From Hydrodynamics to Jet Quenching, Coalescence, and Hadron Cascade: A Coupled Approach to Solving the R-AA circle times v(2) Puzzle

Hydrodynamics and jet quenching are responsible for the elliptic flow v(2) and suppression of large transverse momentum (p(T)) hadrons, respectively, two of the most important phenomena leading to the discovery of a strongly coupled quark-gluon plasma in high-energy heavy-ion collisions. A consistent description of the hadron suppression factor R-AA and v(2), especially at intermediate pT, however, remains a challenge. We solve this long-standing R-AA (R) v(2) puzzle by including quark coalescence for hadronization and final state hadron cascade in the coupled linear Boltzmann transport-hydro model that combines concurrent jet transport and hydrodynamic evolution of the bulk medium. We illustrate that quark coalescence and hadron cascade, two keys to solving the puzzle, also lead to a splitting of v(2) for pions, kaons, and protons in the intermediate p(T) region. We demonstrate for the first time that experimental data on R-AA, v(2), and their hadron flavor dependence from low to intermediate and high pT in high-energy heavy-ion collisions can be understood within this coupled framework.