New Method for Measuring the Ratio μpGE/GM\mu_p G_E/G_M Based on the Polarization Transfer from the Initial Proton to the Final Electron in the ep⃗→e⃗pe \vec p \to \vec e p Process

In this letter, we propose a new method for measuring the Sachs form factors ratio ($R =\mu_p G_E/G_M$) based on the transfer of polarization from the initial proton to the final electron in the elastic $e \vec p \to \vec e p$ process, in the case when the axes of quantization of spins of the target proton at rest and of the scattered electron are parallel, i.e., when an electron is scattered in the direction of the spin quantization axis of the proton target. To do this, in the kinematics of the SANE collaboration experiment (2020) on measuring double spin asymmetry in the $\vec e\vec p \to e p$ process, using Kelly (2004) and Qattan (2015) parametrizations, a numerical analysis was carried out of the dependence of the longitudinal polarization degree of the scattered electron on the square of the momentum transferred to the proton, as well as on the scattering angles of the electron and proton. It is established that the difference in the longitudinal polarization degree of the final electron in the case of conservation and violation of scaling of the Sachs form factors can reach 70%. This fact can be used to set up polarization experiments of a new type to measure the ratio $R$.Comment: 6 pages, 4 figures, 2 tables, for greater clarity, some minor additions have been mad

Scimago Institutions Rankings for the Assessment of National Education System and Particular University

The article analyzes the results of the Scimago Institutions Rankings for the entire period of its existence and presents the detailed description of the rating methodology and necessary condition for the inclusion in the ranking list, i.e. the publication of more than 100 works by university stuff in the Scopus database. There has been an almost twofold increase in the number of universities in the ten-year ranking lists. The article illustrates the dynamics for a number of countries and analyzes the reasons for their shifts. The competition between China and the United States is demonstrated. It is noted how the adoption of political decisions, such as the “May decrees” in the Russian Federation or projects “211”, “985” in China increase the number of universities in the country participating in the ratings. Such countries as Vietnam, Iran, Indonesia succeeded in multiplying their positions in the university rankings. The article estimates the rate of growth in the number of publications for university in order to maintain its position in the scientometric rankings. The research conducts the analysis of the time required by the ranking agencies to implement and reflect the changes initiated by state competitiveness improvement programs

Asymmetric transmission in planar chiral split-ring metamaterials: Microscopic Lorentz-theory approach

The electronic Lorentz theory is employed to explain the optical properties of planar split-ring metamaterials. Starting from the dynamics of individual free carriers, the electromagnetic response of an individual split-ring meta-atom is determined, and the effective permittivity tensor of the metamaterial is calculated for normal incidence of light. Whenever the split ring lacks in-plane mirror symmetry, the corresponding permittivity tensor has a crystallographic structure of an elliptically dichroic medium, and the metamaterial exhibits optical properties of planar chiral structures. Its transmission spectra are different for right-handed versus left-handed circular polarization of the incident wave, so the structure changes its transmittance when the direction of incidence is reversed. The magnitude of this change is shown to be related to the geometric parameters of the split ring. The proposed approach can be generalized to a wide variety of metal-dielectric metamaterial geometries

Elliptical dichroism: operating principle of planar chiral metamaterials

We employ a homogenization technique based on the Lorentz electronic theory to show that planar chiral structures (PCSs) can be described by an effective dielectric tensor similar to that of biaxial elliptically dichroic crystals. Such a crystal is shown to behave like a PCS insofar as it exhibits its characteristic optical properties, namely, co-rotating elliptical polarization eigenstates and asymmetric, direction-dependent transmission for left/right-handed incident wave polarization.Comment: 3 pages, version as accepted in Optics Letters but before final shortening

Possible Method for Measuring the Proton Form Factors in Processes with and without Proton Spin Flip

The ratio of the squares of the electric and magnetic proton form factors is shown to be proportional to the ratio of the cross sections for the elastic scattering of an unpolarized electron on a partially polarized proton with and without proton spin flip. The initial proton at rest should be polarized along the direction of the motion of the final proton. Similar results are valid for both radiative $ep$ scattering and the photoproduction of pairs on a proton in the Bethe--Heitler kinematics. When the initial proton is fully polarized in the direction of the motion of the final proton, the cross section for the $ep \to ep$ process, as well as for the $ep \to ep \gamma$ and $\gamma p \to e \bar e p$ processes, without (with) proton spin flip is expressed only in terms of the square of the electric (magnetic) proton form factor. Such an experiment on the measurement of the cross sections without and with proton spin flip would make it possible to acquire new independent data on the behavior of $G_E^2(Q^2)$ and $G_M^2(Q^2)$, which are necessary for resolving the contradictions appearing after the experiment of the JLab collaboration on the measurement of the proton form factors with the method of polarization transfer from the initial electron to the final proton.Comment: 7 pages, revtex