10,536 research outputs found
Nuclear Schiff moment and soft vibrational modes
The atomic electric dipole moment (EDM) currently searched by a number of
experimental groups requires that both parity and time-reversal invariance be
violated. According to current theoretical understanding, the EDM is induced by
the nuclear Schiff moment. The enhancement of the Schiff moment by the
combination of static quadrupole and octupole deformation was predicted
earlier. Here we study a further idea of the possible enhancement in the
absence of static deformation but in a nuclear system with soft collective
vibrations of two types. Both analytical approximation and numerical solution
of the simplified problem confirm the presence of the enhancement. We discuss
related aspects of nuclear structure which should be studied beyond mean-field
and random phase approximations.Comment: 14 pages, 4 figure
Nuclear Schiff moment in nuclei with soft octupole and quadrupole vibrations
Nuclear forces violating parity and time reversal invariance (-odd) produce -odd nuclear moments, for example, the
nuclear Schiff moment. In turn, this moment can induce the electric dipole
moment in the atom. The nuclear Schiff moment is predicted to be enhanced in
nuclei with static quadrupole and octupole deformation. The analogous
suggestion of the enhanced contribution to the Schiff moment from the soft
collective quadrupole and octupole vibrations in spherical nuclei is tested in
this article in the framework of the quasiparticle random phase approximation
with separable quadrupole and octupole forces applied to the odd Ra
and Rn isotopes. We confirm the existence of the enhancement effect
due to the soft modes. However, in the standard approximation the enhancement
is strongly reduced by a small weight of the corresponding "particle + phonon"
component in a complicated wave function of a soft nucleus. The perspectives of
a better description of the structure of heavy soft nuclei are discussed.Comment: 27 pages, 3 figures, minor corrections in references adde
Gauge invariant effective action for the Polyakov line in the SU(N) Yang--Mills theory at high temperatures
We integrate out fast varying quantum fluctuations around static A_4 and A_i
fields for the SU(N) gauge group. By assuming that the gluon fields are slowly
varying but allowing for an arbitrary amplitude of A_4 we obtain two variants
of the effective high-temperature theory for the Polyakov line. One is the
effective action for the gauge-invariant eigenvalues of the Polyakov line, and
it is explicitly Z(N) symmetric. The other is the effective action for the
Polyakov line itself as an element of the SU(N). In this case the theory
necessarily includes the spatial components A_i to ensure its gauge invariance
under spatial gauge transformations. We derive the 1-loop effective action in
the `electric' and `magnetic' sectors, summing up all powers of A_4.Comment: RevTex4, 2 figure
Deconfinement in Matrix Models about the Gross--Witten Point
We study the deconfining phase transition in SU(N) gauge theories at nonzero
temperature using a matrix model of Polyakov loops. The most general effective
action, including all terms up to two spatial derivatives, is presented. At
large N, the action is dominated by the loop potential: following Aharony et
al., we show how the Gross--Witten model represents an ultra-critical point in
this potential. Although masses vanish at the Gross--Witten point, the
transition is of first order, as the fundamental loop jumps only halfway to its
perturbative value. Comparing numerical analysis of the N=3 matrix model to
lattice simulations, for three colors the deconfining transition appears to be
near the Gross--Witten point. To see if this persists for N >= 4, we suggest
measuring within a window ~1/N^2 of the transition temperature.Comment: 22 pages, 7 figures; revtex4. A new Fig. 2 illustrates a strongly
first order transition away from the GW point; discussion added to clarify
relation to hep-th/0310285. Conclusions include a discussion of recent
lattice data for N>3, hep-lat/0411039 and hep-lat/050200
Potential energy and dipole moment surfaces of H3- molecule
A new potential energy surface for the electronic ground state of the
simplest triatomic anion H3- is determined for a large number of geometries.
