Testing production scenarios for (anti-)(hyper-)nuclei and exotica at energies available at the CERN Large Hadron Collider

Abstract

We present a detailed comparison of coalescence and thermal-statistical models for the production of (anti-)(hyper-)nuclei in high-energy collisions. For the first time, such a study is carried out as a function of the size of the object relative to the size of the particle emitting source. Our study reveals large differences between the two scenarios for the production of objects with extended wavefunctions. While both models give similar predictions and show similar agreement with experimental data for (anti-)deuterons and (anti-) 3 He nuclei, they largely differ in their description of (anti-)hypertriton production. We propose to address experimentally the comparison of the production models by measuring the coalescence parameter systematically for different (anti-)(hyper-)nuclei in different collision systems and differentially in multiplicity. Such measurements are feasible with the current and upgraded Large Hadron Collider experiments. Our findings highlight the unique potential of ultra-relativistic heavy-ion collisions as a laboratory to clarify the internal structure of exotic QCD objects and can serve as a basis for more refined calculations in the future. arXiv:1807.05894v3 [hep-ph]

Nucleosynthesis in heavy-ion collisions at the LHC via the Saha equation

“…Common approaches used to describe the production of these loosely-bound objects include the thermal-statistical approach [4][5][6][7][8] and the coalescence model [9][10][11][12], a determination of the production mechanism is of great interest [see, e.g., Refs. [13][14][15][16][17][18][19][20] for recent results within these two approaches]. The measured yields have been observed to agree remarkably well with a thermal model calculation at a temperature T ch 155 MeV of the conventional chemical freeze-out of hadrons [21][22][23], while the available transverse momentum spectra of both nuclei and stable hadrons are characterized by a lower kinetic freeze-out temperature T kin 100 − 115 MeV [1].…”

Production of (anti-)He3 and (anti-)H3Acharya1, Adamová2, Adler3 et al. 2020Phys. Rev. C262160View full textAdd to dashboardCite

“…However, recent studies [5] have shown a sizable difference for the B A parameter as a function of the size of the particle emitting source between predictions by the SHM with kinetic freeze-out conditions from a simple hydrodynamical model and the coalescence model. Here, information from Hanbury Brown-Twiss (HBT) correlations is used to determine the source size.…”

“…is the invariant yield of protons, which is expected to be identical to that of neutrons at midrapidity and LHC energies [5]. Here, the coalescence probability is given by the parameter B A .…”

“…Thus, the ideal benchmark would be to study the production of hypertriton ( 3 H) as a function of the mean charged-particle multiplicity density, which is not yet possible due to the size of the data sets available. Thus, the difference between the production of 3 He and 3 H was studied, which is expected to offer similar insight on the comparison of the SHM and the coalescence approaches, especially for smaller collision systems [5,10]. The production yields for (anti-) 3 He in pp and Pb-Pb [11,12] collisions measured by ALICE do not cover completely the evolution from small to large source sizes.…”

Measurement of the Low-Energy Antideuteron Inelastic Cross Section

“…At the LHC, the ALICE Collaboration has studiedp,d, 3H e, and 4H e production in pp, p-Pb, and Pb-Pb collisions at center-of-mass energies per nucleon pair from 0.9 to 13 TeV [26][27][28][29][30][31][32], and the yields obtained for A ≥ 2 have been interpreted by means of coalescence or statistical hadronization models [33][34][35][36]. The LHC measurements combined with different coalescence models have been employed to estimate the antideuteron and antihelium flux from cosmic-ray interactions measurable by the AMS-02 and GAPS experiments [15,[37][38][39].…”