Jet quenching in relativistic heavy ion collisions

Parton propagation in dense nuclear matter results in elastic, inelastic and coherent multiple soft scattering with the in-medium color charges. Such scattering leads to calculable modifications of the hadron production cross section that is evaluated in the framework of the perturbative QCD factorization approach. Final state medium-induced gluon bremsstrahlung is arguably the most efficient way of suppressing large transverse momentum particle production in nucleus-nucleus collisions. The observed hadronic attenuation, known as jet quenching, can be related to the properties of the medium, such as density and temperature, and carries valuable information about the early stages of heavy ion reactions. Non-Abelian energy loss in the quark-gluon plasma can be studied in much greater detail through the modification of the two particle back-to-back correlations. Perturbative calculations give good description of the redistribution of the lost energy in lower transverse momentum particles and predict significant increase of the correlation width of away-side di-hadrons. In contrast, energy loss in cold nuclear matter was found to be small but for large values of Feynman-x is expected to complement the dynamical higher twist shadowing in experimentally observable forward rapidity hadron suppression.Comment: Invited plenary talk at the V-th international conference on the physics and astrophysics of the quark-gluon plasma. 8 pages, 4 figure

Excitation of durable VHF oscillations in ferrite-filled coaxial lines

Effective methods are suggested for exciting gigahertz-range oscillations in coaxial lines that contain ferrite rings and isotropic material. Within the gyrotropic section, the primary pulsed waveform gets transformed from the TEM into a TM mode. Its further development is analyzed, following the results of real-life and numerical experiments. Special attention is paid to amplitude variations of the ТМ mode, owing to the nonlinear response of the ferrite.Пропонуються ефективні методи збудження осциляцій гігагерцевого діапазону в коаксіальних лініях, що містять уставки з феритових кілець та ізотропного матеріалу. У гіротропній частині лінії первинна імпульсна хвильова форма трансформується з моди ТЕМ у моду ТМ. Проаналізовано їх подальший розвиток за результатами відповідних натурних і числових експериментів. Особливої уваги приділено варіаціям амплітуди ТМ-моди, що пов’язані з нелінійністю електромагнітного відгуку фериту

Use of the Resources of Internet Network by Future Teachers of Physical Education and Specialists in Physical Education and Sport

Розкрито аспекти використання матеріалів мережі Internet майбутніми вчителями фізичної культури у Тернопільському національному педагогічному університеті імені Володимира Гнатюка в період 2008/2009 н. р., 2013/2014 н.р., 2016/2017 н. р. Зокрема, досліджено мету використання студентами internet-ресурсів (дистанційне навчання; виконання практичних, курсових і магістерських робіт та ІНДЗ; придбання товарів, спілкування, пошук роботи тощо), засоби електронного спілкування, тривалість роботи в мережі, використання електронних ресурсів університету (сайтів закладу освіти та факультетів, матеріалів Moodle та електронної бібліотеки), доступність мережі Internet для майбутніх фахівців фізичної культури та спорту. Встановлено, що змінилася мета використання internet-ресурсів. За даними дослідження 2017 р. більш ніж утричі зросла чисельність студентів, які розглядали Internet як засіб спілкування (78,6 % – спілкувалися з родиною, 92,8 % – з друзями). Основними засобами спілкування були соціальні мережі «Facebook» (90,5 %), «Контакти» (76,8 %), «Instagram» (33,3 %); комунікаційна система «Skype» (88,1 %), електронна пошта (66,7 %). Для пошуку друзів використовували Internet 47,6 % опитаних, для пошуку місця працевлаштування –45,2 %, як засіб заробітку–14,3 %. Абсолютним лідером серед пошукових систем став GOOGLE. Електронні ресурси навчальних курсів у системі Moodle використовували 90,5 % студентів, матеріали сайту університету – 54,8 %, сайту факультету – 45,2 %. Виявлено недостатній рівень використання майбутніми вчителями матеріалів головної ресурсної бази – електронної бібліотеки університет (42,8 %). Встановлено, що від початку дослідження до 78,6 % зріс відсоток студентів, які щоденно працювали у мережі понад 2 год. У 2017 р. лише 6,2 % опитаних використовували Internet менше 1 год. Матеріали дослідження можуть бути використані науковцями для порівняння й узагальнення даних у закладах вищої освіти.The aspects of the use of the materials of the Internet network by future teachers of physical education in Ternopil Volodymyr Hnatiuk National Pedagogical University for the period of 2008/2009, 2013/2014, 2016/2017 academic years were revealed. In particular, the aim of the use of the Internet-resources (distance learning, preparation of practical, course and master papers and individual educational-scientific projects, purchase of good, communication, job search, etc.), means of electronic communication, duration of the work in the network, use of electronic resources of the university (websites of the educational institution and faculties, materials Moodle, electronic library), availability of the Internet network to future specialist in physical education and sport, were studied. It was found that the purpose of Internet resources use has changed. According to the data of the study held in 2017, the number of students who saw the Internet as means of communication increased three times (78,6 % – communicated with family, 92,8 % – with friends). Main means of communication were social networks “Facebook”(90,5 %), “Vkontakte”(76,8 %), “Instagram” (33,3 %); communication system «Skype» (88,1 %), e-mail (66,7 %). 47,6% respondents used the Internet for friends search, 45,2% for job search, 14,3% as a means of earning. Google became the absolute leader among the search engines. 90,5% students used electronic resources of educational courses in the Moodle system, 54,8% – materials of the university website, 45,2% - of the faculty website. Insufficient level of the use of the materials of the main resource base – an electronic library of by future students (42,8%) was found. It was found that from the beginning of the research the percentage of the students who worked in the network daily for more than 2 hours increased to 78,6%. In 2017 only 6,2% respondents used the Internet for less than 1 hour. The material of the study may be used by the scientists for comparison and generalization of data in higher educational institutions

