Effects of lepton number violating interactions on $t\bar{t}$ production at NLC

We discuss the effects of lepton number violating interactions namely, R-parity violation and leptoquarks on top quark pair production at the upcoming $e^{+}{e}^{-}$ linear colliders. Effects of SU(2) singlet, doublet and triplet leptoquark interactions are investigated. R-parity violating minimal supersymmetric standard model also allows certain kinds of lepton number violating interactions which are same as singlet leptoquarks with left-handed interactions. We have calculated the cross-section of $e^{+}{e}^{-}\to t\bar{t}$ in presence of the above interactions. With conservative values of lepton number violating coupling strengths we got enhancement of top-pair production cross-section in all of the above cases.