Nexttoleadingorder QCD correction to inclusive J/{psi}({Upsilon}) production in Z{sup 0} decay
Abstract
In this paper, we study the J/{psi}({Upsilon}) production in Z boson decay in a colorsinglet model (CSM). We calculate the nexttoleadingorder (NLO) QCD correction to Z{yields}quarkonium+QQ, the dominant contribution in the CSM, with the vector and axialvector parts in the ZQQ vertex being treated separately. The results show that the vector and axialvector parts have the same K factor (the ratio of the NLO result to the leadingorder result) 1.13 with the renormalization scale {mu}=2m{sub c} and m{sub c}=1.5 GeV, and the K factor falls to 0.918 when applying the Brodsky, Lepage, and Mackenzie (BLM) renormalization scale scheme with obtained {mu}{sub BLM}=2.28 GeV and m{sub c}=1.5 GeV. By including the contributions from the nextdominant ones, the photon and gluon fragmentation processes, the branching ratio for Z{yields}J/{psi}{sub prompt}+X is (7.310.0)x10{sup 5} with the uncertainty consideration for the renormalization scale and charm quark mass. The results are about onehalf of the central value of the experimental measurement 2.1x10{sup 4}. Furthermore, the J/{psi} energy distribution in our calculation cannot describe the experimental data. Therefore, even at QCD NLO, the contribution to Z{yields}J/{psi}{sub prompt}+X from the CSM cannot fully account for the experimental measurement. And there should be contributions from other mechanisms, such asmore »
 Authors:

 Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918(4), Beijing, 100049, China, and Theoretical Physics Center for Science Facilities, CAS, Beijing, 100049 (China)
 Publication Date:
 OSTI Identifier:
 21432959
 Resource Type:
 Journal Article
 Journal Name:
 Physical Review. D, Particles Fields
 Additional Journal Information:
 Journal Volume: 82; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevD.82.054006; (c) 2010 American Institute of Physics; Journal ID: ISSN 05562821
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BRANCHING RATIO; COLOR MODEL; COMPUTERIZED SIMULATION; CORRECTIONS; ENERGY SPECTRA; FRAGMENTATION; GEV RANGE 0110; GLUONS; J PSI3097 MESONS; MASS; PARTICLE DECAY; PARTICLE PRODUCTION; PHOTONS; QUANTUM CHROMODYNAMICS; QUARKONIUM; QUARKS; RENORMALIZATION; Z NEUTRAL BOSONS; BOSONS; CHARMONIUM; COMPOSITE MODELS; DECAY; DIMENSIONLESS NUMBERS; ELEMENTARY PARTICLES; ENERGY RANGE; FERMIONS; FIELD THEORIES; GEV RANGE; HADRONS; INTERMEDIATE BOSONS; INTERMEDIATE VECTOR BOSONS; MASSLESS PARTICLES; MATHEMATICAL MODELS; MESONS; PARTICLE MODELS; QUANTUM FIELD THEORY; QUARK MODEL; SIMULATION; SPECTRA; VECTOR MESONS
Citation Formats
Li, Rong, and Wang, JianXiong. Nexttoleadingorder QCD correction to inclusive J/{psi}({Upsilon}) production in Z{sup 0} decay. United States: N. p., 2010.
Web. doi:10.1103/PHYSREVD.82.054006.
Li, Rong, & Wang, JianXiong. Nexttoleadingorder QCD correction to inclusive J/{psi}({Upsilon}) production in Z{sup 0} decay. United States. https://doi.org/10.1103/PHYSREVD.82.054006
Li, Rong, and Wang, JianXiong. Wed .
"Nexttoleadingorder QCD correction to inclusive J/{psi}({Upsilon}) production in Z{sup 0} decay". United States. https://doi.org/10.1103/PHYSREVD.82.054006.
@article{osti_21432959,
title = {Nexttoleadingorder QCD correction to inclusive J/{psi}({Upsilon}) production in Z{sup 0} decay},
author = {Li, Rong and Wang, JianXiong},
abstractNote = {In this paper, we study the J/{psi}({Upsilon}) production in Z boson decay in a colorsinglet model (CSM). We calculate the nexttoleadingorder (NLO) QCD correction to Z{yields}quarkonium+QQ, the dominant contribution in the CSM, with the vector and axialvector parts in the ZQQ vertex being treated separately. The results show that the vector and axialvector parts have the same K factor (the ratio of the NLO result to the leadingorder result) 1.13 with the renormalization scale {mu}=2m{sub c} and m{sub c}=1.5 GeV, and the K factor falls to 0.918 when applying the Brodsky, Lepage, and Mackenzie (BLM) renormalization scale scheme with obtained {mu}{sub BLM}=2.28 GeV and m{sub c}=1.5 GeV. By including the contributions from the nextdominant ones, the photon and gluon fragmentation processes, the branching ratio for Z{yields}J/{psi}{sub prompt}+X is (7.310.0)x10{sup 5} with the uncertainty consideration for the renormalization scale and charm quark mass. The results are about onehalf of the central value of the experimental measurement 2.1x10{sup 4}. Furthermore, the J/{psi} energy distribution in our calculation cannot describe the experimental data. Therefore, even at QCD NLO, the contribution to Z{yields}J/{psi}{sub prompt}+X from the CSM cannot fully account for the experimental measurement. And there should be contributions from other mechanisms, such as the coloroctet (COM) contributions. We define R{sub cc}=({Gamma}(Z{yields}J/{psi}ccX)/{Gamma}(Z{yields}J/{psi}X)) and obtain R{sub cc}=0.84 for only the CSM contribution and R{sub cc}=0.49 for COM and CSM contributions together. Then the R{sub cc} measurement could be used to clarify the COM contributions.},
doi = {10.1103/PHYSREVD.82.054006},
url = {https://www.osti.gov/biblio/21432959},
journal = {Physical Review. D, Particles Fields},
issn = {05562821},
number = 5,
volume = 82,
place = {United States},
year = {2010},
month = {9}
}