Studies of di-jet survival and surface emission bias in Au+Au collisions   via angular correlations with respect to back-to-back leading hadrons
  We report first results from an analysis based on a new multi-hadron correlation technique, exploring jet-medium interactions and di-jet surface emission bias at RHIC. Pairs of back-to-back high transverse momentum hadrons are used for triggers to study associated hadron distributions. In contrast with two- and three-particle correlations with a single trigger with similar kinematic selections, the associated hadron distribution of both trigger sides reveals no modification in either relative pseudo-rapidity or relative azimuthal angle from d+Au to central Au+Au collisions. We determine associated hadron yields and spectra as well as production rates for such correlated back-to-back triggers to gain additional insights on medium properties. 
H. Agakishiev, M.M. Aggarwal, Z. Ahammed, A.V. Alakhverdyants, I.   Alekseev, J. Alford, B.D. Anderson, C.D. Anson, D. Arkhi...
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