# why are two higgs doublets required in SUSY?

I can't really understand why two higgs doublets are required in SUSY.

From the literature, I have found opaque explanations that say something along the lines of: the superpotential W must be a holomorphic function of the chiral supermutiplets and thus we need to introduce another chiral supermutiplet.

I also know that this is somehow related to an anomaly cancellation. Can somebody help to make this a bit more clear?

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There's one more supersymmetric reason why we need two Higgs doublets: the Yukawa couplings must be holomorphic, arising from a superpotential $W=y\cdot h \bar q_L q_R$, and when one distinguishes chiral superfields and antichiral superfields (their complex conjugate), he finds out that only the up-type quarks (or only the down-quark quarks) could get masses from one Higgs doublet (the charges wouldn't add up to zero if you added the opposite quarks). So the opposite, complex conjugate Higgs doublet superfield (whose higgsinos have the opposite handedness for the same sign of the supercharge and the weak isospin) is needed to give masses to the remaining one-half of the quarks.