Its accuracy is improved at short and large distances compared to previous
studies. The permanent dipole moment surface of the state is also computed for
the first time. Nine vibrational levels of H3- and fourteen levels of D3- are
obtained, bound by at most ~70 cm^{-1} and ~ 126 cm^{-1} respectively. These
results should guide the spectroscopic search of the H3- ion in cold gases
(below 100K) of molecular hydrogen in the presence of H3- ions
PETROGRAPHY AND MINERALOGY OF RETROGRADE METAPERIDOTITES FROM ALAG KHADNY ACCRETIONARY WEDGE (SW MONGOLIA): FLUID MODIFICATION IN SUPRASUBDUCTION ZONE
The Main Mongolian Lineament (MML) separates northern “Caledonian” tectonic province from southern “Hercynian” in SW part of Mongolia of the Central Asian Orogenic Belt (CAOB). The position of Eastern part of MML is widely discussed at recent time, since, this is an important for reconstruction of geodynamic evolution of this region. Some researchers suggest that ophiolite from the Erdene Uul and Maykhan Tsakhir Uul mountain ranges are Eastern part of an ophiolitic nappe system thrust northwards over the Dzabkhan-Baydrag continent, namely the Khantaishir and the Dariv ophiolites [Štípská et al., 2010; Buriánek et al., 2017]. Others have a different view, they suggest that investigated ophiolites refers to Gobi-Altai ophiolite system (523±5 – 518±6 Ma), which likely formed in front of the Gobi Altai microcontinent by initiation of a new southdipping subduction zone following arc–microcontinent collision in Northwest Mongolia [Jian et al., 2014]. However, ophiolites of this critical region of Mongolian the CAOB have not been investigated in detail.The Main Mongolian Lineament (MML) separates northern “Caledonian” tectonic province from southern “Hercynian” in SW part of Mongolia of the Central Asian Orogenic Belt (CAOB). The position of Eastern part of MML is widely discussed at recent time, since, this is an important for reconstruction of geodynamic evolution of this region. Some researchers suggest that ophiolite from the Erdene Uul and Maykhan Tsakhir Uul mountain ranges are Eastern part of an ophiolitic nappe system thrust northwards over the Dzabkhan-Baydrag continent, namely the Khantaishir and the Dariv ophiolites [Štípská et al., 2010; Buriánek et al., 2017]. Others have a different view, they suggest that investigated ophiolites refers to Gobi-Altai ophiolite system (523±5 – 518±6 Ma), which likely formed in front of the Gobi Altai microcontinent by initiation of a new southdipping subduction zone following arc–microcontinent collision in Northwest Mongolia [Jian et al., 2014]. However, ophiolites of this critical region of Mongolian the CAOB have not been investigated in detail
Prevalence of malocclusions under conditions of prolonged introduction of systemic fluorides in variable concentrations: Literature review
The pathogenesis of malocclusions, which are common among the population of all countries, is well represented in the professional literature. The occurrence of malocclusions is associated with genetic and various environmental factors. Among the latter, fluorides which affect the prevalence of some dental diseases are of particular interest. However, there are few publications reflecting the frequency of malocclusion among the population in the regions with different levels of fluoride in drinking water. This problem seems to be significant in the context of the increasing impact of fluorine compounds on human health, including dental health.The aim of the study. To analyze the literature on the frequency of malocclusion among the population living in conditions of variable fluoride content in drinking water. A manual search of domestic and foreign literature was performed in the search databases PubMed, Medline and Google Scholar. From the initial list of publications, eighteen articles that met the inclusion criteria for the study were selected for analysis. We revealed significant variability of the research results. Some authors note a higher prevalence of malocclusions among the population under conditions of increased fluoride intake, others note a lower one, and still others did not reveal any differences between the values obtained in both samples. Most of the assessed publications did not methodologically meet modern international standards, and therefore were of little evidence.The literature data do not provide grounds for an unambiguous assessment of fluorine compounds as an environmental factor that indirectly affects the process of occlusion formation in humans and animals.The review did not allow to make a definitive conclusion on the possible impact of systemic fluorides on the prevalence and pattern of malocclusion in humans and animals. It requires the implementation of studies that comply with the principles of evidence-based medicine
Transformation of the system of bilingual education in the Republic of Tatarstan: Crossover ethnolinguistic controversies
© 2017, Association for Social Studies Educa. All rights reserved. The relevance of the problem range addressed in the study is conditioned by the system of education functioning under multiculturalism in modern polyethnic societies and their social stability much depending on the balanced use of languages of ethnoses that reside in the region as well as on the respectful attitude to their representatives in daily life. Thus, the system of education has to take into account the ethnic and religious, political, social and cultural requirements of the society offering high-quality education to the consumers according to their expectations. The objective of the paper consists in revealing the topical problems of regional educational reforms aimed at implementing the principle of bilingualism in polyethnic and polyreligious region of Russia – the Republic of Tatarstan. The representative mass survey of population of the Republic of Tatarstan and a series of in-depth narrative interviews with representatives of various generations of Tatarstan citizens as the main methods used in the research. Based on the sociological survey conducted within the research project “Dynamics of real and conventional generations in information polyethnic and polyreligious society (a case study of the Republic of Tatarstan)”, the following findings have been made. Scientific justification of the language policy being implemented in the republic and of the methodological support of bilingual educational programs are of poor level. A higher education system segregated according to the information carrier language prevails. There also remains a crossover controversy expressed in discontent in both Russian-speaking and to a significant extent Tatar-speaking urban population with the school educational policy of bilingualism. Results of the research cited in the paper can be used by the state authorities of the republic for elaborating the optimum bilingual language policy as well as in the practice of educational institutions implementing the bilingual education
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