MEASUREMENT OF a . FROM HADRONIC EVENT OBSERVABLE AT THE 2 ° Kenneth

We have measured the strong coupEng a~(~~) using hadronic decays of 2° bosons coHected by the SLD experiment at SLAC. The data were compared with QCD predictions both at fied order O(a~ ) and including resummed ana~~~ lytic fomdae based on the next-to-leading logarithm approximation. We have performed a comprehensive analysis using event shapes, jet rates, particle correlations, and angtiar energy flows, and have checked the consistency between ag(~~ ) values extracted from these different measures. Combining these resdts we obtain a~(~~) = 0.1200A 0.0025 (exp.) iO.0078(theor.) , where the dominant uncertainty is from uncdcdated higher order contributions. We have dso compared a recent cdctiation by Clay and Ems of energy-energy correlations (EEC) and the asymmetry (AEEC) with our data. We fid that the a~(~j) value obtained for the ~~c is si@cantly lower than that obtained from comparable fits using the O(a~ ) cdcdation of Kunszt md Nason. Presented at the XXXth Rencontres de Moriond: QCD and High-Energy Hadronic Interactions, Les Arcs, France, March 19-26, 1995 ‘*Members of the SLD Co~aboration are Hsted fo~owing the fist of references. *This work was supported by Department of Energy contracts: DEFG02-91ER40676 (BU), DEFG03-92ER40701 (CIT), DEFG03-91ER40618 (UCSB), DEFG03-92ER40689 (UCSC), DE FG03-93ER40788 (CSU), DEFG02-91ER40672 (Colorado), DEFG02-91ER40677 (~nois), DE AC03-76SFOO098 (LBL), DEFG02-92ER40715 (Massachusetts), DEAC02-76ER03069 (MIT), DEFG06-85ER40224 (Oregon), DWAC03-76SFO0515 (SLAC), DEFG05-91ER40627 (Tennessee), DEAC02-76ERO0881 (Wisconsin), DE FG02-92ER40704 (Yale); National Science Foundation grants: PHY-91-13428 (UCSC), PHY-89-21320 (Columbia), PHY-92-04239 (Cincinnati), PHY-88-17930 (Rutgers), PHY-88-19316 (Vanderbdt), PHY-92-03212 (W~hington); the UK Science and Engineering Research Councfl (Brunei_ andRAL); the Istituto Nazionale di Fisica Nucleare of Italy (Bologna, Ferrara, Fr=cati, Pisa, Padova, Perugia); and the Japan-US Cooperative Research Project on High Energy Physics (Nagoya, Tohoku).