 [GeV/c] JET T p 0 100 200 300 400 500 600 700  [nb/(GeV/c)] JET T  dp JET  / dy 2 d -14 10$^{-11}$ 10 -8 10$^{-5}$ 10$^{-2}$ 10 10 4 10$^{7}$ 10 10 D=0.7 T K  ) -1 CDF data ( L = 1.0 fb Systematic uncertainties NLO: JETRAD CTEQ6.1M corrected to hadron level 0  / 2 =  JET T  = max p F  =  R PDF uncertainties ) -6  10 |<2.1 ( JET 1.6<|y ) -3  10 |<1.6 ( JET 1.1<|y |<1.1 JET 0.7<|y ) 3  10 |<0.7 ( JET 0.1<|y ) 6  10 |<0.1 ( JET |y 1 2 3 |<0.1 JET |y |<0.7 JET 0.1<|y Ratio to CTEQ6.1M 1 2 3 |<1.1 JET 0.7<|y  [GeV/c] JET T p 200 400 600 |<1.6 JET 1.1<|y  [GeV/c] JET T p 0 200 400 600 1 2 3 |<2.1 JET 1.6<|y D=0.7  T K  ) -1 CDF data ( L = 1.0 fb Systematic uncertainties PDF uncertainties$_{JET}$ T  = max p 0  = 2 x  MRST2004 FIG. 5: (top) CDF’s inclusive jet differential cross sections measured using the k$_{T}$ clustering algorithm in five rapidity regions. The data has been corrected to the particle jets and is compared to next to leading order (NLO) QCD predictions [47]. The NLO QCD predictions are calculated with the CTEQ6.1M parton distribution functions. (bottom) Ratios of the measured cross sections over the NLO QCD predictions. The perturbative NLO QCD calculations are in good agreement with the data. (lepton pairs and W/Z bosons) production in pp [53] and p ¯ p collisions [54], jet data from Tevatron and data from many other experiments, especially low energy, are used to extract the PDFs using a global fit. These experiments are sensitive to different f$_{i}$ . For example, e $^{±}$p experiments are sensitive to the sum of the q and ¯ q distributions weighted by e 2 q (¯ q ) and can not distinguish between quark and anti-quark distributions. Neutrino and anti-neutrino data are used to differentiate between q and ¯ q . The Tevatron jet data play a significant 23