22 research outputs found
The Pole Part of the 1PI Four-Point Function in Light-Cone Gauge Yang-Mills Theory
The complete UV-divergent contribution to the one-loop 1PI four-point
function of Yang-Mills theory in the light-cone gauge is computed in this
paper. The formidable UV-divergent contributions arising from each four-point
Feynman diagram yield a succinct final result which contains nonlocal terms as
expected. These nonlocal contributions are consistent with gauge symmetry, and
correspond to a nonlocal renormalization of the wave function. Renormalization
of Yang-Mills theory in the light-cone gauge is thus shown explicitly at the
one-loop level.Comment: 35 pages, 18 figures. To be published in Nuc. Phys.
The Wilson Loop in Yang-Mills Theory in the General Axial Gauge
We test the unified-gauge formalism by computing a Wilson loop in Yang-Mills
theory to one-loop order. The unified-gauge formalism is characterized by the
abritrary, but fixed, four-vector , which collectively represents the
light-cone gauge , the temporal gauge , the pure axial
gauge and the planar gauge . A novel feature of the
calculation is the use of distinct sets of vectors, and , for the path and for the gauge-fixing
constraint, respectively. The answer for the Wilson loop is independent of
, and agrees numerically with the result obtained in the Feymman
gauge.Comment: 12 pages, 2 figure
QCD Pressure at Two Loops in the Temporal Gauge
We apply the method of \underline{zeta} functions, together with the
-prescription for the temporal gauge, to evaluate the thermodynamic
pressure in QCD at finite temperature . Working in the imaginary-time
formalism and employing a special version of the unified-gauge prescription, we
show that the pure-gauge contribution to the pressure at two loops is given by
P_2^{\mbox{{\scriptsize gauge}}} = -(g^2/144)N_cN_gT^4, where and
denote the number of colours and gluons, respectively. This result agrees with
the value in the Feynman gauge.Comment: 19 pages, 2 figures, list of 63 integral
Two-Loop Quark Self-Energy in a New Formalism (II): Renormalization of the Quark Propagator in the Light-Cone Gauge
The complete two-loop correction to the quark propagator, consisting of the
spider, rainbow, gluon bubble and quark bubble diagrams, is evaluated in the
noncovariant light-cone gauge (lcg). (The overlapping self-energy diagram had
already been computed.) The chief technical tools include the powerful matrix
integration technique, the n^*-prescription for the spurious poles of 1/qn, and
the detailed analysis of the boundary singularities in five- and
six-dimensional parameter space. It is shown that the total divergent
contribution to the two-loop correction Sigma_2 contains both covariant and
noncovariant components, and is a local function of the external momentum p,
even off the mass-shell, as all nonlocal divergent terms cancel exactly.
Consequently, both the quark mass and field renormalizations are local. The
structure of Sigma_2 implies a quark mass counterterm of the form ,
\tilde\alpha_s = g^2\Gamma(\eps)(4\pi)^{\eps -2}, with W depending only on
the dimensional regulator epsilon, and on the numbers of colors and flavors. It
turns out that \delta m(lcg) is identical to the mass counterterm in the
general linear covariant gauge. Our results are in agreement with the
Bassetto-Dalbosco-Soldati renormalization scheme.Comment: 36 pages Latex, 5 eps figures, to appear in Nucl.Phys.
Two-loop quark self-energy in a new formalism; 1, overlapping divergences
A new integration technique for multi-loop Feynman integrals, called the \it matrix method\rm, is developed and then applied to the divergent part of the overlapping two-loop quark self-energy function \,i\Sigma\, in the light-cone gauge \ n\!\cdot\!A^a(x)=0,\ n^2=0. It is shown that the coefficient of the double-pole term is strictly local, even off mass-shell, while the coefficient of the single-pole term contains local as well as nonlocal parts. On mass-shell, the single-pole part is local, of course. It is worth noting that the original overlapping self-energy integral reduces eventually to 10 covariant and 38 noncovariant-gauge integrals. We were able to verify explicitly that the {\it divergent parts} of the 10 double covariant-gauge integrals agreed precisely with those currently used to calculate radiative corrections in the Standard Model. \par Our new technique is amazingly powerful, being applicable to massive and massless integrals alike, and capable of handling both covariant-gauge integrals and the more difficult noncovariant-gauge integrals. Perhaps the most important feature of the matrix method is the ability to execute the 4\omega-dimensional momentum integrations in a single operation, exactly and in analytic form. The method works equally well for other axial-type gauges, notably the temporal gauge (n^2>0) and the pure axial gauge (n^2<0)
Split Dimensional Regularization for the Coulomb Gauge
A new procedure for regularizing Feynman integrals in the noncovariant
Coulomb gauge is proposed for Yang-Mills theory. The procedure is based on a
variant of dimensional regularization, called split dimensional regularization,
which leads to internally consistent, ambiguity-free integrals. It is
demonstrated that split dimensional regularization yields a one-loop Yang-Mills
self-energy that is nontransverse, but local. Despite the noncovariant nature
of the Coulomb gauge, ghosts are necessary in order to satisfy the appropriate
Ward/BRS identity. The computed Coulomb-gauge Feynman integrals are applicable
to both Abelian and non-Abelian gauge models.
PACS: 11.15, 12.38.CComment: 19 pages, 2 figures, 1 table, 72 references. This Replaced version
clarifies why the Coulomb gauge requires a new type of regularization, and
why our new regularization is compatible with Wick rotation. Results and
table of integrals are unchanged. To appear in Nuclear Physics
Determination of Pt–DNA adducts and the sub-cellular distribution of Pt in human cancer cell lines and the leukocytes of cancer patients, following mono- or combination treatments, by inductively-coupled plasma mass spectrometry
This is the author’s version of a work that was accepted for publication in the International Journal of Mass Spectrometry. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published at: http://dx.doi.org/10.1016/j.ijms.2010.11.01