Long- and short-range correlations and their event-scale dependence in high-multiplicity pp collisions at $\sqrt{\text{s}}=13$ TeV

Abstract

Two-particle angular correlations are measured in high-multiplicity proton-proton collisions at $\sqrt{s}=13$ TeV by the ALICE Collaboration. The yields of particle pairs at short-($\Delta \eta$ $\sim$ 0) and long-range ($1.6<|\Delta \eta |<1.8$) in pseudorapidity are extracted on the near-side ($\Delta \phi$ $\sim$ 0). They are reported as a function of transverse momentum ($p_{\mathrm{T}}$) in the range $1<p_{\mathrm{T}}<4$ GeV/$c$. Furthermore, the event-scale dependence is studied for the first time by requiring the presence of high-$p_{\mathrm{T}}$ leading particles and jets for varying $p_{\mathrm{T}}$ thresholds. The results demonstrate that the long-range "ridge" yield, possibly related to the collective behavior of the system, is present in events with high-$p_{\mathrm{T}}$ processes. The magnitudes of the short- and long-range yields are found to grow with the event scale. The results are compared to EPOS LHC and PYTHIA 8 calculations, with and without string-shoving interactions. It is found that while both models describe the qualitative trends in the data, calculations from EPOS LHC show a better quantitative agreement, in particular for the $p_{\mathrm{T}}$ and event-scale dependencies.

24 pages, 7 captioned figures, 1 table, authors from page 19, published version, figures at http://alice-publications.web.cern.ch/node/6759

References in corpus (9)

• Viscosity Information from Relativistic Nuclear Collisions: How Perfect is the Fluid Observed at RHIC?
• Triangular flow in hydrodynamics and transport theory
• Elliptic flow of identified hadrons in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Measurement of jet suppression in central Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Imprints of fluctuating proton shapes on flow in proton-lead collisions at the LHC
• Evidence for BFKL and saturation dynamics from di-hadron spectra at the LHC
• Transverse nucleon structure and diagnostics of hard parton-parton processes at LHC
• Importance of initial and final state effects for azimuthal correlations in p+Pb collisions
• Measurement of the underlying event activity in pp collisions at sqrt(s) = 0.9 and 7 TeV with the novel jet-area/median approach

Cited by in corpus (8)

• The Muon Puzzle in cosmic-ray induced air showers and its connection to the Large Hadron Collider
• Event Generators for High-Energy Physics Experiments
• Emergence of long-range angular correlations in low-multiplicity proton-proton collisions
• System size dependence of the hadronic rescattering effect at energies available at the CERN Large Hadron Collider
• K${}_{\mathrm{S}}^0$- and (anti-)$\Lambda$-hadron correlations in pp collisions at $\sqrt{s}=13$ TeV
• Model study on ${\rm Y}(nS)$ modification in small collision systems
• Measurement of event shapes in minimum-bias events from proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Antiproton production with a fixed target and search for superheavy particles at the LHC