Hunting a Light U(1)_B Gauge Boson Coupled to Baryon Number in Collider Experiments

Abstract

We analyze several signals at HERA and the Tevatron of a light $U(1{)}_B$ gauge boson (${\gamma }_B$) coupling to baryon number. We show that the study of the production of $b\bar{b}$ pairs at the (upgraded) Tevatron can exclude ${\gamma }_B$ with masses ($m_B$) in the range $40\lesssim m_B\lesssim 300$ GeV for ${\gamma }_B$ couplings (${\alpha }_B$) greater than $2\times 10^{-2}$ ($3\times 10^{-3}$). We also show that the HERA experiments cannot improve the present bounds on ${\gamma }_B$. Moreover, we demonstrate that the production at HERA and the Tevatron of di--jet events with large rapidity gaps between the jets cannot be explained by the existence of a light ${\gamma }_B$.

Comments: 5 pages, 5 figures, REVTeX