T. Gehrmann et Wj. Stirling, ANALYTIC APPROACHES TO THE EVOLUTION OF POLARIZED PARTON DISTRIBUTIONS AT SMALL-X, Physics letters. Section B, 365(1-4), 1996, pp. 347-358
The Q(2) evolution of polarised parton distributions at small x is stu
died. Various analytic approximations are critically discussed. We com
pare the full evolution with that obtained from the leading-pole appro
ximation to the splitting functions, and show that the validity of thi
s approximation depends critically on the x --> 0 behaviour of the sta
rting distributions. A new analytic solution which is valid at small x
is obtained, and its domain of applicability is discussed.