Constraints for nuclear gluon densities from DIS data

Original · EN

The Q² dependence of the ratios of nuclear structure functions F₂ᵃ is studied by performing QCD evolution of nuclear parton distribution functions. The log Q² slope of these ratios is very sensitive to the nuclear gluon distribution function. Taking different parametrizations, we show that the NMC data on the Q² dependence of F₂ Sn/F₂ C rule out the case where nuclear shadowing (suppression) of gluons at x 0.01 is much larger than the shadowing observed in the ratio F₂ᵃ/F₂ D. We also take into account modifications to the DGLAP evolution by including gluon fusion terms and see that the effect is small at present energies, and, in any case, a strong gluon shadowing is not favored. The region studied (x 0.01) is the most relevant for RHIC multiplicities.