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Sample records for deformed e-e nuclei

  1. Neutron halo in deformed nuclei

    SciTech Connect

    Zhou Shangui; Meng Jie; Ring, P.; Zhao Enguang

    2010-07-15

    Halo phenomena in deformed nuclei are investigated within a deformed relativistic Hartree Bogoliubov (DRHB) theory. These weakly bound quantum systems present interesting examples for the study of the interdependence between the deformation of the core and the particles in the halo. Contributions of the halo, deformation effects, and large spatial extensions of these systems are described in a fully self-consistent way by the DRHB equations in a spherical Woods-Saxon basis with the proper asymptotic behavior at a large distance from the nuclear center. Magnesium and neon isotopes are studied and detailed results are presented for the deformed neutron-rich and weakly bound nucleus {sup 44}Mg. The core of this nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the occurrence of this decoupling effects are discussed.

  2. Clusterization and quadrupole deformation in nuclei

    SciTech Connect

    Cseh, J.; Algora, A.; Antonenko, N. V.; Jolos, R. V.; Scheid, W.; Darai, J.; Hess, P. O.

    2006-04-26

    We study the interrelation of the clusterization and quadrupole deformation of atomic nuclei, by applying cluster models. Both the energetic stability and the exclusion principle is investigated. Special attention is paid to the relative orientations of deformed clusters.

  3. Precision investigations of nuclei and nucleons with the (e, e'. gamma. ) reaction

    SciTech Connect

    Papanicolas, C.N.; Ammons, E.A.; Cardman, L.S.; Deininger, J.R.; Dolfini, S.M.; Mandeville, J.B.; Mueller, P.E.; Williamson, S.E.

    1988-11-20

    Recent theoretical and experimental investigations of the (e, e'..gamma..) reaction show that it provides a probe of unparalleled precision and selectivity. Experiments aimed towards the isolation of multipole form factors in mixed transitions, the study of continuum excitations in nuclei, and the measurement of the response of the proton are underway at several laboratories.

  4. Identical'' bands in normally-deformed nuclei

    SciTech Connect

    Garrett, J.D.; Baktash, C. ); Yu, C.H. . Dept. of Physics and Astronomy)

    1990-01-01

    Gamma-ray transitions energies in neighboring odd- and even-mass nuclei for normally-deformed nuclear configurations are analyzed in a manner similar to recent analyses for superdeformed states. The moment of inertia is shown to depend on pair correlations and the aligned angular momentum of the odd nucleon. The implications of this analysis for identical'' super-deformed bands are discussed. 26 refs., 9 figs.

  5. Monopole Strength Function of Deformed Superfluid Nuclei

    SciTech Connect

    Stoitsov, M. V.; Kortelainen, E. M.; Nakatsukasa, T.; Losa, C.; Nazarewicz, Witold

    2011-01-01

    We present an efficient method for calculating strength functions using the finite amplitude method (FAM) for deformed superfluid heavy nuclei within the framework of the nuclear density functional theory. We demonstrate that FAM reproduces strength functions obtained with the fully self-consistent quasi-particle random-phase approximation (QRPA) at a fraction of computational cost. As a demonstration, we compute the isoscalar and isovector monopole strength for strongly deformed configurations in ^{240}Pu by considering huge quasi-particle QRPA spaces. Our approach to FAM, based on Broyden's iterative procedure, opens the possibility for large-scale calculations of strength distributions in well-bound and weakly bound nuclei across the nuclear landscape.

  6. Few-nucleon transfer reactions on deformed nuclei

    SciTech Connect

    van den Berg, A.M.

    1985-01-01

    Recent developments discussed include: alpha-transfer reactions on deformed nuclei, quasi-elastic neutron transfer reactions induced by /sup 58/Ni beams on spherical and deformed samarium nuclei, and the population of low-lying states in neutron rich nuclei using (particle,..gamma..) or (particle,e) coincidence methods. 37 refs., 10 figs. (LEW)

  7. Effective field theory for deformed atomic nuclei

    SciTech Connect

    Papenbrock, Thomas F.; Weidenmüller, H. A.

    2016-04-13

    In this paper, we present an effective field theory (EFT) for a model-independent description of deformed atomic nuclei. In leading order this approach recovers the well-known results from the collective model by Bohr and Mottelson. When higher-order corrections are computed, the EFT accounts for finer details such as the variation of the moment of inertia with the band head and the small magnitudes of interband E2 transitions. Finally, for rotational bands with a finite spin of the band head, the EFT is equivalent to the theory of a charged particle on the sphere subject to a magnetic monopole field.

  8. Effective field theory for deformed atomic nuclei

    SciTech Connect

    Papenbrock, Thomas F.; Weidenmüller, H. A.

    2016-04-13

    In this paper, we present an effective field theory (EFT) for a model-independent description of deformed atomic nuclei. In leading order this approach recovers the well-known results from the collective model by Bohr and Mottelson. When higher-order corrections are computed, the EFT accounts for finer details such as the variation of the moment of inertia with the band head and the small magnitudes of interband E2 transitions. Finally, for rotational bands with a finite spin of the band head, the EFT is equivalent to the theory of a charged particle on the sphere subject to a magnetic monopole field.

  9. Effective field theory for deformed atomic nuclei

    NASA Astrophysics Data System (ADS)

    Papenbrock, T.; Weidenmüller, H. A.

    2016-05-01

    We present an effective field theory (EFT) for a model-independent description of deformed atomic nuclei. In leading order this approach recovers the well-known results from the collective model by Bohr and Mottelson. When higher-order corrections are computed, the EFT accounts for finer details such as the variation of the moment of inertia with the band head and the small magnitudes of interband E2 transitions. For rotational bands with a finite spin of the band head, the EFT is equivalent to the theory of a charged particle on the sphere subject to a magnetic monopole field.

  10. Deformed halo nuclei probed by breakup reactions

    NASA Astrophysics Data System (ADS)

    Nakamura, Takashi

    2013-07-01

    Breakup reactions play important roles in elucidating the structures near the drip lines, such as nuclear halo. The recent experimental results using the Coulomb and nuclear breakup reactions for the neutron-drip-line nuclei at the new-generation RI beam facility, RIBF at RIKEN, are presented. Focuses are put on the results on the newly found halo nucleus 31Ne, which is intriguing also in that this nucleus is in the island-of-inversion and thus could be strongly deformed. The results on other Ne/Mg/Si neutron rich isotopes ranging from N=20 towards N=28 are also briefly reported. The first breakup experiments using SAMURAI facility at RIBF and future perspectives are also presented.

  11. Mass extrapolations in the region of deformed rare Earth nuclei

    SciTech Connect

    Borcea, C.; Audi, G.

    1998-12-21

    A procedure based on the regularity property of the mass surface is proposed to make predictions for the masses of neutron rich deformed nuclei in the rare earth region. Tables are given for the estimated masses; they extend up to the presumed limit of the deformation region.

  12. CORE RECONSTITUTION IN HEAVY DEFORMED NUCLEI

    DTIC Science & Technology

    The deviations are enumerated in the smooth systematics of rotational and vibrational characteristics in the regions of the nuclear periodic table where...there is a considerable prolate deformation. These deviations are classified according to their position in the nuclear periodic table . A

  13. Recent Studies Of Correlations In Nuclei Using (e,e'p) Reactions

    SciTech Connect

    Gilad, Shalev; Monaghan, Peter

    2008-10-13

    New measurements of the reaction {sup 12}C(e,e'p) at high missing energies and momenta, at Q{sup 2} = 2(GeV/c){sup 2}, and at x{sub B}>1 are described. Preliminary cross sections for a large range of missing energies and momenta are presented and display a relation between the missing energies and momenta which takes into account the recoil and excitation of the residual nucleus. Distorted spectral functions were extracted. They display badly-broken factorization and raise doubt about knowledge of the elementary off-shell electron-nucleon cross sections for x{sub B}>1.

  14. Quasifree (e,e'p) Reactions and Proton Propagation in Nuclei

    SciTech Connect

    David Abbott; A. Ahmidouch; Ts.A. Amatuni; C. Armstrong; J. Arrington; J.A. Assamagan; K. Bailey; O.K. Baker; S. Barrow; K. Beard; D. Beatty; S. Beedoe; E. Beise; E. Belz; C. Bochna; H. Breuer; E.E.W. Bruins; R. Carlini; J. Cha; N. Chant; C. Cothran; W.J. Cummings; S. Danagoulian; D. Day; D. Deschepper; J.-E. Ducret; F. Duncan; J. Dunne; D. Dutta; T. Eden; R. Ent; H.T. Fortune; V. Frolov; D.F. Geesaman; H. Gao; R. Gilman; P. Gueye; J.O. Hansen; W. Hinton; R.J. Holt; C. Jackson; H.E. Jackson; C.E. Jones; S. Kaufman; J.J. Kelly; C. Keppel; M. Khandaker; W. Kim; E. Kinney; A. Klein; D. Koltenuk; L. Kramer; W. Lorenzon; K. McFarlane; D.J. Mack; R. Madey; P. Markowitz; J. Martin; A. Mateos; D. Meekins; M.A. Miller; R. Milner; J. Mitchell; R. Mohring; H. Mkrtchyan; A.M. Nathan; G. Niculescu; I. Niculescu; T.G. O'Neill; D. Potterveld; J.W. Price; J. Reinhold; C. Salgado; J.P. Schiffer; R.E. Segel; P. Stoler; R. Suleiman; V. Tadvosyan; L. Tang; B. Terburg; D. van Westrum; Pat Welch; C. Williamson; S. Wood; C. Yan; Jae-Choon Yang; J. Yu; B Zeidman; W. Zhao; B. Zihlmann

    1998-06-01

    The (e,e'p) reaction was studies on targets of C, Fe, and Au at momentum transfers squared Q{sup 2} of 0.6, 1.3, 1.8 and 3.3 GeV{sup 2} in a region of kinematics dominated by quasifree electron-proton scattering. Missing energy and missing momentum distributions are reasonably well described by plane wave impulse approximation calculations with Q{sup 2} and A dependent corrections that measure the attenuation of the final state protons.

  15. E2 transitions in deformed nuclei and the IBA

    SciTech Connect

    Warner, D.D.; Casten, R.F.

    1981-01-01

    The mechanism which determines the relative E2 strengths in the Interacting Boson Approximation is studied, and the structure of the E2 operator necessary to reproduce the empirical B(E2) values in deformed even-even nuclei in the rate earth region is investigated. (WHK)

  16. Modeling level structures of odd-odd deformed nuclei

    SciTech Connect

    Hoff, R.W.; Kern, J.; Piepenbring, R.; Boisson, J.P.

    1985-01-15

    A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei has been applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation were derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings were used. Calculated and experimental level structures for /sup 238/Np, /sup 244/Am, and /sup 250/Bk are compared, as well as those for several nuclei in the rare-earch region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Corresponding average deviations for five rare-earth nuclei are 47 keV and 7%. Several applications of this modeling technique are discussed.

  17. Modeling level structures of odd-odd deformed nuclei

    SciTech Connect

    Hoff, R.W.; Kern, J.; Piepenbring, R.; Boisson, J.P.

    1984-09-07

    A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei has been applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation were derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings were used. Calculated and experimental level structures for /sup 238/Np, /sup 244/Am, and /sup 250/Bk are compared, as well as those for several nuclei in the rare-earth region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Corresponding average deviations for five rare-earth nuclei are 47 keV and 7%. Several applications of this modeling technique are discussed. 18 refs., 5 figs., 4 tabs.

  18. Assigning {gamma} deformation from fine structure in exotic nuclei

    SciTech Connect

    Ferreira, L. S.; Maglione, E.; Arumugam, P.

    2011-10-28

    The nonadiabatic quasiparticle model for triaxial shapes is used to perform calculations for decay of {sup 141}Ho, the only known odd-Z even-N deformed nucleus for which fine structure in proton emission from both ground and isomeric states has been observed. All experimental data corresponding to this unique case namely, the rotational spectra of parent and daughter nuclei, decay widths and branching ratios for ground and isomeric states, could be well explained with a strong triaxial deformation {gamma}{approx}20. The recent experimental observation of fine structure decay from the isomeric state, can be explained only with an assignment of I{sup {pi}} = 3/2{sup +} as the decaying state, in contradiction with the previous assignment, of I{sup {pi}} 1/2{sup +}, based on adiabatic calculations. This study reveals that proton emission measurements could be a precise tool to probe triaxial deformations and other structural properties of exotic nuclei beyond the proton dripline.

  19. Proton propagation in nuclei studied in the ( e , e prime p ) reaction

    SciTech Connect

    Garino, G.; Saber, M.; Segel, R.E. ); Geesaman, D.F.; Gilman, R.; Green, M.C.; Holt, R.J.; Schiffer, J.P.; Zeidman, B. ); Beise, E.J.; Dodson, G.W.; Hoibraten, S.; Pham, L.D.; Redwine, R.P.; Sapp, W.W.; Williamson, C.F.; Wood, S.A. ); Chant, N.S.; Roos, P.G. ); Silk, J.D. ); Deady, M. ); Maruyama, X.K. )

    1992-02-01

    Proton propagation in nuclei was studied using the ({ital e},{ital e}{prime}{ital p}) reaction in the quasifree region. The coincidence ({ital e},{ital e}{prime}{ital p}) cross sections were measured at an electron angle of 50.4{degree} and proton angles of 50.1{degree}, 58.2{degree}, 67.9{degree}, and 72.9{degree} for {sup 12}C, {sup 27}Al, {sup 58}Ni, and {sup 181}Ta targets at a beam energy of 779.5 MeV. The average outgoing proton energy was 180 MeV. The ratio of the ({ital e},{ital e}{prime}{ital p}) yield to the simultaneously measured ({ital e},{ital e}{prime}) yield was compared to that calculated in the plane-wave impulse approximation and an experimental transmission defined. These experimental transmissions are considerably larger (a factor of {similar to}2 for {sup 181}Ta) than those one would calculate from the free {ital N}-{ital N} cross sections folded into the nuclear density distribution. A new calculation that includes medium effects ({ital N}-{ital N} correlations, density dependence of the {ital N}-{ital N} cross sections and Pauli suppression) accounts for this increase.

  20. Relativistic extension of the complex scaled Green's function method for resonances in deformed nuclei

    NASA Astrophysics Data System (ADS)

    Shi, Min; Shi, Xin-Xing; Niu, Zhong-Ming; Sun, Ting-Ting; Guo, Jian-You

    2017-03-01

    We have extended the complex scaled Green's function method to the relativistic framework describing deformed nuclei with the theoretical formalism presented in detail. We have checked the applicability and validity of the present formalism for exploration of the resonances in deformed nuclei. Furthermore, we have studied the dependences of resonances on nuclear deformations and the shape of potential, which are helpful to recognize the evolution of resonant levels from stable nuclei to exotic nuclei with axially quadruple deformations.

  1. Collisions of deformed nuclei and superheavy-element production

    SciTech Connect

    Iwamoto, Akira; Moeller, P. |||; Nix, J.R.; Sagawa, Hiroyuki, Sagawa

    1995-09-01

    A detailed understanding of complete fusion cross sections in heavy-ion collisions requires a consideration of the effects of the deformation of the projectile and target. The aim here is to show that deformation and orientation of the colliding nuclei have a very significant effect on the fusion-barrier height and on the compactness of the touching configuration. To facilitate discussions of fusion configurations of deformed nuclei, the authors develop a classification scheme and introduce a notation convention for these configurations. They discuss particular deformations and orientations that lead to compact touching configurations and to fusion-barrier heights that correspond to fairly low excitation energies of the compound systems. Such configurations should be the most favorable for producing superheavy elements. They analyze a few projectile-target combinations whose deformations allow favorable entrance-channel configurations and whose proton and neutron numbers lead to compound systems in a part of the superheavy region where a half-lives are calculated to be observable, that is, longer than 1 {micro}s.

  2. Surface direct nuclear photoeffect in heavy deformed nuclei

    NASA Astrophysics Data System (ADS)

    Ishkhanov, B. S.; Orlin, V. N.; Stopani, K. A.

    2016-11-01

    A mechanism of photon-induced direct knockout of a nucleon from the nuclear surface without formation of intermediate excited nuclear state is described. The effect plays an important role at least for the (γ ,p ) reaction on heavy nuclei in the energy region centered at about 30 MeV where the probability of formation of the giant dipole resonance is already small but quasideuteron photoabsorption still does not prevail. A compact model of the surface direct nuclear photoeffect (SDNP) in heavy deformed nuclei that can be used to calculate the differential d σ (Eγ,ϑ )/d Ω and total σ (Eγ) cross sections of the SDNP under adiabatic approximation is formulated. The model is applied to calculation of the (γ ,p ) reaction cross sections on 160Gd and W,186184. The importance of the SDNP effect for these nuclei at Eγ˜30 MeV is demonstrated.

  3. The Onset of Deformation in Neutron-Deficient At Nuclei

    SciTech Connect

    Smith, M.B.; Chapman, R.; Cocks, J.F.C.; Dorvaux, O.; Helariutta, K.; Jones, P.M.; Julin, R.; Juutinen, S.; Kankaanpaa, H.; Kettunen, H.; Kuusiniemi, P.; Le Coz, Y.; Leino, M.; Middleton, D.J.; Muikku, M.; Nieminen, P.; Rahkila, P.; Savelius, A.; Spohr, K.-M.

    1999-12-31

    Excited states in the {sup 197}At nucleus have been identified for the first time using the recoil-decay-tagging technique. The excitation energy of these states is found to be consistent with the systematics of neutron-deficient At nuclei and with calculations indicating that the nucleus may be deformed in its ground state. A more recent experiment, to study states in {sup 195}At, is discussed.

  4. The onset of deformation in neutron-deficient At nuclei

    SciTech Connect

    Smith, M. B.; Chapman, R.; Middleton, D. J.; Spohr, K.-M.; Cocks, J. F. C.; Dorvaux, O.; Helariutta, K.; Jones, P. M.; Julin, R.; Juutinen, S.; Kankaanpaeae, H.; Kettunen, H.; Kuusiniemi, P.; Leino, M.; Muikku, M.; Nieminen, P.; Rahkila, P.; Savelius, A.; Coz, Y. Le

    1999-11-16

    Excited states in the {sup 197}At nucleus have been identified for the first time using the recoil-decay-tagging technique. The excitation energy of these states is found to be consistent with the systematics of neutron-deficient. At nuclei and with calculations indicating that the nucleus may be deformed in its ground state. A more recent experiment, to study states in {sup 195}At, is discussed.

  5. Orientation dependent behavior of the Coulomb barrier parameters for deformed-deformed nuclei

    NASA Astrophysics Data System (ADS)

    Ismail, M.; Adel, A.

    2011-06-01

    The Coulomb barrier parameters (radius, R, and height, V) for the interaction between two deformed nuclei are calculated in phenomenological way in the framework of the double folding model with the realistic M3Y nucleon-nucleon ( NN) interaction. The variations of R and V for the reactions Ar48+Pu238, Mg26+Cm248, Mg26+U238, and Ne22+U238 in the orientation degrees of freedom are investigated. It is found that the distribution of the Coulomb barrier parameters in the orientation degrees of freedom shows almost the same patterns as the sum of the nuclear radii of the interacting nuclei along the direction of the separation vector joining their two centers of mass. The orientation Coulomb barrier radius distribution follows the same variations as the sum of radii while the barrier height distribution follows it inversely. This correlation (anticorrelation) between R ( V) and the nuclear radii of the deformed nuclei dose not give the values of R and V. This suggests a simple and straightforward way to predict the behavior of the barrier parameters with different orders of deformations without performing the heavy numerical calculations necessary when the two nuclei are being deformed. It also allows us to estimate, with reasonable accuracy, the compact and elongated configurations of the interacting nuclei which lead to hot and cold fusion reactions, respectively.

  6. Microscopic and self-consistent description for neutron halo in deformed nuclei

    SciTech Connect

    Li Lulu; Meng Jie; Zhao Enguang; Zhou Shangui

    2013-05-06

    A deformed relativistic Hartree-Bogoliubov theory in continuum has been developed for the study of neutron halos in deformed nuclei and the halo phenomenon in deformed weakly bound nuclei is investigated. Magnesium and neon isotopes are studied and some results are presented for the deformed neutron-rich and weakly bound nuclei {sup 44}Mg and {sup 36}Ne. The core of the former nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the existence of halos in deformed nuclei and for the occurrence of this decoupling effect are discussed.

  7. Proxy-SU(3) symmetry in heavy deformed nuclei

    NASA Astrophysics Data System (ADS)

    Bonatsos, Dennis; Assimakis, I. E.; Minkov, N.; Martinou, Andriana; Cakirli, R. B.; Casten, R. F.; Blaum, K.

    2017-06-01

    Background: Microscopic calculations of heavy nuclei face considerable difficulties due to the sizes of the matrices that need to be solved. Various approximation schemes have been invoked, for example by truncating the spaces, imposing seniority limits, or appealing to various symmetry schemes such as pseudo-SU(3). This paper proposes a new symmetry scheme also based on SU(3). This proxy-SU(3) can be applied to well-deformed nuclei, is simple to use, and can yield analytic predictions. Purpose: To present the new scheme and its microscopic motivation, and to test it using a Nilsson model calculation with the original shell model orbits and with the new proxy set. Method: We invoke an approximate, analytic, treatment of the Nilsson model, that allows the above vetting and yet is also transparent in understanding the approximations involved in the new proxy-SU(3). Results: It is found that the new scheme yields a Nilsson diagram for well-deformed nuclei that is very close to the original Nilsson diagram. The specific levels of approximation in the new scheme are also shown, for each major shell. Conclusions: The new proxy-SU(3) scheme is a good approximation to the full set of orbits in a major shell. Being able to replace a complex shell model calculation with a symmetry-based description now opens up the possibility to predict many properties of nuclei analytically and often in a parameter-free way. The new scheme works best for heavier nuclei, precisely where full microscopic calculations are most challenged. Some cases in which the new scheme can be used, often analytically, to make specific predictions, are shown in a subsequent paper.

  8. Penetration factor in deformed potentials: Application to α decay with deformed nuclei

    NASA Astrophysics Data System (ADS)

    Ismail, M.; Ellithi, A. Y.; Botros, M. M.; Abdurrahman, A.

    2012-10-01

    A new averaging process of the calculation of α-decay half-lives for heavy and superheavy nuclei is studied in the framework of a deformed density-dependent cluster model. The potential between a spherical α particle and a deformed daughter nucleus is calculated numerically from the double-folding model by the multipole expansion method. The nuclear potential is calculated at each α-particle emission angle applying the Bohr-Sommerfeld condition at each case. The penetration factors and the half-lives for all the emission angles are evaluated with the new averaging process and compared with older values based on a fixed value of the nuclear potential depth. Finally, the half-lives of 83 even-even heavy nuclei in the atomic-number range 82-118 are calculated by the two methods and compared with their experimental values and the corresponding half-lives of the spherical daughter nuclei.

  9. Deformed Brueckner-Hartree-Fock calculation for light nuclei

    NASA Technical Reports Server (NTRS)

    Braley, R. C.; Ford, W. F.; Becker, R. L.; Patterson, M. R.

    1971-01-01

    For the first time the Brueckner-Hartree-Fock (BHF) method was applied to nuclei whose intrinsic structure is nonspherical. One aim was to investigate whether the energy dependent reaction matrix calculated from a realistic nucleon-nucleon interaction leads to deformations similar to, or different from, those obtained from energy independent interactions in Hartree-Fock (HF) calculations. Reaction matrix elements were calculated as a function of starting energy for the Hamada-Johnston interaction, using a Pauli operator appropriate to O-16 and a shifted oscillator spectrum for virtual excited states. Binding energies, single-particle energies, radii, and shape deformations of the intrinsic state in unrenormalized as well as renormalized BHF are discussed and compared with previous HF studies. Results are presented for C-12, O-16, and Ne-20.

  10. The energy dependence of nucleon propagation in nuclei as measured in the (e,e{prime}p) reaction

    SciTech Connect

    Geesaman, D.F.; Fedchak, J.A.; Hansen, J.O.

    1995-08-01

    A proposal was approved by the CEBAF PAC-5 to continue (e,e`p) studies of proton propagation in nuclei for protons in the energy range of 400-2000 MeV. In this energy range the nature of the N-N interaction changes from elastic to highly inelastic once the pion-production threshold is crossed. The theoretical description of proton propagation also changes considerably from nonrelativistic optical potentials to relativistic potentials to Glauber models. Information on proton propagation in this energy range is quite important to the CEBAF coincidence program. At higher energies, this reaction is used to study manifestations of more exotic mechanisms, such as increased transparency for hard collisions - color transparency. The experiment will be carried out in the CEBAF Hall C using the HMS 6-GeV spectrometer and the SOS 1.8-GeV spectrometer. Electrons in the quasifree region will be detected in coincidence with protons with missing energies of less than 100 MeV. At two proton energies, Tp = 400 MeV and Tp = 1000 MeV, Rosenbluth separations will be performed to study the A dependence of the longitudinal and transverse coincidence response independently. Since this proposal concentrates on the quasifree region, the projected count rates are relatively high and the background rates are calculated to be quite low. The collaboration developing the equipment for Hall C has chosen this experiment to be the tune-up experiment and the first experiment to be performed at CEBAF. It is expected to receive beam in Spring 1995.

  11. Tunneling from super- to normal-deformed minima in nuclei.

    SciTech Connect

    Khoo, T. L.

    1998-01-08

    An excited minimum, or false vacuum, gives rise to a highly elongated superdeformed (SD) nucleus. A brief review of superdeformation is given, with emphasis on the tunneling from the false to the true vacuum, which occurs in the feeding and decay of SD bands. During the feeding process the tunneling is between hot states, while in the decay it is from a cold to a hot state. The {gamma} spectra connecting SD and normal-deformed (ND) states provide information on several physics issues: the decay mechanism; the spin/parity quantum numbers, energies and microscopic structures of SD bands; the origin of identical SD bands; the quenching of pairing with excitation energy; and the chaoticity of excited ND states at 2.5-5 MeV. Other examples of tunneling in nuclei, which are briefly described, include the possible role of tunneling in {Delta}I = 4 bifurcation in SD bands, sub-barrier fusion and proton emitters.

  12. Possible octupole deformation in Cs and Ba nuclei from their differential radii

    SciTech Connect

    Sheline, R.K.; Jain, A.K.; Jain, K.

    1988-12-01

    The odd-even staggering of the differential radii of Fr and Ra and the Cs and Ba nuclei is compared. This staggering is inverted in the region of known octupole deformation in the Fr and Ra nuclei. The normal staggering is eliminated in the Cs nuclei and attenuated in the Ba nuclei for neutron numbers 85--88. This fact is used to suggest the possible existence of octupole deformation and its neutron number range in the Cs and Ba nuclear ground states.

  13. Excitation of discrete levels of {sup 63}Cu and {sup 65}Cu nuclei in (e, e') reactions

    SciTech Connect

    Denyak, V. V. Khvastunov, V. M.; Paschuk, S. A.; Schelin, H. R.; Khomich, A. A.; Shevchenko, N. G.

    2010-03-15

    Inelastic electron scattering on {sup 63}Cu and {sup 65}Cu nuclei at excitation energies of up to 5 MeV was studied. Information about the reduced probability and multipolarity of transitions was obtained for 11 low-lying levels and groups of levels of the {sup 63}Cu nucleus and for 17 such levels and groups of levels of the {sup 65}Cu nucleus. It was shown that the experimental form factors for inelastic scattering accompanied by the excitation of discrete levels and group of levels of these nuclei with a nonzero spin can be described in terms of a single multipolarity, even though the law of angular-momentum conservation admits the existence of several more multipolarities yielding the same parity of an excited state.

  14. Coupled-Channels Study of α-DECAY Rates for Deformed Nuclei

    NASA Astrophysics Data System (ADS)

    Ni, Dongdong; Ren, Zhongzhou

    The generalized density-dependent cluster model is devoted to calculate α-decay half-lives of spherical and deformed nuclei. The multi-channel cluster model is developed to describe the α-decay fine structure in heavy deformed nuclei, including half-lives and branching ratios. After a brief review of these two models, special cases of the α-decay fine structure are presented. Calculations are separately performed using the coupled-channels and WKB approaches.

  15. {Delta}I = 2 energy staggering in normal deformed dysprosium nuclei

    SciTech Connect

    Riley, M.A.; Brown, T.B.; Archer, D.E.

    1996-12-31

    Very high spin states (I{ge}50{Dirac_h}) have been observed in {sup 155,156,157}Dy. The long regular band sequences, free from sharp backbending effects, observed in these dysprosium nuclei offer the possibility of investigating the occurence of any {Delta}I = 2 staggering in normal deformed nuclei. Employing the same analysis techniques as used in superdeformed nuclei, certain bands do indeed demonstrate an apparent staggering and this is discussed.

  16. Proximity potential for heavy ion reactions on deformed nuclei

    SciTech Connect

    Baltz, A. J.; Bayman, B. F.

    1982-01-01

    The usual treatment of the deformed optical model for analysis of heavy ion induced inelastic scattering data involves a deformed (target) radius, a spherical (projectile) radius and a potential strength dependent on the surface separation along the line between the two centers. Several authors using various approaches have shown that this center line potential is geometrically inadequate especially for description of higher L deformation parameters probed in heavy ion induced inelastic scattering experiments. A quantitatively adequate form of the deformed proximity potential suitable for use with a coupled channels reaction code in the analysis of inelastic scattering data above the Coulomb barrier is described. A major objective is to be able to extract reliably higher deformed multipole moments from such data. The deformed potential calculated in the folding model will serve as a geometrically exact benchmark to evaluate the accuracy of the proximity potential prescriptions. (WHK)

  17. Evolution of surface deformations of weakly bound nuclei in the continuum

    NASA Astrophysics Data System (ADS)

    Pei, J. C.; Zhang, Y. N.; Xu, F. R.

    2013-05-01

    We study weakly bound deformed nuclei based on the coordinate-space Skyrme Hartree-Fock-Bogoliubov (HFB) approach, in which a large box is employed for treating the continuum and large spatial extensions. When the limit of the core-halo deformation decoupling is approached, calculations found an exotic “egg”-like structure consisting of a spherical core plus a prolate halo in 38Ne, in which the near-threshold nonresonant continuum plays an essential role. Generally the halo probability and the decoupling effect in heavy nuclei can be hindered by high level densities around Fermi surfaces. However, deformed halos in medium-mass nuclei are possible as the negative-parity levels are sparse, e.g., in 110Ge. The deformation decoupling has also been demonstrated in pairing density distributions.

  18. Study of the (e,e'p) quasi-elastic reaction in complex nuclei: theory and experiment

    SciTech Connect

    Herraiz, Joaquin Lopez

    2010-03-01

    Experimental coincidence cross section and transverse-longitudinal asymmetry ATL have been obtained for the quasielastic (e,e'p) reaction in 16O, 12C, and {sup 208}Pb in constant q-ω kinematics in the missing momentum range -350 < pmiss < 350 MeV/c. In these experiments, performed in experimental Hall A of the Thomas Jefferson National Accelerator Facility (JLAB), the beam energy and the momentum and angle of the scattered electrons were kept fixed, while the angle between the proton momentum and the momentum transfer q was varied in order to map out the missing momentum distribution. The experimental cross section and ATL asymmetry have been compared with Monte Carlo simulations based on Distorted Wave Impulse Approximation (DWIA) calculations with both relativistic and non-relativistic spinor structure. The spectroscopic factors obtained for both models are in agreement with previous experimental values, while ATL measurements favor the relativistic DWIA calculation. This thesis describes the details of the experimental setup, the calibration of the spectrometers, the techniques used in the data analysis to derive the final cross sections and the ATL, the ingredients of the theoretical calculations employed and the comparison of the results with the simulations based on these theoretical models.

  19. Constrained Hartree-Fock Theory and Study of Deformed Structures of Closed Shell Nuclei

    NASA Astrophysics Data System (ADS)

    Praharaj, Choudhury

    2016-03-01

    We have studied some N or Z = 50 nuclei in a microscopic model with effective interaction in a reasonably large shell model space. Excitation of particles across 50 shell closure leads to well-deformed excited prolate configurations. The potential energy surfaces of nuclei are studied using Hartree-Fock theory with quadrupole constraint to explore the various deformed configurations of N = 50 nuclei 82Ge , 84Se and 86Kr . Energy spectra are calculated from various intrinsic states using Peierls-Yoccoz angular momentum projection technique. Results of spectra and electromagnetic moments and transitions will be presented for N = 50 nuclei and for Z = 50 114Sn nucleus. Supported by Grant No SB/S2/HEP-06/2013 of DST.

  20. Why are the interband transitions among triaxially strongly deformed bands suppressed in even nuclei?

    SciTech Connect

    Sugawara-Tanabe, Kazuko; Tanabe, Kosai

    2011-05-06

    As top-on-top model has made a great success in explaining triaxially strongly deformed (TSD) bands in odd-A nuclei, we extend this model to even-A nuclei, i.e. two particles in different single-particle orbitals outside the triaxial rotor. In the lowest order approximation, the electromagnetic transitions between TSD bands in even-A case are reduced by a factor of 0.04 compared with odd-A case. It is one of the reasons why TSD bands are not yet explicitly observed in even-A nuclei.

  1. Cluster radioactivity with effects of deformations and orientations of nuclei included

    SciTech Connect

    Arun, Sham K.; Gupta, Raj K.; Kanwar, Shefali; Singh, BirBikram; Sharma, Manoj K.

    2009-09-15

    Based on the preformed cluster model (PCM) of Gupta and collaborators, we have extended our recent study on ground-state cluster decays to parent nuclei resulting in daughters other than spherical {sup 208}Pb, i.e., to deformed daughters, and the very new cases of {sup 14}C and {sup 15}N decays of {sup 223}Ac, and {sup 34}Si decay of {sup 238}U, taking nuclei as spherical, quadrupole deformed ({beta}{sub 2}) alone, and with higher multipole deformations up to hexadecapole ({beta}{sub 2}, {beta}{sub 3}, {beta}{sub 4}) together with the 'optimum' orientations of cold decay process. Except for {sup 14}C decays of {sup 221}Fr, {sup 221-224,226}Ra, and {sup 225}Ac where higher multipole deformations up to {beta}{sub 4} are found essential, the quadrupole deformation {beta}{sub 2} alone is found good enough to fit the experimental data. Because the PCM treats the cluster-decay process as the tunneling of a preformed cluster, the deformations and orientations of nuclei modify both the preformation probability P{sub 0} and tunneling probability P, and hence the decay half-life, considerably.

  2. Coulomb form factors of odd-A nuclei within an axially deformed relativistic mean-field model

    NASA Astrophysics Data System (ADS)

    Liu, Jian; Xu, Chang; Wang, Shuo; Ren, Zhongzhou

    2017-09-01

    Background: The nuclear Coulomb form factor | FC(q) | 2 is a useful tool to study nuclear structure. For spherical nuclei, | FC(q) | 2 can be calculated by combining the spherical relativistic mean-field (RMF) model and the distorted wave Born approximation (DWBA) method. Purpose: In a previous paper, the axially deformed RMF model + DWBA method was successfully applied to study the Coulomb form factors of deformed even-even nuclei. In this paper, we further extend this method to study the Coulomb form factors of deformed odd-A nuclei. Method: First, the charge distributions of odd-A nuclei are calculated with the deformed RMF model and expanded into multipole components. Next, with the multipole moment charge distributions, the Coulomb multipoles C 0 , C 2 , and C 4 are calculated. Finally, by summing over Coulomb multipoles required, the Coulomb form factors of odd-A nuclei can be obtained. Results: For deformed odd-A nuclei, the theoretical Coulomb form factors calculated from the deformed RMF charge densities are in better agreement with the experimental data. For nuclei with J ≥1 , the diffraction minima of Coulomb form factors are much flatter, which is due to the contributions of quadrupole charge distributions. Conclusions: Results indicate that the axially deformed RMF model can give reasonable descriptions for multipole moment charge distributions of odd-A nuclei. The method in this paper can provide a useful guide for future experiments of electron scattering off exotic odd-A nuclei.

  3. Projected shell model for Gamow-Teller transitions in heavy, deformed nuclei

    NASA Astrophysics Data System (ADS)

    Wang, Long-Jun; Sun, Yang; Gao, Zao-Chun; Kiran Ghorui, Surja

    2016-02-01

    Calculations of Gamow-Teller (GT) transition rates for heavy, deformed nuclei, which are useful input for nuclear astrophysics studies, are usually done with the quasiparticle random-phase approximation. We propose a shell-model method by applying the Projected Shell Model (PSM) based on deformed bases. With this method, it is possible to perform a state-by-state calculation for nuclear matrix elements for β-decay and electron-capture in heavy nuclei. Taking β- decay from 168Dy to 168Ho as an example, we show that the known experimental B(GT) from the ground state of the mother nucleus to the low-lying states of the daughter nucleus could be well described. Moreover, strong transitions to high-lying states are predicted to occur, which may considerably enhance the total decay rates once these nuclei are exposed to hot stellar environments.

  4. Exotic modes of excitation in deformed neutron-rich nuclei

    SciTech Connect

    Yoshida, Kenichi

    2011-05-06

    Low-lying dipole excitation mode in neutron-rich Mg isotopes close to the drip line is investigated in the framework of the Hartree-Fock-Bogoliubov and the quasiparticle random-phase approximation employing the Skyrme and the pairing energy-density functionals. It is found that the low-lying dipole-strength distribution splits into the K{sup {pi}} = 0{sup -} and 1{sup -} components due to the nuclear deformation. The low-lying dipole strength increases as the neutron drip-line is approached.

  5. Microscopic description of collective states near the yrast line of nuclei with stable octupole deformation

    NASA Astrophysics Data System (ADS)

    Kvasil, J.; Nazmitdinov, R. G.

    1985-06-01

    Collective states near the yrast line in nuclei with stable octupole deformation are discussed in the framework of the random phase approximation (RPA) based on the cranking model. These vibrational states are characterized by the quantum number of generalized signature (eigenvalue of the operator Sx = PRx-1( π)). In the zero-octupole deformation limit the RPA equations of motion are reduced to the well-known ones characterized by both values of parity and signature, respectively. The connection of the translational and rotational symmetry of the model hamiltonian with the spurious solutions of the RPA equation of motion is discussed. Expressions for the reduced probabilities B(E1), B(E2) and B(E3) are obtained. These expressions confirm the conclusions of phenomenological models for the strong E1 and E3 intraband transitions in nuclei with stable octupole deformation.

  6. Disappearance of Z=120 & 126 magicity and presence of hyper deformations in superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Sharma, M. M.; Farhan, A. R.

    2012-10-01

    Conventional wisdom has it that Z=120 and especially Z=126 are predicted to be magic numbers for extreme superheavy nuclei. We have undertaken a study of structure of superheavy nuclei in the region of Z=120 to Z=126 within the framework of the deformed relativistic Hartree-Bogoliubov (DRHB) approach. Nuclei in this region entail a large density of states and are thus susceptible to a coupling to the continuum especially those which are close to being proton unbound. The DRHB approach which takes into account the coupling to the continuum is suitable for nuclei in the end of the periodic table. Additionally, the pairing in this approach is included within the Bogoliubov quasi-particle scheme, which takes into account the shell gap at the Fermi surface appropriately. Using the successful Lagrangian model NL-SV1 [1] based upon the vector self-coupling of φ-meson, it is shown that the perceived shell gaps at Z=120 and Z=126 disappear, thus making these proton numbers as non-magic. It is also shown that due to very large Coulomb force acting in these nuclei which are virtually at the end of the periodic table, stability to the nuclei in this region is brought about by extremely large elongated shapes with β2 ˜ 0.70-0.80. Consequences on formation of superheavy nuclei in this region will be discussed.

  7. Excited states of deformable odd {sup 157,159}Tb nuclei: Nonconservation of the angular momentum of external nucleon

    SciTech Connect

    Sharipov, Sh.; Ermamatov, M. J.

    2009-01-15

    The previously developed rotationally single-particle and vibrational model of the triaxial deformable odd nuclei is extended to the case where the total angular momentum of an external nucleon is not conserved. The calculated ratios of the excitation energies of the {sup 157,159}Tb nuclei are compared with the existing experimental data. The ratios of E2-transition probabilities and those of quadrupole moments of the above nuclei are calculated using parameters determined from the spectra of these nuclei.

  8. Heavy-Ion Transfer Reactions with Deformed Nuclei

    NASA Astrophysics Data System (ADS)

    Helmer, Karl Gerard

    1992-01-01

    One-neutron transfer reactions involving actinide nuclei are used to investigate the effects of rotational motion on transfer populations. Deexcitation gamma rays were measured using a particle -particle-gamma triple coincidence method. Rotational states up to 28^{+ }(30^{+}) were seen in ^{234}U originating from the reaction ^{235}U( ^{206}Pb, ^ {207}Pb)^{234} U at a laboratory bombarding energy of 1394 MeV. Angular distributions for both inelastic excitation and transfer are presented and the one-neutron transfer reaction cross section as well as the grazing angle have been extracted. This study demonstrates the feasibility of using heavy-ion induced transfer reactions for spectroscopic studies. The second section of this thesis explores the question of diabolical pair transfer in nuclear physics using the reactions ^{206}Pb( ^{156}Gd, ^ {154}Gd)^{208} Pb (diabolical case) and ^{206 }Pb(^{156}Gd, ^{158}Gd)^ {204}Pb (nondiabolic case) at a laboratory bombarding energy of 888 MeV. Early calculations by Nikam, Ring and Canto predicted oscillatory behavior of pair transfer matrix elements as the cranking frequency was varied, within the cranking Hartree-Fock-Bogoliubov (CHFB) model, and explained this behavior as a manifestation of Berry's phase. Significant suppression of the high spin population in the diabolical nucleus was predicted. The diabolical point is supplied by the crossing of the ground-state band with the two-quasiparticle band. The strength of this band interaction is predicted to be oscillatory with chemical potential in the CHFB model. The study of pair transfer populations can therefore shed light not only on the possible existence of Berry's phase in nuclear systems, but also on whether the band interaction goes strictly to zero as predicted by the CHFB model. The results of this experiment agree with the latest calculations that the expected effects are more subtle than the earliest calculations predicted.

  9. Nonmonotonic Self-Deformation of Cell Nuclei on Topological Surfaces with Micropillar Array.

    PubMed

    Liu, Xiangnan; Liu, Ruili; Gu, Yexin; Ding, Jiandong

    2017-06-07

    Cells respond to the mechanical signals from their surroundings and integrate physiochemical signals to initiate intricate mechanochemical processes. While many studies indicate that topological features of biomaterials impact cellular behaviors profoundly, little research has focused on the nuclear response to a mechanical force generated by a topological surface. Here, we fabricated a polymeric micropillar array with an appropriate dimension to induce a severe self-deformation of cell nuclei and investigated how the nuclear shape changed over time. Intriguingly, the nuclei of mesenchymal stem cells (MSCs) on the poly(lactide-co-glycolide) (PLGA) micropillars exhibited a significant initial deformation followed by a partial recovery, which led to an "overshoot" phenomenon. The treatment of cytochalasin D suppressed the recovery of nuclei, which indicated the involvement of actin cytoskeleton in regulating the recovery at the second stage of nuclear deformation. Additionally, we found that MSCs exhibited different overshoot extents from their differentiated lineage, osteoblasts. These findings enrich the understanding of the role of the cell nucleus in mechanotransduction. As the first quantitative report on nonmonotonic kinetic process of self-deformation of a cell organelle on biomaterials with unique topological surfaces, this study sheds new insight into cell-biomaterial interactions.

  10. Influence of hexadecapole deformation on production cross sections of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Bao, X. J.; Guo, S. Q.; Zhang, H. F.; Li, J. Q.

    2016-12-01

    The current heaviest superheavy nuclei (SHN) are experimentally synthesized by using 48Ca to bombard actinide nuclei via fusion reactions. Actinide nuclei often have considerable hexadecapole deformation in addition to quadrupole deformation, which was not considered in previous theoretical studies. With the dinuclear system concept, and by taking the hexadecapole deformation in to consideration in addition to the quadrupole deformation, the hot fusion probability leading to the synthesis of SHN is investigated systematically. Synthesis of superheavy elements 296118 and 295118 by using the 48Ca+251Cf reaction channel is evaluated and discussed, and the maximal evaporation residue cross sections (ERCSs) of the 3n and 4n channels are predicted to be 1.90 and 0.11 pb, respectively. The predicted maximum ERCSs in 3n and 4n evaporation channels of the 249Bk(50Ti,xn){}299-x119 reaction are 0.12 and 0.04 pb, respectively. The most favorable reaction to synthesize the element Z = 120 turns out to be 251Cf(50Ti,xn){}301-x120, but the predicted maximum cross section for this reaction is only 67 fb. Therefore, superheavy element 119 may be the most hopeful new element for Z\\gt 118 to be synthesized under some improved experimental conditions in the near future.

  11. Orientation effects of deformed nuclei on the production of superheavy elements

    SciTech Connect

    Wang Nan; Li Junqing; Zhao Enguang

    2008-11-15

    Within the dinuclear system model, the effects of the relative orientations of interacting deformed nuclei on the interaction potential energy surfaces, the evaporation residue cross sections of some cold fusion reactions leading to superheavy elements are investigated. The competition between fusion and quasifission is studied to show the effect of the orientation. It turns out that the belly-belly orientation is in favor of the production of superheavy nuclei, because in the case a barrier has suppressed the quasifission and thus helped fusion.

  12. Orientation effects of deformed nuclei on the production of superheavy elements

    NASA Astrophysics Data System (ADS)

    Wang, Nan; Li, Jun-Qing; Zhao, En-Guang

    2008-11-01

    Within the dinuclear system model, the effects of the relative orientations of interacting deformed nuclei on the interaction potential energy surfaces, the evaporation residue cross sections of some cold fusion reactions leading to superheavy elements are investigated. The competition between fusion and quasifission is studied to show the effect of the orientation. It turns out that the belly-belly orientation is in favor of the production of superheavy nuclei, because in the case a barrier has suppressed the quasifission and thus helped fusion.

  13. Directional Correlation of Nuclear-Collision Probability for Aligned Beams of Deformed Nuclei

    NASA Astrophysics Data System (ADS)

    Fukuda, Mitsunori; Tanaka, Masaomi; Yamaoka, Shintaro; Ohno, Junichi; Mihara, Mototsugu; Matsuta, Kensaku; Nishimura, Daiki; Yoshinaga, Kenta; Takechi, Maya; Ohtsubo, Takashi; Izumikawa, Takuji; Nagashima, Masayuki; Suzuki, Takeshi; Yamaguchi, Takayuki; Kitagawa, Atsushi; Sato, Shinji; Suzuki, Shinji; Fukuda, Shigekazu; Himac H093 Collaboration

    2014-09-01

    In the long history of nuclear physics, a lot of observables have been discussed in connection with the nuclear deformation. In this work, an investigation have been carried out on the directional correlation of the nuclear-collision probability between the direction of beam of deformed nuclei and the deformation axis, to sense the nuclear deformation directly. Few experimental studies of this kind have been done because of the difficulties in producing aligned beams. We utilized the projectile fragmentation to produce the aligned nuclear beams. We tested these measurements for 9Be, 10B, and 26Al at the HIMAC facility. By selecting the parallel momentum using the separator, spin aligned beams were produced, with which the interaction cross sections were measured. The cross sections were precisely measured as a function of longitudinal momentum. We will report on the details of measurements and discussions on this intriguing result.

  14. Effective field theory of emergent symmetry breaking in deformed atomic nuclei

    DOE PAGES

    Papenbrock, Thomas F.; Weidenmüller, H. A.

    2015-09-03

    Spontaneous symmetry breaking in non-relativistic quantum systems has previously been addressed in the framework of effective field theory. Low-lying excitations are constructed from Nambu–Goldstone modes using symmetry arguments only. In this study, we extend that approach to finite systems. The approach is very general. To be specific, however, we consider atomic nuclei with intrinsically deformed ground states. The emergent symmetry breaking in such systems requires the introduction of additional degrees of freedom on top of the Nambu–Goldstone modes. Symmetry arguments suffice to construct the low-lying states of the system. Lastly, in deformed nuclei these are vibrational modes each of whichmore » serves as band head of a rotational band.« less

  15. Linear response of light deformed nuclei investigated by self-consistent quasiparticle random-phase approximation

    SciTech Connect

    Losa, C.; Doessing, T.; Pastore, A.; Vigezzi, E.; Broglia, R. A.

    2010-06-15

    We present a calculation of the properties of vibrational states in deformed, axially-symmetric even-even nuclei, within the framework of a fully self-consistent quasiparticle random phase approximation (QRPA). The same Skyrme energy density and density-dependent pairing functionals are used to calculate the mean field and the residual interaction in the particle-hole and particle-particle channels. We have tested our software in the case of spherical nuclei against fully self-consistent calculations published in the literature, finding excellent agreement. We investigate the consequences of neglecting the spin-orbit and Coulomb residual interactions in QRPA. Furthermore we discuss the improvement obtained in the QRPA result associated with the removal of spurious modes. Isoscalar and isovector responses in the deformed {sup 24-26}Mg, {sup 34}Mg isotopes are presented and compared to experimental findings.

  16. Gamow-Teller {beta}{sup +} decay of deformed nuclei near the proton drip line

    SciTech Connect

    Frisk, F.; Hamamoto, I.; Zhang, X.Z. |

    1995-11-01

    Using a quasiparticle Tamm-Dancoff approximation (TDA) based on deformed Hartree-Fock (HF) calculations with Skyrme interactions, the distribution of the Gamow-Teller (GT) {beta}{sup +} decay strength is estimated for the HF local minima of even-even deformed nuclei near the proton drip line in the region of 28{lt}{ital Z}{lt}66. The distribution often depends sensitively on the nuclear shape (namely, oblate or prolate). In the region of {ital Z}{lt}50 the possibility of observing {beta}-delayed proton emission depends sensitively on the excess of {ital Z} over {ital Z}={ital N}. In the region of {ital Z}{gt}50 almost the entire estimated GT strength is found to lie below the ground states of the even-even mother nuclei, and the observation of the total GT strength by {beta}-delayed charged-particle(s) emission will be of essential importance.

