John Gargalionis (IFIC, Valencia)
2:00pm Friday August 25, 2023
Geoff Opat Seminar Room
Proton decay in low-scale Pati–Salam models
The gauge bosons of Pati-Salam do not mediate proton decay at the renormalisable level, and for this reason it is possible to construct scenarios in which SU(4) x SU(2)_R is broken at relatively low scales. In this talk I discuss how such low-scale models generate dimension-5 operators that can generate nucleon decays at unacceptably large rates, even if the operators are suppressed by the Planck scale. This gives rise to an interesting complementarity between the nucleon-decay limits and the usual FCNC constraints. Furthermore, I will argue that these operators must be generated at tree-level in any sensible SO(10) embedding, lowering the suppression scale. Under reasonable assumptions, the lower limit on the breaking scale can be constrained to be as high as 10^8 GeV. The talk is based on the paper 2211.02054.