scholarly journals Towards a Solution of the Charmonium Production Controversy:k⊥Factorization versus Color-Octet Mechanism

2001 ◽  
Vol 86 (8) ◽  
pp. 1446-1449 ◽  
Author(s):  
Ph. Hägler ◽  
R. Kirschner ◽  
A. Schäfer ◽  
L. Szymanowski ◽  
O. V. Teryaev
Keyword(s):  
Charmonium Production ◽  
Color Octet ◽  
Color Octet Mechanism ◽  
Versus Color

scholarly journals Quarkonium Production at Z0 and in ϒ(1S) Decay

1997 ◽  
Vol 12 (22) ◽  
pp. 3931-3940
Author(s):  
Kingman Cheung ◽  
Wai-Yee Keung ◽  
Tzu Chiang Yuan
Keyword(s):  
Color Singlet ◽  
Fixed Target ◽  
Production Rates ◽  
Fixed Target Experiments ◽  
Color Octet ◽  
Quarkonium Production ◽  
Color Octet Mechanism

The conventional color-singlet model was challenged by the recent data on quarkonium production. Discrepancies in production rates were observed at the Tevatron, at LEP, and in fixed-target experiments. The newly advocated color-octet mechanism provides a plausible solution to the anomalous quarkonium production observed at the Tevatron. The color-octet mechanism should also affect other quarkonium production channels. In this paper we will summarize the studies of quarkonium production in Z0 and ϒ decays.

scholarly journals Color-octet mechanism andJ/ψpolarization at CERN LEP

1997 ◽  
Vol 55 (11) ◽  
pp. 6839-6843 ◽  
Author(s):  
Seungwon Baek ◽  
P. Ko ◽  
Jungil Lee ◽  
H. S. Song
Keyword(s):  
Color Octet ◽  
Color Octet Mechanism

scholarly journals POWER SCALING RULES FOR CHARMONIA PRODUCTION AND HQEFT

2001 ◽  
Vol 16 (25) ◽  
pp. 4189-4206 ◽  
Author(s):  
MIGUEL-ANGEL SANCHIS-LOZANO
Keyword(s):  
Heavy Quark ◽  
Effective Field ◽  
Tree Level ◽  
Power Scaling ◽  
Color Octet ◽  
Heavy Quark Mass ◽  
Effective Lagrangian ◽  
Pair Annihilation ◽  
Color Octet Mechanism ◽  
Local Operators

We discuss the power scaling rules along the lines of a complete heavy quark effective field theory (HQEFT) for the description of heavy quarkonium production through a color-octet mechanism. To this end, we firstly derive a tree-level heavy quark effective Lagrangian keeping both particle–antiparticle mixed sectors allowing for heavy quark–antiquark pair annihilation and creation, but describing only low-energy modes around the heavy quark mass. Then we show the consistency of using HQEFT fields in constructing four-fermion local operators à la NRQCD, to be identified with standard color-octet matrix elements. We analyze some numerical values extracted from charmonia production by different authors and their hierarchy in the light of HQEFT.

scholarly journals Color-octet mechanism in the inclusive D-wave charmonium productions in B decays

1997 ◽  
Vol 395 (1-2) ◽  
pp. 107-112 ◽  
Author(s):  
Pyungwon Ko ◽  
Jungil Lee ◽  
H.S. Song
Keyword(s):  
B Decays ◽  
Color Octet ◽  
Color Octet Mechanism ◽  
D Wave

scholarly journals υ decay into charmonium and the color octet mechanism

1994 ◽  
Vol 320 (1-2) ◽  
pp. 145-151 ◽  
Author(s):  
Howard D. Trottier
Keyword(s):  
Color Octet ◽  
Color Octet Mechanism

scholarly journals Color-octet mechanism inγ+p→Jψ+X

1996 ◽  
Vol 54 (7) ◽  
pp. 4312-4325 ◽  
Author(s):  
Pyungwon Ko ◽  
Jungil Lee ◽  
H. S. Song
Keyword(s):  
Color Octet ◽  
Color Octet Mechanism

Color-octet mechanism in low-pT Ψ′-productions

1998 ◽  
Vol 629 (1-2) ◽  
pp. 282-285
Author(s):  
T. Morii ◽  
D. Roy ◽  
K. Sudoh ◽  
Z.-X. Sun ◽  
S. Tanaka ◽  
...  
Keyword(s):  
Color Octet ◽  
Color Octet Mechanism

scholarly journals Charmonium Production in Fermilab E789

1997 ◽  
Vol 12 (22) ◽  
pp. 3827-3836 ◽  
Author(s):  
Daniel M. Kaplan
Keyword(s):  
Perturbative Qcd ◽  
Cross Sections ◽  
Differential Cross ◽  
Production Cross ◽  
Differential Cross Sections ◽  
Color Singlet ◽  
Charmonium Production ◽  
Detailed Understanding ◽  
Color Octet ◽  
Beauty Production

Using a sample of > 105 J/ψ → μ+ μ- decays, Fermilab experiment 789 has studied production of J/ψ and ψ′ in 800 GeV proton-nucleon collisions. Differential cross sections and nuclear dependences have been measured for charmonium as well as for charm and beauty production. While charm and beauty production are consistent with perturbative QCD calculations, charmonium cross sections exceed the predictions of the color-singlet model by large factors, suggesting that additional mechanisms (such as color-octet production) may play important roles. Nuclear dependences of production cross sections may offer a new tool for the detailed understanding of charmonium production.

scholarly journals AssociatedJ/ψ+γphotoproduction as a probe of the color-octet mechanism

1997 ◽  
Vol 55 (11) ◽  
pp. 7126-7133 ◽  
Author(s):  
Matteo Cacciari ◽  
Mario Greco ◽  
Michael Krämer
Keyword(s):  
Color Octet ◽  
Color Octet Mechanism
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