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Heavy quarks, Higgs scalars, B-mesons and Gauge interactions at high energy

The following problems were considered and discussed in 66 publications:

1.The research activity was devoted to different aspects of radiative corrections to intermediate vector bosons properties manifestations. Among other results it is necessary to stress the global fit of electroweak data which takes into account leading supersymmetric corrections.

2.In the supersymmetry (SUSY) and supergravity (SUGRA) theories a simple method for the diagonalisation of an n x n hierarchical mass matrix was suggested and used for the investigation of the Minimal SUSY Standard Model (MSSM) and the Next to Minimal such model (NMSSM). Simple expression for Higgs boson mass spectra in both these models were obtained in analytic form.

3.The eminent achievement was a "generalised factorisation" - a new method to include non-facotrizable contributions to nonleptonic decays. This method is now widely applied by many authors in particular for the elevation of B decays to light mesons. Also the eta-eta' mixing problem and the charm content of the eta- meson were investigated.

4.The connection between heavy (e.g. b, c or s) quark decay rates in the free state and bound inside mesons or hyperons was established. It has the simplest form in the constituent quark model formulated on the light cone, with the used of a nonperturbative wave function for the internal motion of the decaying meson. The form-factors for a number of exclusive weak transitions of heavy mesons were calculated and the accuracy of the factorisation approximation for the nonleptonic decays of heavy mesons was investigated. Review papers on decays of these mesons were published.

5.The Multiple Point Principle (MPP) asserts that physical parameters tend to have fine-tuned values corresponding to the junction of all possible "phases" in a generalised action parameter space. Together with the Anti-Grand Unified Theory (AGUT) gauge group, the MPP yields remarkably good predictions of the three gauge coupling constants and gives at least approximately correct values of virtually all Standard Model free parameters. The MPP implies a phenomenlogically acceptable form of long range non-locality that is inextricably related to a MPP based model for the fine-tuning of physical quantities.

6.The investigation of the quark-lepton mass hierarchy problem was developed within AGUT, assuming the fundamental Yukawa couplings are all of order unity at the Planck scale. A successful fit to the charged fermion spectrum was obtained.

7.The phase transition phenomena and the role of the monopoles were investigate in gauge theories. The different regularisation schemes were considered in the AGUT. The approximate "universality" (regularisation independence) of critical coupling constants was established.

8.The evolution of running QCD constant αs (µ) was computed in the 4-loop approximation of the Gell-Mann-Low β-function. The value of gluon condensate was estimated.

Contact

H.B. NIELSEN
Tel.: +45-35325259
Fax: +45-31421016
Record Number: 24258 / Last updated on: 2000-03-28
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Stage of development: Other