Understanding nuclear effects in parton distribution functions (PDF) is an essential component needed to determine the strange and anti-strange quark contributions in the proton. In addition Nuclear Parton Distribution Functions (NPDF) are critically
important for any collider experiment with nuclei (e.g. RHIC, ALICE). Here two next-to-leading order chi^2-analyses of NPDF are presented. The first uses neutral current charged-lepton Deeply Inelastic Scattering (DIS) and Drell-Yan data for several nuclear targets and the second uses neutrino-nucleon DIS data. We compare the nuclear corrections factors (F_2^Fe/F_2^D) for the charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.
We describe in detail our calculation of the full supersymmetric (SUSY) QCD corrections to neutralino annihilation into heavy quarks and extend our numerical analysis of the resulting dark matter relic density to scenarios without scalar or gaugino m
ass unification. In these scenarios, the final state is often composed of top quarks and the annihilation proceeds through Z^0-boson or scalar top-quark exchanges. The impact of the corrections is again shown to be sizable, so that they must be taken into account systematically in global analyses of the supersymmetry parameter space.
The calculation of the cosmological relic density of the dark matter candidate within supersymmetric models is an interesting possibility to obtain additional constraints on the supersymmetric parameter space with respect to collider, electroweak pre
cision, and low-energy data. Considering future cosmological precision measurements, radiative corrections can play an important role in the analysis. We present full QCD and SUSY-QCD corrections to neutralino pair annihilation into quark-antiquark pairs and analyze their impact on the neutralino annihilation cross section and the relic density. By comparing to the relic density obtained from a pure leading order calculation, we show that the corrections strongly influence the extraction of SUSY mass parameters from cosmological data.
