On the T-odd Quark Fragmentation Function

The first probe of the correlation of the T-odd one-particle fragmentation function responsible for the left--right asymmetry of fragmentation of a transversely polarized quark and an antiquark is done by using the 1991-95 DELPHI data for Z → 2 jet decay. Integrated over the fraction of longitudinal and transverse momenta, this correlation is up to 16 ppm order, which means order of 13% for the analysing power. This makes us hope to use this effect in polarized DIS experiments for transversity measurement