Di-Jet Imbalance Measurements at $\sqrt{s_{NN}} = 200$ GeV at STAR
  We report the first di-jet transverse momentum asymmetry measurements from Au+Au and p+p collisions at RHIC. The two highest-energy back-to-back jets reconstructed from fragments with transverse momenta above 2 GeV/c display a significantly stronger momentum imbalance in heavy-ion collisions than in the p+p reference. When re-examined with correlated soft particles included, we observe that these di-jets then exhibit a unique new feature -- momentum balance is restored to that observed in p+p for a jet resolution parameter of R=0.4, while re-balancing is not attained with a smaller value of R=0.2. 
STAR Collaboration: L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M.   Aggarwal, Z. Ahammed, I. Alekseev, D. M. Anderson, R. ...
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