QCD and resonance physics. theoretical foundations

Shifman, M.; Vainshtein, A.I.; Захаров, В. И.

doi:10.1016/0550-3213(79)90022-1

Cited by 4,898 publications

(3,827 citation statements)

References 37 publications

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“…Of particular interest is their difference Π(t) ≡ Π S (t) − Π P (t), which is identically zero in QCD perturbation theory. When t → ∞, this correlator vanishes as 1/t 2 , with a coefficient proportional to α s qΓqqΓq [28,29]. The low-momentum expansion of Π(t) is determined by χPT to have the form [4,7] Π(t) = B 2 0 [4,7].…”

Section: The Large-n C Limitmentioning

confidence: 99%

Towards a determination of the chiral couplings at NLO in 1/N_C: L₈^r(μ) and C₃₈^r(μ)

Rosell

Pich

Sanz-Cillero

2007

J. High Energy Phys.

126

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We present a dispersive method which allows to investigate the low-energy couplings of chiral perturbation theory at the next-to-leading order (NLO) in the 1/N C expansion, keeping full control of their renormalization scale dependence. Using the resonance chiral theory Lagrangian, we perform a NLO calculation of the scalar and pseudoscalar twopoint functions, within the single-resonance approximation. Imposing the correct QCD short-distance constraints, one determines their difference Π(t) ≡ Π S (t) − Π P (t) in terms of the pion decay constant and resonance masses. Its low momentum expansion fixes then the low-energy chiral couplings L 8 and C 38 . At µ 0 = 0.77 GeV, we obtain L r 8 (µ 0 ) SU (3) = (0.6 ± 0.4) · 10 −3 and C r 38 (µ 0 ) SU (3) = (2 ± 6) · 10 −6 .

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Section: The Large-n C Limitmentioning

confidence: 99%

Towards a determination of the chiral couplings at NLO in 1/N_C: L₈^r(μ) and C₃₈^r(μ)

Rosell

Pich

Sanz-Cillero

2007

J. High Energy Phys.

126

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“…Among those theoretical methods in dealing with the non-perturbative effects, QCD Sum Rules innovated by Shifman et al [25] turns out to be a remarkably successful and powerful technique for the computation of hadronic properties. By virtue of QCD Sum Rules, hybrids with various quantum numbers and the flavors have been investigated.…”

Section: Introductionmentioning

confidence: 99%

Determining 1⁻⁻heavy hybrid masses via QCD sum rules

Qiao¹,

Tang²,

Hao³

et al. 2011

J. Phys. G: Nucl. Part. Phys.

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The masses of 1 −− charmonium and bottomonium hybrids are evaluated in terms of QCD sum rules. We find that the ground state hybrid in charm sector lies in m Hc = 4.12 ∼ 4.79 GeV, while in bottom sector the hybrid may situated in m H b = 10.24 ∼ 11.15 GeV. Since the numerical result on charmonium hybrid mass is not compatible with the charmonium spectra, including structures newly observed in experiment, we tempt to conclude that such a hybrid does not purely exist, but rather as an admixture with other states, like glueball and regular quarkonium, in experimental observation. However, our result on bottomonium hybrid coincide with the "exotic structure" recently observed at BELLE.

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“…More than twenty five years ago, Shifman, Vainshtein and Zakharov [1] proposed to use the Operator Product Expansion (OPE) in hadronic current-current correlators to extend asymptotic predictions of QCD to low energies. In this approach there appear universal vacuum expectation values of quark and gluon fields, the so-called vacuum condensates, which have to be extracted from experiment.…”

Section: Introductionmentioning

confidence: 99%

Chiral condensates from tau decay: a critical reappraisal

Bordes

Domínguez

Peñarrocha

et al. 2006

J. High Energy Phys.

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The saturation of QCD chiral sum rules is reanalyzed in view of the new and complete analysis of the ALEPH experimental data on the difference between vector and axial-vector correlators (V-A). Ordinary finite energy sum rules (FESR) exhibit poor saturation up to energies below the tau-lepton mass. A remarkable improvement is achieved by introducing pinched, as well as minimizing polynomial integral kernels. Both methods are used to determine the dimension d = 6 and d = 8 vacuum condensates in the Operator Product Expansion, with the results: O 6 (2.6 GeV 2 ) = −(0.00226 ± 0.00055) GeV 6 , and O 8 (2.6 GeV 2 ) = −(0.0054 ± 0.0033) GeV 8 from pinched FESR, and compatible values from the minimizing polynomial FESR. Some higher dimensional condensates are also determined, although we argue against extending the analysis beyond dimension d = 8. The value of the finite remainder of the (V-A) correlator at zero momentum is also redetermined:Π(0) = −4L 10 = 0.02579±0.00023. The stability and precision of the predictions are significantly improved compared to earlier calculations using the old ALEPH data. Finally, the role and limits of applicability of the Operator Product Expansion in this channel are clarified.

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QCD and resonance physics. theoretical foundations

Cited by 4,898 publications

References 37 publications

Towards a determination of the chiral couplings at NLO in 1/N_C: L₈^r(μ) and C₃₈^r(μ)

Towards a determination of the chiral couplings at NLO in 1/N_C: L₈^r(μ) and C₃₈^r(μ)

Determining 1⁻⁻heavy hybrid masses via QCD sum rules

Chiral condensates from tau decay: a critical reappraisal

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QCD and resonance physics. theoretical foundations

Cited by 4,898 publications

References 37 publications

Towards a determination of the chiral couplings at NLO in 1/NC: L8r(μ) and C38r(μ)

Towards a determination of the chiral couplings at NLO in 1/NC: L8r(μ) and C38r(μ)

Determining 1−−heavy hybrid masses via QCD sum rules

Chiral condensates from tau decay: a critical reappraisal

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Towards a determination of the chiral couplings at NLO in 1/N_C: L₈^r(μ) and C₃₈^r(μ)

Towards a determination of the chiral couplings at NLO in 1/N_C: L₈^r(μ) and C₃₈^r(μ)

Determining 1⁻⁻heavy hybrid masses via QCD sum rules