Speaker
Description
The talk presents a new calculation of next-to-leading-order (NLO)
corrections of the strong and electroweak interactions to like-sign
W-boson scattering at the Large Hadron Collider, implemented in the
Monte Carlo integrator Bonsay. The calculation includes leptonic decays
of the W bosons and the whole tower of next-to-leading-order
contributions. Confirming an earlier NLO calculation, we find large pure
electroweak corrections of the order of ~ −12% for integrated cross
sections and even larger corrections in high-energy tails of
distributions. The electroweak corrections account for the major part of
the complete next-to-leading-order correction, which amounts to 15–20%
in size, depending on the details of the event selection chosen for
analysing vector-boson-scattering. Moreover, we compare the full
next-to-leading-order corrections to approximate results based on the
neglect of contributions that are not enhanced by the vector-boson
scattering kinematics (VBS approximation) and on resonance expansions
for the W-boson decays (double-pole approximation); the quality of this
approximation is good within ≲ 1.5% for integrated cross sections and
the dominating parts of the differential distributions. Finally, for the
leading-order predictions, we construct different versions of effective
vector-boson approximations, which are based on cross-section
contributions that are enhanced by collinear emission of W bosons off
the initial-state (anti)quarks; in line with previous findings in the
literature, it turns out that the approximative quality is rather
limited for applications at the LHC.
