Transversity distribution describes the quark transverse polarization inside a transversely polarized nucleon. It is the less known leading-twist piece of the QCD description of the partonic structure of the nucleon. Transversity can be extracted from semi-inclusive deep inelastic scattering (SIDIS) where, however, it couples to a new, unknown fragmentation function, called Collins function. We present the preliminary results of the measurement of the azimuthal asymmetries in the process e+e- → qq → φφX, where the two pions are produced in opposite hemispheres. These preliminary results are based on a data sample of about 45 fb-1, collected by the BABAR experiment at a center-of-mass energy of 10.54GeV, and are compared with the Belle measurements. © Societa Italiana di Fisica.
Study of Collins asymmetries at BaBar
GARZIA, Isabella
2012
Abstract
Transversity distribution describes the quark transverse polarization inside a transversely polarized nucleon. It is the less known leading-twist piece of the QCD description of the partonic structure of the nucleon. Transversity can be extracted from semi-inclusive deep inelastic scattering (SIDIS) where, however, it couples to a new, unknown fragmentation function, called Collins function. We present the preliminary results of the measurement of the azimuthal asymmetries in the process e+e- → qq → φφX, where the two pions are produced in opposite hemispheres. These preliminary results are based on a data sample of about 45 fb-1, collected by the BABAR experiment at a center-of-mass energy of 10.54GeV, and are compared with the Belle measurements. © Societa Italiana di Fisica.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.