Quantum statistics and Altarelli-Parisi evolution equations
نویسنده
چکیده
The phenomenological evidence of quantum statistical effects in parton physics is here briefly summarized, and the recent good results obtained by parameterizing the parton distributions in terms of Fermi-Dirac and Bose-Einstein statistical functions are discussed. In this framework we study the modification of the scaling behaviour of parton distributions due to quantum statistical effects. In particular, by following a well-known formal analogy which holds between the Altarelli-Parisi evolution equations, at leading-log approximation, and a set of Boltzmann equations, we suggest a generalization of evolution equations to take into account Pauli exclusion principle and gluon induced emission. PACS number: 13.60.-r published in Nuovo Cim. A108 (1995) 867-882.
منابع مشابه
Solving the Altarelli-Parisi equations with truncated moments
The technique of truncated moments of parton distributions allows us to study scaling violations without making any assumption on the shape of parton distributions. The numerical implementation of the method is however difficult, since the evolution equations for truncated moments are not diagonal. We present a simple way to improve the efficiency of the numerical solution of the evolution equa...
متن کاملA Semianalytical Method to Solve Altarelli-parisi Evolution Equations
We discuss a new method to solve in a semianalytical way the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations at NLO order in the x-space. The method allows to construct an evolution operator expressed in form of a rapidly convergent series of matrices, depending only on the splitting functions. This operator, acting on a generic initial distribution, provides a very accurate solu...
متن کامل2 00 1 A fast and precise method to solve the Altarelli - Parisi equations in x space
A numerical method to solve linear integro-differential equations is presented. This method has been used to solve the QCD Altarelli-Parisi evolution equations within the H1 Collaboration at DESY-Hamburg. Mathematical aspects and numerical approximations are described. The precision of the method is discussed. This article is an extended version of an unpublished note [25]. In a recent publicat...
متن کاملLight - Ray Operators and their Application in QCD
The nonperturbative parton distribution and wave functions are directly related to matrix elements of light-ray (nonlocal) operators. These operators are generalizations of the standard local operators known from the operator product expansion. The renormalization group equation for these operators leads to evolution equations for more general distribution amplitudes which include the Altarelli...
متن کاملPhenomenology of Forward Hadrons in DIS : Fracture Functions and its Q 2 Evolution
We analyse recent data on the production of forward neutrons in deep inelas-tic scattering at HERA in the framework of a perturbative QCD description for semi-inclusive processes, which includes fracture functions. Using a model estimate for the non-perturbative piece of the fragmentation process, in fairly good agreement with the available data, we analyse the Q 2 dependence of the resulting f...
متن کامل