  
|
     
|
The European Physical Journal C
ISSN: 1434-6044 (printed version)
ISSN: 1434-6052 (electronic version)
Abstract Volume 5 Issue 2 (1998) pp 239-248
DOI 10.1007/s100529800970
experimental physics:
Bose-Einstein correlations of three charged pions in hadronic Z$^{\bf 0}$ decays
The OPAL Collaboration
, K. Ackerstaff et al. (8)
(8) CERN, European Organisation for Particle Physics, CH-1211 Geneva 23, Switzerland
Received: 7 May 1998 / Published online: 12 August 1998
Abstract. Bose-Einstein Correlations (BEC) of three identical charged pions were studied in $4 \times 10^6$ hadronic ${\rm Z}^0$ decays recorded with the OPAL detector at LEP. The genuine three-pion correlations, corrected for the Coulomb effect, were separated from the known two-pion correlations by a new subtraction procedure. A significant genuine three-pion BEC enhancement near threshold was observed having an emitter source radius of $r_3 = 0.580 \pm 0.004 \mbox{ (stat.)} \pm 0.029 \mbox{ (syst.)} \mbox{ fm}$ and a strength of $\lambda_3 = 0.504 \pm 0.010 \mbox{ (stat.)}\pm 0.041 \mbox{ (syst.)}$. The Coulomb correction was found to increase the $\lambda_3$ value by $\sim $9% and to reduce $r_3$ by $\sim $6%. The measured $\lambda_3$ corresponds to a value of $0.707 \pm 0.014 \mbox{ (stat.)} \pm 0.078 \mbox{ (syst.)}$ when one takes into account the three-pion sample purity. A relation between the two-pion and the three-pion source parameters is discussed.
Article in PDF-Format (405 KB)
Article in (gzipped) PS-Format (237 KB)
Online publication: August 25, 1998
LINK Helpdesk
© Springer-Verlag Berlin Heidelberg 1998