The default antenna functions used in VINCIA largely resemble those used by Gehrmann, de-Ridder, and Glover (GGG), with some simplifactions in the structure of the non-singular terms. A few alternative antenna sets are also provided and can be used, e.g., for uncertainty variations. It is also possible for users to define their own sets.
To use an alternative set of antennae (i.e., non-default), a convenient way of specifying a collection of non-default parameters is to use
word
Vincia:antennaFile
(default = none
)Note: this command file will be read in during construction of the VINCIA plug-in. Any desired further modifications of the antenna functions should therefore only be performed after construction of the plug-in.
Some pre-defined antennae shipping with VINCIA are stored in a separate subdirectory calledantennae/
(see below).
More user-defined antennae can be added and stored in the same
directory, if desired. To use them with a program that
runs in your main VINCIA directory (default), include the following
command in your main program or command file:
antennae/
directory, give the full path- and filename instead, as in
Note: the format of the antenna files is the same as that of ordinary PYTHIA 8 command files, hence any combination of VINCIA and PYTHIA 8 commands could in principle be included to define an antenna set, but in general we advise to keep only specific antenna-related parameters in the antenna definition files, to avoid confusions/conflicts between your main command file(s) and the antenna file.
The default antennae have been chosen to be close to the GGG ones
and have been verified to give a good average agreement with Z→n
matrix elements. The following two examples, included with the
VINCIA package in the antennae/
subdirectory, have been defined so as to try to span a
reasonable min-max uncertainty range: