Have Pentaquark States Been seen?

The status of the search for pentaquark baryons is reviewed in light of new results from the first two dedicated experiments from CLAS at Jefferson Lab and of new analyses from several laboratories on the $Theta^+(1540)$. Evidence for and against two heavier pentaquark states is also discussed.Comment: Added some references, corrected typo

Comment on The Evidence for a Pentaquark and Kinematic Reflections

The Regge exchange model used by Dzierba et al. is shown to be questionable, since the pion pole term is not allowed. Hence the Regge amplitudes in their calculation are exaggerated. The amount of kinematic reflection in the mass spectrum of the (nK+) system, which is one decay channel of a possible pentaquark, is not well justified in the fitting procedure used by Dzierba et al., as shown by comparison with the (K+K-) invariant mass spectrum, which is one decay channel of the a_2 and f_2 tensor mesons. While kinematic reflections are still a concern in some papers that have presented evidence for the pentaquark, better quantitative calculations are needed to demonstrate the significance of this effect.Comment: Comment submitted to Phys. Rev. D (no figures

Energy densities in quantum mechanics

Quantum mechanics does not provide any ready recipe for defining energy density in space, since the energy and coordinate do not commute. To find a well-motivated energy density, we start from a possibly fundamental, relativistic description for a spin-$\frac{1}{2}$ particle: Dirac's equation. Employing its energy-momentum tensor and going to the non-relativistic limit we find a locally conserved non-relativistic energy density that is defined via the Terletsky-Margenau-Hill quasiprobability (which is hence selected among other options). It coincides with the weak value of energy, and also with the hydrodynamic energy in the Madelung representation of quantum dynamics, which includes the quantum potential. Moreover, we find a new form of spin-related energy that is finite in the non-relativistic limit, emerges from the rest energy, and is (separately) locally conserved, though it does not contribute to the global energy budget. This form of energy has a holographic character, i.e., its value for a given volume is expressed via the surface of this volume. Our results apply to situations where local energy representation is essential; e.g. we show that the energy transfer velocity for a large class of free wave-packets (including Gaussian and Airy wave-packets) is larger than its group (i.e. coordinate-transfer) velocity.Comment: 9+6 pages, 3 figur

РЕАКЦИЯ ПРОМЫШЛЕННЫХ КОМПАНИЙ НА КРИЗИС: ИЗМЕНЕНИЕ БИЗНЕС-МОДЕЛИ И СТРАТЕГИЧЕСКАЯ УСТОЙЧИВОСТЬ

Nowadays the changes in the geopolitical situation significantly affect the conditions for doing business in Russia. The article reviews the peculiarities of the development of Russian industrial companies and the subsidiaries of foreign companies, operating in Russia, in difficult economic conditions. The contemporary consequences of global financial crisis of 2008 with respect to the industrial sector of the economy are also reviewed. The author performed an empirical study of the question of whether the companies' sustainable survival in 2014–2016 was affected by the change in the business model and whether these changes were caused by the experience of the previous crisis. The study considered the differences in the behavior of foreign and Russian companies, and the strategies, that reduce the risk of default, are defined.В настоящее время на условия ведения бизнеса в России существенно влияют изменения в геополитической ситуации. В статье исследуются особенности развития российских промышленных компаний и дочерних предприятий иностранных компаний, ведущих деятельность в России, в сложных экономических условиях. Также изучены современные последствия глобального финансового кризиса 2008 года в отношении промышленного сектора экономики. Проведено эмпирическое исследование вопроса о том, повлияло ли на устойчивое выживание компаний в 2014–2016 гг. изменение бизнес-модели и были ли данные изменения вызваны опытом предыдущего кризиса. Также рассмотрены различия в поведении российских компаний и компаний с участием иностранного капитала, определены стратегии, сокращающие риск дефолта

An improved neurogenetic model for recognition of 3D kinetic data of human extracted from the Vicon Robot system

