The strange quark mass from QCD sum rules

Abstract

The strange quark mass is calculated from QCD sum rules for the divergence of the vector as well as axial-vector current in the next-next-to-leading logarithmic approximation. The determination for the divergence of the axial-vector current is found to be unreliable due to large uncertainties in the hadronic parametrisation of the two-point function.From the sum rule for the divergence of the vector current, we obtain a value of m s ≡ m s (1 GeV) = 189 ± 32 MeV, where the error is dominated by the unknown perturbative O(α 3 s ) correction. Assuming a continued geometric growth of the perturbation series, we find m s = 178 ± 18 MeV. Using both determinations of m s , together with quark-mass ratios from chiral perturbation theory, we also give estimates of the light quark masses m u and m d .

The a0(980), a0(1450) and scalar decay constants and the isovector scalar spectrum

“…(13) reflect the range of values obtained when the K * 0 (1430) resonance parameters are varied within the errors quoted for the phase shift fit of Ref. [28], and also the difference between the values obtained using the corrected LASS fit and the fit of Ref. [28].…”

“…[28], and also the difference between the values obtained using the corrected LASS fit and the fit of Ref. [28].…”

“…ρ s (s) may, in turn, be constructed from experimental Kπ phase shifts and the value of the timelike scalar Kπ form factor, d(s), at some convenient kinematic point [28,29] since (1) unitarity relates the Kπ component of the spectral function to…”

Implications for relic neutralinos of the theoretical uncertainties in the neutralino–nucleon cross section

“…Even more spread are the values deduced with this method by various authors for the s-quark mass [36][37][38][39][40]. A combination of all these derivations: m s (1 GeV) = 170 ± 50 MeV [40] evidentiates how large is the uncertainty in the estimate of m s .…”

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

“…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].…”