pdgLive

ACHARD 2004D study $WW-$pair production, single$-{{\mathit W}}$ production and single$-$photon production with missing energy from 189 to 209 GeV. The result quoted here is obtained using the $WW-$pair production sample. Each parameter is determined from a single$-$parameter fit in which the other parameters assume their Standard Model values.

SIRUNYAN 2020BA study electroweak production of a ${{\mathit W}}$ boson in association with two jets, using ${{\mathit W}}$ decays in the electron or muon channel. The isolated muons (electrons) are required to have a transverse momentum larger than 25 (30) GeV, while the transverse momentum of the two jets has to be larger than 50 and 30 GeV. A total of 2.382 (1.051) million events are selected in the muon (electron) channel, with a Standard Model expectation of $2.39$ $\pm0.17$ ($1.054$ $\pm0.058$) million events. Analysing the transverse momentum distribution of the charged leptons from ${{\mathit W}}$ decay, the following 95$\%$ C.L. limit is obtained: 0.956 $<$ ${{\mathit \kappa}_{{{Z}}}}$ $<$ 1.044. Combining this result with that from the closely-related electroweak ${{\mathit Z}}$-jet-jet production SIRUNYAN 2018BZ, the limit becomes: 0.957 $<$ ${{\mathit \kappa}_{{{Z}}}}$ $<$ 1.042.

SIRUNYAN 2019CL study ${{\mathit W}}{{\mathit W}}$ and ${{\mathit W}}{{\mathit Z}}$ production in lepton + jet events, with one ${{\mathit W}}$ boson decaying leptonically (electron or muon), and another ${{\mathit W}}$ or ${{\mathit Z}}$ boson decaying hadronically, reconstructed as a single massive large-radius jet. In the electron channel 2,456 (2,235) events are selected in the ${{\mathit W}}{{\mathit W}}({{\mathit W}}{{\mathit Z}}$) category, while in the muon channel 3,996 (3572) events are selected in the ${{\mathit W}}{{\mathit W}}({{\mathit W}}{{\mathit Z}}$) category. Analysing the di-boson invariant mass distribution, the following 95$\%$ C.L. limit is obtained: 0.9921 $<$ ${{\mathit \kappa}_{{{Z}}}}$ $<$ 1.0082.

⁴

AABOUD 2017S analyze electroweak production of a ${{\mathit W}}$ boson in association with two jets at high dijet invariant mass, with the ${{\mathit W}}$ boson decaying to electron or muon plus neutrino. In the signal region of dijet mass larger than 1 TeV and leading-jet transverse momentum larger than 600 GeV, 30 events are observed in the data with $39$ $\pm4$ events expected in the Standard Model, yielding the following limit at 95$\%$ CL for the form factor cut-off scale ${{\mathit \Lambda}_{{{FF}}}}\rightarrow\infty{}$: $0.85<{{\mathit \kappa}_{{{Z}}}}<1.16$.

⁵

KHACHATRYAN 2017O analyse ${{\mathit W}}{{\mathit Z}}$ production where each boson decays into electrons or muons. Events are required to have a tri-lepton invariant mass larger than 100 GeV, with one of the lepton pairs having an invariant mass within 20 GeV of the ${{\mathit Z}}$ boson mass. The ${{\mathit Z}}$ transverse momentum spectrum is analyzed to set a 95$\%$ C.L. limit of: $0.79$ $<$ ${{\mathit \kappa}_{{{Z}}}}$ $<$ $1.25$.

⁶

AAD 2016AR study ${{\mathit W}}{{\mathit W}}$ production in pp collisions and select 6636 WW candidates in decay modes with electrons or muons with an expected background of $1546$ $\pm157$ events. Assuming the LEP formulation and setting the form-factor $\Lambda $ to infinity, a fit to the transverse momentum distribution of the leading charged lepton, leads to a 95$\%$ C.L. range of 0.975 $<{{\mathit \kappa}_{{{Z}}}}<$ 1.020.

⁷

AAD 2016P study ${{\mathit W}}{{\mathit Z}}$ production in ${{\mathit p}}{{\mathit p}}$ collisions and select 2091 ${{\mathit W}}{{\mathit Z}}$ candidates in 4 decay modes with electrons and muons, with an expected background of $1825$ $\pm7$ events. Analyzing the ${{\mathit W}}{{\mathit Z}}$ transverse momentum distribution, the resulting 95$\%$ C.L. limit is: 0.81 $<{{\mathit \kappa}_{{{Z}}}}<$ 1.30.

