Elliptic flow of thermal dileptons in relativistic nuclear collisions

Chatterjee, Rupa; Srivastava, Dinesh K.; Heinz, Ulrich W.; Gale, Charles

Elliptic flow of thermal dileptons in relativistic nuclear collisions

Authors

Chatterjee, Rupa

Srivastava, Dinesh K.

Heinz, Ulrich W.

Gale, Charles

Description

We calculate the transverse momentum and invariant mass dependence of elliptic flow of thermal dileptons for Au+Au collisions at the Relativistic Heavy Ion Collider. The system is described using hydrodynamics, with the assumption of formation of a thermalized quark-gluon plasma at some early time, followed by cooling through expansion, hadronization and decoupling. Dileptons are emitted throughout the expansion history: by annihilation of quarks and anti-quarks inthe early quark-gluon plasma stage and through a set of hadronic reactions during the late hadronic stage. The resulting differential elliptic flow exhibits a rich structure, with different dilepton mass windows providing access to different stages of the expansion history. Elliptic flow measurements for dileptons,combined with those of hadrons and direct photons, are a powerful tool for mapping the time-evolution of heavy-ion collisions.
Latex 8 pages including a total of 13 postscript figures. Added 2 figures, additional references, and expanded discussions. Figures modified for better viewing. To appear in Phys. Rev. C