Higher-dimensional operators in SUSY SO(10) GUT models

Abstract SO ( 10 ) GUT models with only small Higgs fields use higher-dimensional operators to generate realistic fermion mass matrices. In particular, a Higgs field in the spinor representation, 16 H d , acquires a weak scale vev. We include the weak vev of the corresponding field 16 ¯ H u and investigate its effects based on two successful models, one by Albright and Barr (AB) and another by Babu, Pati and Wilczek (BPW). We find that the BPW model is a particular case within a class of models with identical fermion masses and mixings. In contrast, we expect corrections to the parameters of AB-type models.