Azimuthal asymmetry at large $p_t$ seem to be too large for a pure “jet quenching”

We discuss a simple generic model of “jet quenching” in which matter absorption is defined by one parameter. We show that as absorption grows, the azimuthal asymmetry parameter $v_2$ grows as well, reaching the finite limit $v_2^{*}$ which has a simple geometric interpretation. We show that this limit is still below the experimental values for $6>\mathrm{}{p}_t>2\mathrm{}\hspace{0.5em}\mathrm{GeV},$ according to preliminary data from the STAR experiment at RHIC. We thus conclude that jet quenching models alone cannot account for the observed phenomenon, and speculate about alternative scenarios.