  We study the possibility of utilising the constrained mass variable,
$M_{2Cons}$, in reconstructing the semi-invisible events originated from a
resonant production at the LHC. While this proposal is effective for any
similar antler type production mechanism, here we demonstrate with potentially
interesting scenario, when the Higgs boson decays into a pair of third
generation $\tau$ leptons. Buoyed with a relatively large Yukawa coupling, the
LHC has already started exploring this pair production to investigate the
properties of Higgs in the leptonic sector. Dominant signatures through
hadronic decay of tau, associated with invisible neutrinos compound the
difficulty in the reconstruction of such events. Exploiting the already
existing Higgs mass bound, this new method provides a unique event
reconstruction, together with a significant enhancement in terms of efficiency
over the existing methods.
