TABLE II: Expected and observed 95% C.L. limits on various new physics models. Model (parameter) Expected (TeV) Observed (TeV) Quark Compositeness (Λ) η = +1 2.76 2.84 η = − 1 2.75 2.82 TeV − 1 ED ( M$_{C}$ ) 1.60 1.55 ADD LED ( M$_{S}$ ) GRW 1.47 1.59 HLZ n = 3 1.75 1.89 HLZ n = 4 1.47 1.59 HLZ n = 5 1.33 1.43 HLZ n = 6 1.24 1.34 HLZ n = 7 1.17 1.26 [TeV] JJ M 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 [pb/(TeV)] max d | y | JJ /dM 2  d -3 10$^{-2}$ 10$^{-1}$ 10 1 10 2 10$^{3}$ 10$^{4}$ 10$^{5}$ 10$^{6}$ 10$^{7}$ 10$^{8}$ 10$^{9}$ 10 10 10$^{11}$ 10$^{12}$ 10  < 2.4 (x100000) max 2.0 < |y|  < 2.0 (x10000) max 1.6 < |y|  < 1.6 (x1000) max 1.2 < |y|  < 1.2 (x100) max 0.8 < |y|  < 0.8 (x10) max 0.4 < |y|  < 0.4 max |y| MSTW2008 NLO + non-perturbative corrections )/2 T,2  + p T,1  = (p DØ Preliminary  = 0.7 cone R -1 L = 0.7 fb  = 1.96 TeV s Data/Theory  0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 |y| < 0.4 DØ Preliminary -1 L = 0.7 fb  = 0.7 cone R 0 0.2 0.4 0.6 0.8 1 1.2 1.4 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Data Systematic Uncertainty | < 1.6 max 1.2 < |y  < 0.8 max 0.4 < |y| 0.2 0.4 0.6 0.8 1 1.2 1.4 MSTW2008 Scale Uncertainty PDF Uncertainty (MSTW2008)  < 2.0 max 1.6 < |y|  < 1.2 max 0.8 < |y| )/2 T,2  + p T,1  = (p T  = p F  =  R  [TeV] JJ M 0.2 0.4 0.6 0.8 1 1.2 1.4 CTEQ6.6/MSTW(2008) | < 2.4 max 2.0 < |y FIG. 11: (left) DØ’s dijet mass measurement for six rapidity bins [72] compared to NLO using MSTW2008 PDFs. (right) Ratio of data/theory. The experimental systematic uncertainties are very small. The dashed line shows the effect of using the CTEQ6.6M PDFs. 34