Measurement of Particle Production and Inclusive Differential Cross Sections in pbar{p} Collisions at sqrt{s}=1.96 TeV

TL;DR

This paper presents detailed measurements of particle production and cross sections in proton-antiproton collisions at 1.96 TeV, revealing discrepancies with existing models and highlighting the need for more sophisticated particle interaction mechanisms.

Contribution

It provides the first measurements of the event transverse energy sum differential cross section and improves the precision of the charged particle transverse momentum spectrum over a wider range.

Findings

High particle momenta are incompatible with previous models.

Monte Carlo generators poorly reproduce the transverse energy sum.

Charged particle transverse momentum depends on event multiplicity, requiring advanced models.

Abstract

We report a set of measurements of particle production in inelastic pbar{p} collisions collected with a minimum-bias trigger at the Tevatron Collider with the CDF II experiment. The inclusive charged particle transverse momentum differential cross section is measured, with improved precision, over a range about ten times wider than in previous measurements. The former modeling of the spectrum appears to be incompatible with the high particle momenta observed. The dependence of the charged particle transverse momentum on the event particle multiplicity is analyzed to study the various components of hadron interactions. This is one of the observable variables most poorly reproduced by the available Monte Carlo generators. A first measurement of the event transverse energy sum differential cross section is also reported. A comparison with a Pythia prediction at the hadron level is performed. The inclusive charged particle differential production cross section is fairly well reproduced only in the transverse momentum range available from previous measurements. At higher momentum the agreement is poor. The transverse energy sum is poorly reproduced over the whole spectrum. The dependence of the charged particle transverse momentum on the particle multiplicity needs the introduction of more sophisticated particle production mechanisms, such as multiple parton interactions, in order to be better explained.