

Physics of Elementary Particles and Atomic Nuclei

Archive (1970  2015)  Editorial board  Guidance for Authors 
Part 1  up 
Adamian G.G., Antonenko N.V., Kalandarov Sh.A. Description of the Quasifission Reactions in the Framework of Dinuclear System Model (rus, 1.8 Mb) Formation and evolution of dinuclear system in quasifission reactions are considered. In the framework of dinuclear system concept the processes of formation of reaction products are investigated. Isotopic dependence of formation cross sections of superheavy nuclei in quasifission reactions is considered. The yields of new neutronrich isotopes of nuclei with Z = 64  80 in quasifission reactions are predicted. The mechanism of complex fragment formation in complete fusion and quasifission reactions is analyzed. 

Artukh A.G., Klygin S.A., Kononenko G.A., Kyslukha D.A., Lukyanov S.M., Mikhailova T.I., Oganessian Yu.Ts., Penionzhkevich Yu.E., Sereda Yu.M., Vorontsov A.N., Erdemchimeg B. Radioactive Nuclear Beams of COMBAS Facility (eng, 1.2 Mb) The basic ionoptical characteristics of the highluminosity and highresolution kinematic separator COMBAS, realized for the first time on the strong focusing principle, are presented. The developed facility allows one to separate the highintensity secondary radioactive beams in a wide range of mass numbers A and atomic numbers Z, which are produced in heavyion reactions in the energy range of 20 E 100 MeV/A (Fermi energy domain). Two distinct detector systems, such as realized Si stripdetector telescope and the threedimensional timeprojection chamber of promising development, are discussed. A program of the investigations of nuclear reaction mechanisms at intermediate energies of 20100 MeV/A, measurement of the radii of unstable nuclei, study of the cluster structure of light nuclei near the nuclear dripline, and search for ^{26,28}Î resonances in exchange reactions is proposed. The upgrading of experimental facility by the integration of COMBAS separator with the ion catcher is discussed. 

Tsyganov Yu.S. Experiment Automation at the Dubna GasFilled Recoil Separator (rus, 3.3 Mb) Different approaches to solving tasks related to the automation of main processes in longterm experiments with heavyion beams at the Dubna gasfilled recoil separator (DGFRS) are examined. Techniques in the field of spectroscopy of rare decays of superheavy nuclei and approaches to the development of control systems which ensure failsafety when conducting experiments with extremely radioactive targets and registration of the main parameters of experiments are described. The specificity of DSSSD (Double Side Silicon Strip Detector) detectors is examined. A special emphasis is placed on the role of edge phenomena of neighboring pn junctions when the method for "active correlations" is applied. An example of a beamfree experiment is briefly examined in an attempt to observe the Zeno effect. The main examples are specified for nuclear complete fusion reactions with beams of ^{48}Ca accelerated by the U400 cyclotron at FLNR, JINR. 

Zalikhanov B.Zh. From the Electron Avalanche to Lightning Discharge (rus, 650 Kb) The work gives a qualitative description of the physics of the processes beginning with an electron avalanche and ending with a lightning discharge. A streamer model is considered that is based on the investigation of the observed new processes occurring in the prestreamer region. The study and analysis of these processes allow a conclusion that they are actually accompanying processes to support transition of an electron avalanche to a streamer and can be interpreted as a manifestation of the properties of the double charge layer in an external electric field. Important problems of physical processes underlying formation of a lightning discharge are considered on the basis of the new concept of streamer formation and intergrowth. Causes for coherent microwave leader radiation and neutron generation in a lightning discharge that have not yet been explained in the gas discharge theory are disclosed. A simple globe lightning model is also proposed on the basis of the new concept, which allows answering all questions arising from the observation of the globe lightning behavior, and a necessity of changing over from the traditional lightning rod to a lightning guard of a new design is discussed. 

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Part 2  up 
Rodionov V.N., Kravtsova G.A. Algebraic PTSymmetric Quantum Theory with a Maximal Mass (rus, 400 Êb) In this article we want to draw attention to the fact that the approaches developed by V.G.Kadyshevsky in the course of several decades and devoted to the geometric construction of quantum field theory with fundamental mass containing nonHermitian mass extensions have recently gained a powerful development in the form of construction of the nonHermitian algebraic approach. The central point of these theories is the construction of new scalar products in which the average values of nonHermitian Hamiltonians are valid. Among numerous works on this subject there are both purely mathematical and containing a discussion of experimental results. In this regard, we consider the development of algebraic relativistic pseudoHermitian quantum theory with a maximal mass and discuss its experimentally significant consequences. 

Sargsyan V.V., Kanokov Z., Adamian G.G., Antonenko N.V. Application of the Theory of Open Quantum Systems in Nuclear Physics (rus, 3550 Êb) Quantum diffusion equations with transport coefficients, explicitly depending on time, are derived from the generalized nonMarkovian Langevin equations. The asymptotic behavior of the friction and diffusion coefficients is studied in the cases of FC and RWAcouplings between the collective and internal subsystems. The asymptotics of the propagator of the density matrix of open quantum system is obtained in the general case of quadratic Hamiltonian linearly coupled (in coordinate and momentum) with internal degrees of freedom. The influence of different sets of transport coefficients on decoherence and decay rate of the metastable state is studied by using the master equation for the reduced density matrix of open quantum systems. The developed approach is used to study the capture of the projectile by the target nucleus at energies near the Coulomb barrier. With the calculated capture probabilities, a good agreement between the calculated capture cross sections and experimental data is obtained. Specific cases where the dissipation promotes penetration through the potential barrier are revealed. The analytical derivation of the generalized Kramers formula is presented for the quasistationary decay rate of quantum metastable systems. 

Kuklin S.N., Adamian G.G., Antonenko N.V. Description of Alpha Decay and Cluster Radioactivity in the Dinuclear System Model (rus, 500 Êb) The description of the cluster radioactivity and decay of the cold nuclei is suggested in the dinuclear system model. The quantum fluctuation of the dynamic coordinate in the charge (mass) asymmetry determines the value of spectroscopic factor, and tunneling in the coordinate relative distance determines the amount of the barrier penetrability of the nucleusnucleus interaction potential. A new method of calculation of the spectroscopic factor is suggested. The hindrance factors for the transfer of orbital angular momentum are studied. For decays of neutrondeficient nuclei ^{194,196}Rn, we give the possible explanation of the deviations of the halflives from the GeigerNuttall law. The fine structure of decays of isotopes of U and Th is described and predicted. The model is employed to describe the decay from the states of the rotational band of the eveneven nuclei. For the regions of "lead" and "tin" cluster radioactivities, the halflives are well described and the most probable cluster yields are predicted. The cluster decay from the excited nuclei is considered. The connection of cluster radioactivity with spontaneous fission as well as with highly deformed nuclear states is discussed. 

Logachev P.V., Meshkov O.I., Starostenko A.A., Nikiforov D.A., Andrianov A.V., Maltseva Yu.I., Levichev A.E., Emanov F.A. NonDestructive Diagnostic Methods for the Charged Particle Beams (rus, 2025 Êb) The article provides an overview of the main methods of the nondestructive diagnostic and losses registration of the charged particle beams used in the accelerator technology. It can help to choose diagnostic and beam loss registration systems, and gives the qualitative understanding of the devices operation principles. Quantitative characteristics are presented for each type of diagnostic to define the boundaries of the application. 

Gongadze A.L. Micromegas Chambers for the Experiment ATLAS at the LHC (rus, 2007 Êb) The increase in luminosity and energy of the LHC in the next upgrade (Phase1) in 20182019 will lead to a significant increase in radiation load on the ATLAS detector, primarily in the areas close to the interaction point of the LHC proton beams. One of these regions is the Small Wheel of the ATLAS Muon Spectrometer. It is planned to replace it with the New Small Wheel that will have Micromegas chambers as main coordinate detectors. The paper gives an overview of all existing types of Micromegas detectors with special focus on the Micromegas chambers for the ATLAS detector upgrade. 

