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Anna Z. Dubničková

Publications and source records attributed to Anna Z. Dubničková.

7 recordsLinked to original sources
arXiv2021

Definite evidence for physically incomprehensible inequality $σ_{tot}(e^+e^- \to n \bar n) > σ_{tot}(e^+e^- \to p \bar p)$

Though the neutron mass is larger than the proton mass and obviously one expects in $e^+e^-$ annihilation a creation of more $p \bar p$ pairs in comparison with $n \bar n$ at the same energy, just the opposite inequality for the corresponding total cross sections $σ_{tot}(e^+e^- \to n \bar n) > σ_{tot}(e^+e^- \to p \bar p)$ has been revealed in the analysis of only the present time existing proton electromagnetic form factors data by the unitary and analytic approach.

hep-ph↗
arXiv2019

Study of $B_s\to\ell^+\ell^-γ$ decays in covariant quark model

We study the rare radiative leptonic decays $B_s\to\ell^+\ell^-γ$ ($\ell=e,μ,τ$) within the Standard Model, considering both the structure-dependent amplitude and bremsstrahlung. In the framework of the covariant confined quark model developed by us, we calculate the form factors characterizing the $B_s\toγ$ transition in the full kinematical region of the dilepton momentum squared and discuss their behavior. We provide the analytic formula for the differential decay distribution and give predictions for the branching fractions in both cases: with and without long-distance contributions. Finally, we compare our results with those obtained in other approaches.

hep-ph↗
arXiv2016

Decay $B_s\to ϕ\ell^+ \ell^-$ in covariant quark model

Our article is devoted to the study of the rare $B_s\to ϕ\ell^+\ell^-$ decay where $\ell=μ,τ$. We compute the relevant form factors in the framework of the covariant quark model with infrared confinement in the full kinematical momentum transfer region. The calculated form factors are used to evaluate branching fractions and polarization observables in the cascade decay $B\to ϕ(\to K^+K^-)\ell^+\ell^-$. We compare the obtained results with available experimental data and the results from other theoretical approaches.

hep-ph↗
arXiv2015

Decay $B\to K^\ast(\to Kπ) \ell^+ \ell^-$ in covariant quark model

Our article is devoted to the study of the rare $B\to K^\ast \ell^+\ell^-$~decay where $\ell=e,μ,τ$. We compute the relevant form factors in the framework of the covariant quark model with infrared confinement in the full kinematical momentum transfer region. The calculated form factors are used to evaluate branching fractions and polarization observables in the cascade decay $B\to K^\ast(\to Kπ)\ell^+\ell^-$. We compare the obtained results with available experimental data and the results from other theoretical approaches.

hep-ph↗
arXiv2013

Decays $B_{s}\rightarrow J/ψ+η$ and $B_{s}\rightarrow J/ψ+η'$ in the framework of covariant quark model

The covariant quark model represents an appropriate theoretical framework to describe the recent results on $B_{s}\rightarrow J/ψ+η$ and $B_{s}\rightarrow J/ψ+η'$ decays from the Belle collaboration. In this article we present the main features of he covariant quark model together with details on some of its aspects and methods, which we consider to be important. Further we apply the model specifically to the studied decay processes and give numerical results on decay widths as they follow from the odel. We conclude that the model, with most of its parameters previously fixed from different processes, is able to incorporate the new measurements from the Belle experiment.

hep-ph↗