Next-to-leading order QCD corrections to top quark spin correlations at hadron colliders: the reactions qq̄→tt̄(g)

Future hadron collider experiments are expected to record large to huge samples of tt̄ events. The analysis of these data with respect to tt̄ spin-spin correlations requires precise predictions of the production of these quark pairs in a general spin configuration. Therefore we have computed, at next-to-leading order (NLO) in the QCD coupling, the spin density matrices describing tt̄ production by quark antiquark annihilation, which is the dominant production process at the Tevatron. Moreover we have computed the strength of the tt̄ spin correlation at NLO, using various spin quantization axes.