QCD Sum Rule Calculation of $γγ^*\toπ^0$ Transition Form Factor

Details QCD Sum Rule Calculation of $γγ^*\toπ^0$ Transition Form Factor QCD Sum Rule Calculation of $γγ^*\toπ^0$ Transition Form Factor

1995-11-08

arxiv.org/abs/hep-ph/9511270v1

Phys.Lett. B374 (1996) 173-180

Physics

High Energy Physics

High Energy Physics - Phenomenology

13 pages LaTex, uses epsf.tex to insert figures; with 3 figures in encapsulated postscript form

Scientific paper

10.1016/0370-2693(96)00175-X

We develop a QCD sum rule analysis of the form factor $F_{\gamma^*\gamma^*\pi^0}(q^2,Q^2)$ in the region where virtuality of one of the spacelike photons is small $q^2 \ll 1 GeV^2$ while another is large: $Q^2 \gapprox 1 GeV^2$. We construct the operator product expansion suitable for this kinematic situation and obtain a QCD sum rule for $F_{\gamma^*\gamma^*\pi^0}(0,Q^2)$. Our results confirm expectation that the momentum transfer dependence of $F_{\gamma^*\gamma^*\pi^0}(0,Q^2)$ is close to interpolation between its $Q^2=0$ value fixed by the axial anomaly and $Q^{-2}$ pQCD behaviour for large $Q^2$. Our approach, in contrast to pQCD, does not require additional assumptions about the shape of the pion distribution amplitude $\varphi_{\pi}(x)$. The absolute value of the $1/Q^2$ term obtained in this paper favours $\varphi_{\pi}(x)$ close to the asymptotic form $\varphi_{\pi}^{as} (x)=6 f_{\pi} x (1-x)$.

Affiliated with

Also associated with

No associations

Rating

QCD Sum Rule Calculation of $γγ^*\toπ^0$ Transition Form Factor does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with QCD Sum Rule Calculation of $γγ^*\toπ^0$ Transition Form Factor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and QCD Sum Rule Calculation of $γγ^*\toπ^0$ Transition Form Factor will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-67707