Parton Cascades, Small x, and Saturation in High Energy Collisions ∗ (original) (raw)
Related papers
A parton-hadron cascade approach in high-energy nuclear collisions
Nuclear Physics A, 1998
A parton-hadron cascade model which is the extension of hadronic cascade model incorporating hard partonic scattering based on HIJING is presented to describe the spacetime evolution of parton/hadron system produced by ultra-relativistic nuclear collisions. Hadron yield, baryon stopping and transverse momentum distribution are calculated and compared with HIJING and VNI.
VNI-4.1: Simulation of space-time evolution of e^+e^- .... A+B collisions with parton-cascades, pa
1998
VNI is a general-purpose Monte-Carlo event-generator, which includes the simulation of lepton-lepton, lepton-hadron, lepton-nucleus, hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions. It uses the real-time evolution of parton cascades in conjunction with a self-consistent hadronization scheme, as well as the development of hadron cascades after hadronization. The causal evolution from a specific initial state (determined by the colliding beam particles) is followed by the time-development of the phase-space densities of partons, pre-hadronic parton clusters, and final-state hadrons, in position-space, momentum-space and color-space. The parton-evolution is described in terms of a space-time generalization of the familiar momentum-space description of multiple (semi)hard interactions in QCD, involving 2 -> 2 parton collisions, 2 -> 1 parton fusion processes, and 1 -> 2 radiation processes. The formation of color-singlet pre-hadronic clusters and their decays into...
RHIC Physics with the Parton Cascade Model
Acta Physica Hungarica A) Heavy Ion Physics, 2005
We present an analysis of the net-baryon number rapidity distribution and of direct photon emission in the framework of the Parton Cascade Model.
A New Qualitative Prediction of the Parton Model for High-Energy Hadron Collisions
Foundations of Physics, 2000
Inclusive single jet production in hadron collisions is considered. It is shown that the QCD parton model predicts a nonmonotonic dependence of the inclusive cross section on the fraction of the energy deposited in the jet registered, if it is normalized on the same cross section measured at another collision energy. Specifically, if the cross section is normalized by the one measured at a higher collision energy, it possesses a minimum which depends on jet rapidity. This prediction can be tested at the Fermilab Tevatron, at the CERN LHC, and at the Very Large Hadron Collider under discussion.
Computer Physics Communications, 1994
Based on QCD-inspired models for multiple jets production, we developed a Monte Carlo program to study jet and the associated particle production in high energy pp, pA and AA collisions. The physics behind the program which includes multiple minijet production, soft excitation, nuclear shadowing of parton distribution functions and jet interaction in dense matter is briefly discussed. A detailed description of the program and instructions on how to use it are given.
Photon Production in the Parton Cascade Model
Nuclear Physics A, 2007
We calculate the production of high energy photons from Compton and annihilation processes as well as fragmentation off quarks in the Parton Cascade Model. The multiple scattering of partons is seen to lead to substantial production of high energy photons, which rises further when parton multiplication due to final state radiation is included.
1998
V N I is a general-purpose Monte-Carlo event-generator, which includes the simulation of lepton-lepton, lepton-hadron, lepton-nucleus, hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions. It uses the real-time evolution of parton cascades in conjunction with a self-consistent hadronization scheme, as well as the development of hadron cascades after hadronization. The causal evolution from a specific initial state (determined by the colliding beam particles) is followed by the time-development of the phase-space densities of partons, pre-hadronic parton clusters, and final-state hadrons, in position-space, momentum-space and color-space. The parton-evolution is described in terms of a space-time generalization of the familiar momentum-space description of multiple (semi)hard interactions in QCD, involving 2 → 2 parton collisions, 2 → 1 parton fusion processes, and 1 → 2 radiation processes. The formation of color-singlet pre-hadronic clusters and their decays into hadrons, on the other hand, is treated by using a spatial criterion motivated by confinement and a non-perturbative model for hadronization. Finally, the cascading of produced prehadronic clusters and of hadrons is includes a multitude of 2 → n processes, and is modeled in paralell to the parton cascade description. This paper gives a brief review of the physics underlying V N I, as well as a detailed description of the program itself. The latter program description emphasizes easy-to-use pragmatism and explains how to use the program (including simple examples), annotates input and control parameters, and discusses output data provided by it.
Nuclear Physics A Dynamics of strongly interacting parton-hadron matter
2016
In this study we investigate the dynamics of strongly interacting parton-hadron matter by calculating the centrality dependence of direct photons produced in Au+Au collisions at √ s NN = 200 GeV within the Parton-Hadron-String Dynamics (PHSD) transport approach. As sources for 'direct' photons, we incorporate the interactions of quarks and gluons as well as hadronic interactions (π+ π → ρ+ γ, ρ+ π → π+ γ, meson-meson bremsstrahlung m+ m → m+ m+ γ, meson-baryon bremsstrahlung m+ B → m+ B+ γ), the decays of φ and a 1 mesons and the photons produced in the initial hard collisions ('pQCD'). Our calculations suggest that the channel decomposition of the observed spectrum changes with centrality with an increasing (dominant) contribution of hadronic sources for more peripheral reactions. Furthermore, the 'thermal' photon yield is found to scale roughly with the number of participant nucleons as N α part with α ≈ 1.5, whereas the partonic contribution scales with an exponent α p ≈ 1.75. Additionally, we provide predictions for the centrality dependence of the direct photon elliptic flow v 2 (p T). The direct photon v 2 is seen to be larger in peripheral collisions compared to the most central ones since the photons from the hot deconfined matter in the early stages of the collision carry a much smaller elliptic flow than those from the final hadronic interactions.
Bottom Production in pppppp Collisions at Large Hadron Collider Energies using Parton Cascade Model
arXiv: Nuclear Theory, 2018
We study the production of bottom quarks in pppppp collisions at Large Hadron Collider energies using previously developed parton cascade model to explore the impact of Landau Pomeranchuk Midgal (LPM) effect on their dynamics. In contrast to the case for charm quarks reported recently, we find only a marginal impact of the suppression of multiple scatterings of partons due to the LPM effect on their production. It is felt that this happens as they are only produced in very hard collisions.