SIXTH INTERNATIONAL CONFERENCE OF THE BALKAN PHYSICAL UNION

Superscaling analyses of inclusive electron scattering and their extension to charge‐changing neutrino cross sections in nuclei
View Description Hide DescriptionSuperscaling analyses of inclusive electron scattering from nuclei are extended from the quasielastic processes to the delta excitation region. The calculations of (e, e′) cross sections for the target nucleus ^{12}C at various incident electron energies are performed using scaling functions f(ψprime;) obtained in approaches going beyond the mean‐field approximation, such as the coherent density fluctuation model (CDFM) and the one based on the light‐front dynamics (LFD) method. The superscaling properties of the electron scattering are used to predict charge‐changing neutrino‐nucleus cross sections at energies from 1 to 2 GeV. The analyses make it possible to gain information about the nucleon correlation effects on both local density and nucleon momentum distributions.

Electromagnetic Moments of Exotic Nuclei: Recent Studies
View Description Hide DescriptionState‐of‐the‐art studies of electromagnetic moments of exotic nuclei in experiments with radioactive beams are presented. These include first results on the 19/2^{+} isomer in ^{127}Sn, which was populated in a relativistic fragmentation reaction within the g‐RISING campaign at GSI, Darmstadt, Germany, and the first measurement of a nuclear quadrupole moment of an isomeric state in fragmentation reaction, that of the 9/2^{+} isomer in ^{61}Fe, which was performed at GANIL, Caen, France. Results from experiments to measure the electromagnetic moments in transfer reactions are also discussed, as well as the perspectives to utilize this technique in experiments with post‐accelerated ISOL beams in inverse kinematics.

Quantum Phase Transitions in Finite Nuclei: Theoretical Concepts and Experimental Evidence
View Description Hide DescriptionThe concept of quantum phase transitions in the equilibrium structure of finite nuclei as a function of N and Z has recently taken on considerable interest. Sparked by data in nuclei with N=90, which pointed towards the presence of coexisting spherical and deformed phases, a new class of models for nuclei at the phase transitional point, called Critical Point Symmetries, was developed: E(5), for nuclei in a second order vibrator to γ‐soft rotor, and X(5) for nuclei in a first order vibrator to axially deformed rotor. Empirical examples of both symmetries were discovered, in ^{134}Ba and ^{152}Sm, respectively. Following this, a large body of research ensued, both theoretical and experimental, including new approaches to the mapping of structural evolution, new ideas about the relation of geometrical and algebraic models, about order and chaos in nuclear spectra, and about the relation of residual proton‐neutron interactions to the development of correlations in the nuclear many‐body system. Some of these developments will be discussed.

Saddle point shapes of nuclei
View Description Hide DescriptionVery general reflection asymmetrical saddle point nuclear shapes are obtained by solving an integro‐differential equation without being necessary to specify a certain parametrization. This equation is derived as an Euler‐Lagrange relationship associated to the variational problem of minimizing the potential energy with constraints (constant volume and given deformation parameter). The mass asymmetry in binary cold fission of Th and U isotopes is explained as the result of adding a phenomenological shell correction to the liquid drop model deformation energy. Applications to ternary fission are outlined.

First Results from the Stopped RISING Campaign at GSI: The Mapping of Isomeric Decays in Highly Exotic Nuclei
View Description Hide DescriptionThe first results from the Stopped Beam RISING experimental campaign performed at the GSI laboratory in Darmstadt, Germany, are presented. RISING (Rare ISotope INvestigations at GSI) constitutes a major new experimental program in European nuclear structure physics research aimed at using relativistic‐energy, projectile‐fragmentation reactions to study nuclei with exotic proton‐to‐neutron ratios. This paper introduces the physics aims of the Stopped RISING collaboration and presents some technical details and initial results from experiments using the RISING array to study decays from metastable nuclear states in both proton and neutron‐rich nuclei.

The Bucharest Tandem Accelerator — part of the European Infrastructure
View Description Hide DescriptionThe Bucharest Tandem van de Graaff accelerator in Bucharest is described. The scientific program in both applied and basic research is outlined. Through many international collaborations, the accelerator is, indeed, part of the European Nuclear Physics Research infrastructure.

