Two loop gluon condensate contributions to heavy quark current correlators: Exact results and approximations
Mar, 1994
9 pages
Published in:
- Phys.Lett.B 329 (1994) 103-110
e-Print:
- hep-ph/9403274 [hep-ph]
Report number:
- OUT-4102-49,
- INP-94-1-323,
- BI-TP-94-02,
- MPI-PHT-94-2
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Abstract:
The coefficient functions of the gluon condensate , in the correlators of heavy-quark vector, axial, scalar and pseudoscalar currents, are obtained analytically, to two loops, for all values of . In the limiting cases , , and , comparisons are made with previous partial results. Approximation methods, based on these limiting cases, are critically assessed, with a view to three-loop work. High accuracy is achieved using a few moments as input. A {\em single\/} moment, combined with only the {\em leading\/} threshold and asymptotic behaviours, gives the two-loop corrections to better than 1\% in the next 10 moments. A two-loop fit to vector data yields GeV.- heavy quark
- quark: current
- correlation function
- gluon: condensation
- Feynman graph: higher-order
- renormalization
- numerical calculations
References(23)
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