New derivation of the twist-3 gluon fragmentation contribution to polarized hyperon production

A novel method of formulating the twist-3 gluon fragmentation function contribution to hyperon polarization in proton-proton collision is presented. The employs a covariant gauge and takes full advantage Ward-Takahashi identities before performing collinear expansion. It provides robust way constructing general cross section formula also clear understanding for absence ghostlike terms leading order with respect QCD coupling constant.