Measurement of the azimuthal anisotropy of charged particles in √sNN = 5.36 TeV 16O+16O and 20Ne+20Ne collisions with the ATLAS detector


Aad G., Aakvaag E., Abbott B., Abdelhameed S., Abeling K., Abicht N., ...Daha Fazla

Physical Review C, cilt.113, sa.4, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 113 Sayı: 4
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1103/xqxz-8bhf
  • Dergi Adı: Physical Review C
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, INSPEC
  • İstanbul Üniversitesi Adresli: Evet

Özet

This paper presents the first measurements of the azimuthal anisotropy coefficients vn, which quantify the nth-order Fourier modulation of charged-particle azimuthal distributions, for n = 2−4 in √sNN = 5.36 TeV 16O+16O and 20Ne+20Ne collisions recorded with the ATLAS detector at the CERN Large Hadron Collider in 2025. The vn coefficients are measured as a function of transverse momentum (pT), collision centrality, and event multiplicity. They are extracted using two complementary methods: two-particle correlations with a template-fit subtraction of short-range nonflow contributions, and four-particle subevent cumulants, which intrinsically suppress nonflow effects and provide sensitivity to flow fluctuations. The results show a clear hierarchy v2?> v3?> v4 and a nonmonotonic dependence on pT, reaching a maximum around 2 GeV, consistent with trends observed in heavy-ion collisions. Detailed comparisons between the two collision systems reveal an enhanced v2 in central 20Ne+20Ne collisions, consistent with theory expectations based on the predicted prolate deformation of neon nuclei, in contrast to the slightly tetrahedral structure predicted for oxygen. The four-particle cumulant results highlight strong event-by-event fluctuations and provide the greatest sensitivity to nuclear shape effects. These measurements can place new constraints on the initial geometry and the hydrodynamic response in light-ion collisions, offering valuable input for models of nuclear structure.