Parton ladder splitting and the rapidity dependence of transverse momentum spectra in deuteron-gold collisions at the BNL Relativistic Heavy Ion Collider

Abstract

We present a phenomenological approach (EPOS), based on the parton model, but going much beyond, and try to understand proton-proton and deuteron-gold collisions, in particular the transverse momentum results from all the four RHIC experiments. It turns out that elastic and inelastic parton ladder splitting is the key issue. Elastic splitting is in fact related to screening and saturation, but much more important is the inelastic contribution, being crucial to understand the data. We investigate in detail the rapidity dependence of nuclear effects, which is actually relatively weak in the model, in perfect agreement with the data, if the latter ones are interpreted correctly.

EPOS LHC: Test of collective hadronization with data measured at the CERN Large Hadron Collider

“…Such an elementary scattering is the so-called "parton ladder," see Fig. 2, also referred to as cut Pomeron [6].…”

“…Such a model exists and has been actively developed for about 20 years. EPOS [6] is based on the parton-based Gribov-Regge theory [7] developed for NEXUS, which was based on the VENUS model [8] for soft interactions and the QGSJET model [9] for the semihard scattering.…”

Proceedings of the 7th International Workshop on Very High Energy Particle Astronomy in 2014 (VHEPA2014)

“…The energy spectrum of photons and the transverse momentum spectra of π 0 s were already published [9,10]. Figure 2 shows the transverse momentum spectrum of π 0 s measured by LHCf (black dots) with predictions of several hadronic interaction models (colored lines) [11][12][13][14][15]. The best agreement with LHCf data is given by EPOS1.99 in the models.…”

“…The black dots and the shaded area show LHCf data and the uncertainties. The color lines indicate the predictions by several hadron interaction models [11][12][13][14][15].…”

Recent Results on Soft QCD at ATLAS

“…The predictions of various QCD-based models are also shown. The best descriptions are provided by the Pythia 6 [4] tune DW and the Epos-LHC tune [5,6]. The Pythia 6 MC09 tune prescribes slightly greater yields than are observed the data.…”