  We show how angular distributions can distinguish different scenarios beyond
the standard model by characterising particles of different spins at the LHC.
We illustrate the idea with scalar and vector leptoquarks along with the heavy
fermions in Type-III seesaw as spin zero, spin one and spin half examples
respectively. On the other hand, zeros of single photon tree level amplitude
can separate different particles according their electromagnetic charges. This
phenomenon can be used to distinguish leptoquarks of different gauge
representations, even different excitations of same $SU(2)_L$ gauge group,
within the same spin frame work. We explore electron-photon and electron-hadron
colliders to discern such scenarios in the context of the leptoquark models by
means of zeros in scattering amplitudes. We found that the discerning effect in
these two colliders are complementary to each other and both of them are
required for an exhaustive analysis of leptoquark models. The analyses are
carried out for different leptoquark masses and centre of mass energies of the
collisions which involve a PYTHIA based simulation.
