Elliptic flow in proton-proton collisions at 7 TeV

TL;DR

This paper analyzes angular correlations in 7 TeV proton-proton collisions, estimating the elliptic flow component and showing that no extra ridge-like correlations are necessary to explain the data.

Contribution

It introduces a method to decompose angular correlations into flow and non-flow contributions, providing an estimate of elliptic flow in proton-proton collisions at LHC energies.

Findings

Elliptic flow coefficient estimated as 0.04-0.08

Back-to-back emission and momentum conservation explain most correlations

No additional ridge-like correlations are required

Abstract

The angular correlations measured in proton-proton collisions at 7 TeV are decomposed into contributions from back to back emission and elliptic flow. Modeling the dominant term in the correlation functions as a momentum conservation effect or as an effect of the initial transverse velocity of the source, the remaining elliptic flow component can be estimated. The elliptic flow coefficient extracted from the CMS Collaboration data is 0.04-0.08. No additional small-angle, ridge-like correlations are needed to explain the experimental data.