GENIE is an
international collaboration of scientists that
plays the leading role in
a) the development of a modern and universal event generator framework and tools in support of neutrino experiments,
b) the consistent, validated and efficient implementation of a constellation of alternative physics models within a common platform,
c) the development and characterisation of novel
comprehensive physics models for the
simulation
of neutrino interactions, and
d) the development of an advanced
global analysis of neutrino scattering data.
The GENIE collaboration
maintains a popular suite of software products
(including the
Generator,
Comparisons,
Tuning, and
Reweight products)
for the experimental neutrino community.
The well-known
Generator implements a modern framework for Monte Carlo event generators and
includes state-of-the-art physics modules. The
GENIE physics model is universal and comprehensive:
It handles all neutrinos and targets, and all processes relevant from MeV to PeV energy scales.
The
Generator includes several tools (flux drivers, detector geometry navigation drivers,
and specialized event generation apps)
to
simulate complex experimental setups in full detail.
The GENIE
Generator is
used by nearly all modern neutrino experiments and its
predictions serve as standard reference points for the neutrino community.
The
Comparisons product includes very
extensive curated archives of neutrino, charged-lepton
and hadron scattering data, as well as highly-developed software to produce a
comprehensive set of data/MC comparisons.
It includes embedded
interfaces to the Professor tuning tool
which "
reduces the exponentially expensive process of brute-force tuning to a scaling closer to a power
law in the number of parameters and allows for massive parallelisation".
The
Comparisons product plays a key role in comprehensive model characterization in GENIE,
it underpins the GENIE global analysis, and it enabled the production of several new tunes.
The
Tuning product implements
the
powerfull new GENIE global analysis of neutrino scattering data.
The GENIE global analysis produces
physics tunes which are fully integrated in the
Generator product.
Finally, the
Reweight product includes a selection of tools to
propagate model uncertainties
and to support generator-related analysis tasks.
The reweighting procedure has inherent limitations. Important modelling systematics are not reweightable
in principle and they have no corresponding weight calculator in the
Reweight product.
Indeed, the GENIE tuning procedure itself makes no use of the Reweight product but it relies on response
functions constructed from brute-force parameter scans made with the aid of the Professor tool.
Currently, the
Reweight product it does not provide the full systematic error
for any GENIE tune. However, we have
medium-term plans to overhaul this product and use it for
public release of the detailed Professor/YODA response functions constructed from our
brute-force systematic parameter scans, as well as to
release all covariance matrices from the GENIE global fits of neutrino scattering data.
The upgraded
Reweight product will support all public GENIE physics tunes!