30,741 research outputs found
On parton number fluctuations at various stages of the rapidity evolution
Starting with the interpretation of parton evolution with rapidity as a
branching-diffusion process, we describe the different kinds of fluctuations of
the density of partons which affect the properties of QCD scattering amplitudes
at moderately high energies. We then derive some of these properties as direct
consequences of the stochastic picture. We get new results on the expression of
the saturation scale of a large nucleus, and a modified geometric scaling valid
at intermediate rapidities for dipole-dipole scattering.Comment: 18 pages, 3 figures. v2: Improved writing; In particular, extended
discussion of the dipole-dipole case in Sec. 4. A few misprints corrected. To
appear in Phys. Lett.
A Modified "Bottom-up" Thermalization in Heavy Ion Collisions
In the initial stage of the bottom-up picture of thermalization in heavy ion
collisions, the gluon distribution is highly anisotropic which can give rise to
plasma instability. This has not been taken account in the original paper. It
is shown that in the presence of instability there are scaling solutions, which
depend on one parameter, that match smoothly onto the late stage of bottom-up
when thermalization takes place.Comment: 8 pages and 1 embedded figure, talk presented at the Workshop on
"Quark-Gluon Plasma Thermalization", Vienna, Austria, 10-12 August 200
Gluon Distribution Functions for Very Large Nuclei at Small Transverse Momentum
We show that the gluon distribution function for very large nuclei may be
computed for small transverse momentum as correlation functions of an
ultraviolet finite two dimensional Euclidean field theory. This computation is
valid to all orders in the density of partons per unit area, but to lowest
order in . The gluon distribution function is proportional to ,
and the effect of the finite density of partons is to modify the dependence on
transverse momentum for small transverse momentum.Comment: TPI--MINN--93--52/T, NUC--MINN--93--28/T, UMN--TH--1224/93, LaTex, 11
page
A technique to investigate space maintenance tasks
Effects of space suit pressurization and weightlessness on performance decrement in space maintenance activit
- …