On the heavy quark mass expansion for the operator Qbar gamma_5 Q and the charm content of eta, eta'

Abstract

Recently in the context of studies of the intrinsic charm content of the nucleon and of the eta' meson two groups have arrived at different results for the 1/m^3 term of the heavy quark expansion for operator $\bar{Q}{\gamma }_{5}Q$ differing by the factor of six. We show that the form of both results violates certain general conditions. Using the expression for the axial anomaly with the finite Pauli-Villars regularization we obtain a new expression for 1/m^3 term of the heavy quark expansion for $\bar{Q}{\gamma }_{5}Q$. With this new result we obtain an estimate for the constant f_{η'}^{(c)}=-2 MeV.

arXiv comment4 pages

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Cited by in corpus (12)

• Quark structure of pseudoscalar mesons
• Charmless Hadronic Two-body Decays of B_u and B_d Mesons
• Heavy quark mass expansion and intrinsic charm in light hadrons
• The intrinsic charm contribution to the proton spin
• Spin-dependent twist-4 matrix elements from the instanton vacuum: Flavor-singlet and nonsinglet
• A gluonic mechanism for B --> D eta'
• The Coupling of eta Mesons to Quarks and Baryons from D_s^* -> D_s pi^0 Decay
• Power corrections to the space-like transition form factor F_{η^{\prime}g^{*}g^{*}}(Q^2,ω)
• Semi-inclusive B Decays and Direct CP Violation in QCD Factorization
• Heavy quark mass expansion of vector and tensor currents and intrinsic charm in nucleon form factors
• Soft end-point and mass corrections to the eta' g*g* vertex function
• Nucleon matrix element of Weinberg's CP-odd gluon operator from the instanton vacuum