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arXiv · 2206.06987

Asymptotic gluon density within the color dipole picture in the light of HERA high-precision data

D. A. Fagundes·M. V. T. Machado
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Abstract

We present an analysis of the most precise set of HERA data within the color dipole formalism, by using an analytical gluon density, based on the double-logarithm approximation of the DGLAP equations in the asymptotic limit of the scaling variable, $\sigma=\log{(1/x)}\log{(\log{(Q^2/Q_ 0^2)})}\rightarrow \infty$. Fits to data, including charm and bottom quarks are performed and demonstrate the efficiency of the model in describing the reduced cross section, $\sigma_{r}$, in the wide range $Q^2:(1.5,500)$ GeV$^2$ for two dipole models including parton saturation effects. We also give predictions to $F_{2}^{c\bar{c}}$ , $F_{2}^{b\bar{b}}$ and $F_{L}$, all describing the data reasonably well in the range $Q^2:(2.5,120)$ GeV$^2$. Total cross sections of exclusive photoproduction of $J/\psi$ and $\rho$ are also calculated and successfully compared to HERA data and recent measurements at LHCb.

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D. A. Fagundes, M. V. T. Machado. 2022-06-14. Asymptotic gluon density within the color dipole picture in the light of HERA high-precision data. https://doi.org/10.1103/physrevd.107.014004

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