29,197 research outputs found
Faddeev-Jackiw formalism for a topological-like oscillator in planar dimensions
The problem of a harmonic oscillator coupling to an electromagnetic potential
plus a topological-like (Chern-Simons) massive term, in two-dimensional space,
is studied in the light of the symplectic formalism proposed by Faddeev and
Jackiw for constrained systems.Comment: 17 pages, Latex file, to appear in Mod. Phys. Let.
Doped AB_2 Hubbard Chain: Spiral, Nagaoka and RVB States, Phase Separation and Luttinger Liquid Behavior
We present an extensive numerical study of the Hubbard model on the doped
AB chain, both in the weak coupling and the infinite-U limit. Due to the
special unit cell topology, this system displays a rich variety of phases as
function of hole doping () away from half-filling. Near half-filling,
spiral states develop in the weak coupling regime, while Nagaoka itinerant
ferromagnetism is observed in the infinite-U limit. For higher doping the
system phase-separates before reaching a Mott insulating phase of short-range
RVB states at . Moreover, for we observe a crossover,
which anticipates the Luttinger liquid behavior for .Comment: 11 pages, 13 figure
Behaviour of cone penetration tests in saturated sands
Imperial Users onl
The improved nuclear parton distributions
In this paper we propose an improvement of the EKS nuclear parton
distributions for the small x region of high energy processes, where the
perturbative high parton density effects cannot be disregarded. We analyze the
behavior of the ratios and and verify that at small x
they are strongly modified when compared to the EKS predictions. The
implications of our results for the heavy ion collisions in RHIC and LHC are
discussed.Comment: 16 pages, 2 figure
- …