The Curci-Ferrari model with massive quarks at two loops

Massive quarks are included in the Curci-Ferrari model and the theory is renormalized at two loops in the MSbar scheme in an arbitrary covariant gauge.Comment: 8 latex page

Perturbative Part of the Non-Singlet Structure Function F_2 in the Large-N_F Limit

We have calculated $\bar{MS}$ Wilson coefficients and anomalous dimensions for the non-singlet part of the structure function F_2 in the large-N_F limit. Our result agrees with exact two and three loop calculations and gives the leading N_F dependence of the perturbative non-singlet Wilson coefficients to all orders in $\alpha_S$.Comment: 11 pages, including one figur

Magnetic and chiral universality classes in a 3D Yukawa model

The 3D Yukawa model with U(1) chiral symmetry is investigated in a broad interval of parameters using the Binder method. Critical exponents of the Wilson-Fisher (magnetic) and Gross-Neveu (chiral) universality classes are measured. The model is dominated by the chiral universality class. However at weak coupling we observe a crossover between both classes, manifested by difficulties with the Binder method which otherwise works well.Comment: 4 pages, contribution to LATTICE 9

Repeatability, Drift, and Aftereffect of Three Types of Aircraft Altimeters

In a series of laboratory tests of a number of sensitive altimeters 5 (Air Force type C-12 and C-13) and of precision altimeters (Air Force 8 type MA-1), the repeatability was determined for the full range of each type of instrument the drift characteristics were determined during 1-hour periods at various altitudes, and the drift and aftereffect were measured for a variety of simulated flights representative of some civil and military operations. For comparable altitude ranges, the repeatability errors of the C-12 and C-13 types were generally of the same order while those of the MA-1 type were somewhat smaller. The drift and aftereffect of the C-12 instruments were smaller than those of the C-13 instruments, and the drift and aftereffect of the MA-1 altimeters were considerably smaller than those of both types of the sensitive instruments. The drift of each of the three types of altimeters was found to increase with altitude and the drift of the precision type was found to increase with increasing rate of altitude change preceding the drift test

Two loop QCD vertices at the symmetric point

We compute the triple gluon, quark-gluon and ghost-gluon vertices of QCD at the symmetric subtraction point at two loops in the MSbar scheme. In addition we renormalize each of the three vertices in their respective momentum subtraction schemes, MOMggg, MOMq and MOMh. The conversion functions of all the wave functions, coupling constant and gauge parameter renormalization constants of each of the schemes relative to MSbar are determined analytically. These are then used to derive the three loop anomalous dimensions of the gluon, quark, Faddeev-Popov ghost and gauge parameter as well as the beta-function in an arbitrary linear covariant gauge for each MOM scheme. There is good agreement of the latter with earlier Landau gauge numerical estimates of Chetyrkin and Seidensticker.Comment: 36 latex pages, anc directory contains txt file with anomalous dimensions, beta-functions, coupling constant mappings, conversion functions and amplitudes in analytic for

Contract Report for The Science And Engineering Research Council. Contract Number Gr/F/06760. G.U. Aero Report 9201

This document constitutes the final report for SERC award No. GR/F/06760. It first details the work programme of the original proposal made in 1987 and notes the work done to illustrate completion and extensions beyond that proposed. For brevity, we confine the technical discussion to the salient features of a particular aerofoil, albeit the work was an integral part of a larger programme on dynamic stall. The extent of this work may be gleaned from the accompanying enclosures representing some recent activity at Glasgow University. Two of the main technical results from the present authors are worthy of note in that the first (i.e. a correletion for incipient dynamic stall) has been used both in industry (VAWT Ltd) and research (under SERC GR/F/63466) to propose new aerofoil shapes for wind turbines. The second, however, (negative lift at large incidence during ramp-down motions from the stalled condition) has generated a new research activity (funded under SERC GR/H167U). This and future prospects are discussed prior to the concluding remarks. These remarks express the authors opinion of the success and overall value of the programme

Renormalization group aspects of the local composite operator method

We review the current status of the application of the local composite operator technique to the condensation of dimension two operators in quantum chromodynamics (QCD). We pay particular attention to the renormalization group aspects of the formalism and the renormalization of QCD in various gauges.Comment: 13 latex pages, talk presented at RG0

Off-diagonal mass generation for Yang-Mills theories in the maximal Abelian gauge

We investigate a dynamical mass generation mechanism for the off-diagonal gluons and ghosts in SU(N) Yang-Mills theories, quantized in the maximal Abelian gauge. Such a mass can be seen as evidence for the Abelian dominance in that gauge. It originates from the condensation of a mixed gluon-ghost operator of mass dimension two, which lowers the vacuum energy. We construct an effective potential for this operator by a combined use of the local composite operators technique with algebraic renormalization and we discuss the gauge parameter independence of the results. We also show that it is possible to connect the vacuum energy, due to the mass dimension two condensate discussed here, with the non-trivial vacuum energy originating from the condensate , which has attracted much attention in the Landau gauge.Comment: 15 pages. Revtex. 1 .eps figure. Talk given by D.Dudal at XXV Encontro Nacional de Fisica de Particulas e Campos, Caxambu, Minas Gerais, Brasil, 24-28 Aug 2004. To appear in Brazilian Journal of Physic