Measurements of Hadron Production at CMS

TL;DR

This paper reports measurements of hadron production in proton-proton collisions at various energies using CMS, highlighting discrepancies with theoretical models in charged hadron and strange particle production rates.

Contribution

First detailed measurements of hadron production at multiple energies with CMS, revealing significant deviations from existing theoretical predictions.

Findings

Charged hadron production rates increase with energy but are underestimated by models.

Strange particle yields exceed Monte Carlo predictions by up to a factor of three.

Transverse momentum and pseudorapidity distributions provide new insights into hadronization processes.

Abstract

Measurements of hadron production in pp collisions at sqrt(s) = 0.9, 2.36 and 7 TeV recorded with the CMS detector are reported. Transverse momentum, pseudorapidity and multiplicity distributions of charged hadrons are presented. For non-single-diffractive collisions, the average charged-hadron transverse momentum and pseudorapidity density reveal an increase in production rate not well matched by theory and models. Measured spectra of identified strange particles, K0S, Lambda, anti-Lambda, Xi- and Xi+, reconstructed based on their decay topology, are also presented. The production rates for strange particles are observed to be in excess of those predicted by Monte Carlo models by up to a factor of three.