SIMPLE PARAMETRIZATION OF THE Q2 DEPENDENCE OF THE QUARK DISTRIBUTIONS IN QCD

We propose the following parametrization of the deep inelastic structure functions: F(x,Q2)=xβ(1-x)α(2) Σ n=0 NPn αβ)(x)Fn(Q2)=x β(1-x)α( Σ n=0 Nd(N,n,Q2)xn where Pn (α,β) (x) are Jacobi polynomials and where the Q2 dependence of the α(Q2) and fn(Q2) coefficients is deduced from QCD. We show that with few terms in this expansion we get good accuracy in the 3 GeV2 ≤ Q2 ≤ 15 000 GeV2 range. We also give a very simple fit to the d(N, n, Q2) for the valence part of the structure function. © 1979.