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Title: Use of a running coupling in the NLO calculation of forward hadron production

Abstract

We address and solve a puzzle raised by a recent calculation [1] of the cross section for particle production in proton-nucleus collisions to next-to-leading order: the numerical results show an unreasonably large dependence upon the choice of a prescription for the QCD running coupling, which spoils the predictive power of the calculation. Specifically, the results obtained with a prescription formulated in the transverse coordinate space differ by 1 to 2 orders of magnitude from those obtained with a prescription in momentum space. We show that this discrepancy is an artifact of the interplay between the asymptotic freedom of QCD and the Fourier transform from coordinate space to momentum space. When used in coordinate space, the running coupling can act as a fictitious potential which mimics hard scattering and thus introduces a spurious contribution to the cross section. We identify a new coordinate-space prescription, which avoids this problem, and leads to results consistent with those obtained with the momentum-space prescription.

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Columbia Univ., New York, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1427315
Alternate Identifier(s):
OSTI ID: 1501646
Grant/Contract Number:  
FG02-92ER40699
Resource Type:
Published Article
Journal Name:
Physical Review D
Additional Journal Information:
Journal Name: Physical Review D Journal Volume: 97 Journal Issue: 5; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats

Ducloué, B., Iancu, E., Lappi, T., Mueller, A. H., Soyez, G., Triantafyllopoulos, D. N., and Zhu, Y. Use of a running coupling in the NLO calculation of forward hadron production. United States: N. p., 2018. Web. doi:10.1103/PhysRevD.97.054020.
Ducloué, B., Iancu, E., Lappi, T., Mueller, A. H., Soyez, G., Triantafyllopoulos, D. N., & Zhu, Y. Use of a running coupling in the NLO calculation of forward hadron production. United States. doi:10.1103/PhysRevD.97.054020.
Ducloué, B., Iancu, E., Lappi, T., Mueller, A. H., Soyez, G., Triantafyllopoulos, D. N., and Zhu, Y. Tue . "Use of a running coupling in the NLO calculation of forward hadron production". United States. doi:10.1103/PhysRevD.97.054020.
@article{osti_1427315,
title = {Use of a running coupling in the NLO calculation of forward hadron production},
author = {Ducloué, B. and Iancu, E. and Lappi, T. and Mueller, A. H. and Soyez, G. and Triantafyllopoulos, D. N. and Zhu, Y.},
abstractNote = {We address and solve a puzzle raised by a recent calculation [1] of the cross section for particle production in proton-nucleus collisions to next-to-leading order: the numerical results show an unreasonably large dependence upon the choice of a prescription for the QCD running coupling, which spoils the predictive power of the calculation. Specifically, the results obtained with a prescription formulated in the transverse coordinate space differ by 1 to 2 orders of magnitude from those obtained with a prescription in momentum space. We show that this discrepancy is an artifact of the interplay between the asymptotic freedom of QCD and the Fourier transform from coordinate space to momentum space. When used in coordinate space, the running coupling can act as a fictitious potential which mimics hard scattering and thus introduces a spurious contribution to the cross section. We identify a new coordinate-space prescription, which avoids this problem, and leads to results consistent with those obtained with the momentum-space prescription.},
doi = {10.1103/PhysRevD.97.054020},
journal = {Physical Review D},
number = 5,
volume = 97,
place = {United States},
year = {2018},
month = {3}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1103/PhysRevD.97.054020

Citation Metrics:
Cited by: 4 works
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