An η-elongated same-side 2D peak ("soft ridge") in minimum-bias angular
correlations from heavy ion collisions has been attributed both to jet
formation and to initial-state geometry structure coupled to radial flow. We
consider evidence for both interpretations.Comment: 4 pages, 3 figures, to be published in the Proceedings of the XLI
International Symposium on Multiparticle Dynamics (ISMD 2011), 26-30
September, 2011, Miyajima Island, Hiroshima, Japa