Momentum-Kick Model Application to High-Multiplicity pp Collisions at $\sqrt {s}=13$ TeV at the LHC

Abstract

In this study, the momentum-kick model is used to understand the ridge behaviours in dihadron ∆η-∆ϕ correlations recently reported by the LHC in high-multiplicity proton-proton (pp) collisions.The kick stand model is based on a momentum kick by leading jets to partons in the medium close to the leading jets. The medium where partons move freely is assumed in the model regardless of collision systems. This helps us apply the method to small systems like pp collisions in a simple way. Also, the momentum transfer is purely kinematic and this provides us a strong way to approach the ridge behaviour analytically. There are already several results with this approach in highenergy heavy-ion collisions from the STAR and PHENIX at RHIC and from the CMS at LHC. The momentum-kick model is extended to the recent ridge results in high-multiplicity pp collisions with the ATLAS and CMS at LHC. The medium property in high-multiplicity pp collisions is diagnosed with the result of the model.