pandora

This page is intended to distribute the current version of a new physics event generator for linear collider studies, called pandora. The link below transmits a tar.gz file containing the C++ code for pandora, and some limited documentation.

The program pandora is intended to be a general-purpose event generator which includes beamstrahlung, initial state radiation, hadronization, and full treatment of polarization effects. This version includes the SM physics processes:

e+e- -> l+l-, q qbar , e+e-, gamma gamma, t tbar, Z gamma, ZZ, W+W-
e+e- -> Z Higgs, nu nubar Higgs, e+e- Higgs, nu nubar gamma
gamma gamma -> l+l-, q qbar, t tbar, e+e-, W+W-, Higgs
e gamma -> e gamma, e Z, nu W
e-e- -> e-e-

and some illustrative Beyond the SM processes:

e+e- -> l+l-, q qbar , e+e-, with a Z' or with Hewett's contact interaction for extra dimensions
e+e- -> gamma Graviton
e+e- -> t tbar, with general production and decay form factors
e+e- -> W+W-, with a technirho resonance

To download pandora, click this link to receive a tar.gz file. This download contains all C++ files needed to run pandora simulations at the parton level.

Some sample programs are contained in the directories SMexamples, SM3examples, BSMexamples. On a UNIX system, it might well be possible to simply enter one of these directories, type (for the program ttevents.C, for example) `make ttevents', and watch the program compile. More often, you will need to do some minor tinkering with the makefile (e.g. change `CC' to `g++' at the top). Programs whose names end in `events' generate a few events and output them to the console. Programs which end in `example' generate a few thousand events and create histograms of their properties as topdraw (.top) graphics files.

Pandora treats e+e- reactions only at the parton level. To include hadronization, you need the `pandora_pythia' interface, written by Masako Iwasaki. That can be obtained by following this link. Instructions for download and running of pandora_pythia are given on that page.

The treatment of initial state radiation and beamstrahlung in pandora is described in my note LCC-0010. You can access that paper from here in ps and pdf versions. The functions described there are encoded in the files ebeams.h and ebeams.C in the package above.

A detailed manual for pandora is now being prepared. Some basic documentation for pandora is contained in the file pandora.README file included in the download. A gentle introduction to pandora is given in this lecture. The documentation directory also includes notes on the polarization conventions used in pandora, the modification of beam and accelerator parameters, and the (still primitive) SUSY processes included.

The current version (6 September 2000) is pandora 2.2. The basic example programs are consistent with earlier versions; however, the internal structures of many of the underlying classes have been modified. (I thank K. Fujii for much useful advice on these issues.) Earlier versions of pandora can be obtained here:

pandora 2.0 (August, 2000).
pandora 2.1 (September, 2000)

Patches for the current (2.2) PANDORA

Please send comments or questions to Michael E. Peskin.

SLAC