Research Information System
PHYSICS LETTERS B, vol.876, 2026 (SCI-Expanded, Scopus)
For the first time, correlations among mixed-order moments of two or three flow harmonics -(v(n)(k) , v(m)(l) ) and (v(n)(k) , v(m)(l) , v(p)(q)), with k, l, and q denoting the respective orders-are measured in xenon-xenon (XeXe) collisions and compared with lead-lead (PbPb) results, providing a novel probe of collective behavior in heavy ion collisions. These measurements compare a nearly spherical, doubly-magic Pb-208 nucleus to a triaxially deformed Xe-129 nucleus, emphasizing the sensitivity to initial-state geometry fluctuations arising from nuclear deformation. The dependence of these results (v(n) , n = 2, 3, 4) on the shape and size of the nuclear overlap region is studied. Comparisons between v(2) , v(3) , and v(4) demonstrate the importance of v(3) and v(4) in exploring the nonlinear hydrodynamic response of the quark-gluon plasma (QGP) to the initial spatial anisotropy. The results constrain initial-state model parameters that influence the evolution of the QGP. The CMS detector was used to collect XeXe and PbPb data at nucleon-nucleon center-of-mass energies of root SNN = 5.44 and 5.36 TeV, respectively. Correlations are extracted using multiparticle mixed-harmonic cumulants (up to eight-particle cumulants) with charged particles in the pseudorapidity range I eta I <2.4 and transverse momentum range 0.5 < p(r)<3 GeV/c.