VNI version 4.1. Simulation of high-energy particle collisions in QCD: Space-time evolution of e{sup +}e{sup {minus}}...A + B collisions with parton-cascades, cluster-hadronization, final-state hadron cascades

Technical Report · Mon Feb 01 04:00:00 EST 1999

DOI:https://doi.org/10.2172/314115· OSTI ID:314115

Geiger, K; Longacre, R ^[1]; Srivastava, D K ^[2]

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1. Brookhaven National Lab., Upton, NY (United States). Physics Dept.
2. Variable Energy Cyclotron Centre, Calcutta (India)

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 {r_arrow} 2 parton collisions, 2 {r_arrow} 1 parton fusion processes, and 1 {r_arrow} 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 includes a multitude of 2 {r_arrow} n processes, and is modeled in parallel to the parton cascade description. This paper gives a brief review of the physics underlying VNI, 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.

• Research Organization: Brookhaven National Lab., Physics Dept., Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 314115
• Report Number(s): BNL--65755; ON: DE99001688; BR: KB0300000
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
99 GENERAL AND MISCELLANEOUS
COMPUTER PROGRAM DOCUMENTATION
FINAL-STATE INTERACTIONS
MONTE CARLO METHOD
PARTICLE INTERACTIONS
PARTICLE KINEMATICS
PARTON MODEL
QUANTUM CHROMODYNAMICS
V CODES