2020 Impact factor 4.590
Particles and Fields
Eur. Phys. J. C16, 445-451
DOI 10.1007/s100520000413

Central Pb+Pb collisions at 158 A GeV/c studied by $\pi^-\pi^-$ interferometry

The WA98 Collaboration
M.M. Aggarwal1 - et al.

1 University of Panjab, Chandigarh 160014, India

Received: 3 February 2000 / Published online: 18 May 2000 - © Springer-Verlag 2000

Two-particle correlations have been measured for identified $\pi^-$ from central 158 A GeV Pb+Pb collisions and fitted radii of about 7 fm in all dimensions have been obtained. A multi-dimensional study of the radii as a function of kT is presented, including a full correction for the resolution effects of the apparatus. The cross term R2out-long of the standard fit in the Longitudinally CoMoving System (LCMS) and the vL parameter of the generalised Yano-Koonin fit are compatible with 0, suggesting that the source undergoes a boost invariant expansion.
The shapes of the correlation functions in Qinv and $Q_{space}=\sqrt{Q^2_x+Q^2_y+Q^2_z}$ have been analyzed in detail. They are not Gaussian but better represented by exponentials. As a consequence, fitting Gaussians to these correlation functions may produce different radii depending on the acceptance of the experimental setup used for the measurement.

Copyright Società Italiana di Fisica, Springer-Verlag 2000