Bottomonium suppression and elliptic flow in an anisotropic quark-gluon plasma using the quantum trajectories method

Abstract

We study bottomonium dynamics in a momentum-space anisotropic quark-gluon plasma (QGP) using the quantum trajectories (QTraj) framework. The real part of the heavy-quark potential is obtained from a minimal extension of the Karsch-Mehr-Satz (KMS) potential, while the angle-averaged imaginary part is derived to leading order in the anisotropy parameter $\xi$ and modeled to interpolate smoothly between the small- and large -$\xi$ regimes. The resulting anisotropic complex potential is used to solve the real-time Schrödinger equation using QTraj for the evolution of bottomonium in heavy-ion collisions. Nuclear modification factors $R_{AA}$, double ratios, and elliptic flow coefficients $v_2$ for the ${\rm Y}(1S)$, ${\rm Y}(2S)$, and ${\rm Y}(3S)$ states are computed, including feed-down contributions, in Pb-Pb collisions at $\sqrt{s_{NN}}=5.02\text{TeV}$. The QTraj-Aniso predictions successfully reproduce the observed sequential suppression pattern and non-zero elliptic flow, while for $R_{AA}$ and double ratios, the anisotropic implementation provides a modest but systematic improvement over the isotropic baseline, moving the predictions closer to experimental measurements from the ALICE, ATLAS, and CMS collaborations and further demonstrating the relevance of path-length dependent suppression and medium anisotropy in quarkonium phenomenology.

Comments: 30 pages, 9 figures. Revised version includes comparison of isotropic and anisotropic predictions; discussion and conclusions updated accordingly