Directed flow of lambda hyperons in (2-6 )A GeV Au+Au collisions.
/ Authors
P.Chung, N.N.Ajitanand, J.M.Alexander, M.Anderson, D.Best, F.P.Brady, T.Case, W.Caskey, D.Cebra, J.L.Chance
and 40 more authors
B.Cole, K.Crowe, A.Das, J.E.Draper, M.L.Gilkes, S.Gushue, M.Heffner, A.S.Hirsch, E.L.Hjort, L.Huo, M.Justice, M.Kaplan, D.Keane, J.C.Kintner, J.Klay, D.Krofcheck, R.A.Lacey, J.Lauret, M.A.Lisa, H.Liu, Y.M.Liu, R.McGrath, Z.Milosevich, G.Odyniec, D.L.Olson, S.Y.Panitkin, C.Pinkenburg, N.T.Porile, G.Rai, H.G.Ritter, J.L.Romero, R.Scharenberg, L.Schroeder, B.Srivastava, N.T.BStone, T.J.M.Symons, T.Wienold, R.Witt J.Whitfield, L.Wood, W.N.Zhang
/ Abstract
Directed flow measurements for {Lambda} hyperons are presented and compared to those for protons produced in the same Au+Au collisions (2A, 4A, and 6AGeV; b<5-6 fm ). The measurements indicate that {Lambda} hyperons flow consistently in the same direction but with smaller magnitudes. A strong positive flow [for {Lambda} s] has been predicted in calculations which include the influence of the {Lambda} -nucleon potential. The experimental flow ratio {Lambda}/p is in qualitative agreement with expectations ({approx}2/3 ) from the quark counting rule at 2AGeV but is found to decrease with increasing beam energy.
Journal: Physical Review Letters