  Positron beams, both polarized and unpolarized, are identified as essential
ingredients for the experimental program at the next generation of lepton
accelerators. In the context of the Hadronic Physics program at the Jefferson
Laboratory (JLab), positron beams are complementary, even essential, tools for
a precise understanding of the electromagnetic structure of the nucleon, in
both the elastic and the deep-inelastic regimes. For instance, elastic
scattering of (un)polarized electrons and positrons off the nucleon allows for
a model independent determination of the electromagnetic form factors of the
nucleon. Also, the deeply virtual Compton scattering of (un)polarized electrons
and positrons allows us to separate unambiguously the different contributions
to the cross section of the lepto-production of photons, enabling an accurate
determination of the nucleon Generalized Parton Distributions (GPDs), and
providing an access to its Gravitational Form Factors. Furthermore, positron
beams offer the possibility of alternative tests of the Standard Model through
the search of a dark photon or the precise measurement of electroweak
couplings. This letter proposes to develop an experimental positron program at
JLab to perform unique high impact measurements with respect to the two-photon
exchange problem, the determination of the proton and the neutron GPDs, and the
search for the $A^{\prime}$ dark photon.
