Searching for a U-boson with a positron beam

Abstract

A high sensitivity search for a light \Ub{} by means of a positron beam incident on a hydrogen target is proposed. We described a concept of the experiment and two possible realizations. The projected result of this experiment corresponds to an upper limit on the square of coupling constant $ |f_{_{eU}}|^2 = 3 \times 10^{-9}$ with a signal to noise ratio of five.