Evanescent particles

Massive Klein-Gordon theory is quantized on a timelike hyperplane in Minkowski space using the framework of general boundary quantum field theory. In contrast to previous work, not only propagating sector phase quantized, but also evanescent sector, with correct physical vacuum. This yields for first time description quanta alone. The key tool novel $\alpha$-K\"ahler quantization prescription based $*$-twisted observable algebra. spatial evolution states between hyperplanes established and turns out be non-unitary if different choices are made ambiguity initial final hyperplane. Nevertheless, consistent notion transition probability case, thanks use positive formalism. Finally, it shown how conducting condition gives rise what we call Casimir state. pseudo-state which can interpreted as an alternative vacuum sea particle pairs even this static case.