A perturbatively renormalized Abelian Higgs-Kibble model with a chirally coupled fermion is considered. The Slavnov identity is fulfilled to all orders of perturbation theory, which is crucial for renormalizability in models with vector bosons. BRS invariance, i.e. the validity of the identity, forces the chiral anomaly to be cancelled by Wess-Zumino counterterms. This procedure preserves the r...

The eikonal perturbation theory is formulated and applied to photoionization by strong laser pulses. A special emphasis is put on the first order approximation with respect to the binding potential, which is known as the generalized eikonal approximation [2015 Phys. Rev. A 91 053417]. The ordinary eikonal approximation and its domain of applicability is derived from the generalized eikonal appr...

Compatibility of the Reggeized form of QCD multi-particle amplitudes with the s-channel unitarity requires fulfilment of an infinite number of the " bootstrap " relations. On the other hand, it turns out that fulfillment of all these relations ensures the Reggeized form of energy dependent radiative corrections order by order in perturbation theory. It is extremely nontrivial, that all these re...

We describe a system of nodes in ?1; 1] s , where s 1 is an integer, with the following property. Suppose the values at these nodes of any target function f having a prescribed number r of continuous derivatives on ?1; 1] s are known. Given any > 0, we can construct a generalized translation network with O(?s=r) number of principal elements that approximates f uniformly within. Within a constan...

Dimensional Reduction is applied to QCD in order to compute various renor-malization constants in the DR scheme at higher orders in perturbation theory. In particular, the β function and the anomalous dimension of the quark masses are derived to three-loop order. Special emphasis is put on the proper treatment of the so-called ε-scalars and the additional couplings which have to be considered.

Renormalization-group methods in soft-collinear effective theory are used to perform the resummation of large perturbative logarithms for deep-inelastic scattering in the threshold region x → 1. The factorization theorem for the structure function F2(x,Q) for x → 1 is rederived in the effective theory, whereby contributions from the hard scale Q2 and the jet scale Q2(1 − x) are encoded in Wilso...

At low Q, charm production in deep-inelastic scattering is adequately described by assuming generation in electroweak boson-light parton scattering ~dominantly boson-gluon fusion!, which naturally incorporates the correct threshold behavior. At high Q this description is inadequate, since it does not sum logs in Q/mc , and is replaced by the treatment of the charm quark as a light parton. We sh...