6533b858fe1ef96bd12b5858

RESEARCH PRODUCT

Study of the leptonic decays of the Z0 boson

A. KlovningU. MjoernmarkSandor CzellarG. PolokM. BozzoV.a. UvarovA. RuizUgo GaspariniPaolo PasiniP. QueruW. K. Van DoninckW. K. Van DoninckF. RichardC. MatteuzziM. HahnB. BouqquetA. G. FrodesenAndrey KorytovJan KrolikowskiN. N. KhovanskiW. BartlB. V. BatyuniaR. PainB. KoeneE. LiebA. SebastiaI. LippiE.n. TsyganovJ. H. WickensJ. H. WickensJose Luis ContrerasC. Vander VeldeC. Vander VeldeC. LambropoulosUgo AmaldiE. ZevgolatakosR. RongvedS. AlmehedC. PinoriJ. P. LaugierJ.a.m.a. BuytaertJ.a.m.a. BuytaertA.n. DiddensU. Kruener-marquisM. GorbicsJ.a. LidburyD. RadojicicJ.p. GrilletM. PimentaN. De GrootM. De BeerG. WormserAriella CattaiJacques LemonneJacques LemonneA. StocchiGuido BarbielliniGuido BarbielliniM. PernickaG. LenzenJ. E. CampagneM. KoratzinosL. GuglielmiM. BonapartWolfgang AdamD. BertrandD. BertrandFrancesco NavarriaPaolo MorettiniJ. G. LokenJ.f. GenatB. KisielewskiPaolo RoncheseT. KreuzbergerJ.c. RaoulG. GoujonG. CrosettiEvgueni VlasovM. NigroJan RidkyA. S. VodopianovTuure TuuvaClara TronconItzhak RoditiGueorgui ChelkovJ. GuyB. DalmagneM. KopfJ. N. JacksonP. KokkiniasM. PasseneauS. FerroniZ. HajdukF. UdoG. PetrucciM. NordbergR. LauhakangasH. HerrWinfried MitaroffP. BeltranLouis LyonsC.w. SalgadoJ. MasP. LutzG. TristramP. LaurikainenS. DuPaula EerolaO. UllalandF. DjamaC. GasparS. HaiderD.n. EdwardsC. CasoM. SessaM. SessaV. Castillo GimenezP. NegriTim AdyeC. De La VaissiereLaurent ChevalierU. TrevisanN. CroslandJ.v. AllabyM. JonkerY. SacquinMaciej GórskiA. B. FenyukL. MattssonJ.j. JaegerTiziano RovelliM. CrestiJ.h. BibbyG.p. BarreiraB. Lund-jensenG. E. KalmusG. D. AlekseevJ. M. YeltonA. PasseriS. GawneKlaus HamacherA. FirestoneG. KantardjianC. De ClercoC. De ClercoMilos LokajicekK. WoschnaggM. NonniP. BranchiniJ. KrsticGöran JarlskogW. BellN. I. ZiminStavros MaltezosMikael BerggrenH. HofmannJ. Cuevas MaestroH. B. CrawleyV. LepeltierH. ForsbachF. Fulda-quenzerT. BologneseE. C. KatsoufisG. GopalA. Letessier-selvonS. GumenyukNikolai SmirnovV. RuhlmannO. BarringG. ZhangPaolo ChecchiaB. FranekW. KucewiczG. MatthiaeC. StanescuL.j. CarrollM. L. TurluerM. VollmerD. ReidPh. GavilletP. SpentzourisE. GrazianiB. Jean-marieA. HakanssonE. J. SanchezW. D. ApelS. J. AlvsvaagRoland HorisbergerL. BuggeG. Hamel De MonchenaultE. G. AnassontzisJ. P. EngelI. KontaxisP. LorenzP. RoudeauM. J. BatesEdoardo CastelliEdoardo CastelliD. Z. ToetJ. JoensuuJ. M. BrunetH. LebboloJosef StraussR. LlosaN. BingeforsP. Van DamM. Fernandez AlonsoP. PriviteraM.v. ReisP. WeilhammerLuc PapeD. ImbaultR. ZitounD. LangerveldP. AbreuP. BorgeaudBorge Svane NielsenM. H. GrosF. J. HarrisH. FoethP. AllenGianni ZumerleF. AstesanToralf Bernhard SkaaliMaria Roberta MongeS. BarlagA. ZalewskaValery PozdnyakovG. CabrasG. CabrasKrzysztof DorobaChiara MeroniA.k. ToppholC. BrandM. Mc CubbinG. EkspongK. HultqvistRenato TurchettaB. GrosseteteAllan HallgrenB. KorzenP. PoropatP. PoropatG. DamgaardC. PoiretC. PoiretL. TortoraGiovanni ValentiI. BelokopytovM. BoratavD. GambaG. VoulgarisSverker JohanssonW. T. MeyerPierre BilloirMogens DamK. RybickiW. VenusB. MurynV. ObraztsovP. AarnioV. GraccoM. SchaefferAndre AugustinusP. HerquetP. HerquetH. PalkaG. SkjevlingR. ContriGiovanni DarboS. SimonettiM. VoutilainenG. GrosdidierR. SekulinR. DzhelyadinT. PettersenJose