  It is well known that finding and measuring the masses of particles in the
Minimal Supersymmetric Standard Model (MSSM) at the Large Hadron Collider (LHC)
may be possible using invariant mass distributions in exclusive channels
containing n_j jets and n_l leptons. We perform this analysis for the (n_j,
n_l) = (0,4) decay of heavy Higgs bosons to neutralinos, pp \to H/A \to \chi_i
\chi_j (i,j =2,3,4), which then decay to four leptons and two lightest
neutralinos \chi_1 via on-shell sleptons. When i=j and the sleptons are
degenerate, our Monte Carlo study shows that the LHC will be able to measure
the Higgs and relevant neutralino and slepton masses to roughly
  30%; however, if one of these is already known within 5%, the other three may
be found to equal or better accuracy. This would provide the first accurate
measurement of the H/A mass via invariant mass distribution techniques.
