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A. Z. Dubnickova

Publications and source records attributed to A. Z. Dubnickova.

At least 19 recordsLinked to original sources
arXiv2016

Numerical values of $f^F$, $f^D$, $f^S$ coupling constants in $SU(3)$ invariant interaction Lagrangian of vector-meson nonet with $1/2^+$ octet baryons

It is demonstrated how an utilization of all existing experimental information on electric and magnetic nucleon form factors, to be described by the Unitary and Analytic (U\&A) nucleon electromagnetic structure model in space-like and time-like regions simultaneously, can provide numerical values of $f^F$, $f^D$, $f^S$ coupling constants in $SU(3)$ invariant interaction Lagrangian of the vector-meson nonet with $1/2^+$ octet baryons. The latter, together with universal vector-meson coupling constants $f_V$, play an essential role in a prediction of $1/2^+$ octet hyperon electromagnetic form factors behaviors.

hep-ph↗
arXiv2014

Pion scalar form factor and model independent values of $f_0(500)$ and $f_0(980)$ meson parameters

The pion scalar form factor along with all existing S-wave iso-scalar $ππ$-scattering phase shift data in the elastic region up to $1 {\rm GeV}^2$ are applied for a determination of the $f_0(500)$ and $f_0(980)$ meson parameters $m_{f_0(500)}=(360\pm33){\rm MeV}$, $Γ_{f_0(500)}=(587\pm 85){\rm MeV}$ and $m_{f_0(980)}=(957\pm77) {\rm MeV}$, $Γ_{f_0(980)}=(164\pm142){\rm MeV}$ in a model independent way.

hep-ph↗
arXiv2010

Analyticity in a phenomenology of electro-weak structure of hadrons

The utility of an application of the analyticity in a phenomenology of electro-weak structure of hadrons is demonstrated in a number of obtained new and experimentally verifiable results. With this aim first the problem of an inconsistency of the asymptotic behavior of VMD model with the asymptotic behavior of form factors of baryons and nuclei is solved generally and a general approach for determination of the lowest normal and anomalous singularities of form factors from the corresponding Feynman diagrams is reviewed. Then many useful applications by making use of the analytic properties of electro-weak form factors and amplitudes of various electromagnetic processes of hadrons are carried out.

hep-ph↗
arXiv2007

Implication of the proton electric FF space-like behavior puzzle in various physical phenomena

By means of the 10-resonance unitary and analytic model of nucleon electromagnetic structure it is demonstrated that the JLab proton polarization data on the ratio $μ_p G_{Ep}(Q^2)/G_{Mp}(Q^2)$ are consistent with all form factor properties, however, they strongly require an existence of the zero in G_{Ep}(Q^2) around Q^2=13 GeV^2. As a result there are two contradicting behaviors of G_{Ep}(Q^2) in space-like region. Consequences of this phenomenon on the charge distribution within the proton, on the saturation of the new proton-neutron q^2-dependent sum rule, on the behavior of strange nucleon form factors and the deuteron elastic structure functions through the impulse approximation are investigated.

hep-ph↗
arXiv2007

Sum Rules for Total Cross-Sections of Hadron Photo-Production on Pseudoscalar Mesons and Octet Baryons

Considering very high energy peripheral electron-hadron scattering with a production of hadronic state X moving closely to the direction of initial hadron the Weizsäcker-Williams like expression, relating the difference of q^2-dependent differential cross-sections of DIS processes to the convergent integral over the difference of the total hadron photo-production cross-sections on hadros, is derived. Then, exploiting analytic properties of the forward retarded Compton scattering amplitude on the same hadrons, first, the sum rules are derived bringing into relation hadron electromagnetic form factors with the difference of the q^2-dependent differential cross-sections of DIS, then using Weizsäcker-Williams like expression and taking the derivative of both sides according to ${\bf q^2}$ for ${\bf q^2} \to 0$ one comes to new universal hadron sum rules relating hadron static parameters to the convergent integral over the difference of the total hadron photo-production cross-sections on hadrons.

