We analyze the implications of a Higgs discovery on possible " new–physics " scenarios, for m H up to ∼ 700 GeV. For this purpose we critically review lower and upper limits on the Higgs mass in the SM and in the MSSM, respectively. Furthermore, we discuss the general features of possible " heavy " (m H > ∼ 2m Z) Higgs scenarios by means of a simple heavy–fermion condensate model.

Recently the two-loop next-to-leading logarithmic (NLL) virtual corrections to arbitrary processes with massless external fermions have been calculated. Within the spontaneously broken electroweak theory the oneand two-loop mass singularities have been derived to NLL accuracy and expressed as universal correction factors depending only on the quantum numbers of the external particles. This talk...

In this paper, we construct a supersymmetric composite axion (c-axion) model based on the gauge group SU(N) × SU(M), which is one possible physical application of the N=1 duality. The dual of SU(M) is interpreted as the color gauge group. We illustrate the existence of c-axion for the case of one dual quark in the dual gauge group SU(M̃ ). 14.80.Mz, 11.30–j, 11.30.Pb Typeset using REVTEX E-mail:...

We show that composite fermions with masses much smaller than the scale of confinement arise naturally in certain models which admit dynamical breakdown of chiral symmetry. The models are such that to leading order some of the fermions remain massless but pick up small dynamical masses at subleading order.

Expanding upon the arguments of Sharpe, we explicitly implement the Symanzik improvement program demonstrating the absence of order a terms in the staggered fermion action. We propose a general program to improve fermion operators to remove O(a) corrections from their matrix elements, and demonstrate this program for the examples of matrix elements of fermion bilinears and BK . We also determin...

We study the QCD scattering amplitudes for q̄q → gg and q̄q → ggg where q is a massive fermion. Using a particular choice of massive fermion spinor we are able to derive very compact expressions for the partial spin amplitudes for the 2 → 2 process. We then investigate the corresponding 2 → 3 amplitudes using the BCFW recursion technique. For the helicity conserving partial amplitudes we again de...

The local composite operator A2 is analysed in pure Yang-Mills theory in the Landau gauge within the algebraic renormalization. It is proven that the anomalous dimension of A2 is not an independent parameter, being expressed as a linear combination of the gauge β function and of the anomalous dimension of the gauge fields. Research Assistant of The Fund For Scientific Research-Flanders, Belgium...

Composite optical vortices may form when two or more beams interfere. Using analytical and numerical techniques, we describe the motion of these optical phase singularities as the relative phase or amplitude of two interfering collinear nonconcentric beams is varied. The creation and the annihilation of vortices are found, as well as vortices having translational velocities exceeding the speed ...