Mach-cone shock waves were proposed to explain the broad and perhaps
double-peaked away-side 2-particle jet-correlations at RHIC; however, other
mechanisms cannot be ruled out. Three-particle jet-correlation is needed in
order to distinguish various physics mechanisms. In this talk the 3-particle
jet-correlation measurements are presented and their implications are
discussed.Comment: 3 figures. Proceedings of "Quark Confinement and the Hadron Spectrum
VII 2006", Ponta Delgada, 2-7 September 200
