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arXiv · 1901.06916

Difficulties in the description of Drell-Yan processes at moderate invariant mass and high transverse momentum

Alessandro Bacchetta·Giuseppe Bozzi·Martin Lambertsen·Fulvio Piacenza·Julius Steiglechner·Werner Vogelsang
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Abstract

We study the Drell-Yan cross section differential with respect to the transverse momentum of the produced lepton pair. We consider data with moderate invariant mass Q of the lepton pair, between 4.5 GeV and 13.5 GeV, and similar (although slightly smaller) values of the transverse momentum q_T. We approach the problem by deriving predictions based on standard collinear factorization, which are expected to be valid toward the high-q_T end of the spectrum and to which any description of the spectrum at lower q_T using transverse-momentum dependent parton distributions ultimately needs to be matched. We find that the collinear framework predicts cross sections that in most cases are significantly below available data at high q_T. We discuss additional perturbative and possible non-perturbative effects that increase the predicted cross section, but not by a sufficient amount.

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Alessandro Bacchetta, Giuseppe Bozzi, Martin Lambertsen, Fulvio Piacenza, Julius Steiglechner, Werner Vogelsang. 2019-01-21. Difficulties in the description of Drell-Yan processes at moderate invariant mass and high transverse momentum. https://doi.org/10.1103/physrevd.100.014018

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