CHARYBDIS2

Welcome to the CHARYBDIS2 project page

Overview

CHARYBDIS2 is the new version of the black hole event generator created in:

C.M. Harris, P. Richardson and B.R. Webber, CHARYBDIS: A Black Hole Event Generator, JHEP 0308:033, hep-ph/0307305, 2003.

This code simulates the production and decay of semi-classical microscopic black holes in proton-proton collisions in models with flat extra dimensions and TeV-scale gravity. The black holes are assumed to be produced well above the fundamental planck scale of the model so that the production is classically dominated. (i.e. the cross section is given by geometrical considerations). The decay is assumed to be dominated by Hawking radiation. For more details on the physical assumptions please refer to the papers in the References section and for details on the implementation please consult the Manual.

For step by step instructions on how to download and set up the latest release interfaced to HERWIG and other implementations click here.

Latest release

Version 1.0.2

The latest release is version 1.0.2 (see the Downloads section). This includes some bug fixes and minor upgrades:

A new option to use a charybdis2.init file to input the parameters for the run was added. Also the les houches event .xml files and histories files now contain the full input information in the header which can be placed in a charybdis2.init file to reproduce the run (see detailed description in the charybdis2.init example file provided with the distribution) ;
For the standalone implementation, a bug was fixed which was generating weigthted events and setting the weights to 1 in the les houches file inconsistently. The fixed version now simply generates unweighted events just as the other two HERWIG and PYTHIA implementations were already doing. IMPORTANT: previous versions of the standalone CHARYBDIS implementation will provide inconsistent les houches files so this upgrade is compulsory!

Version 1.0.1

In this release several improvements in the model with respect to previous versions of CHARYBDIS1 were introduced.The most important ones are (refer to the manual for further details) :

A model for the gravitational radiation on the brane lost during formation;
A model for loss of energy and angular momentum during formation;
Modelling of the effects of rotation by introducing the Hawking spectrum of all Standard model fields for a (projected on the brane) Myers-Perry black hole. This includes:

Energy spectrum from the greybody factors;
Angular distributions through the inclusion of spheroidal wave functions.

Several new models for the Planck scale remnant decay:

A boiling model where the evaporation continues with a fixed Hawking temperature until a user defined remnant mass is reached;
N-Body final decay, with a new option to use a product of Hawking spectra (one for each particle) as matrix element;
Stable remnant options.

Previous versions

For CHARYBDIS1 please see this webpage.