TY - JOUR

T1 - Reconciling the light-cone and nonrelativistic QCD approaches to calculating e+e-→J/ψ+ηc

AU - Bodwin, Geoffrey T.

AU - Kang, Daekyoung

AU - Lee, Jungil

N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.

PY - 2006

Y1 - 2006

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=33846344285&partnerID=8YFLogxK

U2 - 10.1103/PhysRevD.74.114028

DO - 10.1103/PhysRevD.74.114028

M3 - Article

AN - SCOPUS:33846344285

SN - 1550-7998

VL - 74

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

IS - 11

M1 - 114028

ER -