Energy independent scaling of ridge and final state description of high multiplicity p+p collisions at $\sqrt{s}$ = 7 and 13 TeV

TL;DR

This paper investigates whether energy-independent scaling of ridge yields in high multiplicity p+p collisions is consistent with hydrodynamical models, contrasting initial state and final state interaction explanations.

Contribution

It demonstrates that hydrodynamical modeling with EPOS 3 violates the observed energy scaling, suggesting different underlying mechanisms for azimuthal correlations.

Findings

Hydrodynamical models do not reproduce the energy scaling of ridge yields.

Initial state models based on gluon saturation explain the scaling.

Hydrodynamics shows a violation of the observed scaling in high multiplicity p+p collisions.

Abstract

An energy independent scaling of the near-side ridge yield at a given multiplicity has been observed by the ATLAS and the CMS collaborations in p+p collisions at s = 7 and 13 TeV. Such a striking feature of the data can be successfully explained by approaches based on initial state momentum space correlation generated due to gluon saturation. In this paper, we try to examine if such a scaling is also an inherent feature of the approaches that employ strong final state interaction in p+p collisions. We find that hydrodynamical modeling of p+p collisions using EPOS 3 shows a violation of such scaling. The current study can, therefore, provide important new insights on the origin of long range azimuthal correlations in high multiplicity p+p collisions at the LHC energies.