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V. V. Kiselev

Publications and source records attributed to V. V. Kiselev.

120 records · Page 7Linked to original sources
arXiv1994

Semileptonic $B\to D^{(*)}lν$ decays, the slope of Isgur-Wise function and $|V_{bc}|$ value in potential quark model

The modification of the naive potential model of the heavy meson is considered on the basis of the single-time prescription for the quark-meson form factor and the covariant choice of the quatk relative momentum. The application of the model to the description of the semileptonic decays of the beauty meson allows one to determine the Isgur-Wise function slope $ρ^2\simeq 1.25$ and to extract the value $|V_{bc}|= 0.038\pm 0.003$ from the experimental data.

hep-ph↗
arXiv1994

Lambda-bar from QCD sum rules for heavy quarkonium

Using a specific scheme of the QCD sum rules for heavy quarkonium in the leading approximation over the inverse heavy quark mass, one gets the estimate of the difference between the masses of the heavy meson and heavy quark $\bar Λ= 0.59\pm 0.02$ GeV.

hep-ph↗
arXiv1994

Double charmed baryon production at B-factory

The cross-section for the double charmed baryon production at a $B$-factory is estimated on the basis of the perturbative QCD calculations for the $c c$-diquark production as well as of the quark-hadron duality.

hep-ph↗
arXiv1994

Scaling Properties of $S$-wave Level Density for Heavy Quarkonium from QCD Sum Rules

In the framework of a specific scheme of the QCD sum rules for $S$-wave levels of the heavy quarkonium, one derives an expression, relating the energetic density of quarkonium states and universal characteristics in the heavy quarkonium physics, such as the difference between the masses of a heavy quark $Q$ and meson $(Q\bar q)$ and the number of heavy quarkonium levels below the threshold of $(Q\bar Q) \to (Q\bar q) + (\bar Q q)$ decay.

hep-ph↗
arXiv1994

Masses of $nS$-wave Heavy Quarkonium Levels from QCD Sum Rules

Using a specific scheme of the QCD sum rules, one derives an universal formula for the mass differences for the $nS$-levels of heavy qiarkonium. This relation does not depend on the flavours of the heavy quarks, composing the quarkonium, and it is in a good agreement with the experimental mass values for the $ψ$- and $Υ$-families.

hep-ph↗
arXiv1994

$B_c$ spectroscopy

In the framework of potential models for heavy quarkonium the mass spectrum for the system ($\bar b c$) is considered. Spin-dependent splittings, taking into account a change of a constant for effective Coulomb interaction between the quarks, and widths of radiative transitions between the ($\bar b c$) levels are calculated. In the framework of QCD sum rules, masses of the lightest vector $B_c^*$ and pseudoscalar $B_c$ states are estimated, scaling relation for leptonic constants of heavy quarkonia is derived, and the leptonic constant $f_{B_C}$ is evaluated.

hep-ph↗
arXiv1994

Scaling behaviour of leptonic decay constants for heavy quarkonia and heavy mesons

In the framework of QCD sum rules one uses a scheme, allowing one to apply the conditions of both nonrelativistic heavy quark motion inside mesons and independence of nonsplitting nS-state density on the heavy quark flavours. In the leading order an analitic expression is derived for leptonic constants of both heavy quarkonia and heavy mesons with a single heavy quark. The expression allows one explicitly to determine scaling properties of the constants.

hep-ph↗
arXiv1994

Model for anomalous $Υ'' \to Υππ$ transition with account of chiral phase shift in hadron bag of quarkonium

We assume that a rather large bag of the $Υ''(3S b\bar b)$ heavy quarkonium is in the phase of spontaneously broken chiral symmetry, in contrast to the $Υ(1S b \bar b)$ hadron bag, having small size and being in the phase of exact chiral symmetry, so that the shift of the phases in the $Υ'' \to Υππ$ transition is the additional source for the $ππ$ pairs. This source causes an anomalous $ππ$ invariant mass distribution, which is experimentally observed.

hep-ph↗
arXiv1994

Production of four heavy quarks and $B_c$-mesons at the $Z^0$-boson pole

The cross-section for the production of $b{\bar b} c{\bar c}$ quarks in $e^+e^-$ annihilation, that proves to be at a level of $σ(e^+e^- \rightarrow b{\bar b} c{\bar c})/ σ(e^+e^- \rightarrow b{\bar b}) \sim 10^{-2}$ for ${\sqrt s}=M_Z$ is calculated within the frames of the QCD perturbation theory. The cross sections for the associated production of $1S$- and $2S$-wave states of $B_c$-meson in the reaction $e^+e^- \rightarrow B_c b{\bar c}$ were calculated in the nonrelativistic model of a heavy quarkonium. The fragmentation function of $b\to B_c^{(*)}$ is analysed in the scaling limit. The number of $Λ_{bc}$-hyperons to be expected at LEP is estimated on the basis of the assumption on quark-hadron duality.

hep-ph↗
arXiv1994

Scaling law for the $Υ(4S) \to B \bar B$ and $ψ(3770) \to D \bar D$ decay constants from effective sum rules

Sum rules for exclusive production of heavy meson pairs in $e^+e^-$ annihilation are used to evaluate the $Υ(4S) \to B \bar B$ and $ψ(3770) \to D \bar D$ decay widths. Infinitely heavy quark limit is discussed, so that scaling law for the quarkonium-meson coupling constant is derived. A value of the $B\bar B$ pair contribution into the leptonic constant $f_{Υ(4S)}$ is estimated.

hep-ph↗