  17. Effective field theory of emergent symmetry breaking in deformed atomic nuclei

    SciTech Connect

    Papenbrock, Thomas F.; Weidenmüller, H. A.

    2015-09-03

    Spontaneous symmetry breaking in non-relativistic quantum systems has previously been addressed in the framework of effective field theory. Low-lying excitations are constructed from Nambu–Goldstone modes using symmetry arguments only. In this study, we extend that approach to finite systems. The approach is very general. To be specific, however, we consider atomic nuclei with intrinsically deformed ground states. The emergent symmetry breaking in such systems requires the introduction of additional degrees of freedom on top of the Nambu–Goldstone modes. Symmetry arguments suffice to construct the low-lying states of the system. Lastly, in deformed nuclei these are vibrational modes each of which serves as band head of a rotational band.

  18. Exact estimate of the α -decay rate and semiclassical approach in deformed nuclei

    NASA Astrophysics Data System (ADS)

    Delion, D. S.; Liotta, R. J.; Wyss, R.

    2015-11-01

    We compare the quantum mechanical procedures to estimate the total α -decay width from deformed nuclei in the laboratory and intrinsic systems of coordinates. Our analysis shows that the total half-life estimated in the intrinsic frame by neglecting the rotational motion of the core (adiabatic approach) is one order of magnitude smaller at β2=0.3 than the corresponding value in the spherical case. A similar calculation in the laboratory system of coordinates by considering the core motion (giving the correct theoretical estimate) predicts a reduction by only a factor of 2. The widely used "angular WKB" (Wentzel-Kramers-Brillouin) semiclassical procedure provides decay widths which are comparable to the adiabatic approach. We propose a new and very simple semiclassical "angular momentum WKB" procedure to evaluate the decay width in deformed nuclei. It provides decay widths very close to the ones obtained by the exact laboratory coupling channels procedure.

  19. New Method for Calculating the Potential Energy of Deformed Nuclei within the Liquid-Drop Model

    SciTech Connect

    Kurmanov, R.S.; Kosenko, G.I.

    2004-11-01

    The method that we previously developed for going over from double volume integrals to double surface integrals in calculating the Coulomb energy of nuclei that have a sharp surface is generalized to the case of nuclei where the range of nuclear forces is finite and where the nuclear surface is diffuse. New formulas for calculating the Coulomb and the nuclear energy of deformed nuclei are obtained within this approach. For a spherically symmetric nucleus, in which case there is an analytic solution to the problem in question, the results are compared with those that are quoted in the literature, and it is shown that the respective results coincide identically. A differential formulation of the method developed previously by Krappe, Nix, and Sierk for going over from double volume integrals to double surface integrals is proposed here on the basis of the present approach.

  20. QRPA Calculations for Spherical and Deformed Nuclei With the Gogny Force

    SciTech Connect

    Peru, S.

    2009-08-26

    Fully consistent axially-symmetric-deformed Quasi-particle Random Phase Approximation (QRPA) calculations have been performed with the D1S Gogny force. Dipole responses have been calculated in Ne isotopes to study the existence of soft dipole modes in exotic nuclei. A comparison between QRPA and generator coordinate method with Gaussian overlap approximation results is done for low lying 2{sup +} states in N = 16 isotones and Ni isotopes.

  1. Power-law rheology of isolated nuclei with deformation mapping of nuclear substructures.

    PubMed

    Dahl, Kris Noel; Engler, Adam J; Pajerowski, J David; Discher, Dennis E

    2005-10-01

    Force-induced changes in genome expression as well as remodeling of nuclear architecture in development and disease motivate a deeper understanding of nuclear mechanics. Chromatin and green fluorescent protein-lamin B dynamics were visualized in a micropipette aspiration of isolated nuclei, and both were shown to contribute to viscoelastic properties of the somatic cell nucleus. Reversible swelling by almost 200% in volume, with changes in salt, demonstrates the resilience and large dilational capacity of the nuclear envelope, nucleoli, and chromatin. Swelling also proves an effective way to separate the mechanical contributions of nuclear elements. In unswollen nuclei, chromatin is a primary force-bearing element, whereas swollen nuclei are an order of magnitude softer, with the lamina sustaining much of the load. In both cases, nuclear deformability increases with time, scaling as a power law-thus lacking any characteristic timescale-when nuclei are either aspirated or indented by atomic force microscopy. The nucleus is stiff and resists distortion at short times, but it softens and deforms more readily at longer times. Such results indicate an essentially infinite spectrum of timescales for structural reorganization, with implications for regulating genome expression kinetics.

  2. Power-Law Rheology of Isolated Nuclei with Deformation Mapping of Nuclear Substructures

    PubMed Central

    Dahl, Kris Noel; Engler, Adam J.; Pajerowski, J. David; Discher, Dennis E.

    2005-01-01

    Force-induced changes in genome expression as well as remodeling of nuclear architecture in development and disease motivate a deeper understanding of nuclear mechanics. Chromatin and green fluorescent protein-lamin B dynamics were visualized in a micropipette aspiration of isolated nuclei, and both were shown to contribute to viscoelastic properties of the somatic cell nucleus. Reversible swelling by almost 200% in volume, with changes in salt, demonstrates the resilience and large dilational capacity of the nuclear envelope, nucleoli, and chromatin. Swelling also proves an effective way to separate the mechanical contributions of nuclear elements. In unswollen nuclei, chromatin is a primary force-bearing element, whereas swollen nuclei are an order of magnitude softer, with the lamina sustaining much of the load. In both cases, nuclear deformability increases with time, scaling as a power law—thus lacking any characteristic timescale—when nuclei are either aspirated or indented by atomic force microscopy. The nucleus is stiff and resists distortion at short times, but it softens and deforms more readily at longer times. Such results indicate an essentially infinite spectrum of timescales for structural reorganization, with implications for regulating genome expression kinetics. PMID:16055543

  3. Deformed shell model results for neutrinoless double beta decay of nuclei in A = 60 - 90 region

    NASA Astrophysics Data System (ADS)

    Sahu, R.; Kota, V. K. B.

    2015-03-01

    Nuclear transition matrix elements (NTME) for the neutrinoless double beta decay (Oνββ or OνDBD) of 70Zn, 80Se and 82Se nuclei are calculated within the framework of the deformed shell model (DSM) based on Hartree-Fock (HF) states. For 70Zn, jj44b interaction in 2p3/2, 1f5/2, 2p1/2 and 1g9/2 space with 56Ni as the core is employed. However, for 80Se and 82Se nuclei, a modified Kuo interaction with the above core and model space are employed. Most of our calculations in this region were performed with this effective interaction. However, jj44b interaction has been found to be better for 70Zn. The above model space was used in many recent shell model (SM) and interacting boson model (IBM) calculations for nuclei in this region. After ensuring that DSM gives good description of the spectroscopic properties of low-lying levels in these three nuclei considered, the NTME are calculated. The deduced half-lives with these NTME, assuming neutrino mass is 1 eV, are 1.1 × 1026, 2.3 × 1027 and 2.2 × 1024 yr for 70Zn, 80Se and 82Se, respectively.

  4. Investigation of processes involved in quasi-elastic and Delta excitation region with (e,e'p) reaction on carbon- 12 nuclei

    NASA Astrophysics Data System (ADS)

    Yadav, Mahesh Kumar

    We have studied the 12C(e,e'X) reaction with an incident electron energy of 705 MeV and electron scattering angle of 34.4o. A large solid angle detector, the LAMPF BGO ball, was used to detect protons, pions, deuterons, photons, and neutrons in coincidence with the electron. The electron energy loss was varied from 40 to 450 MeV, thus covering kinematical regions from quasi-elastic scattering to the Δ(1232) resonance. The main focus of the thesis is a study of the Δ region with one or two protons in coincidence with the electron. A simulation program, ENIGMA, was used to model various reactions leading to emission of one or more protons plus neutrons or pions. We found that only two channels were required to reproduce the energy spectra and angular distributions of the (e,e' p) final state: (e,e' p/pi) and (e,e' pnn). The two nucleon final state (e,e' pn) was less than 10% of the cross section. The peak of the Δ(1232) resonance for various coincidences was found to be close to the position of the inclusive spectrum, except for the (e,e' pp) reaction where it increases to the highest measured values in energy loss, in contrast to proton induced reactions. The cross section for (e,e' pp) was found to be small and does not appear to result from direct two nucleon decay of the Δ(1232) resonance. In the quasi-elastic region we found that the kinetic energy spectrum of the proton could be reproduced by a combination of 80% (e,e' p) and 20% (e,e' pn). We were not able to determine whether or not the pn final state was due to final state interactions or two nucleon absorption.

  5. Skyrme random-phase-approximation description of lowest Kπ=2γ+ states in axially deformed nuclei

    NASA Astrophysics Data System (ADS)

    Nesterenko, V. O.; Kartavenko, V. G.; Kleinig, W.; Kvasil, J.; Repko, A.; Jolos, R. V.; Reinhard, P.-G.

    2016-03-01

    The lowest quadrupole γ -vibrational Kπ=2+ states in axially deformed rare-earth (Nd, Sm, Gd, Dy, Er, Yb, Hf, W) and actinide (U) nuclei are systematically investigated within the separable random-phase-approximation (SRPA) based on the Skyrme functional. The energies Eγ and reduced transition probabilities B (E 2 ) of 2γ+ states are calculated with the Skyrme forces SV-bas and SkM*. The energies of two-quasiparticle configurations forming the SRPA basis are corrected by using the pairing blocking effect. This results in a systematic downshift of Eγ by 0.3-0.5 MeV and thus in a better agreement with the experiment, especially in Sm, Gd, Dy, Hf, and W regions. For other isotopic chains, a noticeable overestimation of Eγ and too weak collectivity of 2γ+ states still persist. It is shown that domains of nuclei with low and high 2γ+ collectivity are related to the structure of the lowest two-quasiparticle states and conservation of the Nilsson selection rules. The description of 2γ+ states with SV-bas and SkM* is similar in light rare-earth nuclei but deviates in heavier nuclei. However SV-bas much better reproduces the quadrupole deformation and energy of the isoscalar giant quadrupole resonance. The accuracy of SRPA is justified by comparison with exact RPA. The calculations suggest that a further development of the self-consistent calculation schemes is needed for a systematic satisfactory description of the 2γ+ states.

  6. Octupole Deformation Bands of πh11/2 in Neutron-Rich 145,147La Nuclei

    NASA Astrophysics Data System (ADS)

    Zhu, Sheng-jiang; S, Zhu J.; Wang, Mu-ge; J, Hamilton H.; A, Ramayya V.; B, Babu R. S.; W, Ma C.; Long, Gui-lu; Zhu, Ling-yan; Li, Ming; A, Sakhaee; Gan, Cui-yun; Yang, Li-ming; J, Komicki; J, Cole D.; R, Aryaeinejad; M, Drigert W.; J, Rasmussen O.; M, Stoyer A.; S, Chu Y.; K, Gregorich E.; M, Mohar F.; S, Prussin G.; I, Lee Y.; Yu, Oganessian Ts; G, Ter-Akopian M.; A, Daniel V.

    1999-03-01

    Octupole deformation bands built on πh11/2 orbital in neutron-rich odd-Z 145,147La nuclei have been investigated by measuring the prompt γ-rays emitted from the 252Cf source. The alternating parity band structures and strong E1 transitions observed between negative- and positive-parity bands in both nuclei indicate the octupole deformation enhanced by the h11/2 single proton coupling. According to observed energy displacements the octupole deformation becomes stable at the intermediate spin states.

  7. Charge-exchange QRPA with the Gogny Force for Axially-symmetric Deformed Nuclei

    SciTech Connect

    Martini, M.; Goriely, S.; Péru, S.

    2014-06-15

    In recent years fully consistent quasiparticle random-phase approximation (QRPA) calculations using finite range Gogny force have been performed to study electromagnetic excitations of several axially-symmetric deformed nuclei up to the {sup 238}U. Here we present the extension of this approach to the charge-exchange nuclear excitations (pnQRPA). In particular we focus on the Isobaric Analog and Gamow-Teller resonances. A comparison of the predicted GT strength distribution with existing experimental data is presented. The role of nuclear deformation is shown. Special attention is paid to β-decay half-lives calculations for which experimental data exist and for specific isotone chains of relevance for the r-process nucleosynthesis.

  8. High energy collisions of strongly deformed nuclei: An old idea with a new twist

    SciTech Connect

    Shuryak, E. V.

    2000-03-01

    Collisions of deformed nuclei such as U may provide 40% more hard processes and about 30% larger energy densities, compared to central PbPb collisions. They also produce excited systems which are strongly deformed in the transverse plane, which are much larger than possible in peripheral PbPb collisions. We discuss how, even without a polarized target, one can study these phenomena by selecting particular events. Collisions are studied by a simple Monte Carlo model, and it is shown what can be achieved by making cuts in two control parameters--the number of participants and ellipticity. We also discuss how UU collisions may resolve a number of outstanding issues, from corrections to hard processes to elliptic flow (the existence of a quark-gluon plasma), to the mechanism of J/{psi} suppression. (c) 2000 The American Physical Society.

  9. Systematics of fine structure in the α decay of deformed odd-mass nuclei

    NASA Astrophysics Data System (ADS)

    Ren, Zhongzhou; Ni, Dongdong

    2014-12-01

    We present a detailed analysis of the a-decay fine structure in 32 deformed odd-mass nuclei from Z = 93 to Z = 102. The α-decay half-lives are systematically calculated within the multichannel cluster model (MCCM), which turns out to well reproduce the experimental data and show the neutron deformed shell structure. The branching ratios for various daughter states are investigated in the MCCM and in the WKB barrier penetration approach, respectively. It is found that the MCCM results agree well with the experimental data, while the WKB results have relatively large deviations from the experimental data for the α transitions to the high-lying members of the rotational band.

  10. Derivation of an optical potential for statically deformed rare-earth nuclei from a global spherical potential

    SciTech Connect

    Nobre, G. P. A.; Palumbo, A.; Herman, M.; Brown, D.; Hoblit, S.; Dietrich, F. S.

    2015-02-25

    The coupled-channel theory is a natural way of treating nonelastic channels, in particular those arising from collective excitations characterized by nuclear deformations. A proper treatment of such excitations is often essential to the accurate description of experimental nuclear-reaction data and to the prediction of a wide variety of scattering observables. Stimulated by recent work substantiating the near validity of the adiabatic approximation in coupled-channel calculations for scattering on statically deformed nuclei, we explore the possibility of generalizing a global spherical optical model potential (OMP) to make it usable in coupled-channel calculations on this class of nuclei. To do this, we have deformed the Koning-Delaroche global spherical potential for neutrons, coupling a sufficient number of states of the ground state band to ensure convergence. We present an extensive study of the effects of collective couplings and nuclear deformations on integrated cross sections as well as on angular distributions for neutron-induced reactions on statically deformed nuclei in the rare-earth region. We choose isotopes of three rare-earth elements (Gd, Ho, W), which are known to be nearly perfect rotors, to exemplify the results of the proposed method. Predictions from our model for total, elastic and inelastic cross sections, as well as for elastic and inelastic angular distributions, are in reasonable agreement with measured experimental data. In conclusion, these results suggest that the deformed Koning-Delaroche potential provides a useful regional neutron optical potential for the statically deformed rare earth nuclei.

  11. Evidence for the Importance of Soft Deformation Potentials in Strongly Deformed Nuclei

    SciTech Connect

    Pietralla, N.; Bonnet, J.; Beller, J.; Krugmann, A.; Moeller, O.; Costin, A.; Ai, H.; Casten, R. F.; Heinz, A.; McCutchan, E. A.; Qian, J.; Werner, V.; Rainovski, G.; Dusling, K.

    2009-01-28

    Excited states of {sup 168}Hf were populated using the {sup 124}Sn({sup 48}Ti,4n) fusion evaporation reaction at the WNSL of Yale University. The lifetimes of the J{sup {pi}} = 4{sup +},6{sup +},8{sup +}, and 10{sup +} levels along the ground state band of {sup 168}Hf were measured by means of the recoil distance Doppler shift (RDDS) method using the New Yale Plunger Device (NYPD) and the SPEEDY Ge detector array. The new lifetime values are sufficiently precise to clearly prove the increase of quadrupole collectivity as a function of angular momentum in the deformed nucleus {sup 168}Hf. The data agree with the predictions from the geometrical Confined {beta}-Soft (CBS) rotor model that involves centrifugal stretching in a soft potential. Relative and absolute E0 transition strengths [{rho}{sup 2}(E0)] on the transitional path between X(5) and the Rigid Rotor Limit have been evaluated within the framework of the CBS rotor model, too. Relative inter-band E0 transition strengths decrease with increasing angular momentum for a given potential stiffness, while for increasing potential stiffness, the absolute E0 transition strengths decrease with increasing angular momentum and increasing potential stiff0010ne.

  12. Non-Axial Octupole Deformations and Tetrahedral Symmetry in Heavy Nuclei

    SciTech Connect

    Mazurek, Katarzyna; Dudek, Jerzy

    2005-11-21

    The total energies of about 120 nuclei in the Thorium region have been calculated within the macroscopic-microscopic method in the 5-dimensional space of deformation parameters {alpha}20, {alpha}22, {alpha}30, {alpha}32 and {alpha}40. The macroscopic energy term contains the nuclear surface-curvature dependence as proposed within the LSD approach. The microscopic energies are calculated with the Woods-Saxon single particle potential employing the universal set of parameters.We study a possible presence of the octupole axial and non-axial degrees of freedom all-over in the ({beta}, {gamma})-plane focussing on the ground-states, secondary minima and in the saddle points. In fact, a competition between axial and tri-axial octupole deformation parameters is obtained at the saddle points and in the secondary minima for many isotones with N > 136. The presence of the tetrahedral symmetry minima is predicted in numerous nuclei in the discussed region, although most of the time at relatively high excitation energies.

  13. Deformed rotational bands in the doubly odd nuclei [sup 134]Pr and [sup 132]Pr

    SciTech Connect

    Hauschild, K.; Wadsworth, R.; Clark, R.M.; Hibbert, I.M. ); Beausang, C.W.; Forbes, S.A.; Nolan, P.J.; Paul, E.S.; Semple, A.T.; Wilson, J.N. ); Gizon, A.; Gizon, J.; Santos, D. ); Simpson, J. )

    1994-08-01

    The nuclei [sup 132,134]Pr have been investigated using the [sup 100]Mo([sup 37]Cl,[ital xn]) reactions at a beam energy of 155 MeV. Gamma rays were detected with the Eurogam array. Analysis of the data has revealed the presence of two new weakly populated decoupled bands in [sup 134]Pr. One of these bands has been linked into the normal-deformed states and is thought to be built on a [pi]([ital h][sub 11/2])[sup 2][direct product][nu]([ital f][sub 7/2],[ital h][sub 9/2]) configuration. The second band has been interpreted as being based on a [pi]([ital h][sub 11/2])[sup 3][direct product][nu][ital i][sub 13/2] intruder configuration within the second [beta][sub 2][congruent]0.3 prolate minimum. The known decoupled band in [sup 132]Pr (5[ital n] reaction channel) and the highly deformed band in [sup 130]La A([alpha]3[ital n]) have also been extended. The structure of all of these bands is discussed together with similar bands in nieghboring odd-odd nuclei.

  14. Fragmentation of two-phonon {gamma}-vibrational strength in deformed nuclei

    SciTech Connect

    Wu, C.Y.; Cline, D.

    1996-12-31

    Rotational and vibrational modes of collective motion. are very useful in classifying the low-lying excited states in deformed nuclei. The rotational mode of collective motion is characterized by rotational bands having correlated level energies and strongly-enhanced E2 matrix elements. The lowest intrinsic excitation with I,K{sup {pi}} = 2,2{sup +} in even-even deformed nuclei, typically occurring at {approx}1 MeV, is classified as a one-phonon {gamma}-vibration state. In a pure harmonic vibration limit, the expected two-phonon {gamma}-vibration states with I,K{sup {pi}} = 0,0{sup +} and 4,4{sup +} should have excitation energies at twice that of the I,K{sup {pi}} = 2,2{sup +} excitation, i.e. {approx}2 MeV, which usually is above the pairing gap leading to possible mixing with two-quasiparticle configurations. Therefore, the question of the localization of two-phonon {gamma}-vibration strength has been raised because mixing may lead to fragmentation of the two-phonon strength over a range of excitation energy. For several well-deformed nuclei, an assignment of I,K{sup {pi}}=4,4{sup +} states as being two-phonon vibrational excitations has been suggested based on the excitation energies and the predominant {gamma}-ray decay to the I,K{sup {pi}}=2,2{sup +} state. However, absolute B(E2) values connecting the presumed two- and one-phonon states are the only unambiguous measure of double phonon excitation. Such B(E2) data are available for {sup 156}Gd, {sup 160}Dy, {sup 168}Er, {sup 232}Th, and {sup 186,188,190,192}Os. Except for {sup 160}Dy, the measured B(E2) values range from 2-3 Weisskopf units in {sup 156}Gd to 10-20 Weisskopf units in osmium nuclei; enhancement that is consistent with collective modes of motion.

  15. Octupole deformation in the ground states of even-even Z ˜96 , N ˜196 actinides and superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Agbemava, S. E.; Afanasjev, A. V.

    2017-08-01

    A systematic search for axial octupole deformation in the actinides and superheavy nuclei with proton numbers Z =88 -126 and neutron numbers from the two-proton drip line up to N =210 was performed in covariant density functional theory (DFT) using four state-of-the-art covariant energy density functionals representing different model classes. The nuclei in the Z ˜96 , N ˜196 region of octupole deformation were investigated in detail and the systematic uncertainties in the description of their observables were quantified. A similar region of octupole deformation exists also in Skyrme DFT and microscopic+macroscopic approaches but it is centered at somewhat different particle numbers. Theoretical uncertainties in the predictions of the regions of octupole deformation increase on going to superheavy nuclei with Z ˜120 , N ˜190 . There are no octupole deformed nuclei for Z =112 -126 in covariant DFT calculations. This agrees with Skyrme DFT calculations, but disagrees with Gogny DFT and microscopic+macroscopic calculations which predict an extended Z ˜120 , N ˜190 region of octupole deformation.

  16. A ΔE-E semiconductor detector combined with CsI(Tl) crystal for monitoring the relative electrons flux generated in interaction of accelerated nuclei beam on thin targets

    NASA Astrophysics Data System (ADS)

    Cruceru, M.; Afanasiev, S.; Dryablov, D.; Dubinchik, B.; Igamkulov, Z.

    2015-07-01

    Experimental data are presented, obtained with a ΔE-E semiconductor detector combined with a CsI(Tl) inorganic scintillator crystal. The interaction between a beam of accelerated nuclei and thin targets is analyzed. We show that, as a result of this interaction, the secondary particles, including δ-electrons, are generated. In the case of δ-electrons it is possible to study the beam characteristics and the nature of interaction processes, which is of great interest in high-energy interaction.

  17. Deformation signature from the Gamow-Teller decay of N=Z nuclei

    SciTech Connect

    Miehe, Ch.; Dessagne, Ph.; Huck, A.; Knipper, A.; Marguier, G.; Longour, C.; Rauch, V.; Giovinazzo, J.; Borge, M. J. G.; Piqueras, I.; Tengblad, O.; Jokinen, A.; Ramdhane, M.

    1998-12-21

    The {sup 76}Sr (N=Z=38) and the {sup 72}Kr (N=Z=36) {beta}{sup +} EC decay have been studied at the CERN/ISOLDE PSB facility where their beta-gamma and delayed particle decay modes have been investigated. The established decay schemes yield new information on the Gamow-Teller (GT) strength spread over the J{sup {pi}}=1{sup +} states in the daughter nuclei. The delayed proton emission of an N=Z nucleus is observed for the first time in the case of {sup 76}Sr. The experimental GT strength intensities and distributions are discussed in the light of the theoretical estimates for oblate and prolate deformations.

  18. Theory of (3He,(alpha)) surrogate reactions for deformed uranium nuclei

    SciTech Connect

    Thompson, I; Escher, J E

    2006-11-08

    We present the one-step theory of neutron-pickup transfer reactions with {sup 3}He projectiles on {sup 235}U and {sup 238}U. We find all the neutron eigenstates in a deformed potential, and use those in a given energy range for ({sup 3}He, {alpha}) DWBA pickup calculations to find the spin and parity distributions of the residual target nuclei. A simple smoothing convolution is used to take into account the spreading width of the single-neutron hole states into the more complicated compound nuclear states. We assume that the initial target is an even-even rotor, but can take into account spectator neutrons outside such a rotor by recombining their spin and parity at the end of the calculations.

  19. 2-D Hartee-Fock-Bogoliubov Calculations For Exotic Deformed Nuclei

    NASA Astrophysics Data System (ADS)

    Blazkiewicz, Artur; Oberacker, Volker E.; Umar, Sait A.; Teran, Edgar

    2003-10-01

    We solve the Hartree-Fock-Bogoliubov (HFB) equations in coordinate space; the computational method has been specifically designed to study ground state properties of nuclei near the neutron and proton drip lines teref1. The unique feature of our code is that it takes into account the strong coupling to high-energy continuum states, up to an equivalent single-particle energy of 60 MeV or higher. We solve the HFB equations for deformed, axially symmetric even-even nuclei in coordinate space on a 2-D lattice with Basis-Spline methods. For the p-h channel, the Skyrme (SLy4) effective N-N interaction is utilized, and for the p-p and h-h channel we use a delta interaction. Results teref2,ref3 are presented for binding energies, deformations, normal densities and pairing densities, Fermi levels, and pairing gaps. In particular, we calculate the properties of two light isotope chains up to the two-neutron dripline: oxygen (^22-28O) and sulfur (^40-52S). For some of the sulfur isotopes we found the "shape coexistence" what was also confirmed by RMF calculations of P. Ring and G.A. Lalazissis teref4. Furthermore, we study the strongly deformed heavy systems zirconium (^102,104Zr), cerium (^152Ce), and samarium (^158Sm).We are also planning to study other isotopes by running our new parallel MPI version of HFB code. Comparison with relativistic mean field theory and with experimental data is given whenever available. This work has been supported by the U.S. Department of Energy under grant No. DE-FG02-96ER40963 with Vanderbilt University. The numerical calculations were carried out on the IBM-RS/6000 SP supercomputer at NERSC in Berkeley and on our local "Beowulf" Vampire computer at Vanderbilt University. 99 ref1 Axially Symmetric Hartee-Fock-Bogoliubov calculations for nuclei near the drip lines,E. Teran, V.E. Oberacker and A.S. Umar, Phys. Rev. C 67, (June 2003) ref2 Half lives of isomeric states from SF of ^252Cf and large deformations in ^104Zr and ^158Sm, J.K. Hwang, A

  20. Half-lives and fine structure for the α decay of deformed even-even nuclei

    NASA Astrophysics Data System (ADS)

    Ni, DongDong; Ren, ZhongZhou

    2011-08-01

    The α-decay properties of well-deformed even-even nuclei are systematically calculated within the multichannel cluster model (MCCM). Instead of working in the WKB framework, the quasibound solution to the coupled Schrödinger equation is presented with outgoing wave boundary conditions, and the coupling potential is taken into full account in terms of the general quantum theories. The calculated α-decay half-lives are found to agree well with the experimental data with a mean factor of less than 2. The fine structure observed in α decay is also well reproduced by the four-channel microscopic calculation. Very strikingly, the MCCM can give relatively precise descriptions of the branching ratio to excited 4+ states, which is often overestimated in the usual WKB calculations. We expect it to be a significant development of theoretical models toward quantitative descriptions of α transitions to high-spin daughter states.

  1. New exact solutions of the standard pairing model for well-deformed nuclei

    SciTech Connect

    Pan Feng; Xie Mingxia; Guan Xin; Dai Lianrong; Draayer, J. P.

    2009-10-15

    A new step-by-step diagonalization procedure for evaluating exact solutions of the nuclear deformed mean-field plus pairing interaction model is proposed via a simple Bethe ansatz in each step from which the eigenvalues and corresponding eigenstates can be obtained progressively. This new approach draws upon an observation that the original one- plus two-body problem in a k-particle Hilbert subspace can be mapped onto a one-body grand hard-core boson picture that can be solved step by step with a simple Bethe ansatz known from earlier work. Based on this new procedure, it is further shown that the extended pairing model for deformed nuclei [Feng Pan, V. G. Gueorguiev, and J. P. Draayer, Phys. Rev. Lett. 92, 112503 (2004)] is similar to the standard pairing model with the first step approximation, in which only the lowest energy eigenstate of the standard pure pairing interaction part is taken into consideration. Our analysis shows that the standard pairing model with the first step approximation displays similar pair structures of the first few exact low-lying states of the model, which, therefore, provides a link between the two models.

  2. Derivation of an optical potential for statically deformed rare-earth nuclei from a global spherical potential

    DOE PAGES

    Nobre, G. P. A.; Palumbo, A.; Herman, M.; ...

    2015-02-25

    The coupled-channel theory is a natural way of treating nonelastic channels, in particular those arising from collective excitations characterized by nuclear deformations. A proper treatment of such excitations is often essential to the accurate description of experimental nuclear-reaction data and to the prediction of a wide variety of scattering observables. Stimulated by recent work substantiating the near validity of the adiabatic approximation in coupled-channel calculations for scattering on statically deformed nuclei, we explore the possibility of generalizing a global spherical optical model potential (OMP) to make it usable in coupled-channel calculations on this class of nuclei. To do this, wemore » have deformed the Koning-Delaroche global spherical potential for neutrons, coupling a sufficient number of states of the ground state band to ensure convergence. We present an extensive study of the effects of collective couplings and nuclear deformations on integrated cross sections as well as on angular distributions for neutron-induced reactions on statically deformed nuclei in the rare-earth region. We choose isotopes of three rare-earth elements (Gd, Ho, W), which are known to be nearly perfect rotors, to exemplify the results of the proposed method. Predictions from our model for total, elastic and inelastic cross sections, as well as for elastic and inelastic angular distributions, are in reasonable agreement with measured experimental data. In conclusion, these results suggest that the deformed Koning-Delaroche potential provides a useful regional neutron optical potential for the statically deformed rare earth nuclei.« less

  3. Parameterization of deformed nuclei for Glauber modeling in relativistic heavy ion collisions

    DOE PAGES

    Sorensen, P.; Tang, A. H.; Videbaek, F.; ...

    2015-08-04

    In this study, the density distributions of large nuclei are typically modeled with a Woods–Saxon distribution characterized by a radius R0 and skin depth a. Deformation parameters β are then introduced to describe non-spherical nuclei using an expansion in spherical harmonics R0(1+β2Y20+β4Y40). But when a nucleus is non-spherical, the R0 and a inferred from electron scattering experiments that integrate over all nuclear orientations cannot be used directly as the parameters in the Woods–Saxon distribution. In addition, the β2 values typically derived from the reduced electric quadrupole transition probability B(E2)↑ are not directly related to the β2 values used in themore » spherical harmonic expansion. B(E2)↑ is more accurately related to the intrinsic quadrupole moment Q0 than to β2. One can however calculate Q0 for a given β2 and then derive B(E2)↑ from Q0. In this paper we calculate and tabulate the R0, a , and β2 values that when used in a Woods–Saxon distribution, will give results consistent with electron scattering data. We then present calculations of the second and third harmonic participant eccentricity (ε2 and ε3) with the new and old parameters. We demonstrate that ε3 is particularly sensitive to a and argue that using the incorrect value of a has important implications for the extraction of viscosity to entropy ratio (η/s) from the QGP created in Heavy Ion collisions.« less

  4. The shell model Monte Carlo approach to level densities: from medium-mass to heavy deformed nuclei

    SciTech Connect

    Alhassid, Y.

    2008-04-17

    The shell model Monte Carlo (SMMC) approach is a powerful state-of-the-art method for the microscopic calculation of level densities in the presence of correlations. With this method it is possible to perform realistic calculations in model spaces that are many orders of magnitude larger than spaces that can be treated with conventional diagonalization methods. SMMC level densities of medium-mass nuclei were found to be in remarkably good agreement with experimental level densities without any adjustable parameters. We discuss recent developments, including a spin projection method for calculating the spin distribution of level densities and the extension of SMMC to heavy deformed nuclei.

  5. Alpha-decay of deformed superheavy nuclei as a probe of shell closures

    NASA Astrophysics Data System (ADS)

    Ismail, M.; Seif, W. M.; Adel, A.; Abdurrahman, A.

    2017-02-01

    A systematic study on α-decay half-life time, Tα, of α-particle emission from a large number of deformed heavy and superheavy nuclei is presented. The calculations are employed in the framework of the density-dependent cluster model. The microscopic α-daughter nuclear interaction potential is calculated in the framework of the double-folding model with the realistic effective Michigan-three-Yukawa Reid nucleon-nucleon interaction. We study the neutron number variation of log Tα and arranged different isotones at each neutron magic number according to their stability, in the sense that the more stable isotone corresponds to the lowest value of log Tα. We found that the half-life time becomes minimum when the neutron or proton numbers of the corresponding daughter nucleus are magic. Moreover, the half-life time is maximum for parent nucleus with magicity. The nuclear stability is assumed to be proportional with the depth of the minimum value in log Tα for the daughter nucleus or the height of its maximum value for the parent one. The neutron magic numbers predicted and confirmed from the present study are 126, 152, 162, 172, 184, 196, 202 and 212, most of them were deduced by other authors based on different methods.

  6. Description of proton radioactivity using the Coulomb and proximity potential model for deformed nuclei

    NASA Astrophysics Data System (ADS)

    Santhosh, K. P.; Sukumaran, Indu

    2017-09-01

    Half-life predictions have been performed for the proton emitters with Z >50 in the ground state and isomeric state using the Coulomb and proximity potential model for deformed nuclei (CPPMDN). The agreement of the calculated values with the experimental data made it possible to predict some proton emissions that are not verified experimentally yet. For a comparison, the calculations also are performed using other theoretical models, such as the Gamow-like model of Zdeb et al. [Eur. Phys. J. A 52, 323 (2016), 10.1140/epja/i2016-16323-7], the semiempirical relation of Hatsukawa et al. [Phys. Rev. C 42, 674 (1990), 10.1103/PhysRevC.42.674], and the CPPM of Santhosh et al. [Pramana 58, 611 (2002)], 10.1007/s12043-002-0019-2. The Geiger-Nuttall law, originally observed for α decay, studied for proton radioactivity is found to work well provided it is plotted for the isotopes of a given proton emitter nuclide with the same ℓ value. The universal curve is found to be valid for proton radioactivity also as we obtained a single straight line for all proton emissions irrespective of the parents. Through the analysis of the experimentally measured half-lives of 44 proton emitters, the study revealed that the present systematic study lends support to a unified description for studying α decay, cluster radioactivity, and proton radioactivity.

  7. SU(3) gauge symmetry for collective rotational states in deformed nuclei

    NASA Astrophysics Data System (ADS)

    Rosensteel, George; Sparks, Nick

    2016-09-01

    How do deformed nuclei rotate? The qualitative answer is that a velocity-dependent interaction causes a strong coupling between the angular momentum and the vortex momentum (or Kelvin circulation). To achieve a quantitative explanation, we propose a significant extension of the Bohr-Mottelson legacy model in which collective wave functions are vector-valued in an irreducible representation of SU(3). This SU(3) is not the usual Elliott choice, but rather describes internal vorticity in the rotating frame. The circulation values C of an SU(3) irreducible representation, say the (8,0) for 20Ne, are C = 0, 2, 4, 6, 8, which is the same as the angular momentum spectrum in the Elliott model; the reason is a reciprocity theorem in the symplectic model. The differential geometry of Yang-Mills theory provides a natural mathematical framework to solve the angular-vortex coupling riddle. The requisite strong coupling is a ``magnetic-like'' interaction arising from the covariant derivative and the bundle connection. The model builds on prior work about the Yang-Mills SO(3) gauge group model.

  8. Dirac-Hartree-Bogoliubov calculation for spherical and deformed hot nuclei: Temperature dependence of the pairing energy and gaps, nuclear deformation, nuclear radii, excitation energy, and entropy

    NASA Astrophysics Data System (ADS)

    Lisboa, R.; Malheiro, M.; Carlson, B. V.

    2016-02-01

    Background: Unbound single-particle states become important in determining the properties of a hot nucleus as its temperature increases. We present relativistic mean field (RMF) for hot nuclei considering not only the self-consistent temperature and density dependence of the self-consistent relativistic mean fields but also the vapor phase that takes into account the unbound nucleon states. Purpose: The temperature dependence of the pairing gaps, nuclear deformation, radii, binding energies, entropy, and caloric curves of spherical and deformed nuclei are obtained in self-consistent RMF calculations up to the limit of existence of the nucleus. Method: We perform Dirac-Hartree-Bogoliubov (DHB) calculations for hot nuclei using a zero-range approximation to the relativistic pairing interaction to calculate proton-proton and neutron-neutron pairing energies and gaps. A vapor subtraction procedure is used to account for unbound states and to remove long range Coulomb repulsion between the hot nucleus and the gas as well as the contribution of the external nucleon gas. Results: We show that p -p and n -n pairing gaps in the S10 channel vanish for low critical temperatures in the range Tcp≈0.6 -1.1 MeV for spherical nuclei such as 90Zr, 124Sn, and 140Ce and for both deformed nuclei 150Sm and 168Er. We found that superconducting phase transition occurs at Tcp=1.03 Δp p(0 ) for 90Zr, Tcp=1.16 Δp p(0 ) for 140Ce, Tcp=0.92 Δp p(0 ) for 150Sm, and Tcp=0.97 Δp p(0 ) for 168Er. The superfluidity phase transition occurs at Tcp=0.72 Δn n(0 ) for 124Sn, Tcp=1.22 Δn n(0 ) for 150Sm, and Tcp=1.13 Δn n(0 ) for 168Er. Thus, the nuclear superfluidity phase—at least for this channel—can only survive at very low nuclear temperatures and this phase transition (when the neutron gap vanishes) always occurs before the superconducting one, where the proton gap is zero. For deformed nuclei the nuclear deformation disappear at temperatures of about Tcs=2.0 -4.0 MeV , well above the

  9. Interplay of collective and single-particle properties of excited states of deformable odd nuclei {sup 155}Eu and {sup 161}Tm

    SciTech Connect

    Sharipov, Sh.; Ermamatov, M. J. Bayimbetova, J. K.

    2008-02-15

    The properties of excited states of two deformable odd nuclei are investigated within the nonadiabatic model previously developed by the present authors. The results of relevant calculations are compared with available experimental data.

  10. Systematics of ground-state quadrupole moments of odd-A deformed nuclei determined with muonic M x rays

    SciTech Connect

    Tanaka, Y.; Steffen, R.M.; Shera, E.B.; Reuter, W.; Hoehn, M.V.; Zumbro, J.D.

    1984-05-01

    The ground-state quadrupole moments of /sup 151/Eu, /sup 153/Eu, /sup 159/Tb, /sup 163/Dy, /sup 167/Er, /sup 177/Hf, /sup 179/Hf, /sup 191/Ir, and /sup 193/Ir were determined by measuring the quadrupole hyperfine-splitting energies of muonic M x rays. The results are Q = 0.903(10) e b for /sup 151/Eu, Q = 2.412(21) e b for /sup 153/Eu, Q = 1.432(8) e b for /sup 159/Tb, Q = 2.648(21) e b for /sup 163/Dy, Q = 3.565(29) e b for /sup 167/Er, Q = 3.365(29) e b for /sup 177/Hf, Q = 3.793(33) e b for /sup 179/Hf, Q = 0.816(9) e b for /sup 191/Ir, and Q = 0.751(9) e b for /sup 193/Ir. The present quadrupole moments, compared with values obtained from electronic-atom hyperfine measurements, show that the Sternheimer correction factors used in the rare-earth electronic-atom analysis are unreliable. Systematics of deformation parameters ..beta../sub 2/ calculated from the present quadrupole moments for odd-A nuclei, and from B(E2) values of Coulomb excitation measurements for even-A nuclei, also indicate that the largest deformation change so far known exists between /sup 151/Eu and /sup 153/Eu. Except at the onset of nuclear deformation, the deformation parameters of the odd-A nuclei are quite consistent with those of the even-A neighbors.

  11. A C-code for the double folding interaction potential for reactions involving deformed target nuclei

    NASA Astrophysics Data System (ADS)

    Gontchar, I. I.; Chushnyakova, M. V.

    2013-01-01

    We present a C-code designed to obtain the interaction potential between a spherical projectile nucleus and an axial-symmetrical deformed target nucleus and in particular to find the Coulomb barrier, by using the double folding model (DFM). The program calculates the nucleus-nucleus potential as a function of the distance between the centers of mass of colliding nuclei as well as of the angle between the axis of symmetry of the target nucleus and the beam direction. The most important output parameters are the Coulomb barrier energy and the radius. Since many researchers use a Woods-Saxon profile for the nuclear term of the potential we provide an option in our code for fitting the DFM potential by such a profile near the barrier. Program summaryProgram title: DFMDEF Catalogue identifier: AENI_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AENI_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 2245 No. of bytes in distributed program, including test data, etc.: 215442 Distribution format: tar.gz Programming language: C. Computer: PC, Mac. Operating system: Windows XP (with the GCC-compiler version 2), MacOS, Linux. RAM: 100 MB with average parameters set Classification: 17.9. Nature of problem: The code calculates in a semimicroscopic way the bare interaction potential between a spherical projectile nucleus and a deformed but axially symmetric target nucleus as a function of the center of mass distance as well as of the angle between the axis of symmetry of the target nucleus and the beam direction. The height and the position of the Coulomb barrier are found. The calculated potential is approximated by a conventional Woods-Saxon profile near the barrier. Dependence of the barrier parameters upon the characteristics of the effective NN forces (like, e

  12. Unified description of the double {beta} decay to the first quadrupole phonon state in spherical and deformed nuclei

    SciTech Connect

    Raduta, C. M.; Raduta, A. A.

    2007-10-15

    The Gamow-Teller transition operator is written as a polynomial in the dipole proton-neutron and quadrupole charge-conserving quasiparticle random-phase approximation boson operators, using the prescription of the boson expansion technique. Then, the 2{nu}{beta}{beta} process ending on the first 2{sup +} state in the daughter nucleus is allowed through one-, two-, and three-boson states describing the odd-odd intermediate nucleus. The approach uses a single particle basis that is obtained by projecting out the good angular momentum from an orthogonal set of deformed functions. The basis for mother and daughter nuclei may have different deformations. The GT transition amplitude as well as the half-lives were calculated for 18 transitions. Results are compared with the available data as well as with the predictions obtained with other methods.

  13. Shape of {sup 44}Ar: Onset of deformation in neutron-rich nuclei near {sup 48}Ca

    SciTech Connect

    Zielinska, M.; Goergen, A.; Clement, E.; Korten, W.; Dossat, C.; Ljungvall, J.; Obertelli, A.; Theisen, Ch.; Delaroche, J.-P.; Girod, M.; Buerger, A.; Catford, W.; Iwanicki, J.; Napiorkowski, P. J.; Srebrny, J.; Wrzosek, K.; Libert, J.; Rodriguez-Guzman, R.; Sletten, G.

    2009-07-15

    The development of deformation and shape coexistence in the vicinity of doubly magic {sup 48}Ca, related to the weakening of the N=28 shell closure, was addressed in a low-energy Coulomb excitation experiment using a radioactive {sup 44}Ar beam from the SPIRAL facility at GANIL. The 2{sub 1}{sup +} and 2{sub 2}{sup +} states in {sup 44}Ar were excited on {sup 208}Pb and {sup 109}Ag targets at two different beam energies. B(E2) values between all observed states and the spectroscopic quadrupole moment of the 2{sub 1}{sup +} state were extracted from the differential Coulomb excitation cross sections, indicating a prolate shape of the {sup 44}Ar nucleus and giving evidence of an onset of deformation already two protons and two neutrons away from doubly magic {sup 48}Ca. New Hartree-Fock-Bogoliubov based configuration mixing calculations have been performed with the Gogny D1S interaction for {sup 44}Ar and neighboring nuclei using two different approaches: the angular momentum projected generator coordinate method considering axial quadrupole deformations and a five-dimensional approach including the triaxial degree of freedom. The experimental values and new calculations are furthermore compared to shell-model calculations and to relativistic mean-field calculations. The new results give insight into the weakening of the N=28 shell closure and the development of deformation in this neutron-rich region of the nuclear chart.

  14. Reaction cross-section calculations using new experimental and theoretical level structure data for deformed nuclei

    SciTech Connect

    Hoff, R.W.; Gardner, D.G.; Gardner, M.A.

    1985-05-01

    A technique for modeling level structures of odd-odd nuclei has been used to construct sets of discrete states with energies in the range 0 to 1.5 MeV for several nuclei in the rare-earth and actinide regions. The accuracy of the modeling technique was determined by comparison with experimental data. Examination was made of what effect the use of these new, more complete sets of discrete states has on the calculation of level densities, total reaction cross sections, and isomer ratios. 9 refs.

  15. Tensor Part of the Skyrme Energy Density Functional. II: Deformation Properties of Magic and Semi-Magic Nuclei

    SciTech Connect

    Bender, M.; Bennaceur, K.; Duguet, T.; Heenen, P.-H.; Lesinski, Thomas; Meyer, J.

    2009-01-01

    We study systematically the impact of the time-even tensor terms of the Skyrme energy density functional, i.e., terms bilinear in the spin-current tensor density, on deformation properties of closed-shell nuclei corresponding to 20, 28, 40, 50, 82, and 126 neutron or proton shell closures. We compare results obtained with three different families of Skyrme parameterizations whose tensor terms have been adjusted on properties of spherical nuclei(i)TIJ interactions proposed in the first paper of this series [T. Lesinski et al., Phys. Rev. C 76, 014312 (2007)] which were constructed through a complete readjustment of the rest of the functional (ii) parameterizations whose tensor terms have been added perturbatively to existing Skyrme interactions, with or without readjusting the spin-orbit coupling constant. We analyze in detail the mechanisms at play behind the impact of tensor terms on deformation properties and how studying the latter can help screen out unrealistic parameterizations. It is expected that findings of the present paper are, to a large extent, independent of remaining deficiencies of the central and spin-orbit interactions, and will be of great value for the construction of future improved energy functionals.

  16. Deformed shell model results for neutrinoless positron double beta decay of nuclei in the A = 60-90 region

    NASA Astrophysics Data System (ADS)

    Sahu, R.; Srivastava, P. C.; Kota, V. K. B.

    2013-09-01

    Nuclear transition matrix elements (NTME) for neutrinoless positron double beta decay (0νβ+β+ and 0νβ+EC) of 64Zn, 74Se, 78Kr and 84Sr nuclei, which are in the A = 60-90 region, are calculated within the framework of the deformed shell model (DSM) based on Hartree-Fock states. For 64Zn, GXPF1A interaction in 1f7/2, 2p3/2, 1f5/2 and 2p1/2 space with 40Ca as the core is employed. Similarly for 74Se, 78Kr and 84Sr nuclei, 56Ni is taken as the inert core employing a modified Kuo interaction in 2p3/2, 1f5/2, 2p1/2 and 1g9/2 space. After ensuring that the DSM gives a good description of the spectroscopic properties of low-lying levels in the four nuclei considered, the NTME are calculated. The half-lives deduced with these NTME, assuming the neutrino mass is 1 eV, are smallest for 78Kr with the half-life for β+EC decay being ˜1027 yr. For all others, the half-lives are in the range of ˜1028-1029 yr.

  17. Study of short-range correlation in nuclei via measurement of the 4He(,ee'pp) and 4He(e,e'pn) reaction

    SciTech Connect

    Korover, Igor

    2015-04-01

    This thesis reports on a simultaneous measurement of the 4He(e,e'p), 4He(e,e'pp), and 4He(e,e'pn) reactions at Q2 = 2 (GeV/c)2 and xB > 1 for an (e,e'p) missing momentum range of 400 to 830 MeV/c.

  18. A study of Gamow-Teller transitions for N = Z nuclei, 24Mg, 28Si, and 32S, by a deformed QRPA

    NASA Astrophysics Data System (ADS)

    Ha, Eunja; Cheoun, Myung-Ki

    2017-02-01

    We investigated Gamow-Teller (GT) transitions and strength distributions of s- d shell N = Z nuclei, 24Mg, 28Si, and 32S, by a deformed quasi-particle random phase approximation (DQRPA). In the DQRPA, we included particle model space up to p- f shell and considered explicitly the deformation as well as the like- and unlike-pairing correlations. Shell evolution by deformation and attractive force by unlike-pairing correlations turned out to play vital roles to reproduce the experimental GT data. Correlations between the deformation and the pairing correlations are also discussed with the comparison to the experimental data shape.

  19. In search of a broader microscopic underpinning of the potential energy surface in heavy deformed nuclei

    NASA Astrophysics Data System (ADS)

    Hess, P. O.; Ermamatov, M.

    2017-07-01

    Starting from the content of the shell model space and using a simple symplectic as a weight Hamiltonian, the relative positions of different symplectic irreducible representations are deduced. Applying a geometrical mapping leads to a microscopically derived Potential-Energy-Surface. After smoothing this surface and fitting a mass parameter to the first excited 6+-state in the ground state band, the spectrum of a nucleus can be reproduced qualitatively. The method is also used to obtain a first estimation of the quadrupole Potential Energy Surface of any nucleus, allowing to obtain information about the structure of the nucleus in question. Of special interest is the prediction of the structure of nuclei away from the valley of stability and of super-heavy nuclei. The method will be illustrated at184W. One objective is to show that the Pauli Exclusion Principle is the main driving force for the structure of a nucleus, though some further microscopic input has to be used.

  20. The emergence of deformation and rotational states in the many-nucleon quantum theory of nuclei

    NASA Astrophysics Data System (ADS)

    Rowe, D. J.

