We give an introduction to several regularization schemes that deal with ultraviolet and infrared singularities appearing in higher-order computations in quantum field theories. Comparing the...

This is the second in a series of two contributions in which we set out to establish a novel momentum space framework to treat field-theoretical infinities in perturbative calculations when parity-violating objects occur. Since no analytic continuation on the space-time dimension is effected, this framework can be particularly useful to treat dimension-specific theories. Moreover, arbitrary local terms stemming from the underlying infinities of the model can be properly parametrized. We (re)analyze the indeterminacy of the radiatively generated $\mathrm{CPT}$ violating Chern-Simons term within an extended version of ${\mathrm{QED}}_4$ and calculate the Adler-Bardeen-Bell-Jackiw triangle anomaly to show that our framework is consistent and general enough to handle the subtleties involved when a radiative correction is finite.

It is shown that $U(3)_L\times U(3)_R$ eight-quark interactions stabilize the asymmetric ground state of the well-known model with four-quark Nambu -- Jona-Lasinio and six-quark 't Hooft interactions. The result remains when the reduced SU(3) f\mbox{}lavour symmetry is explicitly broken by the general current quark mass term with $\hat{m}_u\neq\hat{m}_d\neq\hat{m}_s$.Comment: LaTeX, 17 pages, 2 figures, version to appear in Phys. Lett.

Induced nuclear fission is described as a transport process of the fission degree of freedom over the fission barrier. The lifetime of the event is defined in terms of the probability of finding the nuclear system in the potential well corresponding to the ground-state deformation. This definition appears as a natural generalization to nonstationary transport processes of the usual expression for the lifetime. Using the conservation law for the current we relate the lifetime to the time-integrated escape rate across the collective potential barrier.