ÚTEFČVUT Ústav technické a experimentální fyziky ČVUT v PrazeInstitute of Experimental and Applied Physics, CTU in Prague

Studies of the Energy Dependence of Diboson Polarization Fractions and the Radiation-Amplitude-Zero Effect in WZ Production with the ATLAS Detector

NázevTitle
Studies of the Energy Dependence of Diboson Polarization Fractions and the Radiation-Amplitude-Zero Effect in WZ Production with the ATLAS DetectorStudies of the Energy Dependence of Diboson Polarization Fractions and the Radiation-Amplitude-Zero Effect in WZ Production with the ATLAS Detector
Druh výsledkuResult type
Článek v časopiseJournal article
AutořiAuthors
G. Aad, E. Aakvaag, B. Abbott, K. Abeling, B. Ali, K. Augsten, B. Bergmann, H. Day-Hall, P. Fiedler, Z. Hubáček, P. Jačka, S. Mondal, M. Myška, L. Novotný, V. Petousis, S. Pospíšil, K. Smolek, A. Sopczak, V. Vacek, P. Vokáč, O. Zaplatílek
Klíčová slovaKeywords
Diboson polarization, longitudinally polarized bosons, radiation-amplitude-zero effect
ExperimentCollaboration
ATLAS
DOIDOI
10.1103/PhysRevLett.133.101802
Časopis / citaceJournal / citation
Physical Review Letters 133(10), 101802 (2024) · ISSN 0031-9007
RokYear
2024
JazykLanguage
eng
ZáznamyRecords
ProjektProject
Institucionální podpora na rozvoj výzkumné org.Institucionální podpora na rozvoj výzkumné org.; Institucionální podpora na rozvoj výzkumné org.Institucionální podpora na rozvoj výzkumné org.; Výzkum základních stavebních kamenů hmoty s využitím špičkových technologiíFundamental constituents of matter through frontier technologies; CERN-CZ III - Výzkumná infrastruktura pro experimenty v CERN - LM2023040 (2023–2026)CERN-CZ III - Výzkumná infrastruktura pro experimenty v CERN - LM2023040 (2023–2026)
CitovánoCited by
38 (INSPIRE-HEP)
2024: 152025: 132026: 10
Citace ke staženíDownload citation
TXT · BibTeX

AbstraktAbstract

This Letter presents the first study of the energy dependence of diboson polarization fractions in WZ→ℓνℓ^{'}ℓ^{'}(ℓ,ℓ^{'}=e,μ) production. The dataset used corresponds to an integrated luminosity of 140 fb^{-1} of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector. Two fiducial regions with an enhanced presence of events featuring two longitudinally polarized bosons are defined. A nonzero fraction of events with two longitudinally polarized bosons is measured with an observed significance of 5.3 standard deviations in the region with 100[removed]200 GeV, where p_{T}^{Z} is the transverse momentum of the Z boson. This Letter also reports the first study of the radiation-amplitude-zero effect. Events with two transversely polarized bosons are analyzed for the ΔY(ℓ_{W}Z) and ΔY(WZ) distributions defined respectively as the rapidity difference between the lepton from the W boson decay and the Z boson and the rapidity difference between the W boson and the Z boson. Significant suppression of events near zero is observed in both distributions. Unfolded ΔY(ℓ_{W}Z) and ΔY(WZ) distributions are also measured and compared to theoretical predictions.

This Letter presents the first study of the energy dependence of diboson polarization fractions in WZ→ℓνℓ^{'}ℓ^{'}(ℓ,ℓ^{'}=e,μ) production. The dataset used corresponds to an integrated luminosity of 140 fb^{-1} of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector. Two fiducial regions with an enhanced presence of events featuring two longitudinally polarized bosons are defined. A nonzero fraction of events with two longitudinally polarized bosons is measured with an observed significance of 5.3 standard deviations in the region with 100[removed]200 GeV, where p_{T}^{Z} is the transverse momentum of the Z boson. This Letter also reports the first study of the radiation-amplitude-zero effect. Events with two transversely polarized bosons are analyzed for the ΔY(ℓ_{W}Z) and ΔY(WZ) distributions defined respectively as the rapidity difference between the lepton from the W boson decay and the Z boson and the rapidity difference between the W boson and the Z boson. Significant suppression of events near zero is observed in both distributions. Unfolded ΔY(ℓ_{W}Z) and ΔY(WZ) distributions are also measured and compared to theoretical predictions.

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