Angular intermittency in QCD jets

Abstract

Using two methods, via fluctuations and correlations, an analytical formula is derived for the factorial multiplicity moments in a QCD jet at the Double Leading Logarithm accuracy. The resulting self-similar dependence on the solid-angle cell size is characteristic of an intermittency behaviour in angular variables. The intermittency indices depend on the diffusion angle through the running of α s . Physical features of jet fluctuations such as collimation at large angles and saturation at small angles are well described in the perturbative framework. A parameter-free prediction of angular intermittency is proposed for Z 0 decays into hadrons, assuming hadron-parton duality.

Energy conservation constraints on multiplicity correlations in QCD jets

“…It leads to a multifractal dimension slowly varying with the angular variables of observation. Furthermore, one observes [2], at small angles D q → d, i.e. a dynamical saturation of multifractality.…”

“…The structure of parton multiplicity correlations within QCD jets and in particular their selfsimilar properties have been recently studied [1,2,4]. The main result is twofold :…”

“…[1,2,4]. Some results exist which include Next-Leading-Log corrections to the anomalous dimensions [1], but they do not include the energy-conservation constraints.…”

Linear perturbations in Galileon gravity models

“…The other considers that the standard law of gravity, general relativity, fails on cosmological scales and must be completed by modifications capable of accelerating the Universe [6]. Models in the second class have attracted a lot of research interest recently, and significant progress has been made in both the theoretical modelling [7,8] and numerical simulations [9][10][11].…”

Long-range particle correlations and wavelets

“…It has lead to understanding of such global features as the intermittent dynamics (first proposed in [4]) and the fractal structure of phase space distributions (first proposed in [5]) in these processes. It has been shown [6,7,8] that, even at the level of the lowest perturbative approximations, the quantum chromodynamics (QCD) explains, at least qualitatively, this structure as resulting from the intermittent emission of subsequent jets with diminishing energies. Some completely new and unexpected features such as oscillating cumulant correlators of the multiplicity distributions were predicted in QCD [9,10] and confirmed by experiment (see, e.g., the review papers [2,3]).…”