Oscillations of high energy neutrinos in matter: Precise formalism and parametric resonance

We present a formalism for precise description of oscillation phenomena in matter at high energies or high densities, V > \Delta m^2/2E, where V is the matter-induced potential of neutrinos. The accuracy of the approximation is determined by the quantity \sin^2 2\theta_m \Delta V/2\pi V, where \theta_m is the mixing angle in matter and \Delta V is a typical change of the potential over the oscillation length (l \sim 2\pi/V). We derive simple and physically transparent formulas for the oscillation probabilities, which are valid for arbitrary matter density profiles. They can be applied to oscillations of high energy (E > 10 GeV) accelerator, atmospheric and cosmic neutrinos in the matter of the Earth, substantially simplifying numerical calculations and providing an insight into the physics of neutrino oscillations in matter. The effect of parametric enhancement of the oscillations of high energy neutrinos is considered. Future high statistics experiments can provide an unambiguous evidence for this effect.Comment: LaTeX, 5 pages, 1 figure. Linestyles in the figure corrected to match their description in the caption; improved discussion of the accuracy of the results; references added. Results and conclusions unchange

THE PROFESSIONAL CHOICE OF GRADUATES WITH A BACHELOR DEGREE AS A PROGNOSTIC TASK SOLUTION

Introduction. Nowadays, modern students graduate from higher education institutions in the conditions of unwarranted employment, and they are given full freedom of the professional choice after graduation. The aim of the research is to describe the process of the professional choice among graduates with an accredited bachelor degree as a prognostic task solution. Methodology and research methods. The research is based on the analysis and generalization of research literature on the issues of professional self-determination, the theory of anticipation, forecasting psychology, and modeling of predictive activity at the speech-thought level. The method of experiment was used as an empirical method wherein the predictive task was the stimulus material. Results and scientific novelty. The characteristic of a predictive task is given. The authors’ technique «Predictive Task: Professional Choice» is briefly presented; empirical data on professional intentions of graduates with a bachelors degree were collected during the approbation. The weakest links of the professional choice process among the students are revealed as follows: a lack of relevant system information for implementation of the professional choice; incompleteness  of professional self-identification and hypothetical thinking among students during their training in higher education institutions. Thus, the directions of further studies of professional self-determination of university graduates are planned: identification of psychological determinants; comparison of initial attitudes of employment of students of federal and regional higher education institutions; analysis of features of the professional choice of graduates of various specialties. Practical significance. The materials of the present research can form the basis for development of the practical recommendations to optimize pedagogical maintenance of professional self-determination of students of higher education institutions according to their education. In authors’ view, purposeful work on formation of professional identity and training of students in forecasting techniques is in need to reduce the contingent of the graduates who do not plan to find a job according to the specialty. Moreover, such fundamental work could lead to conscious professional self-determination and skills acquisition to cope with various professional tasks. Введение. Современные студенты заканчивают вузы в условиях негарантированной занятости и предоставления им полной свободы профессионального выбора после получения диплома о высшем образовании. Цель изложенного в публикации исследования – описать процесс профессионального выбора выпускниками бакалавриата как решение прогностической задачи. Методология и методики исследования. Работа базируется на анализе и обобщении литературы по проблемам профессионального самоопределения, теории антиципации, психологии прогнозирования, моделирования прогностической деятельности на речемыслительном уровне. В качестве эмпирического метода использовался эксперимент, стимульным материалом которого явилась прогностическая задача. Результаты и научная новизна исследования. Дана характеристика прогностической задачи. Кратко представлена авторская методика «Прогностическая задача: профессиональный выбор», в ходе апробации которой получены эмпирические данные о профессиональных намерениях выпускников-бакалавров. Выявлены наиболее слабые звенья процесса профессионального выбора учащейся молодежи: недостаток актуальной системной информации для осуществления данного выбора; несформированность профессиональной самоидентификации и гипотетического мышления у студентов в период их обучения в вузе. Обозначены направления дальнейших исследований профессионального самоопределения выпускников вузов: выявление его психологических детерминант; сравнение исходных установок трудоустройства у студентов федеральных и региональных вузов; анализ особенностей профессионального выбора выпускников различных профилей подготовки. Практическая значимость. Материалы исследования могут служить основанием для разработки практических рекомендаций, позволяющих оптимизировать педагогическое сопровождение профессионального самоопределения студентов вуза в соответствии с получаемым ими образованием. По мнению авторов статьи, для сокращения контингента выпускников, не планирующих трудоустраиваться в соответствии с получаемым дипломом, требуются целенаправленная работа по формированию профессиональной идентичности и обучение студентов методикам прогнозирования, помогающим как осознанному профессиональному самоопределению, так и приобретению умений справляться с разнообразными профессиональными задачами, принимая самостоятельные взвешенные решения. 

