Ratios of D-meson production cross sections as a function of $\pt$ Predictions from FONLL, GM-VFNS and LO $\kt$-factorisation calculationsare also shown. For the pQCD calculations the line shows the ratio ofthe central values of the theoretical cross sections, while the shaded area isdefined by the ratios computed from the upper and lower limits of thetheoretical uncertainty band. | |