Running coupling effects for the singlet structure function g_1 at small x

Ermolaev, B. I.; Greco, M.; Troyan, S. I.

Running coupling effects for the singlet structure function g_1 at small x

Authors

Ermolaev, B. I.

Greco, M.

Troyan, S. I.

Description

The running of the QCD coupling is incorporated into the infrared evolution equations for the flavour structure function g_1. The explicit expressions for g_1 including the total resummation of the double-logarithmic contributions and accounting for the running coupling are obtained. We predict that asymptotically g_1 ~ x^{- Δ_S}, with the intercept Δ_S = 0.86, which is more than twice larger than the non-singlet intercept. The impact of the initial quark (δq) and gluon (δg) densities on the sign of g_1 at x << 1 is discussed and explicit expressions relating δq and δg are obtained.
The sign of g_1 at small x is discussed in more details, 3 refs are added