Chizhov and Petcov Reply

We have found in [1] new conditions for a total neutrino conversion in the case of neutrino oscillations taking place in a medium, consisting of n = 2 (or 3) alternating layers with constant densities $N_1$ and $N_2$. It is claimed in [4] that our results are particular case of enhancement of neutrino oscillations, which was suggested earlier by other authors and was widely discussed in the literature. We refute these claims, confirming the novelty of our results.Comment: 2 pages, LATEX; concise (essentially 1 page) and somewhat modified version of Ref. SISSA 5/2000/EP (hep-ph/0003110); reply on the ``Comment on New Conditions for a Total Neutrino Conversion in a Medium'', Phys. Rev. Lett. 85 (2000) 3978; published as ``Chizhov and Petcov Reply'' in Phys. Rev. Lett. 85 (2000) 397

Stimulated Neutrino Transformation with Sinusoidal Density Profiles

Large amplitude oscillations between the states of a quantum system can be stimulated by sinusoidal external potentials with frequencies that are similar to the energy level splitting of the states or a fraction thereof. Situations when the applied frequency is equal to an integer fraction of the energy level splittings are known as parametric resonances. We investigate this effect for neutrinos both analytically and numerically for the case of arbitrary numbers of neutrino flavors. We look for environments where the effect may be observed and find that supernova are the one realistic possibility due to the necessity of both large densities and large amplitude fluctuations. The comparison of numerical and analytic results of neutrino propagation through a model supernova reveals it is possible to predict the locations and strengths of the stimulated transitions that occur.Comment: 14 pages, 6 figure

Treatment of pain syndrome after aesthetic breast surgery with botulinum toxin type A

Objective. To justify the possibility of using botulotoxin type A for the prevention of pain syndrome after aesthetic endoprosthesis of the mammary glands.Material and Methods. The study included 72 women aged between 21 and 45 to whom were scheduled to perform breast endoprosthesis with silicone implants. All patients were divided into two groups: the first group included 38, the second group – 34 people. Two weeks before the expected date of surgery, botulotoxin type A in an amount of 100 U was injected into the patients of the first group to reduce pain syndrome in the pectoralis major muscle. Patients of the second (control) group were injected with a 0.9% NaCl solution (placebo effect) into the pectoralis major muscle. All patients underwent electroneuromyography (ENMG) to assess the denervation of the pectoralis major muscle before drug administration and two weeks after.Results. The intensity of pain syndrome was evaluated on the 1st-2nd day after surgery using a special questionnaire. In women of the first group, who were injected with botulinum toxin type A two weeks prior the intended surgery, a decrease in the intensity of the pain syndrome was observed, which in most cases allowed not to take analgesics at all. In women of the second group who were injected with a 0.9% NaCl solution, the severity of the pain syndrome reached its maximum values (according to the questionnaire), which required the prescription of analgesics, including narcotic ones, to reduce the severity of the pain syndrome. According to ENMG, when using botulotoxin type A by injecting into the pectoralis major muscle, denervation indices reached 55% compared to the initial ones, while using the saline solution, the ENMG indices did not change.Conclusion. Clinical use of botulotoxin type A injections into the pectoralis major muscle will improve the results of pain syndrome treatment after endoprosthetics of the mammary glands with implants in aesthetic surgery

The MSW effect and Matter Effects in Neutrino Oscillations

The MSW (Mikheyev-Smirnov-Wolfenstein) effect is the adiabatic or partially adiabatic neutrino flavor conversion in medium with varying density. The main notions related to the effect, its dynamics and physical picture are reviewed. The large mixing MSW effect is realized inside the Sun providing the solution of the solar neutrino problem. The small mixing MSW effect driven by the 1-3 mixing can be realized for the supernova (SN) neutrinos. Inside the collapsing stars new elements of the MSW dynamics may show up: the non-oscillatory transition, non-adiabatic conversion, time dependent adiabaticity violation induced by shock waves. Effects of the resonance enhancement and the parametric enhancement of oscillations can be realized for the atmospheric and accelerator neutrinos in the Earth. Precise results for neutrino oscillations in the low density medium with arbitrary density profile are presented and the attenuation effect is described. The area of applications is the solar and SN neutrinos inside the Earth, and the results are crucial for the neutrino oscillation tomography.Comment: 18 pages, latex, 6 figures, talk given at the Nobel Symposium 129, ``Neutrino Physics'', Haga Slott, August 19 - 24, 200

An accurate analytic description of neutrino oscillations in matter

A simple closed-form analytic expression for the probability of two-flavour neutrino oscillations in a matter with an arbitrary density profile is derived. Our formula is based on a perturbative expansion and allows an easy calculation of higher order corrections. The expansion parameter is small when the density changes relatively slowly along the neutrino path and/or neutrino energy is not very close to the Mikheyev-Smirnov-Wolfenstein (MSW) resonance energy. Our approximation is not equivalent to the adiabatic approximation and actually goes beyond it. We demonstrate the validity of our results using a few model density profiles, including the PREM density profile of the Earth. It is shown that by combining the results obtained from the expansions valid below and above the MSW resonance one can obtain a very good description of neutrino oscillations in matter in the entire energy range, including the resonance region.Comment: 16 pages,6 figure

Floquet theory of neutrino oscillations in the earth

We review the Floquet theory of linear differential equations with periodic coefficients and discuss its applications to neutrino oscillations in matter of periodically varying density. In particular, we consider parametric resonance in neutrino oscillations which can occur in such media, and discuss implications for oscillations of neutrinos traversing the earth and passing through the earth's core.Comment: LaTeX, 28 pages, 8 eps figures. Contribution to the special issue of Yad. Fiz. dedicated to the memory of A.B. Migda