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Register a new userPion Wave Function from QCD Sum Rules with Nonlocal Condensates
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Authors
Anatoly Radyushkin
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We investigate a model QCD sum rule for the pion wave function $varphi_{pi}(x)$ based on the non-diagonal correlator whose perturbative spectral density vanishes and $Phi(x,M^2)$, the theoretical side of the sum rule, consists of condensate contributions only. We study the dependence of $Phi(x,M^2)$ on the Borel parameter $M^2$ and observe that $Phi(x,M^2)$ has a humpy form, with the humps becoming more and more pronounced when $M^2$ increases. We demonstrate that this phenomenon reflects just the oscillatory nature of the higher states wave functions, while the lowest state wave function $varphi_{pi}(x)$ extracted from our QCD sum rule analysis,has no humps, is rather narrow and its shape is close to the asymptotic form $varphi_{pi}^{as}(x) = 6x(1-x)$.
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We study $bar qq$-hybrid mixing for the light vector mesons and $bar qq$-glueball mixing for the light scalar mesons in Monte-Carlo based QCD Laplace sum rules. By calculating the two-point correlation function of a vector $bar qgamma_mu q$ (scalar $bar q q$) current and a hybrid (glueball) current we are able to estimate the mass and the decay constants of the corresponding mixed physical state that couples to both currents. Our results do not support strong quark/gluonic mixing for either the $1^{--}$ or the $0^{++}$ states.
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