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Particle physics beyond the Standard Model

The discovery of the Higgs boson confirmed that the Standard Model describes physics at the electroweak scale – around 246 gigaelectronvolts. EU-funded scientists attempted to extrapolate this theory of particle physics up to very high scales.
Particle physics beyond the Standard Model
Current experimental uncertainty does not allow to make accurate predictions up to the Planck scale (around 1.22 × 1019 GeV). Within the framework of the EU-funded project IEET2 (Evolution equations for composite operators and AdS/CFT integrability), the scientists extended previous work on Higgs boson potential parameters in the Yukawa sector.

The Yukawa sector contains a large number of parameters that must be carefully adjusted to obtain realistic spectra of particles and mixings. From the 17 parameters needed to describe the electroweak theory, 13 come from the Yukawa sector. In addition, Yukawa couplings contain parameters that cannot be observed because they can be removed from the Lagrangian.

The scientists started with the Lagrangian of the Standard Model with full flavour structure. Their calculations relied on Feynman diagrams with explicit flavour indices. The results are of importance not only in the analysis of different flavour patterns that can originate from new physics and future studies of the Standard Model vacuum stability.

A series of papers were published on the beta-functions defined for parameters of the Higgs potential in the case of complex Yukawa matrices describing the flavour structure. The scientists also derived exact corrections to the so-called double-logarithmic evolution equations. These equations provide information about the scattering of elementary particles during their interactions.

All precision computations conducted during the IEET2 project demanded development of new methods. All calculations of planar and non-planar Feynmann diagrams were carried out in an almost automated way. To achieve this, the scientists relied on the infrared rearrangement procedure that was implemented in their codes.

The IEET2 project has established a connection between theoretical research with toy models and applications of the obtained results for the development of more realistic theories. This can be used to describe how the smallest building blocks of matter interact.

Related information


Particle physics, Standard Model, IEET2, Higgs boson potential, Yukawa sector, Feynmann diagrams, evolution equations
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