VINCIA User Reference
March 2011 ©
W. T. Giele,
D. A. Kosower, M. Ritzmann,
P. Z. Skands
The VINCIA code is a plugin to the high-energy physics
event generator
PYTHIA 8.
It is based on the dipole-antenna picture of QCD and focusses on
describing quark and gluon radiation with high precision. It
incorporates a novel scheme for matching to fixed-order matrix
elements and also has extensive possibilities for estimating the
remaining uncertainties by systematic variation of shower
parameters. When activated, it replaces the internal PYTHIA parton
cascades. Hadronization is performed as usual in PYTHIA, with the
Lund string fragmentation model. VINCIA is currently implemented for QCD
final-state showers and includes mass effects for charm and heavier quarks.
|
This documentation contains
brief descriptions of each of the user-specifiable
parameters of the
VINCIA
code, together with instructions how to install, link, and initialize
it. Use the menu to the left to navigate. These files
are purely for documentation and
should not be modified by the user. Instead, see the
section on
Initialization
for how to set and change parameters.
To ensure accurate reproducibility, when quoting VINCIA
results, please state both the exact PYTHIA
and VINCIA versions used, along with any relevant non-default settings (for
both programs). On plots, please
give both PYTHIA and VINCIA versions.
VINCIA is licenced under the GNU GPL version 2.
Please respect the
MCnet Guidelines for Event Generator Authors and Users.
The name VINCIA stands for "Virtual Numerical Collider with
Interleaved Antennae".
Compatibility
Use the following compatibility table to ensure that your VINCIA and
PYTHIA versions are compatible
|
PYTHIA Versions |
VINCIA Versions |
Comments |
|
8.145 |
1.025 |
PYTHIA changed CoupSM to Couplings |
8.135 - 8.140 |
1.024 |
PYTHIA modified inherited TimeShower::prepare() function |
8.135 |
1.019 - 1.023 |
PYTHIA removed static dependencies |
8.100 - 8.130 |
1.000 - 1.018 |
|
|
Types of Parameters
As in PYTHIA 8, there are 4 types of parameters:
flag
: boolean. Several input forms are accepted:
either of
on
/off
,
true
/false
,
yes
/no
, or 1
/0
will do.
mode
: integer
parm
: real number (double precision)
word
: text string
Useful References
A log of update notes and installation instructions is kept in
the README.TXT accompanying the
distribution.
The main VINCIA references are:
- Showers:
A simple shower and matching algorithm, W. Giele, D. Kosower,
P. Skands, PRD78(2008)014026
- Matching:
Higher-order corrections to timelike jets, W. Giele, D. Kosower,
P. Skands, arXiv:1102.2126
The main PYTHIA 8 reference is
- A Brief Introduction to PYTHIA 8.1, T. Sjöstrand,
S. Mrenna and P. Skands,
CPC178(2008)852
The interface to MADGRAPH further relies on
- MadGraph/MadEvent v4: The New Web Generation, J. Alwall et al.,
JHEP09(2007)028
- HELAS: HELicity amplitude subroutines for Feynman diagram
evaluations, H. Murayama et al.,
KEK-91-11
To learn more about the physics of Event Generators, see
- General-purpose event generators for LHC physics, MCnet
Collaboration, arXiv:1101.2599
- PYTHIA 6.4 Physics and Manual. T. Sjöstrand,
S. Mrenna and P. Skands,
JHEP05(2006)026
The default antenna functions used by VINCIA are described in
detail in
- Antenna Subtraction at NNLO, A. Gehrmann-De Ridder, T. Gehrmann, E.W.N. Glover,
JHEP09(2005)056
- Timelike Showers Based on Dipole-Antenna Radiation Functions,
R. Frederix, W. Giele, D. Kosower, P. Skands, in The NLO multileg
working group: Summary report, arXiv:0803.0494 [hep-ph]
- Infrared Structure of e+e- -> 3 jets at NNLO,
A. Gehrmann-De Ridder, T. Gehrmann, E.W.N. Glover, G. Heinrich,
JHEP11(2007)058
- Matching NLLA + NNLO for
event shape distributions, T. Gehrmann, G. Luisoni, H. Stenzel, PLB664(2008)265
The basic use of dipole-antennae as a dual description of QCD in the context
of Shower Monte Carlos goes back to the Lund dipole,
- Dipole Formulation of QCD Cascades, G. Gustafson and
U. Pettersson, NPB306(1988)746
- Dual Description of a Confined Color Field, G. Gustafson,
PLB175(1986)453
To learn more about Les Houches color tags, used both by PYTHIA
and VINCIA to keep track of color connections, see
-
Generic user process interface for event generators, E. Boos et al.,
hep-ph/0109068
-
A Standard format for Les Houches event files, J. Alwall et al.,
CPC176(2007)300
Version
These settings should not be changed by the ordinary user,
but appear here for documentation purposes, and so that they can form
part of the standard databases and be queried accordingly.
parm
Vincia:versionNumber
(default = 1.025
)
Version and subversion number, with three significant decimals.
mode
Vincia:versionDate
(default = 20110318
)
Last date of change of current (sub)version, in format yyyymmdd.
Last modified: