Comment on “SU(5) octet scalar at the LHC”
I address the validity of results presented in [S. Khalil, S. Salem, and M. Allam, Phys. Rev. D 89, 095011 (2014)] with regard to unification of gauge couplings within a particular SU(5) framework. The scalar sector of the proposed SU(5) model contains one 5- dimensional, one 24-dimensional, and one 45-dimensional representation. The authors discuss one specific unification scenario that supports the case for the LHC accessible color octet scalar. I show that the unification analysis in question is based on (i) an erroneous assumption related to the issue of nucleon stability and (ii) an incorrect input for the applicable set of renormalization group equations. This, in my view, invalidates the aforementioned gauge coupling unification study. I also question a source of the fermion mass relations presented in that work.