Nc). Above one GeV the running coupling rapidly approaches its perturbative form.
INFRARED BEHAVIOUR OF MASSIVE SCALAR MATTER COUPLED TO GRAVITY
, 2001
"... Abstract. In the framework of causal perturbation theory we consider a massive scalar field coupled to gravity. In the field theoretic approach to quantum gravity (QG) we start with a massless second rank tensor field. This tensor field is then quantized in a covariant way in Minkowski space. This a ..."
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Abstract. In the framework of causal perturbation theory we consider a massive scalar field coupled to gravity. In the field theoretic approach to quantum gravity (QG) we start with a massless second rank tensor field. This tensor field is then quantized in a covariant way in Minkowski space. This article deals with the adiabatic limit for graviton radiative corrections in a scattering process of two massive scalar particles. We compute the differential crosssection for bremsstrahlung processes in which one of the outgoing particles emits a graviton of low energy, a so called soft graviton. Since the emited graviton will not be detected we have to integrate over all soft gravitons. 1.
The infrared behaviour of QCD Green's functions  Confinement, . . .
, 2000
"... Recent studies of QCD Green’s functions and their applications in hadronic physics are reviewed. We discuss the definition of the generating functional in gauge theories, in particular, the rôle of redundant degrees of freedom, possibilities of a complete gauge fixing versus gauge fixing in presence ..."
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Recent studies of QCD Green’s functions and their applications in hadronic physics are reviewed. We discuss the definition of the generating functional in gauge theories, in particular, the rôle of redundant degrees of freedom, possibilities of a complete gauge fixing versus gauge fixing in presence of Gribov copies, BRS invariance and positivity. The apparent contradiction between positivity and colour antiscreening in combination with BRS invariance in QCD is considered. Evidence for the violation of positivity by quarks and transverse gluons in the covariant gauge is collected, and it is argued that this is one manifestation of confinement. We summarise the derivation of the Dyson–Schwinger equations (DSEs) of QED and QCD. For the latter, the implications of BRS invariance on the Green’s functions are explored. The possible influence of instantons on DSEs is discussed in a twodimensional model. In QED in 2+1 and 3+1 dimensions, the solutions for Green’s functions provide tests of truncation schemes which can under certain circumstances be extended to the DSEs of QCD. We discuss some limitations of such extensions and assess the validity of assumptions for QCD as motivated from studies
Results 1  10
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730