PT Journal
AU Gonzalez-Alonso, M
   Pich, A
   Prades, J
TI Violation of quark-hadron duality and spectral chiral moments in QCD
SO Physical Review D
JI Phys. Rev. D
PY 2010
BP 074007
EP 10pp
VL 81
IS 7
DI 10.1103/PhysRevD.81.074007
LA English
AB We analyze the spectral moments of the V – A two-point correlation function. Using all known short-distance constraints and the most recent experimental data from tau decays, we determine the lowest spectral moments, trying to assess the uncertainties associated with the so-called violations of quark-hadron duality. We have generated a large number of acceptable spectral functions, satisfying all conditions, and have used them to extract the wanted hadronic parameters through a careful statistical analysis. We obtain accurate values for the chi PT couplings L-10 and C-87, and a realistic determination of the dimension six and eight contributions in the operator product expansion, O-6 = (-5.4(-1.6)(+3.6)) . 10(-3) GeV6 and O-8 = d(-8.9-(12.6)(7.4+)) 10(-3) GeV8, showing that the duality-violation effects have been underestimated in previous literature.
ER