Impact of double-logarithmic electroweak radiative corrections on the non-singlet structure functions at small x

In the QCD context, the non-singlet structure functions of u and d -quarks are identical, save the initial quark densities. Electroweak radiative corrections, being flavor-dependent, bring further difference between the non-singlets. This difference is calculated in the double-logarithmic approximation and the impact of the electroweak corrections on the non-singlet intercepts is estimated numerically.Comment: 17 pages, no figure

On the forward-backward charge asymmetry in e+e- -annihilation into hadrons at high energies

The forward-backward asymmetry in e+ e- annihilation into a quark-antiquark pair is considered in the double-logarithmic approximation at energies much higher than the masses of the weak bosons. It is shown that after accounting to all orders for the exchange of virtual photons and W, Z -bosons one is lead to the following effect (asymmetry): quarks with positive electric charge (e.g. u, \bar{d}) tend to move in the e+ - direction whereas quarks with negative charges (e.g. d, \bar{u}) tend to move in the e- - direction. The value of the asymmetry grows with increasing energy when the produced quarks are within a cone with opening angle, in the cmf, \theta_0\sim 2M_Z/\sqrt{s} around the e+e- -beam. Outside this cone, at \theta_0 << \theta << 1, the asymmetry is inversely proportional to \theta .Comment: 17 Pages, 2 Tables, 4 Figures. Hadronization effects to the asymmetry are considered with more detail

Mentorship in Higher Education: a Concept, a Model and Development Prospects

The article examines the mentorship development in higher education. The need for a scientific reconsideration of the conceptual framework of mentorship in modern conditions, as well as its important practical significance for adapting students, improving the quality of education and professional activity are forming the relevance of this topic. The purpose of the article is to develop the concept of mentorship, to design a model and to plan the mentoring in higher education. An interdisciplinary approach was used to determine the essence of mentorship (consideration of the category in Psychology and Sociology, Pedagogy, Management), a model of mentorship in higher education has been developed with a structural-system analysis, as well as with graphical and statistical methods. The scientific novelty of the article is the development of the conceptual framework of mentoring and applied aspects of its implementation in higher education in Russia. The essential elements of mentorship were identified and considered, namely: the concept and approaches, purpose and objectives, principles and functions. The types of mentorship in higher education were classified according to key criteria: the number of mentees, formalization, period of interaction, method of implementation, direction of interaction, purpose. The main principles of mentoring in higher education are specified. A model of mentoring in higher education was proposed. A systematic analysis of successful practices and mentoring programs in higher education in Russia was carried out. The problems and prospects for mentorship development in modern conditions were identified. The practical significance of the study lies in the possibility of using conceptual developments in the formation and development of the legal framework for the implementation of mentoring, as well as the development and implementation of a mentoring model in higher education institutions

Perturbative power Q^2-corrections to the structure function g(1)

We prove that regulating infrared divergencies generates power (~1/(Q^2)^k) corrections to the spin structure function g_1 at small x and large Q^2. At the same time it leads to the corrections ~(Q^2)^k at small Q^2. We present the explicit series of such terms as well as the formulae for their resummation. These contributions are not included in the standard analysis of the experimental data. We argue that accounting for such terms can sizably change the impact of the other power corrections conventionally attributed to the higher twists.Comment: Theoretical grounds for our approach are considered in much more detailed way than in the previous version; 10 pages, 2 figure