Speaker: Prof. Masud Chaichian (University of Helsinki) http://www.helsinki.fi/~www_sefo/chaichian/ Time: Tuesday, April 10rd, 12(NOON)--1PM Room: Carslaw 352 Lunch: after the talk --------------------------------------------------- Title: CPT and Lorentz Invariance: Their Relation and Violation Abstract: in a CPT-violating but Lorentz-invariant interacting quantum field theory, elementary particles, such as leptons, quarks, Higgs, their supersymmetric partners, and their antiparticles remain identical even after the quantum corrections are taken into account. Thus the CPT invariance is not the responsible symmetry for the equality of the masses of an elementary particle and its antiparticle -- it is the Lorentz invariance. At the same time, if there exists a CPT violating interaction in Nature, for composite particles such as p-\bar{p}, \pi^+-\pi^-, K0-\bar{K0}, etc., as well as for bound states, such as hydrogen-antihydrogen, there are differences in their masses, due to different bound-state energies, in their total widths (life-times) and magnetic moments. Therefore, the experimental measurements on the latter characteristics of composite particles or bound systems would reveal the existence of a CPT-violating theory, although the theory is Lorentz invariant. ---------------------------------------------------