    2016-02-01

    The many-nucleon quantum mechanics of a nucleus is infinite-dimensional and, although simply defined, it has the potential for unlimited complexity. Nevertheless, the low-energy states of heavy open-shell nuclei exhibit properties that are remarkably well described by simple collective models. This paper examines this emergent simplicity from a perspective that closely parallels the emergence of shell structure in the Mayer-Jensen model. The result is an expression of the many-nucleon Hilbert space of a nucleus as an energy-ordered sum of subspaces each of which carries a microscopic version of the Bohr-Mottelson unified model. Each of the subspaces is characterized by nuclear states with a common intrinsic shape defined by its quadrupole moments. An emergence of simplicity and shape-coexistence in nuclei is then explained if it can be demonstrated that there is a relatively small and coherent mixing of the states of different collective subspaces.

  1. Search for the Tri-Axial Hexadecapole-Deformation Effects in Trans-Actinidae Nuclei

    NASA Astrophysics Data System (ADS)

    Dudek, J.; Mazurek, K.; Nerlo-Pomorska, B.

    We have performed calculations of the nuclear potential energies in a 5-dimensional space of deformation parameters including α20, α22, α40, α42 and α44 multipole deformations by using the macroscopic-microscopic method. The energy expression contains the macroscopic term (in our case in the form of the Lublin Strasbourg Drop - LSD) and the microscopic terms of the Strutinsky shell energy and projected BCS pairing energy. The single-particle energies are obtained from the classical mean-field potential as well as from the correspondig Dirac relativistic realisation of the mean-field, both parametrised with the help of the deformed Woods-Saxon forms. Our resuls are compared to the selfconsistent Hartree Fock Bogolubov method with the D1S Gogny force.

  2. Level densities and barriers of deformed 59Cu nuclei with 28ħ<=Jav<=34ħ

    NASA Astrophysics Data System (ADS)

    Fornal, B.; Prete, G.; Nebbia, G.; Trotti, F.; Viesti, G.; Fabris, D.; Hagel, K.; Natowitz, J. B.

    1988-06-01

    The spectra of α particles emitted from narrow windows of angular momentum with 28ħ<=Jav<=34ħ show systematic deviations from spectra calculated using the statistical model as the spin of the emitter increases to values for which strong deformations are predicted. The barrier reduction and the enhancement of the level density needed to reproduce the experimental spectra have been determined.

  3. Total and partial capture cross sections in reactions with deformed nuclei at energies near and below the Coulomb barrier

    SciTech Connect

    Kuzyakin, R. A. Sargsyan, V. V.; Adamian, G. G.; Antonenko, N. V.

    2013-06-15

    Within the quantum diffusion approach, the capture of a projectile nucleus by a target nucleus is studied at bombarding energies above and below the Coulomb barrier. The effects of deformation of interacting nuclei and neutron transfer between them on the total and partial capture cross sections and the mean angular momentum of the captured system are studied. The results obtained for the {sup 16}O + {sup 112}Cd, {sup 152}Sm, and {sup 184}W; {sup 19}F +{sup 175}Lu; {sup 28}Si +{sup 94,100}Mo and {sup 154}Sm; {sup 40}Ca +{sup 96}Zr; {sup 48}Ca+ {sup 90}Zr; and {sup 64}Ni +{sup 58,64}Ni, {sup 92,96}Zr, and {sup 100}Mo reactions are in good agreement with available experimental data.

  4. Correlating double-difference of charge radii with quadrupole deformation and B (E 2 ) in atomic nuclei

    NASA Astrophysics Data System (ADS)

    Sun, B. H.; Liu, C. Y.; Wang, H. X.

    2017-01-01

    A good linear correlation is found between the double-difference of charge radius δ R2 p -2 n(Z ,N ) with that of quadrupole deformation data in even-even nuclei. This results in a further improved charge radius relation that holds in a precision of about 5 ×10-3 fm. The new relation can be generalized to the reduced electric quadrupole transition probability B (E 2 ) between the first 2+ state and the 0+ ground state, and the mean lifetime τ of the first 2+ state. Same correlations are also seen in global nuclear models such as Hartree-Fock-Bogoliubov (HFB-24) and relativistic mean field (RMF); however, they are not consistent with the experimental data.

  5. Selection rules for electromagnetic transitions in triaxially deformed odd-A nuclei

    SciTech Connect

    Tanabe, Kosai; Sugawara-Tanabe, Kazuko

    2008-06-15

    The approximate selection rules for the interband and intraband electromagnetic transitions are predicted referring to two quantum numbers, which are derived from an algebraic solution for the particle-rotor model with one high-j nucleon coupled to a triaxially deformed core. It is shown that the inclusion of angular momentum dependence for moments of inertia reproduces the experimental excitation energies relative to a reference quite well both for positive and negative parity TSD bands in {sup 161,163,165,167}Lu.

  6. Shape phase transition in odd-even nuclei: From spherical to deformed gamma-unstable shapes

    SciTech Connect

    Boeyuekata, M.; Alonso, C. E.; Arias, J. M.; Fortunato, L.; Vitturi, A.

    2010-07-15

    Shape phase transitions in odd-A nuclei are investigated within the framework of the interacting boson-fermion model. The case of a single j=9/2 fermion coupled to an even-even boson core is considered. This boson core transits from spherical to gamma-unstable shapes depending on the value of a control parameter in the boson Hamiltonian. The effect of the coupling of the odd particle to this core along the shape transition and, in particular, at the critical point is discussed. For that purpose, the ground-state energy surface in terms of the beta and gamma shape variables for the even core and odd-even energy surfaces for the different K states coming from j=9/2 are constructed. The evolution of each individual coupled state along the transition from the spherical [U(5)] to the gamma-unstable [O(6)] situation is investigated. One finds that the core-fermion coupling gives rise to a smoother transition than in the even-core case.

  7. Charge-exchange modes of excitation in deformed neutron-rich nuclei

    SciTech Connect

    Yoshida, Kenichi

    2015-10-15

    Gamow-Teller (GT) mode of excitation and β-decay properties of deformed neutron-rich even-N Zr isotopes are investigated in a self-consistent Skyrme energy-density-functional approach, in which the Hartree-Fock-Bogoliubov equation is solved in the coordinate space and the proton-neutron Quasiparticle-RPA equation is solved in the quasiparticle basis. It is found that a stronger collectivity is generated for the GT giant resonance as an increase in the neutron number. Furthermore, we find that the T = 0 pairing enhances the low-lying GT strengths cooperatively with the T = 1 pairing correlation depending on the microscopic structure of the low-lying mode and the shell structure around the Fermi levels, and that the enhanced strength shortens the β-decay half-lives by at most an order of magnitude.

  8. Deformation increase of high-spin core-excited isomers in the astatine nuclei

    SciTech Connect

    Scheveneels, G.; Hardeman, F.; Neyens, G.; Coussement, R. )

    1991-06-01

    Quadrupole moments of six high-spin isomers in the At isotopes have been measured with the level-mixing-spectroscopy method: {sup 208}At(16{sup {minus}}), {sup 209}At(29/2{sup +}), {sup 210}At(19{sup +},15{sup {minus}}), {sup 211}At(39/2{sup {minus}},29/2{sup +}). The results show that level mixing spectroscopy is a promising technique to determine quadrupole moments of isomers that are difficult to measure by other in-beam hyperfine interaction methods. A large increase of the quadrupole moment is observed if neutrons are excited across or removed from the {ital N}=126 shell closure. This behavior is explained in terms of an enhanced core softness for fewer core neutrons; the aligned valence particles, moving in equatorial orbits, then easily polarize the core towards oblate deformation.

  9. Structure of Nuclei Deformed at Maximum and the Mass Asymmetry in Low-Energy Fission

    SciTech Connect

    Carjan, N.; Rizea, M.; Pashkevich, V.

    2010-06-01

    Single-particle spectra of neutrons and protons in {sup 236}U at scission (i.e., the maximum deformation this nucleus can sustain) are calculated as function of the mass asymmetry of the future fission fragments. Modified Cassini ovals were used to describe the nuclear shapes involved. Moving away from symmetric fission up to very asymmetric fission we observe the appearance and the disappearance of closed shells. This explains the complexity of the mass distribution and the strong preference for asymmetric divisions. For a more quantitative analyses we have calculated the pairing gap DELTA and the Fermi energy gamma in the frame of the renormalized BCS theory. A strong dependence of DELTA on the fragment mass ratio A{sub H}/A{sub L} was found with a pronounced minimum at 1.5 for both neutrons and protons. This is in agreement with the most probable mass division measured in {sup 235}U(n{sub th},f). Concerning the Fermi energies, the protons have lower values than the neutrons by more than 1 MeV. They are also stronger bound at symmetry (A{sub L} = 110-118) than at large asymmetries (A{sub L} = 70-80). To answer the important question of where the mass asymmetry is determined we have extended the calculations to successive stages between saddle and scission.

  10. QPNM calculation for the ground state magnetic moments of odd-mass deformed nuclei: 157-167Er isotopes

    NASA Astrophysics Data System (ADS)

    Yakut, H.; Guliyev, E.; Guner, M.; Tabar, E.; Zenginerler, Z.

    2012-08-01

    A new microscopic method has been developed in the framework of the Quasiparticle-Phonon Nuclear Model (QPNM) in order to investigate spin polarization effects on the magnetic properties such as magnetic moment, intrinsic magnetic moment and effective gs factor of the ground state of odd-mass 157-167Er isotopes. The calculations were performed using both Tamm-Dancoff Approximation (TDA) and Quasiparticle Random-Phase Approximation (QRPA). Reasonably good agreement has been obtained between the QRPA results and the relevant experimental data. Furthermore the variation of the intrinsic magnetic moment gK values with the mass number A exhibits similar behavior for both theoretical and experimental results. From the compression of the calculated intrinsic magnetic moment values with the experimental data the spin-spin interaction parameter has been found as χ=(30/A) MeV for odd-mass 157-167Er isotopes. Our results clarify the possibility of using this new method to describe the magnetic properties of odd-mass deformed nuclei.

  11. Deformation and shape coexistence in 66,70Ni and 69,71Cu nuclei near N = 40

    NASA Astrophysics Data System (ADS)

    Walters, W. B.; Harker, J.; Chiara, C. J.; Janssens, R. V. F.; Albers, M.; Alcorta, M.; Bertone, P. F.; Carpenter, M. P.; Hoffman, C. R.; Kondev, F. G.; Lauritsen, T.; Rogers, A. M.; Seweryniak, D.; Zhu, S.; Broda, R.; Fornal, B.; Krolas, W.; Wrzesinski, J.; Larson, N.; Liddick, S. N.; Prokop, C.; Suchyta, S.; David, H. M.; Doherty, D. T.

    2013-10-01

    New data will be presented for the levels of 66,70Ni and 69,71Cu that extend some of the previously indicated features of deformation and shape coexistence in this region. [R. Broda et al., Phys. Rev. C 86, 064312 (2012)] Excited states in these nuclei were populated through multinucleon-transfer reactions using 70Zn beams provided by the ATLAS facility at ANL. In particular, possible structure associated with the 03+level in 66Ni will be discussed. New levels will be presented in 69,71Cu that extend the 2-particle-1-hole structures to higher energy and spin. [C. J. Chiara et al., Phys. Rev. C 85, 024309 (2012)] Data will be presented that support the placement of a new level in 70Ni at 2912 keV with a spin and parity of (5-). This work was supported by the US DoE under DE-FG02-94-ER40834 & DE-AC02-06CH11357, NNSA DE-NA0000979, and NSF under PHY- 1102511.

  12. Second order phase transitions from octupole-nondeformed to octupole-deformed shape in the alternating parity bands of nuclei around 240Pu based on data

    NASA Astrophysics Data System (ADS)

    Jolos, R. V.; von Brentano, P.; Jolie, J.

    2012-08-01

    Background: Shape phase transitions in finite quantal systems are very interesting phenomena of general physical interest. There is a very restricted number of the examples of nuclei demonstrating this phenomenon.Purpose: Based on experimental excitation spectra, there is a second order phase transition in the alternating parity bands of some actinide nuclei.Method: The mathematical techniques of supersymmetric quantum mechanics, two-center octupole wave functions ansatz, and the Landau theory of phase transitions are used to analyze the experimental data on alternating parity bands.Results: The potential energy of the octupole collective motion is determined and analyzed for all observed values of the angular momentum of the alternating parity band states in 232Th, 238U, and 240Pu.Conclusion: It is shown that as a function of increasing angular momentum there is a second order phase transition from the octupole-nondeformed to the octupole-deformed shape in the considered nuclei.

  13. Effective theory for the nonrigid rotor in an electromagnetic field: Toward accurate and precise calculations of E2 transitions in deformed nuclei

    DOE PAGES

    Coello Pérez, Eduardo A.; Papenbrock, Thomas F.

    2015-07-27

    In this paper, we present a model-independent approach to electric quadrupole transitions of deformed nuclei. Based on an effective theory for axially symmetric systems, the leading interactions with electromagnetic fields enter as minimal couplings to gauge potentials, while subleading corrections employ gauge-invariant nonminimal couplings. This approach yields transition operators that are consistent with the Hamiltonian, and the power counting of the effective theory provides us with theoretical uncertainty estimates. We successfully test the effective theory in homonuclear molecules that exhibit a large separation of scales. For ground-state band transitions of rotational nuclei, the effective theory describes data well within theoreticalmore » uncertainties at leading order. To probe the theory at subleading order, data with higher precision would be valuable. For transitional nuclei, next-to-leading-order calculations and the high-precision data are consistent within the theoretical uncertainty estimates. In addition, we study the faint interband transitions within the effective theory and focus on the E2 transitions from the 02+ band (the “β band”) to the ground-state band. Here the predictions from the effective theory are consistent with data for several nuclei, thereby proposing a solution to a long-standing challenge.« less

  14. Effective theory for the nonrigid rotor in an electromagnetic field: Toward accurate and precise calculations of E2 transitions in deformed nuclei

    SciTech Connect

    Coello Pérez, Eduardo A.; Papenbrock, Thomas F.

    2015-07-27

    In this paper, we present a model-independent approach to electric quadrupole transitions of deformed nuclei. Based on an effective theory for axially symmetric systems, the leading interactions with electromagnetic fields enter as minimal couplings to gauge potentials, while subleading corrections employ gauge-invariant nonminimal couplings. This approach yields transition operators that are consistent with the Hamiltonian, and the power counting of the effective theory provides us with theoretical uncertainty estimates. We successfully test the effective theory in homonuclear molecules that exhibit a large separation of scales. For ground-state band transitions of rotational nuclei, the effective theory describes data well within theoretical uncertainties at leading order. To probe the theory at subleading order, data with higher precision would be valuable. For transitional nuclei, next-to-leading-order calculations and the high-precision data are consistent within the theoretical uncertainty estimates. In addition, we study the faint interband transitions within the effective theory and focus on the E2 transitions from the 02+ band (the “β band”) to the ground-state band. Here the predictions from the effective theory are consistent with data for several nuclei, thereby proposing a solution to a long-standing challenge.

  15. Topographically induced self-deformation of the nuclei of cells: dependence on cell type and proposed mechanisms.

    PubMed

    Davidson, Patricia M; Fromigué, Olivia; Marie, Pierre J; Hasirci, Vasif; Reiter, Günter; Anselme, Karine

    2010-03-01

    Osteosarcoma-derived cell lines (SaOs-2, MG63) have recently been shown to deform their nucleus considerably in response to surface topography. Such a deformation had not been described previously. Here we present results on additional cell lines, including cancerous (OHS4, U2OS), immortalized (F/STRO-1(+)A and FHSO6) and healthy cells (HOP). The cancerous cells were found to deform extensively, the immortalized cells showed small deformations, whereas the healthy cells showed deformation only at short incubation times. These results suggest a strong link between the malignant transformation of cells and the state of the cytoskeletal network. We propose mechanisms to explain the deformation in which the cytoskeleton either pushes down on the nucleus during spreading or pulls it down upon adhesion to the pillars.

  16. Remnants of spherical shell structures in deformed nuclei: The impact of an N=64 neutron subshell closure on the structure of N~90 gadolinium nuclei

    SciTech Connect

    Ross, T.J.; Hughes, R.O.; Beausang, C.W.; Allmond, James M; Angell, C.T.; Basunia, M.S.; Bleuel, D.L.; Burke, J.T.; Casperson, R.J.; Escher, J.E.; Fallon, P.; Hatarik, R.; Munson, J.; Paschalis, S.; Petri, M.; Phair, L.; Ressler, J.J.; Scielzo, N.D.

    2013-01-01

    Odd-mass gadolinium isotopes around N = 90 were populated by the (p,d ) reaction, utilizing 25-MeV protons, resulting in population of low-spin quasineutron states at energies near and below the Fermi surface. Systematics of the single quasineutron levels populated are presented. A large excitation energy gap is observed between levels originating from the 2d3/2 , 1h11/2 , and 3s1/2 spherical parents (above the N = 64 gap), and the 2d5/2 (below the gap), indicating that the spherical shell model level spacing is maintained at least to moderate deformations.

  17. Remnants of spherical shell structures in deformed nuclei: The impact of an N=64 neutron subshell closure on the structure of N≈90 gadolinium nuclei

    NASA Astrophysics Data System (ADS)

    Ross, T. J.; Hughes, R. O.; Beausang, C. W.; Allmond, J. M.; Angell, C. T.; Basunia, M. S.; Bleuel, D. L.; Burke, J. T.; Casperson, R. J.; Escher, J. E.; Fallon, P.; Hatarik, R.; Munson, J.; Paschalis, S.; Petri, M.; Phair, L. W.; Ressler, J. J.; Scielzo, N. D.

    2013-09-01

    Odd-mass gadolinium isotopes around N=90 were populated by the (p,d) reaction, utilizing 25-MeV protons, resulting in population of low-spin quasineutron states at energies near and below the Fermi surface. Systematics of the single quasineutron levels populated are presented. A large excitation energy gap is observed between levels originating from the 2d3/2, 1h11/2, and 3s1/2 spherical parents (above the N=64 gap), and the 2d5/2 (below the gap), indicating that the spherical shell model level spacing is maintained at least to moderate deformations.

  18. Anomalous Neutron Capture and Plastic Deformation of cu and pd Cathodes during Electrolysis in a Weak Thermalized Neutron Field:. Evidence of Nuclei-Lattice Exchange

    NASA Astrophysics Data System (ADS)

    Lipson, A. G.; Miley, G. H.; Lipson, A. G.

    2006-02-01

    Anomalous neutron capture and plastic deformation in the hardened Cu and Pd cathodes has been established under combined action of electrolysis and a weak thermalized neutron field (WTNF) with a flux in the range of 180-400 n/s cm2. Experiments with these cathodes showed ~7.0% decrease in the 2224 keV n-D gamma peak accompanying thermalized neutron capture inside the PE cavity during electrolysis vs. experiments with annealed Cu and Pd as well as with the background runs (i.e., no electrolysis). The anomalous neutron capture and plastic deformation of Cu and Pd cathodes under combined action of electrolysis and WTNF may be explained energetically by assuming a selective radiationless thermalized neutron capture at high-internal strain concentration sites in the hardened cathodes. The results of these experiments provide straightforward (avoids the Coulomb barrier penetration issue) evidence that nuclei-lattice energy exchange can result in an increase in neutron capture probability and radiationless de-excitation of the resulting compound nuclei.

  19. From superdeformation to extreme deformation and clusterization in the N ≈Z nuclei of the A ≈40 mass region

    NASA Astrophysics Data System (ADS)

    Ray, D.; Afanasjev, A. V.

    2016-07-01

    A systematic search for extremely deformed structures in the N ≈Z nuclei of the A ≈40 mass region has been performed for the first time in the framework of covariant density functional theory. At spin zero such structures are located at high excitation energies, which prevents their experimental observation. The rotation acts as a tool to bring these exotic shapes to the yrast line or its vicinity so that their observation could become possible with future generation of γ -tracking (or similar) detectors such as GRETA and AGATA. The major physical observables of such structures (such as transition quadrupole moments, as well as kinematic and dynamic moments of inertia), the underlying single-particle structure and the spins at which they become yrast or near yrast, are defined. The search for the fingerprints of clusterization and molecular structures is performed and the configurations with such features are discussed. The best candidates for observation of extremely deformed structures are identified. For several nuclei in this study (such as 36Ar), the addition of several spin units above the currently measured maximum spin of 16 ℏ will inevitably trigger the transition to hyper- and megadeformed nuclear shapes.

  20. Superdeformed nuclei

    SciTech Connect

    Janssens, R.V.F.; Khoo, Teng Lek.

    1991-01-01

    This paper reviews the most recent advances in the understanding of the physics of superdeformed nuclei from the point of view of the experimentalists. It covers among other subjects the following topics: (1) the discovery of a new region of superdeformed nuclei near A=190, (2) the surprising result of the occurrence of bands with identical transition energies in neighboring superdeformed nuclei near A=150 and A=190, (3) the importance of octupole degrees of freedom at large deformation and (4) the properties associated with the feeding and the decay of superdeformed bands. The text presented hereafter will appear as a contribution to the Annual Review of Nuclear and Particle Science, Volume 41. 88 refs., 11 figs.

  1. Microscopic time-dependent analysis of neutrons transfers at low-energy nuclear reactions with spherical and deformed nuclei

    NASA Astrophysics Data System (ADS)

    Samarin, Viacheslav

    2014-03-01

    Time-dependent Schrödinger equation is numerically solved by difference method for external neutrons of nuclei 6He, 18O, 48Са, 238U at their grazing collisions with energies in the vicinity of a Coulomb barrier. The spin-orbital interaction and Pauli's exclusion principle were taken into consideration during the solution.

  2. Color coherent effects in (e,e{prime}N) and (e,e{prime}N,N(h)) processes at CEBAF

    SciTech Connect

    Frankfurt, L.L.; Sargsyan, M.M.; Strikman, M.I. |

    1994-04-01

    The options for investigating color coherent effects and competing nuclear effects of nucleon-nucleon correlations in nuclei, nuclear shell effects in (e, e{prime}N) and (e, e{prime}NN(h)) reactions are considered. They argue that extension of CEBAF energies to reach Q{sup 2} = 10 GeV{sup 2} will allow systematical investigations of color coherent effects in nonperturbative regime of QCD and their interplay with nuclear effects.

  3. Effect of the Pauli principle on the deformed quasiparticle random-phase approximation calculations and its consequence for β -decay calculations of deformed even-even nuclei

    NASA Astrophysics Data System (ADS)

    Fang, Dong-Liang

    2016-03-01

    In this work, I take into consideration the Pauli exclusion principle (PEP) in the quasiparticle random-phase approximation (QRPA) calculations for the deformed systems by replacing the traditional quasiboson approximation (QBA) with the renormalized one. With this new formalism, the parametrization of QRPA calculations has been changed and the collapse of QRPA solutions could be avoid for realistic gp p values. I further find that the necessity of the renormalization parameter of particle-particle residual interaction gp p in QRPA calculations is due to the exclusion of PEP. So with the inclusion of PEP, I could easily extend the deformed QRPA calculations to the less-explored region where lack of experimental data prevent effective parametrization of gp p for QRPA methods. With this theoretical improvement, I give predictions of weak decay rates for even-even isotopes in the rare-earth region and compare the results with existing calculations.

  4. Direct Evidence for Octupole Deformation in Ba 146 and the Origin of Large E 1 Moment Variations in Reflection-Asymmetric Nuclei

    NASA Astrophysics Data System (ADS)

    Bucher, B.; Zhu, S.; Wu, C. Y.; Janssens, R. V. F.; Bernard, R. N.; Robledo, L. M.; Rodríguez, T. R.; Cline, D.; Hayes, A. B.; Ayangeakaa, A. D.; Buckner, M. Q.; Campbell, C. M.; Carpenter, M. P.; Clark, J. A.; Crawford, H. L.; David, H. M.; Dickerson, C.; Harker, J.; Hoffman, C. R.; Kay, B. P.; Kondev, F. G.; Lauritsen, T.; Macchiavelli, A. O.; Pardo, R. C.; Savard, G.; Seweryniak, D.; Vondrasek, R.

    2017-04-01

    Despite the more than 1 order of magnitude difference between the measured dipole moments in Ba 144 and Ba 146 , the octupole correlations in Ba 146 are found to be as strong as those in Ba 144 with a similarly large value of B (E 3 ;3-→0+) determined as 48 ( +21 -29 ) W .u . The new results not only establish unambiguously the presence of a region of octupole deformation centered on these neutron-rich Ba isotopes, but also manifest the dependence of the electric dipole moments on the occupancy of different neutron orbitals in nuclei with enhanced octupole strength, as revealed by fully microscopic calculations.

  5. Direct Evidence for Octupole Deformation in ^{146}Ba and the Origin of Large E1 Moment Variations in Reflection-Asymmetric Nuclei.

    PubMed

    Bucher, B; Zhu, S; Wu, C Y; Janssens, R V F; Bernard, R N; Robledo, L M; Rodríguez, T R; Cline, D; Hayes, A B; Ayangeakaa, A D; Buckner, M Q; Campbell, C M; Carpenter, M P; Clark, J A; Crawford, H L; David, H M; Dickerson, C; Harker, J; Hoffman, C R; Kay, B P; Kondev, F G; Lauritsen, T; Macchiavelli, A O; Pardo, R C; Savard, G; Seweryniak, D; Vondrasek, R

    2017-04-14

    Despite the more than 1 order of magnitude difference between the measured dipole moments in ^{144}Ba and ^{146}Ba, the octupole correlations in ^{146}Ba are found to be as strong as those in ^{144}Ba with a similarly large value of B(E3;3^{-}→0^{+}) determined as 48(+21-29)  W.u. The new results not only establish unambiguously the presence of a region of octupole deformation centered on these neutron-rich Ba isotopes, but also manifest the dependence of the electric dipole moments on the occupancy of different neutron orbitals in nuclei with enhanced octupole strength, as revealed by fully microscopic calculations.

  6. Direct evidence for octupole deformation in Ba146 and the origin of large E1 moment variations in reflection-asymmetric nuclei

    DOE PAGES

    Bucher, B.; Zhu, S.; Wu, C. Y.; ...

    2017-04-12

    Despite the more than 1 order of magnitude difference between the measured dipole moments in 144Ba and 146Ba, the octupole correlations in 146Ba are found to be as strong as those in 144Ba with a similarly large value of B(E3;3– → 0+) determined as 48(+21–29) W.u. Here, the new results not only establish unambiguously the presence of a region of octupole deformation centered on these neutron-rich Ba isotopes, but also manifest the dependence of the electric dipole moments on the occupancy of different neutron orbitals in nuclei with enhanced octupole strength, as revealed by fully microscopic calculations.

  7. Estimation of M 1 scissors mode strength for deformed nuclei in the medium- to heavy-mass region by statistical Hauser-Feshbach model calculations

    NASA Astrophysics Data System (ADS)

    Mumpower, M. R.; Kawano, T.; Ullmann, J. L.; Krtička, M.; Sprouse, T. M.

    2017-08-01

    Radiative neutron capture is an important nuclear reaction whose accurate description is needed for many applications ranging from nuclear technology to nuclear astrophysics. The description of such a process relies on the Hauser-Feshbach theory which requires the nuclear optical potential, level density, and γ -strength function as model inputs. It has recently been suggested that the M 1 scissors mode may explain discrepancies between theoretical calculations and evaluated data. We explore statistical model calculations with the strength of the M 1 scissors mode estimated to be dependent on the nuclear deformation of the compound system. We show that the form of the M 1 scissors mode improves the theoretical description of evaluated data and the match to experiment in both the fission product and actinide regions. Since the scissors mode occurs in the range of a few keV to a few MeV, it may also impact the neutron capture cross sections of neutron-rich nuclei that participate in the rapid neutron capture process of nucleosynthesis. We comment on the possible impact to nucleosynthesis by evaluating neutron capture rates for neutron-rich nuclei with the M 1 scissors mode active.

  8. The NLC IR and e+e-/e- e- Compatibility Issues

    SciTech Connect

    Markiewicz, Thomas W

    2003-01-29

    This paper collects and summarizes information presented at previous e- e- workshops. Firstly, the various options for reconfiguring magnets and power sources to convert the NLC to e- e- operation are discussed. Secondly, the expected backgrounds from pair creation at the interaction point are presented. Lastly, beam loss in the extraction line is discussed.

  9. Description of superdeformed nuclei in the A{approx}190 region by generalized deformed su{sub q}(2)

    SciTech Connect

    Alharbi, H. H.; Alhendi, H. A.; Alhakami, F. S.

    2009-05-15

    The generalized deformed su{sub q}(2) model is applied to 79 superdeformed bands in the region A{approx}190. The transition energies and the moments of inertia are calculated within the model and their validity is investigated by comparing them with the experimental data. Both the standard su{sub q}(2) and the generalized one fail to account for the uprising and the downturn of the dynamic moments of inertia. Both models, however, show remarkable agreement with the available experimental data at low angular frequency (({Dirac_h}/2{pi}){omega}{<=}0.25 MeV)

  10. Neutrinoless double-{beta} decay of deformed nuclei within quasiparticle random-phase approximation with a realistic interaction

    SciTech Connect

    Fang Dongliang; Faessler, Amand; Rodin, Vadim; Simkovic, Fedor

    2011-03-15

    In this paper a microscopic approach to calculation of the nuclear matrix element M{sup 0{nu}} for neutrinoless double-{beta} decay with an account for nuclear deformation is presented in length and applied for {sup 76}Ge, {sup 150}Nd, and {sup 160}Gd. The proton-neutron quasiparticle random-phase approximation with a realistic residual interaction (the Brueckner G matrix derived from the charge-depending Bonn nucleon-nucleon potential) is used as the underlying nuclear structure model. The effects of the short-range correlations and the quenching of the axial vector coupling constant g{sub A} are analyzed. The results suggest that neutrinoless double-{beta} decay of {sup 150}Nd, to be measured soon by the SNO+ Collaboration, may provide one of the best probes of the Majorana neutrino mass. This confirms our preliminary conclusion in Fang et al. [Phys. Rev. C 82, 051301(R) (2010)].

  11. Deformed shell model calculations of half lives for β+/EC decay and 2ν β+β+/β+EC/ECEC decay in medium-heavy N~Z nuclei

    NASA Astrophysics Data System (ADS)

    Mishra, S.; Shukla, A.; Sahu, R.; Kota, V. K. B.

    2008-08-01

    The β+/EC half-lives of medium heavy N~Z nuclei with mass number A~64-80 are calculated within the deformed shell model (DSM) based on Hartree-Fock states by employing a modified Kuo interaction in (2p3/2,1f5/2,2p1/2,1g9/2) space. The DSM model has been quite successful in predicting many spectroscopic properties of N~Z medium heavy nuclei with A~64-80. The calculated β+/EC half-lives, for prolate and oblate shapes, compare well with the predictions of the calculations with Skyrme force by Sarriguren Going further, following recent searches, half-lives for 2ν β+β+/β+EC/ECEC decay for the nucleus Kr78 are calculated using DSM and the results compare well with QRPA predictions.

  12. Job Prospects for E/E Engineers.

    ERIC Educational Resources Information Center

    Basta, Nicholas

    1987-01-01

    Discusses the trends in employment in the electrical/electronics (E/E) engineering industry. States that although the number of E/E graduates grew at a rate of over 11 percent from 1985 to 1986, the economy continues to be the major determinant in the job outlook in the field. (TW)

  13. Job Prospects for E/E Engineers.

    ERIC Educational Resources Information Center

    Basta, Nicholas

    1986-01-01

    Reviews job prospects for electrical/electronic E/E engineers, indicating that 1985 was not a banner year due to problems in the semiconductor manufacturing industries and in telecommunications. Also indicates that an upturn is expected for 1986 E/E graduates. (JN)

  14. Job Prospects for E/E Engineers.

    ERIC Educational Resources Information Center

    Basta, Nicholas

    1986-01-01

    Reviews job prospects for electrical/electronic E/E engineers, indicating that 1985 was not a banner year due to problems in the semiconductor manufacturing industries and in telecommunications. Also indicates that an upturn is expected for 1986 E/E graduates. (JN)

  15. Job Prospects for E/E Engineers.

    ERIC Educational Resources Information Center

    Basta, Nicholas

    1987-01-01

    Discusses the trends in employment in the electrical/electronics (E/E) engineering industry. States that although the number of E/E graduates grew at a rate of over 11 percent from 1985 to 1986, the economy continues to be the major determinant in the job outlook in the field. (TW)

  16. Description of nuclear octupole and quadrupole deformation close to axial symmetry: Octupole vibrations in the X(5) nuclei Nd150 and Sm152

    NASA Astrophysics Data System (ADS)

    Bizzeti, P. G.; Bizzeti-Sona, A. M.

    2010-03-01

    The model, introduced in a previous paper, for the description of the octupole and quadrupole degrees of freedom in conditions close to the axial symmetry is used to describe the negative-parity band based on the first octupole vibrational state in nuclei close to the critical point of the U(5)-to-SU(3) phase transition. The situation of Nd150 and Sm152 is discussed in detail. The positive-parity levels of these nuclei, and also the in-band E2 transitions, are reasonably accounted for by the X(5) model. With simple assumptions on the nature of the octupole vibrations, it is also possible to describe the negative-parity sector with comparable accuracy without changing the description of the positive-parity part.

  17. High spin spectroscopy in 219Ra: Search for the lower mass boundary of the region of statically octupole-deformed nuclei

    NASA Astrophysics Data System (ADS)

    Hensley, T. C.; Cottle, P. D.; Tripathi, Vandana; Abromeit, B.; Anastasiou, M.; Baby, L. T.; Baron, J. S.; Caussyn, D.; Dungan, R.; Kemper, K. W.; Lubna, R. S.; Miller, S. L.; Rijal, N.; Riley, M. A.; Tabor, S. L.; Tai, P.-L.; Villafana, K.

    2017-09-01

    We report the results of a study of rotational bands in 219Ra via the 208Pb(14C,3 n ) reaction to look for evidence that this nucleus is statically octupole deformed. We add 19 γ rays not previously observed to the level scheme and extend the two most strongly populated alternating parity bands to J =51 /2 and 45/2. The magnitude of the energy splitting between the spin-parity doublets in the two bands appears to exclude the possibility that 219Ra has a static octupole deformation.

  18. Electroproduction of Strange Nuclei

    SciTech Connect

    E.V. Hungerford

    2002-06-01

    The advent of high-energy, CW-beams of electrons now allows electro-production and precision studies of nuclei containing hyperons. Previously, the injection of strangeness into a nucleus was accomplished using secondary beams of mesons, where beam quality and target thickness limited the missing mass resolution. We review here the theoretical description of the (e, e'K+) reaction mechanism, and discuss the first experiment demonstrating that this reaction can be used to precisely study the spectra of light hypernuclei. Future experiments based on similar techniques, are expected to attain even better resolutions and rates.

  19. Identification of highly deformed even-even nuclei in the neutron- and proton-rich regions of the nuclear chart from the B(E2)↑ and E2 predictions in the generalized differential equation model

    NASA Astrophysics Data System (ADS)

    Nayak, R. C.; Pattnaik, S.

    2015-11-01

    We identify here the possible occurrence of large deformations in the neutron- and proton-rich (n-rich and p-rich) regions of the nuclear chart from extensive predictions of the values of the reduced quadrupole transition probability B(E2)↑ for the transition from the ground state to the first 2+ state and the corresponding excitation energy E2 of even-even nuclei in the recently developed generalized differential equation (GDE) model exclusively meant for these physical quantities. This is made possible from our analysis of the predicted values of these two physical quantities and the corresponding deformation parameters derived from them such as the quadrupole deformation β2, the ratio of β2 to the Weisskopf single-particle β2(sp) and the intrinsic electric quadrupole moment Q0, calculated for a large number of both known as well as hitherto unknown even-even isotopes of oxygen to fermium (0 to FM; Z = 8-100). Our critical analysis of the resulting data convincingly support possible existence of large collectivity for the nuclides 30,32Ne,34Mg, 60Ti, 42,62,64Cr,50,68Fe, 52,72Ni, 72,70,96Kr,74,76Sr,78,80,106,108Zr, 82,84,110,112Mo, 140Te,144Xe, 148Ba,122Ce, 128,156Nd,130,132,158,160Sm and 138,162,164,166Gd, whose values of β2 are found to exceed 0.3 and even 0.4 in some cases. Our findings of large deformations in the exotic n-rich regions support the existence of another “island of inversion” in the heavy-mass region possibly caused by breaking of the N = 70 subshell closure.

  20. Short-Distance Structure of Nuclei

    SciTech Connect

    Douglas Higinbotham, Eliazer Piasetzky, Stephen Wood

    2011-06-01

    One of Jefferson Lab's original missions was to further our understanding of the short-distance structure of nuclei. In particular, to understand what happens when two or more nucleons within a nucleus have strongly overlapping wave-functions; a phenomena commonly referred to as short-range correlations. Herein, we review the results of the (e,e'), (e,e'p) and (e,e'pN) reactions that have been used at Jefferson Lab to probe this short-distance structure as well as provide an outlook for future experiments.

  1. Deformation of the very neutron-deficient rare-earth nuclei produced with the SPIRAL 76Kr radioactive beam and studied with EXOGAM + DIAMANT

    SciTech Connect

    Redon, N.; Guinet, D.; Lautesse, Ph.; Meyer, M.; Rosse, B.; Stezowski, O.; France, G. de; Casandjian, J. M.

    2004-02-27

    The structure of the very neutron-deficient rare-earth nuclei has been investigated in the first experiment with the EXOGAM gamma array coupled to the DIAMANT light charged particle detector using radioactive beam of 76Kr delivered by the SPIRAL facility. Very neutron-deficient Pr, Nd and Pm isotopes have been populated at rather high spin by the reaction 76Kr + 58Ni at a beam energy of 328 MeV. We report here the first results of this experiment.

  2. Study of the {Delta} structure and N{Delta} interactions with N(e,e'{pi}) and d(e,e'{pi}) reactions.

    SciTech Connect

    Lee, T.-S. H.

    1998-09-11

    A dynamical approach for using the {gamma}N {r_arrow} {pi}N and N(e,e{prime}{pi}) reactions to test the chiral constituent quark model is reviewed. Recent results for the {Delta} excitations and predictions for future experiments are presented. It is shown that the polarization observables of d(e,e{prime}{pi}) reactions are useful for investigating the N{Delta} interactions which are crucial in exploring the {Delta} components in nuclei and the properties of {Delta}-rich systems created in relativistic heavy-ion collisions.

  3. Octupole shapes in heavy nuclei

    SciTech Connect

    Ahmad, I.

    1994-08-01

    Theoretical calculations and measurements show the presence of strong octupole correlations in thecyround states and low-lying states of odd-mass and odd-odd nuclei in the RaPa region. Evidence for octupole correlations is provided by the observation of parity doublets and reductions in M1 matrix elements, decoupling parameters, and Coriolis matrix elements Involving high-j states. Enhancement of E1 transition rates has also been observed for some of the octupole deformed nuclei. The most convincing argument for octupole deformation is provided by the similarities of the reduced alpha decay rates to the two members of parity doublets.

  4. Collective Motions in A = 100-112 Nuclei

    SciTech Connect

    Hamilton, J. H.; Ramayya, A. V.; Hwang, J. K.; Goodin, C.; Zhu, S. J.; Luo, Y. X.; Rasmussen, J. O.; Frauendorf, S.; Ter-Akopian, G. M.

    2010-10-11

    With a very high statistics data set with 5.7x10{sup 11} triple and higher fold {gamma} coincidences from the spontaneous fission of {sup 252}Cf, a wealth of fascinating new collective motions in nuclei with A = 100-112 have been observed. Nothing was known previously about one- and two-phonon {gamma}-bands in odd-A nuclei. We discovered the first one-and two- phonon {gamma} vibrational bands in an odd N-even Z nucleus, {sup 105}Mo. The energies of the one- and two- phonon bands in {sup 104}Mo, {sup 105}Mo, {sup 106}Mo and {sup 108}Mo were recently studied and are remarkably similar in energies. The first chiral doublet bands in e-e nuclei were observed in triaxial {sup 106,108}Mo and {sup 110,112}Ru while such chiral band in {sup 108}Ru are perturbed by its {gamma}-soft shape. The experimental evidences, including our recent angular correlation studies are presented along with what these new bands are telling us about the evolving collective structures and deformation in this region.

  5. Physics of Unstable Nuclei

    NASA Astrophysics Data System (ADS)

    Khoa, Dao Tien; Egelhof, Peter; Gales, Sydney; Giai, Nguyen Van; Motobayashi, Tohru

    2008-04-01

    ]C([symbol], n)[symbol]O by the transfer reaction [symbol]C([symbol]Li, t)[symbol]O / F. Hammache et al. -- SPIRAL2 at GANIL: a world of leading ISOL facility for the physics of exotic nuclei / S. Gales -- Magnetic properties of light neutron-rich nuclei and shell evolution / T. Suzuki, T. Otsuka -- Multiple scattering effects in elastic and quasi free proton scattering from halo nuclei / R. Crespo et al. -- The dipole response of neutron halos and skins / T. Aumann -- Giant and pygmy resonances within axially-symmetric-deformed QRPA with the Gogny force / S. Péru, H. Goutte -- Soft K[symbol] = O+ modes unique to deformed neutron-rich unstable nuclei / K. Yoshida et al. -- Synthesis, decay properties, and identification of superheavy nuclei produced in [symbol]Ca-induced reactions / Yu. Ts. Oganessian et al. -- Highlights of the Brazilian RIB facility and its first results and hindrance of fusion cross section induced by [symbol]He / P. R. S. Gomes et al. -- Search for long fission times of super-heavy elements with Z = 114 / M. Morjean et al. -- Microscopic dynamics of shape coexistence phenomena around [symbol]Se and [symbol]Kr / N. Hinohara et al. -- [symbol]-cluster states and 4[symbol]-particle condensation in [symbol]O / Y. Funaki et al. -- Evolution of the N = 28 shell closure far from stability / O. Sorlin et al. -- Continuum QRPA approach and the surface di-neutron modes in nuclei near the neutron drip-line / M. Matsuo et al. -- Deformed relativistic Hartree-Bogoliubov model for exotic nuclei / S. G. Zhou et al. -- Two- and three-body correlations in three-body resonances and continuum states / K. Katō, K. Ikeda -- Pion- and Rho-Meson effects in relativistic Hartree-Fock and RPA / N. V. Giai et al. -- Study of the structure of neutron rich nuclei by using [symbol]-delayed neutron and gamma emission method / Y. Ye et al. -- Production of secondary radioactive [symbol] Na beam for the study of [symbol]Na([symbol], p)[symbol]Mg stellar reaction / D. N. Binh et al

  6. Exotic atomic nuclei

    NASA Astrophysics Data System (ADS)

    Hamilton, J. H.; Maruhn, J. A.

    1986-07-01

    From the study of nuclei with abundances of neutrons and protons (N numbers and Z numbers) quite different from those found in nature, it has been possible to gain new views of motions and structures within nuclear matter. Based on the spherical shell model of the nucleus proposed by Mayer and Jensen in 1949 and the collective model of nuclear deformation proposed in 1952 by Bohr and Mottelson, it has come to be possible to decide what shape or shapes a nucleus must have for a given set of N and Z numbers. It turns out that not only spherical nuclei are possible but also prolate and oblate spheroids (football and discus shaped), triaxial (like a partially deflated football), and even pear- or peanut-shaped. A significant experimental tool in such studies is the ISOL or Isotope-Separator, On-Line, which makes possible the construction of energy level diagrams from the study of exotic nuclei created when particles from accelerators strike various kinds of foil. The significance of magic numbers and super-magic numbers (particular combinations of N and Z) for the stability of various exotic nuclei is considered. International facilities engaged in such studies are noted.

  7. Exotic phenomena in nuclei

    NASA Astrophysics Data System (ADS)

    Neff, Thomas; Feldmeier, Hans; Roth, Robert

    2006-10-01

    In the Fermionic Molecular Dynamics (FMD) model the nuclear many-body system is described using Slater determinants with Gaussian wave-packets as single-particle states. The flexibility of the FMD wave functions allows for a consistent description of shell model like structures, deformed states, cluster structures as well as halos. An effective interaction derived from the realistic Argonne V18 interaction using the Unitary Correlation Operator Method is used for all nuclei. Results for nuclei in the p-shell will be presented. Halo features are present in the Helium isotopes, cluster structures are studied in Beryllium and Carbon isotopes. The interplay between shell structure and cluster structures in the ground and the Hoyle state in ^12C will be discussed.

  8. D(e,e'p) data

    SciTech Connect

    Werner U. Boeglin

    2005-02-01

    One hopes to learn about the short range structure of the deuteron by measuring the D(e,e'p)n cross section at large nucleon momenta. The problems of previous experiments are discussed and a recent Hall A experiment at Jefferson Lab is presented.

  9. Predictions for Superheavy Nuclei

    NASA Astrophysics Data System (ADS)

    Kumar, Krishna

    1990-01-01

    The Dynamic Deformation Model has been extended to the problem of fission in such a way that several thousand channels including particle-decay, α-decay, heavy-ion-emission, asymmetric fission, and symmetric fission can be taken into account. The model also includes a Kinetic Shell Correction which was ignored in previous predictions for Superheavy nuclei. This model is in better agreement with experimental life-times. A new location of the Superheavy peak is predicted at Z = 116 (eka-Polonium), A = 300, total half-life = 1079 years. New heavy-ion-fusion experiments and the means of identifying the Superheavy Elements are suggested.

  10. Cosmogenic nuclei

    NASA Technical Reports Server (NTRS)

    Raisbeck, G. M.

    1986-01-01

    Cosmogenic nuclei, nuclides formed by nuclear interactions of galactic and solar cosmic rays with extraterrestrial or terrestrial matter are discussed. Long lived radioactive cosmogenic isotopes are focused upon. Their uses in dating, as tracers of the interactions of cosmic rays with matter, and in obtaining information on the variation of primary cosmic ray flux in the past are discussed.

  11. Review of metastable states in heavy nuclei

    SciTech Connect

    Dracoulis, G. D.; Walker, P. M.; Kondev, F. G.

    2016-05-31

    Here, the structure of nuclear isomeric states is reviewed in the context of their role in contemporary nuclear physics research. Emphasis is given to high-spin isomers in heavy nuclei, with A ≳ 150. The possibility to exploit isomers to study some of the most exotic nuclei is a recurring theme. In spherical nuclei, the role of octupole collectivity is discussed in detail, while in deformed nuclei the limitations of the K quantum number are addressed. Isomer targets and isomer beams are considered, along with applications related to energy storage, astrophysics, medicine, and experimental advances.

  12. Review of metastable states in heavy nuclei

    DOE PAGES

    Dracoulis, G. D.; Walker, P. M.; Kondev, F. G.

    2016-05-31

    Here, the structure of nuclear isomeric states is reviewed in the context of their role in contemporary nuclear physics research. Emphasis is given to high-spin isomers in heavy nuclei, with A ≳ 150. The possibility to exploit isomers to study some of the most exotic nuclei is a recurring theme. In spherical nuclei, the role of octupole collectivity is discussed in detail, while in deformed nuclei the limitations of the K quantum number are addressed. Isomer targets and isomer beams are considered, along with applications related to energy storage, astrophysics, medicine, and experimental advances.

  13. Review of metastable states in heavy nuclei

    NASA Astrophysics Data System (ADS)

    Dracoulis, G. D.; Walker, P. M.; Kondev, F. G.

    2016-07-01

    The structure of nuclear isomeric states is reviewed in the context of their role in contemporary nuclear physics research. Emphasis is given to high-spin isomers in heavy nuclei, with A≳ 150 . The possibility to exploit isomers to study some of the most exotic nuclei is a recurring theme. In spherical nuclei, the role of octupole collectivity is discussed in detail, while in deformed nuclei the limitations of the K quantum number are addressed. Isomer targets and isomer beams are considered, along with applications related to energy storage, astrophysics, medicine, and experimental advances.

  14. Reflection asymmetric shapes in nuclei

    SciTech Connect

    Ahmad, I.; Carpenter, M.P.; Emling, H.; Holzmann, R.; Janssens, R.V.F.; Khoo, T.L.; Moore, E.F.; Morss, L.R.; Durell, J.L.; Fitzgerald, J.B.; Mowbary, A.S.; Hotchkiss, M.A.; Phillips, W.R.; Drigert, M.W.; Ye, D.; Benet, P.; Manchester Univ. . Dept. of Physics; EG and G Idaho, Inc., Idaho Falls, ID; Notre Dame Univ., IN; Purdue Univ., Lafayette, IN )

    1989-01-01

    Experimental data show that there is no even-even nucleus with a reflection asymmetric shape in its ground state. Maximum octupole- octupole correlations occur in nuclei in the mass 224 (N{approximately}134, Z{approximately}88) region. Parity doublets, which are the characteristic signature of octupole deformation, have been observed in several odd mass Ra, Ac and Pa nuclei. Intertwined negative and positive parity levels have been observed in several even-even Ra and Th nuclei above spin {approximately}8{Dirac h}. In both cases, the opposite parity states are connected by fast El transitions. In some medium-mass nuclei intertwined negative and positive parity levels have also been observed above spin {approximately}7{Dirac h}. The nuclei which exhibit octupole deformation in this mass region are {sup 144}Ba, {sup 146}Ba and {sub 146}Ce; {sup 142}Ba, {sup 148}Ce, {sup 150}Ce and {sup 142}Xe do not show these characteristics. No case of parity doublet has been observed in the mass 144 region. 32 refs., 16 figs., 1 tab.

  15. Separation of e+e- → e+e- and e+e- → π+π- events using SND detector calorimeter

    NASA Astrophysics Data System (ADS)

    Achasov, M. N.; Beloborodov, K. I.; Kupich, A. S.

    2017-01-01

    The technique of discrimination of the e+e- → e+e- and e+e- → π+π- events in energy range 0.5 < √s < 1 GeV by energy deposition in the calorimeter of SND detector was developed by applying machine learning method. Identification efficiency for e+e- → e+e- and e+e- → π+π- events in the range from 99.3 to 99.8% has been achived.

