Speaker
Description
Xenon (Xe) nuclei are deformed and have a non-zero quadrupole moment, whereas lead (Pb) nuclei are considered spherical in shape. The study of Xe-Xe collisions at a center-of-mass energy per nucleon pair of $\sqrt{s_{_{\mathrm{NN}}}} = 5.44$ TeV opens up a window to study nuclear deformation at LHC. When compared to Pb-Pb collisions at $\sqrt{s_{_{\mathrm{NN}}}} = 5.36$ TeV, one can explore the dependence of the Fourier flow harmonics ($v_{n}$) on the size and initial-state geometry of the colliding systems. For the first time, correlations between higher-order moments ($\langle v_{n}^{k}v_{m}^{l}\rangle$, where $n,m = 2,3,4$ and $k,l = 2,4,6$) between two ($v_{2}$ and $v_{3}$ or $v_{2}$ and $v_{4}$) or even three flow harmonics ($v_{2}$, $v_{3}$ and $v_{4}$) are measured and compared between Xe-Xe and Pb-Pb collisions as a function of collision centrality. These new measurements have been calculated with multiparticle mixed harmonic cumulants (upto 8th order) using charged particles in the wide pseudorapidity region of the CMS detector ($|\mathrm{\eta}| < 2.4$) and in the transverse momentum range of $0.5 < p_\mathrm{T} < 3.0$ GeV/c. The results have also been compared to several theoretical model predictions. The observables measured in this analysis have been used to closely probe the non-linearities between $v_{2}$, $v_{3}$ and $v_{4}$ and their corresponding eccentricities $\epsilon_{2}$, $\epsilon_{3}$ and $\epsilon_{4}$. This not only helps us to constrain the deformation parameters of Xe nuclei, but can also significantly constrain initial-state model parameters and give us a better understanding of the evolution of the quark-gluon plasma created in heavy-ion collisions at LHC.
| Category | Experiment |
|---|---|
| Collaboration (if applicable) | CMS |
