It is well known, although sometimes ignored, that not only the d=5 but also d=6 proton decay depends on fermion mixings. In general we study carefully the dependence of d=6 decay on fermion mixings using the effective operator approach. We find that without specifying a theory it is impossible to make clear predictions. Even in a given model, it is often not possible to determine all the physical parameters. We point out that it is possible to make a clear test of any grand unified theory with symmetric Yukawa couplings. We discuss in some detail realistic theories based on SU(5) and SO(10) gauge symmetry. © 2004 Elsevier B.V. All rights reserved.
Fileviez Pérez, P. (2004). Fermion mixings vs d = 6 proton decay. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 595(1–4), 476–483. https://doi.org/10.1016/j.physletb.2004.06.061