Measurement of inclusive and differential cross sections for W+W− production in proton-proton collisions at s=13.6 TeV

Abstract

Measurements at $\sqrt{s}=13.6\text{TeV}$ of the opposite-sign W boson pair production cross section in proton-proton collisions are presented. The data used in this study were collected with the CMS detector at the CERN LHC in 2022, and correspond to an integrated luminosity of 34.8${\text{fb}}^{-1}$. Events are selected by requiring one electron and one muon of opposite charge. A maximum likelihood fit is performed on signal- and background-enriched data categories defined by the flavor and charge of the leptons, the number of jets, and number of jets originating from b quarks. The overall sensitivity is significantly better than that of previous results with a similar integrated luminosity. The improvement comes from a more refined control of experimental uncertainties and an improved fit strategy. An inclusive $W^{+}{W}^{-}$ production cross section of $125.7\pm 5.6$ pb is measured, in agreement with standard model predictions. Cross sections are also reported in a fiducial region close to that of the detector acceptance, both inclusively and differentially, as a function of the jet multiplicity in the event. For the first time in proton-proton collisions, $WW$ events with zero, one, and at least two jets are studied simultaneously and compared with recent theoretical predictions.