Methods for separation of deuterons produced in the medium and in jets in high energy collisions

TL;DR

This paper models deuteron production in high-energy proton-proton collisions by applying a coalescence afterburner to PYTHIA-generated protons and neutrons, and proposes methods to distinguish jet-related deuterons from those produced in the medium.

Contribution

It introduces a novel application of coalescence modeling to jet environments in high-energy collisions and suggests experimental observables to separate jet and medium contributions.

Findings

PYTHIA reproduces proton spectra well.

The deuteron spectrum from the model agrees with experimental data.

The coalescence parameter B2 increases with momentum, consistent with jet coalescence.

Abstract

Coalescence has long been used to describe the production of light (anti-)nuclei in heavy ion collisions. The same underlying mechanism may also exist in jets when a proton and a neutron are close enough in phase space to form a deuteron. We model deuteron production in jets by applying an afterburner to protons and neutrons produced in PYTHIA for $p$+$p$ collisions at a center of mass energy $\sqrt{s} =$ 7 TeV. PYTHIA provides a reasonable description of the proton spectra and the shape of the deuteron spectrum predicted by the afterburner is in agreement with the data. We show that the rise in the coalescence parameter $B_2$ with momentum observed in data is consistent with coalescence in jets. We show that di-hadron correlations can be used to separate the contributions from the jet and the underlying event. This model predicts that the conditional coalescence parameter in the jet-like correlation should be independent of the trigger momentum.