hep-ph↗
arXiv2007

Sum rule for photon target

The amplitude of zero angle scattering of electron on photon in the 3-rd QED order of fine structure constant with $γ^*γ$ intermediate state converting into quark--antiquark is considered. Utilizing analytic properties of elastic photon--photon scattering amplitude an explicit expression for differential cross- section of quark--antiquark pair production at electron-photon collision in peripheral kinematics is derived apparently. Limiting case of small transferred momenta with an application of the Weizsäcker-Williams like relation gives the sum rule for photon target, bringing into the relation the sum of ratios of the four power of the quark charges to squared quark masses with integral over the total $γγ\to 2 jets$ cross--section.

hep-ph↗
arXiv2007

Radiative Kaon Decay in Chiral Perturbation Theory

We analyze the possibility of experimental investigation of new low-energy relations between the values of resonance masses in the meson form factors and the differential rate of radiative kaon decay $K^+\to π^+ e^+e^-(μ^+μ^- )$ at the current level of the experimental precision. A set of arguments is listed in favour of that these relations can be a consequence of weak static interactions in the Standard Model.

hep-ph↗
arXiv2007

Ground state $1/2^+$ octet baryon sum rules predicting a chain of inequalities for hadron photoproduction total cross-sections on corresponding baryons

Sum rules are derived relating Dirac mean square radii and anomalous magnetic moments of various couples of the ground state $1/2^+$ octet baryons with the convergent integral of the difference of hadron photoproduction cross-sections on the corresponding baryons. Taking into account the present knowledge of static parameters of baryons a chain of inequalities for total hadronic photoproduction cross-sections on baryons is found from those sum rules.

hep-ph↗
arXiv2006

Manifestation of the JLab proton polarization data on the behaviour of strange nucleon form factors

Special eight-resonance unitary and analytic model of nucleon electromagnetic structure is used to analyze, first the classical proton form factor data obtained by the Rosenbluth technique and then also the contradicting JLab proton polarization data on the ratio $μ_p G_{Ep}(Q^2)/G_{Mp}(Q^2)$ with the aim to investigate a manifestation of the latter on the strange nucleon form factors behaviour.

hep-ph↗
arXiv2006

Enhancement of the K --> pi Transition by the Instantaneous Weak Interactions

The hadrodynamics of the instantaneous weak interactions (IWI) in Standard Model is considered supposing the resonance nature of the chiral hadronization of quark currents in QCD. Exploiting this supposition and QCD symmetries the IWI mechanism of enhancement of the K+ --> pi+ transition probability is obtained and relations between electroweak meson form factors and the amplitudes of the processes K+ --> pi+ e+ e-(mu+ mu-,nu anti-nu) and K+ pi- --> e+ e-(mu+ mu-, nu anti-nu) are estalished. We estimate possible parameters of the K+ --> pi+ e+ e- decay rate in NA48/2 CERN experiment using the chiral perturbation theory.

hep-ph↗
arXiv2006

Instantaneous Interactions in Standard Model

Instantaneous interactions in Standard Model are derived by the resolution of the Gauss constraints in inertial reference frames defined as irreducible representations of the Poincare group. The relativistic covariant and gauge-invariant S-matrix is constructed with taking into account instantaneous interactions. Physical effects formed by the instantaneous interactions are discussed, including the enhancement in the kaon --> pion transition probability and the nonleptonic and semileptonic kaon decays. The low-energy relations between these decay probability amplitudes and meson form factors are established. Exploiting these relations we estimate possible parameters of the differential K \to πe^+ e^- decay rate in the NA48/2 CERN experiment.

hep-ph↗
arXiv2005

Unitary and analytic model of nucleon EM structure, the puzzle with JLab proton polarization data and new insight into proton charge distribution

The Unitary and analytic model of nucleon electromagnetic structure, describing all existing nucleon form factor data, is briefly reviewed. Then in the framework of this model the problem of inconsistency of older proton electric form factor data in space-like region (obtained from $% e^{-}p\to e^{-}p$ process by the Rosenbluth technique) with recent Jefferson Lab data on the ratio $G_{Ep}(t)/G_{Mp}(t)$ (measured in precise polarization $\overrightarrow{e}^{-}p\to e^{-}\overrightarrow{p}$ experiment) is suggested to be solved in favour of the latter data which, however, unlike older data cause an existence of the form factor zero, i.e. a difraction minimum in $|G_{Ep}(t)|$ around $t=-Q^{2}=-13$GeV$^{2}$. The new behaviour of $G_{Ep}(t)$ with the zero gives modified proton charge distribution with enlarged value of the mean square charge radius.

hep-ph↗