Predictions of Quark-Gluon String Model for pp at LHC

TL;DR

The paper addresses soft hadron-hadron collisions using the nonperturbative Quark-Gluon Strings Model (QGSM), which combines Regge theory and a 1/N expansion to describe multiparticle production via cut-Pomeron showers and string fragmentation. It derives inclusive spectra through convolutions of proton structure and fragmentation functions for 2$n$ strings, with parameters anchored to $pp$ and $p\bar{p}$ data and without free parameters in the comparison to data. The authors validate QGSM against S$p\bar{p}$S and Tevatron measurements of pseudorapidity and multiplicity, and provide predictions for LHC energies, including central and forward pseudorapidity regions; they note the asymptotic behavior $(dN/dy)_{y=0} \propto s^{\Delta}/\ln^2 s$ and $\langle N_{ch} \rangle \propto s^{\Delta}/\ln s$, while acknowledging the neglect of enhanced diagrams. The work delivers a parameter-free baseline for soft QCD extrapolations to the LHC and outlines future MC developments to incorporate pomeron interactions.

Abstract

Soft multiparticle production processes in hadronic collisions are considered in the framework of the Quark-Gluon Strings Model and the model predictions are compared with data from SppS and Tevatron. Predictions for LHC energies are given.

Figures (6)

• Figure 1: Comparison of phenomenologically expected dependence of mean transfers momentum of secondary particles on charged particles multiplicity with experimental data from CDF ref16.
• Figure 2: Comparison of model's prediction with data on charged particles pseudorapidity distribution in NSD events and prediction for LHC: a) description of UA5 data ref17, b) description of CDF and P238 data (circles and squares, respectively) ref18.
• Figure 3: Energy dependence of charged particles pseudorapidity density at $\eta =0$ for NSD events. Data are taken from ref17ref18ref19.
• Figure 4: Comparison of model predictions with UA5 data on charged particles multiplicity distribution in NSD events at $\sqrt{s}$ = 900 GeV.
• Figure 5: Predictions for charged particles multiplicity distributions at LHC.