Eur. Phys. J. C

**21**, 23-32 (2001)

DOI: 10.1007/s100520100715

## Bose-Einstein correlations in
pairs
from
Z^{0} decays into two hadronic jets

**The OPAL Collaboration G. Abbiendi and et al.**

Dipartimento di Fisica dell' Università di Bologna and INFN, 40126 Bologna, Italy

(Received: 19 November 1999 / Published online: 6 July 2001 -© Springer-Verlag / Società Italiana di Fisica 2001)

** Abstract **

Bose-Einstein correlations in pairs of charged kaons
produced in a sample of 3.9 million hadronic
Z^{0}
decays have been measured with the OPAL experiment at LEP. Charged
kaons were identified in the central tracking
detector using their specific energy loss in the drift chamber gas.
The correlation function was studied in two-jet events using
a double ratio, formed by the number of like-sign pairs normalised
by a reference sample in the data,
divided by the same ratio in a Monte Carlo simulation. The enhancement
at small values of the four-momentum difference of the pair was parametrised
using a Gaussian function. The parameters of the Bose-Einstein
correlations were measured to be =
for
the strength and
fm for the kaon source
radius, where the first errors are statistical and the second
systematic. Corrections for final-state interactions are discussed.

**©**

*Società Italiana di Fisica, Springer-Verlag 2001*