Singlet g2 structure function in the next-to-leading order -: art. no. 094012

Following a previous study of the one-loop factorization of the nonsinglet g(2) structure function of the nucleon, we present in this paper the next-to-leading order coefficient functions in the singlet sector. To obtain the result, the partonic processes of virtual Compton scattering off two and three on-shell gluons are calculated. A key step in achieving the correct factorization is to separate the correct twist-two contribution. The Burkardt-Cottingham sum rule is nominally satisfied at this order.