Full NLO QCD corrections to off-shell ttbb production

Abstract

In this article, we report on the computation of the NLO QCD corrections to $\mathrm{p}\mathrm{p}\to {\mu }^{-}{\bar{\nu }}_{\mu }{\mathrm{e}}^{+}{\nu }_{\mathrm{e}}\bar{\mathrm{b}}\mathrm{b}\bar{\mathrm{b}}\mathrm{b}$ at the LHC, which is an irreducible background to $\mathrm{p}\mathrm{p}\to \mathrm{t}\bar{\mathrm{t}}\mathrm{H}(\to \mathrm{b}\bar{\mathrm{b}})$. This is the first time that a full NLO computation for a $2\to 8$ process with 6 external strongly-interacting partons is made public. No approximations are used, and all off-shell and interference effects are taken into account. Cross sections and differential distributions from the full computation are compared to results obtained by using a double-pole approximation for the top quarks. The difference between the full calculation and the one using the double-pole approximation is in general below 5\% but can reach 10\% in some regions of phase space.

Comments: 21 pages, 17 pdf figures. gb channels corrected. Matches the published version in PRD