Single-parton scattering versus double-parton scattering in the production of two $c \bar c$ pairs and charmed meson correlations at the LHC

Understand

We compare results of exact calculations of single parton scattering (SPS) and double parton scattering (DPS) for production of $c \bar c c \bar c$ and for $D$ meson correlations.

• The SPS calculations are performed in collinear approximation with exact matrix element for $g g \to c \bar c c \bar c$ and $q \bar q \to c \bar c c \bar c$ subprocesses.
• It is shown that the contribution of gluon-gluon subprocess is about factor 50 larger than that for quark-antiquark annihilation.
• The new results are compared with results of previous calculation with the approximate matrix element for $g g \to c \bar c c \bar c$ in the high-energy approximation.