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It is common lore that Parton Distribution Functions (PDFs) in the $\overline{\rm { MS}}$ factorization scheme can become negative beyond leading order due to the collinear subtraction which is needed in order to define partonic cross sections.
G. Curci, W. Furmanski, and R. Petronzio, “Evolution of Parton Densities Beyond Leading Order: The Nonsinglet Case,” Nucl. Phys
1980
Earlier work this paper cites.
J. C. Collins and D. E. Soper, “Parton Distribution and Decay Functions,” Nucl. Phys
1982
Earlier work this paper cites.
G. F. Sterman, “Summation of Large Corrections to Short Distance Hadronic Cross-Sections,” Nucl. Phys
1987
Earlier work this paper cites.
M. Diemoz, F. Ferroni, E. Longo, and G. Martinelli, “Parton Densities from Deep Inelastic Scattering to Hadronic Processes at Super Collider Energies,” Z. Phys. C
1988
Earlier work this paper cites.
S. Catani and L. Trentadue, “Resummation of the QCD Perturbative Series for Hard Processes,” Nucl. Phys
1989
Earlier work this paper cites.
M. Aivazis, J. C. Collins, F. I. Olness, and W.-K. Tung, “Leptoproduction of heavy quarks. 2. A Unified QCD formulation of charged and neutral current processes from fixed target to collider energies,” Phys. Rev. D
1994
Earlier work this paper cites.
R. K. Ellis, W. J. Stirling, and B. R. Webber, “QCD and collider physics,” Camb. Monogr. Part. Phys. Nucl. Phys. Cosmol
1996
Earlier work this paper cites.
S. Catani, “Comment on quarks and gluons at small x and the SDIS factorization scheme,” Z. Phys. C
1996
Earlier work this paper cites.
G. Altarelli, S. Forte, and G. Ridolfi, “On positivity of parton distributions,” Nucl. Phys
1998
Cited alongside, same era.
S. Forte, G. Altarelli, and G. Ridolfi, “Are parton distributions positive?,” Nucl. Phys. Proc. Suppl
1998
Cited alongside, same era.
M. Buza, Y. Matiounine, J. Smith, and W. van Neerven, “Charm electroproduction viewed in the variable flavor number scheme versus fixed order perturbation theory,” Eur. Phys. J. C
1998
Cited alongside, same era.
S. Albino and R. D. Ball, “Soft resummation of quark anomalous dimensions and coefficient functions in MS-bar factorization,” Phys. Lett
2001
Cited alongside, same era.
S. Forte and G. Ridolfi, “Renormalization group approach to soft gluon resummation,” Nucl. Phys
2003
Cited alongside, same era.
2010
Later among the works it cites.
2012
Later among the works it cites.
Cambridge University Press, 11, 2013
J. Collins, Foundations of perturbative QCD · 2013
Later among the works it cites.
R. D. Ball, M. Bonvini, and L. Rottoli, “Charm in Deep-Inelastic Scattering,” JHEP
2015
Later among the works it cites.
2016
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2009
Cited alongside, same era.
2010
Cited alongside, same era.
Later among the works it cites.
F. Maltoni, “Basics of QCD for the LHC: p p → H + X pp\to H+X as a case study,” CERN Yellow Rep. School Proc
2018
Later among the works it cites.
S. Jadach, “private communications,” 2020
2020
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