M. BenllochA. GrantR.b. KadyrovF. BaraoP. V. ChliapnikovM. CrozonCraig ButtarA. De AngelisA. De AngelisD. DelikarisN. Van EijndhovenJ. WernerL. Viseu MeloE. SundellM.i. LaaksoDaniel BlochHans DijkstraI. HerbstKatri HuituT.k. TruongB. GoretM. BaubillierR. LucockAlessandra RomeroGeorgios StavropoulosJ.m. NoppeM. TuralaBarry KingAhmimed OuraouPavlos IoannouF. SimonettoR. GokieliA. TilquinJ. PerezI.a. GritsaenkoG. LederG. B. ChadwickE. HigonR. SeufertV.m. GolovatyukW.s.c. WilliamsDaniel TreilleJ. J. HernandezR. FrühwirthManolis DrisJ. PyythiaB. ÅSmanP. AdrianosC. J. BeestonF. ScuriF. ScuriJuan FusterN.k. VishnevskijA. M. ZaitsevE. K. JohanssonJ. E. HooperJ.c. Le GrandJ. TimmermansJ. PagotA. PulliaJ.-e. AugustinA. M. WetherellE. LillethunT. MoaG. MaehlumK. PakonskiF. BianchiJ. MichałowskiKjell FranssonL. LanceriL. LanceriD. HussonJ. BarlowE. VelaLucio CerritoT. BuranJ.b.m. PattisonI. A. TyapkinM. A. HouldenD. CrennellF. MandlA. PinsentA.m. RomayaM. EllilaGuenakh MitselmakherA.j. Camacho RozasD. VilanovaG. SmadjaD.yu. BarbinS. SquarciaK. W. GlitzaA. ZinchenkoE. MenichettiOlga BotnerKrzysztof KorcylH. SaarikkoT. HofmoklMarek SzczekowskiN. DimitriouStefano RagazziJosé SaltF. CouchotR. SosnowskiB. W. HeckE. RossoH. KleinH. SchneiderV. G. TimofeevS. NounosJ.-p. VanuxemPanos KostarakisM.-h. GrosA. MarkouF. CaoF. CaoV. FalaleevE. LillestolV. ChorowiczO.a. MaelandR. DownsJ. HaissinskiS. BraibantTord EkelofH. StaeckG. GaleazziR. StrubB. LoerstadK. MoenigS. CairantiH. BurmeisterD. SaccoM. MazzucatoE. FokitisRobert S. BrownJ. DreesP. SzymanskiPatrick JarryM. WinterG. RinaudoEvangelos GazisG. VegniN. BrummerW. H. RangeE. SpiritiB.d. HyamsE. I. RosenbergK. KurvinenM. DracosR. RagazzonR. RagazzonP. SiegristJ-c. MarinM. DavenportB. GrungA. A. RademakersS. O. HolmgrenD. BenedicD. LoukasGeorge KalkanisP. B. RentonM. FlinnL. O. EekR. C. ShellardL. Di CiaccioJosef HrubecA. M. SegarD. C. FriesG. KuhnP. S. IversenF. FontanelliJ. SkeensC. Astor FerreresJ. VelascoMarta CalviL. TkachevVincenzo CanaleGeoffrey SmithG. W. Van ApeldoornG. SetteL.s. CurwenW. DulinskiL. VenturaHåkan T JohanssonB. LavigneS. Palma LopesS. QuintonHans MullerT. OdegaardP. N. BogolubovChristine KourkoumelisE. Dahl-jensenH. De BoeckM. TyndelP. VazD. BolliniM. PegoraroJ. MaillardP. JalochaS. BiagiH. P. BornerV. KadyshevskiyV. PerevozchikovTheodora PapadopoulouTiziano CamporesiN. G. RedaelliP. FrenkielR. MoellerA. BaroncelliA. HrisohoH. J. HilkeC. BosioF. WaldnerF. WaldnerK. D. BrandAntonio FerrerRoberto CirioL. K. ResvanisC. WalckG. E. TheodosiouM. ZitoO. PingotO. PingotK. SpangE. SanchisL. MathisMassimo CacciaN. YamdagniPaul BaillonAlexander Lincoln ReadVladimir NikolaenkoM. SzeptyckaP. JuillotM. MurM.a. Lopez AgueraFrancesca Romana CavalloMitchell WayneV. V. LapinP. O. HulthF. RosselP. DelpierreE. DaubieE. DaubieG. MyattJ.m. GagoJoao VarelaP. KluitP. KluitP. R. S. GomesS. UeberschaerA. MaltezosM. GaillardA. CampionR. Zukanovich FunchalH. WahlenAriel GoobarD. FraissardK. H. BecksP. AntilogusM. E. VeitchJ. BjarneW. KlemptF. HahnF. StichelbautF. StichelbautR. Mc KayCesare ChiccoliF. AdamiM. Barranco-luqueR. KeranenPhilippe CharpentierMario SanninoR. OravaS. Topp-jorgensenMaria Elena PolS. KatsanevasT. A. FilippasM. ReglerYu. SedykhB. Van EijkH. MuellerJ. DolbeauP. FolegatiP.s.l. BoothP. N. RatoffJ. J. Gómez CadenasJ. MarcoM. P. ClaraPiotr Zalewski

