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G. S. Sharov

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

31 records · Page 2Linked to original sources
arXiv2001

Quasirotational Disturbances of Linear String Baryon Configuration

For the linear string baryon model $q$-$q$-$q$ the small disturbances of its rotational motion (quasirotational states) are investigated. The spectrum of these states is obtained in the form of Fourier series and the complex eigenfrequencies are found in this spectrum. So the classic rotational motions of the linear string baryon model are unstable (unlike the similar motions for the string with massive ends). This instability differs from its analog for the three-string baryon model.

hep-ph↗
arXiv2001

Special Classes of Solutions for Linear String Baryon Configuration

For the linear string baryon model with three material points (three quarks) joined sequentially by the relativistic strings, the class of motions admitting linearizable boundary conditions is investigated. These motions may be represented as the Fourier series with eigenfunctions of some boundary-value problem. The two types of rotational motions are found among the mentioned class of solutions.

hep-ph↗
arXiv2000

Black Hole Horizon in Superstring Inspired D-Dimensional Dilaton Gravity

In $D$-dimensional dilaton gravitational model stationary Schwarzschild type solutions (centrally symmetrical solutions in vacuum) are obtained. They contain the two-parameter set of solutions: the first parameter is proportional to a central mass and the second one describes intensity of the dilaton field. If the latter parameter equals zero we have pure Schwarzschild solution with the black hole and constant dilaton field. But when the mentioned parameter is non-zero and the dilaton is non-constant, the black hole horizon vanishes.

hep-th↗
arXiv2000

Excitations of Rotational States in String Model of Meson and in Three-string Baryon Model

For the relativistic string with massive ends, the three-string baryon model and other string models of the baryon the small disturbances of well known rotational motions are considered. For the string meson model the two types of these disturbances (quasirotational motions) are obtained. They are oscillatory motions in the form of stationary waves in the rotational plane and in the orthogonal direction. These solutions may be used for describing more wide spectrum of hadron excitations and for the quantization of this nonlinear system. For three-string baryon model or Y configuration these quasirotational motions are more complicated and contain the branch with growing amplitudes. This consideration proves that for the three-string model with both massless and massive ends the rotational motions are unstable on the classical level.

hep-ph↗
arXiv2000

Strings in Meson and Baryon Physics

The relativistic string with massive ends (the meson model) and four various string baryon models: q-qq, q-q-q, Y and $Δ$ are considered. In particular, the rotational motions for all these systems are applied to describing the leading Regge trajectories, and also the classical dynamics beyond the usual rectilinear string rotations is studied. For the string meson model the two types of quasirotational motions (disturbances of the planar uniform rotations) are obtained. They are oscillatory motions in the form of stationary waves in the rotational plane and in the orthogonal direction. The analysis of the stability problem for the rotational motions for all mentioned string configurations shows that these motions for the Y and q-q-q models are unstable on the classical level.

hep-ph↗
arXiv2000

Instability of Classic Rotational Motion for Three-String Baryon Model

The dynamics of baryon string model Y (three-string) is considered with using the approach that implies defining a classical motion of the system on the base of given initial position and initial velocities of string points. The analysis resulted, in particular, in the necessity of regarding more wide (than it was supposed earlier) class of parametrizations of the world surface for the adequate description of the three-string model. This approach let us to ascertain that the classic rotational motions (flat uniform rotations) for this string configuration are unstable. Any small asymmetric disturbances grow and inevitably result in falling a quark into the junction.

hep-ph↗
arXiv2000

Quasirotational Motions and Stability Problem in Dynamics of String Hadron Models

