Addressing the physics of the ridge by 2 and 3-particle correlations at STAR

Collaboration
for the collaboration.
Jul, 2009

Citations per year

20092010201120123201
Abstract: (Elsevier)
We present new results on 2-particle azimuthal (Δ ϕ ) correlation relative to event plane and 3-particle pseudorapidity (Δ η ) correlation at mid-rapidity in Au+Au collisions at s N N = 200   GeV , measured by the STAR experiment. While jet-like correlation is symmetric, ridge is found to be asymmetric when trigger particle azimuth is between in- and out-of-plane. The charge ordering properties between associated and trigger particles are exploited to separate jet-like and ridge contributions in 3-particle Δ η -Δ η correlations. We found that like-sign triplets are dominated by ridge. The separated ridge, while narrow in Δ ϕ , is extremely broad in Δ η . The ridge particles are not only uncorrelated to the trigger particle in Δ η , but also uncorrelated between themselves.
Note:
  • 4 pages, 4 Figures, Quark Matter 2009