emela: an improved QED-version of MELA
copied from cf-staging / emelaeMELA is a library that implements the evolution in pure QED of the
unpolarised electron parton distribution functions (PDFs) up to
next-to-leading logarithmic (NLL) approximation, according to the papers
listed on the GitHub repository. eMELA includes the evolution with
multiple fermion families and their mass thresholds, and it gives one the
possibility of choosing among three different UV-renormalisation schemes
(MSBAR: $\overline{\rm MS}$, ALPMZ: $\alpha(mZ)$, ALGMU: $G\mu$)
and two different factorisation schemes
(MSBAR: $\overline{\rm MS}$, DELTA: $\Delta$).
More in detail, eMELA is an improved QED-version of
MELA. It consists of a Fortran code
responsible for the numerical evolution of the PDFs, and a C++ wrapper that
provides one with the analytical solutions in the asymptotic $z \to 1$
region. Moreover, the possibility is given to the user to output the PDFs
as grids compliant with the
LHAPDF format, that can be
employed at a later stage. Regardless of whether the numerical solution is
computed at runtime or read from the grids, eMELA offers the possibility
to switch to the analytical solution in the asymptotic region. This must be
considered as the default option when using the PDFs for physics
simulations.
Note: eMELA supersedes ePDF, that was limited to the evolution with a single lepton in the $\overline{\rm MS}$ renormalisation and factorisation schemes.
