Electroweak Parameters from Mixed SU(2) Yang–Mills Thermodynamics

Based on the thermal phase structure of pure SU(2) quantum Yang–Mills theory, we describe the electron at rest as an extended particle, a droplet of radius r0∼a0, where a0 is the Bohr radius. This droplet is of vanishing pressure and traps a monopole within its bulk at a temperature of Tc=7.95 keV. The monopole is in the Bogomolny–Prasad–Sommerfield (BPS) limit. It is interpreted in an electric–magnetically dual way. Utilizing a spherical mirror-charge construction, we approximate the droplet’s charge at a value of the electromagnetic fine-structure constant α of α−1∼134 for soft external probes. It is shown that the droplet does not exhibit an electric dipole or quadrupole moment due to averages of its far-field electric potential over monopole positions. We also calculate the mixing angle θW∼30°, which belongs to deconfining phases of two SU(2) gauge theories of very distinct Yang–Mills scales (Λe=3.6 keV and ΛCMB∼10−4 eV). Here, the condition that the droplet’s bulk thermodynamics is stable determines the value of θW. The core radius of the monopole, whose inverse equals the droplet’s mass in natural units, is about 1% of r0.