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.
Measurement of Collins Asymmetries in the inclusive production of hadron pairs
GARZIA, Isabella
2010
Abstract
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.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.