Time-reversal odd fragmentation and distribution functions inppandepsingle spin asymmetries

We present some estimates of T-odd fragmentation and distribution functions, $H_1^{\perp }$ and $f_{1T}^{\perp },$ evaluated on the basis of a fit on experimental data in $p^{\uparrow }p.\mathrm{}$ Assuming the T-odd fragmentation function to be responsible for the single spin asymmetry in pion production in $p^{\uparrow }p,$ we find the ratio $H_1^{\perp }{/D}_1$ to be in good agreement with the experimental results from DELPHI data on $\overrightarrow{Z}2$-jet decay. We use our estimates to make predictions for ${\mathrm{ep}}^{\uparrow }.$