Is the quark gluon plasma produced in RHIC collisions strongly coupled?
نویسندگان
چکیده
Recent hexadecapole (v4) and elliptic (v2) flow measurements are used to constrain estimates for the degree of local equilibrium, mean free path λ, and the viscosity to entropy density ratio (ηs ) of the plasma produced in Au+Au collisions at √ sNN = 200 GeV. The eccentricity-scaled flow coefficients v2 ε2 and v4 ε4 indicate that the plasma achieves a degree of local equilibrium within ∼ 5 − 10% of the value expected for a fluid with ηs equal to the conjectured lower bound of 1/4π. Estimates for λ and ηs as a function of collision centrality and particle transverse momentum pT , points to transverse expansion dynamics compatible with a strongly coupled low viscosity plasma.
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تاریخ انتشار 2009