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Charged hadron production ine + e − annihilation in the Υ and Υ′ region |
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| Authors: | B. Niczyporuk T. Zeludziewicz K. W. Chen R. Hartung G. Folger B. Lurz H. Vogel U. Volland H. Wegener J. K. Bienlein R. Graumann J. Krüger M. Leißner M. Schmitz F. H. Heimlich R. Nernst A. Schwarz U. Strohbusch H. -J. Trost P. Zschorsch A. Engler R. W. Kraemer F. Messing C. Rippich B. Stacey S. Youssef A. Fridman G. Alexander A. Av-Shalom G. Bella Y. Gnat J. Grunhaus E. Hörber W. Langguth M. Scheer LENA Collaboration |
| Affiliation: | 1. Institute of Nuclear Physics, Cracow, Poland 2. Department of Physics, Michigan State University, East Lansing, MI, USA 4. Physikalisches Institut der Universit?t Erlangen-Nürnberg, D-8520, Erlangen, Germany 6. Deutsches Elektronen-Synchrotron DESY, D-2000, Hamburg, Germany 7. I. Institut für Experimentalphysik der Universit?t, D-2000, Hamburg, Germany 8. Department of Physics, Carnegie-Mellon University, Pittsburgh, PA, USA 9. Département de Physique de Particules Elémentaires, CEN-Saclay, F-91190, Gif-sur-Yvette, France 10. Department of Physics and Astronomy, Tel-Aviv University, Israel 11. Physikalisches Institut der Universit?t Würzburg, D-8700, Würzburg, Germany |
| Abstract: | Charged hadron production ine + e ? annihilation is studied in the 7 to 10 GeV CM energy region and at the Υ (9.46) and Υ′ (10.01) resonances with the LENA detector at DORIS. The statistical moments of the charged multiplicities are studied. The data show KNO scaling behaviour and suggest the presence of long range correlations. An average charged multiplicityrise of Δn(Υ)=0.55±0.19 and Δn(Υ′)=1.26±0.29 over the continuum is observed for the Υ and Υ′ direct decays. The jet structure of the Υ and Υ′ direct decays is investigated using the charged particles. The polar angular distributions of the jet axis behave like 1+α(T) cos2θ with 〈α(T)〉Υ=0.7±0.3 and 〈α(T)〉Υ′=0.6±0.4. The 〈α(T)〉Υ value is in agreement with the QCD vector gluon assignment and excludes scalar gluons by more than four standard deviations. |
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