  16. Exotic Nuclei

    SciTech Connect

    Galindo-Uribarri, Alfredo {nmn}

    2010-01-01

    Current experimental developments on the study of exotic nuclei far from the valley of stability are discussed. I start with general aspects related to the production of radioactive beams followed by the description of some of the experimental tools and specialized techniques for studies in reaction spectroscopy, nuclear structure research and nuclear applications with examples from selected topical areas with which I have been involved. I discuss some of the common challenges faced in Accelerator Mass Spectrometry (AMS) and Radioactive Ion Beam (RIB) science.

  17. Proton emission from triaxial nuclei

    SciTech Connect

    Delion, D.S.; Wyss, R.; Karlgren, D.; Liotta, R.J.

    2004-12-01

    Proton decay from triaxially deformed nuclei is investigated. The deformation parameters corresponding to the mother nucleus are determined microscopically and the calculated decay widths are used to probe the mean-field wave function. The proton wave function in the mother nucleus is described as a resonant state in a coupled-channel formalism. The decay width, as well as the angular distribution of the decaying particle, are evaluated and their dependence upon the triaxial deformation parameters is studied in the decay of {sup 161}Re and {sup 185}Bi. It is found that the decay width is very sensitive to the parameters defining the triaxial deformation while the angular distribution is a universal function which does not depend upon details of the nuclear structure.

  18. Spatial dependence of pairing in deformed nuclei

    SciTech Connect

    Balbutsev, E. B.; Malov, L. A.; Schuck, P.

    2011-11-15

    The solution of time-dependent Hartree-Fock-Bogoliubov equations by the Wignerfunction-moments method leads to the appearance of refined low-lying modes whose description requires the accurate knowledge of the anomalous density matrix. It is shown that calculations with Woods-Saxon potential satisfy this requirement, producing an anomalous density matrix of the same quality as more complicated calculations with realistic forces.

  19. Onset of deformation in polonium nuclei

    SciTech Connect

    Younes, W.; Cizewski, J.A.

    1996-12-31

    The authors have been able to reproduce the systematics of the positive-parity states in {sup 192-208}Po within the framework of the Particle-Core Model. The wave-functions of the 2{sup +}{sub 1} states have been extracted using the Quasiparticle Random Phase Approximation. The increase in the collective motion of the lighter isotopes comes from the increased proton-neutron interaction when the neutrons and protons both occupy high-j orbitals.

  20. Fission barrier of actinides and superheavy nuclei: effect of pairing interaction

    NASA Astrophysics Data System (ADS)

    Abusara, H.

    2017-06-01

    Systematic calculations of fission barriers for axial deformation are performed for even-even nuclei in actinides region of the nuclear chart and superheavy nuclei. These calculations were performed using relativistic Hartree-Bogoliubov (RHB) formalism with separable pairing.

  1. Adiabatic fission barriers in superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Jachimowicz, P.; Kowal, M.; Skalski, J.

    2017-01-01

    Using the microscopic-macroscopic model based on the deformed Woods-Saxon single-particle potential and the Yukawa-plus-exponential macroscopic energy, we calculated static fission barriers Bf for 1305 heavy and superheavy nuclei 98 ≤Z ≤126 , including even-even, odd-even, even-odd and odd-odd systems. For odd and odd-odd nuclei, adiabatic potential-energy surfaces were calculated by a minimization over configurations with one blocked neutron or/and proton on a level from the 10th below to the 10th above the Fermi level. The parameters of the model that have been fixed previously by a fit to masses of even-even heavy nuclei were kept unchanged. A search for saddle points has been performed by the "imaginary water flow" method on a basic five-dimensional deformation grid, including triaxiality. Two auxiliary grids were used for checking the effects of the mass asymmetry and hexadecapole nonaxiality. The ground states (g.s.) were found by energy minimization over configurations and deformations. We find that the nonaxiality significantly changes first and second fission saddle in many nuclei. The effect of the mass asymmetry, known to lower the second, very deformed saddles in actinides, in the heaviest nuclei appears at the less deformed saddles in more than 100 nuclei. It happens for those saddles in which the triaxiality does not play any role, which suggests a decoupling between effects of the mass asymmetry and triaxiality. We studied also the influence of the pairing interaction strength on the staggering of Bf for odd- and even-particle numbers. Finally, we provide a comparison of our results with other theoretical fission barrier evaluations and with available experimental estimates.

  2. Transitional nuclei near shell closures

    SciTech Connect

    Mukherjee, G.

    2014-08-14

    High spin states in Bismuth and Thallium nuclei near the Z = 82 shell closure and Cesium nuclei near the N = 82 shell closure in A = 190 and A = 130 regions, respectively, have been experimentally investigated using heavy-ion fusion evaporation reaction and by detecting the gamma rays using the Indian National Gamma Array (INGA). Interesting shape properties in these transitional nuclei have been observed. The results were compared with the neighboring nuclei in these two regions. The total Routhian surface (TRS) calculations have been performed for a better understanding of the observed properties. In mass region A = 190, a change in shape from spherical to deformed has been observd around neutron number N = 112 for the Bi (Z = 83) isotopes with proton number above the magic gap Z = 82, whereas, the shape of Tl (Z = 81) isotopes with proton number below the magic gap Z = 82 remains stable as a function of neutron number. An important transition from aplanar to planar configuration of angular momentum vectors leading to the occurance of nuclar chirality and magnetic rotation, respectively, has been proposed for the unique parity πh{sub 11/2}⊗νh{sub 11/2} configuration in Cs isotopes in the mass region A ∼ 130 around neutron number N = 79. These results are in commensurate with the TRS calculations.

  3. Selfconsistent calculations for hyperdeformed nuclei

    SciTech Connect

    Molique, H.; Dobaczewski, J.; Dudek, J.; Luo, W.D.

    1996-12-31

    Properties of the hyperdeformed nuclei in the A {approximately} 170 mass range are re-examined using the self-consistent Hartree-Fock method with the SOP parametrization. A comparison with the previous predictions that were based on a non-selfconsistent approach is made. The existence of the {open_quotes}hyper-deformed shell closures{close_quotes} at the proton and neutron numbers Z=70 and N=100 and their very weak dependence on the rotational frequency is suggested; the corresponding single-particle energy gaps are predicted to play a role similar to that of the Z=66 and N=86 gaps in the super-deformed nuclei of the A {approximately} 150 mass range. Selfconsistent calculations suggest also that the A {approximately} 170 hyperdeformed structures have neglegible mass asymmetry in their shapes. Very importantly for the experimental studies, both the fission barriers and the {open_quotes}inner{close_quotes} barriers (that separate the hyperdeformed structures from those with smaller deformations) are predicted to be relatively high, up to the factor of {approximately}2 higher than the corresponding ones in the {sup 152}Dy superdeformed nucleus used as a reference.

  4. Exploration of High-Dimensional Nuclei Data

    SciTech Connect

    Fuentes, Fernando; Kettani, Houssain; Ostrouchov, George; Stoitsov, Mario; Nam, Hai Ah

    2010-01-01

    Density Functional Theory (DFT) provides the theoretical foundation for a self-consistent mean-field description of the nucleus in terms of one-body densities and currents. The idea is to construct a functional whose input is the proton and neutron densities and currents, and whose output yields the ground-state energy and other properties of the nucleus. Extensive computations of ground-state energies and other observable properties of several thousand nuclei are required in order to find a universal functional that covers the entire chart of nuclei. The analysis looks for hidden relationships between observables to determine a functional that can reliably predict nuclear properties in regions where no experimental data exist. Using methods for dimension reduction and visualization tools, it is hypothesized that the deformation of the neutrons is related to other characteristics of the nuclei. The discovered relationships with the deformation of the neutrons take us a step closer toward the universal functional.

  5. Test of Higgs couplings in e +e - colliders

    NASA Astrophysics Data System (ADS)

    Qinghai, Dai; Wengan, Ma; Yiaoyang, Liu

    1989-08-01

    A detailed analysis of the process e +e - → e +e - HH is presented. In addition to the S-channel, we investigated the T-channel, a process analogous to two-photon collisions in e +e - scattering. The couplings HH ZμZμ and HHH become important in the high √ S case. The measure of the process appears to be impossible if the Higgs boson is heavy.

  6. Superdeformation in the mercury nuclei

    SciTech Connect

    Janssens, R.V.F.; Carpenter, M.P.; Fernandez, P.B.; Moore, E.F.; Ahmad, I.; Khoo, T.L.; Wolfs, F.L.H. ); Drigert, M.W. ); Ye, D.; Beard, K.B.; Garg, U.; Reviol, W. ); Bearden, I.G.; Benet, P.; Daly, P.J.; Grabowski, Z.W. )

    1990-01-01

    We shall first summarize the present experimental situation concerning {sup 192}Hg, the nucleus regarded as the analog of {sup 152}Dy for this superdeformation (SD) region in that gaps are calculated to occur at large deformation for Z = 80 and N = 112. Proton and neutron excitations out of the {sup 192}Hg core will then be reviewed with particular emphasis on {sup 191}Hg and {sup 193}Tl. The presentation will conclude with a brief discussion on limits of the SD region for neutron deficient Hg nuclei. 26 refs., 10 figs.

  7. On the search for the η → e + e - decay at the VEPP-2000 e + e - collider

    NASA Astrophysics Data System (ADS)

    Achasov, M. N.; Barnyakov, A. Yu.; Beloborodov, K. I.; Berdyugin, A. V.; Bogdanchikov, A. G.; Botov, A. A.; Dimova, T. V.; Druzhinin, V. P.; Golubev, V. B.; Kardapoltsev, L. V.; Kharlamov, A. G.; Koop, I. A.; Korneev, L. A.; Korol, A. A.; Koshuba, S. V.; Kovrizhin, D. P.; Kupich, A. S.; Lysenko, A. P.; Martin, K. A.; Muchnoi, N. Yu.; Obrazovsky, A. E.; Pakhtusova, E. V.; Perevedentsev, E. A.; Rogovsky, Yu. A.; Senchenko, A. I.; Serednyakov, S. I.; Silagadze, Z. K.; Shatunov, Yu. M.; Shtol, D. A.; Shwartz, D. B.; Skrinsky, A. N.; Surin, I. K.; Tikhonov, Yu. A.; Usov, Yu. V.; Vasiljev, A. V.; Zemlyansky, I. M.

    2015-09-01

    The sensitivity of the VEPP-2000 e + e - collider in the search for the rare decay η → e + e - has been studied. The inverse reaction e + e - → η is proposed for this search. We have analyzed a data sample with an integrated luminosity of 108 nb-1 collected with the SND detector in the center-of-mass energy range 520-580 MeV and found no background events for the reaction e + e - → η in the decay mode η → π0π0π0. In the absence of background, a sensitivity to B(η → e + e -) of 10-6 can be reached during two weeks of VEPP-2000 operation. Such a sensitivity is higher than the current upper limit on B(η → e + e -) by a factor of 2.3.

  8. Evidence for higher order QED effects in e+ e- pair production at the BNL Relativistic Heavy Ion Collider.

    PubMed

    Baltz, A J

    2008-02-15

    A new lowest order QED calculation for BNL Relativistic Heavy-Ion Collider e+ e- pair production has been carried out with a phenomenological treatment of the Coulomb dissociation of the heavy-ion nuclei observed in the STAR ZDC triggers. The lowest order QED result for the experimental acceptance is nearly 2 standard deviations larger than the STAR data. A corresponding higher-order QED calculation is consistent with the data.

  9. The spectral function of 40Ar through the (e ,e' p) reaction

    NASA Astrophysics Data System (ADS)

    Day, Donal; E12-14-012 Collaboration

    2015-10-01

    Accelerator based neutrino-oscillation measurements, where neutrinos interact predominantly with nucleons bound in nuclei, demand an accurate description of the cross sections. Nuclear effects play a decisive role and are considered one of the main sources of systematic uncertainties. An effort is underway to develop theoretical models capable of a fully quantitative description of the neutrino-nucleus cross sections. An approach based on many body theory has proven successful in explaining electron-nucleus cross sections. The application of this approach to the analysis of neutrino interactions will require accurate models of the spectral functions for the nuclei in neutrino detectors. Of paramount importance is 40Ar, to be used in the Deep Underground Neutrino Experiment (DUNE, formerly LBNE). A 40Ar (e ,e' p) experiment which will prove indispensable for the construction of the argon spectral function has been approved at Jefferson Lab. The (e ,e' p) data, in addition, will advance theoretical developments, including the description of final-state interactions, unavoidable in neutrino experiments. The motivation, goals, experimental details and plans for the execution of this measurement will be discussed.

  10. Higher spin states in neutron rich nuclei

    NASA Astrophysics Data System (ADS)

    Zhu, S.; Zhao, X.; Hamilton, J. H.; Ramayya, A. V.; Ma, W. C.; Peker, L. K.; Kormicki, J.; Hong, X.; Gao, W. B.; Deng, J. K.

    Nuclei on the neutron rich side of beta stability have long been of interest for nuclear structure studies because they probe different regions of the single particle spectrum and different shell gap combinations for both spherical and deformed shapes. However, such nuclei have been a difficult challenge experimentally. Much information has been gained about the properties of neutron rich nuclei at low spin from the study of radioactive isotopes produced in neutron induced, and more recently, proton induced fission of uranium. Such studies have been made possible by the use of isotope separators on line to reactors and more recently to low energy proton accelerators. However, to test many of the theoretical predictions of nuclear models one needs information about the higher spin states in nuclei in addition to their low spin states populated in radioactive decays. Higher spin states in neutron rich nuclei have been an even more difficult challenge than the lower spin states accessible through decay studies. One cannot reach the higher spin states in these nuclei by heavy ion fusion evaporation in reactions as carried out extensively for proton rich nuclei. Many years ago prompt spontaneous fission studies were used to suggest for the first time that Sr-98 and Zr-100 had unusually large ground state of deformations. The availability of higher efficiency multi-detector arrays of Compton suppressed Ge detectors has brought on a renewed interest in studies of the prompt gamma rays of the fragments from spontaneous and induced fission. Groups at Argonne, Daresbury, and a Vanderbilt-Oak Ridge-Idaho-Dubna collaboration have carried out several such studies from spontaneous and heavy-ion induced fission which have revealed new insights into our knowledge of neutron rich nuclei. This paper is primarily a review of these studies, including recent, unpublished results.

  11. Search for the decay K L→ π0e +e -

    NASA Astrophysics Data System (ADS)

    Barr, G. D.; Clarke, P.; Coward, D.; Cundy, D.; Doble, N.; Gatignon, L.; Gibson, V.; Hagelberg, R.; Kesseler, G.; Van Der Lans, J.; Miczaika, T.; Nelson, H. N.; Steinberger, J.; Taureg, H.; Wahl, H.; Youngman, C.; Black, R.; Candlin, D. J.; Muir, J.; Peach, K. J.; Pijlgroms, B.; Shipsey, I. P.; Stephenson, W.; Blümer, H.; Heinz, R.; Kasemann, M.; Kleinknecht, K.; Mayer, P.; Panzer, B.; Renk, B.; Rohrer, H.; Augé, E.; Chase, R. L.; Corti, M.; Fournier, D.; Heusse, P.; Iconomidou-Fayard, L.; Harrus, I.; Lutz, A. M.; Sander, H. G.; Schaffer, A. C.; Bertanza, L.; Bigi, A.; Calafiura, P.; Calvetti, M.; Carosi, R.; Casali, R.; Cerri, C.; Mannelli, I.; Nappi, A.; Pierazzini, G. M.; Burkhardt, H.; Holder, M.; Quast, G.; Rost, M.; Weihs, W.; Zech, G.; CERN-Edinburgh-Mainz-Orsay-Pisa-Siegen Collaboration

    1988-11-01

    A search for the decay K L→ π0e +e - has been performed at the CERN SPS. One candidate event has been found, compatible with an expected background of 1.5 events. The corresponding upper limit for the branching ration is {Γ( KL→π 0e+e-) }/{Γ( KL → all)<4×10 -8} with 90% confidence.

  12. Searching for Short Range Correlations Using (e,e'NN) Reactions

    SciTech Connect

    Zhang, Bin

    2003-02-01

    Electron induced two nucleon knockout reactions (e,e'pp) and (e,e'np) were performed for 3He, 4He, and 12C nuclei with incident energies of 2.261 GeV and 4.461 GeV using the CLAS detector at Jefferson Lab. Events with missing momenta lower than the Fermi level and missing energies smaller than the pion threshold were studied. The residual system was assumed to be a spectator and the process was considered as a quasi-free knockout of an NN pair. The data showed that the initial momentum extends up to 800 MeV/c with considerable strength. The cross sections for 3He(e,e'pp)n were compared to the calculations of J.M. Laget. It was found that the final state interactions (FSI) and the meson exchange currents (MEC) dominate the cross sections and the short range properties of the NN pair were substantially undermined. However, the node of the S state wave function of the pp pair at around 400 MeV/c initial momentum starts to be recognizable in the 4.461 GeV data. The data and the theory suggest that with higher momentum transfers, especially in the region xBj > 1, the competing processes such as FSI and MEC will be less important and the detailed study of the short-range properties of nucleons inside nuclei will be more desirable.

  13. Regioselective synthesis and zone selective deprotection of [60]fullerene tris-adducts with an e,e,e addition pattern.

    PubMed

    Beuerle, Florian; Chronakis, Nikos; Hirsch, Andreas

    2005-08-07

    D(3h)-symmetrical tripodal tris(malonate) tethers have been used for the synthesis of [60]fullerene tris-adducts with an e,e,e addition pattern bearing topologically distinct polar and equatorial addend zones that can selectively be deprotected.

  14. Nuclei at High Angular Momentum

    SciTech Connect

    Diamond, R. M.; Stephens, F. S.

    1980-12-01

    It appears that most nuclei show a compromise between purely collective and purely non-collective behavior at very high spins.non~collective behavior in nuclei has been seen only as high as 36 or 37{bar h}, at which point a more collective structure seems to develop. The concepts underlying the study of high angular momentum states are discussed. The factors that limit angular momentum in nuclei are considered. The currently emerging state of physics of very high spin states is reviewed. The detailed calculations currently made for high spin states are described, focusing not on the calculations themselves, but on the physical input to them and results that come out. Production of high-spin states using heavy-ion reactions is reviewed. Studies of {gamma}-rays de-exciting the evaporation residues from heavy-ion reactions are covered. Two types of {gamma} rays occur: those that cool the nucleus to or toward the yrast line, called "statistical," and those that are more or less parallel to the yrast line and remove the angular momentum, called "yrast~like." Collective rotation, in simplest form the motion of a deformed nucleus around an axis perpendicular to its symmetry axis, is also covered.

  15. Nuclear vibrations and rotations of like nucleons in the same shell in even-even nuclei

    SciTech Connect

    Osman, A.; Allam, M.A.

    1987-01-01

    The vibrational and rotational motions in even nuclei are considered. A microscopic study of these motions leads to a relation between the vibrational motion in spherical nuclei and the rotational motion in deformed nuclei. Nuclei with like nucleons in the same shell are considered. The quadrupole two-body interactions are used in the large single j-shell of even nuclei. The energies and transition operators of nuclei in the nuclear rotational region are calculated using this microscopic method. Quadrupole moments are also calculated. These calculations are compared with the rotational model of the aligned coupling scheme. The present calculations are in good agreement with previous calculations.

  16. Ex Vivo Oxidation in Tissue and Plasma Assays of Hydroxyoctadecadienoates: (Z,E/E,E)-Stereoisomer Ratios

    PubMed Central

    Liu, Wei; Yin, Huiyong; Akazawa, Yoko Ogawa; Yoshida, Yasukazu; Niki, Etsuo; Porter, Ned A.

    2010-01-01

    The primary products from peroxidation of linoleate in biological tissues and fluids are the hydroperoxy octadecadienoates and the products normally assayed, after reduction of the hydroperoxides, are the corresponding hydroxy octadecadienoates (HODEs). The HODEs are found in tissues and fluids as a mixture of Z,E and E,E stereoisomers. Two regioisomeric sets of Z,E and E,E stereoisomers are normally observed with substitution at the 9 and 13 position of the 18-carbon chain. The Z,E/E,E product ratio has proved to be a useful means for assessing the reducing capacity of the medium undergoing peroxidation. The HODE Z,E/E,E product ratios previously reported for tissues such as liver and brain vary from 0.5 to 2.0 and plasma ratios are somewhat higher, between 2.0 and 3.0. The reported literature protocols for HODE assay in tissues involve homogenization, reduction with sodium borohydride in the presence of BHT, and ester hydrolysis with KOH to give the free HODEs. This is followed by either reverse-phase HPLC of the free acid HODEs or by conversion to TMS derivatives and GC/MS. When sodium borohydride is replaced in the protocol by triphenylphosphine, a gentler reducing agent, HODE Z,E/E,E product ratios are much higher and lower total HODEs levels of are found. It is proposed that inclusion of sodium borohydride in the isolation procedures leads to ex vivo reactions that are avoided if triphenylphosphine is used as the reducing agent. Modified protocols for HODE analyses (Tissue and Plasma Methods #2) are described that should be used for assays of tissues and fluids. PMID:20423158

  17. Charmonium production in e+e-→ψ+X(c cmacr ) and e+e-→D*DJ

    NASA Astrophysics Data System (ADS)

    Close, Frank; Downum, Clark

    2009-01-01

    The dominance of χ0 in the data for e+e-→ψ+χJ(c cmacr ) is shown to violate Okubo-Zweig-Iizuka rule factorization. Single gluon exchange gives a nonfactorizing effective S·L interaction that generates a large scalar production amplitude. This also has observable effects near threshold in e+e-→D(*)DJ, where enhancements of D*D0 and DD1 channels are predicted. Further tests and implications are discussed.

  18. Shell model for warm rotating nuclei

    SciTech Connect

    Matsuo, M.; Yoshida, K.; Dossing, T.

    1996-12-31

    Utilizing a shell model which combines the cranked Nilsson mean-field and the residual surface and volume delta two-body forces, the authors discuss the onset of rotational damping in normal- and super-deformed nuclei. Calculation for a typical normal deformed nucleus {sup 168}Yb indicates that the rotational damping sets in at around 0.8 MeV above the yrast line, and about 30 rotational bands of various length exists at a given rotational frequency, in overall agreement with experimental findings. It is predicted that the onset of rotational damping changes significantly in different superdeformed nuclei due to the variety of the shell gaps and single-particle orbits associated with the superdeformed mean-field.

  19. Nuclear and Q{sup 2} dependence of quaselastic (e,e{prime}p) scattering at large momentum transfer

    SciTech Connect

    Jackson, H.E.; Geesaman, D.F.; Jones, C.E.

    1995-08-01

    An experiment was completed at the Stanford Linear Accelerator Center in which measurements of the (e,e{prime}p) coincidence quasielastic cross section in nuclei were extended to the largest possible Q{sup 2} attainable with the Nuclear Physics Injector and the End Station A spectrometers. Coincidence measurements of the quasielastic (e,e{prime}p) cross section were made on nuclei from carbon to gold in the Q{sup 2} range of 1-7 (GeV/c){sup 2}. Several papers describing the results were published or submitted. Analysis of the data is in its final stages. In summary, the cross section for quasielastic {sup 12}C(e,e{prime}p) scattering was measured at momentum transfer Q{sup 2}=1, 3, 5, and 6.8 (GeV/c){sup 2}. The results are consistent with scattering from a single nucleon as the dominant process. The nuclear transparency is obtained and compared with theoretical calculations that incorporate color transparency effects. No significant rise of the transparency with Q{sup 2} is observed. Cross sections were reported for the reaction {sup 2}H(e,e{prime}p)n for momentum transfers in the range 1.2 {<=}Q{sup 2}{<=}6.8 (GeV/c){sup 2} and for missing momenta from 0 to 250 MeV/c. The longitudinal-transverse interference structure function was separated at Q{sup 2}=1.5 (GeV/c){sup 2}. The observables were compared to calculations performed in nonrelativistic and relativistic frameworks. The data are best described by a fully relativistic calculation. The A-dependence of the quasielastic A(e,e{prime}p) reaction was studied with {sup 2}H, C, Fe, and Au nuclei at momentum transfers Q{sup 2}=1, 3, 5, and 6.8 (GeV/c){sup 2}. The nuclear transparency T A,Q{sup 2}, a measure of the average probability that the struck proton escapes from the nucleu A without interaction, was extracted. Several calculations predict a significant increase in T with momentum transfer, a phenomenon known as color transparency. No significant rise within errors is seen for any of the nuclei studied.

  20. Measurement of Nuclear Transparency from A(e,e',π+) Reactions

    SciTech Connect

    Clasie, Benjamin

    2006-08-01

    We have measured the nuclear transparency of the A(e, e' π+) process in 2H,12C, 27Al, 63Cu and 197Au targets. These measurements were performed at the Jefferson Laboratory over a four momen- tum transfer squared range Q2 = 1.1 to 4.7 (GeV/c)2. The nuclear transparency was extracted as the super-ratio of ( σA/ σH) from data to a model of pion-electroproduction from nuclei without N final state interactions. The Q2 and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations, and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency.

  1. Intrinsic excitations in doubly odd nuclei

    SciTech Connect

    Sood, P.C.

    1985-01-15

    A procedure is outlined for predicting the bandhead energies of the two-particle (intrinsic) states of odd-odd deformed nuclei based on a quantitative evaluation of the zero range n-p residual interaction energy. We present our results for 250Bk, where many such levels are experimentally known, and for 236Np and 246Am, where the information is very scarce and that too uncertain, to illustrate the effectiveness of this approach.

  2. Reaction e+e-→D¯D and ψ' mesons

    NASA Astrophysics Data System (ADS)

    Limphirat, A.; Sreethawong, W.; Khosonthongkee, K.; Yan, Y.

    2014-03-01

    We study the reaction e+e-→D¯D near threshold in the P30 nonrelativistic quark model, including as intermediate states the J /ψ, ψ(2S), ψ(3770), and ψ(4040) mesons. The work reveals that experimental data strongly favor one of the two ψ(2S)-ψ(3770) mixing angles derived by fitting to the e-e+ partial decay widths of the ψ(2S) and ψ(3770) mesons. The meson X(3940) as well as the resonance around 3.9 GeV observed by the Belle and BABAR Collaborations in the reaction e+e-→D¯D is unlikely to be a cc¯ IG(JPC)=0-(1--) state.

  3. Exact diagonalization of the Bohr Hamiltonian for rotational nuclei: Dynamical {gamma} softness and triaxiality

    SciTech Connect

    Caprio, M. A.

    2011-06-15

    Detailed quantitative predictions are obtained for phonon and multiphonon excitations in well-deformed rotor nuclei within the geometric framework, by exact numerical diagonalization of the Bohr Hamiltonian in an SO(5) basis. Dynamical {gamma} deformation is found to significantly influence the predictions through its coupling to the rotational motion. Basic signatures for the onset of rigid triaxial deformation are also obtained.

  4. Open s d -shell nuclei from first principles

    NASA Astrophysics Data System (ADS)

    Jansen, G. R.; Schuster, M. D.; Signoracci, A.; Hagen, G.; Navrátil, P.

    2016-07-01

    We extend the ab initio coupled-cluster effective interaction (CCEI) method to open-shell nuclei with protons and neutrons in the valence space and compute binding energies and excited states of isotopes of neon and magnesium. We employ a nucleon-nucleon and three-nucleon interaction from chiral effective field theory evolved to a lower cutoff via a similarity renormalization group transformation. We find good agreement with experiment for binding energies and spectra, while charge radii of neon isotopes are underestimated. For the deformed nuclei 20Ne and 24Mg, we reproduce rotational bands and electric quadrupole transitions within uncertainties estimated from an effective field theory for deformed nuclei, thereby demonstrating that collective phenomena in s d -shell nuclei emerge from complex ab initio calculations.

  5. Open sd-shell nuclei from first principles

    SciTech Connect

    Jansen, Gustav R.; Signoracci, Angelo J.; Hagen, Gaute; Navratil, Petr

    2016-07-05

    We extend the ab initio coupled-cluster effective interaction (CCEI) method to open-shell nuclei with protons and neutrons in the valence space, and compute binding energies and excited states of isotopes of neon and magnesium. We employ a nucleon-nucleon and three-nucleon interaction from chiral effective field theory evolved to a lower cutoff via a similarity renormalization group transformation. We find good agreement with experiment for binding energies and spectra, while charge radii of neon isotopes are underestimated. For the deformed nuclei 20Ne and 24Mg we reproduce rotational bands and electric quadrupole transitions within uncertainties estimated from an effective field theory for deformed nuclei, thereby demonstrating that collective phenomena in sd-shell nuclei emerge from complex ab initio calculations.

  6. Open sd-shell nuclei from first principles

    DOE PAGES

    Jansen, Gustav R.; Signoracci, Angelo J.; Hagen, Gaute; ...

    2016-07-05

    We extend the ab initio coupled-cluster effective interaction (CCEI) method to open-shell nuclei with protons and neutrons in the valence space, and compute binding energies and excited states of isotopes of neon and magnesium. We employ a nucleon-nucleon and three-nucleon interaction from chiral effective field theory evolved to a lower cutoff via a similarity renormalization group transformation. We find good agreement with experiment for binding energies and spectra, while charge radii of neon isotopes are underestimated. For the deformed nuclei 20Ne and 24Mg we reproduce rotational bands and electric quadrupole transitions within uncertainties estimated from an effective field theory formore » deformed nuclei, thereby demonstrating that collective phenomena in sd-shell nuclei emerge from complex ab initio calculations.« less

  7. Structure and symmetries of odd-odd triaxial nuclei

    NASA Astrophysics Data System (ADS)

    Palit, R.; Bhat, G. H.; Sheikh, J. A.

    2017-05-01

    Rotational spectra of odd-odd Rh and Ag isotopes are investigated with the primary motivation to search for the spontaneous chiral symmetry breaking phenomenon in these nuclei. The experimental results obtained on the degenerate dipole bands of some of these isotopes using a large array of gamma detectors are discussed and studied using the triaxial projected shell (TPSM) approach. It is shown that, first of all, to reproduce the odd-even staggering of the known yrast bands of these nuclei, large triaxial deformation is needed. This large triaxial deformation also gives rise to doublet band structures in many of these studied nuclei. The observed doublet bands in these isotopes are shown to be reproduced reasonably well by the TPSM calculations. Further, the TPSM calculations for neutron-rich nuclei indicate that the ideal manifestation of the chirality can be realised in 106Rh and 112Ag , where the doublet bands have similar electromagnetic properties along with small differences in excitation energies.

  8. Anomaly of the moment of inertia of shape transitional nuclei

    SciTech Connect

    Gupta, J. B.; Hamilton, J. H.

    2011-06-15

    The change in the structure of the collective levels with spin angular momentum in atomic nuclei is often expressed in terms of the classical concepts of the kinematic and the dynamic moments of inertia varying with spin. For the well deformed even-even nuclei the kinematic moment of inertia increases with spin up to 10%-20%, at say I{sup {pi}} = 12{sup +}. However, for the shape transitional nuclei, or almost spherical nuclei, it increases with spin much faster. The pitfalls of using the rotor model form of kinematic moment of inertia in such cases are pointed out here. Alternative methods of extracting the nuclear structure information are explored. The important role of the ground state deformation is illustrated. The use of the power index formula for evaluating the effective moment of inertia, free from the assumption of the rotor model, is described.

  9. Open sd-shell nuclei from first principles

    SciTech Connect

    Jansen, Gustav R.; Signoracci, Angelo J.; Hagen, Gaute; Navratil, Petr

    2016-07-05

    We extend the ab initio coupled-cluster effective interaction (CCEI) method to open-shell nuclei with protons and neutrons in the valence space, and compute binding energies and excited states of isotopes of neon and magnesium. We employ a nucleon-nucleon and three-nucleon interaction from chiral effective field theory evolved to a lower cutoff via a similarity renormalization group transformation. We find good agreement with experiment for binding energies and spectra, while charge radii of neon isotopes are underestimated. For the deformed nuclei 20Ne and 24Mg we reproduce rotational bands and electric quadrupole transitions within uncertainties estimated from an effective field theory for deformed nuclei, thereby demonstrating that collective phenomena in sd-shell nuclei emerge from complex ab initio calculations.

  10. Approximate Coulomb distortion effects in (e,e{sup {prime}}p) reactions

    SciTech Connect

    Kim, K.S.; Wright, L.E.

    1997-07-01

    In this paper we apply a well-tested approximation of electron Coulomb distortion effects to the exclusive reaction (e,e{sup {prime}}p) in the quasielastic region. We compare the approximate treatment of Coulomb distortion effects to the exact distorted wave Born approximation evaluated by means of partial wave analysis to gauge the quality of our approximate treatment. We show that the approximate Mo/ller potential has a plane-wave-like structure and hence permits the separation of the cross section into five terms which depend on bilinear products of transforms of the transition four current elements. These transforms reduce to Fourier transforms when Coulomb distortion is not present, but become modified with the inclusion of Coulomb distortion. We investigate the application of the approximate formalism to a model of {sup 208}Pb(e,e{sup {prime}}p) using Dirac-Hartree single particle wave functions for the ground state and relativistic optical model wave functions for the continuum proton. We show that it is still possible to extract, albeit with some approximation, the various structure functions from the experimentally measured data even for heavy nuclei. {copyright} {ital 1997} {ital The American Physical Society}

  11. E.E.G. and Personality Factors in Baby Batterers

    PubMed Central

    Smith, Selwyn M.; Honigsberger, Leo; Smith, Carol A.

    1973-01-01

    Out of 35 parents who battered their children eight had an abnormal E.E.G. All of these were found to be psychopathic, of low intelligence, and to be persistent batterers. The presence of an abnormal E.E.G. strongly suggests that some baby batterers are more closely related to those who commit acts of violence and that taken as a whole they are not a homogenous group about whom it is safe to generalize. The possibility of a separate subgroup among baby batterers, therefore, needs close attention. PMID:4717420

  12. Active galactic nuclei

    PubMed Central

    Fabian, Andrew C.

    1999-01-01

    Active galactic nuclei are the most powerful, long-lived objects in the Universe. Recent data confirm the theoretical idea that the power source is accretion into a massive black hole. The common occurrence of obscuration and outflows probably means that the contribution of active galactic nuclei to the power density of the Universe has been generally underestimated. PMID:10220363

  13. Fast electric dipole transitions in Ra-Ac nuclei

    SciTech Connect

    Ahmad, I.

    1985-01-01

    Lifetime of levels in /sup 225/Ra, /sup 225/Ac, and /sup 227/Ac have been measured by delayed coincidence techniques and these have been used to determine the E1 gamma-ray transition probabilities. The reduced E1 transition probabilities. The reduced E1 transition probabilities in /sup 225/Ra and /sup 225/Ac are about two orders of magnitude larger than the values in mid-actinide nuclei. On the other hand, the E1 rate in /sup 227/Ac is similar to those measured in heavier actinides. Previous studies suggest the presence of octupole deformation in all the three nuclei. The present investigation indicates that fast E1 transitions occur for nuclei with octupole deformation. However, the studies also show that there is no one-to-one correspondence between E1 rate and octupole deformation. 13 refs., 4 figs.

  14. Evidence for short range corelations from high Q{sup 2} (e,e{prime}) reactions

    SciTech Connect

    Strikman, M.I.; Frankfurt, L.L.; Sargayan, M.M.

    1994-04-01

    For many years now short-range correlations (SRC) in nuclei have been considered as an essential feature of the nuclear wave function. At high energy (e,e{prime}) reactions, where Q{sup 2} > 1 (GeV/c){sup 2}, x = Q{sup 2}/2mq{sub o} > 1 and 1 GeV > q{sub o}> 300 {approximately} 400 MeV the scattering from low momentum nucleons is kinematically suppressed and there the evidence of SRC expected to be more prominent. These reactions have been intensively investigated during the last decade or so at SLAC on both light and heavy nuclei. The above kinematics allows one to compute the cross section through the processes local in space. To explain this the authors analyse the representation of the cross section as a Fourier transform of the commutator of electromagnetic currents and see that the major contribution in the cross section is given by the region of integration.

  15. Population of Nuclei Via 7Li-Induced Binary Reactions

    SciTech Connect

    Clark, Rodney M.; Phair, Larry W.; Descovich, M.; Cromaz, Mario; Deleplanque, M.A.; Fall on, Paul; Lee, I-Yang; Macchiavelli, A.O.; McMahan, Margaret A.; Moretto, Luciano G.; Rodriguez-Vieitez, E.; Sinha,Shrabani; Stephens, Frank S.; Ward, David; Wiedeking, Mathis

    2005-08-08

    The authors have investigated the population of nuclei formed in binary reactions involving {sup 7}Li beams on targets of {sup 160}Gd and {sup 184}W. The {sup 7}Li + {sup 184}W data were taken in the first experiment using the LIBERACE Ge-array in combination with the STARS Si {Delta}E-E telescope system at the 88-Inch Cyclotron of the Lawrence Berkeley National Laboratory. By using the Wilczynski binary transfer model, in combination with a standard evaporation model, they are able to reproduce the experimental results. This is a useful method for predicting the population of neutron-rich heavy nuclei formed in binary reactions involving beams of weakly bound nuclei formed in binary reactions involving beams of weakly bound nuclei and will be of use in future spectroscopic studies.

  16. Angular distribution of {alpha} particles from oriented {sup 253,254}Es and {sup 255}Fm nuclei

    SciTech Connect

    Severijns, N.; Golovko, V.V.; Kraev, I.S.; Phalet, T.; Belyaev, A.A.; Lukhanin, A.A.; Noga, V.I.; Erzinkyan, A.L.; Parfenova, V.P.; Eversheim, P.-D.; Herzog, P.; Tramm, C.; Filimonov, V.T.; Toporov, Yu.G.; Zotov, E.; Gurevich, G.M.; Rusakov, A.V.; Vyachin, V.N.; Zakoucky, D.

    2005-04-01

    The anisotropy in the angular distribution of {alpha} particles from oriented {sup 253,254}Es and {sup 255}Fm nuclei, which are among the strongest deformed {alpha} emitters, was measured. Large {alpha} anisotropies have been observed for all three nuclei. The results are compared with calculations based on {alpha}-particle tunneling through a deformed Coulomb barrier.

  17. e+e- → charm cross sections via ISR

    NASA Astrophysics Data System (ADS)

    Pakhlova, Galina

    2010-06-01

    We discuss recent measurements of exclusive e+e- cross sections for charmed hadron final states near threshold performed by Belle and BABAR. The results are based on a study of events with initial-state-radiation photons in a large data sample collected with the Belle and BABAR detectors at the γ(4S) resonance and nearby continuum.

  18. Isolation of Nuclei.

    PubMed

    Nabbi, Arash; Riabowol, Karl

    2015-08-03

    The isolation of nuclei is often the first step in studying processes such as nuclear-cytoplasmic shuttling, subcellular localization of proteins, and protein-chromatin or nuclear protein-protein interactions in response to diverse stimuli. Therefore, rapidly obtaining nuclei from cells with relatively high purity and minimal subcellular contamination, protein degradation, or postharvesting modification is highly desirable. Historically, the isolation of nuclei involved a homogenization step followed by centrifugation through high-density glycerol or sucrose. Although clean nuclei with little cytoplasmic contamination can be prepared using this method, it is typically time consuming and can allow protein degradation, protein modification, and leaching of components from the nuclei to occur. We have developed a rapid and simple fractionation method that is based on the selective dissolution of the cytoplasmic membrane (but not the nuclear membrane) using a low concentration of a nonionic detergent and rapid centrifugation steps. Here we describe important considerations when isolating nuclei from cells, introduce our rapid method, and compare this method to a more traditional protocol for isolating nuclei, noting the strengths and limitations of each approach.

  19. Analysis of isomeric ratios for medium-mass nuclei

    NASA Astrophysics Data System (ADS)

    Danagulyan, A. S.; Hovhannisyan, G. H.; Bakhshiyan, T. M.; Kerobyan, I. A.

    2016-09-01

    Values of the isomeric ratios for product nuclei originating from simple charge-exchange reactions were analyzed. The cross sections for the formation of product nuclei in ground and isomeric states were calculated with the aid of the TALYS 1.4 and EMPIRE 3.2 codes. The calculated values of the isomeric ratios were compared with their experimental counterparts taken from the EXFOR database. For the 86,87Y, 94,95,96,99Tc, and 44Sc nuclei, the experimental values of the isomeric ratios exceed the respective calculated values. The nuclei in question feature weak deformations and have high-spin yrast lines and rotational bands. The possible reason behind the discrepancy between theoretical and experimental isomeric ratios is that the decay of yrast states leads with a high probability to the formation of isomeric states of detected product nuclei.

  20. Analysis of isomeric ratios for medium-mass nuclei

    SciTech Connect

    Danagulyan, A. S.; Hovhannisyan, G. H. Bakhshiyan, T. M.; Kerobyan, I. A.

    2016-09-15

    Values of the isomeric ratios for product nuclei originating from simple charge-exchange reactions were analyzed. The cross sections for the formation of product nuclei in ground and isomeric states were calculated with the aid of the TALYS 1.4 and EMPIRE 3.2 codes. The calculated values of the isomeric ratios were compared with their experimental counterparts taken from the EXFOR database. For the {sup 86,87}Y, {sup 94,95,96,99}Tc, and {sup 44}Sc nuclei, the experimental values of the isomeric ratios exceed the respective calculated values. The nuclei in question feature weak deformations and have high-spin yrast lines and rotational bands. The possible reason behind the discrepancy between theoretical and experimental isomeric ratios is that the decay of yrast states leads with a high probability to the formation of isomeric states of detected product nuclei.

  1. Microscopic analysis of pear-shaped nuclei

    NASA Astrophysics Data System (ADS)

    Nomura, K.

    2015-10-01

    We analyze the quadrupole-octupole collective states based on the microscopic energy density functional framework. By mapping the deformation constrained self-consistent axially symmetric mean-field energy surfaces onto the equivalent Hamiltonian of the sd f interacting boson model (IBM), that is, onto the energy expectation value in the boson coherent state, the Hamiltonian parameters are determined. The resulting IBM Hamiltonian is used to calculate excitation spectra and transition rates for the positive- and negative-parity collective states in nuclei characteristic for octupole deformation and collectivity. Consistently with the empirical trend, the microscopic calculation based on the systematics of β2 - β3 energy maps, the resulting low-lying negative-parity bands and transition rates show evidence of a shape transition between stable octupole deformation and octupole vibrations characteristic for β3-soft potentials.

  2. Madelung Deformity.

    PubMed

    Kozin, Scott H; Zlotolow, Dan A

    2015-10-01

    Madelung deformity of the wrist is more common in females and is often associated with Leri Weill dyschondrosteosis, a mesomelic form of dwarfism. Patients with Madelung deformity often report wrist deformity resulting from the prominence of the relatively long ulna. The typical Madelung deformity is associated with a Vickers ligament that creates a tether across the volar-ulnar radial physis that restricts growth across this segment. The distal radius deforms in the coronal (increasing radial inclination) and the sagittal (increasing volar tilt) planes. There is lunate subsidence and the proximal carpal row adapts to the deformity by forming an upside-down pyramid shape or triangle. Treatment depends on the age at presentation, degree of deformity, and magnitude of symptoms. Mild asymptomatic deformity warrants a period of nonsurgical management with serial x-ray examinations because the natural history is unpredictable. Many patients never require surgical intervention. Progressive deformity in the young child with considerable growth potential remaining requires release of Vickers ligament and radial physiolysis to prevent ongoing deterioration Concomitant ulnar epiphysiodesis may be necessary. Advanced asymptomatic deformity in older children with an unacceptable-appearing wrist or symptomatic deformity are indications for surgery. A dome osteotomy of the radius allows 3-dimensional correction of the deformity. Positive radiographic and clinical results after dome osteotomy have been reported. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  3. Alpha-induced reaction cross-section for Sm, U, Np targets: influence of hexadecapole deformation and deformed surface diffuseness

    NASA Astrophysics Data System (ADS)

    Alavi, S. A.; Dehghani, V.

    2017-06-01

    Alpha-induced reactions on 154Sm, 233,235,236,238U, and 237Np deformed nuclei are studied theoretically. The effects of hexadecapole deformation, deformed surface diffuseness parameter, and orientation on barrier height and position, fusion cross-section at any angle, and fusion cross-section have been investigated. Both hexadecapole deformation and deformed surface diffuseness can affect barrier characteristics and enhance fusion cross-section. Good agreement between experimental data and theoretical calculations with quadrupole and hexadecapole deformation and deformed surface diffuseness were observed for the 4He+154Sm, 235U, 237Np reactions.

  4. Investigation of decay modes and stability effects on Spectral Statistics of different nuclei

    NASA Astrophysics Data System (ADS)

    Sabri, H.; Malekzadeh, R.

    2017-07-01

    In this paper, the spectral statistics of 482 stable and radioactive nuclei in the 10 ≤ A ≤ 250 mass region are considered with emphasis on nearest neighbor spacing statistics. The sequences are constructed by using all the available empirical data for considered nuclei in different categories and analyzed via Maximum Likelihood estimation technique in the framework of Abul-Magd distribution. The results offer more regular dynamics for stable nuclei in comparison with unstable nuclei and there are suggestions of the effects due to the radioactivity types, mass, quadrupole deformation and also on the more chaotic dynamics of unstable nuclei.

  5. Ground state properties of superheavy nuclei with Z=117 and Z=119

    SciTech Connect

    Ren Zhongzhou; Chen Dinghan; Xu Chang

    2006-11-02

    We review the current studies on the ground-state properties of superheavy nuclei. It is shown that there is shape coexistence for the ground state of many superheavy nuclei from different models and many superheavy nuclei are deformed. This can lead to the existence of isomers in superheavy region and it plays an important role for the stability of superheavy nuclei. Some new results on Z=117 and Z=119 isotopes are presented. The agreement between theoretical results and experimental data clearly demonstrates the validity of theoretical models for the ground-state properties of superheavy nuclei.

  6. Exotic Light Nuclei

    ERIC Educational Resources Information Center

    Cerny, Joseph; Poskanzer, Arthur M.

    1978-01-01

    Among the light elements, nuclei with unequal numbers of protons and neutrons are highly unstable. Some survive just long enough to be detected and exhibit unusual regimes of radioactive decay. ( Autor/MA)

  7. Exotic Light Nuclei

    ERIC Educational Resources Information Center

    Cerny, Joseph; Poskanzer, Arthur M.

    1978-01-01

    Among the light elements, nuclei with unequal numbers of protons and neutrons are highly unstable. Some survive just long enough to be detected and exhibit unusual regimes of radioactive decay. ( Autor/MA)

  8. Observations of cometary nuclei

    NASA Astrophysics Data System (ADS)

    A'Hearn, M. F.

    Attempts to observe cometary nuclei and to determine fundamental physical parameters relevant to the relationship between comets and asteroids are reviewed. It has been found that cometary nuclei, at least of periodic comets, are bigger and blacker than generally thought as recently as five years ago. Geometric albedos may be typically three percent and typical radii are probably of order 5 km. Nuclei of periodic comets are probably highly prolate unless they are both oblate and rotating about one of the major axes. P/Halley images provide convincing evidence of the existence of mantles discussed in many models. Numerous pieces of evidence suggest a connection between cometary nuclei and A-A asteroids of types D and C.

  9. Allowance for the shell structure of colliding nuclei in the fusion-fission process

    SciTech Connect

    Litnevsky, V. L.; Kosenko, G. I.; Ivanyuk, F. A.; Pashkevich, V. V.

    2011-07-15

    The motion of two nuclei toward each other in fusion-fission reactions is considered. The state of the system of interacting nuclei is specified in terms of three collective coordinates (parameters). These are the distance between the centers of mass of the nuclei and the deformation parameter for each of them (the nose-to-nose orientation of the nuclei is assumed). The evolution of collective degrees of freedom of the system is described by Langevin equations. The energies of the Coulomb and nuclear (Gross-Kalinovsky potential) interactions of nuclei are taken into account in the potential energy of the system along with the deformation energy of each nucleus with allowance for shell effects. The motion of nuclei toward each other are calculated for two reaction types: reactions involving nuclei that are deformed ({sub 42}{sup 100}Mo + {sub 42}{sup 100}Mo {yields} {sub 84}{sup 200}Po) and those that are spherical ({sub 82}{sup 208}Pb + {sub 8}{sup 18}O {yields} {sub 90}{sup 226}Th) in the ground state. It is shown that the shell structure of interacting nuclei affects not only the fusion process as a whole (fusionbarrier height and initial-reaction-energy dependence of the probability that the nuclei involved touch each other) but also the processes occurring in each nucleus individually (shape of the nuclei and their excitation energies at the point of touching).

  10. Hypernuclear Spectroscopy using the (e,e'K+) Reaction

    SciTech Connect

    Yuan, Lulin; Sarsour, Murad; Miyoshi, Toshinobu; Zhu, Zhengmao; Ahmidouch, Abdellah; Androic, Darko; Angelescu, Tatiana; Asaturyan, Razmik; Avery, Steven; Baker, O.; Bertovic, I.; Breuer, Herbert; Carlini, Roger; Cha, Jinseok; Chrien, Robert; Christy, Michael; Cole, Leon; Danagoulian, Samuel; Dehnhard, Dietrich; Elaasar, Mostafa; Empl, A.; Ent, Rolf; Fenker, Howard; Fujii, Yu; Furic, Miroslav; Gan, Liping; Garrow, Kenneth; Gasparian, Ashot; Gueye, Paul; Harvey, Mark; Hashimoto, Osamu; Hinton, Wendy; Hu, Bitao; Hungerford, Ed; Jackson, Caesar; Johnston, Kathleen; Juengst, Henry; Keppel, Cynthia; Lan, Kejian; Liang, Yongguang; LIKHACHEV, V.; Likhachev, V.; Liu, Jinghua; Mack, David; Margaryan, Amur; Markowitz, Pete; Mkrtchyan, Hamlet; Nakamura, Satoshi; Petkovic, Tomislav; Reinhold, Joerg; Roche, Julie; Sato, Yoshinori; Sawafta, Reyad; Simicevic, Neven; Smith, G.; Stepanyan, Samuel; Tadevosyan, Vardan; Takahashi, Toshiyuki; Tanida, K.; Tang, Liguang; Ukai, Mifuyu; Uzzle, Alicia; Vulcan, William; Wells, Steven; Wood, Stephen; Xu, Guanghua; Yamaguchi, Hiroshi

    2006-04-01

    A pioneering experiment in Lambda hypernuclear spectroscopy, undertaken at the Thomas Jefferson National Accelerator Facility (Jlab), was recently reported. The experiment used the high- precision, continuous electron beam at Jlab, and a special arrangement of spectrometer magnets to measure the spectrum from {nat}C and 7Li targets using the (e,e' K+)reaction. The 12B hypernuclear spectrum was previously published. This experiment is now reported in more detail, with improved results for the 12B hypernuclear spectrum. In addition, unpublished results of the 7He hypernuclear spectrum are also shown. This later spectrum indicates the need for a more detailed few-body calculation of the hypernucleus and the reaction process. The success of this experiment demonstrates that the (e,e'K+) reaction can be effectively used as a high resolution tool to study hypernuclear spectra, ant its use should be vigorously pursued.

