A New Generation of Parton Distributions with Uncertainties from Global QCD Analysis What’s new in this Global QCD Analysis of PDF’s? • New Data, • New methods and techniques of analysis unable quantitative error treatments and reliable uncertainty studies: (J. Pumplin, D. Stump) New Results and physical applications • New generation of CTEQ PDF’s: eigenvector sets which characterize the behavior of overall χ 2 in the neighborhood of the global minimum; • Precision W/Z physics at the Tevatron/LHC • Parton Luminosities at the Tevatron, LHC, RHIC, VLHC Þ predictions on X-sections and their uncertainties for Higgs-, top-productions, high p T jets, ... etc. Outlook J. Pumplin, D.R. Stump, J. Huston, H.L. Lai, P. Nadolsky, and W.K. Tung Michigan State Univ. hep-ph/0201195 + all available correlated systematic errors (old & new)
Transcript
A New Generation of Parton Distributions with Uncertainties from Global QCD Analysis
What’s new in this Global QCD Analysis of PDF’s? • New Data,
• New methods and techniques of analysis unable quantitative error treatments and reliable uncertainty studies: (J. Pumplin, D. Stump)
New Results and physical applications • New generation of CTEQ PDF’s: eigenvector sets
which characterize the behavior of overall χ2 in the neighborhood of the global minimum;
• Precision W/Z physics at the Tevatron/LHC • Parton Luminosities at
the Tevatron, LHC, RHIC, VLHC � predictions on X-sections and their uncertainties for Higgs-, top-productions, high pT jets, ... etc.
Outlook
J. Pumplin, D.R. Stump, J. Huston, H.L. Lai, P. Nadolsky, and W.K. Tung
Michigan State Univ. hep-ph/0201195
+ all available correlated systematic errors (old & new)
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Global QCD Analysis in a Nutshell
Master Equation for QCD Parton Model
{ the Factorization Theorem
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Sources of Uncertainties and Challenges:
� Experimental errors;
� Parametrization dependence;
� Higher-order corrections; Large Logarithms;
� Power-law (higher twist) corrections.
ExperimentalInput
Parton Dist. Fn.Non-Perturbative Parametrization at Q0
Outlook This is only the very beginning of studying uncertainties
in global QCD analysis in a quantitative manner This work demonstrates that the new techniques for
global analysis developed recently are viable and practical.
The new results are very useful for the physics programs of the Tevatron, Hera, and LHC,
There is a lot of room for collaboration among theorists and experimentalists
Many other sources of uncertainties in the overall global analysis have not yet been incorporated: Theoretical uncertainties due to higher-order PQCD
corrections and resummation; Uncertainties introduced by the choice of
parametrization have been explored extensively, but not yet quantitatively formulated.
Heavy quark effects and charm production data in NC and CC experiments will be systematically analyzed � More quantitative information on strange, charm, bottom distributions.
Continued progress in this venture is of vital importance for our understanding of the parton structure of hadrons (fundamental physics of its own right), for precision SM physics studies at future colliders, and for New Physics searches.
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