J. J. van der Bij
We describe the non-minimal Standard Model, consisting of minimalistic extensions of the Standard Model, which for all we know is the theory of the universe, able to describe all of the universe from the beginning of time. Extensions discussed are an extra neutrino and a new Higgs model. We introduce the principle of global relativity and discuss how the theory can be largely derived from this principle. One is led to the unification of forces into SU(5) and a form of dark matter. We discuss the limitations of the theory, showing that it is not the theory of everything. However we argue that it is the only part, that is within conceivable reach of physical experiment or astronomical observations. It is argued, that at the Planck scale the universe is effectively three-dimensional.
Comments: In memoriam Prof. M.J.G. Veltman, to appear in Acta Physica Polonica, 24 pages
Veltman, renormalizability, calculability: https://arxiv.org/abs/2104.13569
Dedicated to the memory of Prof. Veltman, one of the founding fathers of our discipline: his legacy lives on. Many times we have to turn back and follow his footprints to find the right path. After reviewing general aspects of high energy physics where he gave a seminal contribution we will introduce recent developments in the standard model effective field theory, showing how the whole movement from renormalization to predictions plays from Veltman to SMEFT.
Comments: to appear in Acta Physica Polonica, 27 pages
Goldstone boson decays and chiral anomalies: https://arxiv.org/abs/2105.04877
Stefan Pokorski, Kazuki Sakurai
Martinus Veltman was the first to point out the inconsistency of the experimental value for the decay rate of π0→γγ and its calculation by J. Steinberger with the very successful concept of the pion as the (pseudo)Nambu-Goldstone boson of the spontaneously broken global axial symmetry of strong interactions. That inconsistency has been resolved by J. Bell and R. Jackiw in their famous paper on the chiral anomalies. We review the connection between the decay amplitudes of an axion into two gauge bosons in Abelian vector-like and chiral gauge theories. The axion is the Nambu-Goldstone boson of a spontaneously broken axial global symmetry of the theory. Similarly as for the vector-like gauge theory, also in the chiral one the axion decay amplitude is uniquely determined by the anomaly of the current of that global symmetry. Certain subtlety in the calculation of the anomaly in chiral gauge theories is emphasised.
Comments: 13 pages, Contribution to the special volume of Acta Physica Polonica B commemorating Martinus Veltman