Search For the Origin of the Away-side Double-humped Structure of jets in Heavy Ion Collisions

A model is constructed for the origin of the double-humped structure found in the di-hahron azimuthal correlation on the away-side in heavy ion collisions. The parameters in the model are determined by fitting $\Delta\phi$ azimuthal distribution in central Au+Au collisions at RHIC given by STAR collaboration when the trigger momentum is in $3-4\rm {GeV/c}$ and the associated particle momentum is in $1.3-1.8\rm{GeV/c}$. Then we apply our model to the semi-central and peripheral Au+Au collisions at RHIC and the responding $\triangle \phi$ azimuthal distribution are reproduced respectively. Our results show that the transverse flow effect plays an essential role in the experimentally observed di-hadron azimuthal distribution structure. The spread of the hard parton creation point and initial moving direction is also necessary for the double-humped structure.