Exotic Decays of Heavy B quarks

TL;DR

This paper explores exotic decay modes of heavy B quarks involving a new gauge boson $Z'$, proposing search strategies at the LHC that could discover such particles up to 2 TeV, with implications for dark matter and gamma-ray excesses.

Contribution

The paper introduces a novel decay channel for B quarks involving a $Z'$ boson and develops search strategies for LHC detection, extending the mass reach beyond previous searches.

Findings

LHC can potentially discover B quarks below 1.6 TeV with 300 fb$^{-1}$.

High-luminosity runs could extend discovery reach to 2 TeV.

Models can explain gamma-ray excesses via dark matter interactions.

Abstract

Heavy vector-like quarks of charge $-1/3$, $B$, have been searched for at the LHC through the decays $B\rightarrow bZ,\, bh,\,tW$. 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 $B\rightarrow bZ^\prime\rightarrow b (b\bar{b})$. 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 $Z'$ for $B$ quarks with mass below $\sim 1.6$ TeV, for a broad range of $Z'$ masses. A high-luminosity run can extend this reach to $2$ TeV.