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Subtracting IR ambiguity from QCD potential. Y. Sumino (Tohoku Univ.). Plan of Talk. OPE of in Potential-NRQCD UV contribution “ Coulomb+linear ” pot. by log resummation 3. Interpretation Relation to integration-by-regions technique 4. Conclusions.
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Subtracting IR ambiguity from QCD potential Y. Sumino (Tohoku Univ.)
Plan of Talk • OPE of in Potential-NRQCD • UV contribution • “Coulomb+linear” pot. by log resummation • 3. Interpretation • Relation to integration-by-regions technique • 4. Conclusions
Consider short-distance expansion of at IR renormalons in pert. QCD prediction integrated out Brambilla, Pineda, Soto, Vairo OPE of QCD potential in Potential-NRQCD multipole expansion in Uncetainty in replaced by non-local gluon condensate (non-pert. matrix element). IR gluon ) singlet octet singlet UV contr. IR contr.
Consider short-distance expansion of at IR renormalons in pert. QCD prediction integrated out Brambilla, Pineda, Soto, Vairo OPE of QCD potential in Potential-NRQCD multipole expansion in Uncetainty in replaced by non-local gluon condensate (non-pert. matrix element). IR gluon ) singlet octet singlet UV contr. IR contr.
UV contribution : LL resum. We obtain expansion in as follows.
UV contribution : LL resum. We obtain expansion in as follows.
UV contribution • Along , justified to expand in , since : and can be computed analytically.
UV contribution • Along , justified to expand in , since : and can be computed analytically: independent ! Cauchy thm
UV contribution independent
UV contribution A short-distance expansion with correct RG log in Coulomb term (as ) independent
genuinely UV including subleading logs vs. lattice comp.
Interpretation of Contributions from IR region subtracted as contour integrals surrounding pole (singularity) at . Can be regarded as generalization of ``integration-by-regions’’ technique.
“Integration-by-regions” method Simplified example:
“Integration-by-regions” method Simplified example:
“Integration-by-regions” method Simplified example:
“Integration-by-regions” method Simplified example: Contribution of each scale given by contour integral around singularity
Conclusions • OPE of • Log resummation in Short-distance expansion combines with non-pert. matrix element at Separate genuinely UV contr. hep-ph/0505034 • Do not add a linear pot. at . • Subtract IR contr. to include non-pert. matrix element. Generalization to other observables?