Direct extraction of transversity and its accompanying T-odd distribution from the unpolarized and single-polarized Drell-Yan processes

The Drell-Yan processes with unpolarized colliding hadrons and with the single transversally polarized hadron are considered. The possibility of direct (without any model assumptions) extraction of both transversity and its accompanying T-odd parton distribution functions is discussed. For Drell-Yan processes measurements planned at GSI, the preliminary estimations demonstrate that it is quite real to extract both transversity and its accompanying T-odd PDF in the PAX conditions.

Figure 1

Reconstructed from simulations (fixed target mode) quantities $\mu$ and $\nu$ versus $q_T$ in comparison with the input (corresponding to experimental data) dependencies (solid lines).

Figure 2

Reconstructed from simulations (fixed target mode) quantities $\mu$ and $\nu$ versus $x_1$ in comparison with the input (corresponding to experimental data) dependencies (solid lines).

Figure 3

$\widehat{k}$ versus $x_1$ at $x_F\simeq 0$. Data is obtained with Monte Carlo simulations for the collider mode (closed circles) and for the fixed target mode (open circles). For better visibility (to avoid overlapping), the points for the collider (fixed target) mode are shifted 0.01 to the left (right) along the $x$-axis.

Figure 4

$h_{1u}^{\perp (1)}$ versus $x_1$ at $x_F\simeq 0$. Data is obtained with Monte Carlo simulations for the collider mode (closed circles) and for the fixed target mode (open circles). For better visibility (to avoid overlapping), the points for the collider (fixed target) mode are shifted 0.01 to the left (right) along the $x$-axis.

Figure 5

SSA given by Eq. (20) versus $x_F$ for the collider mode for three values of $Q^2$: $50{\mathrm{GeV}}^2$ (lower curve), $25{\mathrm{GeV}}^2$ (middle curve), and $9{\mathrm{GeV}}^2$ (upper curve).

Figure 6

SSA given by Eq. (20) versus $x_F$ for the fixed target mode for three values of $Q^2$: $16{\mathrm{GeV}}^2$ (lower curve), $9{\mathrm{GeV}}^2$ (middle curve), and $4{\mathrm{GeV}}^2$ (upper curve).