Morphometric study of the skeleton of the thorax in human fetuses aged 7-10 months

Introduction. It is necessary to clearly understand the norms of morphometric parameters of thorax during the fetal period of human ontogenesis, which is one of the main directions to solve the problem of modern normology. Objective. To trace the dynamics of changes of morphometric parameters of the bony thorax in human fetuses aged 7-10 months. Materials and methods. The anatomical study involved 39 human fetuses specimens of 231.0-375.0 mm of crown-rump length (CRL). The study was conducted by means of macro-microscopic preparation, morphometry and variation statistics method. Results. It was found that the length of the costal cartilage increases from rib I to VII and is the longest in the rib VII. The ribs are the highest along the midclavicular line. At the same time, the height of the ribs decreases along the posterior axillary line and becomes the shortest along the scapular line. It was revealed the greatest width of the II and III intercostal spaces along the parasternal and midclavicular lines. The width of the four superior intercostal spaces along the midclavicular line on the right and on the left is larger than the height of the corresponding ribs. The width of the II-X intercostal spaces on the right and on the left along the scapular lines exceeds the height of the corresponding ribs in 1.33-1.65 times. The greatest width of the II, IV and VII intercostal spaces was along the posterior axillary line both sided. The greatest width of the II, IV and X of the intercostal spaces was noted along the scapular lines. Conclusions. The length of the costal cartilage increases from rib I to VII and is the largest in VII ones. The smallest value of the length of the costal cartilage was found in the rib XII. During the 7th-10th months of the intrauterine development, an intensive increase in the length of costal cartilages of the ribs I-III occurs, on average, by 1.5 times, and there is a slow increase in the length of the costal cartilage of the rib VII. The ribs along the midclavicular line are the highest. At the same time, the height of the ribs decreases along the posterior axillary line and along the scapular line it is the lowest

An Organizational Approach to the Assessment of the Reengineering of the Enterprise’s Business Processes

In the context of constant aggravation of competition, when the speed of response of all subsystems of the enterprise along with the efficiency of activities are of particular importance, one of the effective instruments aimed at improving the functioning of the enterprise is the reengineering of business processes, since it radically changes the existing process model of business to an innovative model that is more adaptive to the existing realities of an economic entity. Effective use of technologies and instruments for reengineering of business processes allows the enterprise to become more flexible and adaptive to changes in the external environment, and as a result, more competitive in the business environment. Therefore, the study of the scientific problem of the application of the conception of reengineering and its implementation by enterprises in today’s conditions is an urgent task of both scientists and practitioners. The aim of the article is to develop an algorithm for evaluating the process of reengineering of the enterprise’s business processes. The article proves the relevance of the conception of reengineering of the business processes of enterprise by analyzing the evolution, formation, and the current development of this sphere of knowledge; the importance of information technologies in the management of the system of processes and modeling of the business processes of enterprise is determined; the stages of the procedure for reengineering of the business processes of enterprise are substantiated and the role and status of personnel in these changes are determined; an integrated organizational approach to assessing the process of reengineering of the the enterprise’s business processes has been substantiated. The purpose of the research was achieved with the help of a system of methods, in particular analysis and synthesis, induction and deduction – to determine the essence and features of the object and subject of research, scientific abstraction, logical analysis, comparison – to establish the causes, factors, and consequences of influence on the object and subject of research; integrated and system approach – to assess the process of reengineering of the business processes of the enterprise. Further scientific research on the subject of research will be based on the rapid development of modern technologies with the progressive informatization of society, which will lead to new conceptions and approaches both to the organization of reengineering and to the evaluation of its results

