The striking collectivity like behavior found in high-multiplicity proton-proton (pp) collisions and ultra-peripheral collisions (UPC) at the LHC challenges our conventional wisdom on the formation of the quark-gluon plasma (QGP). A microscopic explanation to the origin of collectivity in these collision systems at rather small scales will help us understand the mechanism that leads to the...
The second-order Fourier coefficients ($v_{2}$) are expected to reflect the overlap region of colliding heavy ions. However, a non-zero $v_{2}$ has been observed in high-multiplicity pp and pPb collisions where overlap does not exist. The CMS experiment collected data at a nucleon-nucleon center-of-mass energies 5.02 and 8.16 TeV for PbPb and pPb collisions, respectively. The dimuons were used...
Quarkonium production in small systems has been extensively studied in LHC and RHIC to understand the suppression effects which may be described by the existence of a small QGP droplet. To further elaborate, it is necessary to obtain experimental data where models can describe the suppression from the hot medium effect and the cold nuclear matter effect. In this talk, we present recent studies...
We employ a detailed transport model coupled with realistic hydrodynamics in heavy-ion collisions to study the anisotropic flows of charmonium, including directed flow, elliptic flow, and triangular flows. The directed flow ($v_1$) of $J/\psi$ is induced by the rapidity-odd initial energy density, which arises from the rotation of the quark-gluon plasma (QGP). Meanwhile, the elliptic flow...
The rapid longitudinal expansion characteristic of heavy-ion collisions leads to universal attractor behavior of the resulting drop of Quark-Gluon Plasma already at very early times. Assuming approximate boost invariance, we incorporate transverse dynamics and parton evolution by linearizing the Mueller-Israel-Stewart theory around the attractor. This yields a system of coupled ordinary...
