Directed Flow of $\hat{I}›$-Hyperons in 2-6 AGeV Au+Au Collisions

Abstract

Directed flow measurements for $\hat{I}›$-hyperons are presented and compared to those for protons produced in the same Au+Au collisions (2, 4, and 6 AGeV; $b<5-6$ fm). The measurements indicate that $\hat{I}›$-hyperons flow consistently in the same direction and with smaller magnitudes than those of protons. Such a strong positive flow [for $\hat{I}›$s] has been predicted in calculations which include the influence of the $\hat{I}›$-nucleon potential. The experimental flow ratio $\hat{I}›$/p is in qualitative agreement with expectations ($\sim 2/3$) from the quark counting rule at 2 AGeV but is found to decrease with increasing beam energy.

5 pages including 4 Figs. Submitted to Phys. Rev. Lett