as noted in section III, all detector effects can be casted in the form of a signal acceptance , including also the effect of kinematic and angular acceptance cuts. By looking at Refs. [4, 5, 29], we estimate an overall acceptance factor of ∼ 70%, which we found to be approximately constant over the mass regions considered, to be applied to our parton level results [once the cuts of eqs. (10) and (15) are considered]. This acceptance is mainly related to the leptons identification, both at the Tevatron and at the LHC. On the significance, as in eq. (19), the reduction is then of ∼ 84%. A general feature is that greater sensitivity to the Z ′ B − L resonance is provided by the electron channel. At the LHC this has better energy resolution than the muon channel. A further consequence of the better resolution of electrons is that an estimate of the gauge boson width would eventually be possible for smaller values of the Z ′ B − L boson mass than in the muon channel. Limits from existing data imply that the first couplings that will start to be probed at the LHC are those around g ′ 1 = 0 . 1. Increased luminosity will enable both larger and smaller couplings to be probed. Our comparison showed that, for integrated luminosity of 10 fb − $^{1}$, the Tevatron is still competitive with the LHC in the electron channel and in the small mass region, being able to probe the coupling at the level of 5 σ down to a value of 4 . 2 · 10 − $^{2}$. The LHC will start to be competitive in such a region only for integrated luminosities close to 1 fb − 1 at √$_{s}$ = 7 TeV, or equivalently 500 pb − 1 at √$_{s}$ = 10 TeV (comparing the luminosities required for a 5 σ discovery of Z ′ B − L boson of 600 GeV mass for g ′ 1 = 0 . 05). Also, at √$_{s}$ = 7 TeV the mass reach will be extended from the Tevatron value of M$_{Z}$ ′ = 850 GeV, with electrons, up to 1 . 25(1 . 20) TeV for electrons(muons). The muon channel at Tevatron needs more than 10 fb − 1 to start probing the Z ′ B − L at 3 σ . Hence, it has not been studied. The LHC at √$_{s}$ = 10 TeV will be able to further extend the kinematic reach of the Z ′ B − L boson, being able to probe it for masses much bigger than those available at the Tevatron, up to M$_{Z}$ ′ = 1 . 8(1 . 7) TeV with ∫ L = 1 fb − 1 of data, depending on whether one is looking at electrons(muons). When the data from the high energy runs at the LHC become available, the discovery reach of Z ′ B − L boson will be extended towards very high masses and small couplings in regions of parameter space well beyond the reach of the Tevatron and comparable in scope with those accessible at a future LC [17]. If no evidence is found at any energies, 95% C.L. limits can be derived, and, given their 30