Biomedical subjects

Bohdan Grzadkowski

Publications and source records attributed to Bohdan Grzadkowski.

3 recordsLinked to original sources

PubMed2006

Difficulties for five-dimensional gauge-higgs unification.

We consider five-dimensional gauge theories where all fields propagate in the bulk and the fifth direction is compactified on the orbifold S1/Z2, and where the fifth components of the gauge bosons play the role of the standard model Higgs boson (gauge-Higgs unification). The gauge symmetry breaking is realized through the appropriate orbifold boundary conditions and through the Hosotani mechanism. We show that for any such theory (with neither brane gauge kinetic terms nor anomalous gauge-group factors) the assumption that the low-energy vector-boson spectrum consists of the W(+/-), Z, and gamma only, is inconsistent with the experimental requirements sin2thetaW approximately 1/4 and rho identical with mW2/(mZ2 cos2theta w) = 1.

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PubMed2004

CP violation from five-dimensional QED.

It is shown that QED in (1 + 4)-dimensional space-time, with the fifth dimension compactified on a circle, is, in general, a CP violating theory. Depending on the fermionic boundary conditions, CP violation may be either explicit (through the Scherk-Schwarz mechanism) or spontaneous (via the Hosotani mechanism). The fifth component of the gauge field acquires (at the one-loop level) a nonzero vacuum expectation value which, in the presence of two fermionic fields, leads to spontaneous CP violation when the boundary conditions are CP symmetric. Phenomenological consequences are illustrated by a calculation of the electric dipole moment for the fermionic zero modes.

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PubMed2002

Bounds on the Higgs-boson mass in the presence of nonstandard interactions.

The triviality and vacuum stability bounds on the Higgs-boson mass are derived in the presence of weakly coupled new interactions parametrized in a model-independent way by an effective Lagrangian. When the scale of new physics Lambda is below 50 TeV the triviality bound is unchanged but the stability lower bound is increased by 40-60 GeV if the effective Lagrangian parameters are O(1) at the scale Lambda. In this case a Higgs-boson mass close to its current lower experimental limit would indicate the presence of new physics at the scale of a few TeV.

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