Unification of Gauge Coupling Constants in 5D Pati-Salam Model

The standard model of particle physics is currently an accepted theory at low energies; however, it doesn’t address the unification of gauge coupling constants. In this dissertation, the renormalization group equations at one loop order in the standard model, both in 4D and 5D, in addition to Pati-Salam model (4D and  5D)have been studied. We found, both analytically and numerically, that a natural and successful gauge coupling unification could be achieved in 4D Pati-Salam model with MR = 10 11 GeV, and that the unification occurred there at Λ = 10 13 GeVfurther in and 5D Pati-Salam model a unification occurred too with MR = 10 GeV and compactification scale= 10 GeV at high energy scale, these results show 𝑅 that the gauge coupling constants are almost unified at high energy in Pati-Salam model.