[en] We present a search for a narrow resonance in the t(bar b) mass spectrum using 1.9 fb^-1 of p(bar p) collisions at √s = 1.96 TeV recorded with the CDF II detector at the Fermilab Tevatron. We select events with a lepton, neutrino candidate, and two or three jets from which to construct the t(bar b) mass. We quantify the result using the model of a massive Standard Model-like charged-boson (W(prime)) decaying to t(bar b), but we are generally sensitive to the presence of any narrow state decaying to the third generation. For a purely right-handed W(prime) with Standard Model couplings, we set a new limit at 95% confidence of σ(p(bar p) → W(prime)_R) x BR(W(prime)_R → t(bar b)) < 0.28 pb and M_W#prime#_#sub R# > 800 GeV/c². The limit increases to M_W#prime#_#sub R# > 825 GeV/c² if decay to right-handed neutrinos is forbidden. These results are shown in Table 7 and plotted in Figure 7.1. The best prior search found M_W#prime# (ge) 768 GeV/c² if leptonic decays are forbidden (16). For a simple W(prime) model with effective coupling g_W#prime#, the cross-section is proportional to g_W#prime#⁴. Relaxing the assumption of the universal weak coupling (g_W#prime# = g_W), our cross-section limits can be rewritten as upper limits on g_W#prime#, as a function of M_W#prime#. This is relevant to both the right-handed W(prime) model as well as a left-handed W(prime) model in which the W(prime)_L-W interference is negligible. The excluded region of the g_W#prime#-M_W#prime# plane is shown in Figure 7.2, with g_W#prime# in units of g_W. At M_W#prime# = 300 GeV/c², we limit (95% C.L.) the effective coupling to be less than 0.40 of the standard weak coupling