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S. G. Kovalenko

Publications and source records attributed to S. G. Kovalenko.

42 records · Page 3Linked to original sources
arXiv1995

New Supersymmetric Contributions to Neutrinoless Double Beta Decay.

The neutrinoless double beta ($\znbb$) decay is analyzed within the Minimal Supersymmetric Standard Model with explicit R-parity violation (\rp MSSM). We have found new supersymmetric contributions to this process and give the complete set of relevant Feynman diagrams. Operators describing $0^+ \longrightarrow 0^+$ nuclear transitions induced by the supersymmetric interactions of the \rp MSSM are derived. These operators can be used for calculating the $\znbb$ decay rate applying any specific nuclear model wave functions.

hep-ph↗
arXiv1994

Bounds on the Ratio of Higgs Vacuum Expectation Values in the Minimal Supersymmetric Standard Model from the Top and Bottom Quark Masses

The top quark mass values from the CDF Collaboration and the precision electroweak data at LEP combined with the bottom mass value allow to establish bounds on the parameter tan beta in the minimal supersymmetric standard model (MSSM) independent of the soft supersymmetry breaking parameters. We find: 0.96 < tan beta < 52.2 at the 95 % C.L., which is mostly the region tan beta >1, where radiative electroweak symmetry breaking is possible. Assuming electroweak symmetry breaking leads to: tan beta=1.2 +- 0.2, if one neglects the high tan beta solution, which is unlikely due to proton lifetime limits.

hep-ph↗
arXiv1994

Hidden Higgs Particle

A modification of the standard model of electroweak interactions with the nonlocal Higgs sector is proposed. Proper form of nonlocality makes Higgs particles unobservable after the electroweak symmetry breaking. They appear only as a virtual state because their propagator is an entire function. We discuss some specific consequences of this approach comparing it with the conventional standard model.

hep-ph↗
arXiv1994

Possible constraints on SUSY-model Parameters from Direct Dark Matter Search

We consider the SUSY-model neutralino as a dominant Dark Matter particle in the galactic halo and investigate some general issues of direct DM searches via elastic neutralino-nucleus scattering. On the basis of conventional assumptions about the nuclear and nucleon structure, without referring to a specific SUSY-model, we prove that it is impossible in principle to extract more than three constraints on fundamental SUSY-model parameters from the direct Dark matter searches. Three types of Dark matter detectors probing different groups of parameters are recognized.

hep-ph↗
arXiv1994

On SUSY Dark Matter Detection with Spinless Nuclei

We investigate the role of nuclear spin in elastic scattering of Dark Matter (DM) neutralinos from nuclei in the framework of the Minimal SUSY standard model (MSSM). The relative contribution of spin-dependent axial-vector and spin-independent scalar interactions to the event rate in a DM detector has been analyzed for various nuclei. Within general assumptions about the nuclear and nucleon structure we find that for nuclei with atomic weights $A > 50$ the spin-independent part of the event rate $R_{si}$ is larger than the spin-dependent one $R_{sd}$ in the domain of the MSSM parameter space allowed by the known experimental data and where the additional constraint for the total event rate $R =R_{sd} + R_{si} > 0.01$ is satisfied. The latter reflects realistic sensitivities of present and near future DM detectors. Therefore we expect equal chances for discovering the DM event either with spin-zero or with spin-non-zero isotopes if their atomic weights are $A_{1} \sim A_{2} > 50$.

hep-ph↗