Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Effect of $α$-clusters on particle production in O$-$O and p$-$O collisions at LHC energies

Deependra Sharma, Arpit Singh, Md. Samsul Islam, Basanta Nandi, Sadhana Dash

TL;DR

This study investigates whether an $\alpha$-cluster geometry in $^{16}$O leaves imprints on final-state particle production in high-energy O-O and p-O collisions using the PYTHIA/Angantyr framework without hydrodynamics. It implements a tetrahedral $\alpha$-cluster arrangement and compares it to a 3pF Woods-Saxon baseline to assess sensitivity to initial-state geometry in observables such as pseudorapidity and transverse momentum spectra, including strange and heavy-flavor hadrons. The results show that the $\alpha$-cluster configuration yields a more compact radial density and typically larger $\langle N_{part} \rangle$ in non-central events, leading to higher charged-particle yields and modest hardening of $p_T$ spectra, especially at forward rapidities. The findings suggest potential for imaging nuclear shapes via high-energy collision data and indicate future work with color reconnection and rope hadronization to further enhance sensitivity to initial-state geometry.

Abstract

In the present work, O$-$O collisions at $\sqrt{s_{NN}}$ = 7 TeV and p$-$O collisions at $\sqrt{s_{NN}}$ = 9.9 TeV are studied using PYTHIA8/Angantyr model for heavy-ion collisions. The theoretically predicted $α$-cluster structure of oxygen nucleus is implemented in the model to investigate the effect of initial configuration of oxygen nucleus on final state observables. The results obtained from $α$-cluster structure are compared with those obtained from Woods-Saxon nuclear charge density distribution. The Angantyr model simulation showed that the radial distribution of oxygen nucleus in $α$-cluster configuration is more compact in comparison to the Woods-Saxon distribution. The results on charged and identified particle pseudorapidity distribution is obtained in the two initial state configuration of the oxygen nucleus. The results demonstrated that the effect of initial geometrical configuration is more distinct in the non-central collisions in comparison to the central collisions for both O$-$O and p$-$O collisions.

Effect of $α$-clusters on particle production in O$-$O and p$-$O collisions at LHC energies

TL;DR

This study investigates whether an -cluster geometry in O leaves imprints on final-state particle production in high-energy O-O and p-O collisions using the PYTHIA/Angantyr framework without hydrodynamics. It implements a tetrahedral -cluster arrangement and compares it to a 3pF Woods-Saxon baseline to assess sensitivity to initial-state geometry in observables such as pseudorapidity and transverse momentum spectra, including strange and heavy-flavor hadrons. The results show that the -cluster configuration yields a more compact radial density and typically larger in non-central events, leading to higher charged-particle yields and modest hardening of spectra, especially at forward rapidities. The findings suggest potential for imaging nuclear shapes via high-energy collision data and indicate future work with color reconnection and rope hadronization to further enhance sensitivity to initial-state geometry.

Abstract

In the present work, OO collisions at = 7 TeV and pO collisions at = 9.9 TeV are studied using PYTHIA8/Angantyr model for heavy-ion collisions. The theoretically predicted -cluster structure of oxygen nucleus is implemented in the model to investigate the effect of initial configuration of oxygen nucleus on final state observables. The results obtained from -cluster structure are compared with those obtained from Woods-Saxon nuclear charge density distribution. The Angantyr model simulation showed that the radial distribution of oxygen nucleus in -cluster configuration is more compact in comparison to the Woods-Saxon distribution. The results on charged and identified particle pseudorapidity distribution is obtained in the two initial state configuration of the oxygen nucleus. The results demonstrated that the effect of initial geometrical configuration is more distinct in the non-central collisions in comparison to the central collisions for both OO and pO collisions.

Paper Structure

This paper contains 10 sections, 1 equation, 11 figures, 1 table.

Table of Contents

  1. Introduction
  2. Model description
  3. Angantyr Model
  4. $\alpha$-cluster structure implementation in $^{16}$O
  5. Woods-Saxon Distribution
  6. Results and Discussions
  7. Pseudorapidity Distributions
  8. Transverse Momentum Distributions
  9. Conclusions
  10. Acknowledgement

Figures (11)

  • Figure 1: A three-dimensional view of the (a)$\alpha$-cluster structure, and (b) Woods-Saxon nuclear charge density distribution for $^{16}$O nucleus.
  • Figure 2: Distribution of nucleons in the transverse (x-y) plane for (a) $\alpha$-cluster structure, and (b) Woods-Saxon nuclear charge density distribution for $^{16}$O nucleus.
  • Figure 3: Radial profile for distribution of the nucleons in the $^{16}$O nucleus for $\alpha$-cluster structure and Woods-Saxon nuclear charge density distribution.
  • Figure 4: Pseudorapidity distribution of charged particles produced in O$-$O collisions at $\sqrt{s_{NN}}$ = 7 TeV for (a) 0-5%, (b) 20-40%, and (c) 60-80% centrality intervals for $\alpha$-cluster structure and Woods-Saxon nuclear charge density distribution.
  • Figure 5: Pseudorapidity distribution of charged particles produced in p$-$O collisions at $\sqrt{s_{NN}}$ = 9.9 TeV for (a) 0-5%, (b) 20-40%, and (c) 60-80% centrality intervals for $\alpha$-cluster structure and Woods-Saxon nuclear charge density distribution.
  • ...and 6 more figures