  11. Monte Carlo calculations of (e,e{prime}p) reactions

    SciTech Connect

    Pieper, S.C.; Pandharipande, V.R.; Boffi, S.; Radici, M.

    1995-08-01

    We have used our {sup 16}O Monte Carlo program to compute the p{sub 3/2} quasihole wave function in {sup 16}O and the Pavia program to compute {sup 16}O(e,e{prime}p) {sup 15}N(3/2{sup -}) with this wave function. We also developed a local-density approximation (LDA) for obtaining the quasihole wave function from a mean-field wave function, and studied the effects of using this LDA on the outgoing distorted waves. We find that we can predict correctly the contribution of the interior of the nucleus to the observed (e,e{prime}p) cross sections, but the surface contribution is too large. The LDA modifications to the outgoing wave function are small.

  12. Hypernuclear spectroscopy using the (e,e'K{sup +}) reaction

    SciTech Connect

    Yuan, L.; Zhu, X.; Avery, S.; Cha, J.; Christy, M.; Cole, L.; Danagoulian, S.; Gan, L.; Gasparian, A.; Gueye, P.; Harvey, M.; Hinton, W.; Hu, B.; Jackson, C.; Keppel, C.; Liang, Y.; Liu, J. H.; Uzzle, A.; Sarsour, M.; Empl, A.

    2006-04-15

    A pioneering experiment in {lambda} hypernuclear spectroscopy, undertaken at the Thomas Jefferson National Accelerator Facility (J Lab), was recently reported. The experiment used the high precision, continuous electron beam at JLab, and a special arrangement of spectrometer magnets to measure the hypernuclear spectrum from C and {sup 7}Li targets using the (e,e'K{sup +}) reaction. The {sub {lambda}}{sup 12}B spectrum found in this investigation was previously published, but is reported here in more detail, with improved resolution. In addition, the results of a {sub {lambda}}{sup 7}He spectrum also obtained in the experiment, are shown. This latter spectrum indicates the need for a more detailed few-body calculation of the hypernucleus and the reaction process. The success of the experiment demonstrates the potential of the (e,e'K{sup +}) reaction for high resolution spectroscopy of hypernuclear spectra.

  13. Cluster Features of Normal-, Super- and Hyperdeformed nuclei

    SciTech Connect

    Adamian, G.G.; Antonenko, N.V.; Kuklin, S.N.

    2005-11-21

    It is shown that an important mode of nuclear excitations in different processes like as cluster radioactivity, parity splitting in normal deformed bands, decay out phenomenon of the yrast superdeformed states in the heavy nuclei and formation of super- and hyper-deformed states in induced fission and heavy ion reactions is related to the motion in charge (mass) asymmetry coordinate. With the suggested cluster model one can try to unify all phenomena mentioned above.

  14. SiW ECAL for future e+e- collider

    NASA Astrophysics Data System (ADS)

    Balagura, V.; Bilokin, S.; Bonis, J.; Boudry, V.; Brient, J.-C.; Callier, S.; Cheng, T.; Cornat, R.; De La Taille, C.; Doan, T. H.; Frotin, M.; Gastaldi, F.; Hirai, H.; Jain, S.; Jain, Sh.; Lacour, D.; Lavergne, L.; Lleres, A.; Magniette, F.; Mastrolorenzo, L.; Nanni, J.; Poeschl, R.; Pozdnyakov, A.; Psallidas, A.; Ruan, M.; Rubio-Roy, M.; Seguin-Moreau, N.; Shpak, K.; Suehara, T.; Thiebault, A.; Wright, J.; Yu, D.

    2017-07-01

    Calorimeters with silicon detectors have many unique features and are proposed for several world-leading experiments. We discuss the tests of the first three 18×18 cm2 layers segmented into 1024 pixels of the technological prototype of the silicon-tungsten electromagnetic calorimeter for a future e+e- collider. The tests have beem performed in November 2015 at CERN SPS beam line.

  15. Three pseudoscalar meson production in e+e- annihilation

    SciTech Connect

    Dai, Lingyun; Portoles, Jorge; Shekhovtsova, Olga

    2013-09-01

    We study, at leading order in the large number of colours expansion and within the Resonance Chiral Theory framework, the odd-intrinsic-parity $e^+ e^- \\rightarrow \\pi^+ \\pi^- (\\pi^0 , \\eta)$ cross-sections in the energy regime populated by hadron resonances, namely $9 \\, m_{\\pi}^2 \\lsim E \\lsim 2 \\, \\mbox{GeV}$. In addition we implement our results in the Monte Carlo generator PHOKHARA 7.0 and we simulate hadron production through the radiative return method.

  16. e-/e+ Accelerating Structure with Cyclic Variation of Azimuth Asymmetry

    SciTech Connect

    Krasnykh, A.; /SLAC

    2007-03-05

    A classical electron/positron accelerating structure is a disk-loaded cylindrical waveguide. The accelerator structure here has azimuth symmetry. The proposed structure contains a disk-loaded cylindrical waveguide where there is a periodical change of RF-field vs. azimuth. The modulation deforms the rf-field in such a manner that the accelerated particles undergo transverse focusing forces. The new class of accelerator structures covers the initial part of e+/e- linacs where a bunch is not rigid and additional transverse focusing fields are necessary. We discuss a bunch formation with a high transverse aspect ratio in the proposed structure and particularly in the photoinjector part of a linac.

  17. Observation of η'→ω e+e-

    NASA Astrophysics Data System (ADS)

    Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Ferroli, R. Baldini; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; de Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Duan, P. F.; Eren, E. E.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Fava, L.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. Y.; Gao, Y.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, X. Q.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. M.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang, Y.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. W.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kiese, P.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kühn, W.; Kupsc, A.; Lange, J. S.; Lara, M.; Larin, P.; Leng, C.; Li, C.; Li, Cheng; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. M.; Li, X. N.; Li, X. Q.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B. J.; Liu, C. X.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Maas, F. E.; Maggiora, M.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales, C. Morales; Moriya, K.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Prasad, V.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ripka, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Santoro, V.; Sarantsev, A.; Savrié, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, S. G.; Wang, W.; Wang, X. F.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, Z.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, L.; Xu, Q. J.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. N.; Zhang, Y. H.; Zhang, Y. T.; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zotti, L.; Zou, B. S.; Zou, J. H.; Besiii Collaboration

    2015-09-01

    Based on a sample of η' mesons produced in the radiative decay J /ψ →γ η' in 1.31 ×109 J /ψ events collected with the BESIII detector, the decay η'→ω e+e- is observed for the first time, with a statistical significance of 8 σ . The branching fraction is measured to be B (η'→ω e+e-)=(1.97 ±0.34 (stat)±0.17 (syst))×10-4 , which is in agreement with theoretical predictions. The branching fraction of η'→ω γ is also measured to be (2.55 ±0.03 (stat)±0.16 (syst))×10-2 , which is the most precise measurement to date, and the relative branching fraction B/(η'→ω e+e-) B (η'→ω γ ) is determined to be (7.71 ±1.34 (stat)±0.54 (syst))×10-3 .

  18. Search for Long-Lived Particles in e+ e- Collisions.

    PubMed

    Lees, J P; Poireau, V; Tisserand, V; Grauges, E; Palano, A; Eigen, G; Stugu, B; Brown, D N; Kerth, L T; Kolomensky, Yu G; Lee, M J; Lynch, G; Koch, H; Schroeder, T; Hearty, C; Mattison, T S; McKenna, J A; So, R Y; Khan, A; Blinov, V E; Buzykaev, A R; Druzhinin, V P; Golubev, V B; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Lankford, A J; Dey, B; Gary, J W; Long, O; Campagnari, C; Franco Sevilla, M; Hong, T M; Kovalskyi, D; Richman, J D; West, C A; Eisner, A M; Lockman, W S; Panduro Vazquez, W; Schumm, B A; Seiden, A; Chao, D S; Cheng, C H; Echenard, B; Flood, K T; Hitlin, D G; Miyashita, T S; Ongmongkolkul, P; Porter, F C; Röhrken, M; Andreassen, R; Huard, Z; Meadows, B T; Pushpawela, B G; Sokoloff, M D; Sun, L; Bloom, P C; Ford, W T; Gaz, A; Smith, J G; Wagner, S R; Ayad, R; Toki, W H; Spaan, B; Bernard, D; Verderi, M; Playfer, S; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Fioravanti, E; Garzia, I; Luppi, E; Piemontese, L; Santoro, V; Calcaterra, A; de Sangro, R; Finocchiaro, G; Martellotti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Contri, R; Lo Vetere, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Bhuyan, B; Prasad, V; Adametz, A; Uwer, U; Lacker, H M; Mallik, U; Chen, C; Cochran, J; Prell, S; Ahmed, H; Gritsan, A V; Arnaud, N; Davier, M; Derkach, D; Grosdidier, G; Le Diberder, F; Lutz, A M; Malaescu, B; Roudeau, P; Stocchi, A; Wormser, G; Lange, D J; Wright, D M; Coleman, J P; Fry, J R; Gabathuler, E; Hutchcroft, D E; Payne, D J; Touramanis, C; Bevan, A J; Di Lodovico, F; Sacco, R; Cowan, G; Brown, D N; Davis, C L; Denig, A G; Fritsch, M; Gradl, W; Griessinger, K; Hafner, A; Schubert, K R; Barlow, R J; Lafferty, G D; Cenci, R; Hamilton, B; Jawahery, A; Roberts, D A; Cowan, R; Sciolla, G; Cheaib, R; Patel, P M; Robertson, S H; Neri, N; Palombo, F; Cremaldi, L; Godang, R; Sonnek, P; Summers, D J; Simard, M; Taras, P; De Nardo, G; Onorato, G; Sciacca, C; Martinelli, M; Raven, G; Jessop, C P; LoSecco, J M; Honscheid, K; Kass, R; Feltresi, E; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simi, G; Simonetto, F; Stroili, R; Akar, S; Ben-Haim, E; Bomben, M; Bonneaud, G R; Briand, H; Calderini, G; Chauveau, J; Leruste, Ph; Marchiori, G; Ocariz, J; Biasini, M; Manoni, E; Pacetti, S; Rossi, A; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Casarosa, G; Cervelli, A; Chrzaszcz, M; Forti, F; Giorgi, M A; Lusiani, A; Oberhof, B; Paoloni, E; Perez, A; Rizzo, G; Walsh, J J; Lopes Pegna, D; Olsen, J; Smith, A J S; Anulli, F; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Pilloni, A; Piredda, G; Bünger, C; Dittrich, S; Grünberg, O; Hess, M; Leddig, T; Voß, C; Waldi, R; Adye, T; Olaiya, E O; Wilson, F F; Emery, S; Vasseur, G; Aston, D; Bard, D J; Cartaro, C; Convery, M R; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Ebert, M; Field, R C; Fulsom, B G; Graham, M T; Hast, C; Innes, W R; Kim, P; Leith, D W G S; Lindemann, D; Luitz, S; Luth, V; Lynch, H L; MacFarlane, D B; Muller, D R; Neal, H; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Snyder, A; Su, D; Sullivan, M K; Va'vra, J; Wisniewski, W J; Wulsin, H W; Purohit, M V; White, R M; Wilson, J R; Randle-Conde, A; Sekula, S J; Bellis, M; Burchat, P R; Puccio, E M T; Alam, M S; Ernst, J A; Gorodeisky, R; Guttman, N; Peimer, D R; Soffer, A; Spanier, S M; Ritchie, J L; Schwitters, R F; Wray, B C; Izen, J M; Lou, X C; Bianchi, F; De Mori, F; Filippi, A; Gamba, D; Lanceri, L; Vitale, L; Martinez-Vidal, F; Oyanguren, A; Villanueva-Perez, P; Albert, J; Banerjee, Sw; Beaulieu, A; Bernlochner, F U; Choi, H H F; King, G J; Kowalewski, R; Lewczuk, M J; Lueck, T; Nugent, I M; Roney, J M; Sobie, R J; Tasneem, N; Gershon, T J; Harrison, P F; Latham, T E; Band, H R; Dasu, S; Pan, Y; Prepost, R; Wu, S L

    2015-05-01

    We present a search for a neutral, long-lived particle L that is produced in e+ e- collisions and decays at a significant distance from the e+ e- interaction point into various flavor combinations of two oppositely charged tracks. The analysis uses an e+ e- data sample with a luminosity of 489.1  fb(-1) collected by the BABAR detector at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and just below the ϒ(4S). Fitting the two-track mass distribution in search of a signal peak, we do not observe a significant signal, and set 90% confidence level upper limits on the product of the L production cross section, branching fraction, and reconstruction efficiency for six possible two-body L decay modes as a function of the L mass. The efficiency is given for each final state as a function of the mass, lifetime, and transverse momentum of the candidate, allowing application of the upper limits to any production model. In addition, upper limits are provided on the branching fraction B(B→XsL), where Xs is a strange hadronic system.

  19. Halos in a deformed relativistic Hartree-Bogoliubov theory in continuum

    SciTech Connect

    Li Lulu; Meng Jie; Ring, P.; Zhao Enguang; Zhou Shangui

    2012-10-20

    In this contribution we present some recent results about neutron halos in deformed nuclei. A deformed relativistic Hartree-Bogoliubov theory in continuumhas been developed and the halo phenomenon in deformed weakly bound nuclei is investigated. These weakly bound quantum systems present interesting examples for the study of the interdependence between the deformation of the core and the particles in the halo. Magnesium and neon isotopes are studied and detailed results are presented for the deformed neutron-rich and weakly bound nuclei {sup 42}Mg. The core of this nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the existence of halos in deformed nuclei and for the occurrence of this decoupling effect are discussed.

  20. Bohr Hamiltonian with a deformation-dependent mass term for the Davidson potential

    SciTech Connect

    Bonatsos, Dennis; Georgoudis, P. E.; Lenis, D.; Minkov, N.; Quesne, C.

    2011-04-15

    Analytical expressions for spectra and wave functions are derived for a Bohr Hamiltonian, describing the collective motion of deformed nuclei, in which the mass is allowed to depend on the nuclear deformation. Solutions are obtained for separable potentials consisting of a Davidson potential in the {beta} variable, in the cases of {gamma}-unstable nuclei, axially symmetric prolate deformed nuclei, and triaxial nuclei, implementing the usual approximations in each case. The solution, called the deformation-dependent mass (DDM) Davidson model, is achieved by using techniques of supersymmetric quantum mechanics (SUSYQM), involving a deformed shape invariance condition. Spectra and B(E2) transition rates are compared to experimental data. The dependence of the mass on the deformation, dictated by SUSYQM for the potential used, reduces the rate of increase of the moment of inertia with deformation, removing a main drawback of the model.

  1. The quest for novel modes of excitation in exotic nuclei

    NASA Astrophysics Data System (ADS)

    Paar, N.

    2010-06-01

    This paper provides an insight into several open problems in the quest for novel modes of excitation in nuclei with isospin asymmetry, deformation and finite-temperature characteristics in stellar environments. Major unsolved problems include the nature of pygmy dipole resonances, the quest for various multipole and spin-isospin excitations both in neutron-rich and proton drip-line nuclei mainly driven by loosely bound nucleons, excitations in unstable deformed nuclei and evolution of their properties with the shape phase transition. Exotic modes of excitation in nuclei at finite temperatures characteristic of supernova evolution present open problems with a possible impact in modeling astrophysically relevant weak interaction rates. All these issues challenge self-consistent many-body theory frameworks at the frontiers of on-going research, including nuclear energy density functionals, both phenomenological and constrained by the strong interaction physics of QCD, models based on low-momentum two-nucleon interaction Vlow-k and correlated realistic nucleon-nucleon interaction VUCOM, supplemented by three-body force, as well as two-nucleon and three-nucleon interactions derived from the chiral effective field theory. Joined theoretical and experimental efforts, including research with radioactive isotope beams, are needed to provide insight into dynamical properties of nuclei away from the valley of stability, involving the interplay of isospin asymmetry, deformation and finite temperature.

  2. Recent results on giant dipole resonance decays in highly excited nuclei

    SciTech Connect

    Snover, K.A.

    1991-12-31

    Some recent results on Giant Dipole Resonance (GDR) decays in highly excited, equilibrated nuclei, are discussed based primarily on work done at Seattle. Four sections address the following topics: oblate shapes of rotating, highly excited Zr--Mo nuclei; adiabatic versus `motionally narrowed` GDR decay; large spin-driven deformations observed in hot medium-mass nuclei; and search for entrance channel effects in GDR decay following {sup 58}Ni {plus} {sup 92}Zr fusion. 22 refs.

  3. Recent results on giant dipole resonance decays in highly excited nuclei

    SciTech Connect

    Snover, K.A.

    1991-01-01

    Some recent results on Giant Dipole Resonance (GDR) decays in highly excited, equilibrated nuclei, are discussed based primarily on work done at Seattle. Four sections address the following topics: oblate shapes of rotating, highly excited Zr--Mo nuclei; adiabatic versus motionally narrowed' GDR decay; large spin-driven deformations observed in hot medium-mass nuclei; and search for entrance channel effects in GDR decay following [sup 58]Ni [plus] [sup 92]Zr fusion. 22 refs.

  4. Delayed and In-beam Spectroscopy on Francium and Astatine Nuclei at the Proton Drip Line

    NASA Astrophysics Data System (ADS)

    Uusitalo, J.; Jakobsson, U.

    2011-11-01

    Delayed and in-beam spectroscopy on francium and astatine nuclei at and beyond the proton drip line has been performed. In neutron deficient astatine nuclei a shift to deformed shapes as a function of decreasing neutron has been obtained. In neutron deficient francium isotope the same shift is evident.

  5. Delayed and In-beam Spectroscopy on Francium and Astatine Nuclei at the Proton Drip Line

    SciTech Connect

    Uusitalo, J.; Jakobsson, U.; Collaboration: RITU-Gamma Gollaboration

    2011-11-30

    Delayed and in-beam spectroscopy on francium and astatine nuclei at and beyond the proton drip line has been performed. In neutron deficient astatine nuclei a shift to deformed shapes as a function of decreasing neutron has been obtained. In neutron deficient francium isotope the same shift is evident.

  6. Separation of e+e- → e+e- and e+e- → π+π- events based on the difference in the energy deposition profiles in SND detector calorimeter.

    NASA Astrophysics Data System (ADS)

    Achasov, M. N.; Kupich, A. S.

    2017-06-01

    The technique of discrimination of the e+e- → e+e- and e+e- → π+π- events in energy range 0.5 < √s < 1 GeV based on the difference in the energy deposition in calorimeter of SND detector was developed by applying machine learning method. Identification efficiency for e+e- → e+e- and e+e- → π+π- events is estimated to be in the range from 99.3 to 99.8%. Contribution of the identification efficiencies errors to the total error of e+e- → π+π- cross section is less than 0.2% for the most energy points.

  7. Radiations from hot nuclei

    NASA Technical Reports Server (NTRS)

    Malik, F. Bary

    1993-01-01

    The investigation indicates that nuclei with excitation energy of a few hundred MeV to BeV are more likely to radiate hot nuclear clusters than neutrons. These daughter clusters could, furthermore, de-excite emitting other hot nuclei, and the chain continues until these nuclei cool off sufficiently to evaporate primarily neutrons. A few GeV excited nuclei could radiate elementary particles preferentially over neutrons. Impact of space radiation with materials (for example, spacecraft) produces highly excited nuclei which cool down emitting electromagnetic and particle radiations. At a few MeV excitation energy, neutron emission becomes more dominant than gamma-ray emission and one often attributes the cooling to take place by successive neutron decay. However, a recent experiment studying the cooling process of 396 MeV excited Hg-190 casts some doubt on this thinking, and the purpose of this investigation is to explore the possibility of other types of nuclear emission which might out-compete with neutron evaporation.

  8. Survey of Reflection-Asymmetric Nuclear Deformations

    NASA Astrophysics Data System (ADS)

    Olsen, Erik; Birge, Noah; Erler, Jochen; Nazarewicz, Witek; Perhac, Alex; Schunck, Nicolas; Stoitsov, Mario; Nuclei Collaboration

    2015-10-01

    Due to spontaneous symmetry breaking it is possible for a nucleus to have a deformed shape in its ground state. It is theorized that atoms whose nuclei have reflection-asymmetric or pear-like deformations could have non-zero electric dipole moments (EDMs). Such a trait would be evidence of CP-violation, a feature that goes beyond the Standard Model of Physics. It is the purpose of this project to predict which nuclei exhibit a reflection-asymmetric deformation and which of those would be the best candidates for an EDM measuring experiment. Using nuclear Density Functional Theory along with the new computer code AxialHFB and massively parallel computing we calculated ground state nuclear properties for thousands of even-even nuclei across the nuclear chart: from light to superheavy and from stable to short-lived systems. Six different Energy Density Functionals (EDFs) were used to assess systematic errors in our calculations. Overall, 140 even-even nuclei (near and among the lantanides and actinides and in the superheavy region near N = 184) were predicted by all 6 EDFs to have a pear-like deformation. The case of 112Xe also proved curious as it was predicted by 5 EDFs to have a pear-like deformation despite its proximity to the two-proton drip line. Deceased.

  9. Constraints on axions from π0 --> e+e- decay

    NASA Astrophysics Data System (ADS)

    Massó, Eduard

    1986-12-01

    The contribution of axions to π0 --> e+e- decay is considered. It is found that a recently proposed short-lived axion with a mass of 1.8 MeV induces a decay rate inconsistent with experimental observations. More generally, upper limits are placed on the mass of an axion that couples to first-generations fermions. On leave of absence from Department de Física Teòrica, Universitat Autònoma de Barcelona, Bellaterra, Spain.

  10. Two-particle distributions in e+e- jets

    NASA Astrophysics Data System (ADS)

    Willen, Dennis E.

    1980-04-01

    We apply the "jet calculus" of Konishi, Ukawa, and Veneziano (KUV) to the two-particle spectra of e+e- jets. This computation uses single-particle fragmentation functions and the KUV analysis of leading logarithms to predict the multiparticle spectra entirely from the single-particle data. The effects of charm and heavier flavors are discussed and a simple prescription for inverting the necessary double moments is given. The double-differential cross section dσdx1dx2 is displayed for various combinations of mesons and the antiproton.

  11. Direct photon production in e+e- annihilation

    NASA Astrophysics Data System (ADS)

    Fernandez, E.; Ford, W. T.; Qi, N.; Read, A. L.; Smith, J. G.; Camporesi, T.; de Sangro, R.; Marini, A.; Peruzzi, I.; Piccolo, M.; Ronga, F.; Blume, H. T.; Hurst, R. B.; Sleeman, J. C.; Venuti, J. P.; Wald, H. B.; Weinstein, Roy; Band, H. R.; Gettner, M. W.; Goderre, G. P.; Meyer, O. A.; Moromisato, J. H.; Shambroom, W. D.; von Goeler, E.; Ash, W. W.; Chadwick, G. B.; Clearwater, S. H.; Coombes, R. W.; Kaye, H. S.; Lau, K. H.; Leedy, R. E.; Lynch, H. L.; Messner, R. L.; Moss, L. J.; Muller, F.; Nelson, H. N.; Ritson, D. M.; Rosenberg, L. J.; Wiser, D. E.; Zdarko, R. W.; Groom, D. E.; Lee, H. Y.; Delfino, M. C.; Heltsley, B. K.; Johnson, J. R.; Lavine, T. L.; Maruyama, T.; Prepost, R.

    1985-01-01

    Direct photon production in hadronic events from e+e- annihilation has been studied at √s =29 GeV with use of the MAC detector at the PEP storage ring. A charge asymmetry A=(-12.3+/-3.5)% is observed in the final-state jets. The cross section and the charge asymmetry are in good agreement with the predictions of the fractionally charged quark-parton model. Both the charge asymmetry and total yield have been used to determine values of quark charges. Limits have been established for anomalous sources of direct photons.

  12. Search for Superheavy Nuclei

    NASA Astrophysics Data System (ADS)

    Hamilton, J. H.; Hofmann, S.; Oganessian, Y. T.

    2013-10-01

    We describe the discoveries of new superheavy nuclei (a) with Z=107-112 produced in cold fusion reactions between 208Pb and 209Bi and beams of A > 50 and (b) with Z=113-118 in hot fusion reactions between actinide nuclei and 48Ca. We also discuss the facilities used in these measurements. We compare the behavior of the β-decay energies and half-lives, spontaneous fission half-lives, cross sections, and excitation functions with expectations from theoretical calculations. Finally, we outline future research directions, including studies of the detailed properties of nuclei synthesized at higher yields, searches for new elements with Z=119 and 120, and developments of new facilities.

  13. Scattering Of Light Nuclei

    SciTech Connect

    Quaglioni, S; Navratil, P; Roth, R

    2009-12-15

    The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. Above all nuclear scattering and reactions, which require the solution of the many-body quantum-mechanical problem in the continuum, represent an extraordinary theoretical as well as computational challenge for ab initio approaches.We present a new ab initio many-body approach which derives from the combination of the ab initio no-core shell model with the resonating-group method [4]. By complementing a microscopic cluster technique with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters, this approach is capable of describing simultaneously both bound and scattering states in light nuclei. We will discuss applications to neutron and proton scattering on sand light p-shell nuclei using realistic nucleon-nucleon potentials, and outline the progress toward the treatment of more complex reactions.

  14. Study of the process e+e-→n n ¯ at the VEPP-2000 e+e- collider with the SND detector

    NASA Astrophysics Data System (ADS)

    Achasov, M. N.; Barnyakov, A. Yu.; Beloborodov, K. I.; Berdyugin, A. V.; Berkaev, D. E.; Bogdanchikov, A. G.; Botov, A. A.; Dimova, T. V.; Druzhinin, V. P.; Golubev, V. B.; Kardapoltsev, L. V.; Kasaev, A. S.; Kharlamov, A. G.; Kirpotin, A. N.; Koop, I. A.; Korol, A. A.; Koshuba, S. V.; Kovrizhin, D. P.; Kupich, A. S.; Martin, K. A.; Obrazovsky, A. E.; Pakhtusova, E. V.; Rogovsky, Yu. A.; Senchenko, A. I.; Serednyakov, S. I.; Silagadze, Z. K.; Shatunov, Yu. M.; Shtol, D. A.; Shwartz, D. B.; Skrinsky, A. N.; Surin, I. K.; Tikhonov, Yu. A.; Usov, Yu. V.; Vasiljev, A. V.

    2014-12-01

    The process e+e-→n n ¯ has been studied at the VEPP-2000 e+e- collider with the SND detector in the energy range from threshold up to 2 GeV. As a result of the experiment, the e+e-→n n ¯ cross section and effective neutron form factor have been measured.

  15. Microscopic description of α decay from superdeformed nuclei

    NASA Astrophysics Data System (ADS)

    Delion, D. S.; Liotta, R. J.

    1998-10-01

    A microscopic formalism to treat α decay from superdeformed nuclei is given within the framework of the Hartree-Fock-Bogoliubov approximation. The process of penetration through the deformed barrier is described exactly. The influence of the deformation on the formation amplitude and on the penetrability is analyzed. It is found that the results of the WKB approximation differ strongly from the exact ones as the deformation increases for β2 larger than 0.3. The most favorable case that we found corresponds to a superdeformed band in 192Pb, for which the α decay probability is very large, making this a likely mechanism to feed the daughter nucleus 188Hg.

  16. The shapes of nuclei

    NASA Astrophysics Data System (ADS)

    Bertsch, G. F.

    Gerry Brown initiated some early studies on the coexistence of different nuclear shapes. The subject has continued to be of interest and is crucial for understanding nuclear fission. We now have a very good picture of the potential energy surface with respect to shape degrees of freedom in heavy nuclei, but the dynamics remain problematic. In contrast, the early studies on light nuclei were quite successful in describing the mixing between shapes. Perhaps a new approach in the spirit of the old calculations could better elucidate the character of the fission dynamics and explain phenomena that current theory does not model well.

  17. Disintegration of comet nuclei

    NASA Astrophysics Data System (ADS)

    Ksanfomality, Leonid V.

    2012-02-01

    The breaking up of comets into separate pieces, each with its own tail, was seen many times by astronomers of the past. The phenomenon was in sharp contrast to the idea of the eternal and unchangeable celestial firmament and was commonly believed to be an omen of impending disaster, especially for comets with tails stretching across half the sky. It is only now that we have efficient enough space exploration tools to see comet nuclei and even - in the particular case of small comet Hartley-2 in 2010 - to watch their disintegration stage. There are also other suspected candidates for disintegration in the vast family of comet nuclei and other Solar System bodies.

  18. Signal of doubly charged Higgs at e+e- colliders

    NASA Astrophysics Data System (ADS)

    Hue, L. T.; Huong, D. T.; Long, H. N.; Hung, H. T.; Thao, N. H.

    2015-11-01

    The masses and signals of the production of doubly charged Higgses (DCH) in the framework of the supersymmetric reduced minimal 3-3-1 model are investigated. In the DCH sector, we prove that there always exists a region of the parameter space where the mass of the lightest DCH is of the order of O(100) GeV even when all other new particles are very heavy. The lightest DCH mainly decays to two same-sign leptons while the dominant decay channels of the heavy DCHs are those decaying to heavy particles. We analyze each production cross section for e^+e^- ⇒ H^{++} H^{-} as a function of a few kinematic variables, which are useful to discuss the creation of DCHs in e^+e^- colliders as an indicator of new physics beyond the Standard Model. A numerical study shows that the cross sections for creating the lightest DCH can reach values of a few pb. The other two DCHs are too heavy, beyond the observable range of experiments. The lightest DCH may be detected by the International Linear Collider or the Compact Linear Collider by searching for its decay to a same-sign charged lepton pair.

  19. Dark photon search at a circular e+e- collider

    NASA Astrophysics Data System (ADS)

    He, Min; He, Xiao-Gang; Huang, Cheng-Kai

    2017-08-01

    One of the interesting portals linking a dark sector and the Standard Model (SM) is the kinetic mixing between the SM U(1)Y field with a new dark photon A‧ from a U(1)A‧ gauge interaction. Stringent limits have been obtained for the kinetic mixing parameter 𝜖 through various processes. In this work, we study the possibility of searching for a dark photon interaction at a circular e+e- collider through the process e+e-→ γA‧→ γμ+μ-. We find that the constraint on 𝜖2 for dark photon mass in the few tens of GeV range, assuming that the μ+μ- invariant mass can be measured to an accuracy of 0.5% mA‧, can be better than 3 × 10-6 for the proposed CEPC with a 10-year running at 3σ (statistic) level, and better than 2 × 10-6 for FCC-ee with even just one-year running at s = 240GeV, better than the LHCb, ATLAS, CMS experiments and other facilities can do in a similar dark photon mass range. For FCC-ee, running at s = 160GeV, the constraint can be even better.

  20. Collider phenomenology of e-e-→W-W-

    NASA Astrophysics Data System (ADS)

    Wang, Kai; Xu, Tao; Zhang, Liangliang

    2017-04-01

    The Majorana nature of neutrinos is one of the most fundamental questions in particle physics. It is directly related to the violation of accidental lepton number symmetry. This motivated enormous efforts into the search of such processes; among them, one conventional experiment is the neutrinoless double-beta decay (0 ν β β ). On the other hand, there have been proposals of future electron-positron colliders as a "Higgs factory" for the precise measurement of Higgs boson properties, and it has been proposed to convert such a machine into an electron-electron collider. This option enables a new way to probe TeV Majorana neutrinos via the inverse 0 ν β β decay process (e-e-→W-W- ) as an alternative and complementary test to the conventional 0 ν β β decay experiments. In this paper, we investigate the collider search for e-e-→W-W- in different decay channels at future electron colliders. We find that the pure hadronic channel, the semileptonic channel with a muon, and the pure leptonic channel with a dimuon have the most discovery potential.

  1. Deformed proximity potential for heavy ion reactions

    SciTech Connect

    Baltz, A.J.

    1989-09-01

    The proximity potential is discussed for the inelastic scattering of a spherical nucleus on a deformed nucleus or the mutual interaction of two deformed nuclei. It is shown that the proximity potential is, in general, geometrically more correct than the usual centerline prescription used in inelastic scattering analyses. For the cases where the proximity potential is inadequate a folding model approach is advocated. Techniques to facilitate the coupled channels analysis are presented. 11 refs., 6 figs.

  2. High spin spectroscopy for A approx 160 nuclei

    SciTech Connect

    Yu, C.-H. Tennessee Univ., Knoxville, TN . Dept. of Physics and Astronomy); Gascon, J.; Garrett, J.D.; Hagemann, G.B. )

    1989-01-01

    Experimental routhians, alignments, band crossing frequencies, and the B(M1)/B(E2) ratios of the N = 90 isotopes and several light Lu (N = 90--96) isotopes are summarized and discussed in terms of shape changes. These systematic analyses show a neutron and proton number dependent deformations (both quadruple and {gamma} deformations) for these light rare earth nuclei. The stability of the nuclear deformation with respect to {beta} and {gamma} is also found to be particle number dependent. Such particle number dependent shapes can be attributed to the different locations of the proton and neutron Fermi levels in the Nilsson diagrams. Configurations dependent shapes are discussed specially concerned the deformation difference between the proton h{sub 9/2}1/2{sup -}(541) and the high-K h{sub 11/2} configurations. The observed large neutron band crossing frequencies in the h{sub 9/2}1/2{sup -}(541) configuration support the predicted large deformation of this configuration but can be reproduced by the cranked shell model calculation according to the predicted deformations. Lifetime measurement for {sup 157}Ho, one of the nuclei that show a large {h bar}{omega}{sup c} in the 1/2{sup -}(541) band, indicates that deformation difference can only account for 20% of such shift in {h bar}{omega}{sub c}. 55 refs., 12 figs.

  3. Population of Nuclei Via 7Li-Induced Binary Reactions

    SciTech Connect

    Clark, R M; Phair, L W; Descovich, M; Cromaz, M; Deleplanque, M A; Fallon, P; Lee, I Y; Macchiavelli, A O; McMahan, M A; Moretto, L G; Rodriguez-Vieitez, E; Sinha, S; Stephens, F S; Ward, D; Wiedeking, M; Bernstein, L A; Burke, J T; Church, J A

    2005-08-09

    The authors have investigated the population of nuclei formed in binary reactions involving {sup 7}Li beams on targets of {sup 160}Gd and {sup 184}W. The {sup 7}Li + {sup 184}W data were taken in the first experiment using the LIBERACE Ge-array in combination with the STARS Si {Delta}E-E telescope system at the 88-Inch Cyclotron of the Lawrence Berkeley National Laboratory. By using the Wilczynski binary transfer model, in combination with a standard evaporation model, they are able to reproduce the experimental results. This is a useful method for predicting the population of neutron-rich heavy nuclei formed in binary reactions involving beams of weakly bound nuclei and will be of use in future spectroscopic studies.

  4. Physics with Polarized Nuclei.

    ERIC Educational Resources Information Center

    Thompson, William J.; Clegg, Thomas B.

    1979-01-01

    Discusses recent advances in polarization techniques, specifically those dealing with polarization of atomic nuclei, and how polarized beams and targets are produced. These techniques have greatly increased the scope of possible studies, and provided the tools for testing fundamental symmetries and the spin dependence of nuclear forces. (GA)

  5. The scission point configuration of fissioning nuclei

    NASA Astrophysics Data System (ADS)

    Ivanyuk, Fedir

    2016-06-01

    We define the optimal shape which fissioning nuclei attain just before the scission and calculate the deformation energy as function of the mass asymmetry at the scission point. The calculated deformation energy is used in quasi-static approximation for the estimation of mass distribution, total kinetic and excitation energy of fission fragments, and the total number of prompt neutrons. The calculated results reproduce rather well the experimental data on the position of the peaks in the mass distribution of fission fragments, the total kinetic and excitation energy of fission fragments. The calculated value of neutron multiplicity is somewhat larger than experimental results. The saw-tooth structure of neutron multiplicity is qualitatively reproduced.

  6. Fission of actinide nuclei using multi-nucleon transfer reactions

    NASA Astrophysics Data System (ADS)

    Léguillon, Romain; Nishio, Katsuhisa; Hirose, Kentaro; Orlandi, Riccardo; Makii, Hiroyuki; Nishinaka, Ichiro; Ishii, Tetsuro; Tsukada, Kazuaki; Asai, Masato; Chiba, Satoshi; Ohtsuki, Tsutomu; Araki, Shohei; Watanabe, Yukinobu; Tatsuzawa, Ryotaro; Takaki, Naoyuki

    2014-09-01

    We are promoting a campaign to measure fission-fragment mass distributions for neutron-rich actinide nuclei populated by transfer reactions from their ground state up to an excitation energy of several tens MeV. We thus obtain the excitation energy dependence of the mass distribution. The experiment was carried out at the 20 MV JAEA tandem facility at Tokai. We report on the data obtained in the direct reaction 18 O + 232 Th . Transfer-channels and excitation energies of the fissioning nuclei were identified using silicon dE-E detectors located at forward angle. Two fission fragments were detected in coincidence using multi-wire proportional counters. Fission fragment masses were determined by kinematic consideration. We obtained the fission fragment mass distributions for 13 nuclei from actinium to uranium and some fission barrier heights. We are promoting a campaign to measure fission-fragment mass distributions for neutron-rich actinide nuclei populated by transfer reactions from their ground state up to an excitation energy of several tens MeV. We thus obtain the excitation energy dependence of the mass distribution. The experiment was carried out at the 20 MV JAEA tandem facility at Tokai. We report on the data obtained in the direct reaction 18 O + 232 Th . Transfer-channels and excitation energies of the fissioning nuclei were identified using silicon dE-E detectors located at forward angle. Two fission fragments were detected in coincidence using multi-wire proportional counters. Fission fragment masses were determined by kinematic consideration. We obtained the fission fragment mass distributions for 13 nuclei from actinium to uranium and some fission barrier heights. Present study is supported by the Ministry of Education, Culture, Sports, Science and Technology of Japan.

  7. Isotopic Dependence of the Shape of Se Nuclei in the Collective-Model Representation

    SciTech Connect

    Davidovskaya, O.I.; Kashuba, I.E.; Porodzinsky, Yu.V.

    2005-06-01

    The energy structure of low-lying excited states in the nuclei of even selenium isotopes is considered on the basis of a soft-nucleus model. The nuclei are treated as nonaxial rotors, longitudinal and transverse vibrations of their surface being taken into account in the quadrupole-deformation approximation featuring an admixture of an octupole deformation. The parameters of a phenomenological collective model for the {sup 72,74,76,78,80,82}Se nuclei are found both in the case of {beta} vibrations (longitudinal vibrations) and in the presence of additional {gamma} vibrations (transverse vibrations) of the nuclear surface.

  8. Further examination of prolate-shape dominance in nuclear deformation

    SciTech Connect

    Hamamoto, Ikuko; Mottelson, Ben R.

    2009-03-15

    The observed almost complete dominance of prolate over oblate deformations in the ground states of deformed even-even nuclei is related to the splitting of high l''surface'' orbits in the Nilsson diagram: on the oblate side the occurrence of numerous strongly avoided crossings which reduce the fanning out of the low {lambda} orbits, while on the prolate side the same interactions increase the fanning out. It is further demonstrated that the prolate dominance is rather special for the restricted particle number of available nuclei and is not generic for finite systems with mean-field potentials resembling those in atomic nuclei.

  9. The three-jet rate in e+e- annihilation

    NASA Astrophysics Data System (ADS)

    Lovett-Turner, C. N.

    1994-06-01

    Progress has been made on the calculation of R3, the three-jet rate in e+e- annihilation, in the k⊥ (Durham) scheme. Using the coherent branching formalism [A.H. Mueller, Phys. Lett. B 104 (1981) 161; B.I. Ermolaev and V.S. Fadin, JETP Lett. 33 (1981) 285; Yu.L. Dokshitzer, V.S. Fadin and V.A. Khoze, Z. Phys. C 15 (1982) 325; C 18 (1983) 37; A. Bassetto, M. Ciafaloni and G. Marchesini, Phys. Rep. 100 (1983) 202; Yu.L. Dokshitzer and S. Troyan, Leningrad Report LNPI-922 (1984); Yu.L. Dokshitzer, V.A. Khoze and S. Troyan, in: Perturbative QCD, ed. A.H. Mueller (World Scientific, Singapore, 1989)], an explicit expression for R3 is calculated. In this, leading and next-to-leading large logarithms (LL and NLL) are resummed to all orders in QCD perturbation theory. In addition to exponentials an error function is involved.

  10. Collins Effect from Polarized SIDIS and e+e- Data

    SciTech Connect

    Prokudin, A.; Tuerk, C.

    2007-06-13

    The recent data on the transverse single spin asymmetry A{sub UT}{sup sin({phi}{sub h}+{phi}{sub S})} from HERMES and COMPASS Collaborations are analysed within LO parton model with unintegrated parton distribution and fragmentation functions. A fit of SIDIS data from HERMES Collaboration is performed leading to the extraction of favoured and unfavoured Collins fragmentation functions. A very good description of COMPASS data is obtained. BELLE e+e- data are shown to be compatible with our estimates based on the extracted Collins fragmentation functions. Predictions for A{sub UT}{sup sin({phi}{sub h}+{phi}{sub S})} asymmetries at JLab and COMPASS operating on a proton target are given.

  11. Measurements of the Decay KL→e+e-μ+μ-

    NASA Astrophysics Data System (ADS)

    Alavi-Harati, A.; Alexopoulos, T.; Arenton, M.; Arisaka, K.; Barbosa, R. F.; Barker, A. R.; Barrio, M.; Bellantoni, L.; Bellavance, A.; Blucher, E.; Bock, G. J.; Bown, C.; Bright, S.; Cheu, E.; Coleman, R.; Corcoran, M. D.; Cox, B.; Erwin, A. R.; Escobar, C. O.; Ford, R.; Glazov, A.; Golossanov, A.; Gouffon, P.; Graham, J.; Hamm, J.; Hanagaki, K.; Hsiung, Y. B.; Huang, H.; Jejer, V.; Jensen, D. A.; Kessler, R.; Kobrak, H. G.; Kotera, K.; Ladue, J.; Lai, N.; Ledovskoy, A.; McBride, P. L.; Monnier, E.; Nelson, K. S.; Nguyen, H.; Prasad, V.; Qi, X. R.; Quinn, B.; Ramberg, E. J.; Ray, R. E.; Santos, E.; Senyo, K.; Shanahan, P.; Shields, J.; Slater, W.; Solomey, N.; Swallow, E. C.; Taegar, S. A.; Tesarek, R. J.; Toale, P. A.; Tripathi, A.; Tschirhart, R.; Wah, Y. W.; Wang, J.; White, H. B.; Whitmore, J.; Wilking, M.; Winstein, B.; Winston, R.; Worcester, E. T.; Yamanaka, T.; Zukanovich, R. F.

    2003-04-01

    The KTeV experiment at Fermilab has isolated a total of 132events from the rare decay KL→e+e-μ+μ- , with an estimated background of 0.8events. The branching ratio of this mode is determined to be [2.69±0.24(stat)±0.12(syst)]×10-9, with a radiative cutoff of M2eeμμ /M2K>0.95. The first measurement using this mode of the parameter α from the D’Ambrosio-Isidori-Portolès (DIP) model of the KLγ*γ* vertex yields a result of -1.59±0.37, consistent with values obtained from other decay modes. Because of the limited statistics, no sensitivity is found to the DIP parameter β. We use this decay mode to set limits on CP and lepton violation.

  12. Measurements of the Decay KL-->e+ e- mu+ mu-.

    PubMed

    Alavi-Harati, A; Alexopoulos, T; Arenton, M; Arisaka, K; Barbosa, R F; Barker, A R; Barrio, M; Bellantoni, L; Bellavance, A; Blucher, E; Bock, G J; Bown, C; Bright, S; Cheu, E; Coleman, R; Corcoran, M D; Cox, B; Erwin, A R; Escobar, C O; Ford, R; Glazov, A; Golossanov, A; Gouffon, P; Graham, J; Hamm, J; Hanagaki, K; Hsiung, Y B; Huang, H; Jejer, V; Jensen, D A; Kessler, R; Kobrak, H G E; Kotera, K; LaDue, J; Lai, N; Ledovskoy, A; McBride, P L; Monnier, E; Nelson, K S; Nguyen, H; Prasad, V; Qi, X R; Quinn, B; Ramberg, E J; Ray, R E; Santos, E; Senyo, K; Shanahan, P; Shields, J; Slater, W; Solomey, N; Swallow, E C; Taegar, S A; Tesarek, R J; Toale, P A; Tripathi, A; Tschirhart, R; Wah, Y W; Wang, J; White, H B; Whitmore, J; Wilking, M; Winstein, B; Winston, R; Worcester, E T; Yamanaka, T; Zukanovich, R F

    2003-04-11

    The KTeV experiment at Fermilab has isolated a total of 132 events from the rare decay K(L)-->e+ e- mu+ mu-, with an estimated background of 0.8 events. The branching ratio of this mode is determined to be [2.69+/-0.24(stat)+/-0.12(syst)]x10(-9), with a radiative cutoff of M(2)(ee mu mu)/M(2)(K)>0.95. The first measurement using this mode of the parameter alpha from the D'Ambrosio-Isidori-Portolès (DIP) model of the K(L)gamma*gamma* vertex yields a result of -1.59+/-0.37, consistent with values obtained from other decay modes. Because of the limited statistics, no sensitivity is found to the DIP parameter beta. We use this decay mode to set limits on CP and lepton violation.

  13. The structure and shape of exotic nuclei beyond the proton drip-line

    SciTech Connect

    Ferreira, L. S.; Arumugam, P.; Maglione, E.

    2008-11-11

    Proton emission from deformed nuclei with triaxial symmetry is discussed within the non-adiabatic quasi-particle approach. As an example, we consider decay from {sup 161}Re, where we were able to reproduce the experimental half-life with a noticeable {gamma} deformation.

  14. Haglund's Deformity

    MedlinePlus

    ... deformity is often called “pump bump” because the rigid backs of pump-style shoes can create pressure ... when walking. In fact, any shoes with a rigid back, such as ice skates, men’s dress shoes ...

  15. Contracture deformity

    MedlinePlus

    Deformity - contracture ... Contracture can be caused by any of the following: Brain and nervous system disorders, such as cerebral ... Follow your health care provider's instructions for treating contracture at home. Treatments may include: Doing exercises and ...

  16. Energetic Nuclei, Superdensity and Biomedicine

    ERIC Educational Resources Information Center

    Baldin, A. M.

    1977-01-01

    High-energy, relativistic nuclei were first observed in cosmic rays. Studing these nuclei has provided an opportunity for analyzing the composition of cosmic rays and for experimentally verifying principles governing the behavior of nuclear matter at high and super-high temperatures. Medical research using accelerated nuclei is suggested.…

  17. Energetic Nuclei, Superdensity and Biomedicine

    ERIC Educational Resources Information Center

    Baldin, A. M.

    1977-01-01

    High-energy, relativistic nuclei were first observed in cosmic rays. Studing these nuclei has provided an opportunity for analyzing the composition of cosmic rays and for experimentally verifying principles governing the behavior of nuclear matter at high and super-high temperatures. Medical research using accelerated nuclei is suggested.…

  18. Spinal deformity.

    PubMed

    Bunnell, W P

    1986-12-01

    Spinal deformity is a relatively common disorder, particularly in teenage girls. Early detection is possible by a simple, quick visual inspection that should be a standard part of the routine examination of all preteen and teenage patients. Follow-up observation will reveal those curvatures that are progressive and permit orthotic treatment to prevent further increase in the deformity. Spinal fusion offers correction and stabilization of more severe degrees of scoliosis.

  19. Alternating-parity collective states of yrast and nonyrast bands in lanthanide and actinide nuclei

    SciTech Connect

    Nadirbekov, M. S. Yuldasheva, G. A.; Denisov, V. Yu.

    2015-03-15

    Excited collective states of even-even nuclei featuring quadrupole and octupole deformations are studied within a nonadiabatic collective model with a Gaussian potential energy. Rotational states of the yrast band and vibrational-rotational states of nonyrast bands are considered in detail. The energies of alternating-parity excited states of the yrast band in the {sup 164}Er, {sup 220}Ra, and {sup 224}Th nuclei; the yrast and first nonyrast bands in the {sup 154}Sm and {sup 160}Gd nuclei; and the yrast, first nonyrast, and second nonyrast bands in the {sup 224}Ra and {sup 240}Pu nuclei are described well on the basis of the proposed model.

  20. Generation of high-energy neutron beam by fragmentation of relativistic heavy nuclei

    NASA Astrophysics Data System (ADS)

    Yurevich, Vladimir

    2016-09-01

    The phenomenon of multiple production of neutrons in reactions with heavy nuclei induced by high-energy protons and light nuclei is analyzed using a Moving Source Model. The Lorentz transformation of the obtained neutron distributions is used to study the neutron characteristics in the inverse kinematics where relativistic heavy nuclei bombard a light-mass target. The neutron beam generated at 0∘has a Gaussian shape with a maximum at the energy of the projectile nucleons and an energy resolution σE/E < 4% above 6 GeV.

