Production properties of deuterons, helions and tritons via an analytical nucleon coalescence method in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV

TL;DR

This paper enhances a nucleon coalescence model to include coordinate-momentum correlations, applying it to Pb-Pb collisions at 2.76 TeV to analyze light nuclei production and compare with experimental data.

Contribution

It introduces an improved coalescence model with coordinate-momentum correlations and provides analytical formulas for coalescence factors in heavy-ion collisions.

Findings

Successfully reproduces spectra and yields of light nuclei

Explains coalescence factors' dependence on collision centrality and momentum

Provides yield ratios useful for distinguishing production mechanisms

Abstract

We improve a nucleon coalescence model to include the coordinate-momentum correlation in nucleon joint distributions, and apply it to Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV to study production properties of deuterons ($d$), helions ($^3$He) and tritons ($t$). We give formulas of the coalescence factors $B_2$ and $B_3$, and naturally explain their behaviors as functions of the collision centrality and the transverse momentum per nucleon $p_T/A$. We reproduce the transverse momentum spectra, averaged transverse momenta and yield rapidity densities of $d$, $^3$He and $t$, and find the system effective radius obtained in the coalescence production of light nuclei behaves similarly to Hanbury Brown-Twiss interferometry radius. We particularly give expressions of yield ratios $d/p$, $^3$He$/d$, $t/p$, $^3$He$/p$, $d/p^{2}$, $^3$He$/p^3$, $t/^3$He and argue their nontrivial behaviors can be used to distinguish production mechanisms of light nuclei.