Proton‐Neutron Correlation Energies From Self‐Consistent Large‐Scale Mass Calculations
View Description Hide DescriptionProton‐neutron correlation energies extracted from double differences in binding energies, obtained from theoretical masses calculated within the Skyrme density functional theory with contact pairing interaction, are compared with experimental values based on the 2003 nuclear mass compilation. It is shown that theory gives a qualitative (and often quantitative) reproduction of experiment. The agreement is particularly good for deformed nuclei. For transitional systems, the comparison suggests that more theoretical work is required to incorporate dynamic correlations that go beyond the mean‐field theory.

Finding the Axion: The Search for the Dark Matter of the Universe
View Description Hide DescriptionThe nature of dark matter has been a mystery for over 70 years. One plausible candidate is the axion, an extremely light and weakly interacting particle, which results from the Peccei‐Quinn solution to the strong CP problem. In this proceedings I will briefly review the evidence for dark matter as well as the motivation for the existence of the axion as a prime dark matter candidate. I will then discuss the experimental methods to search for axion dark matter focusing on a sensitive cavity experiment (ADMX) being run at Lawrence Livermore National Laboratory.

Coherent Atom Optics With Fast Metastable Beams: Metastable Helium Diffraction By 1D and 2D Magnetized Reflection Gratings
View Description Hide Description1D and 2D reflection gratings (Permalloy stripes or dots deposited on silicon), immersed in an external homogeneous static magnetic field, are used to study 1D and 2D diffraction of fast metastable helium atoms He* (2^{3}S_{1}). Both the grazing incidence used here and the repulsive potential (for sub‐level m = −1) generated by the magnetisation reduce the quenching effect. This periodically structured potential is responsible for the diffraction in the incidence plane as well as for the diffraction in the perpendicular plane.

CAST — A CERN Experiment to Search for Solar Axions
View Description Hide DescriptionThe CAST experiment at CERN is the only running solar axion telescope. The first results obtained so far with CAST — PHASE I is presented, which compete with the best astrophysically derived limits of the axion‐to‐photon coupling. The ongoing PHASE II of the experiment as well as the scheduled upgrades, which improve the axion discovery potential of CAST, are discussed.

The ATLAS Muon Spectrometer and the hunt for the Higgs Boson(s)
View Description Hide DescriptionThe Muon Spectrometer is an essential part of the ATLAS Detector at the LHC. It is used both for triggering and for momentum measurements of the muons. The four different technologies used for the Muon chambers as well as their expected performance are described. Furthermore, the ATLAS sensitivity for the SM and the MSSM Higgs bosons decaying into muons is reviewed. Emphasis is given in the expected discovery potentials from the first year of running.

Novel Ideas for Neutrino Beams
View Description Hide DescriptionRecent developments in neutrino physics, primarily the demonstration of neutrino oscillations in both atmospheric neutrinos and solar neutrinos, provide the first conclusive evidence for physics beyond the Standard Model of particle physics. The simplest phenomenology of neutrino oscillations, for three generations of neutrino, requires six parameters — two squared mass differences, 3 mixing angles and a complex phase that could, if not 0 or π, contribute to the otherwise unexplained baryon asymmetry observed in the universe. Exploring the neutrino sector will require very intense beams of neutrinos, and will need novel solutions.

Flavor Democracy in Particle Physics
View Description Hide DescriptionThe flavor democracy hypothesis (or, in other words, democratic mass matrix approach) was introduced in seventies taking in mind three Standard Model (SM) families. Later, this idea was disfavored by the large value of the t‐quark mass. In nineties the hypothesis was revisited assuming that extra SM families exist. According to flavor democracy the fourth SM family should exist and there are serious arguments disfavoring the fifth SM family. The fourth SM family quarks lead to essential enhancement of the Higgs boson production cross‐section at hadron colliders and the Tevatron can discover the Higgs boson before the LHC, if it mass is between 140 and 200 GeV. Then, one can handle “massless” Dirac neutrinos without see‐saw mechanism. Concerning BSM physics, flavor democracy leads to several consequences: tanβ ≈ m_{t}/m_{b} ≈ 40 if there are three MSSM families; super‐partner of the right‐handed neutrino can be the LSP; relatively light E(6)‐inspired isosinglet quark etc. Finally, flavor democracy may give opportunity to handle “massless” composite objects within preonic models.

