Simplification of higher-twist evolution in the large Nc limit: why and why not
X. Ji - J. Osborne
Department of Physicsm University of Maryland, College Park, Maryland, MD 20742, USA
Received: 24 February 1999 / Published online: 18 June 1999
Working in the light-cone gauge, we find a simple procedure to calculate the autonomous one-loop Q2 evolution of the twist-three part of the nucleon gT(x, Q2) structure function in the large-Nc limit. Our approach allows us to investigate the possibility of a similar large-Nc simplification for other higher-twist evolutions. In particular, we show that it does not occur for the twist-four part of the f4(x, Q2), g3(x, Q2) and h3(x, Q2) distributions. We also argue that the simplification of the twist-three evolution does not persist beyond one loop.