Low x gluons determined by open charm production

E. G. de Oliveira; A. D. Martin; M. G. Ryskin

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arXiv · 1705.08845

Low x gluons determined by open charm production

E. G. de Oliveira·A. D. Martin·M. G. Ryskin

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Abstract

We use the LHCb data on the forward production of $D$ mesons at 7, 13 and 5 TeV to make a direct determination of the gluon distribution, $xg$, at NLO in the $10^{-5} \lesssim x \lesssim 10^{-4}$ region. We first use a simple parametrization of the gluon density in each of the four transverse momentum intervals of the detected $D$ mesons. Second, we use a double log parametrization to make a combined fit to all the LHCb $D$ meson data. The values found for $xg$ in the above $x$ domain are of the similar magnitude (or a bit larger) than the central values of extrapolations of the gluons obtained by the global PDF analyses into this small $x$ region. However, in contrast, we find $xg$ has a weak dependence on $x$.

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E. G. de Oliveira, A. D. Martin, M. G. Ryskin. 2017-05-24. Low x gluons determined by open charm production. https://arxiv.org/abs/1705.08845

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