W. T. Giele
D. A. Kosower
A. J. Larkoski
J. J. Lopez-Villarejo
VINCIA is supported by:
The VINCIA code is a plugin to the high-energy physics
event generator PYTHIA 8.2.
Starting from PYTHIA 8.3, VINCIA will be distributed as part of the PYTHIA source code, and hence this standalone plugin will not be relevant to PYTHIA 8.3 users.
VINCIA is based on the dipole-antenna picture of Quantum Chromodynamics
(QCD) and focusses on
describing jets and jet substructure with high precision.
The current version includes both initial- and final-state
QCD and QED showers.
In previous versions of VINCIA, LO matrix elements could be incorporated in the
evolution, as process-dependent 2→n antenna functions. This functionality was removed in the 2.3 series as part of an ongoing effort to move from a matrix-element interface based on MadGraph 4 to one based on MadGraph 5. At the same time, VINCIA is in the process of being merged into the PYTHIA code, where it will be available starting from PYTHIA 8.3. Future development of VINCIA (such as ME corrections based on MG5) will then take place as part of the PYTHIA development.
The remaining perturbative uncertainties are estimated by systematic (and automated)
variations of scales, shower functions, evolution variables, etc.
In the automated mode, a vector
of output weights is produced for each event, the central value of
which is unity (for an ordinary unweighted event sample),
with the uncertainty variations
spreading out around it. The calculation is significantly faster than generating N
separate samples, and there is only one event sample to analyse, pass through detector
When activated, VINCIA replaces the internal PYTHIA parton
is performed with the usual Lund string fragmentation
model, with VINCIA-specific default parameters.
Instead of the PYTHIA initialisation step in the main program
the same function is called on the VINCIA object.
Apart from that, the events are generated and analysed as in a normal
PYTHIA 8 run.
In addition, runtime displays with plots updated in realtime can be
created using the LiveDisplays
The following simple steps set up a standalone VINCIA installation from scratch, complete with linking to PYTHIA 8 and ready-to-run example programs (assuming you have working C++ and F77 compilers which are mutually compatible):
Antenna Showers with One-Loop Matrix Elements. Original reference for (multileg) NLO matching with VINCIA.
Incorporating the NLO correction to ee → 3 jets in the evolution from ee → 2 jets. Studies of dependence on evolution and renormalization scale choices. NLO-corrected tune to ee event-shape, jet-rate, and fragmentation data.
Helicity-Dependent Showers and Matching with VINCIA.
First paper on helicity-dependence in VINCIA. Using individual helicity amplitudes (squared) to drive the matrix-element corrections improves the speed of the matching algorithm. Comparisons to VINCIA without helicity dependence and to CKKW-based SHERPA.
Higher-order Corrections to Timelike Jets.
Original reference for unitarity-based "GKS" matching (iterated matrix-element corrections), smooth ordering, and automated uncertainty bands by Sudakov reweighting. Comparisons to LEP for massless quarks.