CPT VIOLATION AND THE STANDARD MODEL

Spontaneous CPT breaking arising in string theory has been suggested a s a possible observable experimental signature in neutral-meson system s. We provide a theoretical framework for the treatment of low-energy effects of spontaneous CPT violation and the attendant partial Lorentz breaking. The analysis is within the context of conventional relativi stic quantum mechanics and quantum field theory in four dimensions. We use the framework to develop a CPT-violating extension to the minimal standard model that could serve as a basis for establishing quantitat ive CPT bounds.