Infrared analysis of propagators and vertices of Yang--Mills theory in Landau and Coulomb gauge

The infrared behaviour of gluon and ghost propagators, ghost-gluon vertex and three-gluon vertex is investigated for both the covariant Landau and the non-covariant Coulomb gauge. Assuming infrared ghost dominance, we find a unique infrared exponent in the d=4 Landau gauge, while in the d=3+1 Coulomb gauge we find two different infrared exponents. We also show that a finite dressing of the ghost-gluon vertex has no influence on the infrared exponents. Finally, we determine the infrared behaviour of the three-gluon vertex analytically and calculate it numerically at the symmetric point in the Coulomb gauge.Comment: 25 pages, 6 figures, accepted by Phys. Rev. D, references added, typos correcte

Entanglement generation via a completely mixed nuclear spin bath

We show that qubits coupled sequentially to a mesoscopic static completely mixed spin bath via the Heisenberg interaction can become highly entangled. Straightforward protocols for the generation of multipartite entangled (Greenberger-Horne-Zeilinger-)states are presented. We show the feasibility of an experimental realization in a quantum dot by the hyperfine interaction of an electron with the nuclear spins.Comment: 4+pages, 3 figure

Academic and Behavioral Reactions of Children with Disabilities to the Loss of a Firefighter Father: The New York City World Trade Center Attack 9/11/01

This five year comparative case study explores how children with disabilities responded to the loss of their firefighter father in the World Trade Center attack. Preliminary findings presented will be useful for teachers and researchers interested in designing appropriate interventions for children traumatized by the death of a parent