For the relativistic string with massive ends (the meson model) and four various string baryon models (q-qq, q-q-q, Y and $Δ$) we consider the classical quasirotational motions, which are small disturbances of the planar uniform rotations of these systems. For the string meson model the two types of these solutions are obtained. They describe oscillatory motions in the form of stationary waves in the rotational plane and in the orthogonal direction. This approach and the suggested method of determining an arbitrary motion of the system on the base of initial data let us solve the stability problem for the rotational motions for all mentioned string configurations. It is shown that the classic rotational motions are {\it stable} for the string meson model (or its analog q-qq) and for the $Δ$ baryon configuration, but they are {\it unstable} for the string baryon models Y and q-q-q. For the latter two systems any small asymmetric disturbances grow with growing time. The motion of the q-q-q configuration become more complicated and quasiperiodic but quarks do not merge. In the case of Y model the evolution of disturbances results in falling a quark into the junction. These features of the classic behavior are important for describing the hadron states on the Regge trajectories and for choosing and developing the most adequate QCD-based string hadron models.

hep-ph↗
arXiv1999

Hadronic Regge Trajectories: Problems and Approaches

We scrutinized hadronic Regge trajectories in a framework of two different models --- string and potential. Our results are compared with broad spectrum of existing theoretical quark models and all experimental data from PDG98. It was recognized that Regge trajectories for mesons and baryons are not straight and parallel lines in general in the current resonance region both experimentally and theoretically, but very often have appreciable curvature, which is flavor-dependent. For a set of baryon Regge trajectories this fact is well described in the considered potential model. The standard string models predict linear trajectories at high angular momenta J with some form of nonlinearity at low J.

hep-ph↗
arXiv1999

Initial-Boundary Value Problem and Stability of Solutions for String Baryon Model "Triangle"

For the string baryon model "triangle" the initial-boundary value problem is stated and solved in general. This problem implies defining a classical motion of the system on the base of given initial position and initial velocities of string points. The presented solution reduces the initial-boundary value problem for the considered model to the system of ordinary differential equations that can be integrated numerically in general. Using this approach we ascertain the stability of the rotational motions (flat uniform rotations) for the "triangle" string configuration.

hep-ph↗
arXiv1998

Rotational Stability of Linear String Baryon Configuration

For the linear baryon string model with three massive points (three quarks) connected sequentially by the relativistic strings the initial-boundary value problem is stated and solved in general. This problem implies defining a classical motion of the system on the base of given initial position and initial velocities of string points. The given solution work reduces the initial-boundary value problem for the considered model to the system of ordinary differential equations that can be integrated numerically in general. The examples of numerical simulation of the system motion are considered, which, in particular, allow to answer to the old question about stability of a flat uniform rotation of the linear string configuration.

hep-ph↗
arXiv1998

Four Various String Baryon Models and Regge Trajectories

Rotational motions for the quark-diquark (q-qq), linear (q-q-q) "three-string" (Y) and "triangle" string baryon models are considered and applied to description of baryonic orbitally exited states on the Regge trajectories. For the model "triangle" (three pointlike masses bounded pairwise by relativistic strings) the rotating closed string has a form of a curvilinear triangle composed of segments of a hypocycloid. The ultrarelativistic asymptotic relation between the energy $E=M$ and the total angular momentum $J$ has the same form $J\simeqα'E^2+α_1E^{1/2}$ for rotational states in all string baryon models. Taking into account some type of quark spin-orbit interaction one can describe the baryonic Regge trajectories by means of all mentioned string baryon configurations under assumption of different effective string tensions for them. Model depending estimations of effective quark masses in this procedure $m_{ud}\simeq 130$ MeV, $m_{s}\simeq 270$ MeV are close for all string configurations.

hep-ph↗
arXiv1998

String Baryon Model "Triangle": Hypocycloidal Solutions

The considered model of baryon consists of three pointlike masses (quarks) bounded pairwise by relativistic strings forming a curvilinear triangle. Classic analytic solutions for this model corresponding to a planar uniform rotation about the system center of mass are found and investigated. These solutions describe a rotating curve composed of segments of a hypocycloid. The curve is a curvilinear triangle or --- a more complicated configuration with a set of internal massless points moving at the speed of light. Different topological types of these motions are classified in connection with different forms of hypocycloids in zero quark mass limit. An application of these solutions to description of baryon states on the Regge trajectories is considered.

hep-th↗