Measurement of Collins Asymmetries in the inclusive production of hadron pairs

Transversity Distribution, which describes the quark transverse polarization inside a transversely polarized nucleon, is the last leading-twist missing piece of the QCD description of the partonic structure of the nucleon. Transversity can be extracted from semi-inclusive deep inelastic scattering data, where, however, it couples to a new, unknown fragmentation function, called Collins function. We present a measurement of the azimuthal asymmetries in the process e+e? -> X (inclusive hadron production), in which the two pions are produced in opposite hemispheres, based on the full BABAR data sample. The Collins function is extracted from the measured asymmetries