7 research outputs found
Quantum Field Kinetics of QCD: Quark-Gluon Transport Theory for Lightcone Dominated Processes
A quantum kinetic formalism is developed to study the dynamical interplay of
quantum and statistical-kinetic properties of non-equilibrium multi-parton
systems produced in high-energy QCD processes. The approach provides the means
to follow the quantum dynamics in both space-time and energy-momentum, starting
from an arbitrary initial configuration of high-momentum quarks and gluons.
Using a generalized functional integral representation and adopting the
`closed-time-path' Green function techniques, a self-consistent set of
equations of motions is obtained: a Ginzburg-Landau equation for a possible
color background field, and Dyson-Schwinger equations for the 2-point functions
of the gluon and quark fields. By exploiting the `two-scale nature' of
light-cone dominated QCD processes, i.e. the separation between the quantum
scale that specifies the range of short-distance quantum fluctuations, and the
kinetic scale that characterizes the range of statistical binary inter-
actions, the quantum-field equations of motion are converted into a correspon-
ding set of `renormalization equations' and `transport equations'. The former
describe renormalization and dissipation effects through the evolution of the
spectral density of individual, dressed partons, whereas the latter determine
the statistical occurrence of scattering processes among these dressed partons.
The renormalization equations and the transport equations are coupled, and
hence must be solved self-consistently. This amounts to evolving the
multi-parton system, from a specified initial configuration, in time and full
7-dimensional phase-space. This description provides a proba- bilistic
interpretation and is therefore of important practical value for the solution
of the dynamical equations of motion, e.g. by Monte Carlo simulation.Comment: 70 pages, latex, 12 figures as uu-encoded postscript fil
Gender and 5-years course of psychosis patients: focus on clinical and social variables
Most studies on gender and psychosis have focused on gender differences at illness onset or on the long-term outcome, whereas little is known about the impact of gender on the first years after psychosis onset. A total of 185 first episode psychosis (FEP) patients were followed for 5 years after psychosis onset, and gender differences were explored in psychopathology (PANSS), needs for care (CAN), and insight (SAI-E). Male patients showed more negative symptoms than females over time, whereas female patients showed higher levels of depressive symptoms than males throughout the study period. In addition, female patients presented more functioning unmet needs for care, but higher levels of insight into illness than males. Therapy and rehabilitative programs for FEP patients should be gender-targeted, as gender has proved to impact on psychopathology, needs for care, and insight in the very first years following psychosis onset
Evolution of e p fragmentation and multiplicity distributions in the Breit frame
Low x deep-inelastic ep scattering data, taken in 1994 at the H1 detector at
HERA, are analysed in the Breit frame of reference. The evolution of the peak
and width of the current hemisphere fragmentation function is presented as a
function of Q and compared with e+e- results at equivalent centre of mass
energies. Differences between the average charged multiplicity and the
multiplicity of e+e- annihilations at low energies are analysed. Invariant
energy spectra are compared with MLLA predictions. Distributions of
multiplicity are presented as functions of Bjorken-x and Q^2, and KNO scaling
is discussed.Comment: 24 pages, 9 Figures, figure 2 correcte