Boris Ermolaev

 

Description of the spin-dependent structure function g_1 at arbitrary x and Q^2 .

 

The Standard Approach (SA) for description of g_1 is based on the DGLAP evolution equations and therefore can be used in the kinematic region of large x and Q^2 only. Extrapolating SA into the small-x region is usually done with complementing DGLAP by the singular fits for initial parton densities (IPD), however without theoretical grounds. Alternative way to describe the small-x region is the total resummation of leading logarithms of x. In this case IPD are not singular and can be given by much simpler expressions. In order to describe the small-Q^2 region, we use the shift of Q^2 . Finally in order to describe the region of large x, the interpolation expressions for g_1 combining DGLAP and the enlisted above small-x results can be used.