  1. Nuclei and Fundamental Symmetries

    NASA Astrophysics Data System (ADS)

    Haxton, Wick

    2016-09-01

    Nuclei provide marvelous laboratories for testing fundamental interactions, often enhancing weak processes through accidental degeneracies among states, and providing selection rules that can be exploited to isolate selected interactions. I will give an overview of current work, including the use of parity violation to probe unknown aspects of the hadronic weak interaction; nuclear electric dipole moment searches that may shed light on new sources of CP violation; and tests of lepton number violation made possible by the fact that many nuclei can only decay by rare second-order weak interactions. I will point to opportunities in both theory and experiment to advance the field. Based upon work supported in part by the US Department of Energy, Office of Science, Office of Nuclear Physics and SciDAC under Awards DE-SC00046548 (Berkeley), DE-AC02-05CH11231 (LBNL), and KB0301052 (LBNL).

  2. Interplay between one-particle and collective degrees of freedom in nuclei

    NASA Astrophysics Data System (ADS)

    Hamamoto, Ikuko

    2016-02-01

    Some developments of nuclear-structure physics uniquely related to Copenhagen School are sketched based on theoretical considerations versus experimental findings and one-particle versus collective aspects. Based on my personal overview I pick up the following topics; (1) Study of vibration in terms of particle-vibration coupling; (2) one-particle motion in deformed and rotating potentials, and yrast spectroscopy in high-spin physics; (3) triaxial shape in nuclei: wobbling motion and chiral bands; (4) nuclear structure of drip line nuclei: in particular, shell-structure (or magic numbers) change and spherical or deformed halo phenomena; (5) shell structure in oblate deformation.

  3. Potential energy surfaces of superheavy nuclei

    SciTech Connect

    Bender, M.; Rutz, K.; Maruhn, J.A.; Greiner, W.; Reinhard, P.-G. Rutz, K.; Maruhn, J.A.; Greiner, W.

    1998-10-01

    We investigate the structure of the potential energy surfaces of the superheavy nuclei {sub 158}{sup 258}Fm{sub 100}, {sub 156}{sup 264}Hs{sub 108}, {sub 166}{sup 278}112, {sub 184}{sup 298}114, and {sub 172}{sup 292}120 within the framework of self-consistent nuclear models, i.e., the Skyrme-Hartree-Fock approach and the relativistic mean-field model. We compare results obtained with one representative parametrization of each model which is successful in describing superheavy nuclei. We find systematic changes as compared to the potential energy surfaces of heavy nuclei in the uranium region: there is no sufficiently stable fission isomer any more, the importance of triaxial configurations to lower the first barrier fades away, and asymmetric fission paths compete down to rather small deformation. Comparing the two models, it turns out that the relativistic mean-field model gives generally smaller fission barriers. {copyright} {ital 1998} {ital The American Physical Society}

  4. The clinical utility of fetal cell sorting to determine prenatally fetal E/e or e/e Rh genotype from peripheral maternal blood.

    PubMed

    Geifman-Holtzman, O; Makhlouf, F; Kaufman, L; Gonchoroff, N J; Holtzman, E J

    2000-08-01

    This study was undertaken to determine the fetal E/e or e/e Rh genotype prenatally from peripheral maternal blood by examining sorted fetal cells from alloimmunized and nonalloimmunized pregnancies. Eighteen maternal peripheral venous blood samples were obtained before amniocentesis from 15 pregnant women who were homozygous for the e allele. Five were not alloimmunized and 10 were alloimmunized. The mononuclear cell layer was isolated from the maternal blood and enriched for fetal nucleated red blood cells by flow cytometry with monoclonal antibodies to CD36 or CD71 and to glycophorin A. Eight samples were treated with CD45 monoclonal antibody-coated magnetic beads before they were sorted to deplete the maternal sample of leukocytes (CD45(+) cells). We defined the positive fetal cell fractions as the monoclonal antibody positive-sorted cells derived from the maternal samples. These included sorted cells that were CD36(+)/glycophorin A(+), CD71(+)/glycophorin A(+) and CD45(-) cells that were sorted to become CD45(-)/CD36(+)/glycophorin A(+) or CD45(-)/CD71(+)/glycophorin A(+). The negative fractions were the cells that were negative for either CD36/glycophorin A or CD71/glycophorin A or were the CD45(+) cells. Deoxyribonucleic acid was isolated from all fractions and amplified by polymerase chain reaction with allele-specific primers for the E or e Rh genes. Gel electrophoresis was performed to detect fetal E/e or e/e Rh genotype. The fetal E/e or e/e Rh genotype was confirmed by serologic and deoxyribonucleic acid testing. The accuracy of E/e or e/e Rh genotype determination from the positive cell fractions was compared with that of E/e or e/e Rh genotype determination from the negative fractions. Fetal E/e or e/e Rh genotype was determined correctly in 17 of 18 of the fetal cell enriched positive fractions (94%). Fetal E/e or e/e Rh genotype was determined correctly in 11 of 14 of the maternal samples in the negative unselected cell fractions (79%). Fetal E/e or

  5. Nuclear dynamical deformation induced hetero- and euchromatin positioning

    NASA Astrophysics Data System (ADS)

    Awazu, Akinori

    2015-09-01

    We studied the role of active deformation dynamics in cell nuclei in chromatin positioning. Model chains containing two types of regions, with high (euchromatic) or low (heterochromatic) mobility, were confined in a pulsating container simulating a nucleus showing dynamic deformations. Brownian dynamic simulations show that the positioning of low mobility regions changes from sites near the periphery to the center if the affinity between these regions and the container periphery disappears. The former and latter positionings are similar to the "conventional" and "inverted" chromatin positionings in nuclei of normal differentiated cells and cells lacking Lamin-related proteins. Additionally, nuclear dynamical deformation played essential roles in "inverted" chromatin positioning.

  6. Fusion-fission of superheavy nuclei and clustering phenomena

    NASA Astrophysics Data System (ADS)

    Itkis, M. G.; Itkis, I. M.; Knyazheva, G. N.; Kozulin, E. M.

    2017-06-01

    Results of the study of mass-energy distributions of binary fragments for a wide range of nuclei with Z = 82-122 produced in reactions with heavy ions at energies close and below the Coulomb barrier are reported. The role of the shell effects, the influence of the entrance channel asymmetry and the deformations of colliding nuclei on the mechanism of the fusion-fission and quasifission processes are discussed. The observed peculiarities of the mass and energy distributions of reaction fragments are determined by the shell structure of the formed fragments.

  7. Search for JPC=1-+ exotic state in e +e- annihilation

    NASA Astrophysics Data System (ADS)

    Wang, Qian

    2014-06-01

    The P-wave and S-wave heavy-light mesons and their charge conjugates, i.e., D1(2420)D¯+c .c., D1(2420)D¯*+c .c., and D2(2460)D¯*+c .c., can couple to states with vector quantum number JPC=1-- and exotic quantum number JPC=1-+ in a relative S wave. Near threshold, the heavy-light meson pair may form hadronic molecules due to the strong S-wave coupling, and the mysterious vector state Y(4260) could be such a state of the D1(2420)D¯+c .c. molecule. This implies the possible existence of its conjugate partner made of the same heavy-light mesons but with exotic quantum number JPC=1-+. We evaluate the production rate of such exotic hadronic molecules and propose a direct experimental search for them in e +e- annihilation. Confirmation of such exotic states in experiment will certainly deepen our insights into strong QCD and the arrangement of multiquark degrees of freedom.

  8. Lower bound on e+e- decay of massive neutrinos

    NASA Technical Reports Server (NTRS)

    Cowsik, R.; Schramm, D. N.; Hoflicn, P

    1988-01-01

    Astronomical observations of SN1987A, such as the light curve, spectral intensities of lines, the X-ray emissions, etc., constrain the lifetime for the decay of a heavy neutrino 1 MeV less than or equivalent to m sub nu H less than or equal to 50 MeV through nu sub H yields nu sub 1+e(+)+e(-) exceeds 4 x 10 to the 15th exp(-m sub nuH/5MeV) seconds. Otherwise. resulting ionization energy deposits and stronger X-ray emission would have been observed. This coupled with traditional cosmological considerations argues that the lifetime of tau-neutrinos probably exceeds the age of the universe. This in turn would imply the standard cosmological mass bound does apply to nu sub tau, namely m sub nu sub tau less than or equivalent to 100 h squared eV (where h is the Hubble constant in units of 100 km/sec/mpc). The only significant loophole for these latter arguments would be if nu sub tau primarily decays rapidly into particles having very weak interactions.

  9. Observation of ψ (3686 )→e+e-χc J and χc J→e+e-J /ψ

    NASA Astrophysics Data System (ADS)

    Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Baldini Ferroli, R.; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; de Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Dou, Z. L.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Farinelli, R.; Fava, L.; Fedorov, O.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. L.; Gao, X. Y.; Gao, Y.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, L.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, R. P.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S.; Hao, X. Q.; Harris, F. A.; He, K. L.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang, X. Z.; Huang, Y.; Huang, Z. L.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. W.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kiese, P.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kupsc, A.; Kühn, W.; Lange, J. S.; Lara, M.; Larin, P.; Leng, C.; Li, C.; Li, Cheng; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, H. J.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, Q. Y.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, Y. B.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B.; Liu, B. J.; Liu, C. X.; Liu, D.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, M. M.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Ma, Y. M.; Maas, F. E.; Maggiora, M.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales Morales, C.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pan, Y.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Prasad, V.; Qi, H. R.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ripka, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Sarantsev, A.; Savrié, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Shi, M.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. H.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, S. G.; Wang, W.; Wang, W. P.; Wang, X. F.; Wang, Y.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, L. J.; Wu, Z.; Xia, L.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, J. J.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zeng, Z.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. Q.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. N.; Zhang, Y. T.; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zotti, L.; Zou, B. S.; Zou, J. H.; Besiii Collaboration

    2017-06-01

    Using 4.479 ×1 08 ψ (3686 ) events collected with the BESIII detector, we search for the decays ψ (3686 )→e+e-χc J and χc J→e+e-J /ψ , where J =0 , 1, 2. The decays ψ (3686 )→e+e-χc J and χc J→e+e-J /ψ are observed for the first time. The measured branching fractions are B (ψ (3686 )→e+e-χc J)=(11.7 ±2.5 ±1.0 )×10-4 , (8.6 ±0.3 ±0.6 )×10-4, (6.9 ±0.5 ±0.6 )×10-4 for J =0 , 1, 2, and B (χc J→e+e-J /ψ )=(1.51 ±0.30 ±0.13 )×10-4 , (3.73 ±0.09 ±0.25 )×10-3, (2.48 ±0.08 ±0.16 )×10-3 for J =0 , 1, 2, respectively. The ratios of the branching fractions B (ψ (3686 )→e+e-χc J)/B (ψ (3686 )→γ χc J) and B (χc J→e+e-J /ψ )/B (χc J→γ J /ψ ) are also reported. Also, the α values of helicity angular distributions of the e+e- pair are determined for ψ (3686 )→e+e-χc 1 ,2 and χc 1 ,2→e+e-J /ψ .

  10. Observation of ψ(3686)→e^{+}e^{-}χ_{cJ} and χ_{cJ}→e^{+}e^{-}J/ψ.

    PubMed

    Ablikim, M; Achasov, M N; Ai, X C; Albayrak, O; Albrecht, M; Ambrose, D J; Amoroso, A; An, F F; An, Q; Bai, J Z; Baldini Ferroli, R; Ban, Y; Bennett, D W; Bennett, J V; Bertani, M; Bettoni, D; Bian, J M; Bianchi, F; Boger, E; Boyko, I; Briere, R A; Cai, H; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, H Y; Chen, J C; Chen, M L; Chen, S; Chen, S J; Chen, X; Chen, X R; Chen, Y B; Cheng, H P; Chu, X K; Cibinetto, G; Dai, H L; Dai, J P; Dbeyssi, A; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; De Mori, F; Ding, Y; Dong, C; Dong, J; Dong, L Y; Dong, M Y; Dou, Z L; Du, S X; Duan, P F; Fan, J Z; Fang, J; Fang, S S; Fang, X; Fang, Y; Farinelli, R; Fava, L; Fedorov, O; Feldbauer, F; Felici, G; Feng, C Q; Fioravanti, E; Fritsch, M; Fu, C D; Gao, Q; Gao, X L; Gao, X Y; Gao, Y; Gao, Z; Garzia, I; Goetzen, K; Gong, L; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, R P; Guo, Y; Guo, Y P; Haddadi, Z; Hafner, A; Han, S; Hao, X Q; Harris, F A; He, K L; Held, T; Heng, Y K; Hou, Z L; Hu, C; Hu, H M; Hu, J F; Hu, T; Hu, Y; Huang, G S; Huang, J S; Huang, X T; Huang, X Z; Huang, Y; Huang, Z L; Hussain, T; Ji, Q; Ji, Q P; Ji, X B; Ji, X L; Jiang, L W; Jiang, X S; Jiang, X Y; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Johansson, T; Julin, A; Kalantar-Nayestanaki, N; Kang, X L; Kang, X S; Kavatsyuk, M; Ke, B C; Kiese, P; Kliemt, R; Kloss, B; Kolcu, O B; Kopf, B; Kornicer, M; Kupsc, A; Kühn, W; Lange, J S; Lara, M; Larin, P; Leng, C; Li, C; Li, Cheng; Li, D M; Li, F; Li, F Y; Li, G; Li, H B; Li, H J; Li, J C; Li, Jin; Li, K; Li, K; Li, Lei; Li, P R; Li, Q Y; Li, T; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, Y B; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Lin, D X; Liu, B; Liu, B J; Liu, C X; Liu, D; Liu, F H; Liu, Fang; Liu, Feng; Liu, H B; Liu, H H; Liu, H H; Liu, H M; Liu, J; Liu, J B; Liu, J P; Liu, J Y; Liu, K; Liu, K Y; Liu, L D; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, Y B; Liu, Z A; Liu, Zhiqing; Loehner, H; Lou, X C; Lu, H J; Lu, J G; Lu, Y; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lyu, X R; Ma, F C; Ma, H L; Ma, L L; Ma, M M; Ma, Q M; Ma, T; Ma, X N; Ma, X Y; Ma, Y M; Maas, F E; Maggiora, M; Mao, Y J; Mao, Z P; Marcello, S; Messchendorp, J G; Min, J; Mitchell, R E; Mo, X H; Mo, Y J; Morales Morales, C; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nerling, F; Nikolaev, I B; Ning, Z; Nisar, S; Niu, S L; Niu, X Y; Olsen, S L; Ouyang, Q; Pacetti, S; Pan, Y; Patteri, P; Pelizaeus, M; Peng, H P; Peters, K; Pettersson, J; Ping, J L; Ping, R G; Poling, R; Prasad, V; Qi, H R; Qi, M; Qian, S; Qiao, C F; Qin, L Q; Qin, N; Qin, X S; Qin, Z H; Qiu, J F; Rashid, K H; Redmer, C F; Ripka, M; Rong, G; Rosner, Ch; Ruan, X D; Sarantsev, A; Savrié, M; Schoenning, K; Schumann, S; Shan, W; Shao, M; Shen, C P; Shen, P X; Shen, X Y; Sheng, H Y; Shi, M; Song, W M; Song, X Y; Sosio, S; Spataro, S; Sun, G X; Sun, J F; Sun, S S; Sun, X H; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Tiemens, M; Ullrich, M; Uman, I; Varner, G S; Wang, B; Wang, B L; Wang, D; Wang, D Y; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, S G; Wang, W; Wang, W P; Wang, X F; Wang, Y; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z H; Wang, Z Y; Wang, Z Y; Weber, T; Wei, D H; Wei, J B; Weidenkaff, P; Wen, S P; Wiedner, U; Wolke, M; Wu, L H; Wu, L J; Wu, Z; Xia, L; Xia, L G; Xia, Y; Xiao, D; Xiao, H; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, J J; Xu, L; Xu, Q J; Xu, Q N; Xu, X P; Yan, L; Yan, W B; Yan, W C; Yan, Y H; Yang, H J; Yang, H X; Yang, L; Yang, Y X; Ye, M; Ye, M H; Yin, J H; Yu, B X; Yu, C X; Yu, J S; Yuan, C Z; Yuan, W L; Yuan, Y; Yuncu, A; Zafar, A A; Zallo, A; Zeng, Y; Zeng, Z; Zhang, B X; Zhang, B Y; Zhang, C; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J; Zhang, J J; Zhang, J L; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, K; Zhang, L; Zhang, S Q; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Y N; Zhang, Y T; Zhang, Yu; Zhang, Z H; Zhang, Z P; Zhang, Z Y; Zhao, G; Zhao, J W; Zhao, J Y; Zhao, J Z; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, Q W; Zhao, S J; Zhao, T C; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, W J; Zheng, Y H; Zhong, B; Zhou, L; Zhou, X; Zhou, X K; Zhou, X R; Zhou, X Y; Zhu, K; Zhu, K J; Zhu, S; Zhu, S H; Zhu, X L; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, J; Zotti, L; Zou, B S; Zou, J H

    2017-06-02

    Using 4.479×10^{8}  ψ(3686) events collected with the BESIII detector, we search for the decays ψ(3686)→e^{+}e^{-}χ_{cJ} and χ_{cJ}→e^{+}e^{-}J/ψ, where J=0, 1, 2. The decays ψ(3686)→e^{+}e^{-}χ_{cJ} and χ_{cJ}→e^{+}e^{-}J/ψ are observed for the first time. The measured branching fractions are B(ψ(3686)→e^{+}e^{-}χ_{cJ})=(11.7±2.5±1.0)×10^{-4}, (8.6±0.3±0.6)×10^{-4}, (6.9±0.5±0.6)×10^{-4} for J=0, 1, 2, and B(χ_{cJ}→e^{+}e^{-}J/ψ)=(1.51±0.30±0.13)×10^{-4}, (3.73±0.09±0.25)×10^{-3}, (2.48±0.08±0.16)×10^{-3} for J=0, 1, 2, respectively. The ratios of the branching fractions B(ψ(3686)→e^{+}e^{-}χ_{cJ})/B(ψ(3686)→γχ_{cJ}) and B(χ_{cJ}→e^{+}e^{-}J/ψ)/B(χ_{cJ}→γJ/ψ) are also reported. Also, the α values of helicity angular distributions of the e^{+}e^{-} pair are determined for ψ(3686)→e^{+}e^{-}χ_{c1,2} and χ_{c1,2}→e^{+}e^{-}J/ψ.

  11. Size-Invariant Detection of Cell Nuclei in Microscopy Images.

    PubMed

    Ram, Sundaresh; Rodriguez, Jeffrey J

    2016-07-01

    Accurate detection of individual cell nuclei in microscopy images is an essential and fundamental task for many biological studies. In particular, multivariate fluorescence microscopy is used to observe different aspects of cells in cultures. Manual detection of individual cell nuclei by visual inspection is time consuming, and prone to induce subjective bias. This makes automatic detection of cell nuclei essential for large-scale, objective studies of cell cultures. Blur, clutter, bleed-through, imaging noise and touching and partially overlapping nuclei with varying sizes and shapes make automated detection of individual cell nuclei a challenging task using image analysis. In this paper we propose a new automated method for fast and robust detection of individual cell nuclei based on their radial symmetric nature in fluorescence in-situ hybridization (FISH) images obtained via confocal microscopy. The main contributions are two-fold. 1) This work presents a more accurate cell nucleus detection system using the fast radial symmetry transform (FRST). 2) The proposed cell nucleus detection system is robust against most occlusions and variations in size and moderate shape deformations. We evaluate the performance of the proposed algorithm using precision/recall rates, Fβ-score and root-mean-squared distance (RMSD) and show that our algorithm provides improved detection accuracy compared to existing algorithms.

  12. Quaternary deformation

    SciTech Connect

    Brown, R.D. Jr.

    1990-01-01

    Displaced or deformed rock units and landforms record the past 2 m.y. of faulting, folding, uplift, and subsidence in California. Properly interpreted, such evidence provides a quantitative basis for predicting future earthquake activity and for relating many diverse structures and landforms to the 5 cm/yr of horizontal motion at the boundary between the North American and Pacific plates. Modern techniques of geologic dating and expanded research on earthquake hazards have greatly improved our knowledge of the San Andreas fault system. Much of this new knowledge has been gained since 1965, and that part which concerns crustal deformation during the past 2 m.y. is briefly summarized here.

  13. Theoretical Interpretation of Pass 8 Fermi -LAT e + + e - Data

    DOE PAGES

    Di Mauro, M.; Manconi, S.; Vittino, A.; ...

    2017-08-17

    The flux of positrons and electrons (e + + e -) has been measured by the Fermi Large Area Telescope (LAT) in the energy range between 7 GeV and 2 TeV. Here, we discuss a number of interpretations of Pass 8 Fermi-LAT e sup>+ + e - spectrum, combining electron and positron emission from supernova remnants (SNRs) and pulsar wind nebulae (PWNe), or produced by the collision of cosmic rays (CRs) with the interstellar medium. We also found that the Fermi-LAT spectrum is compatible with the sum of electrons from a smooth SNR population, positrons from cataloged PWNe, and amore » secondary component. If we include in our analysis constraints from the AMS-02 positron spectrum, we obtain a slightly worse fit to the e sup>+ + e - Fermi-LAT spectrum, depending on the propagation model. As an additional scenario, we replace the smooth SNR component within 0.7 kpc with the individual sources found in Green's catalog of Galactic SNRs. We find that separate consideration of far and near sources helps to reproduce the e sup>+ + e - Fermi-LAT spectrum. However, we show that the fit degrades when the radio constraints on the positron emission from Vela SNR (which is the main contributor at high energies) are taken into account. We find that a break in the power-law injection spectrum at about 100 GeV can also reproduce the measured e sup>+ + e - spectrum and, among the CR propagation models that we consider, no reasonable break of the power-law dependence of the diffusion coefficient can modify the electron flux enough to reproduce the observed shape.« less

  14. Properties of Cometary Nuclei

    NASA Technical Reports Server (NTRS)

    Rahe, J.; Vanysek, V.; Weissman, P. R.

    1994-01-01

    Active long- and short-period comets contribute about 20 to 30 % of the major impactors on the Earth. Cometary nuclei are irregular bodies, typically a few to ten kilometers in diameter, with masses in the range 10(sup 15) to 10(sup 18) g. The nuclei are composed of an intimate mixture of volatile ices, mostly water ice and hydrocarbon and silicate grains. The composition is the closest to solar composition of any known bodies in the solar system. The nuclei appear to be weakly bonded agglomerations of smaller icy planetesimals, and material strengths estimated from observed tidal disruption events are fairly low, typically 10(sup 2) to 10(sup 4) N m(sup -2). Density estimates range between 0.2 and 1.2 g cm(sup -3) but are very poorly determined, if at all. As comets age they develop nonvolitile crusts on their surfaces which eventually render them inactive, similar in appearance to carbonaceous asteroids. However, dormant comets may continue to show sporadic activity and outbursts for some time before they become truly extinct. The source of the long-period comets is the Oort cloud, a vast spherical cloud of perhaps 10(sup 12) to 10(sup 13) comets surrounding the solar system and extending to interstellar distances. The likely source for short-period comets is the Kuiper belt. a ring of perhaps 10(sup 8) to 10(sup 10) remnant icy planetesimals beyond the orbit of Neptune, though some short-period comets may also be long-period comets from the Oort cloud which have been perturbed into short-period orbits.

  15. Skyrmions and Nuclei

    NASA Astrophysics Data System (ADS)

    Battye, R. A.; Manton, N. S.; Sutcliffe, P. M.

    We review recent work on the modelling of atomic nuclei as quantised Skyrmions, using Skyrme's original model with pion fields only. Skyrmions are topological soliton solutions, whose conserved topological charge B is identified with the baryon number of a nucleus. Apart from an energy and length scale, the Skyrme model has just one dimensionless parameter m, proportional to the pion mass. It has been found that a good fit to experimental nuclear data requires m to be of order 1. The Skyrmions for B up to 7 have been known for some time, and are qualitatively insensitive to whether m is zero or of order 1. However, for baryon numbers B = 8 and above, the Skyrmions have quite a compact structure for m of order 1, rather than the hollow polyhedral structure found when m = 0. One finds for baryon numbers which are multiples of four, that the Skyrmions are composed of B = 4 sub-units, as in the α-particle model of nuclei. The rational map ansatz gives a useful approximation to the Skyrmion solutions for all baryon numbers when m = 0. For m of order 1, it gives a good approximation for baryon numbers up to 7, and generalisations of this ansatz are helpful for higher baryon numbers. We briefly review the work from the 1980s and 90s on the semiclassical rigidbody quantisation of Skyrmions for B = 1, 2, 3 and 4. We then discuss more recent work extending this method to B = 6, 7, 8, 10 and 12. We determine the quantum states of the Skyrmions, finding their spins, isospins and parities, and compare with the experimental data on the ground and excited states of nuclei up to mass number 12.

  16. Total photoabsorption in nuclei

    SciTech Connect

    Bianchi, N.

    1992-06-01

    The Frascati-Genova collaboration proposes to measure the total photonuclear cross section on a wide range of nuclei between 500 MeV and 2 GeV, to obtain informations on the interaction of baryon resonances with nucleons and on the onset of the shadowing effect. The experiment could be performed in the Hall B as soon as the tagging facility will be ready and before the end of the installation of the CLAS spectrometer. The requirements for the photon beam, like maximum energy, intensity and beam definition, are not so strong so that the experiment would also be a good first test of the tagged photon facility.

  17. Lattice QCD for nuclei

    NASA Astrophysics Data System (ADS)

    Beane, Silas

    2016-09-01

    Over the last several decades, theoretical nuclear physics has been evolving from a very-successful phenomenology of the properties of nuclei, to a first-principles derivation of the properties of visible matter in the Universe from the known underlying theories of Quantum Chromodynamics (QCD) and Electrodynamics. Many nuclear properties have now been calculated using lattice QCD, a method for treating QCD numerically with large computers. In this talk, some of the most recent results in this frontier area of nuclear theory will be reviewed.

  18. Measurement of initial-state-final-state radiation interference in the processes e+e-→μ+μ-γ and e+e-→π+π-γ

    NASA Astrophysics Data System (ADS)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lee, M. J.; Lynch, G.; Koch, H.; Schroeder, T.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Lankford, A. J.; Dey, B.; Gary, J. W.; Long, O.; Franco Sevilla, M.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Lockman, W. S.; Panduro Vazquez, W.; Schumm, B. A.; Seiden, A.; Chao, D. S.; Cheng, C. H.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Kim, J.; Miyashita, T. S.; Ongmongkolkul, P.; Porter, F. C.; Röhrken, M.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Pushpawela, B. G.; Sokoloff, M. D.; Sun, L.; Ford, W. T.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Bernard, D.; Verderi, M.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Piemontese, L.; Santoro, V.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Martellotti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Zallo, A.; Contri, R.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Bhuyan, B.; Prasad, V.; Adametz, A.; Uwer, U.; Lacker, H. M.; Mallik, U.; Chen, C.; Cochran, J.; Prell, S.; Ahmed, H.; Gritsan, A. V.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Stocchi, A.; Wang, L. L.; Wormser, G.; Lange, D. J.; Wright, D. M.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; di Lodovico, F.; Sacco, R.; Cowan, G.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Schubert, K. R.; Barlow, R. J.; Lafferty, G. D.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Cowan, R.; Cheaib, R.; Patel, P. M.; Robertson, S. H.; Neri, N.; Palombo, F.; Cremaldi, L.; Godang, R.; Summers, D. J.; Simard, M.; Taras, P.; de Nardo, G.; Onorato, G.; Sciacca, C.; Raven, G.; Jessop, C. P.; Losecco, J. M.; Honscheid, K.; Kass, R.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Biasini, M.; Manoni, E.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Chrzaszcz, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Rama, M.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Olsen, J.; Smith, A. J. S.; Anulli, F.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Pilloni, A.; Piredda, G.; Bünger, C.; Dittrich, S.; Grünberg, O.; Hess, M.; Leddig, T.; Voß, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Vasseur, G.; Aston, D.; Bard, D. J.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Fulsom, B. G.; Graham, M. T.; Hast, C.; Innes, W. R.; Kim, P.; Leith, D. W. G. S.; Luitz, S.; Luth, V.; Macfarlane, D. B.; Muller, D. R.; Neal, H.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'Vra, J.; Wisniewski, W. J.; Wulsin, H. W.; Purohit, M. V.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Puccio, E. M. T.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Spanier, S. M.; Ritchie, J. L.; Schwitters, R. F.; Izen, J. M.; Lou, X. C.; Bianchi, F.; de Mori, F.; Filippi, A.; Gamba, D.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.; Oyanguren, A.; Albert, J.; Banerjee, Sw.; Beaulieu, A.; Bernlochner, F. U.; Choi, H. H. F.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Lueck, T.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.; Wu, S. L.; Babar Collaboration

    2015-10-01

    Charge asymmetry in the processes e+e- →μ+μ-γ and e+e- →π+π-γ is measured using 232 fb-1 of data collected with the BABAR detector at e+e- center-of-mass energies near 10.58 GeV. An observable is introduced and shown to be very robust against detector asymmetries while keeping a large sensitivity to the physical charge asymmetry that results from the interference between initial- and final-state radiation (FSR). The asymmetry is determined as a function of the invariant mass of the final-state tracks from production threshold to a few GeV /c2 . It is compared to the expectation from QED for e+e- →μ+μ-γ , and from theoretical models for e+e- →π+π-γ . A clear interference pattern is observed in e+e- →π+π-γ , particularly in the vicinity of the f2(1270 ) resonance. The inferred rate of lowest-order FSR production is consistent with the QED expectation for e+e- →μ+μ-γ , and is negligibly small for e+e- →π+π-γ .

  19. The ^2H(e,e'p)n Reaction at High Four-Momentum Transfer

    SciTech Connect

    Hassan Ibrahim

    2006-12-31

    This dissertation presents the highest four-momentum transfer, Q^2,quasielastic (x_Bj = 1) results from Experiment E01-020 which systematically explored the 2He(e,e'p)n reaction ("Electro-disintegration" of the deuteron) at three different four-momentum transfers, Q^2 = 0.8, 2.1, and 3.5 GeV^2 and missing momenta, P_miss = 0, 100, 200, 300, 400, and 500 GeV including separations of the longitudinal-transverse interference response function, R_LT, and extractoin of the longitudinal-transverse asymmetry, A_LT. This systematic approach will help to understand the reaction mechanism and the deuteron structure down to the short range part of the nucleon-nucleon interaction which is one of the fundamental missions of nuclear physics. By studying the very short distance structure of the deuteron, one may also determine whether or to what extent the description of nuclei in terms of nucleon/meson degrees of freedom must be supplemented by inclusion of explicit quark effects. The unique combination of energy, current, duty factor, and control of systematics for Hall A at Jefferson Lab made Jefferson Lab the only facility in the world where these systematic studies of the deuteron can be undertaken. This is especially true when we want to understand the short range structure of the deuteron where high energies and high luminosity/duty factor are needed. All these features of Jefferson Lab allow us to examine large missing momenta (short range scales) at kinematics where the effects of final state interactions (FSI), meson exchange currents (MEC), and isobar currents (IC) are minimal, making the extraction of the deuteron structure less model-dependent. Jefferson Lab also provides the kinematical flexibility to perform the separation of R_LT over a broad range of missing momenta and momentum transfers. Experiment E01-020 use the standard Hall A equipment in coincidence configuration in addition to the cryogenic target system. The low and middle Q^2 kinematics were completed

  20. D mesic nuclei

    NASA Astrophysics Data System (ADS)

    García-Recio, C.; Nieves, J.; Tolos, L.

    2010-06-01

    The energies and widths of several D0 meson bound states for different nuclei are obtained using a D-meson selfenergy in the nuclear medium, which is evaluated in a selfconsistent manner using techniques of unitarized coupled-channel theory. The kernel of the meson-baryon interaction is based on a model that treats heavy pseudoscalar and heavy vector mesons on equal footing, as required by heavy quark symmetry. We find D0 bound states in all studied nuclei, from 12C up to 208Pb. The inclusion of vector mesons is the keystone for obtaining an attractive D-nucleus interaction that leads to the existence of D0-nucleus bound states, as compared to previous studies based on SU(4) flavor symmetry. In some cases, the half widths are smaller than the separation of the levels, what makes possible their experimental observation by means of a nuclear reaction. This can be of particular interest for the future P¯ANDA@FAIR physics program. We also find a D+ bound state in 12C, but it is too broad and will have a significant overlap with the energies of the continuum.

  1. Collective modes in light nuclei from first principles.

    PubMed

    Dytrych, T; Launey, K D; Draayer, J P; Maris, P; Vary, J P; Saule, E; Catalyurek, U; Sosonkina, M; Langr, D; Caprio, M A

    2013-12-20

    Results for ab initio no-core shell model calculations in a symmetry-adapted SU(3)-based coupling scheme demonstrate that collective modes in light nuclei emerge from first principles. The low-lying states of 6Li, 8Be, and 6He are shown to exhibit orderly patterns that favor spatial configurations with strong quadrupole deformation and complementary low intrinsic spin values, a picture that is consistent with the nuclear symplectic model. The results also suggest a pragmatic path forward to accommodate deformation-driven collective features in ab initio analyses when they dominate the nuclear landscape.

  2. Heavy and Superheavy Atomic Nuclei

    NASA Astrophysics Data System (ADS)

    Sobiczewski, Adam

    2008-10-01

    The appearance and development of the concept of super-heavy atomic nuclei are described. The concept appeared during the studies of the limits of the nuclear chart and of the periodic table of the chemical elements. The article concentrates on theoretical studies of the properties of heaviest nuclei. Results of these studies are illustrated and discussed. Prospects for a nearest future of the research of heaviest nuclei are outlined.

  3. Studies of the Shapes of Heavy Nuclei at ISOLDE

    NASA Astrophysics Data System (ADS)

    Butler, Peter A.

    For certain combinations of protons and neutrons there is a theoretical expectation that the shape of nuclei can assume octupole deformation, which would give rise to reflection asymmetry or a "pear-shape" in the intrinsic frame, either dynamically (octupole vibrations) or statically (permanent octupole deformation). In this talk I will briefly review the historic evidence for reflection asymmetry in nuclei and describe how recent experiments carried out at REX-ISOLDE have constrained nuclear theory and how they contribute to tests of extensions of the Standard Model. I will also discuss future prospects for measuring nuclear shapes from Coulomb Excitation: experiments are being planned that will exploit beams from HIE-ISOLDE that are cooled in the TSR storage ring and injected into a solenoidal spectrometer similar to the HELIOS device developed at the Argonne National Laboratory.

  4. Triaxial shape fluctuations and quasiparticle excitations in heavy nuclei

    NASA Astrophysics Data System (ADS)

    Chen, Fang-Qi; Egido, J. Luis

    2017-02-01

    The deformation parameters (β ,γ ) together with two-quasiparticle excitations are taken into account, for the first time, as coordinates within a symmetry conserving (angular momentum and particle number) generator coordinate method. The simultaneous consideration of collective as well as single-particle degrees of freedom allows us to describe soft and rigid nuclei as well as the transition region in between. We apply the new theory to the study of the spectra and transition probabilities of the Er-172156 isotopes with a pairing-plus-quadrupole residual interaction. Good agreement with the experimental results is obtained for most of the observables studied and with the same quality for the very soft and the strongly deformed nuclei.

  5. α-decay chains from 293,294117 superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Santhosh, K. P.; Priyanka, B.; Unnikrishnan, M. S.

    2012-03-01

    The phenomenon of α decay for 293,294117 superheavy nuclei is investigated within the Coulomb and proximity potential model for deformed nuclei (CPPMDN), in order to emphasize the recent experimental works on the element. The computed α-decay half-lives are in good agreement with the experimental results. It is clear that the values calculated using our formalisms match well with the values computed using the Viola-Seborg systematic, and with the values reported by the generalized density dependent cluster model. The α-decay calculations have also been performed for the decay chains of 293,294117 nuclei keeping the parents and daughter in spherical nuclear shape. These comparative studies ensure the validity of the CPPMDN.

  6. Exotic nuclei in astrophysics

    NASA Astrophysics Data System (ADS)

    Penionzhkevich, Yu. E.

    2012-07-01

    Recently the academic community has marked several anniversaries connected with discoveries that played a significant role in the development of astrophysical investigations. The year 2009 was proclaimed by the United Nations the International Year of Astronomy. This was associated with the 400th anniversary of Galileo Galilei's discovery of the optical telescope, which marked the beginning of regular research in the field of astronomy. An important contribution to not only the development of physics of the microcosm, but also to the understanding of processes occurring in the Universe, was the discovery of the atomic nucleus made by E. Rutherford 100 years ago. Since then the investigations in the fields of physics of particles and atomic nuclei have helped to understand many processes in the microcosm. Exactly 80 years ago, K. Yanski used a radio-telescope in order to receive the radiation from cosmic objects for the first time, and at the present time this research area of physics is the most efficient method for studying the properties of the Universe. Finally, the April 12, 1961 (50 years ago) launching of the first sputnik into space with a human being onboard, the Russian cosmonaut Yuri Gagarin, marked the beginning of exploration of the Universe with the direct participation of man. All these achievements considerably extended our ideas about the Universe. This work is an attempt to present some problems on the evolution of the Universe: the nucleosynthesis and cosmochronology from the standpoint of physics of particles and nuclei, in particular with the use of the latest results, obtained by means of radioactive nuclear beams. The comparison is made between the processes taking place in the Universe and the mechanisms of formation and decay of nuclei, as well as of their interaction at different energies. Examples are given to show the capabilities of nuclear-physics methods for studying cosmic objects and properties of the Universe. The results of

  7. Nucleomorphs: enslaved algal nuclei.

    PubMed

    Cavalier-Smith, T

    2002-12-01

    Nucleomorphs of cryptomonad and chlorarachnean algae are the relict, miniaturised nuclei of formerly independent red and green algae enslaved by separate eukaryote hosts over 500 million years ago. The complete 551 kb genome sequence of a cryptomonad nucleomorph confirms that cryptomonads are eukaryote-eukaryote chimeras and greatly illuminates the symbiogenetic event that created the kingdom Chromista and their alveolate protozoan sisters. Nucleomorph membranes may, like plasma membranes, be more enduring after secondary symbiogenesis than are their genomes. Partial sequences of chlorarachnean nucleomorphs indicate that genomic streamlining is limited by the mutational difficulty of removing useless introns. Nucleomorph miniaturisation emphasises that selection can dramatically reduce eukaryote genome size and eliminate most non-functional nuclear non-coding DNA. Given the differential scaling of nuclear and nucleomorph genomes with cell size, it follows that most non-coding nuclear DNA must have a bulk-sequence-independent function related to cell volume.

  8. Pulsars:. Gigantic Nuclei

    NASA Astrophysics Data System (ADS)

    Xu, Renxin

    What is the real nature of pulsars? This is essentially a question of the fundamental strong interaction between quarks at low-energy scale and hence of the non-perturbative quantum chromo-dynamics, the solution of which would certainly be meaningful for us to understand one of the seven millennium prize problems (i.e., "Yang-Mills Theory") named by the Clay Mathematical Institute. After a historical note, it is argued here that a pulsar is very similar to an extremely big nucleus, but is a little bit different from the gigantic nucleus speculated 80 years ago by L. Landau. The paper demonstrates the similarity between pulsars and gigantic nuclei from both points of view: the different manifestations of compact stars and the general behavior of the strong interaction.

  9. Crustal deformation

    NASA Astrophysics Data System (ADS)

    Larson, Kristine M.

    1995-07-01

    Geodetic measurements of crustal deformation provide direct tests of geophysical models which are used to describe the dynamics of the Earth. Although geodetic observations have been made throughout history, only in the last several hundred years have they been sufficiently precise for geophysical studies. In the 19th century, these techniques included leveling and triangulation. Approximately 25 years ago, trilateration measurements were initiated by the USGS (United States Geological Survey) to monitor active faults in the United States. Several years later, NASA (National Aeronautics and Space Administration) begin an effort to measure plate tectonic motions on a global scale, using space geodetic techniques, VLBI (Very Long Baseline Interferometry) and SLR (Satellite Laser Ranging). The period covered by this report to the IUGG, 1991-1994, was a transition period in the field of crustal deformation. Trilateration measurements (previously the backbone of measurements across plate boundaries in the western United States and Alaska) have been abandoned. This system was labor-intensive, involved highly trained crews to carry out the observations, and only measured the length between sites. In addition, NASA drastically cut the budgets for VLBI and SLR during this period. Fixed site VLBI systems are still operational, but mobile VLBI measurements in North America have ceased. SLR measurements continue on a global scale, but the remaining crustal deformation measurements are now being made with the Global Positioning System (GPS). Nonetheless, because of the time scales involved, older geodetic data (including leveling, triangulation, and trilateration) continue to be important for many geophysical studies.

  10. Compton scattering by nuclei

    NASA Astrophysics Data System (ADS)

    Hütt, M.-Th.; L'vov, A. I.; Milstein, A. I.; Schumacher, M.

    2000-01-01

    The concept of Compton scattering by even-even nuclei from giant-resonance to nucleon-resonance energies and the status of experimental and theoretical researches in this field are outlined. The description of Compton scattering by nuclei starts from different complementary approaches, namely from second-order S-matrix and from dispersion theories. Making use of these, it is possible to incorporate into the predicted nuclear scattering amplitudes all the information available from other channels, viz. photon-nucleon and photon-meson channels, and to efficiently make use of models of the nucleon, the nucleus and the nucleon-nucleon interaction. The total photoabsorption cross section constrains the nuclear scattering amplitude in the forward direction. The specific information obtained from Compton scattering therefore stems from the angular dependence of the nuclear scattering amplitude, providing detailed insight into the dynamics of the nuclear and nucleon degrees of freedom and into the interplay between them. Nuclear Compton scattering in the giant-resonance energy-region provides information on the dynamical properties of the in-medium mass of the nucleon. Most prominently, the electromagnetic polarizabilities of the nucleon in the nuclear medium can be extracted from nuclear Compton scattering data obtained in the quasi-deuteron energy-region. In our description of this latter process special emphasis is laid upon the exploration of many-body and two-body effects entering into the nuclear dynamics. Recent results are presented for two-body effects due to the mesonic seagull amplitude and due to the excitation of nucleon internal degrees of freedom accompanied by meson exchanges. Due to these studies the in-medium electromagnetic polarizabilities are by now well understood, whereas the understanding of nuclear Compton scattering in the Δ-resonance range is only at the beginning. Furthermore, phenomenological methods how to include retardation effects in the

  11. Favored configurations for four-quasiparticle K isomerism in the heaviest nuclei

    NASA Astrophysics Data System (ADS)

    Liu, H. L.; Walker, P. M.; Xu, F. R.

    2014-04-01

    Configuration-constrained potential-energy-surface calculations are performed including β6 deformation to investigate high-K isomeric states in nuclei around 254No and 270Ds, the heaviest nuclei where there have been some observations of two-quasiparticle isomers, while data for four-quasiparticle isomers are scarce. We predict the prevalent occurrence of four-quasiparticle isomeric states in these nuclei, together with their favored configurations. The most notable examples, among others, are Kπ=20+ states in 266,268Ds and 268,270Cn having very high K value, relatively low excitation energy, and well-deformed axially symmetric shape. The predicted isomeric states, with hindered spontaneous fission and α decay, could play a significant role in the future study of superheavy nuclei.

  12. Alpha decay and cluster decay of some neutron-rich actinide nuclei

    NASA Astrophysics Data System (ADS)

    Carmel Vigila Bai, G. M.; Agnes, R. Nithya

    2017-03-01

    Nuclei in the actinide region are good in exhibiting cluster radioactivity. In the present work, the half-lives of α-decay and heavy cluster emission from certain actinide nuclei have been calculated using cubic plus Yukawa plus exponential model (CYEM). Our model has a cubic potential for the overlapping region which is smoothly connected by a Yukawa plus exponential potential for the region after separation. The computed half-lives are compared with those of other theoretical models and are found to be in good agreement with each other. In this work, we have also studied the deformation effects on half-lives of cluster decay. These deformation effects lower the half-life values and it is also found that the neutron-rich parent nuclei slow down the cluster decay process. Geiger-Nuttal plots for various clusters are found to be linear and most of the emitted clusters are α-like nuclei.

  13. Effect of nuclear deformation on α-decay half-lives

    NASA Astrophysics Data System (ADS)

    Coban, A.; Bayrak, O.; Soylu, A.; Boztosun, I.

    2012-04-01

    We systematically investigate the influence of nuclear deformations on the α-decay half-lives of the deformed medium, heavy, and superheavy nuclei for 106⩽A⩽273 and 52⩽Z⩽110 from the ground state to ground state α transitions within the framework of the Wentzel--Kramers--Brillouin (WKB) method by considering the Bohr-Sommerfeld quantization condition. The deformed Wood-Saxon form in a phenomenological way and the deformed Coulomb potential in a special form have been used in order to take into account all deformation effects in the calculations and the preformation of the parent nuclei have also been regarded. Calculations have been conducted for the spherical nuclei in order to present clearly the effects of the deformations on the half-lives. We point out that all considerations have improved the results and very good agreement has been obtained with experimental data.

  14. Nonaxial-octupole effect in superheavy nuclei

    SciTech Connect

    Chen, Y.-S.; Sun, Yang; Gao Zaochun

    2008-06-15

    The triaxial-octupole Y{sub 32} correlation in atomic nuclei has long been expected to exist but experimental evidence has not been clear. We find, in order to explain the very low-lying 2{sup -} bands in the transfermium mass region, that this exotic effect may manifest itself in superheavy elements. Favorable conditions for producing triaxial-octupole correlations are shown to be present in the deformed single-particle spectrum, which is further supported by quantitative Reflection Asymmetric Shell Model calculations. It is predicted that the strong nonaxial-octupole effect may persist up to the element 108. Our result thus represents the first concrete example of spontaneous breaking of both axial and reflection symmetries in the heaviest nuclear systems.

  15. Shell energy and the level-density parameter of hot nuclei

    SciTech Connect

    Nerlo-Pomorska, Bozena; Pomorski, Krzysztof; Bartel, Johann

    2006-09-15

    Macroscopic-microscopic calculations have been performed with the Yukawa folded mean field for 134 spherical even-even nuclei and 6 deformed ones at temperatures 0{<=}T{<=}5 MeV and elongations ranging from oblate shapes to the scission configuration of fissioning nuclei. The Strutinsky type free-energy shell corrections for this sample of nuclei and their temperature and deformation dependence are found by a folding procedure in particle-number space. The average dependence of the single-particle level-density parameter on mass number A and isospin I is determined and compared with previous estimates obtained using the relativistic mean-field theory, the Hartree-Fock approximation with the Skyrme effective interaction, and the phenomenological Thomas-Fermi approach adjusted to experimental data. The estimates for the level-density parameter obtained for different deformations are fitted by a liquid-drop type expression.

  16. Quarks in Few Body Nuclei

    NASA Astrophysics Data System (ADS)

    Holt, Roy J.

    2016-03-01

    Electron scattering at very high Bjorken x from hadrons provides an excellent test of models, has an important role in high energy physics, and from nuclei, provides a window into short range correlations. Light nuclei have a key role because of the relatively well-known nuclear structure. The development of a novel tritium target for Jefferson Lab has led to renewed interest in the mass three system. For example, deep inelastic scattering experiments in the light nuclei provide a powerful means to determine the neutron structure function. The isospin dependence of electron scattering from mass-3 nuclei provide information on short range correlations in nuclei. The program using the new tritium target will be presented along with a summary of other experiments aimed at revealing the large-x structure of the nucleon.

  17. Light exotic nuclei with extreme neutron excess and 2 ≤ Z ≤ 8

    NASA Astrophysics Data System (ADS)

    Tarasov, V. N.; Gridnev, K. A.; Schramm, S.; Kuprikov, V. I.; Gridnev, D. K.; Tarasov, D. V.; Godbey, K. S.; Viñas, X.; Greiner, Walter

    2015-07-01

    Using HF + BCS method we study light nuclei with nuclear charge in the range 2 ≤ Z ≤ 8 and lying near the neutron drip line. The HF method uses effective Skyrme forces and allows for axial deformations. We find that the neutron drip line forms stability peninsulas at 18He and 40C. These isotopes are found to be stable against one neutron emission and possess the highest known neutron to proton ratio in stable nuclei.

  18. Low lying electric dipole excitations in nuclei of the rare earth region

    SciTech Connect

    von Brentano, P.; Zilges, A.; Herzberg, R.D. . Inst. fuer Kernphysik); Zamfir, N.V. ); Kneissl, U.; Heil, R.D.; Pitz, H.H. . Inst. fuer Strahlenphysik); Wesselborg, C. . Inst. fuer Kernphysik)

    1992-01-01

    From many experiments with low energy photon scattering on deformed rare earth nuclei we have obtained detailed information about the distribution of electric dipole strength below 4 MeV. Apart from some weaker transitions between 2 and 4 MeV we observed one, and sometimes two, very strong El-groundstate transitions around 1.5 MeV in all examined nuclei. They arise from the de-excitation of the bandheads of the (J[sup [pi

  19. Search for the decay KL to pi0 e+ e- and study of the decay KL to e+ e- gamma gamma

    NASA Astrophysics Data System (ADS)

    Mikelsons, Peter L.

