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.

In this letter it will be demonstrated explicitly that the finite-element formulation of quantum electrodynamics is free from fermion doubling. We do this by (1) examining the lattice fermion propagator and using it to compute the one-loop vacuum polarization on the lattice, and (2) by an explict computation of vector and axial-vector current anomalies for an arbitrary rectangular lattice in th...

We calculate the S parameter of the standard model at one loop of fermions, using three different regularizations (dimensional, Pauli-Villars and lattice) and find an extra contribution to the S parameter besides the standard one for each case. This shows that the extra contribution recently reported for the lattice regularization is not necessarily tied to the non-decoupling effect of fermion ...

In the Mott-insulator regime, two species of ultracold atoms in an optical lattice can exhibit the low-energy counterflow motion. We construct effective Hamiltonians for the three classes of the two-species (fermion-fermion, boson-boson, and boson-fermion-type) insulators and reveal the conditions when the resulting ground state supports super-counter-fluidity (SCF), with the alternative being ...

We consider a new approach to fermion masses and mixings in which no special “horizontal” dynamics is invoked to account for the hierarchical pattern of charged fermion masses and for the peculiar features of neutrino masses. The hierarchy follows from the vertical, family-independent structure of the model, in particular from the breaking pattern of the Pati-Salam group. The lightness of the f...

We construct finite Dyson boson-fermion mappings of general collective algebras extended by single-fermion operators. A key element in the construction is the implementation of a similarity transformation which transforms boson-fermion images obtained directly from the supercoherent state method. In addition to the general construction, we give detailed applications to SO(2N), SU(l+1), SO(5), a...

Results are presented from a Monte Carlo simulation of the Nambu – Jona-Lasinio model with SU(2)⊗SU(2) chiral symmetry and Nf = 2 flavors of fermion. We show that fits to the equation of state are sensitive to the shape and extent of the assumed scaling region; the best fits favour a triviality scenario predicted by the large-Nf approximation, in which the scalar degrees of freedom are fermion ...

We discuss the scaling behaviour of different fermion actions in dynamical simulations of the 2-dimensional massive Schwinger model. We have chosen Wilson, hypercube, twisted mass and overlap fermion actions. As physical observables, the pion mass and the scalar condensate are computed for the above mentioned actions at a number of coupling values and fermion masses. We also discuss possibiliti...