The Price of an Electroweak Monopole

Understand

In a recent paper, Cho, Kim and Yoon (CKY) have proposed a version of the SU(2) $\times$ U(1) Standard Model with finite-energy monopole and dyon solutions.

• The CKY model postulates that the effective U(1) gauge coupling $\to \infty$ very rapidly as the Englert-Brout-Higgs vacuum expectation value $\to 0$, but in a way that is incompatible with LHC measurements of the Higgs boson $H \to \gamma \gamma$ decay rate.
• We construct generalizations of the CKY model that are compatible with the $H \to \gamma \gamma$ constraint, and calculate the corresponding values of the monopole and dyon masses.
• We find that the monopole mass could be $< 5.5$ TeV, so that it could be pair-produced at the LHC and accessible to the MoEDAL experiment.