    The particle decay KL-->p0e+e- is a probe of direct CP violation, a phenomenon previously only seen in KL-->pp decays. Understanding direct CP violation is an important part of understanding violation of CP symmetry in general. Experimentally, one of the obstacles to studying KL-->p0e+e- is the rare decay KL-->e+e- gg , which can mimic KL-->p0e+e- . A study of KL-->p0e+e- and KL-->e+e- gg was made as part of the KTeV E799 experiment. K-->p0p0Dalitz decays were used for normalization, and a KL flux of (2.65 +/- 0.18) × 1011 decays was measured. We observed 1578 KL-->e+e- gg candidate events, of which 1516.5 +/- 1.8 remain after background subtraction. These events allow measurement of the Bergström, Massó, and Singer KLgg vertex form- factor parameter, aK*=+0.015+/- 0.12stat.+/-0.03sys. , in mild disagreement with the previously fit value of -0.28 +/- 0.08. This form-factor implies a corresponding branching ratio of G(KL-->e+e- g g,E*g>5 MeV)/G(KL-->all ) = (5.82+/-0.15stat.+/-0.31 sys.+/-0.19BR)× 10-7 , in agreement with the QED prediction. The search for KL-->p0e+e- found two candidate events. However, 1.06 +/- 0.41 events were expected from background processes. Therefore, we do not claim observation of KL-->p0e+e- . Instead, with a single-event sensitivity of 1.00 × 10 -10, we set an upper limit on the KL-->p0e+e- branching ratio of 4.86 × 10-10 at the 90% confidence level.

  20. Superheavy nuclei: from predictions to discovery

    NASA Astrophysics Data System (ADS)

    Oganessian, Yu Ts; Sobiczewski, A.; Ter-Akopian, G. M.

    2017-02-01

    A fundamental outcome of modern nuclear microscopic theory is the prediction of the ‘islands of stability’ in the region of hypothetical superheavy elements (SHEs). In a heavy nucleus, going through the large-scale deformation on the way to fission, the motion of single nucleons is coupled with the collective degrees of freedom of the whole system. The most striking effect of this coupling is obtained for the case of fission of the heaviest nuclei, whose existence is defined entirely by the nuclear structure, i.e. by the shell effect. From this point of view, the synthesis and study of properties of superheavy nuclei (SHN) is a direct way for checking the basic statements of the microscopic nuclear theory. On the nuclide map, SHN outline the border of the heaviest nuclear masses. SHN set the limits of the periodic system of chemical elements. The study of possible existence of SHN in nature offers a way for testing different scenarios of astrophysical nucleosynthesis. The paper elucidates experimental approaches, used for testing the theory predictions made about the SHN, and presents the results of the discovery of the ‘stability island’ of SHEs.

  1. Double Higgs Boson Production via WW Fusion in TeV e+e- Collisions

    NASA Astrophysics Data System (ADS)

    Barger, V.; Han, T.

    The production of two standard model Higgs bosons via the WW fusion process e+e- → bar ve ve HH would test the predicted HHH, HWW and HHWW couplings. At TeV energies this fusion cross section dominates over that from e+e- →ZHH and would give significant event rates for mH ≲ 1/2 MZ at high luminosity e+e- colliders. We evaluate the rates and present the dynamical distributions.

  2. Deformed Brueckner-Hartree-Fock calculations.

    NASA Technical Reports Server (NTRS)

    Ford, W. F.; Braley, R. C.; Becker, R. L.; Patterson, M. R.

    1972-01-01

    The renormalized Brueckner-Hartree-Fock (RBHF) theory for many-body nuclear systems has been generalized to permit calculations for intrinsic states having permanent deformation. Both Hartree-Fock and Brueckner self-consistencies are satisfied, and details of the numerical techniques are discussed. The Hamada-Johnston interaction is used in a study of deformations, binding, size, and separation energies for several nuclei. Electromagnetic transition rates, moments, and electron scattering form factors are calculated using nuclear wave functions obtained by angular momentum projection. Comparison is made to experiment as well as to predictions of ordinary and density-dependent Hartree-Fock theory.

  3. Role of the cluster deformations in explaining the exotic decay half-lives

    NASA Astrophysics Data System (ADS)

    Soylu, A.; Sert, Y.; Bayrak, O.; Boztosun, I.

    2012-09-01

    We investigate the influence of nuclear deformations of the cluster and daughter nuclei on the exotic cluster decay half-lives of ensuremath 221≤ A ≤ 242 for the favored cluster decay of the radioactive nuclei by using the semiclassical WKB method and the Bohr-Sommerfeld quantization condition. The results have also been presented for the spherical nuclei case in order to show clearly the effects of the deformations on the exotic decay half-lives. The half-lives become close to the experimental data when both the deformation of daughter and cluster nuclei are taken into account in the calculations. Furthermore, considering cluster deformations together with the orientation angles of daughter and cluster also provides positive contributions to the results.

  4. Projected shell model study of yrast states of neutron-deficient odd-mass Pr nuclei

    SciTech Connect

    Ibanez-Sandoval, A.; Ortiz, M. E.; Velazquez, V.; Galindo-Uribarri, A.; Hess, P. O.; Sun, Y.

    2011-03-15

    A wide variety of modern instruments allow us to study neutron-deficient nuclei in the A=130 mass region. Highly deformed nuclei have been found in this region, providing opportunities to study the deformed rotational bands. The description of the {sup 125,127,129,131,133}Pr isotopes with the projected shell model is presented in this paper. Good agreement between theory and experiment is obtained and some characteristics are discussed, including the dynamic moment of inertia J{sup (2)}, kinetic moment of inertia J{sup (1)}, the crossing of rotational bands, and backbending effects.

  5. Projected Shell Model Study of Yrast States of Neutron-Deficient Odd-Mass Pr Nuclei

    SciTech Connect

    Ibanes, A.; Ortiz, Mark E; Velazquez, V.; Galindo-Uribarri, Alfredo {nmn}; Hess, P. O.; Sun, Y.

    2011-01-01

    A wide variety of modern instruments allow us to study neutron-deficient nuclei in the A = 130 mass region. Highly deformed nuclei have been found in this region, providing opportunities to study the deformed rotational bands. The description of the 125,127,129,131,133Pr isotopes with the projected shell model is presented in this paper. Good agreement between theory and experiment is obtained and some characteristics are discussed, including the dynamic moment of inertia J (2), kinetic moment of inertia J (1), the crossing of rotational bands, and backbending effects.

  6. Evolution of Structure in Nuclei: Meditation by Sub-Shell Modifications and Relation to Binding Energies

    NASA Astrophysics Data System (ADS)

    Casten, R. F.; Cakirli, R. B.

    2009-03-01

    Understanding the development of configuration mixing, coherence, collectivity, and deformation in nuclei is one of the crucial challenges in nuclear structure physics, and one which has become all the more important with the advent of next generation facilities for the study of exotic nuclei. We will discuss recent work on phase/shape transitional behavior in nuclei, and the role of changes in sub-shell structure in mediating such transitional regions. We will also discuss a newly found, much deeper, link between nuclear structure and nuclear binding energies.

  7. Parity violation in nuclei

    SciTech Connect

    Robertson, R.G.H.

    1980-01-01

    A summary of parity violating effects in nuclei is given. Thanks to vigorous experimental and theoretical effort, it now appears that a reasonably well-defined value for the weak isovector ..pi..-nucleon coupling constant can be obtained. There is one major uncertainty in the analysis, namely the M2/E1 mixing ratio for the 2.79 MeV transition in /sup 21/Ne. This quantity is virtually impossible to calculate reliably and must be measured. If it turns out to be much larger than 1, then a null result in /sup 21/Ne is expected no matter what the weak interaction, so an experimental determination is urgently needed. The most promising approach is perhaps a measurement of the pair internal conversion coefficient. Of course, a direct measurement of a pure isovector case is highly desirable, and it is to be hoped that the four ..delta..T = 1 experiments will be pushed still further, and that improved calculations will be made for the /sup 6/Li case. Nuclear parity violation seems to be rapidly approaching an interesting and useful synthesis.

  8. Gluon density in nuclei

    SciTech Connect

    Ayala, A.L.; Ducati, M.B.G.; Levin, E.M.

    1996-10-01

    In this talk we present our detailed study (theory and numbers) on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather controversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula and estimate the value of the shadowing corrections in this case. Then we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus-nucleus cascade. The initial conditions should be fixed both theoretically and phenomenologically before to attack such complicated problems as the mixture of hard and soft processes in nucleus-nucleus interactions at high energy or the theoretically reliable approach to hadron or/and parton cascades for high energy nucleus-nucleus interaction. 35 refs., 24 figs., 1 tab.

  9. Search for octupole deformation in neutron rich Xe isotopes

    SciTech Connect

    Bentaleb, M.; Schulz, N.; Lubkiewicz, E.

    1994-07-01

    A search for octupole deformation in neutron rich Xe isotopes has been conducted through gamma-ray spectroscopy of primary fragments produced in the spontaneous fission of {sup 248}Cm. The spectrometer consisted of the Eurogam array and a set of 5 LEPS detectors. Level schemes were constructed for Xe isotopes with masses ranging from 138 to 144. Except for {sup 139}Xe, none of them exhibit an alternating parity quasimolecular band, {alpha} feature usually encountered in octupole deformed nuclei. Substantial evidence for reflection asymmetric shape in the intrinsic system of the nucleus exists for the light actinide nuclei.

  10. Tensor Forces and the Ground-State Structure of Nuclei

    SciTech Connect

    Rocco Schiavilla

    2007-03-01

    Two-nucleon momentum distributions are calculated for the ground states of nuclei with mass number A {le} 8, using accurate variational Monte Carlo wave functions derived from a realistic Hamiltonian with two- and three-nucleon potentials. The momentum distribution of 'np' pairs is found to be much larger than that of 'pp' pairs for values of the relative momentum in the range (300--600) MeV/c and vanishing total momentum. This large difference, more than an order of magnitude, is seen in all nuclei considered, and has a universal character originating from the tensor components present in any realistic nucleon-nucleon potential. The correlations induced by the tensor force strongly influence the structure of 'np' pairs, which are known to be predominantly in deuteron-like states, while they are ineffective for 'pp' pairs, which are mostly in {sup 1}S{sub 0} states. These features should be easily observable in two-nucleon knock-out processes, for example in A(e,e{prime} np) and A(e,e{prime} pp) reactions.

  11. Survey of Reflection-Asymmetric Nuclear Deformations

    NASA Astrophysics Data System (ADS)

    Olsen, Erik; Cao, Yuchen; Nazarewicz, Witold; Schunck, Nicolas

    2016-09-01

    Due to spontaneous symmetry breaking it is possible for a nucleus to have a deformed shape in its ground state. It is theorized that atoms whose nuclei have reflection-asymmetric or pear-like deformations could have non-zero electric dipole moments (EDMs). Such a trait would be evidence of CP-violation, a feature that goes beyond the Standard Model of Physics. It is the purpose of this project to predict which nuclei exhibit a reflection-asymmetric deformation and which of those would be the best candidates for an EDM measuring experiment. Using nuclear Density Functional Theory along with the new computer code AxialHFB and massively parallel computing we calculated ground state nuclear properties for thousands of even-even nuclei across the nuclear chart: from light to superheavy and from stable to short-lived systems. Six different Energy Density Functionals (EDFs) were used to assess systematic errors in our calculations. These results are to be added to the website Massexplorer (http://massexplorer.frib.msu.edu/) which contains results from earlier mass table calculations and information on single quasiparticle energies.

  12. Bunionette deformity.

    PubMed

    Cohen, Bruce E; Nicholson, Christopher W

    2007-05-01

    The bunionette, or tailor's bunion, is a lateral prominence of the fifth metatarsal head. Most commonly, bunionettes are the result of a widened 4-5 intermetatarsal angle with associated varus of the metatarsophalangeal joint. When symptomatic, these deformities often respond to nonsurgical treatment methods, such as wider shoes and padding techniques. When these methods are unsuccessful, surgical treatment is based on preoperative radiographs and associated lesions, such as hyperkeratoses. In rare situations, a simple lateral eminence resection is appropriate; however, the risk of recurrence or overresection is high with this technique. Patients with a lateral bow to the fifth metatarsal are treated with a distal chevron-type osteotomy. A widened 4-5 intermetatarsal angle often requires a diaphyseal osteotomy for correction.

  13. Stem cell mechanics: Auxetic nuclei

    NASA Astrophysics Data System (ADS)

    Wang, Ning

    2014-06-01

    The nuclei of naive mouse embryonic stem cells that are transitioning towards differentiation expand when the cells are stretched and contract when they are compressed. What drives this auxetic phenotype is, however, unclear.

  14. Generalized parton distributions in nuclei

    SciTech Connect

    Vadim Guzey

    2009-12-01

    Generalized parton distributions (GPDs) of nuclei describe the distribution of quarks and gluons in nuclei probed in hard exclusive reactions, such as e.g. deeply virtual Compton scattering (DVCS). Nuclear GPDs and nuclear DVCS allow us to study new aspects of many traditional nuclear effects (nuclear shadowing, EMC effect, medium modifications of the bound nucleons) as well as to access novel nuclear effects. In my talk, I review recent theoretical progress in the area of nuclear GPDs.

  15. Exotic Orbital Modes in Nuclei

    NASA Astrophysics Data System (ADS)

    von Neumann-Cosel, P.

    2003-06-01

    Experimental evidence for two types of collective excitations in nuclei generated by orbital motion is discussed, viz. a magnetic quadrupole twist mode observed in 180° electron scattering experiments and a toroidal electric dipole mode. The latter may be a source of low-energy pygmy dipole resonances observed in many nuclei. This is discussed in detail for the example of 208Pb based on the recent finding of a resonance at particle threshold in a high-resolution (γ, γ') experiment.

  16. The nature of comet nuclei

    NASA Technical Reports Server (NTRS)

    Sykes, Mark V.; Walker, Russell G.

    1992-01-01

    The icy-conglomerate model of comet nuclei has dominated all others since its introduction. It provided a basis for understanding the non-gravitational motions of comets which had perplexed dynamicists up to that time, and provided a focus for understanding cometary composition and origin. The image of comets as dirty snowballs was quickly adopted. Comet nuclei including their trail mass loss rates and refractory to volatile mass ratios are described.

  17. They're M-e-e-elting!: An Investigation of Glacial Retreat in Antarctica

    ERIC Educational Resources Information Center

    Bugg, Samuel R., IV; Constible, Juanita; Kaput, Marianne; Lee, Richard E., Jr.

    2007-01-01

    In this article, the authors describe the mechanics of They're M-e-e-elting!, an activity wherein middle school students can simulate glacial retreat in Antarctica. They're M-e-e-elting! allows students to melt glaciers, change the water level and salinity of the Southern Ocean, and examine alterations to the Antarctic food web--all without…

  18. Hadronic cross sections measurement with the SND detector at VEPP-2000 e+e- collider

    NASA Astrophysics Data System (ADS)

    Achasov, M. N.; Barnyakov, A. Yu; Barnyakov, M. Yu; Beloborodov, K. I.; Berdyugin, A. V.; Berkaev, D. E.; Blinov, V. E.; Bobrovnikov, V. S.; Bogdanchikov, A. G.; Botov, A. A.; Buzykaev, A. R.; Dimova, T. V.; Druzhinin, V. P.; Golubev, V. B.; Kardapoltsev, L. V.; Kirpotin, A. N.; Kononov, S. A.; Koop, I. A.; Korol, A. A.; Koshuba, S. V.; Kovrizhin, D. P.; Kravchenko, D. P.; Kupich, A. S.; Lysenko, A. P.; Martin, K. A.; Obrazovsky, A. E.; Onuchin, A. P.; Pakhtusova, E. V.; Kharlamov, A. G.; Romanov, A. L.; Senchenko, A. I.; Shatunov, P. Yu; Shatunov, Yu M.; Shtol, D. A.; Shwartz, D. B.; Silagadze, Z. K.; Skrinsky, A. N.; Surin, I. K.; Tikhonov, Yu A.; Usov, Yu V.; Vasiljev, A. V.; Zemlyansky, I. M.

    2015-11-01

    The cross sections {{{e}}}+{{{e}}}-\\to {π }+{π }-, 3π , 4π , ω {π }0, K+K-, η {π }+{π }-, η γ , {{p}}\\bar{{{p}}},{{n}}\\bar{{{n}}} have been measured with the spherical neutral detector at the VEPP-2000 e+e- collider in the energy range from 0.3 to 2.0 GeV.

  19. They're M-e-e-elting!: An Investigation of Glacial Retreat in Antarctica

    ERIC Educational Resources Information Center

    Bugg, Samuel R., IV; Constible, Juanita; Kaput, Marianne; Lee, Richard E., Jr.

    2007-01-01

    In this article, the authors describe the mechanics of They're M-e-e-elting!, an activity wherein middle school students can simulate glacial retreat in Antarctica. They're M-e-e-elting! allows students to melt glaciers, change the water level and salinity of the Southern Ocean, and examine alterations to the Antarctic food web--all without…

  20. Octupole deformation in the nuclear chart based on the 3D Skyrme Hartree-Fock plus BCS model

    NASA Astrophysics Data System (ADS)

    Ebata, Shuichiro; Nakatsukasa, Takashi

    2017-06-01

    We have performed a systematic study of the ground state for 1002 even-even nuclei in which 28 octupole-deformed nuclei are found. The interplay between the spatial deformation and the pairing correlation plays an important role in the nuclear structure. Our model is based on the Skyrme Hartree-Fock plus BCS model represented in the three-dimensional Cartesian coordinate space, which can describe any kind of nuclear shape. The quadrupole and octupole deformed nuclei appear in the mass region with characteristic neutron and proton numbers which are consistent with previous studies. In our results, there appear only pear shapes (β 30) in the octupole deformed nuclei. We investigate the potential energy surfaces as functions of the octupole deformations (β 3m ; m = 0, 1, 2, 3), which tells us that 220Rn also has local minima in the β 31 and β 32 potential energy surfaces.

  1. ρ''s in analyzing e+e- annihilation: Mark III, LASS, and ARGUS data

    NASA Astrophysics Data System (ADS)

    Achasov, N. N.; Kozhevnikov, A. A.

    1997-03-01

    The results of an analysis of some recent data on the reactions e+e--->π+π-π+π-, e+e--->π+π-π0π0 with the subtracted ωπ0 events, e+e--->ωπ0, e+e--->ηπ+π-, e+e--->π+π-, K-p-->π+π-Λ, the decays J/ψ-->π+π-π0, τ--->ντπ+π-π-π0, and τ--->ντωπ-, upon taking into account both the strong energy dependence of the partial widths on energy and the previously neglected mixing of the ρ-type resonances, are presented. The above effects are shown to exert an essential influence on the specific values of masses and coupling constants of heavy resonances and, hence, are necessary to be accounted for in establishing their true nature.

  2. Structural and decay properties of Z = 132, 138 superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Rather, Asloob A.; Ikram, M.; Usmani, A. A.; Kumar, Bharat; Patra, S. K.

    2016-12-01

    In this paper, we analyze the structural properties of Z = 132 and Z = 138 superheavy nuclei within the ambit of axially deformed relativistic mean-field framework with NL3 * parametrization and calculate the total binding energies, radii, quadrupole deformation parameter, separation energies, density distributions. We also investigate the phenomenon of shape coexistence by performing the calculations for prolate, oblate and spherical configurations. For clear presentation of nucleon distributions, the two-dimensional contour representation of individual nucleon density and total matter density has been made. Further, a competition between possible decay modes such as α-decay, β-decay and spontaneous fission of the isotopic chain of superheavy nuclei with Z = 132 within the range 312 ≤ A ≤ 392 and 318 ≤ A ≤ 398 for Z = 138 is systematically analyzed within self-consistent relativistic mean-field model. From our analysis, we inferred that the α-decay and spontaneous fission are the principal modes of decay in majority of the isotopes of superheavy nuclei under investigation apart from β-decay as dominant mode of decay in 318-322138 isotopes.

  3. Microscopic formulation of the interacting boson model for rotational nuclei

    SciTech Connect

    Nomura, Kosuke; Shimizu, Noritaka; Otsuka, Takaharu; Guo, Lu

    2011-04-15

    We propose a novel formulation of the interacting boson model (IBM) for rotational nuclei with axially symmetric, strong deformation. The intrinsic structure represented by the potential-energy surface (PES) of a given multinucleon system has a certain similarity to that of the corresponding multiboson system. Based on this feature, one can derive an appropriate boson Hamiltonian, as already reported. This prescription, however, has a major difficulty in the rotational spectra of strongly deformed nuclei: the bosonic moment of inertia is significantly smaller than the corresponding nucleonic one. We present that this difficulty originates in the difference between the rotational response of a nucleon system and that of the corresponding boson system, and could arise even if the PESs of the two systems were identical. We further suggest that the problem can be solved by implementing the L{center_dot}L term into the IBM Hamiltonian, with the coupling constant derived from the cranking approach of Skyrme mean-field models. The validity of the method is confirmed for rare-earth and actinoid nuclei, as their experimental rotational yrast bands are reproduced nicely.

  4. Measurement of the e + e -→ π + π - π 0 and e + e -→ ωπ + π - reactions in the energy interval 1350 2400 MeV

    NASA Astrophysics Data System (ADS)

    Antonelli, A.; Baldini, R.; Biagini, M. E.; Calcaterra, S.; Schioppa, M.; Bisello, D.; Busetto, G.; Castro, A.; Nigro, M.; Pescara, L.; Sartori, P.; Stanco, L.; Augustin, J. E.; Ayach, L.; Cosme, G.; Couchot, F.; Fulda, F.; Grosdidier, G.; Jean-Marie, B.; Lepeltier, V.; Szklarz, G.

    1992-03-01

    The cross sections for e + e -→ π + π - π 0 and e + e -→ ωπ + π - have been measured in the 1.35 ≦sqrt s ≦2.4 GeV range from 1900 nb-1 collected by DM2 at DCI. The second process proceeds via a resonant state at ≈- 1660 MeV/c2, ≈- 280 MeV/c2 wide. The first one is larger than a VDM extrapolation from the ω-ϕ peaks and, although does not show any clear structure, is compatible with the presence of the above resonance.

  5. Interpretation of the Processes 3He(e,e'p)2H and 3He(e,e'p)(pn) at High Missing Momenta

    NASA Astrophysics Data System (ADS)

    Ciofi Degli Atti, C.; Kaptari, L. P.

    2005-07-01

    Using realistic three-body wave functions corresponding to the AV18 interaction, it is shown that the effects of the final state interaction in the exclusive processes 3He(e,e'p)2H and 3He(e,e'p)(pn), can be successfully treated in terms of a generalized eikonal approximation based upon the direct calculation of the Feynman diagrams describing the rescattering of the struck nucleon. The relevant role played by the double rescattering contribution at high values of the missing momentum is illustrated.

  6. Interpretation of the processes 3He(e,e'p)2H and 3He(e,e'p)(pn) at high missing momenta.

    PubMed

    Ciofi degli Atti, C; Kaptari, L P

    2005-07-29

    Using realistic three-body wave functions corresponding to the AV18 interaction, it is shown that the effects of the final state interaction in the exclusive processes 3He(e,e'p)2H and 3He(e,e'p)(pn), can be successfully treated in terms of a generalized eikonal approximation based upon the direct calculation of the Feynman diagrams describing the rescattering of the struck nucleon. The relevant role played by the double rescattering contribution at high values of the missing momentum is illustrated.

  7. Separation of U-238 and Np-237 nuclei by gamma-quanta intermediate energies

    NASA Astrophysics Data System (ADS)

    Kazakov, A. A.; Kezerashvili, G. Y.; Lazareva, T. Y.; Nedorezov, V. G.; Skrinskiy, A. N.; Sudov, A. S.; Tumaykin, G. M.; Shatunov, Y. M.

    1986-01-01

    A system employing a beam of backscattered Compton quanta based on the e(+)e(-) accumulating complex and an LTI-701 solid state laser is employed to measure the average photoseparation and separability cross sections of U234 and Np237 nuclei at energies ranging from 150 to 170 MeV. The findings contradict the predictions of existing models based on photon-meson nuclear excitation, and suggest that one of the most probable mechanisms underlying the excitation of nuclei by gamma quanta with intermediate energies, in addition to the photogeneration of pions, is the generation of e(+)e(-) pairs in the field of the nucleus: the gamma quanta wavelength energies in this region becomes comparable to the nucleon dimension, so that collective nuclear excitations are generally suppressed.

  8. Theoretical studies on the modes of decay of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Santhosh, K. P.; Nithya, C.

    2016-11-01

    The decay modes of recently synthesized superheavy nuclei are investigated by comparing the α -decay half-lives with the spontaneous fission half-lives. α -decay half-lives are calculated using the Coulomb and proximity potential model for deformed nuclei (CPPMDN). The agreement between theoretical and experimental α half-lives shows the predictability of the CPPMDN in the superheavy region. A modified formula is proposed for calculating the spontaneous fission half-lives including the shell correction. The agreement between theoretical predictions and experimental results of spontaneous fission half-lives is satisfactory for heavy and superheavy nuclei ranging from Th to Fl. A comparison between the spontaneous fission half-lives computed using eight different formalisms is performed for even-even superheavy nuclei in the range of 108 ≤Z ≤120 . Even though all these models can reproduce the experimental spontaneous fission half-lives, model-to-model variations in predicting the fission half-lives in superheavy region is evident from the study.

  9. Study of resonant structures in a deformed mean field by the contour deformation method in momentum space

    NASA Astrophysics Data System (ADS)

    Hagen, G.; Vaagen, J. S.

    2006-03-01

    Solution of the momentum space Schrödinger equation in the case of deformed fields is being addressed. In particular it is shown that a complete set of single-particle states that includes bound, resonant, and complex continuum states may be obtained by the contour deformation method. This generalized basis in the complex energy plane is known as a Berggren basis. The momentum space Schrödinger equation is an integral equation that is easily solved by matrix diagonalization routines even for the case of deformed fields. The method is demonstrated for axial symmetry and a fictitious “deformed He5” but may be extended to more general deformation and applied to truly deformed halo nuclei.

  10. Coupled Simulations of Texture Evolution during Deformation and Recrystallization of FCC and BCC Metals

    SciTech Connect

    Radhakrishnan, Balasubramaniam; Gorti, Sarma B

    2008-01-01

    Thermo-mechanical processing to produce optimum grain structure and texture is key to the successful utilization of commercial aluminum alloys and steels as sheet products. Several modeling techniques have been developed in the past with a reasonably good predictive capability for bulk deformation textures. However, prediction of texture evolution during recrystallization remains very challenging because of uncertainties involved in predicting the mechanisms that lead to nuclei formation and crystallographic orientations of the nuclei, and the uncertainties involved in predicting the grain boundary properties that determine the growth kinetics of the nuclei. We present some of our recent work in modeling the recrystallization textures following hot deformation in polycrystalline BCC and FCC metals.

  11. Cavitation inception from bubble nuclei.

    PubMed

    Mørch, K A

    2015-10-06

    The tensile strength of ordinary water such as tap water or seawater is typically well below 1 bar. It is governed by cavitation nuclei in the water, not by the tensile strength of the water itself, which is extremely high. Different models of the nuclei have been suggested over the years, and experimental investigations of bubbles and cavitation inception have been presented. These results suggest that cavitation nuclei in equilibrium are gaseous voids in the water, stabilized by a skin which allows diffusion balance between gas inside the void and gas in solution in the surrounding liquid. The cavitation nuclei may be free gas bubbles in the bulk of water, or interfacial gaseous voids located on the surface of particles in the water, or on bounding walls. The tensile strength of these nuclei depends not only on the water quality but also on the pressure-time history of the water. A recent model and associated experiments throw new light on the effects of transient pressures on the tensile strength of water, which may be notably reduced or increased by such pressure changes.

  12. Cavitation inception from bubble nuclei

    PubMed Central

    Mørch, K. A.

    2015-01-01

    The tensile strength of ordinary water such as tap water or seawater is typically well below 1 bar. It is governed by cavitation nuclei in the water, not by the tensile strength of the water itself, which is extremely high. Different models of the nuclei have been suggested over the years, and experimental investigations of bubbles and cavitation inception have been presented. These results suggest that cavitation nuclei in equilibrium are gaseous voids in the water, stabilized by a skin which allows diffusion balance between gas inside the void and gas in solution in the surrounding liquid. The cavitation nuclei may be free gas bubbles in the bulk of water, or interfacial gaseous voids located on the surface of particles in the water, or on bounding walls. The tensile strength of these nuclei depends not only on the water quality but also on the pressure–time history of the water. A recent model and associated experiments throw new light on the effects of transient pressures on the tensile strength of water, which may be notably reduced or increased by such pressure changes. PMID:26442138

  13. A multilayer ΔE-E R telescope for breakup reactions at energies around the Coulomb barrier

    NASA Astrophysics Data System (ADS)

    Ma, Nan-Ru; Lin, Cheng-Jian; Wang, Jian-Song; Yang, Lei; Wang, Dong-Xi; Zheng, Lei; Xu, Shi-Wei; Sun, Li-Jie; Jia, Hui-Ming; Ma, Jun-Bing; Ma, Peng; Jin, Shi-Lun; Bai, Zhen; Yang, Yan-Yun; Xu, Xin-Xing; Zhang, Gao-Long; Yang, Feng; He, Jian-Jun; Zhang, Huan-Qiao; Liu, Zu-Hua

    2016-11-01

    The breakup reactions of weakly-bound nuclei at energies around the Coulomb barrier and the corresponding coupling effect on the other reaction channels are hot topics nowadays. To overcome the difficulty in identifying both heavier and lighter fragments simultaneously, a new kind of ionization-chamber based detector telescope has been designed and manufactured. It consists of a PCB ionization chamber and three different thickness silicon detectors installed inside the chamber, which form a multilayer ΔE-E R telescope. The working conditions were surveyed by using an α source. An in-beam test experiment shows that the detector has good particle identification for heavy particles like 17F and 16O as well as light particles like protons and alpha particles. The measured quasi-elastic scattering angular distribution and the related discussions for 17F+208Pb are presented. Supported by National Key Basic Research Development Program of China (2013CB834404) and National Natural Science Foundation of China (11375268, 11475263, U1432127, U1432246).

  14. Investigation of beam self-polarization in the future e+e- circular collider

    DOE PAGES

    Gianfelice-Wendt, E.

    2016-10-24

    The use of resonant depolarization has been suggested for precise beam energy measurements (better than 100 keV) in the e+e- Future Circular Collider (FCC-e+e-) for Z and WW physics at 45 and 80 GeV beam energy respectively. Longitudinal beam polarization would benefit the Z peak physics program; however it is not essential and therefore it will be not investigated here. In this paper the possibility of self-polarized leptons is considered. As a result, preliminary results of simulations in presence of quadrupole misalignments and beam position monitors (BPMs) errors for a simplified FCC-e+e- ring are presented.

  15. Odd-odd deformed proton emitters.

    PubMed

    Ferreira, L S; Maglione, E

    2001-02-26

    Proton decay from odd-odd deformed nuclei is a long-standing unsolved problem. We present for the first time an exact solution using single particle Nilsson resonances. The lifetime is found to depend strongly on the single particle level occupied by the unpaired neutron, allowing a clear assignment of its Nilsson level. The emitters 112Cs, 140Ho, 150Lu, and 150Lu(m) are considered. The agreement with the experimental data is very good with deformations 0.1deformation 0.16

  16. Bands and Isomers in Neutron-Rich Rare-Earth Nuclei in PHF Model

    NASA Astrophysics Data System (ADS)

    Praharaj, C. R.; Ghorui, S. K.; Naik, Z.; Sahu, B. B.

    Rotational structures of neutron-rich Gd and Dy nuclei in the REE peak region are studied with deformed Hartee-Fock (HF) and angular momentum (J) projection model. Spectra of ground band and a few more excited, positive and negative parity bands have been studied up to high spin values. Some 4-quasiparticle K-isomeric bands and their electromagnetic properties are predicted.

  17. Shape phase transitions in odd-A nuclei

    SciTech Connect

    Alonso, C. E.; Arias, J. M.; Fortunato, L.; Vitturi, A.

    2008-11-11

    We investigate shape phase transitions in odd nuclei within the Interacting Boson Fermion Model. Special attention is given to the case of the transition from the vibrational behaviour to the stable axial deformation. The odd particle is assumed to be moving in the three single particle orbitals j = 1/2,3/2,5/2 with a boson-fermion Hamiltonian that leads to the occurrence of the SU{sup BF}(3) boson-fermion symmetry when the boson part approaches the SU(3) condition. Both energy spectra and electromagnetic transitions show characteristic patterns similar to those displayed by the even nuclei at the corresponding critical point. The role of the additional particle in characterizing the properties of the critical points in finite quantal systems is investigated by resorting to the formalism based on the intrinsic frame.

  18. Perspectives of Physics of Exotic Nuclei Beyond the Shell Evolution

    NASA Astrophysics Data System (ADS)

    Otsuka, Takaharu

    2015-11-01

    I present one of the possible paradigm shifts with exotic nuclei. This is the shell evolution due to nuclear forces, such as tensor, central and three-nucleon forces. I shall present major points with the N=34 magic number confirmed in 54Ca by RIBF of RIKEN very recently, after the theoretical prediction made in 2001. The shell evolution has been generalized to phenomena caused by massive particle-hole excitations, being referred to as Type II Shell Evolution. This can be found in 68,70Ni. In particular, the shape coexistence of spherical, oblate and prolate shapes is suggested theoretically. Thus, the perspectives of physics with exotic nuclei is being expanded further from single-particle aspects to shapes/deformation, changing the landscape of nuclear structure.

  19. Ultra-High Spin Spectroscopy In Er Nuclei

    SciTech Connect

    Simpson, J.

    2008-11-11

    The discoveries observed in the ongoing conflict between collective and single-particle nuclear behaviour with increasing angular momentum have driven the field of nuclear spectroscopy for many decades and have given rise to new nuclear phenomena. Recently a new frontier of {gamma} spectroscopy at ultra-high spin has been opened in the rare-earth region with rotational bands that bypass the classic band-terminating states that appear at spin 45({Dirac_h}/2{pi}) in the N 90 Er nuclei. These weakly populated rotational structures have characteristics of triaxial strongly-deformed bands. Such structures have been observed in {sup 157,158,160}Er, following a series of experiments using the Gammasphere spectrometer. These observations herald a return to collective excitations at spins of about 50 to 65({Dirac_h}/2{pi}). This talk reviews the status of the spectroscopy and understanding of the observed structures in these Er and neighbouring nuclei.

  20. Decay rates of spherical and deformed proton emitters

    SciTech Connect

    Davids, C. N.; Esbensen, H.

    1999-11-23

    Using Green's function techniques, the authors derive expressions for the width of a proton decaying state in spherical and deformed nuclei. The authors show that the proton decay widths calculated by the exact expressions of Maglione et al. are equivalent to the distorted wave expressions of Bugrov et al., and that of {angstrom} berg et al. in the spherical case.

  1. Nuclear Hexadecapole Deformation Effects on the Production of Super-Heavy Elements

    NASA Astrophysics Data System (ADS)

    Wang, Nan; Dou, Liang; Zhao, En-Guang; Werner, Scheid

    2010-06-01

    We investigate the effects of the nuclear hexadecapole deformations on the interaction potentials between nuclei, the driving potentials and the fusion probabilities for some cold fusion reactions leading to super-heavy elements. It is found that nuclear hexadecapole deformations change significantly the structure of the driving potentials and the fusion probabilities for some reaction channels.

  2. Preferential acceleration and magnetic field enhancement in plasmas with e+/e- beam injection

    NASA Astrophysics Data System (ADS)

    Huynh, Cong Tuan; Ryu, Chang-Mo

    2016-03-01

    A theoretical model of current filaments predicting preferential acceleration/deceleration and magnetic field enhancement in a plasma with e+/e- beam injection is presented. When the e+/e- beams are injected into a plasma, current filaments are formed. The beam particles are accelerated or decelerated depending on the types of current filaments in which they are trapped. It is found that in the electron/ion ambient plasma, the e+ beam particles are preferentially accelerated, while the e- beam particles are preferentially decelerated. The preferential particle acceleration/deceleration is absent when the ambient plasma is the e+/e- plasma. We also find that the particle momentum decrease can explain the magnetic field increase during the development of Weibel/filamentation instability. Supporting simulation results of particle acceleration/deceleration and magnetic field enhancement are presented. Our findings can be applied to a wide range of astrophysical plasmas with the e+/e- beam injection.

  3. Observation of the h(c)(1P) Using e+ e- collisions above the DD threshold.

    PubMed

    Pedlar, T K; Cronin-Hennessy, D; Hietala, J; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Xiao, T; Martin, L; Powell, A; Wilkinson, G; Mendez, H; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Hu, D; Moziak, B; Napolitano, J; Ecklund, K M; Insler, J; Muramatsu, H; Park, C S; Pearson, L J; Thorndike, E H; Ricciardi, S; Thomas, C; Artuso, M; Blusk, S; Mountain, R; Skwarnicki, T; Stone, S; Zhang, L M; Bonvicini, G; Cinabro, D; Lincoln, A; Smith, M J; Zhou, P; Zhu, J; Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Randrianarivony, K; Tatishvili, G; Briere, R A; Vogel, H; Onyisi, P U E; Rosner, J L; Alexander, J P; Cassel, D G; Das, S; Ehrlich, R; Gibbons, L; Gray, S W; Hartill, D L; Heltsley, B K; Kreinick, D L; Kuznetsov, V E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Sun, W M; Yelton, J; Rubin, P; Lowrey, N; Mehrabyan, S; Selen, M; Wiss, J; Libby, J; Kornicer, M; Mitchell, R E; Shepherd, M R; Tarbert, C M; Besson, D

    2011-07-22

    Using 586  pb(-1) of e+ e- collision data at E(c.m.) = 4170  MeV, produced at the Cornell Electron Storage Ring collider and collected with the CLEO-c detector, we observe the process e+ e- → π+ π- h(c)(1P). We measure its cross section to be 15.6±2.3±1.9±3.0  pb, where the third error is due to the external uncertainty on the branching fraction of ψ(2S) → π0 h(c)(1P), which we use for normalization. We also find evidence for e+ e- → ηh(c)(1P) at 4170 MeV at the 3σ level and see hints of a rise in the e+ e- → π+ π- h(c)(1P) cross section at 4260 MeV.

  4. A tale of two portals: testing light, hidden new physics at future e + e - colliders

    NASA Astrophysics Data System (ADS)

    Liu, Jia; Wang, Xiao-Ping; Yu, Felix

    2017-06-01

    We investigate the prospects for producing new, light, hidden states at a future e + e - collider in a Higgsed dark U(1) D model, which we call the Double Dark Portal model. The simultaneous presence of both vector and scalar portal couplings immediately modifies the Standard Model Higgsstrahlung channel, e + e - → Zh, at leading order in each coupling. In addition, each portal leads to complementary signals which can be probed at direct and indirect detection dark matter experiments. After accounting for current constraints from LEP and LHC, we demonstrate that a future e + e - Higgs factory will have unique and leading sensitivity to the two portal couplings by studying a host of new production, decay, and radiative return processes. Besides the possibility of exotic Higgs decays, we highlight the importance of direct dark vector and dark scalar production at e + e - machines, whose invisible decays can be tagged from the recoil mass method.

  5. Chromatin structure in barley nuclei.

    PubMed

    Mithieux, G; Roux, B

    1983-10-03

    In order to study the chromatin structure of a higher plant we used a high-yield method, which allows one to obtain up to 10(9) nuclei/kg fresh barley leaves. Significant amounts of low-ionic-strength-soluble chromatin can be extracted from these nuclei. Physicochemical properties were examined and discussed. Electric birefringence allowed us to observe the same transition in electro-optical properties as has been observed for animal chromatin, and suggested the existence of a symetrical structure occurring for approximately six nucleosomes. Circular dichroism showed that barley oligonucleosomes exhibit a higher molar ellipticity at 282 nm than total soluble chromatin and than their animal counterparts.

  6. SUSY effects in Higgs production at high energy e+ e- colliders

    NASA Astrophysics Data System (ADS)

    Cao, Junjie; Han, Chengcheng; Ren, Jie; Wu, Lei; Yang, Jin-Min; Zhang, Yang

    2016-11-01

    Considering the constraints from collider experiments and dark matter detection, we investigate the SUSY effects in the Higgs production channels e+ e- → Zh at an e+ e- collider with a center-of-mass energy above 240 GeV and γγ → h → bb¯ at a photon collider with a center-of-mass energy above 125 GeV. In the parameter space allowed by current experiments, we find that the SUSY corrections to e+ e- → Zh can reach a few percent and the production rate of γγ → h → bb¯ can be enhanced by a factor of 1.2 over the SM prediction. We also calculate the exotic Higgs production e+ e-→ Zh1 in the next-to-minimal supersymmetric model (NMSSM) (h is the SM-like Higgs, h1 is the CP-even Higgs bosons which can be much lighter than h). We find that at a 250 GeV e+ e- collider the production rates of e+ e-→ Zh1 can reach 60 fb. Supported by National Natural Science Foundation of China (NNSFC)(10821504, 11222548, 11305049, 11135003), Program for New Century Excellent Talents in University, and ARC Center of Excellence for Particle Physics at Tera-scale. C. Han is supported by World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan

  7. Nucleon and nucleon-pair momentum distributions in A ≤12 nuclei

    NASA Astrophysics Data System (ADS)

    Wiringa, R. B.; Schiavilla, R.; Pieper, Steven C.; Carlson, J.

    2014-02-01

    Background: Momentum distributions of individual nucleons and nucleon pairs reflect features of the short-range structure of nuclei and provide useful insights into various reactions on nuclei, such as (e,e'p) and (e,e'pp/pn) electrodisintegration processes or neutrino-nucleus interaction experiments. Purpose: To provide the nuclear physics community with the results (available online) of a systematic study of single-nucleon momentum distributions and nucleon-pair and nucleon-cluster momentum distributions for A ≤12 nuclei. Method: The realistic Argonne v18 two-nucleon and Urbana X three-nucleon potentials are used to generate accurate variational Monte Carlo wave functions for the A ≤12 nuclei; quantum Monte Carlo methods are used to calculate the momentum distributions. Results: Single-nucleon distributions are given, broken down into proton and neutron components and spin-up and spin-down components where appropriate. Nucleon-pair momentum distributions are given either in pair spin and isospin ST projection or for pp, pn, and nn pairs. Nucleon-cluster momentum distributions include dp in 3He, tp and dd in 4He, αd in 6Li, αt in 7Li, and αα in 8Be. Conclusions: The momentum distributions exhibit common characteristic shapes, with tensor correlations (or lack thereof) playing a dominant role in the 1.5-3 fm-1 range, while spin-isospin correlations dominate at higher momenta.

  8. Surface properties of neutron-rich exotic nuclei: A source for studying the nuclear symmetry energy

    SciTech Connect

    Gaidarov, M. K.; Antonov, A. N.; Sarriguren, P.; Moya de Guerra, E.

    2011-09-15

    We study the correlation between the thickness of the neutron skin in finite nuclei and the nuclear symmetry energy for isotopic chains of even-even Ni, Sn, and Pb nuclei in the framework of the deformed self-consistent mean-field Skyrme HF + BCS method. The symmetry energy, the neutron pressure, and the asymmetric compressibility in finite nuclei are calculated within the coherent density fluctuation model using the symmetry energy as a function of density within the Brueckner energy density functional. The mass dependence of the nuclear symmetry energy and the neutron-skin thickness are also studied together with the role of the neutron-proton asymmetry. A correlation between the parameters of the equation of state (symmetry energy and its density slope) and the neutron skin is suggested in the isotopic chains of Ni, Sn, and Pb nuclei.

  9. Experimental level-structure determination in odd-odd actinide nuclei

    SciTech Connect

    Hoff, R.W.

    1985-04-04

    The status of experimental determination of level structure in odd-odd actinide nuclei is reviewed. A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei is applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation are derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings are used. Calculated and experimental level structures for /sup 238/Np, /sup 244/Am, and /sup 250/Bk are compared, as well as those for several nuclei in the rare-earth region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Applications of this modeling technique are discussed.

  10. Convergence of the moments of inertia in f-p-g shell nuclei

    NASA Astrophysics Data System (ADS)

    Tabor, S. L.

    1992-01-01

    A survey of the kinematic moments of inertia of A~=80 nuclei shows a tendency to converge toward the rigid-body values of 20 to 25 ħ2/MeV at rotational frequencies above 0.6 MeV/ħ. The moments of the even-even isotopes approach the convergence zone from much lower values. The farther from the center of the shell, the lower the initial values are and the more rapid is the rise. By contrast, the moments of inertia of the odd-odd nuclei start from higher values and decrease into the convergence zone. The values for odd-A nuclei are generally intermediate, usually starting somewhat below the final value and increasing into the 20 to 25 ħ2/MeV region. The quadrupole deformations inferred from lifetimes in the even-even nuclei show no systematic change with spin, in contrast to the moments of inertia.

  11. Description of odd-mass nuclei within the interacting boson-fermion model based on the Gogny energy density functional

    NASA Astrophysics Data System (ADS)

    Nomura, K.; Rodríguez-Guzmán, R.; Robledo, L. M.

    2017-07-01

    Spectroscopic properties of odd-mass nuclei are studied within the framework of the interacting boson-fermion model (IBFM) with parameters based on the Hartree-Fock-Bogoliubov (HFB) approximation. The parametrization D1M of the Gogny energy density functional (EDF) was used at the mean-field level to obtain the deformation energy surfaces for the considered nuclei in terms of the quadrupole deformations (β ,γ ). In addition to the energy surfaces, both single-particle energies and occupation probabilities were used as a microscopic input for building the IBFM Hamiltonian. Only three strength parameters for the particle-boson-core coupling are fitted to experimental spectra. The IBFM Hamiltonian is then used to compute the energy spectra and electromagnetic transition rates for selected odd-mass Eu and Sm nuclei as well as for 195Pt and 195Au. A reasonable agreement with the available experimental data is obtained for the considered odd-mass nuclei.

  12. Properties of fission fragments for Z =112 -116 superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Kaur, Gurjit; Sandhu, Kirandeep; Sharma, Manoj K.

    2016-07-01

    The dynamical cluster decay model (DCM) is applied to understand the dynamics of 48Ca+238U,244Pu,248Cm reactions at comparable excitation energies across the barrier. To understand the capture stage of *286112 ,*292114 , and *296116 nuclei, the compound nucleus formation probability is calculated. The indication of PC N<1 in the DCM framework demonstrates the fact that some competing process such as quasifission may occur at the capture stage of the 48Ca induced reactions. To understand this further, the comparative decay analysis of *286112 ,*292114 and *296116 , nuclei is carried out using β2 i deformations within hot optimum orientation criteria, and the calculated fission cross sections find nice agreement with available data. The fission mass distribution shows a double humped structure where a symmetric peak observed around the Sn region appears to find its genesis in a symmetric quasifission component. On the other hand, the emergence of peaks around Pb in the decay of Z =112 , 114, and 116 nuclei signify the possible presence of asymmetric quasifission. Higher and broader asymmetric quasifission peaks are observed for *296116 and *292114 nuclei as compared to *286112 nucleus. Beside this, the total kinetic energy (TKE) distribution of the decay fragments is also explored by using different proximity potentials, such as Prox-77, Prox-88, and Prox-00. Prox-88 seems to perform better and the calculated TKE values find relatively better comparison at lower angular momentum states. The possible role of different radii of the decaying nuclei is also exercised to understand the TKE ¯ dynamics of 48Ca+238U,244Pu,248Cm reactions.

  13. Reflection-asymmetric rotor model of odd Aapprox. 219--229 nuclei

    SciTech Connect

    Leander, G.A.; Chen, Y.S.

    1988-06-01

    The low-energy spectroscopy of odd-A nuclei in the mass region Aapprox.219--229 is modeled by coupling states of a deformed shell model including octupole deformation to a reflection-asymmetric rotor core. Theory and experiment are compared for the nuclei in which data are available: /sup 219,221,223,225/Rn, /sup 221,223,225,227/Fr, /sup 219,221,223,225,227/Ra, /sup 219,223,225,227,229/Ac /sup 221,223,225,227,229/Th, and /sup 229/Pa. Overall agreement requires an octupole deformation ..beta../sub 3/approx.0.1. The results throughout the region are synthesized to evaluate the model.

  14. Study of the Process e+e- → K+K-π+π- With the CMD-3 Detector at the VEPP-2000 e+e- Collider

    NASA Astrophysics Data System (ADS)

    Akhmetshin, R. R.; Anisenkov, A. V.; Aulchenko, V. M.; Banzarov, V. S.; Barkov, L. M.; Bashtovoy, N. S.; Berkaev, D. E.; Bragin, A. V.; Eidelman, S. I.; Epifanov, D. A.; Epshteyn, L. B.; Erofeev, A. L.; Fedotovich, G. V.; Gayazov, S. E.; Grebenuk, A. A.; Grigoriev, D. N.; Gromov, E. M.; Ignatov, F. V.; Karpov, S. V.; Kazanin, V. F.; Khazin, B. I.; Kirpotin, A. N.; Koop, I. A.; Kovalenko, O. A.; Kozyrev, A. N.; Kozyrev, E. A.; Krokovny, P. P.; Kuzmenko, A. E.; Kuzmin, A. S.; Logashenko, I. B.; Lukin, P. A.; Lysenko, A. P.; Mikhailov, K. Yu.; Okhapkin, V. S.; Pestov, Yu. N.; Perevedentsev, E. A.; Popov, A. S.; Popov, Yu. S.; Razuvaev, G. P.; Rogovsky, Yu. A.; Romanov, A. L.; Ruban, A. A.; Ryskulov, N. M.; Ryzhenenkov, A. E.; Shebalin, V. E.; Shemyakin, D. N.; Shwartz, B. A.; Shwartz, D. B.; Sibidanov, A. L.; Shatunov, P. Yu.; Shatunov, Yu. M.; Solodov, E. P.; Titov, V. M.; Talyshev, A. A.; Vorobiov, A. I.; Yudin, Yu. V.; Zharinov, Yu. M.

    2014-12-01

    We report preliminary results on the measurement of the cross section of the process e+e- → K+K-π+π- in the c.m. energy range from 1.5 GeV to 2 GeV. It is shown that the cross section is dominated by the contributions of several intermediate states K+K-ρ, K*Kπ, ϕπ+π- and K*K*.

