A Gaussian effective theory for gluon saturation
نویسندگان
چکیده
We construct a Gaussian approximation to the effective theory for the Colour Glass Condensate which describes correctly the gluon distribution both in the low density regime at high transverse momenta (above the saturation scale Qs), and in the high density regime below Qs, and provides a simple interpolation between these two regimes. At high momenta, the effective theory reproduces the BFKL dynamics, while at low momenta, it exhibits gluon saturation and, related to it, colour neutrality over the short distance scale 1/Qs ≪ 1/ΛQCD. Gauge–invariant quantities computed within this approximation are automatically infrared finite.
منابع مشابه
Saturation and Universality in QCD at small x
We find approximate solutions to the renormalization group equation which governs the quantum evolution of the effective theory for the Color Glass Condensate. This is a functional Fokker-Planck equation which generates in particular the evolution equations for Wilson-line operators previously derived by Balitsky and Kovchegov within perturbative QCD. In the limit where the transverse momentum ...
متن کاملImpact of Input Pump Profile on the Gain Spectrum and the Saturation Behavior of One-Pump Fiber Optical Parametric Amplifiers
In this article, the impact of input pump profile on the gain spectrum as well as the saturation behavior of one-pump fiber optical parametric amplifiers (FOPAs) is investigated. Since in practical circumstances, pump sources used for FOPAs have Lorentz-Gaussian profile instead of Gaussian, a more realistic case is considered for simulating FOPAs in this article. The results of simulations for ...
متن کاملLiouville field theory for gluon saturation in QCD at high energy
We argue that quantum Liouville field theory supplemented with a suitable source term is the effective theory which describes the short–range correlations of the gluon saturation momentum in the two– dimensional impact–parameter space, at sufficiently high energy and for a large number of colors. This is motivated by recent developments concerning the stochastic aspects of the high–energy evolu...
متن کاملA Tachyonic Gluon Mass: between Infrared and Ultraviolet
The gluon spin coupling to a Gaussian correlated background gauge field induces an effective tachyonic gluon mass. It is momentum dependent and vanishes in the UV only like 1/p2. In the IR, we obtain stabilization through a positive mconf(p 2) related to confinement. Recently a purely phenomenological tachyonic gluon mass was used to explain the linear rise in the qq̄ static potential at small d...
متن کاملThe Transverse Energy as a Barometer of a Saturated Plasma
The evolution of the gluon plasma produced with saturation initial conditions is calculated via Boltzmann transport theory for nuclear collisions at high energy. The saturation scale increases with A and √ s, and thus we find that the perturbative rescattering rate decreases relative to the initial longitudinal expansion rate of the plasma. The effective longitudinal pressure remains significan...
متن کامل