====== TTP08-11 Ultrasoft contribution to heavy quark pair production near threshold ====== We compute the third-order correction to the heavy-quark current correlation function due to th e emission and absorption of an ultrasoft gluon. Our result supplies a missing contribution to top-quark pair production near threshold and the determination of the bottom quark mass from QC D sum rules. |**Martin Beneke, Yuichiro Kiyo** | |** Phys.Lett. B668: (2008.) :143-147 ** | | {{preprints:2008:ttp08-11.pdf|PDF}} {{preprints:2008:ttp08-11.ps|PostScript}} [[http://arxiv.org/abs/0804.4004|arXiv]] | | |