Study of vector boson scattering and search for new physics in events with two same-sign leptons and two jets

TL;DR

This paper investigates vector boson scattering at 8 TeV using CMS data, measuring cross sections, testing the standard model, and setting limits on new physics including quartic interactions and doubly-charged Higgs bosons.

Contribution

It provides the first measurement of electroweak same-sign W-boson pair production at 8 TeV and sets new bounds on anomalous quartic gauge couplings and exotic Higgs states.

Findings

Observed significance of 2.0 standard deviations for electroweak W+/- W+/- production.

Measured cross sections for W+/- W+/- and WZ processes.

Set limits on quartic vector-boson interactions and doubly-charged Higgs boson production.

Abstract

A study of vector boson scattering in pp collisions at a center-of-mass energy of 8 TeV is presented. The data sample corresponds to an integrated luminosity of 19.4 inverse femtobarns collected with the CMS detector. Candidate events are selected with exactly two leptons of the same charge, two jets with large rapidity separation and dijet mass, and moderate missing transverse energy. The signal region is expected to be dominated by electroweak same-sign W-boson pair production. The observation agrees with the standard model prediction. The observed significance is 2.0 standard deviations, where a significance of 3.1 standard deviations is expected based on the standard model. Cross section measurements for W+/- W+/- and WZ processes in the fiducial region are reported. Bounds on the structure of quartic vector-boson interactions are given in the framework of dimension-eight effective field theory operators, as well as limits on the production of doubly-charged Higgs bosons.