Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
2011-03-02
Physics
High Energy Physics
High Energy Physics - Phenomenology
v2,9 pages, 1 figure included in pdf file, references added
Scientific paper
The recent BaBar measurements of the $\gamma\gamma^{*}\to \pi^{0}$ form factor show spectacular deviation from perturbative QCD computations for large space-like $Q^{2}$. At $34\,\rm GeV^{2}$ the data are more than 50% larger than theoretical predictions. Stimulated by these new experimental results, we revisit our previous paper on triangle loop effects related to chiral anomaly, and apply our method to the $\gamma + \gamma^* \to \pi^0$ form factor measured in the single tag mode $e^{+} + e^{-}\to e^{+} + e^{-} + \pi^{0}$ with one highly virtual photon. The resultant form factor $F(Q^{2})$ - which depends on only one parameter (the mass $m$ of up, down quark circulating in the triangle loop) behaves like $(\frac{m^{2}}{Q^{2}})\times (\ln(Q^{2}/m^{2}))^{2}$ - shows a striking agreement with BaBar data for $m \approx 132\,\rm MeV$. The rising logarithm squared form factor, surprisingly unnoticed in the literature, is in sharp contrast with the rather flat ones derived from perturbative QCD approaches.
Pham Tri Nang
Pham Xuan-Yem
No associations
LandOfFree
Chiral anomaly, triangle loop and the the $γγ^{*}\to π^{0}$ 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 Chiral anomaly, triangle loop and the the $γγ^{*}\to π^{0}$ form factor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chiral anomaly, triangle loop and the the $γγ^{*}\to π^{0}$ form factor will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-474771