331 research outputs found
Soft Colour Interactions and Diffractive Hard Scattering at the Tevatron
We make a brief presentation of the soft colour interactions models, the Soft
Colour Interaction and the Generalised Area Law, and summarise the results when
they are applied to p-pbar scattering. The models give a good description of
the Tevatron data on production of W, bottom and jets in diffractive events, as
well as jets with two rapidity gaps, alternatively leading particles. We also
give predictions for diffractive J/psi production and discuss diffractive Higgs
production at the Tevatron and LHC.Comment: 5 pages, 4 figures, uses JHEP style. Talk presented at the
International Europhysics Conference on High Energy Physics (EPS HEP 2001),
Budapest, 12-18 July 200
The high energy asymptotics of scattering processes in QCD
High energy scattering in the QCD parton model was recently shown to be a
reaction-diffusion process, and thus to lie in the universality class of the
stochastic Fisher-Kolmogorov-Petrovsky-Piscounov equation. We recall that the
latter appears naturally in the context of the parton model. We provide a
thorough numerical analysis of the mean field approximation, given in QCD by
the Balitsky-Kovchegov equation. In the framework of a simple stochastic toy
model that captures the relevant features of QCD, we discuss and illustrate the
universal properties of such stochastic models. We investigate in particular
the validity of the mean field approximation and how it is broken by
fluctuations. We find that the mean field approximation is a good approximation
in the initial stages of the evolution in rapidity.Comment: 31 pages, 20 figures. The code for BK evolution can be downloaded
from http://www.isv.uu.se/~enberg/BK/ v2: several points clarified,
discussion of the solutions to the mean-field evolution enhanced through the
study of a different class of initial conditions, references added;
conclusions unchanged. To appear in Phys. Rev.
Traveling waves and the renormalization group improved Balitsky-Kovchegov equation
I study the incorporation of renormalization group (RG) improved BFKL kernels in the Balitsky-Kovchegov (BK) equation which describes parton saturation. The RG improvement takes into account important parts of the next-to-leading and higher order logarithmic corrections to the kernel. The traveling wave front method for analyzing the BK equation is generalized to deal with RG-resummed kernels, restricting to the interesting case of fixed QCD coupling. The results show that the higher order corrections suppress the rapid increase of the saturation scale with increasing rapidity. I also perform a "diffusive" differential equation approximation, which illustrates that some important qualitative properties of the kernel change when including RG corrections
Hard Pomeron in exclusive meson production at ILC
We calculate the exclusive process gamma* gamma* ->rho rho at high energy.
The Born order estimate and the leading (LLA) and next to leading order (NLLA)
BFKL resummation effects show the feasibility of experimental detection in a
quite large range of Q2 values at future high energy e+e- linear colliders.Comment: 4 pages, Presented at Photon2005, International Conference on the
Structure and Interactions of the Photon, Warsaw 31.08-04.09.2005, by Samuel
Wallo
Testing the dynamics of high energy scattering using vector meson production
I review work on diffractive vector meson production in photon-proton
collisions at high energy and large momentum transfer, accompanied by proton
dissociation and a large rapidity gap. This process provides a test of the high
energy scattering dynamics, but is also sensitive to the details of the
treatment of the vector meson vertex.
The emphasis is on the description of the process by a solution of the
non-forward BFKL equation, i.e. the equation describing the evolution of
scattering amplitudes in the high-energy limit of QCD. The formation of the
vector meson and the non-perturbative modeling needed is also briefly
discussed.Comment: 17 pages, 8 figures. Brief review to appear in Mod. Phys. Lett.
Valtatien 4 liikennevirran ominaisuudet välillä Lahti-Heinola : S12 Pääteiden parantamisratkaisut
320086
- …