Half-monopole in the Weinberg-Salam model

We present new axially symmetric half-monopole configuration of the SU(2)×U(1) Weinberg-Salam model of electromagnetic and weak interactions. The half-monopole configuration possesses net magnetic charge 2π/e which is half the magnetic charge of a Cho-Maison monopole. The electromagnetic gauge potential is singular along the negative z-axis. However the total energy is finite and increases only logarithmically with increasing Higgs field self-coupling constant λ1/2 at sin2θW=0.2312. In the U(1) magnetic field, the half-monopole is just a one dimensional finite length line magnetic charge extending from the origin r=0 and lying along the negative z-axis. In the SU(2) 't Hooft magnetic field, it is a point magnetic charge located at r=0. The half-monopole possesses magnetic dipole moment that decreases exponentially fast with increasing Higgs field self-coupling constant λ1/2 at sin2θW=0.2312.