subject

PhysicsNuclear and High Energy PhysicsParticle physics[PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex]010308 nuclear & particles physicsElectron–positron annihilationHadronWidth ratio01 natural sciences7. Clean energyNuclear physics0103 physical sciencesPhysique des particules élémentaires[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Neutrino010306 general physicsParticle Physics - ExperimentLeptonBoson

description

Measurements are presented of the cross section ratios Rℓ = σℓ(e+e-→ℓ+ℓ -)/σhh(e+e-→hadrons) for ℓ = e, μ and τ using data taken from a scan around the Z0. The results are Re = (5.09±0.32±0.18)%, Rμ = (4.96±0.35±0.17)% and Rτ,=(4.72±0.38± 0.29)% where, for the ratio Re, the t-channel contribution has been subtracted. These results are consistent with the hypothesis of lepton universality and test this hypothesis at the energy scale s ∼ 8300 GeV2. The absolute cross sections σℓ(e+e-→ℓ +ℓ-) have also been measured. From the cross sections the leptonic partial widths Γe = (83.2±3.0±2.4) MeV, (ΓeΓμ) 1/2=(84.6±3.0±2.4) MeV and (ΓeΓτ) 1/2=(82.6±3.3±3.2) MeV have been extracted. Assuming lepton universality the ratio Γℓ/Γh=(4.89±0.20± 0.12) × 10-2 was obtained, together with Γℓ=(83.6±1.8±2.2) MeV. The number of light neutrino species is determined to be Nv=3.12±0.24±0.25. Al the data are consistent with the predictions of the standard model.

https://doi.org/10.1016/0370-2693(90)91667-z