Possible Light U(1) Gauge Boson Coupled to Baryon Number

We discuss the phenomenology of a light U(1) gauge boson, γB, that couples only to baryon number. We assume that the new U(1) gauge symmetry is spontaneously broken and that the γB mass mB is smaller than mZ. We show for m_Υ<mB<mZ that the γB coupling αB can be as large as ~0.1 without conflicting with the current experimental constraints. We argue that αB~0.1 is large enough to produce visible collider signatures and that evidence for the γB could be hidden in existing LEP data. We point out that γB exchange can account for rapidity gap events in p-p̄ scattering seen at the Tevatron.