Gouranga C Nayak ∗ 1 Department of Physics, University of Arizona, Tucson, AZ 85721, USA Abstract In this paper we derive a gauge fixing identity by varying the covariant gauge fixing term in Z[A, J, η, η̄] in the background field method of QCD in pure gauge. Using this gauge fixing identity we establish a relation between Z[J, η, η̄] in QCD and Z[A, J, η, η̄] in background field method of QCD in ...

The textit{QIF}  (Quadrant Interlocking Factorization) method of Evans and Hatzopoulos solves linear equation systems using textit{WZ}  factorization. The  WZ factorization can be faster than the textit{LU} factorization  because,  it performs the simultaneous evaluation of two columns or two rows. Here, we present a  method for computing the real and integer textit{WZ} and  textit{ZW} factoriz...

The collinear factorization theorem, combined with finite-order calculations in perturbative QCD, provides a powerful framework to obtain predictions for many collider observables. However, observables which involve multiple energy scales, transverse degrees of freedom cannot be neglected, and have resummed all orders the QCD running coupling order reliable theoretical predictions, capable desc...

We discuss various tests of the factorization hypothesis making use of the close relationship between semi-leptonic and factorized nonleptonic decay amplitudes. It is pointed out that factorization leads to truely model-independent predictions for the ratio of nonleptonic to semi-leptonic decay rates, if in the nonleptonic decay a spin one meson of arbitrary mass or a pion take the place of the...

Factorization properties of one-loop gauge theory amplitudes have been used as checks on explicitly computed amplitudes and in the construction of ansätze for higher-point ones. In massless theories, such as QCD at high energies, infrared divergences complicate factorization. Here we prove that factorization in such theories is described by a set of universal functions. In particular, a proof o...

We present an analysis of two-loop mixed QCD and electroweak corrections to the decay of the Z boson into light quarks. We find that the naive factorization of QCD and electroweak corrections does not describe correctly the two-loop effects. The nonfactorizable corrections shift the width of the Z boson by approximately −0.59(3) MeV and increase the central value of the strong coupling constant...