The Azimuthal Asymmetry at large p_t seem to be too large for a ``Jet Quenching''

Abstract

We discuss simple generic model of ``jet quenching'' in which matter absorption is defined by one parameter. We show that as absorption grows, the azimuthal asymmetry v_2 grows as well, reaching the finite limit with a simple geometric interpretation. It turns out, that this limit is still below the experimental values for 6 > p_t > 2 GeV, according to preliminary data from STAR experiment at RHIC. We thus conclude that ``jet quenching'' models alone cannot account for the observed phenomenon, and speculate about alternative scenarios.

Comments: 3 pages, 2 figs, 1 table. The final version contaning note added in proofs for PRC, which reflects experimental development which seem to suggest that the geometrical model for v2 is in fact correct description of data at pt=2-10 GeV