A comprehensive framework for studying W ′ and Z ′ bosons at hadron colliders with automated jet veto resummation

International audienceThe production of high-mass, color-singlet particles in hadron collisions is universally accompanied by initial state QCD radiation that is predominantly soft with respect to the hard process scale Q and/or collinear with respect to the beam axis. At TeV-scale colliders, this is in contrast to top quark and multijet processes, which are hard and central. Consequently, vetoing events with jets possessing transverse momenta above p Veto T in searches for new color-singlet states can efficiently reduce non-singlet backgrounds, thereby increasing experimental sensitivity. To quantify this generic observation, we investigate the production and leptonic decay of a Sequential Standard Model W boson at the 13 TeV Large Hadron Collider. We systematically consider signal and background processes at next-to-leading-order (NLO) in QCD with parton shower (PS) matching. For color-singlet signal and background channels, we resum Sudakov logarithms of the form α j s (p Veto T) log k (Q/p Veto T) up to next-to-next-to-leading logarithmic accuracy (NNLL) with NLO matching. We obtain our results using the MadGraph5 aMC@NLO and MadGraph5 aMC@NLO-SCET frameworks, respectively. Associated Universal Feyn-Rules Output model files capable of handling NLO+PS-and NLO+NNLL-accurate computations are publicly available. We find that within their given uncertainties, both the NLO+PS and NLO+NNLL(veto) calculations give accurate and consistent predictions. Consequently, jet vetoes applied to color-singlet processes can be reliably modeled at the NLO+PS level. With respect to a b-jet veto of p Veto T = 30 GeV, flavor-agnostic jet vetoes of p Veto T = 30 − 40 GeV can further reduce single top and tt rates by a factor of 2-50 at a mild cost of the signal rate. Jet vetoes can increase the signal-to-noise ratios by roughly 10% for light W boson masses of 30 − 50 GeV and 25%-250% for masses of 300-800 GeV