P 1 charmonium state decay into p p̄ in QCD models including constituent quark mass corrections
نویسنده
چکیده
Stimulated by the experimental observation, made by the E760 Collaboration at Fermilab, of the P1 state of charmonium resonantly formed in p p̄ annihilation, we perform a calculation of the decay width for the P1 → p p̄ process. To this end, we employ a phenomenological model which adds constituent quark mass corrections to the usual massless QCD models for exclusive processes. For massless models, in fact, the process under consideration is forbidden by the so-called helicity selection rules, while it is allowed in our extended model. We find Γ(P1 → p p̄) to be in the range 1 − 10 eV. We also compare our results with previous, indirect estimates, based on QCD multipole expansion models. PACS numbers: 13.25.Gv, 12.38.Bx, 14.40.Gx Typeset using REVTEX
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