Testing Production Scenarios for (Anti-)(Hyper-)nuclei with Multiplicity-dependent Measurements at the LHC

F Bellini,A.P Kalweit

doi:10.5506/aphyspolb.50.991

Abstract

The production of light anti- and hyper-nuclei provides unique observables to characterise the system created in high energy proton-proton (pp), proton-nucleus (pA) and nucleus-nucleus (AA) collisions. In particular, nuclei and hyper-nuclei are special objects with respect to non-composite hadrons (such as pions, kaons, protons, etc.), because their size is comparable to a fraction or the whole system created in the collision. Their formation is typically described within the framework of coalescence and thermal-statistical production models. In order to distinguish between the two production scenarios, we propose to measure the coalescence parameter B$_{A}$ for different anti- and hyper-nuclei (that differ by mass, size and internal wave-function) as a function of the size of the particle emitting source. The latter can be controlled by performing systematic measurements of light (anti-)(hyper-)nuclei in different collision systems (pp, pA, AA) and as a function of the multiplicity of particles created in the collision. While it is often argued that the coalescence and the thermal model approach give very similar predictions for the production of light nuclei in heavy-ion collisions, our study shows that large differences can be expected for hyper-nuclei with extended wave-functions, as the hyper-triton. We compare the model predictions with data from the ALICE experiment and we discuss perspectives for future measurements with the upgraded detectors during the High-Luminosity LHC phase in the next decade.

Highlights

Within the Color Glass Condensate (CGC) framework, the hybrid formalism [1] is used to study single inclusive particle production at next-toleading order [2,3,4,5,6,7,8,9,10] and heavy-quark production [11] at forward rapidity
The dense target is treated in the CGC, i.e. it is defined as a distribution of strong color fields, which during the scattering transfer transverse momentum to the propagating partonic configuration
The usual approach is to calculate the cross section in the CGC, after which one takes the small dipole or correlation limit which corresponds to a leading-power expansion in the ratio p2t /Q2 of the hard scales with Λ2QCD p2t Q2

Summary

Introduction

Within the Color Glass Condensate (CGC) framework, the hybrid formalism [1] is used to study single inclusive particle production at next-toleading order [2,3,4,5,6,7,8,9,10] and heavy-quark production [11] at forward rapidity. In this set-up, the wave function of the projectile proton is treated in the spirit. Non-perturbative models such as the McLerran–Venugopalan (MV) [23] or Golec-Biernat–Wüsthoff (GBW) model [24] can be used to write down analytical expressions

Production cross section

Correlation limit and gluon TMDs

Conclusions