Gluon Condensates and precise from QCD-Moments and their ratios to Order and < G >
May, 201111 pages
Published in:
- Phys.Lett.B 706 (2012) 412-422
- Published: Jan 5, 2012
e-Print:
- 1105.2922 [hep-ph]
PDG: -QUARK MASS
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Abstract: (Elsevier)
We reconsider the extraction of the gluon condensates 〈αsG2〉 , 〈g3fabcG3〉 and the MS¯ running quark masses m¯c,b from different Mn(Q2) moments and their ratios by including PT corrections to order αs3 , NPT terms up to 〈G4〉 and using stability criteria of the results versus the degree n (number of Q2 -derivative). We explicitly show that the spectral part of the lowest moment M1(0) depends strongly (as expected) on its high-energy (continuum) contribution, which is minimized for Mn⩾3−4(0) . Using higher moments and the correlations of 〈αsG2〉 with 〈g3fabcG3〉 and 〈G4〉 , we obtain 〈αsG2〉=(7.0±1.3)×10−2 GeV4 and 〈g3fabcG3〉=(8.8±5.5) GeV2×〈αsG2〉 , while our analysis favours a modified precise factorisation for 〈G4〉 . Using the previous results, we re-determine m¯c(m¯c) and find that the commonly used M1(0) lowest moment tends to overestimate its value compared to the ones from higher moments where stable values of m¯c(m¯c) versus the variations of n and the continuum models are reached. These features can indicate that the quoted errors of m¯c,b from M1(0) may have been underestimated. Our best results from different high- n moments and their ratios are: m¯c(m¯c)=1261(16) MeV and m¯b(m¯b)=4171(14) MeV , in excellent agreement with results obtained in Narison (2010) [1] using some judicious choices of ratios of moments.Note:
- 11 pages, 9 figures, 5 tables. Improved version to appear in Phys. Lett. B including a reevaluation of the different sources of the errors
- QCD spectral sum rules
- Gluon condensates
- Heavy quark masses
- gluon: condensation
- charm: mass
- bottom: mass
- stability
- moment: higher-order
- factorization
- quantum chromodynamics
References(76)
Figures(18)