  Several hadronic observables have been studied in central 158 A GeV Pb+Pb
collisions using data measured by the WA98 experiment at CERN: single negative
pion and kaon production, as well as two- and three-pion interferometry. The
Wiedemann-Heinz hydrodynamical model has been fitted to the pion spectrum,
giving an estimate of the temperature and transverse flow velocity.
Bose-Einstein correlations between two identified negative pions have been
analysed as a function of kT, using two different parameterizations. The
results indicate that the source does not have a strictly boost invariant
expansion or spend time in a long-lived intermediate phase. A comparison
between data and a hydrodynamical based simulation shows very good agreement
for the radii parameters as a function of kT. The pion phase-space density at
freeze-out has been measured and agrees well with the Tomasik-Heinz model. A
large pion chemical potential close to the condensation limit of the pion mass
seems to be excluded. The three-pion Bose-Einstein interferometry shows a
substantial contribution of the genuine three-pion correlation, but not quite
as large as expected for a fully chaotic and symmetric source.
