Exotic Decays of Heavy B quarks

Abstract

Heavy vector-like quarks of charge $-1/3$, $B$, have been searched for at the LHC through the decays $B\to bZ,bh,tW$. In models where the $B$ quark also carries charge under a new gauge group, new decay channels may dominate. We focus on the case where the $B$ is charged under a $U(1{)}^{\prime }$ and describe simple models where the dominant decay mode is $B\to b{Z}^{\prime }\to b(b\bar{b})$. With the inclusion of dark matter such models can explain the excess of gamma rays from the Galactic center. We develop a search strategy for this decay chain and estimate that with integrated luminosity of 300 fb${}^{-1}$ the LHC will have the potential to discover both the $B$ and the $Z^{\prime }$ for $B$ quarks with mass below $\sim 1.6$ TeV, for a broad range of $Z^{\prime }$ masses. A high-luminosity run can extend this reach to $2$ TeV.

Comments: 28 pages, 10 figures, 3 tables