  Forward-backward multiplicity correlations have been studied in
electron-positron, proton-proton and more recently in lead-lead collisions. For
the proton-proton case, comparison of experimental results to different models
reveals an incomplete understanding of the physical phenomenon associated with
these correlations. In this work, we present a study of forward-backward
multiplicity correlations in proton-proton collisions using the PYTHIA event
generator, at LHC energies. A detailed analysis is presented with and without
weak decays, splitting data samples into soft and hard QCD processes, and
comparing the computed correlations for short and long range pseudorapidity
regions. Each of these regions is analyzed accounting for the effects of color
reconnection and independent multiple parton interactions. We show that a
combination of these effects is required to explain the latest measurements on
proton-proton data. Furthermore, is shown that from measurements of
multiplicity correlations is possible to extract the average number of multiple
parton interactions in the event producing these correlations, and albeit model
depending, to predict the strength of these correlations, not yet measured, for
higher energy collisions.
