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 (${\hat{I}}_B^3$) coupling to baryon number. We show that the study of the production of $b\bar{b}$ pairs at the (upgraded) Tevatron can exclude ${\hat{I}}_B^3$ with masses ($m_B$) in the range $40\lesssim m_B\lesssim 300$ GeV for ${\hat{I}}_B^3$ couplings ($\hat{I}{\pm }_B$) greater than $2\times 10^{-2}$ ($3\times 10^{-3}$). We also show that the HERA experiments cannot improve the present bounds on ${\hat{I}}_B^3$. 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 ${\hat{I}}_B^3$.

5 pages, 5 figures, REVTeX