Charged-particle multiplicity distributions over a wide pseudorapidity range in proton-proton collisions at $\mathbf{\sqrt{s}=}$ 0.9, 7 and 8 TeV

TL;DR

This paper reports on charged-particle multiplicity distributions over a wide pseudorapidity range in proton-proton collisions at three different energies, comparing experimental data with various theoretical models and simulations.

Contribution

It extends the pseudorapidity coverage and high-multiplicity reach of previous measurements using ALICE detectors at the LHC.

Findings

Distributions are measured over $-3.4<ta<5.0$ for =0.9, 7, and 8 TeV.

Results are compared with CMS data and multiple event generators.

The measurements provide new constraints for theoretical models.

Abstract

We present the charged-particle multiplicity distributions over a wide pseudorapidity range ($-3.4<\eta<5.0$) for pp collisions at $\sqrt{s}=$ 0.9, 7, and 8 TeV at the LHC. Results are based on information from the Silicon Pixel Detector and the Forward Multiplicity Detector of ALICE, extending the pseudorapidity coverage of the earlier publications and the high-multiplicity reach. The measurements are compared to results from the CMS experiment and to PYTHIA, PHOJET and EPOS LHC event generators, as well as IP-Glasma calculations.