Table of Contents
- The GiBUU project
- GiBUU model
- Getting the GiBUU code
- The History of BUU Codes at Giessen
- The GiBUU Team
The GiBUU project
The GiBUU project provides a unified theory and transport framework in the MeV and GeV energy regimes for
- elementary reactions on nuclei, as e.g.
- electron + A,
- photon + A,
- neutrino + A ,
- hadron + A (especially pion + A and proton + A)
- and for A + A heavy-ion collisions,
using the same physics input and code. The GiBUU code provides a full dynamical description of the reaction and delivers the complete final state of an event; it can thus be used as an event generator. The source code is freely available.
For all the reactions, the flow of particles is modeled within a Boltzmann-Uehling-Uhlenbeck (BUU) framework. The relevant degrees of freedom are mesons and baryons, which propagate in mean fields and scatter according to cross sections which are applicable to the energy range of a few 10 MeV to about 40 GeV. In the higher energy regimes the concept of pre-hadronic interactions is implemented in order to realize color transparency and formation time effects. For a general overview of the model, its theoretical basis as well as many practical details, refer to the review paper:
Transport-theoretical Description of Nuclear Reactions
O. Buss, T. Gaitanos, K. Gallmeister, H. van Hees, M. Kaskulov, O. Lalakulich, A. B. Larionov, T. Leitner, J. Weil, U. Mosel
Phys. Rept. 512 (2012) 1-124 / Inspire
The numerical implementation, named GiBUU (aka The Giessen BUU Project), is written in modular Fortran 2003 and based upon a Subversion version control system, which allows for a concise control over the full development phase of the code.
The history of the code is rather long and reports about several main development steps. The present initiative accomplished a total rewrite of the source code in a present-day computing language. The main goals of this effort were modularization to allow for a more transparent multi-user development process, a strict reduction of global variables for a more transparent debugging procedure, an improved control over the development phase such that modifications can be backtracked and a unified standard version. Therefore every member of the team works on the same single code version, albeit different temporal branches may coexist. Possible technical overhead is compensated by the benefit of a faster distribution of improvements and innovations and their enhanced sustainability.
GiBUU is being developed by a collaboration of people at different institutes:
- Institut für Theoretische Physik of the Justus-Liebig-Universität Giessen.
- Institut für Theoretische Physik of the Goethe Universität Frankfurt
- Joint Institute for Nuclear Research, Dubna
- Physics Department, Aristotle University of Thessaloniki
- 8. Feb. 2021: GiBUU 2021 has been released.
- Modifications of rho-spectral function and dilepton production (https://inspirehep.net/literature/1818931)
- improved 2pi background in e+N and nu+N collisions, improved transition from RES to DIS
- Calculation of nuclear residue (cf. https://inspirehep.net/literature/1710338)
- restrict number of ejected nucleons in perturbative runs by residue
- implement in-medium changes of NN cross sections
- Earlier Releases: see Release Notes
The GiBUU Model
- Physics input -- Learn more about our model
- Visualizations, Movies
The GiBUU Team
- Get-it-running: (...for the impatients: the installation in less than 10 lines)
- Release Notes
- Register -- Become a registered GiBUU user
- FAQ -- Frequently asked questions
- Fortran -- Literature, Links, ...
- Automatic Code Documentation (Robodoc):
- GiBUU particle numbering scheme
- Job cards -- Examples for GiBUU input files
- Event Output
- perWeight -- How to obtain cross sections from the event files
- CollisionList -- How to write out all interaction history
- Ein Lasso für die Geisterteilchen, pro-physik, 27. September 2016
- Neutrinos on nuclei (by U. Mosel), CERN Courier, 22. September 2017
- Neutrino Long-Baseline Experiments and Nuclear Physics (by U. Mosel), in: Nuclear Physics News, v52, no 4, Dec. 2019