Higgsless EW gauge-boson masses from K-K geometry with torsion

Abstract: In the classical Higgsless $M^4\times S^3\times S^1$ Kaluza-Klein gauge-theory vacuum, torsion-induced loss of the $SU(2)\times U(1)$ left-invariance generates a gauge-boson mass term, in co-existence with the gauge-field kinetic term in the vacuum Hilbert-Einstein action. This is compulsory in the sense that having one of these terms without the other would mean violation of basic theorems on holonomy. The effect could be lost only at the very high massless-EW energy scale, where the ground-state manifold approach for the gauge-theory vacuum would be inapplicable. Created, as they are, from and as part of pure geometry, these gauge-boson masses reproduce precisely the spectum of the well-known experimental result. The apparently exploitable geometric elegance and the ensuing fundamentally geometric origin of mass may provide new theoretical and experimental perspectives around and well above the EW scale.