Measurement of inclusive and differential cross sections for W$^+$W$^-$ production in proton-proton collisions at $\sqrt{s}$ = 13.6 TeV

TL;DR

This paper reports precise measurements of W+W- production cross sections at 13.6 TeV using CMS data, including differential results based on jet multiplicity, and compares them with Standard Model predictions.

Contribution

First simultaneous study of WW events with different jet counts at 13.6 TeV, improving measurement precision and testing theoretical models.

Findings

Measured inclusive W+W- cross section of 125.7 ± 5.6 pb

Achieved better sensitivity than previous results

Compared differential cross sections with recent theories

Abstract

Measurements at $\sqrt{s}$ = 13.6 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 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 flavour 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 improvements 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 first time in proton-proton collisions, WW events with zero, one, and at least two reconstructed jets are studied simultaneously and compared with recent theoretical predictions.