Transversity distribution describes the quark transverse polarization inside a transversely polarized nucleon. It 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 (SIDIS) 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- -> qqbar -> pi pi X, where the two pions are produced in opposite hemispheres, based on a data sample collected by the BaBar experiment at a center-of-mass energy of about 10.6 GeV. The Collins function is extracted from the measured asymmetries.
Measurement of Collins asymmetries in inclusive production of pionn pairs in electron-positron collision at BaBar
GARZIA, Isabella
2011
Abstract
Transversity distribution describes the quark transverse polarization inside a transversely polarized nucleon. It 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 (SIDIS) 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- -> qqbar -> pi pi X, where the two pions are produced in opposite hemispheres, based on a data sample collected by the BaBar experiment at a center-of-mass energy of about 10.6 GeV. 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.
