Effective continuum threshold in dispersive sum rules

Autor(en)

Wolfgang Lucha, D Melikhov, Silvano Simula

Abstrakt

We study the accuracy of the bound-state parameters obtained with the method of dispersive sum rules, one of the most popular theoretical approaches in nonperturbative QCD and hadron physics. We make use of a quantum-mechanical potential model since it provides the only possibility to probe the reliability and the accuracy of this method: one obtains the bound-state parameters from sum rules and compares these results with the exact values calculated from the Schr\"odinger equation. We investigate various possibilities to fix the crucial ingredient of the method of sum rules -- the effective continuum threshold -- and propose modifications which lead to a remarkable improvement of the accuracy of the extracted ground-state parameters compared to the standard procedures adopted in the method. Although the rigorous control of systematic uncertainties in the method of sum rules remains unfeasible, the application of the proposed procedures in QCD promises a considerable increase of the actual accuracy of the extracted hadron parameters.

Organisation(en)

Teilchenphysik

Externe Organisation(en)

Lomonosov Moscow State University (MSU), Università degli Studi di Roma La Sapienza

Journal

Physical Review D

Band

79

Anzahl der Seiten

5

ISSN

1550-7998

DOI

https://doi.org/10.1103/PhysRevD.79.096011

Publikationsdatum

2009

Peer-reviewed

Ja

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/effective-continuum-threshold-in-dispersive-sum-rules(adb55483-db19-4f75-922e-95bcc7f449ca).html