scholarly journals ηcProduction at the LHC Challenges Nonrelativistic QCD Factorization

2015 ◽  
Vol 114 (9) ◽  
Author(s):  
Mathias Butenschoen ◽  
Zhi-Guo He ◽  
Bernd A. Kniehl
Keyword(s):  
Qcd Factorization ◽  
Nonrelativistic Qcd

scholarly journals Covariant calculation of a two-loop test of nonrelativistic QCD factorization

2020 ◽  
Vol 101 (9) ◽  
Author(s):  
Geoffrey T. Bodwin ◽  
Hee Sok Chung ◽  
June-Haak Ee ◽  
U-Rae Kim ◽  
Jungil Lee
Keyword(s):  
Qcd Factorization ◽  
Nonrelativistic Qcd ◽  
Covariant Calculation

scholarly journals Next-to-leading-order study of J/ψ angular distributions in e+e− → J/ψ + ηc, χcJ at $$ \sqrt{s} $$ ≈ 10.6 GeV

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Zhan Sun
Keyword(s):  
Cross Sections ◽  
Charm Quark ◽  
Experimental Result ◽  
Angular Distributions ◽  
Matrix Elements ◽  
Leading Order ◽  
Charm Quark Mass ◽  
Qcd Factorization ◽  
Nonrelativistic Qcd ◽  
Good Agreement

Abstract In this paper, we present a detailed next-to-leading-order (NLO) study of J/ψ angular distributions in e+e−→ J/ψ + ηc, χcJ (J = 0, 1, 2) within the nonrelativistic QCD factorization (NRQCD). The numerical NLO expressions for total and differential cross sections, i.e., $$ \frac{d\sigma}{d\cos \theta } $$ dσ d cos θ = A + B cos2θ, are both derived. With the inclusion of the newly-calculated QCD corrections to A and B, the αθ (= B/A) parameters in J/ψ + χc0 and J/ψ + χc1 are moderately enhanced, while the magnitude of αθJ/ψ+χc2 is significantly reduced; regarding the production of J/ψ + ηc, the αθ value remains unchanged. By comparing with experiment, we find the predicted αθJ/ψ+ηc is in good agreement with the Belle measurement; however, αθJ/ψ+χc0 is still totally incompatible with the experimental result, and this discrepancy seems to hardly be cured by proper choices of the charm-quark mass, the renormalization scale, and the NRQCD matrix elements.

scholarly journals CHARMONIUM POLARIZATION AT THE TEVATRON

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 483-485
Author(s):  
JUNGIL LEE
Keyword(s):  
Factorization Approach ◽  
Qcd Factorization ◽  
Nonrelativistic Qcd

The current issues on the polarization of prompt J/ψ at the Tevatron is discussed. The prediction based on the nonrelativistic QCD factorization approach agrees with measurements from the CDF collaboration at intermediate values of pT, but disagrees at the large values of pT measured.

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