Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
1998-11-06
Phys.Lett. B448 (1999) 93-98
Physics
High Energy Physics
High Energy Physics - Phenomenology
October 1998. Submitted to Phys. Lett. B. Latex file plus 7 postscript figures
Scientific paper
10.1016/S0370-2693(99)00028-3
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 when the upper limit in the dispersion integrals is as high as $3 GeV^{2}$. Since perturbative QCD, plus condensates, is expected to be valid for $|q^{2}| \geq \cal{O}$$(1 GeV^{2})$ in the whole complex energy plane, except in the vicinity of the right hand cut, we propose a modified set of sum rules with weight factors that vanish at the end of the integration range on the real axis. These sum rules are found to be precociously saturated by the data to a remarkable extent. As a byproduct, we extract for the low energy renormalization constant $\bar{L}_{10}$ the value $- 4 \bar{L}_{10}= 2.43 \times 10^{-2}$, to be compared with the standard value $- 4 \bar{L}_{10} = (2.73 \pm 0.12) \times 10^{-2}$. This in turn implies a pion polarizability $\alpha_{E} = 3.7 \times 10^{-4} fm^{3}$.
Dominguez Cesareo A.
Schilcher Karl
No associations
LandOfFree
Chiral sum rules and duality in QCD does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Chiral sum rules and duality in QCD, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chiral sum rules and duality in QCD will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-584524