Pentaheptide Alotropes Of Carbon Nanotubes
View Description Hide DescriptionStone‐Wales bond rotation transforms four adjacent graphene hexagons into a pentaheptide ornament consisting of two pentagons and two heptagons. There are two types of lattices of these ornaments, one hexagonal and the other one rectangular. We determine symmetry of arbitrary rolled up nanotubes of both types. This is used to relax the purely folded configurations for large number of tubes, and compare thei stability and electronic properties to the properties of the generic graphene single‐wall nanotubes. Density functional tight binding calculations are performed by the full‐symmetry implemented numerical code POLSym. Generally, pentaheptide tubes are less stable than the generic ones, and vast majority of them is conducting. For the particular tubes we predict transition from generic to the pentaheptide form by applying mechanical stress.

Vibronic Spectra of Mixed Frenkel and Charge‐Transfer Excitons
View Description Hide DescriptionThe excitonic and vibronic spectra of a molecular chain and of crystal of MePTCDI are studied in the case when: (i) a Frenkel exciton (FE) and charge transfer excitons (CTEs) mix strongly; (ii) two mechanisms of coupling between these mixed excitons and intramolecular vibrations, notably linear and quadratic coupling, are acting. Using a convenient canonical transformation and the Green function method, we calculate the linear optical susceptibility. The spectra of linear absorption in the excitonic and vibronic regions have been calculated introducing the exciton parameters of MePTCDI. These spectra exhibit: (i) a relative separation of vibronics of FE and CTEs and transfer of intensity from a FE to CTEs excitonic and vibronic lines; (ii) a stronger impact of the linear coupling on the intensity of the excitonic and vibronic spectra; (iii) the appearance of a spectral doublet of vibronics of the CTEs—its splitting depends on the parameters of linear and quadratic exciton‐phonon coupling in the neutral excited molecule and ions. Moreover, in the case of weak linear exciton‐phonon coupling the vibronic line of FE, being wide and flat, lies in two‐particle continuum while in the case of intermediate and strong linear coupling the linear absorption is dominated by the bound exciton‐phonon states and their narrow Lorentzian maxima depend strongly on the quadratic coupling.

Studies of Flow in Ionized Gas: Historical Perspective, Contemporary Experiments, and Applications
View Description Hide DescriptionSince the first observations that a very small ionized fraction (order of 1 ppm) could strongly affect the gas flow, numerous experiments with partially or fully wall‐free discharges have demonstrated the dispersion of shock waves, the enhancement of lateral forces in the flow, the prospects of levitation, and other aerodynamic effects with vast potential of application. A review of physical effects and observations are given along with current status of their interpretation. Special attention will be given to the physical problems of energy efficiency in generating wall‐free discharges and the phenomenology of filamentary discharges. Comments and case examples are given on the current status of availability of necessary data for modelling and simulation of the aerodynamic phenomena in weakly ionized gas.

New Developments in Quantum Mechanics and Applications
View Description Hide DescriptionThe analytical relation is suggested for the centrally symmetric potential which contains the core attraction potential and the potential of the field produced by the particle itself. The eigenfunctions corresponding to this potential are complete without the inclusion of the continuum states. The group of transformations of eigenfunctions and total centrally symmetric potential presented in this work is the four‐dimensional rotation group O(4).

Topology of the potential energy surface and the origin of phase changes in finite atomic clusters
View Description Hide DescriptionThe important differences between the behavior of bulk matter and small systems with respect to their phases and phase changes keep the interest in the subject vivid. On the other hand, small systems display forms that have properties very similar to those we associate with specific phases of bulk matter. Thus various theoretical approaches are needed to understand both similarities and differences. One way is to study the topology of the configuration space of a small system, like atomic clusters, through the critical points of the multidimensional potential energy surface generated by bound model potentials. The dynamics of the system can be linked to the topology by master equations: a phase transition occurs if the topology of the configuration space of a cluster changes. The effective order of phase changes of small systems can be related directly to what kind of symmetry change occurs at the phase change.

On Quantum Decoherence
View Description Hide DescriptionFundamental as well as applied science appear substantially to depend on certain progress in the foundations of quantum mechanics, and particularly on the so‐called decoherence theory. Here, I present some new results on the foundations of the decoherence theory as well as a rather wide interest in this concern in the different fields of extensive scientific research (e.g. in modern physics, theory of macromolecules, modern technology, quantum information and computation theory).