Lambda production in 40 A GeV/c Pb-Au collisions

During the 1999 lead run, CERES has measured hadron and electron-pair production at 40 A GeV/c beam momentum with the spectrometer upgraded by the addition of a radial TPC. Here the analysis of lambda and antilambda will be presented.Comment: 8 pages, 8 figures. 6th International Conference on Strange Quarks in Matter, Frankfurt 200

Semi-Hard Scattering Unraveled from Collective Dynamics by Two-Pion Azimuthal Correlations in 158 A GeV/c Pb + Au Collisions

Elliptic flow and two-particle azimuthal correlations of charged hadrons and high-$p_T$ pions ($p_T>$ 1 GeV/$c$) have been measured close to mid-rapidity in 158A GeV/$c$ Pb+Au collisions by the CERES experiment. Elliptic flow ($v_2$) rises linearly with $p_T$ to a value of about 10% at 2 GeV/$c$. Beyond $p_T\approx$ 1.5 GeV/$c$, the slope decreases considerably, possibly indicating a saturation of $v_2$ at high $p_T$. Two-pion azimuthal anisotropies for $p_T>$ 1.2 GeV/$c$ exceed the elliptic flow values by about 60% in mid-central collisions. These non-flow contributions are attributed to near-side and back-to-back jet-like correlations, the latter exhibiting centrality dependent broadening.Comment: Submitted to Phys. Rev. Letters, 4 pages, 5 figure

Elliptic flow of charged pions, protons and strange particles emitted in Pb+Au collisions at top SPS energy

Differential elliptic flow spectra v2(pT) of \pi-, K0short, p, \Lambda have been measured at \sqrt(s NN)= 17.3 GeV around midrapidity by the CERN-CERES/NA45 experiment in mid-central Pb+Au collisions (10% of \sigma(geo)). The pT range extends from about 0.1 GeV/c (0.55 GeV/c for \Lambda) to more than 2 GeV/c. Protons below 0.4 GeV/c are directly identified by dE/dx. At higher pT, proton elliptic flow v2(pT) is derived as a constituent, besides \pi+ and K+, of the elliptic flow of positive pion candidates. The retrieval requires additional inputs: (i) of the particle composition, and (ii) of v2(pT) of positive pions. For (i), particle ratios obtained by NA49 were adapted to CERES conditions; for (ii), the measured v2(pT) of negative pions is substituted, assuming \pi+ and \pi- elliptic flow magnitudes to be sufficiently close. The v2(pT) spectra are compared to ideal-hydrodynamics calculations. In synopsis of the series \pi- - K0short - p - \Lambda, flow magnitudes are seen to fall with decreasing pT progressively even below hydro calculations with early kinetic freeze-out (Tf= 160 MeV) leaving not much time for hadronic evolution. The proton v2(pT) data show a downward swing towards low pT with excursions into negative v2 values. The pion-flow isospin asymmetry observed recently by STAR at RHIC, invalidating in principle our working assumption, is found in its impact on proton flow bracketed from above by the direct proton flow data, and not to alter any of our conclusions. Results are discussed in perspective of recent viscous dynamics studies which focus on late hadronic stages.Comment: 38 pages, 27 figures, 2 tables. Abstract and parts of introduction made more comprehensible; corrected typos; acknowledgement added. To appear in Nucl.Phys.

Modification of the rho meson detected by low-mass electron-positron pairs in central Pb-Au collisions at 158 A GeV/c

We present a measurement of $e^+e^-$ pair production in central Pb-Au collisions at 158$A$ GeV/$c$. As reported earlier, a significant excess of the $e^+e^-$ pair yield over the expectation from hadron decays is observed. The improved mass resolution of the present data set, recorded with the upgraded CERES experiment at the CERN-SPS, allows for a comparison of the data with different theoretical approaches. The data clearly favor a substantial in-medium broadening of the $\rho$ spectral function over a density-dependent shift of the $\rho$ pole mass. The in-medium broadening model implies that baryon induced interactions are the key mechanism to in-medium modifications of the $\rho$-meson in the hot fireball at SPS energy.Comment: Revised versio

Leptonic and charged kaon decay modes of the ϕ\phi meson measured in heavy-ion collisions at the CERN SPS

We report a measurement of $\phi$ meson production in central Pb+Au collisions at E$_{lab}$/A=158 GeV. For the first time in heavy-ion collisions, $\phi$ mesons were reconstructed in the same experiment both in the K$^+$K$^-$ and the dilepton decay channel. Near mid-rapidity, this yields rapidity densities, corrected for production at the same rapidity value, of 2.05 +- 0.14(stat) +- 0.25(syst) and 2.04 +- 0.49(stat)+-{0.32}(syst), respectively. The shape of the measured transverse momentum spectra is also in close agreement in both decay channels. The data rule out a possible enhancement of the $\phi$ yield in the leptonic over the hadronic channel by a factor larger than 1.6 at 95% CL.Comment: 11 pages, 4 figures,submitted to Phys. Rev. Let