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Part 3  up 
Buchbinder I.L., Ivanov E.A., Pletnev N.G. Superfield Approach to Construction of the Effective Action in Quantum Field Theory with Extended Supersymmetry (rus, 1.1 Ìb) This is a review of the modern status of research on construction of the effective actions in supersymmetric quantum field theory. A special attention is paid to gauge models with extended supersymmetry in the superfield approach. The advantages of formulating such models in N=2 harmonic superspace are emphasized. We describe the manifestly supersymmetric and manifestly covariant methods of constructing the lowenergy effective actions, deriving the corrections to them and obtaining the exact results. We consider in detail the calculations of the oneloop effective actions in N=2 supersymmetric YangMills theories coupled to hypermultiplets and in N=4 supersymmetric YangMills theory. The relationship between the effective action in supersymmetric quantum field theory and the lowenergy limits of the superstring theory is discussed. 

Dorokhov A.E., Radzhabov A.E., Shamakhov F.A., Zhevlakov A.S. The Nonlocal Chiral Quark Model and the Muon g2 Problem (eng, 390 Êb) In the first part of the review we discuss the effective nonlocal approach in the quantum field theory. It concerns primarily the historical retrospective of this approach, and then we concentrate on the interaction of matter particles (fermions and bosons) with the (Abelian and nonAbelian) gauge fields. In the second part of the review we consider the hadronic corrections (vacuum polarization) to the anomalous magnetic moment of the muon g2 factor discussed within the SU_{f}(2) nonlocal chiral quark model. This is considered in the leading and, partially, in the nexttoleading orders (the effect of the fermion propagator dressing due to pion field) of expansion in small parameter 1/N_{c} (N_{c} is the number of colors in QCD). 

Adamian G.G., Antonenko N.V., Bezbakh A.N., Jolos R.V. Influence of Properties of Superheavy Nuclei on Their Formation and Decay (rus, 2.1 Mb) Properties and stability are discussed for superheavy nuclei obtained in hot fusion reactions. As shown, the microscopicmacroscopic approach can result in the proton shell closure at Z120. The isotopic trends of K isomers are predicted in superheavy nuclei. The evaporation residue cross sections in hot fusion reactions are calculated with the predicted properties of superheavies. The interruption of decay chain by spontaneous fission is analyzed. Alphadecay chains over the isomeric states are considered. The internal level densities are microscopically calculated in superheavy nuclei. 

Titov A.I., Kampfer B., Hosaka A., Takabe Hideaki Quantum Processes in Short and Intensive Electromagnetic Fields (eng, 940 Êb) This work provides an overview of our recent results in studying two most important and widely discussed quantum processes: electronpositron pair production off a probe photon propagating through a polarized shortpulsed electromagnetic (e.g., laser) wave field or generalized BreitWheeler process, and a single photon emission off an electron interacting with the laser pulse, the socalled nonlinear Compton scattering. We show that the probabilities of particle production in both the processes are determined by interplay of two dynamical effects, where the first one is related to the shape and duration of the pulse, and the second one is nonlinear dynamics of the interaction of charged fermions with a strong electromagnetic field. We elaborate suitable expressions for the production probabilities and cross sections, convenient for studying evolution of the plasma in presence of strong electromagnetic fields. 

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Joint Institute for Nuclear Research  60 (rus, 40 Êb) 

Volkov M.K., Arbuzov A.B. LowEnergy Processes of Meson Production in the Extended NambuJonaLasinio Model (rus, 370 Êb) In the framework of the extended NambuJonaLasinio model, lowenergy processes of meson production in electronpositron collisions are described. It is shown that in these processes intermediate vector mesons, both in the ground and in the first radialexcited states, play an important role. Our results are in satisfactory agreement with the existing experimental data. A set of theoretical predictions, which can be tested experimentally in the nearest future, is given. 

