Searching for B_c mesons in the ATLAS experiment at LHC

We discuss the feasibility of the observation of the signal from $B_c$ mesons in the ATLAS experiment of the LHC collider at a luminosity of ${\approx}\ 10^{33}$cm$^{-2}$s$^{-1}$. In particular we address the decay mode $B_c{\rightarrow}J/\psi \pi$ followed by the leptonic decay $J/\psi{\rightarrow}\mu^+\mu^-$, which should permit an accurate measurement of the $B_c$ mass. We performed a Monte Carlo study of the signal and background concluding that a precision of $40$ MeV for the $B_c$ mass could be achieved after one year of running.