Speaker
Description
The statistical model is an extremely information-dense and
comprehensive representation of a physics measurement, which is
why efforts to preserve and publish it have been pursued for
years. One of the main challenges is to find a format in which to
store a statistical model that is useful for people external to
the experimental community and not bound to a specific
software (such as RooFit or RooFit-derived customized pdf
classes), while at the same time being general enough to cover
all use-cases. With the advent of pyhf and its JSON
specification for statistical models, the community has seen a
surge in publishing full models, which has been well-received by
theorists. While the reduced use case of HistFactory lends itself
to a compact and declarative representation, the extension of
such a format for a general, open-world scenario is challenging,
but of critical importance. The RooJSONFactoryWSTool is a new
addition to RooFit that allows the export and import of generic
workspaces to JSON or YAML. The path chosen to address the
challenge is to provide a fully extensible interface to register
new types of functions and pdfs, allowing to import and export
not only classes shipped with ROOT, but any implementation
residing in a workspace. The accompanying documentation sets out
a draft for a "High Energy Physics Statistics Serialization
Standard" (HS3), which will hopefully be adopted and extended by
the community and increase traction for the publishing of
statistical models. The implementation is still in experimental
stage, but available with ROOT 6.26/00.