Relations among polarized and unpolarized splitting functions beyond leading order
نویسندگان
چکیده
The role of various symmetries in the evaluation of splitting functions and coefficient functions is discussed. The scale invariance in hard processes is known to be a guiding tool to understand the dynamics. We discuss the constraints on splitting functions coming from various symmetries such as scale, conformal and supersymmetry. We also discuss the Drell-Levy-Yan relation among splitting and coefficient functions in various schemes. The relations coming from conformal symmetry are also presented.
منابع مشابه
Next-to-Leading Order Evolution of Polarized and Unpolarized Fragmentation Functions
We determine the two-loop ’time-like’ Altarelli-Parisi splitting functions, appearing in the next-to-leading order Q-evolution equations for fragmentation functions, via analytic continuation of the corresponding ’space-like’ splitting functions for the evolution of parton distributions. We do this for the case of unpolarized fragmentation functions and for the first time also for the functions...
متن کاملar X iv : h ep - p h / 96 07 22 3 v 1 2 J ul 1 99 6 RAL - TR - 96 - 046 June 1996 THE POLARIZED TWO - LOOP SPLITTING FUNCTIONS
We present a brief description of the light-cone gauge calculation of the spin-dependent next-to-leading order splitting functions. It has recently become possible to perform analyses of the spin-dependent parton distributions of a longitudinally polarized hadron at next-to-leading order (NLO) accuracy of QCD. A first such phenomenological NLO study, taking into account all available experiment...
متن کاملSpin-Dependent Parton Distributions of the Longitudinally Polarized Photon Beyond the Leading Order
A next-to-leading order (NLO) QCD analysis of the spin-dependent parton distributions ∆f(x,Q) of the longitudinally polarized photon and of its structure function g 1 (x,Q ) is performed within the framework of the radiative parton model. The important issues of a suitably chosen factorization scheme and related boundary conditions are discussed in detail. The typical effects of the NLO correct...
متن کاملA Study of Structure Functions for the Bag Beyond Leading Order
There has recently been surprising progress in understanding the spin and flavor dependence of deep inelastic structure functions in terms of the same physics needed in the simple quark models used for hadronic spectroscopy. However, the corresponding scale is usually very low, casting doubt on the use of leading order QCD evolution. We show that the conclusions are not significantly altered if...
متن کاملHarmonic Sums and Mellin Transforms up to two–loop Order
A systematic study is performed on the finite harmonic sums up to level four. These sums form the general basis for the Mellin transforms of all individual functions fi(x) of the momentum fraction x emerging in the quantities of massless QED and QCD up to two–loop order, as the unpolarized and polarized splitting functions, coefficient functions, and hard scattering cross sections for space and...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1998