Connected and disconnected sea partons from the CT18 parametrization of PDFs

The separation of the connected and disconnected sea partons, which were uncovered in the Euclidean path-integral formulation of the hadronic tensor, is accommodated with an extended parametrization of the nonperturbative parton distribution functions in the CT18 global analysis. This is achieved with the help of the distinct small x behaviors of these two sea partons and the constraint from the lattice calculation of the ratio of the strange momentum fraction to that of the u over bar or d over bar in the disconnected insertion. The whole dataset of CT18 is used in this CT18CS fit. The impact of the recent SeaQuest data on the d over bar (x) - u over bar (x) distribution of CT18CS is also discussed. The separate momentum fractions for the valence, the connected sea and disconnected sea of u and d, the strange and the gluon partons are presented at the input scale mu = 1.3 GeV for the first time. They can be compared term-by-term with systematic error controlled lattice calculations.

Automated summary

The separation of connected and disconnected sea partons is achieved through an extended parametrization of the nonperturbative parton distribution functions in the CT18 global analysis. The dataset of CT18 is utilized in the CT18CS fit, and the impact of recent SeaQuest data on CT18CS is discussed. The separate momentum fractions for various partons are presented for the first time at the input scale mu = 1.3 GeV.