The tomography of quark-gluon plasma by vector mesons

Abstract

The fireball formed in a heavy ion collision is characterized by the impact parameter vector $\vec b$, which is orthogonal to the beam direction and can be determined from the multiplicity and the angular distribution of the reaction products. By appropriate rotations the $\vec b$vectors of each collision can be oriented into a fixed direction. Using the measured values of the momentum distributions of the vector mesons an integral equation can be formulated for the unknown emission densities $(E_M (\vec r))$ and for the unknown absorption densities $(\Delta \mu _M (\vec r,p))$ of the different vector mesons $M( \equiv \omega ^0 ,\rho ^0 ,\phi ^0 ,\psi ^0 ,\psi ^{0'} ,\Upsilon )$.