Electroweak non-resonant NLO corrections to e+e−→W+W−bb¯ in the tt¯ resonance region

We analyze subleading electroweak effects in the top anti-top resonance production region in e+e− collisions which arise due to the decay of the top and anti-top quarks into the W+W−bb¯ final state. These are NLO corrections adopting the non-relativistic power counting v∼αs∼αEW. In contrast to the QCD corrections which have been calculated (almost) up to NNNLO, the parametrically larger NLO electroweak contributions have not been completely known so far, but are mandatory for the required accuracy at a future linear collider. The missing parts of these NLO contributions arise from matching coefficients of non-resonant production-decay operators in unstable-particle effective theory which correspond to off-shell top production and decay and other non-resonant irreducible background processes to tt¯ production. We consider the total cross section of the e+e−→W+W−bb¯ process and additionally implement cuts on the invariant masses of the W+b and W−b¯ pairs.