Heavy Charged Higgs Signals at the LHC

We discuss the viability of $gb \to tH \to ttb$ charged-Higgs signals at the proposed LHC $pp$ supercollider, in the decay channel $tt \to (bq \bar q')(b \ell \nu)$. Here one top quark decays hadronically and one semileptonically, with all three $b$-quarks giving flavor-tagged jets. The principal backgrounds come from $ttg,ttq,ttc$ and $ttb$ continuum production, with possible mis-tagging of $g,q$ and $c$. We conclude that significant signals can be separated from these backgrounds, for limited but interesting ranges of the parameters $m_{H\pm}$ and $\tan\beta$, with the LHC energy and luminosity.