  The kinematic constrains on interacting nucleons in Large Hadron Collider
(LHC) heavy-ion collisions are investigated in the framework of the Heavy Ion
Jet Interaction Generator (HIJING) code incorporated with a collective cascade
recipe. The latter is used to implement energy-momentum conservation constrains
on both primary and secondary interacting nucleons. It is found that the
energy-momentum conservation constrains on the interacting nucleons affect the
whole charged particle pseudo-rapidity density distribution
$(\frac{dN_{ch}}{d\eta})$, at different centralities (from central (0-5\%) to
peripheral (70-80\%) collisions), in Pb+Pb collisions at $\sqrt{s_{NN}} =2.76$
TeV. In particular, the kinematic constrains on interacting nucleons are shown
to reduce $(\frac{dN_{ch}}{d\eta})$ yield at mid-pseudorapidity
$(\lvert\eta\rvert<2)$ in all centrality intervals, which is consistent with
the LHC data. In addition, the model predicts an enhancement of the hadron
production at $\lvert\eta\rvert>8$, which could be checked in future ALICE Zero
Degree calorimeter. Such an enhancement is found to be mainly due to the
interactions of protons at the spectator parts of the collision. This indicates
that the kinematic constrains are important for a correct geometrical treatment
of Pb+Pb collisions at LHC energies.
