Measuring the space-time extent of nuclear collisions using interferometry

Hanbury-Brown and Twiss (HBT) interferometry is used to study the space-time evolution of nuclear collisions at CERN energies. Pairs of identified pions, kaons and protons are studied by NA44 for a variety of collisions systems ranging from p-Pb to Pb-Pb. The pion and kaon correlation data from the 1994 and 1995 Pb runs are compared to published data. The systematic increase in radius parameter with system size is continued in the Pb data sample. Model comparison stress the importance of scattering in the evolution of the collision.