On the LHC signatures of $$SU(5)\times U(1)'$$ S U ( 5 ) × U ( 1 ) ′ F-theory motivated models

We study low energy implications of F-theory GUT models based on SU(5) extended by a $$U(1)'$$ symmetry which couples non-universally to the three families of quarks and leptons. This gauge group arises naturally from the maximal exceptional gauge symmetry of an elliptically fibred internal space, at a single point of enhancement, $$E_8\supset SU(5)\times SU(5)'\supset SU(5)\times U(1)^4.$$ Rank-one fermion mass textures and a tree-level top quark coupling are guaranteed by imposing a $$Z_2$$ monodromy group which identifies two abelian factors of the above breaking sequence. The $$U(1)'$$ factor of the gauge symmetry is an anomaly free linear combination of the three remaining abelian symmetries left over by $$Z_2$$ . Several classes of models are obtained, distinguished with respect to the $$U(1)'$$ charges of the representations, and possible extra zero modes coming in vector-like representations. The predictions of these models are investigated and are compared with the LHC results and other related experiments. Particular cases interpreting the B-meson anomalies observed in LHCb and BaBar experiments are also discussed.