Ivanov E.A. Gauge Fields, Nonlinear Realizations, Supersymmetry (eng, 480 Kb) This is a brief survey of the allyears research activity in the Sector "Supersymmetry" (the former Markov Group) at the Bogoliubov Laboratory of Theoretical Physics. The focus is on the issues related to gauge fields, spontaneously broken symmetries in the nonlinear realizations approach, and diverse aspects of supersymmetry. 

Batyuk P.N., Kekelidze V.D., Kolesnikov V.I., Rogachevsky O.V., Sorin A.S., Voronyuk V.V. (on behalf of the BM@N and MPD collaborations) Feasibility Study of Heavy Ion Physics Program at NICA (eng, 2.0 Mb) There is strong experimental and theoretical evidence that in collisions of heavy ions at relativistic energies the nuclear matter undergoes a phase transition to the deconfined state  QuarkGluon Plasma. The caused energy region of such a transition was not found at high energy at SPS and RHIC, and search for this energy is shifted to lower energies, which will be covered by the future NICA (Dubna), FAIR (Darmstadt) facilities and BES II at RHIC. Fixed target and collider experiments at the NICA facility will work in the energy range from a few AGeV up to = 11 GeV and will study the most interesting area on the nuclear matter phase diagram. The most remarkable results were observed in the study of collective phenomena occurring in the early stage of nuclear collisions. Investigation of the collective flow will provide information on Equation of State (EoS) for nuclear matter. Study of the eventbyevent fluctuations and correlations can give us signals of critical behavior of the system. Femtoscopy analysis provides the spacetime history of the collisions. Also, it was found that baryon stopping power revealing itself as a "wiggle" in the excitation function of curvature of the (net) proton rapidity spectrum relates to the order of the phase transition. The available observations of an enhancement of dilepton rates at low invariant masses may serve as a signal of the chiral symmetry restoration in hot and dense matter. Due to this fact, measurements of the dilepton spectra are considered to be an important part of the NICA physics program. The study of strange particles and hypernuclei production gives additional information on the EoS and "strange" axis of the QCD phase diagram. In this paper a feasibility of the considered investigations is shown by the detailed Monte Carlo simulations applied to the planned experiments (BM@N, MPD) at NICA. 

Ceccucci A., Goudzovski E., Kekelidze V., Madigozhin D., Potrebenikov I. Kaon Decay Studies at CERN SPS in the Last Decades (eng, 875 Êb) This review summarizes the kaon experimental results obtained in the last 15 years on the basis of data collected at the CERN SPS with the participation of JINR physicists. These results contribute essentially to the Standard Model checks and search for its extension, fundamental symmetry violations and lowenergy strong interactions theory development. A progress in the experimental technique and prospects for the future results are also discussed. 

Filchenkov V.V. Physical Applications of Muon Catalysis, Muon Capture in Hydrogen (rus, 1.1 Ìb) The results of theoretical and experimental work on the capture of negative muons in hydrogen are presented. The accompanying phenomenon of muon catalysis in hydrogen and the features of the experimental method are particularly noted. The conclusion is made about the importance of determining the precise capture rate for the clarification of the Standard Model. 

Aksenov V.L., Balagurov A.M., Kozlenko D.P. Condensed Matter Research at the Modernized IBR2 Reactor: From Functional Materials to Nanobiotechnologies (rus, 1.6 Ìb) A review of the main research directions of the condensed matter realized at the IBR2 high flux pulsed reactor is presented. It is demonstrated that the spectrometer complex of the modernized reactor has a large potential for studies of the structural, magnetic and dynamical properties of novel functional materials and nanobiosystems, ensuring the leading JINR positions in neutron scattering studies of condensed matter in the longterm prospect. 

