  Bose-Einstein (or HBT) momentum correlations reveal the space-time structure
of the particle emitting source created in high energy nucleus-nucleus
collisions. In this paper we present the latest NA61/SHINE measurements of
Bose-Einstein correlations of identified pion pairs and their description based
on Levy distributed sources in Be+Be collisions at 150A GeV/c. We investigate
the transverse mass dependence of the Levy source parameters and discuss their
possible interpretations.
