Reconciling the light-cone and nonrelativistic QCD approaches to calculating e+e-→J/ψ+ηc

Geoffrey T. Bodwin, Daekyoung Kang, Jungil Lee

Research output: Contribution to journalArticlepeer-review

79 Citations (Scopus)


It has been suggested in Ref. that the disagreement between theoretical calculations and experimental observations for the rate for the process e+e-→J/ψ+ηc at the B factories might be resolved by using the light-cone method to take into account the relative momentum of the heavy-quark and antiquark in the quarkonia. The light-cone result for the production cross section in Ref. is almost an order-of-magnitude larger than existing NRQCD factorization results. We investigate this apparent theoretical discrepancy. We compute light-cone distribution functions by making use of quarkonium wave functions from the Cornell potential model. Our light-cone distribution functions are similar in shape to those of Ref. and yield a similar cross section. However, when we subtract parts of the light-cone distribution functions that correspond to corrections of relative-order αs in the NRQCD approach, we find that the cross section decreases by about a factor of three. When we set certain renormalization factors Zi in the light-cone calculation equal to unity, we find a further reduction in the cross section of about a factor of two. The resulting light-cone cross section is similar in magnitude to the NRQCD factorization cross sections and shows only a modest enhancement over the light-cone cross section in which the relative momentum of the heavy-quark and antiquark is neglected.

Original languageEnglish
Article number114028
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number11
Publication statusPublished - 2006

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


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