Direct Measurement of Leptonic Coupling Asymmetries with PolarizedZBosons

Abe K ,J Ma,M Dima,M Kalelkar,R Verdier,Ximeng Yang ,P.y.c Du ,D Dong ,J Wyss,G M Bilei,C Simopoulos,S Willocq,J R Johnson,H Hwang,David Jeff Jackson ,M Hildreth ,M Woods,J A Coller,D J Sherden,A K Mckemey,P G Verdini,T W Reeves,I Karliner,A I Trandafir,T H Burnett,A Lu,P L Reinertsen,T Pavel ,M King ,A Calcaterra,Y Hasegawa,M Langston,X Liu,F J Wickens,D Calloway,G Zapalac,M Cavalli‐Sforza ,M Loreti,G Gladding,B I Eisenstein,P Rensing ,T Bolton,R Elia,H Kawahara,S Hedges ,M Carpinelli,J A Jaros,R Dubois,J P Fernandez,Hyejoo Kang ,D L Burke ,J L Harton,D Onoprienko,W Busza,T Schalk,H Yuta,E Torrence,S Suzuki,R S B King ,R Kroeger ,E Church,R De Sangro,R Cassell,J Lauber ,W J Wisniewski,T W Markiewicz,R Prepost,G Mantovani,A Sugiyama,M.e Huffer ,A C Benvenuti,D L Wagner,E Vella,Philip Burrows ,R Cotton,R Kajikawa,F Taylor ,Brett Bolen ,C H Park,R S Panvini,D O Caldwell,H.w Kendall ,J S Whitaker,T Nagamine,Y Ohnishi,P Stamer,A Johnson ,P C Rowson,J D Turk,M.h Shaevitz ,J Schwiening,J P Venuti,G L Bashindzhagyan,W W Ash,K Shmakov ,R Castaldi,J Reidy,J T Shank,L.s Rochester ,A Chou,L S Osborne,E Pieroni,S Fahey,A O Bazarko,K Furuno,Y Iwasaki,J R Bogart,S González ,J Zhou,V Lia,R Cowan ,H R Band,K Pitts ,J A Snyder,G Crawford,M Piccolo,J Quigley,S Williams ,R Dell’orso ,K C Moffeit,N.j Allen ,M Daoudi,J M Yamartino,M G Strauss,D Falciai,G Mancinelli,H Neal,C Damerell ,S Narita,R Kofler ,Daniel C Williams ,G D Punkar,D Aston,D R Müller ,R Frey,P Mockett ,T R Junk ,E L Hart,D Su,C Young ,E Mazzucato,J Huber,U Nauenberg,T Barklow ,M Breidenbach,Asier Pereiro Castro ,C Vannini,N B Sinev,G B Word,R A Johnson,M X Liu,R Steiner,J Va’vra ,K Hasuko,R H Schindler,A Szumilo,J Brau ,P Dervan ,G Blaylock,A W Weidemann,C Baltay,R Messner,S Yellin ,H Park,M B Barakat,L Piemontese,O Bardon,V Cook,T Gillman,D W G S Leith,G R Bower,J Yashima,R J Plano,Hiroaki Masuda ,S L White,B A Schumm,A Lath,S Manly,Tohru Takahashi ,C Fan,F Suekane,M Smy ,Sutapa Sen ,R W Zdarko,T Usher,E W Hughes,T B Moore,B Camanzi,Y D Kim,H Steiner,E R Weiss,Z Jiang ,V.v Serbo ,T Maruyama,G Baranko,S R Smith,R Ben‐David ,R Wilson ,J J Russell,P Jacques,M Nussbaum,K Baird ,N.m Krishna ,T Akagi,R K Yamamoto,D Bisello,S S Hertzbach,O H Saxton,H O Cohn,S Watts ,A Hasan,A D’oliveira ,I Peruzzi,M Swartz,M J Fero,S.r Wagner ,D G Coyne,C Y Prescott,W Bugg ,D A Williams,B Meadows ,J F Labs,H L Lynch,A P Waite,G Shapiro,E Etzion,B N Ratcliff

doi:10.1103/physrevlett.79.804

Abstract

We present direct measurements of the Z{sup 0} -lepton coupling asymmetry parameters A{sub e} , A{sub {mu}} , and A{sub {tau}} , based on a data sample of 12063leptonic Z{sup 0} decays collected by the SLD detector. The Z bosons are produced in collisions of beams of polarized e{sup {minus}} with unpolarized e{sup +} at the SLAC Linear Collider. The couplings are extracted from the measurement of the left-right and forward-backward asymmetries for each lepton species. The results are A{sub e}=0.152{plus_minus}0.012(stat) {plus_minus}0.001(syst) , A{sub {mu}}=0.102{plus_minus}0.034{plus_minus}0.002 , and A{sub {tau}}=0.195{plus_minus}0.034{plus_minus}0.003 . {copyright} {ital 1997} {ital The American Physical Society}

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