Frank A.I. Ultracold Neutrons and Interaction of Waves with Moving Matter (rus, 750 Kb) This review is devoted to the problem of interaction of neutron waves with moving matter. The validity of the 1/v law for ultracold neutrons and the possibility of representing neutron interaction with matter by means of the effective potential were tested in the experiments named "Null Fizeau experiment". In such experiments a neutron wave passes through a flat sample moving parallel to its border. Observation of any physical effects caused by such movement is the evidence of the fact that the concept of the constant effective potential is not correct. In the second part of the review we describe the prediction and the first observation of the Accelerated Matter Effect, which consists in the change of neutron energy after passing through the refractive sample moving with acceleration directed along or against the direction of neutron propagation. The characteristic features of this phenomenon in the case of doubly refractive matter are considered. In conclusion, the problem of propagation of neutron waves in matter moving with giant acceleration is discussed. 

Manoshin S.A., Belushkin A.V., Ioffe A.I. Development of Simulation Methods of Neutron Spectrometers and Virtual Neutron Scattering Experiments (rus, 435 Kb) In this review we present some results of modeling of the polarized neutron scattering instruments, using developed by the authors' components of the MonteCarlo based VITESS simulation package. The work was performed within the framework of collaboration between the Frank Laboratory of Neutron Physics JINR and the Juelich Center of Neutron Science (Forschungszentrum Juelich, Germany). Successful VITESS simulations were carried out for resonance and adiabatic gradient spin flippers, Drabkin resonator, classical spinecho spectrometer, resonance spinecho spectrometer, spinecho diffractometer for small angle neutron scattering, spinecho spectrometer with the rotating magnetic fields. Special efforts were undertaken to introduce in the VITESS the possibility to load the magnetic field 3dimensional space map from an external source (file), obtained by direct measurements or calculated by dedicated final elements calculations. A very good agreement of neutron polarimetric experiments with the VITESS calculations is demonstrated. 

Gundorin N.A., Zeinalov Sh.S., Kopatch Yu.N., Popov A.B., Furman W.I. Investigations of Fission Properties and Correlation Effects in Fission (rus, 1.4 Mb) This review presents the results of a study on the Peven and Podd angular correlations of fission fragments from ($n,f$)reaction on ^{235}U and ^{239}Pu target nuclei induced by unpolarized and polarized resonance neutrons, as well the TRI and ROTeffects in the ternary and binary fission of actinides caused by polarized thermal neutrons. The results of measurements of the prompt and delayed neutron yields per fission are presented too. The experimental data are analyzed on the basis of a new theoretical approach developed recently by JINRRNC Kurchatov Institute collaboration, which allowed to explain consistently the reduction of the multidimensional phase space fission fragments in space J^{}Kchannels and to identify the role of interresonance interference in the observed correlation effects. 

Kulikov S.A., Prikhodko V.I. A New Generation of Data Acquisition and Accumulation Systems of the Spectrometers' Complex at the IBR2 Reactor (rus, 961 Kb) The paper presents an overview of works on the creation of data acquisition and accumulation systems, which have been carried out in the Department of the IBR2 spectrometers' complex over the past 15 years (before, during and after the modernization of the IBR2 reactor). These systems represent a unified set of identical (from the viewpoint of hardware) modules limited in type but functionally complete, wherein distinctions in parameters, functional capabilities, encoding, correction and preliminary data processing procedures specific to each spectrometer are realized on the level of microprograms, electronic tables, and unified control software complex. 

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V. A. Matveev
V. L. Aksenov, Nguen Van Hieu
A. B. Arbuzov,
V. A. Bednyakov,
V. V. Burov,
M. A. Vasiliev,
V. V. Voronov,
R. V. Jolos,
P. I. Zarubin,
G. M. Zinovjev,
A. P. Isaev (Secretary),
E. A. Krasavin,
N. V. Krasnikov,
O. N. Krokhin,
R. Lednicky,
E. V. Lychagin,
I. N. Meshkov,
D. Nagy,
Yu. Ts. Oganessian,
A. G. Popeko,
A. A. Starobinskii,
Ch. Stoyanov,
Gh. Stratan,
G. V. Trubnikov,
V. I. Yukalov
G. V. Fedorova
Tel.:
(49621) 62650
FAX: +7(49621)65892
Email: pepan@jinr.ru
G. I. Smirnov