في هذه الأيام ، انه من الضروري التمييز بين نوع السلوك البشري ، تلعب تقنيات الذكاء الاصطناعي دورًا كبيرًا في ذلك المجال. تم دمج خصائص خوارزمية الشبكة العصبية الاصطناعية (FANN) والخوارزمية الجينية لإنشاء آلية عمل مهمة تساعد في هذا المجال. حيث يمكن استخدام النظام المقترح للمهام الأساسية في الحياة ، مثل التحليل والأتمتة والتحكم والتعرف والمهام الأخرى. التقاطع والطفرة هما الآليتان الأساسيتان اللتان تستخدمهما الخوارزمية الجينية في النظام المقترح لاستبدال عملية الانتشار العكسي في ANN. بينما تركز تقنية الشبكة العصبية الاصطناعية المغذية على معالجة المدخلات ، يعتمد هذا العمل على عملية كسر خوارزمية الشبكة العصبية الاصطناعية المغذية. بالإضافة إلى ذلك ، يتم حساب النتيجة من كل ANN أثناء عملية التفكك ، والتي تعتمد على تقسيم خوارزمية الشبكة العصبية الاصطناعية إلى عدة شبكات ANN بناءً على عدد طبقات ANN ، وبالتالي ، كل طبقة في الشبكة العصبية الاصطناعية الأصلية يتم تقييمها. يتم اختيار أفضل الطبقات لمرحلة التقاطع بعد عملية الكسر ، بينما تمر الطبقات الأخرى بعملية الطفرة. ثم يتم تحديد مخرجات هذا الجيل من خلال دمج الشبكات العصبية الاصطناعية في شبكة ANN واحدة ؛ ثم يتم فحص النتيجة لمعرفة ما إذا كانت العملية تحتاج إلى إنشاء جيل جديد. ان أداء النظام جيدًا وأنتج نتائج دقيقة عند استخدامه مع البيانات المأخوذة من نظام Vicon Robot ، والذي تم تصميمه بشكل أساسي لتسجيل السلوكيات البشرية بناءً على بيانات ثلاثية الابعاد وتصنيفها على أنها طبيعية أو عدوانية.These days, it is crucial to discern between different types of human behavior, and artificial intelligence techniques play a big part in that.  The characteristics of the feedforward artificial neural network (FANN) algorithm and the genetic algorithm have been combined to create an important working mechanism that aids in this field. The proposed system can be used for essential tasks in life, such as analysis, automation, control, recognition, and other tasks. Crossover and mutation are the two primary mechanisms used by the genetic algorithm in the proposed system to replace the back propagation process in ANN. While the feedforward artificial neural network technique is focused on input processing, this should be based on the process of breaking the feedforward artificial neural network algorithm. Additionally, the result is computed from each ANN during the breaking up process, which is based on the breaking up of the artificial neural network algorithm into multiple ANNs based on the number of ANN layers, and therefore, each layer in the original artificial neural network algorithm is assessed. The best layers are chosen for the crossover phase after the breakage process, while the other layers go through the mutation process. The output of this generation is then determined by combining the artificial neural networks into a single ANN; the outcome is then checked to see if the process needs to create a new generation. The system performed well and produced accurate findings when it was used with data taken from the Vicon Robot system, which was primarily designed to record human behaviors based on three coordinates and classify them as either normal or aggressive

Photon cooling: linear vs nonlinear interactions

Linear optics imposes a relation that is more general than the second law of thermodynamics: For modes undergoing a linear evolution, the full mean occupation number (i.e. photon number for optical modes) does not decrease, provided that the evolution starts from a (generalized) diagonal state. This relation connects to noise-increasing (or heating), and is akin to the second law and holds for a wide set of initial states. Also, the Bose-entropy of modes increases, though this relation imposes additional limitations on the initial states and on linear evolution. We show that heating can be reversed via nonlinear interactions between the modes. They can cool -- i.e. decrease the full mean occupation number and the related noise -- an equilibrium system of modes provided that their frequencies are different. Such an effect cannot exist in energy cooling, where only a part of an equilibrium system is cooled. We describe the cooling set-up via both efficiency and coefficient of performance and relate the cooling effect to the Manley-Rowe theorem in nonlinear optics.Comment: 16 pages, 9 figures; second extended version to appear in Physical Review

Controlled Nanoparticle Formation by Diffusion Limited Coalescence

Polymeric nanoparticles (NPs) have a great application potential in science and technology. Their functionality strongly depends on their size. We present a theory for the size of NPs formed by precipitation of polymers into a bad solvent in the presence of a stabilizing surfactant. The analytical theory is based upon diffusion-limited coalescence kinetics of the polymers. Two relevant time scales, a mixing and a coalescence time, are identified and their ratio is shown to determine the final NP diameter. The size is found to scale in a universal manner and is predominantly sensitive to the mixing time and the polymer concentration if the surfactant concentration is sufficiently high. The model predictions are in good agreement with experimental data. Hence the theory provides a solid framework for tailoring nanoparticles with a priori determined size.Comment: 4 pages, 3 figure

The influence of motor activity on the development of cardiac arrhythmias during experimental emotional stress

Experimental emotional stress which can produce various disorders of cardiac rhythm: sinus tachycardia, atrial fibrillation, ventricular, extrasystoles and paroxysmal ventricular tachysystoles was studied. In these conditions the adrenalin content in the blood and myocardium is increased 3 to 4 times. It is found that moderate motor activity leads to a relative decrease of adrenalin in the myocardium and arrest of cardiac arrhythmias

A Selection Rule for Multiquark Decays

By assuming SU(6)_cs symmetry for pentaquark decays one finds a selection rule, which strongly reduces the number of states able to decay into a baryon and a meson final state and allows an intriguing identification for the Theta^+ particle recently discovered with the prediction of a narrow width.Comment: 10 pages, no figure

THE REACTION OF INDUSTRIAL COMPANIES TO CRISIS: CHANGES IN BUSINESS-MODEL AND STRATEGIC SUSTAINABILITY

Nowadays the changes in the geopolitical situation significantly affect the conditions for doing business in Russia. The article reviews the peculiarities of the development of Russian industrial companies and the subsidiaries of foreign companies, operating in Russia, in difficult economic conditions. The contemporary consequences of global financial crisis of 2008 with respect to the industrial sector of the economy are also reviewed. The author performed an empirical study of the question of whether the companies' sustainable survival in 2014–2016 was affected by the change in the business model and whether these changes were caused by the experience of the previous crisis. The study considered the differences in the behavior of foreign and Russian companies, and the strategies, that reduce the risk of default, are defined