A measurement of the W+W- boson pair production cross section in proton-proton collisions at sqrt(s) = 13 TeV is presented. The data used in this study are collected with the CMS detector at the CERN LHC and correspond to an integrated luminosity of 35.9 fb(-1). The W+W- candidate events are selected by requiring two oppositely charged leptons (electrons or muons). Two methods for reducing background contributions are employed. In the first one, a sequence of requirements on kinematic quantities is applied allowing a measurement of the total production cross section, 117.6 +/- 6.8 pb, which agrees well with the theoretical prediction. Fiducial cross sections are also reported for events with zero or one jet, and the change in the zero-jet fiducial cross section with the jet transverse momentum threshold is measured. Normalized differential cross sections are reported within the fiducial region. A second method for suppressing background contributions employs two random forest classifiers. The analysis based on this method includes a measurement of the total production cross section and also a measurement of the normalized jet multiplicity distribution in W+W- events. Finally, a dilepton invariant mass distribution is used to probe for physics beyond the standard model in the context of an effective field theory, and constraints on the presence of dimension-6 operators are derived.
W+W− boson pair production in proton-proton collisions at sqrt(s)=13 TeV
Vagnerini, A.;Amapane, N.;Argiro, S.;Bellan, R.;Bellora, A.;Cappati, A.;Costa, M.;Covarelli, R.;Kiani, B.;Migliore, E.;Monaco, V.;Monteil, E.;Obertino, M. M.;Pacher, L.;Salvatico, R.;Siviero, F.;Sola, V.;Solano, A.;Soldi, D.;Shchelina, K.;Rumerio, P.;Ravera, F.;
2020-01-01
Abstract
A measurement of the W+W- boson pair production cross section in proton-proton collisions at sqrt(s) = 13 TeV is presented. The data used in this study are collected with the CMS detector at the CERN LHC and correspond to an integrated luminosity of 35.9 fb(-1). The W+W- candidate events are selected by requiring two oppositely charged leptons (electrons or muons). Two methods for reducing background contributions are employed. In the first one, a sequence of requirements on kinematic quantities is applied allowing a measurement of the total production cross section, 117.6 +/- 6.8 pb, which agrees well with the theoretical prediction. Fiducial cross sections are also reported for events with zero or one jet, and the change in the zero-jet fiducial cross section with the jet transverse momentum threshold is measured. Normalized differential cross sections are reported within the fiducial region. A second method for suppressing background contributions employs two random forest classifiers. The analysis based on this method includes a measurement of the total production cross section and also a measurement of the normalized jet multiplicity distribution in W+W- events. Finally, a dilepton invariant mass distribution is used to probe for physics beyond the standard model in the context of an effective field theory, and constraints on the presence of dimension-6 operators are derived.File | Dimensione | Formato | |
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2.PhysRevD.102.092001.pdf
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