Production of associated $\Upsilon$ and open charm hadrons in $pp$ collisions at $\sqrt{s}=7$ and $8$TeV via double parton scattering

TL;DR

This paper reports the first observation of associated production of bottomonia and open charm hadrons in proton-proton collisions at 7 and 8 TeV, highlighting double parton scattering as the dominant production mechanism.

Contribution

It provides the first measurements of associated bottomonia and open charm production in $pp$ collisions, emphasizing the role of double parton scattering.

Findings

Observation of five bottomonia-charm hadron combinations.

Measurement of production cross-sections for specific pairs.

Evidence that double parton scattering dominates the production process.

Abstract

Associated production of bottomonia and open charm hadrons in $pp$ collisions at $\sqrt{s}=7$ and $8$TeV is observed using data corresponding to an integrated luminosity of 3$fb^{-1}$ accumulated with the LHCb detector. The observation of five combinations, $\Upsilon(1S)D^0$, $\Upsilon(2S)D^0$, $\Upsilon(1S)D^+$, $\Upsilon(2S)D^+$ and $\Upsilon(1S)D^+_{s}$, is reported. Production cross-sections are measured for $\Upsilon(1S)D^0$ and $\Upsilon(1S)D^+$ pairs in the forward region. The measured cross-sections and the differential distributions indicate the dominance of double parton scattering as the main production mechanism. This allows a precise measurement of the effective cross-section for double parton scattering.