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Extraction of ground-state decay constant from dispersive sum rules: QCD vs potential models
- Source :
-
Physics Letters B . Apr2010, Vol. 687 Issue 1, p48-52. 5p. - Publication Year :
- 2010
-
Abstract
- Abstract: We compare the extraction of the ground-state decay constant from the two-point correlator in QCD and in potential models and show that the results obtained at each step of the extraction procedure follow a very similar pattern. We prove that allowing for a Borel-parameter-dependent effective continuum threshold yields two essential improvements compared to employing a Borel-parameter-independent quantity: (i) It reduces considerably the (unphysical) dependence of the extracted bound-state mass and the decay constant on the Borel parameter. (ii) In a potential model, where the actual value of the decay constant is known from the Schrödinger equation, a Borel-parameter-dependent threshold leads to an improvement of the accuracy of the extraction procedure. Our findings suggest that in QCD a Borel-parameter-dependent threshold leads to a more reliable and accurate determination of bound-state characteristics by the method of sum rules. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 03702693
- Volume :
- 687
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Physics Letters B
- Publication Type :
- Academic Journal
- Accession number :
- 48724549
- Full Text :
- https://doi.org/10.1016/j.physletb.2010.02.080