Finite energy chiral sum rules in QCD
نویسندگان
چکیده
منابع مشابه
Finite energy chiral sum rules in QCD
The saturation of QCD chiral sum rules of the Weinberg-type is analyzed using ALEPH and OPAL experimental data on the difference between vector and axial-vector correlators (V-A). The sum rules exhibit poor saturation up to current energies below the tau-lepton mass. A remarkable improvement is achieved by introducing integral kernels that vanish at the upper limit of integration. The method is...
متن کاملChiral Sum Rules and Duality in QCD
The ALEPH data on the vector and axial-vector spectral functions, extracted from tau-lepton decays, is used in order to test local and global duality, as well as a set of four QCD chiral sum rules. These are the Das-Mathur-Okubo sum rule, the first and second Weinberg sum rules, and a relation for the electromagnetic pion mass difference. We find these sum rules to be poorly saturated, even whe...
متن کاملBottom-quark mass from finite energy QCD sum rules
Finite energy QCD sum rules involving both inverse and positive moment integration kernels are employed to determine the bottom quark mass. The result obtained in the MS scheme at a reference scale of 10GeV is mb(10GeV) = 3623(9)MeV. This value translates into a scale invariant mass mb(mb) = 4171(9)MeV. This result has the lowest total uncertainty of any method, and is less sensitive to a numbe...
متن کاملQCD Sum Rules and Chiral Symmetry Breaking
We investigate, in the context of QCD sum rules, the role of Goldstone bosons arising from chiral symmetry breaking, especially on the need of matching the world of hadrons to that of some effective chiral quark theory. We describe how such matching yields predictions on induced condensates which reproduce the observed value of the strong πN N coupling constant. Our result indicate that the obs...
متن کاملQCD sum rules vs . chiral perturbation theory
QCD sum rules are useful tools for studying the spectral properties of hadrons; however, assumptions underlying standard sum-rule analyses can lead to inconsistencies with known results of chiral perturbation theory. This possibility is demonstrated with QCD sum-rule extractions of the nucleon mass and σ term. In both cases, inconsistent chiral behavior leads to an uncertainty in the sum-rule p...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physics Letters B
سال: 2004
ISSN: 0370-2693
DOI: 10.1016/j.physletb.2003.11.009