Matrix model, Kutasov duality and factorization of Seiberg-Witten curves

We study the duality of N = 1 gauge theories in the presence of a massless adjoint field and massive quarks by calculating the superpotential using the Dighkgraaf-Vafa matrix model and by comparing with the previous result coming from Kutasov duality. The Kutasov duality method gives a result in which one instanton term is absent. The matrix model method confirms it and also shows that the absence of the one instanton term is related to the masslessness of the adjoint field.