Recent B-physics results have sparkled great interest in the search for
beyond-the-Standard-Model (BSM) physics in b→cℓνˉ transitions.
The need to analyse in a consistent manner big datasets for these searches,
using high-statistics Monte-Carlo (MC) samples, led to the development of
HAMMER, a software tool which enables to perform a fast morphing of MC-derived
templates to include BSM effects and/or alternative parameterisations of
long-distance effects, avoiding the need to re-generate simulated samples. This
note describes the development of RooHammerModel, an interface between this
tool and the commonly-used data-fitting framework HistFactory. The code is
written in C++ and admits an alternative usage in standalone RooFit analyses.
In this document, the structure and functionality of the user interface are
explained. Information of a public repository where it can be accessed is
provided, as well as validation and performance studies of the interface. The
methods developed in the construction of RooHammerModel can provide specific
information for alternative future attempts to interface HAMMER with other
data-fitting frameworks