Proposal to Search for a Dark Photon in Positron on Target Collisions at DAΦNE Linac

Photon-like particles are predicted in many extensions of the Standard Model. They have interactions similar to the photon, are vector bosons, and can be produced together with photons. The present paper proposes a search for such particles in the e(+)e(-) -> U gamma process in a positron-on-target experiment, exploiting the positron beam of the DA Phi NE linac at the Laboratori Nazionali di Frascati, INFN. In one year of running a sensitivity in the relative interaction strength down to similar to 10(-6) is achievable, in the mass region from 2.5 MeV < M-U < 20 MeV. The proposed experimental setup and the analysis technique are discussed.