⁸

AAD 2013AL study ${{\mathit W}}{{\mathit W}}$ production in ${{\mathit p}}{{\mathit p}}$ collisions and select 1325 ${{\mathit W}}{{\mathit W}}$ candidates in decay modes with electrons or muons with an expected background of $369$ $\pm61$ events. Assuming the LEP formulation and setting the form-factor ${{\mathit \Lambda}}$ = infinity, a fit to the transverse momentum distribution of the leading charged lepton, leads to a 95$\%$ C.L. range of 0.957 $<$ ${{\mathit \kappa}_{{{Z}}}}$ $<$ 1.043. Supersedes AAD 2012AC.

⁹

AAD 2012CD study ${{\mathit W}}{{\mathit Z}}$ production in ${{\mathit p}}{{\mathit p}}$ collisions and select 317 ${{\mathit W}}{{\mathit Z}}$ candidates in three ${{\mathit \ell}}{{\mathit \nu}}$ decay modes with an expected background of $68.0$ $\pm10.0$ events. The resulting 95$\%$ C.L. range is: 0.63 $<$ ${{\mathit \kappa}_{{{Z}}}}<$ 1.57. Supersedes AAD 2012V.

¹⁰

AALTONEN 2012AC study ${{\mathit W}}{{\mathit Z}}$ production in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions and select 63 ${{\mathit W}}{{\mathit Z}}$ candidates in three ${{\mathit \ell}}{{\mathit \nu}}$ decay modes with an expected background of $7.9$ $\pm1.0$ events. Based on the cross section and shape of the ${{\mathit Z}}$ transverse momentum spectrum, the following 95$\%$ C.L. range is reported: 0.61 $<$ ${{\mathit \kappa}_{{{Z}}}}$ $<$ 1.90 for a form factor of $\Lambda $ = 2 TeV.

¹¹

ABAZOV 2011 study the ${{\mathit p}}$ ${{\overline{\mathit p}}}$ $\rightarrow$ 3 ${{\mathit \ell}}{{\mathit \nu}}$ process arising in ${{\mathit W}}{{\mathit Z}}$ production. They observe 34 ${{\mathit W}}{{\mathit Z}}$ candidates with an estimated background of 6 events. An analysis of the $p_T$ spectrum of the ${{\mathit Z}}$ boson leads to a 95$\%$ C.L. limit of 0.600 $<{{\mathit \kappa}_{{{Z}}}}<$ 1.675, for a form factor $\Lambda $ = 2 TeV.

¹²

ABAZOV 2006H study ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit W}}{{\mathit W}}$ production with a subsequent decay ${{\mathit W}}$ ${{\mathit W}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit \nu}_{{{e}}}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}_{{{e}}}}$, ${{\mathit W}}$ ${{\mathit W}}$ $\rightarrow$ ${{\mathit e}^{\pm}}{{\mathit \nu}_{{{e}}}}{{\mathit \mu}^{\mp}}{{\mathit \nu}_{{{\mu}}}}$ or ${{\mathit W}}$ ${{\mathit W}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \nu}_{{{\mu}}}}{{\mathit \mu}^{-}}{{\overline{\mathit \nu}}_{{{\mu}}}}$. The 95$\%$ C.L. limit for a form factor scale $\Lambda $ = 2 TeV is $0.55$ $<\kappa _{Z}<$ 1.55, fixing $\lambda _{Z}$=0. With the assumption that the ${{\mathit W}}{{\mathit W}}{{\mathit \gamma}}$ and ${{\mathit W}}{{\mathit W}}{{\mathit Z}}$ couplings are equal the 95$\%$ C.L. one-dimensional limit ($\Lambda $ = 2 TeV) is $0.68$ $<\kappa <$ 1.45.

¹³

ABAZOV 2005S study ${{\overline{\mathit p}}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit W}}{{\mathit Z}}$ production with a subsequent trilepton decay to ${{\mathit \ell}}{{\mathit \nu}}{{\mathit \ell}^{\,'}}{{\overline{\mathit \ell}}^{\,'}}$ (${{\mathit \ell}}$ and ${{\mathit \ell}^{\,'}}$ = ${{\mathit e}}$ or ${{\mathit \mu}}$). Three events (estimated background $0.71$ $\pm0.08$ events) with $WZ$ decay characteristics are observed from which they derive limits on the anomalous couplings. The 95$\%$ CL limit for a form factor scale $\Lambda $ = 1 TeV is $-1.0$ $<$ ${{\mathit \kappa}_{{{Z}}}}$ $<$ 3.4, fixing ${{\mathit \lambda}_{{{Z}}}}$ and $\mathit g{}^{{{\mathit Z}}}_{1}$ to their Standard Model values.

References

Except where otherwise noted, content of the 2024 Review of Particle Physics is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) license. The publication of the Review of Particle Physics is supported by US DOE, MEXT (Japan), INFN (Italy) and CERN. Individual collaborators receive support for their PDG activities from their respective institutes or funding agencies. © 2024. See LBNL disclaimers.

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