1. Sept 2003PHYSTAT61 Uncertainties of Parton Distributions (II) Results

2. Sept 2003PHYSTAT62 Estimate the uncertainty on the predicted cross section for pp bar  W+X at the Tevatron collider. global  2 local  2 ’s

3. Sept 2003PHYSTAT63 Each experiment defines a “prediction” and a “range”. This figure shows the  2 = 1 ranges.

4. Sept 2003PHYSTAT64 This figure shows broader ranges for each experiment based on the “90% confidence level” (cumulative distribution function of the rescaled  2 ).

5. Sept 2003PHYSTAT65 The final result is an uncertainty range for the prediction of  W. Survey of  w  B l  predictions (by R. Thorne) … PDF setenergy  w  B l  nb  PDF uncert AlekhinTevatron2.73  0.05 MRST2002Tevatron2.59  0.03 CTEQ6Tevatron2.54  0.10 AlekhinLHC215.  6. MRST2002LHC204.  4. CTEQ6LHC205.  8.

6. Sept 2003PHYSTAT66 How well can we determine the value of  S ( M Z ) from Global Analysis? For each value of  S, find the best global fit. Then look at the  2 value for each experiment as a function of  S.

7. Sept 2003PHYSTAT67 Each experiment defines a “prediction” and a “range”. This figure shows the  2 = 1 ranges. Particle data group (shaded strip) is 0.117  0.002. The fluctuations are larger than expected for normal statistics. The vertical lines have  2 global =100,  s (MZ)=0.1165  0.0065

8. Sept 2003PHYSTAT68 Uncertainties of the PDF’s themselves (only interesting to the model builders) Gluon and U quark at Q 2 = 10 GeV 2.

9. Sept 2003PHYSTAT69 Comparing “alternate sets” Gluon at Q 2 = 10 GeV 2 U quark at Q 2 = 10 GeV 2 red – CTEQ6.1blue – Fermi2002 (H1, BCDMS, E665)

10. Sept 2003PHYSTAT70 CTEQ error band with MRST2002 superimposed Q 2 = 10 GeV 2

11. Sept 2003PHYSTAT71 Uncertainties of LHC parton-parton luminosities Provides simple estimates of PDF uncertainties at the LHC.