Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published July 2001 | Published + Submitted
Journal Article Open

Multiplicity of charged and neutral pions in deep-inelastic scattering of 27.5 GeV positrons on hydrogen


Measurements of the individual multiplicities of π^+, π^− and π^0 produced in the deep-inelastic scattering of 27.5 GeV positrons on hydrogen are presented. The average charged pion multiplicity is the same as for neutral pions, up to z≈0.7, where z is the fraction of the energy transferred in the scattering process carried by the pion. This result (below z≈0.7) is consistent with isospin invariance. The total energy fraction associated with charged and neutral pions is 0.51±0.01(stat.)±0.08 (syst.) and 0.26±0.01(stat.)±0.04(syst.), respectively. For fixed z, the measured multiplicities depend on both the negative squared four momentum transfer Q^2 and the Bjorken variable x. The observed dependence on Q^2 agrees qualitatively with the expected behaviour based on NLO-QCD evolution, while the dependence on x is consistent with that of previous data after corrections have been made for the expected Q^2 -dependence.

Additional Information

© 2001 Springer-Verlag Berlin Heidelberg / Società Italiana di Fisica. Received: 2 April 2001; Revised version: 27 June 2001; Published online: 7 September. We thank M. Greco, G. Kramer, and B. Pötter for useful discussions on fragmentation functions. We gratefully acknowledge the DESY management for its support and the staffs at DESY and the collaborating institutions for their significant effort. This work was supported by the Fund for Scientific Research-Flanders (FWO) of Belgium; the Natural Sciences and Engineering Research Council of Canada; the INTAS, HCM and TMR contributions from the European Community; the German Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie (BMBF), the Deutscher Akademischer Austauschdienst (DAAD); the Italian Istituto Nazionale di Fisica Nucleare (INFN); Monbusho, JSPS, and Toray Science Foundation of Japan; the Dutch Stichting voor Fundamenteel Onderzoek der Materie (FOM); the UK Particle Physics and Astronomy Research Council; and the US Department of Energy and National Science Foundation.

Attached Files

Published - art_3A10.1007_2Fs100520100765.pdf

Submitted - 0104004.pdf


Files (464.5 kB)
Name Size Download all
227.8 kB Preview Download
236.7 kB Preview Download

Additional details

August 19, 2023
October 25, 2023