Is the Belle result for the cross section σ (e+e- → J / ψ +ηc) a real difficulty for QCD?
Abstract
It is argued that difficulties in reconciling the values of the cross-section σ (e+e- → J / ψ +ηc) measured at Belle and calculated within non-relativistic QCD (NRQCD) are caused not by some misinterpretation of the data or other exotic explanations, but by poor applicability of NRQCD to such processes.
We use general theory of hard exclusive processes in QCD together with more realistic models of charmonium wave functions, and show that the Belle result can be naturally explained.- Publication:
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Physics Letters B
- Pub Date:
- April 2005
- DOI:
- 10.1016/j.physletb.2005.03.021
- arXiv:
- arXiv:hep-ph/0412335
- Bibcode:
- 2005PhLB..612..215B
- Keywords:
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- High Energy Physics - Phenomenology;
- High Energy Physics - Experiment
- E-Print:
- 13 pages, 2 figures, LaTeX, v2: the text is significantly improved, the erroneous fig.2 is replaced, results changed only slightly