  15. International Symposium on Exotic Nuclei

    NASA Astrophysics Data System (ADS)

    Penionzhkevich, Yu. E.; Cherepanov, E. A.

    Methods of production of light exotic nuclei and study of their ptoperties -- Superheavy elements. Syhnthesis and properties -- Nuclear fission -- Nuclear reactions -- rare processes, decay and nuclear structure -- Experimental set-ups and future projects -- Radioactive beams. Production and research programmes -- Public relations.

  16. Proton Distribution in Heavy Nuclei

    DOE R&D Accomplishments Database

    Johnson, M. H; Teller, E.

    1953-11-13

    It is reasoned that, from considerations connected with beta-decay stability and Coulomb repulsion forces, a neutron excess is developed on the surface of heavy nuclei. Several consequences of this qualitative analysis in nucleon interactions are briefly noted. (K.S.)

  17. Chiral electroweak currents in nuclei

    DOE PAGES

    Riska, D. O.; Schiavilla, R.

    2017-01-10

    Here, the development of the chiral dynamics based description of nuclear electroweak currents is reviewed. Gerald E. (Gerry) Brown’s role in basing theoretical nuclear physics on chiral Lagrangians is emphasized. Illustrative examples of the successful description of electroweak observables of light nuclei obtained from chiral effective field theory are presented.

  18. Electromagnetic structure of light nuclei

    SciTech Connect

    Pastore, Saori

    Here, the present understanding of nuclear electromagnetic properties including electromagnetic moments, form factors and transitions in nuclei with A ≤ 10 is reviewed. Emphasis is on calculations based on nuclear Hamiltonians that include two- and three-nucleon realistic potentials, along with one- and two-body electromagnetic currents derived from a chiral effective field theory with pions and nucleons.

  19. Electromagnetic structure of light nuclei

    DOE PAGES

    Pastore, Saori

    2016-03-25

    Here, the present understanding of nuclear electromagnetic properties including electromagnetic moments, form factors and transitions in nuclei with A ≤ 10 is reviewed. Emphasis is on calculations based on nuclear Hamiltonians that include two- and three-nucleon realistic potentials, along with one- and two-body electromagnetic currents derived from a chiral effective field theory with pions and nucleons.

  20. Octupole correlation effects in nuclei

    SciTech Connect

    Chasman, R.R.

    1992-01-01

    Octupole correlation effects in nuclei are discussed from the point of view of many-body wavefunctions as well as mean-field methods. The light actinides, where octupole effects are largest, are considered in detail. Comparisons of theory and experiment are made for energy splittings of parity doublets; E1 transition matrix elements and one-nucleon transfer reactions.

  1. Octupole correlation effects in nuclei

    SciTech Connect

    Chasman, R.R.

    1992-08-01

    Octupole correlation effects in nuclei are discussed from the point of view of many-body wavefunctions as well as mean-field methods. The light actinides, where octupole effects are largest, are considered in detail. Comparisons of theory and experiment are made for energy splittings of parity doublets; E1 transition matrix elements and one-nucleon transfer reactions.

  2. Understanding nuclei: progress and challenges

    SciTech Connect

    Dean, D. J.

    2008-04-17

    Nuclear theory today aims for a comprehensive theoretical framework that can describe all nuclei. I discuss recent progress in this pursuit and the associated challenges as we move forward, paying particular attention to progress in the applications of coupled-cluster theory to the challenges.

  3. Nuclei and propeller cavitation inception

    SciTech Connect

    Gindroz, B.; Billet, M.L.

    1994-12-31

    Propeller cavitation inception tests were conducted in the Grand Tunnel Hydrodynamique (GTH) of the Bassin d`Essaid des Carenes. Both acoustic and visual cavitation inception were determined for leading-edge sheet, travelling bubble, and tip vortex. These data were obtained for specific water quality conditions. The water quality was determined from cavitation susceptibility meter measurements for degassed water (maximum liquid tension, few nuclei), low injection rate of microbubbles (medium liquid tension, low nuclei concentration), medium injection rate of microbubbles (medium liquid tension, high nuclei concentration) and high injection rate of microbubbles (minimum liquid tension, high nuclei concentration). Results clearly demonstrate a different influence of water quality for each type of cavitation. Little variation in cavitation inception index for a significant increase in liquid tension and microbubble size distribution was found for leading-edge sheet; however, tip vortex cavitation inception index decreased significantly for an increase in liquid tension. In addition, a dependency on event rate was determined for tip vortex cavitation inception.

  4. The {sup 3}He(e,e'p){sup 2}H and {sup 4}He(e,e'p){sup 3}H reactions at high momentum transfer

    SciTech Connect

    Ford, William P.; Schiavilla, Rocco; Van Orden, J. W.

    2014-03-01

    We present updated calculations for observables in the processes {sup 3}He(e,e'p){sup 2}H, {sup 4}He(e,e'p){sup 3}H and {sup 4}He(e-vector, e'p-vector){sup 3}H. This update entails the implementation of improved nucleon-nucleon (NN) amplitudes to describe final state interactions (FSI) within a Glauber approximation and includes full spin-isospin dependence in the profile operator. In addition, an optical potential, which has also been updated since previous work, is utilized to treat FSI for the {sup 4}He(e,e'p){sup 3}H and {sup 4}He(e-vector, e'p-vector){sup 3}H reactions. The calculations are compared with experimental data and show good agreement between theory and experiment. Comparisons are made between the various approximations in the Glauber treatment, including model dependence due to the NN scattering amplitudes, rescattering contributions, and spin dependence. We also analyze the validity of the Glauber approximation at the kinematics the data is available, by comparing to the results obtained with the optical potential.

  5. The influence of nuclear deformations on the exotic cluster decay half-lives

    NASA Astrophysics Data System (ADS)

    Soylu, A.; Bayrak, O.; Evlice, S.

    2015-04-01

    We systematically study the investigation of the influence of nuclear deformations of the cluster and daughter nuclei on the exotic cluster decay half-lives of heavy nuclei by the WKB method and the Bohr-Sommerfeld quantization condition. Even if the deformations of both cluster and daughter in the half-live values of cluster decays improve the results, considering the deformation of clusters is more efficient than the deformation of daughter for the heavy cluster decay half-live calculations. Moreover, taking into account of angle orientations of daughter and cluster provides a positive contributions to the results as well. The results would be useful for experimental researches in half-lives of exotic decays of some heavy nuclei and radium isotopes.

  6. Properties of true quaternary fission of nuclei with allowance for its multistep and sequential character

    SciTech Connect

    Kadmensky, S. G. Titova, L. V.; Bulychev, A. O.

    2015-07-15

    An analysis of basicmechanisms of binary and ternary fission of nuclei led to the conclusion that true ternary and quaternary fission of nuclei has a sequential two-step (three-step) character, where, at the first step, a fissile nucleus emits a third light particle (third and fourth light particles) under shakeup effects associated with a nonadiabatic character of its collective deformation motion, whereupon the residual nucleus undergoes fission to two fission fragments. Owing to this, the formulas derived earlier for the widths with respect to sequential two- and three-step decays of nuclei in constructing the theory of two-step twoproton decays and multistep decays in chains of genetically related nuclei could be used to describe the relative yields and angular and energy distributions of third and fourth light particles emitted in (α, α), (t, t), and (α, t) pairs upon the true quaternary spontaneous fission of {sup 252}Cf and thermal-neutron-induced fission of {sup 235}U and {sup 233}U target nuclei. Mechanisms that explain a sharp decrease in the yield of particles appearing second in time and entering into the composition of light-particle pairs that originate from true quaternary fission of nuclei in relation to the yields of analogous particles in true ternary fission of nuclei are proposed.

  7. Magnetic moments of neutron deficient yttrium nuclei

    SciTech Connect

    Berks; El Hajjaji, O.; Fahad, M.; Hassani, R.; Giroux, J.; Marest, G.; Marguier, G.; Stone, N.J.; Rikovska, J.; Green, V.R.; and others

    1987-12-10

    This paper describes recent low temperature nulcear orientation (LTNO) work on neutron deficient /sup 85m,86,86m/Y nuclei. Results are compared with experimental systematics of neighbouring nuclei and particle core coupling calculations.

  8. Nuclear structure of {sup 10}B studied with (e,e{prime}), ({pi},{pi}{prime}) and ({gamma},{pi}) reactions

    SciTech Connect

    Sato, T.; Odagawa, N.; Ohtsubo, H.; Lee, T.S.H.

    1994-05-01

    The authors studied nuclear structure of {sup 10}B using (e,e{prime}),({pi},{pi}{prime}) and ({gamma},{pi}) reactions under the distorted wave impulse approximation (DWIA). For this purpose the off-shell dependence of the amplitude was taken into account in the momentum space DWIA. They used the off-shell elementary amplitude of ({pi},{pi}) and ({gamma},{pi}) by the model of Nozawa, Blankleider and Lee. The first order core polarization effects were incorporated with the p-shell wave functions of Cohen and Kurath and Hauge and Maripuu. It was shown that the core-polarization effects greatly improve the agreement with the experimental data and that the simultaneous study of these reactions is useful to probe the spin structure of p-shell nuclei.

  9. Long Fission Times of Super-Heavy Compound Nuclei

    SciTech Connect

    Drouart, A.; Charvet, J. L.; Dayras, R.; Nalpas, L.; Volant, C.; Jacquet, D.

    2008-04-17

    The blocking technique in single crystals is a direct method to investigate the presence of long fission time components. With a lead beam impinging on a germanium single crystal, we tried to produce compound nuclei (CN) with atomic number Z = 114 at high excitation energy. Blocking patterns for reaction products are reconstructed with position sensitive detectors at 20 deg. relative to the beam direction. The Z and the energies of all products are measured with {delta}E-E telescopes of the 4{pi} INDRA array, so that all reaction channels are unambiguously identified. With this setup, we can reach long fission times (>10{sup -18} s) that can be associated with CN fissions. However, in contrast to previous experiments in which such long fission times could be measured for Z = 120 and 124, no hint of long lifetimes within our sensitivity limit for Z = 114 was observed, which may be due to the neutron deficiency of the formed isotopes.

  10. Properties of nuclei probed by laser light

    NASA Astrophysics Data System (ADS)

    Neugart, Rainer

    2017-03-01

    Viewing objects as small as atomic nuclei by visible light sounds quite unrealistic. However, nuclei usually appear as constituents of atoms whose excitations are indeed associated with the absorption and emission of light. Nuclei can thus interact with light via the atomic system as a whole.

  11. A microfluidic device for characterizing nuclear deformations.

    PubMed

    Hodgson, Andrew C; Verstreken, Christophe M; Fisher, Cynthia L; Keyser, Ulrich F; Pagliara, Stefano; Chalut, Kevin J

    2017-02-28

    Cell nuclei experience and respond to a wide range of forces, both in vivo and in vitro. In order to characterize the nuclear response to physical stress, we developed a microfluidic chip and used it to apply mechanical stress to live cells and measure their nuclear deformability. The device design is optimized for the detection of both nucleus and cytoplasm, which can then be conveniently quantified using a custom-written Matlab program. We measured nuclear sizes and strains of embryonic stem cells, for which we observed negative Poisson ratios in the nuclei. In addition, we were able to detect changes in the nuclear response after treatment with actin depolymerizing and chromatin decondensing agents. Finally, we showed that the device can be used for biologically relevant high-resolution confocal imaging of cells under compression. Thus, the device presented here allows for accurate physical phenotyping at high throughput and has the potential to be applied to a range of cell types.

  12. Correlations in Nuclei: Recent Progress on an Old Problem

    NASA Astrophysics Data System (ADS)

    Schiavilla, Rocco

    2007-10-01

    The two preeminent features of the nucleon-nucleon (NN) interaction are its short-range repulsion and intermediate- to long-range tensor character. These induce strong spatial-spin-isospin NN correlations, which leave their imprint on the structure of ground- and excited-state wave functions. In the present talk I will review how these features influence a variety of nuclear properties---from energy spectra of low-lying states to two-nucleon density distributions to nuclear response functions---as well as the experimental evidence in support of their presence. In particular, I will show [R. Schiavilla, R.B. Wiringa, S.C. Pieper, and J.Carlson, Phys. Rev. Lett. 98, 132501 (2007)] how tensor correlations impact the momentum distribution of np pairs in the ground state of nuclei and make it orders of magnitude larger than that of pp pairs for values of the relative momentum in the range (300--600) MeV/c and vanishing total momentum. This order-of-magnitude difference is seen in all nuclei considered, and has a universal character originating from the tensor components present in any realistic NN interaction. It should be easily observable in two-nucleon knock-out processes. Indeed, a preliminary analysis of (e,e^'np) and (e,e^'pp) reactions in ^12C finds [R. Subedi et al., in preparation] that the pp cross section is suppressed relative to the np by a factor ˜10 in kinematics close to back-to-back emission of the two nucleons.

  13. Theory of two-step two-proton decays of nuclei

    SciTech Connect

    Kadmensky, S. G. Ivankov, Yu. V.

    2014-12-15

    A general theory of many-body diagonal and nondiagonal one-proton decays of spherical and deformed nuclei is developed on the basis of an approach not employing R-matrix theory in describing deep-subbarrier alpha and one-proton decays of nuclei but relying on integral formulas for the widths with respect to these decays. With the aid of this theory and by means of a diagram technique, a formalism is developed for describing two-step two-proton decays of a (Z, A) parent nucleus, which proceed as two successive time-separated one-proton decays of the parent and intermediate [(Z − 1, A − 1)] nuclei, these decays being related by the Green’s function for the intermediate nucleus, G(Z − 1, A − 1). It is shown that, upon taking into account, in this Green’s function, intermediate-nucleus states that are on- and off-shell states for the decaying system, there arise, respectively, sequential and virtual two-proton decays of parent nuclei. Expressions for the widths with respect to sequential and virtual two-proton decays from the ground and excited states of spherical and deformed nuclei and for the angular and energy distributions of emitted protons are obtained.

  14. Dominant Modes in Light Nuclei - Ab Initio View of Emergent Symmetries

    NASA Astrophysics Data System (ADS)

    Draayer, J. P.; Dytrych, T.; Launey, K. D.; Dreyfuss, A. C.; Langr, D.

    2015-01-01

    An innovative symmetry-guided concept is discussed with a focus on emergent symmetry patterns in complex nuclei. In particular, the ab initio symmetry-adapted no-core shell model (SA-NCSM), which capitalizes on exact as well as partial symmetries that underpin the structure of nuclei, provides remarkable insight into how simple symmetry patterns emerge in the many-body nuclear dynamics from first principles. This ab initio view is complemented by a fully microscopic no-core symplectic shell-model framework (NCSpM), which, in turn, informs key features of the primary physics responsible for the emergent phenomena of large deformation and alpha-cluster substructures in studies of the challenging Hoyle state in Carbon-12 and enhanced collectivity in intermediate-mass nuclei. Furthermore, by recognizing that deformed configurations often dominate the low-energy regime, the SA-NCSM provides a strategy for determining the nature of bound states of nuclei in terms of a relatively small subspace of the symmetry-reorganized complete model space, which opens new domains of nuclei for ab initio investigations, namely, the intermediate-mass region, including isotopes of Ne, Mg, and Si.

  15. Search for the η'→e+e- decay with the SND detector

    NASA Astrophysics Data System (ADS)

    Achasov, M. N.; Aulchenko, V. M.; Barnyakov, A. Yu.; Beloborodov, K. I.; Berdyugin, A. V.; Berkaev, D. E.; Bogdanchikov, A. G.; Botov, A. A.; Dimova, T. V.; Druzhinin, V. P.; Golubev, V. B.; Kardapoltsev, L. V.; Kasaev, A. S.; Kharlamov, A. G.; Kirpotin, A. N.; Kovrizhin, D. P.; Koop, I. A.; Korol, A. A.; Koshuba, S. V.; Kupich, A. S.; Martin, K. A.; Muchnoi, N. Yu.; Obrazovsky, A. E.; Otboev, A. V.; Pakhtusova, E. V.; Senchenko, A. I.; Serednyakov, S. I.; Shatunov, P. Yu.; Shatunov, Yu. M.; Shtol, D. A.; Shwartz, D. B.; Silagadze, Z. K.; Surin, I. K.; Tikhonov, Yu. A.; Usov, Yu. V.; Vasiljev, A. V.; Zemlyansky, I. M.; SND Collaboration

    2015-05-01

    A search for the process e+e-→η' has been performed with the SND detector at the VEPP-2000 e+e- collider. The data were accumulated at the center-of-mass energy of 957.78 ±0.06 MeV with an integrated luminosity of about 2.9 pb-1 . For reconstruction of the η' meson, five decay chains have been used: η'→η π+π- followed by the η decays to γ γ and 3 π0 and η'→η π0π0 followed by the η decays to π+π-π0, γ γ , and 3 π0. As a result, the following upper limit has been set on the η' electronic width: Γη'→e+e-<0.0020 eV at the 90% confidence level.

  16. Spectroscopic study of light Lambda hypernuclei via the (e,e'K+) reaction

    SciTech Connect

    Okayasu, Yuichi

    2008-09-21

    Hypernuclear production through the (e,e'K+) reaction makes it possible to realize sub-MeV high-resolution spectroscopy of Λ hypernuclei thanks to the availability of high quality primary beams. It is in contrast to the (K-,L-) and (L+,K+) reactions which use secondary beams of pions and kaons. Even though hypernuclear cross sections are much smaller than those from meson beams, the (e,e'K+) reaction has advantageous features for Λ hypernuclear production. A goal of the present study is to further explore and establish (e,e'K+) spectroscopy as a tool to investigate Λ hypernuclei, succeeding the pioneering experiment JLab E89-009, which was successfully carried out previously.

  17. Radiative corrections for (e,e{prime}p) reactions at GeV energies

    SciTech Connect

    R. Ent; B. W. Filippone; N. C. R. Makins; R. G. Milner; T. G. O'Neill; D. A. Wasson

    2000-05-01

    A general framework for applying radiative corrections to (e,e{prime}p) coincidence reactions at GeV energies is presented, with special emphasis to higher-order Bremsstrahlung effects, radiation from the scattered hadron, and the validity of peaking approximations. The sensitivity to the assumptions made in practically applying radiative corrections to (e,e{prime}p) data is extensively discussed. The general framework is tested against experimental data of the {sup 1}H(e,e{prime}p) reaction at momentum transfer values larger than 1.0 (GeV/c){sup 2}, where radiative processes become a dominant source of uncertainty. The formulas presented here can easily be modified for any other electron-induced coincidence reaction.

  18. Status and prospects of precision analyses with e+e-→W+W-

    NASA Astrophysics Data System (ADS)

    Wells, James D.; Zhang, Zhengkang

    2016-02-01

    e+e-→W+W- is an integral part of the global precision analysis program which is becoming more relevant after the discovery of the Higgs boson. We analyze the current situation of precision calculations of inclusive e+e-→W+W- observables and study the prospects of incorporating them into the framework of global precision electroweak analyses in light of per-mil-level cross section measurements at proposed future facilities. We present expansion formulas for the observables, making the dependence on the inputs clear. Also, the calculation of new physics effects is demonstrated in the effective field theory framework for universal theories. We go beyond the triple-gauge-couplings parametrization and illustrate the complementarity of e+e-→W+W- and other precision data at the observables level.

  19. Study of e+e-→pp¯ via initial-state radiation at BABAR

    NASA Astrophysics Data System (ADS)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Dey, B.; Gary, J. W.; Long, O.; Vitug, G. M.; Campagnari, C.; Franco Sevilla, M.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Lockman, W. S.; Martinez, A. J.; Schumm, B. A.; Seiden, A.; Chao, D. S.; Cheng, C. H.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Morii, M.; Adametz, A.; Uwer, U.; Lacker, H. M.; Lueck, T.; Dauncey, P. D.; Mallik, U.; Chen, C.; Cochran, J.; Meyer, W. T.; Prell, S.; Rubin, A. E.; Gritsan, A. V.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Schune, M. H.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Prencipe, E.; Barlow, R. J.; Lafferty, G. D.; Behn, E.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Dallapiccola, C.; Cowan, R.; Dujmic, D.; Sciolla, G.; Cheaib, R.; Patel, P. M.; Robertson, S. H.; Biassoni, P.; Neri, N.; Palombo, F.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Simard, M.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Martinelli, M.; Raven, G.; Jessop, C. P.; LoSecco, J. M.; Honscheid, K.; Kass, R.; Brau, J.; Frey, R.; Sinev, N. B.; Strom, D.; Torrence, E.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Sitt, S.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Olsen, J.; Smith, A. J. S.; Anulli, F.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Bünger, C.; Grünberg, O.; Hartmann, T.; Leddig, T.; Voß, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Aston, D.; Bard, D. J.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Lindemann, D.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'vra, J.; Wagner, A. P.; Wang, W. F.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Ziegler, V.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Miyashita, T. S.; Puccio, E. M. T.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Spanier, S. M.; Ritchie, J. L.; Ruland, A. M.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; Gamba, D.; Zambito, S.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P.; Ahmed, H.; Albert, J.; Banerjee, Sw.; Bernlochner, F. U.; Choi, H. H. F.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.; Wu, S. L.

    2013-05-01

    The process e+e-→pp¯γ is studied using 469fb-1 of integrated luminosity collected with the BABAR detector at the SLAC National Accelerator Laboratory, at an e+e- center-of-mass energy of 10.6 GeV. From the analysis of the pp¯ invariant mass spectrum, the energy dependence of the cross section for e+e-→pp¯ is measured from threshold to 4.5 GeV. The energy dependence of the ratio of electric and magnetic form factors, |GE/GM|, and the asymmetry in the proton angular distribution are measured for pp¯ masses below 3 GeV. The branching fractions for the decays J/ψ→pp¯ and ψ(2S)→pp¯ are also determined.

  20. Physical processing of cometary nuclei

    NASA Technical Reports Server (NTRS)

    Weissman, Paul R.; Stern, S. Alan

    1989-01-01

    Cometary nuclei were formed far from the Sun in the colder regions of the solar nebula, and have been stored in distant orbits in the Oort cloud over most of the history of the solar system. It had been thought that this benign environment would preserve comets in close to their original pristine state. However, recent studies have identified a number of physical processes that have likely acted to modify cometary nuclei in a variety of significant ways. It is important to consider all of these possible processes, both in deciding on a site on the nucleus for collection of cometary samples, and in interpreting the results of analyses of returned cometary samples. Although it can no longer be said that comets are pristine samples of original solar nebula material, they are still the best obtainable samples of that unique period in the formation of the planetary system.

  1. Radio characteristics of galactic nuclei

    NASA Astrophysics Data System (ADS)

    Condon, J. J.

    1986-02-01

    Radio characteristics of galactic nuclei, providing such unique information as spectral data on source variability, and the long-term history of the central engine and its duration of activity and total energy, are reviewed. The compact radio source characteristics are complicated by orientation-dependent relativistic beaming and by refractive focusing in the interstellar medium. Incoherent synchrotron radiation is thought to be the emission mechanism, with the result that synchrotron self-absorption in compact sources hides the central engine from direct radio observation. However, the history revealed by the extended jets and lobes of radio galaxies and quasars favors a single massive object not supported by radiation pressure, either a spinar or a black hole, as the energy source in radio-galaxy nuclei.

  2. Beyond mean-field calculations for odd-mass nuclei.

    PubMed

    Bally, B; Avez, B; Bender, M; Heenen, P-H

    2014-10-17

    Beyond mean-field methods are very successful tools for the description of large-amplitude collective motion for even-even atomic nuclei. The state-of-the-art framework of these methods consists in a generator coordinate method based on angular-momentum and particle-number projected triaxially deformed Hartree-Fock-Bogoliubov (HFB) states. The extension of this scheme to odd-mass nuclei is a long-standing challenge. We present for the first time such an extension, where the generator coordinate space is built from self-consistently blocked one-quasiparticle HFB states. One of the key points for this success is that the same Skyrme interaction is used for the mean-field and the pairing channels, thus avoiding problems related to the violation of the Pauli principle. An application to ^{25}Mg illustrates the power of our method, as agreement with experiment is obtained for the spectrum, electromagnetic moments, and transition strengths, for both positive and negative parity states and without the necessity for effective charges or effective moments. Although the effective interaction still requires improvement, our study opens the way to systematically describe odd-A nuclei throughout the nuclear chart.

  3. e+e- collisions in the multi-TeV region

    SciTech Connect

    Ellis, J.

    1983-05-01

    A leading role in the elucidation of the Standard Model during the last few years has been played by e+e- colliding beam experiments. The e+e- discoveries have been made possible by the cleanliness of the experimental conditions and the ability to tune the centre-of-mass energy with precision to the desired value, thus avoiding less interesting background events. We expect history to repeat itself in the next step of elucidating physics beyond the Standard Model. Just as past e+e- machines such as SPEAR, DORIS and CESR have uncovered physics inaccessible to hadron-hadron collisions with a centre-of-mass energy several times higher, so we feel that future e+e- colliders will provide information that could not be duplicated by hadron colliders with much larger centre-of-mass energies. There is a general consensus that the next interesting energy range is likely to be in the TeV range. It is in this energy range that whatever physics provides and stabilizes the masses of the intermediate vector bosons must be revealed. Unravelling this mass generation mechanism takes us beyond the gauge principle of the Standard Model which has been so triumphantly vindicated in recent months. Therefore we discuss here the capabilities and attributes of an e+e- collider with at least 1 TeV energy per beam. We believe that by enabling an important new energy domain to be explored in detail, such an e+e- collider provides physics opportunities which cannot be paralled by hadron-hadron colliding rings with centre-of-mass energies several times higher. (WHK)

  4. Geometric symmetries in light nuclei

    NASA Astrophysics Data System (ADS)

    Bijker, R.

    2017-06-01

    The algebraic cluster model is is applied to study cluster states in the nuclei12C and16O. The observed level sequences can be understood in terms of the underlying discrete symmetry that characterizes the geometrical configuration of the α-particles, i.e. an equilateral triangle for12C, and a regular tetrahedron for16O. The structure of rotational bands provides a fingerprint of the underlying geometrical configuration of α-particles.

  5. Direct Reactions with Exotic Nuclei

    SciTech Connect

    Baur, G.; Typel, S.

    2005-10-14

    We discuss recent work on Coulomb dissociation and an effective-range theory of low-lying electromagnetic strength of halo nuclei. We propose to study Coulomb dissociation of a halo nucleus bound by a zero-range potential as a homework problem. We study the transition from stripping to bound and unbound states and point out in this context that the Trojan-Horse method is a suitable tool to investigate subthreshold resonances.

  6. Search for decays of B0-->e+ e-, B0-->mu+ mu-, B0-->e +/- mu-/+.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Couderc, F; Gaillard, J-M; Hicheur, A; Karyotakis, Y; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Shelkov, V G; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Cuhadar-Donszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Foulkes, S D; Gary, J W; Shen, B C; Wang, K; del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, Sh; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Lockman, W S; Nesom, G; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, K R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Cormack, C M; Harrison, P F; Lodovico, F Di; Mohanty, G B; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; LoSecco, J M; Gabriel, T A; Allmendinger, T; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; de la Vaissière, Ch; Del Buono, L; Hamon, O; John, M J J; Leruste, Ph; Malcles, J; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Anulli, F; Biasini, M; Peruzzi, I M; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martinez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Hamel de Monchenault, G; Kozanecki, W; Langer, M; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yèche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, G; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, P R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R; Roney, J M; Sobie, R J; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihalyi, A; Mohapatra, A K; Pan, Y; Prepost, R; Rubin, A E; Sekula, S J; Tan, P; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2005-06-10

    We present a search for the decays B0-->e+ e-, B0-->mu+ mu-, and B0-->e (+/-) mu (-/+) in data collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC B Factory. Using a data set of 111 fb(-1), we find no evidence for a signal in any of the three channels investigated and set the following branching fraction upper limits at the 90% confidence level: B(B0-->e+ e-) < 6.1 x 10(-8), B(B0-->mu+ mu-) < 8.3 x 10(-8), and B(B0-->e (+/-) mu (-/+) )<18 x 10(-8).

  7. Energy dependence of hadron polarization in e+e-→h X at high energies

    NASA Astrophysics Data System (ADS)

    Chen, Kai-bao; Yang, Wei-hua; Zhou, Ya-jin; Liang, Zuo-tang

    2017-02-01

    The longitudinal polarization of a hyperon in e+e- annihilation at high energies depends on the longitudinal polarization of the quark produced at the e+e- annihilation vertex, whereas the spin alignment of vector mesons is independent of it. They exhibit very different energy dependences. We use the longitudinal polarization of the Lambda hyperon and the spin alignment of K* as representative examples to present numerical results of energy dependences and demonstrate such distinct differences. We present the results at the leading twist with perturbative QCD evolutions of fragmentation functions at the leading order.

  8. H at a 300 GeV e e/sup /minus// collider

    SciTech Connect

    Grosse-Wiesmann, P.

    1988-12-01

    In the mass range from 80--180 GeV, no simple strategy for a detection of the H presently exists. Here we investigate the reaction e e/sup /minus// HZ at a center-of-mass energy of 300 GeV. We calculate the necessary luminosity to observe the H in the missing mass distribution of the Z l + l/sup /minus//. Possibilities for realizing an e e/sup /minus// collider with sufficient luminosity at such energies are investigated. In particular, the possibility of colliding an electron linear accelerator with a positron storage ring is discussed. 19 refs., 2 figs., 1 tab.

  9. Measurement of the π0→e+e-γ Dalitz decay at the Mainz Microtron

    NASA Astrophysics Data System (ADS)

    Adlarson, P.; Afzal, F.; Aguar-Bartolomé, P.; Ahmed, Z.; Akondi, C. S.; Annand, J. R. M.; Arends, H. J.; Bantawa, K.; Beck, R.; Berghäuser, H.; Biroth, M.; Borisov, N. S.; Braghieri, A.; Briscoe, W. J.; Cherepnya, S.; Cividini, F.; Collicott, C.; Costanza, S.; Denig, A.; Dieterle, M.; Downie, E. J.; Drexler, P.; Ferretti Bondy, M. I.; Fil'kov, L. V.; Gardner, S.; Garni, S.; Glazier, D. I.; Glowa, D.; Gradl, W.; Gurevich, G. M.; Hamilton, D. J.; Hornidge, D.; Huber, G. M.; Jude, T. C.; Käser, A.; Kashevarov, V. L.; Kay, S.; Keshelashvili, I.; Kondratiev, R.; Korolija, M.; Krusche, B.; Kulikov, V. V.; Lazarev, A.; Linturi, J.; Lisin, V.; Livingston, K.; MacGregor, I. J. D.; Macrae, R.; Manley, D. M.; Martel, P. P.; Martemianov, M.; McGeorge, J. C.; McNicoll, E. F.; Metag, V.; Middleton, D. G.; Miskimen, R.; Mornacchi, E.; Mullen, C.; Mushkarenkov, A.; Neganov, A.; Neiser, A.; Nikolaev, A.; Oberle, M.; Ostrick, M.; Ott, P.; Otte, P. B.; Paudyal, D.; Pedroni, P.; Polonski, A.; Prakhov, S.; Rajabi, A.; Robinson, J.; Ron, G.; Rosner, G.; Rostomyan, T.; Sfienti, C.; Sikora, M. H.; Sokhoyan, V.; Spieker, K.; Steffen, O.; Strakovsky, I. I.; Strandberg, B.; Strub, Th.; Supek, I.; Thiel, A.; Thiel, M.; Thomas, A.; Unverzagt, M.; Usov, Yu. A.; Wagner, S.; Walford, N.; Watts, D. P.; Werthmüller, D.; Wettig, J.; Witthauer, L.; Wolfes, M.; Zana, L. A.; A2 Collaboration at MAMI

    2017-02-01

    The Dalitz decay π0→e+e-γ has been measured in the γ p →π0p reaction with the A2 tagged-photon facility at the Mainz Microtron, MAMI. The value obtained for the slope parameter of the π0 electromagnetic transition form factor, aπ=0.030 ±0 .010tot , is in agreement with existing measurements of this decay and with recent theoretical calculations. The uncertainty obtained in the value of aπ is lower than in previous results based on the π0→e+e-γ decay.

  10. A Study of the Quasi-elastic (e,e'p) Reaction on {sup 12}C, {sup 56}Fe and {sup 197}Au

    SciTech Connect

    D. Dutta; D. van Westrum; et al

    2003-12-09

    We report the results from a systematic study of the quasi-elastic (e,e'p) reaction on {sup 12}C, {sup 56}Fe and {sup 197}Au performed at Jefferson Lab. We have measured nuclear transparency and extracted spectral functions (corrected for radiation) over a Q{sup 2} range of 0.64 - 3.25 (GeV/c){sup 2} for all three nuclei. In addition we have extracted separated longitudinal and transverse spectral functions at Q{sup 2} of 0.64 and 1.8 (GeV/c){sup 2} for these three nuclei (except for {sup 197}Au at the higher Q{sup 2}). The spectral functions are compared to a number of theoretical calculations. The measured spectral functions differ in detail but not in overall shape from most of the theoretical models. In all three targets the measured spectral functions show considerable excess transverse strength at Q{sup 2} = 0.64 (GeV/c){sup 2}, which is much reduced at 1.8 (GeV/c){sup 2}.

  11. Emergent symmetries in atomic nuclei from first principles

    NASA Astrophysics Data System (ADS)

    Launey, K. D.; Dreyfuss, A. C.; Baker, R. B.; Draayer, J. P.; Dytrych, T.

    2015-04-01

    An innovative symmetry-guided approach and its applications to light and intermediate-mass nuclei is discussed. This approach, with Sp(3, R) the underpinning group, is based on our recent remarkable finding, namely, we have identified the symplectic Sp(3,R) as an approximate symmetry for low-energy nuclear dynamics. This study presents the results of two complementary studies, one that utilizes realistic nucleon-nucleon interactions and unveils symmetries inherent to nuclear dynamics from first principles (or ab initio), and another study, which selects important components of the nuclear interaction to explain the primary physics responsible for emergent phenomena, such as enhanced collectivity and alpha clusters. In particular, within this symmetry-guided framework, ab initio applications of the theory to light nuclei reveal the emergence of a simple orderly pattern from first principles. This provides a strategy for determining the nature of bound states of nuclei in terms of a relatively small fraction of the complete shell-model space, which, in turn, can be used to explore ultra-large model spaces for a description of alpha-cluster and highly deformed structures together with associated rotations. We find that by using only a fraction of the model space extended far beyond current no-core shell-model limits and a long-range interaction that respects the symmetries in play, the outcome reproduces characteristic features of the low-lying 0+ states in 12C (including the elusive Hoyle state of importance to astrophysics) and agrees with ab initio results in smaller spaces. For these states, we offer a novel perspective emerging out of no-core shell-model considerations, including a discussion of associated nuclear deformation, matter radii, and density distribution. The framework we find is also extensible beyond 12C, namely, to the low-lying 0+ states of 8Be as well as the ground-state rotational band of Ne, Mg, and Si isotopes.

  12. Signature effects in 2qp bands of doubly even rare-earth nuclei

    NASA Astrophysics Data System (ADS)

    Kalra, Kawalpreet; Goel, Alpana; Jain, A. K.

    2016-12-01

    The two-quasiparticle rotational bands in deformed doubly even nuclei in the rare-earth region have been studied in detail. A number of interesting features like odd-even staggering and signature inversion have been observed. The phenomenon of signature inversion/reversal is observed experimentally in 162 66Dy, 170 0Yb and 170 74W in even-even nuclei. Two quasiparticle plus rotor model (TQPRM) calculations are carried out to explain the reverse pattern of signature in 170 74W for the rotational band having configuration {(h_{11/2})p ⊗ (d_{5/2})p}.

  13. Time-dependent Hartree-Fock Study of Octupole Vibrations in doubly magic nuclei

    NASA Astrophysics Data System (ADS)

    Simenel, C.; Buete, J.; Vo-Phuoc, K.

    2016-09-01

    Octupole vibrations are studied in some doubly magic nuclei using the time-dependent Hartree-Fock (TDHF) theory with a Skyrme energy density functional. Through the use of the linear response theory, the energies and transition amplitudes of the low-lying vibrational modes for each of the nuclei were determined. Energies were found to be close to experimental results. However, transition amplitudes, quantified by the deformation parameter β3, are underestimated by TDHF. A comparison with single-particle excitations on the Hartree-Fock ground-state shows that the collective octupole vibrations have their energy lowered due to attractive RPA residual interaction.

  14. Evolution of collectivity in neutron-rich nuclei in the Sn132 region

    NASA Astrophysics Data System (ADS)

    Kshetri, Ritesh; Sarkar, M. Saha; Sarkar, S.

    2006-09-01

    Motivated by the observed regularity in the energy spectra and the structure of the shell model wave functions for the levels of Te137 and I137, a few weakly and moderately deformed neutron-rich odd-A nuclei above the doubly magic nucleus Sn132 were studied using the particle rotor model (PRM). The calculated energy spectra and branching ratios agree reasonably well with the most recent experimental data. In a few cases ambiguity in level ordering was resolved and spin-parities were assigned to the levels. Observed octupole correlation in some of these nuclei is discussed in the light of the present results.

  15. Recent results at ultrahigh spin: Terminating states and beyond in mass 160 rare-earth nuclei

    DOE PAGES

    Paul, E. S.; Rees, J. M.; Hampson, P.; ...

    2015-01-01

    A classic region of band termination at high spin occurs in rare-earth nuclei with around ten valence nucleons above the 146Gd closed core. The results are presented here for such non-collective oblate (γ = 60°) terminating states in odd-Z 155Ho, odd–odd 156Ho, and even–even 156Er, where they are compared with neighboring nuclei. In addition to these particularly favoured states, the occurrence of collective triaxial strongly deformed (TSD) bands, bypassing the terminating states and extending to over 65ℏ, is reviewed.

  16. Recent results at ultrahigh spin: Terminating states and beyond in mass 160 rare-earth nuclei

    SciTech Connect

    Paul, E. S.; Rees, J. M.; Hampson, P.; Riley, M. A.; Simpson, J.; Ayangeakaa, A. D.; Baron, J. S.; Carpenter, M. P.; Chiara, C. J.; Garg, U.; Hartley, D. J.; Hoffman, C. R.; Janssens, R. V. F.; Kondev, F. G.; Lauritsen, T.; Mason, P. J. R.; Matta, J.; Miller, S. L.; Nolan, P. J.; Ollier, J.; Petri, M.; Radford, D. C.; Revill, J. P.; Wang, X.; Zhu, S.; Ragnarsson, I.

    2015-01-01

    A classic region of band termination at high spin occurs in rare-earth nuclei with around ten valence nucleons above the 146Gd closed core. The results are presented here for such non-collective oblate (γ = 60°) terminating states in odd-Z 155Ho, odd–odd 156Ho, and even–even 156Er, where they are compared with neighboring nuclei. In addition to these particularly favoured states, the occurrence of collective triaxial strongly deformed (TSD) bands, bypassing the terminating states and extending to over 65ℏ, is reviewed.

  17. Saddle point shapes of nuclei

    SciTech Connect

    Poenaru, D. N.; Plonski, I. H.; Greiner, W.

    2007-04-23

    Very 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.

  18. Analysis of the Neutron Electric Form Factor at Q2 = 1.4 GeV2 using the reaction 3 H->e (e-> ,e' n) pp

    NASA Astrophysics Data System (ADS)

    Obrecht, Richard; Super Bigbite Collaboration

    2016-09-01

    The Jefferson Lab Hall A experiment E02-013 extracted the neutron electric form factor GEn by measuring the beam-target asymmetry in quasi-elastically scattering of longitudinally polarized electrons from a polarized 3He target via the semi-exclusive reaction3 H->e (e-> ,e' n) pp . The experiment measured the electric form factor at a spacelike four-momentum transfer squared Q2 = 1.4, 1.7, 2.7, and 3.4 GeV2, but only the latter three points were published by S. Riordan et al. (Phys. Rev. Lett. 105, 262302). The goal of this talk is to present the analysis chain necessary to extract the form factor from a neutron asymmetry that arises by periodically changing the sign of the beam helicity. The analysis includes selecting quasi-elastic events in a high noise environment, and correcting for various factors that dilute the signal such as false proton asymmetries and final state interactions within the target. Jefferson Lab Hall A.

  19. Measurement of double polarized asymmetries in quasi-elastic processes ${}^3\\vec{He}(\\vec{e},e' d)$ and ${}^3\\vec{He}(\\vec{e},e' p)$

    SciTech Connect

    Mihovilovic, Miha

    2012-01-01

    This thesis is dedicated to a study of a spin-isospin structure of the polarized 3He. First, an introduction to the spin structure of 3He is given, followed by a brief overview of past experiments. The main focus of the thesis is the E05-102 experiment at Jefferson Lab, in which the reactions ${}^3\\vec{He}(\\vec{e},e' d)$ and ${}^3\\vec{He}(\\vec{e},e' p)$ in the quasi-elastic region were studied. The purpose of this experiment was to better understand the effects of the S'- and D-state contributions to the 3He ground-state wave-functions by a precise measurement of beam-target asymmetries Ax and Az in the range of recoil momenta from 0 to about 300 MeV/c. The experimental equipment utilized in these measurements is described, with special attention devoted to the calibration of the hadron spectrometer, BigBite. Results on the measured asymmetries are presented, together with first attempts at their comparison to the state-of-the art Faddeev calculations. The remaining open problems and challenges for future work are also discussed.

  20. Deformation properties of lead isotopes

    SciTech Connect

    Tolokonnikov, S. V.; Borzov, I. N.; Lutostansky, Yu. S.; Saperstein, E. E.

    2016-01-15

    The deformation properties of a long lead isotopic chain up to the neutron drip line are analyzed on the basis of the energy density functional (EDF) in the FaNDF{sup 0} Fayans form. The question of whether the ground state of neutron-deficient lead isotopes can have a stable deformation is studied in detail. The prediction of this deformation is contained in the results obtained on the basis of the HFB-17 and HFB-27 Skyrme EDF versions and reported on Internet. The present analysis reveals that this is at odds with experimental data on charge radii and magnetic moments of odd lead isotopes. The Fayans EDF version predicts a spherical ground state for all light lead isotopes, but some of them (for example, {sup 180}Pb and {sup 184}Pb) prove to be very soft—that is, close to the point of a phase transition to a deformed state. Also, the results obtained in our present study are compared with the predictions of some other Skyrme EDF versions, including SKM*, SLy4, SLy6, and UNE1. By and large, their predictions are closer to the results arising upon the application of the Fayans functional. For example, the SLy4 functional predicts, in just the same way as the FaNDF{sup 0} functional, a spherical shape for all nuclei of this region. The remaining three Skyrme EDF versions lead to a deformation of some light lead isotopes, but their number is substantially smaller than that in the case of the HFB-17 and HFB-27 functionals. Moreover, the respective deformation energy is substantially lower, which gives grounds to hope for the restoration of a spherical shape upon going beyond the mean-field approximation, which we use here. Also, the deformation properties of neutron-rich lead isotopes are studied up to the neutron drip line. Here, the results obtained with the FaNDF{sup 0} functional are compared with the predictions of the HFB-17, HFB-27, SKM*, and SLy4 Skyrme EDF versions. All of the EDF versions considered here predict the existence of a region where neutron

  1. Deformations in VLBI antennas

    NASA Technical Reports Server (NTRS)

    Clark, T. A.; Thomsen, P.

    1988-01-01

    A study is presented of deformations in antennas with the emphasis on their influence on VLBI measurements. The GIFTS structural analysis program has been used to model the VLBI antenna in Fairbanks (Alaska). The report identifies key deformations and studies the effect of gravity, wind, and temperature. Estimates of expected deformations are given.

  2. P.E.E.R.: Dickinson College's Summer Gown/Town Program for Elementary Children.

    ERIC Educational Resources Information Center

    Boytim, James A.

    Dickinson College has operated the Program for Education, Enrichment, and Recreation (P.E.E.R.) for 66 children ages 7-11 since 1968. The program operates for an 8-week summer session for elementary school children who may benefit from a supervised, structured, small group experience. Swimming instruction is provided along with other sports, arts…

  3. Evidence of Two Resonant Structures in e+e-→π+π-hc

    NASA Astrophysics Data System (ADS)

    Ablikim, M.; Achasov, M. N.; Ahmed, S.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Bakina, O.; Baldini Ferroli, R.; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Berger, N.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chai, J.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; de Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Dou, Z. L.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Farinelli, R.; Fava, L.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. L.; Gao, Y.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, L.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, R. P.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S.; Hao, X. Q.; Harris, F. A.; He, K. L.; Heinsius, F. H.; Held, T.; Heng, Y. K.; Holtmann, T.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang, X. Z.; Huang, Z. L.; Hussain, T.; Ikegami Andersson, W.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. W.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kiese, P.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kupsc, A.; Kühn, W.; Lange, J. S.; Lara, M.; Larin, P.; Lavezzi, L.; Leithoff, H.; Leng, C.; Li, C.; Li, Cheng; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, H. J.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, Q. Y.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, Y. B.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B.; Liu, B. J.; Liu, C. X.; Liu, D.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Y. Y.; Liu, Z. A.; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, M. M.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Ma, Y. M.; Maas, F. E.; Maggiora, M.; Malik, Q. A.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Mezzadri, G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales Morales, C.; Muchnoi, N. Yu.; Muramatsu, H.; Musiol, P.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pan, Y.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Prasad, V.; Qi, H. R.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ripka, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Sarantsev, A.; Savrié, M.; Schnier, C.; Schoenning, K.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. H.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, W.; Wang, W. P.; Wang, X. F.; Wang, Y.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, L. J.; Wu, Z.; Xia, L.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Z. J.; Xie, Y. G.; Xie, Yuehong; Xiu, Q. L.; Xu, G. F.; Xu, J. J.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yin, J. H.; You, Z. Y.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zeng, Y.; Zeng, Z.; Zhang, B. X.; Zhang, B. Y.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. Q.; Zhang, X. Y.; Zhang, Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. N.; Zhang, Y. T.; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zotti, L.; Zou, B. S.; Zou, J. H.; Besiii Collaboration

    2017-03-01

    The cross sections of e+e-→π+π-hc at center-of-mass energies from 3.896 to 4.600 GeV are measured using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The cross sections are found to be of the same order of magnitude as those of e+e-→π+π-J /ψ and e+e-→π+π-ψ (2 S ), but the line shape is inconsistent with the Y states observed in the latter two modes. Two structures are observed in the e+e-→π+π-hc cross sections around 4.22 and 4.39 GeV /c2 , which we call Y (4220 ) and Y (4390 ), respectively. A fit with a coherent sum of two Breit-Wigner functions results in a mass of (4218. 4-4.5+5.5±0.9 ) MeV /c2 and a width of (66. 0-8.3+12.3±0.4 ) MeV for the Y (4220 ), and a mass of (4391. 5-6.8+6.3±1.0 ) MeV /c2 and a width of (139. 5-20.6+16.2±0.6 ) MeV for the Y (4390 ), where the first uncertainties are statistical and the second ones systematic. The statistical significance of Y (4220 ) and Y (4390 ) is 10 σ over one structure assumption.

  4. A Stylistic Study on the Linguistic Deviations in E. E. Cummings' Poetry

    ERIC Educational Resources Information Center

    Li, Xin; Shi, Mengchen

    2015-01-01

    Regarded as the pioneer of experimental poetry, E. E. Cummings' unconventional treatment of poetic language has reached an unprecedented acme, which has intrigued and baffled numerous scholars, researchers and readers alike. Nevertheless, the very existence of poetry, like other types of literary texts, demonstrates the significance and value of…

  5. A consistent Analysis of (e,e'p) Reactions through the Nonlocal Dispersive Optical Model

    NASA Astrophysics Data System (ADS)

    Atkinson, Mack; Mahzoon, Mohammadhossein; Dickhoff, Willem; Charity, Robert

    2017-01-01

    A nonlocal dispersive optical model (DOM) analysis of the 40Ca(e,e'p)39K reaction has been implemented. The real and imaginary potentials are constrained by fitting to elastic-scattering data, total and reaction cross sections, energy level information, and the charge density of 40Ca. The nonlocality of these potentials permits a proper dispersive self-energy, which accurately describes both positive and negative energy observables. Previous 40Ca(e,e'p)39K calculations, using local non-dispersive potentials employed in a distorted-wave impulse approximation (DWIA), provided the accepted values of 0.65 and 0.5 for the spectroscopic factors of the 0d3/2 and 1s1/2 orbitals, respectively. These orbitals have well defined spectroscopic factors which can be calculated directly from the DOM self-energy, corresponding to 0.76 and 0.74, respectively. The 40Ca(e,e'p)39K cross sections calculated using the DOM self-energy is in good agreement with the experimental cross sections. These results suggest that a proper description of the (e,e'p) reaction is indeed obtained through the DWIA only by using non-local dispersive optical potentials that simultaneously describe the overlap function and outgoing wavefunction of the proton. NSF

  6. Probing the Higgs with angular observables at future e+e- colliders

    NASA Astrophysics Data System (ADS)

    Liu, Zhen

    2016-10-01

    I summarize our recent works on using differential observables to explore the physics potential of future e+e- colliders in the framework of Higgs effective field theory. This proceeding is based upon Refs. 1 and 2. We study angular observables in the e+e-→ ZHℓ+ℓ-bb¯ channel at future circular e+e- colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy s = 240 GeV and 5 (30) ab-1 integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for the Higgsstrahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of constraining the “blind spot” in indirect limits on supersymmetric scalar top partners. We also discuss the possibility of using ZZ-fusion at e+e- machines at different energies to probe new operators.

  7. Production of actinide nuclei by multi-nucleon transfer

    SciTech Connect

    Lauritsen, T.; Ahmad, I.; Carpenter, M.P.

    1995-08-01

    Multi-nucleon transfers have increasingly allowed us to reach parts of the nuclear chart where regular compound nuclear reactions are prohibited. The interesting region of Ra and Rn, where a rich tapestry of nuclear structure manifests itself, is now accessible using this technique of deep inelastic scattering. In particular, these nuclei are predicted to lie at the onset of octupole deformation and the region is rich in examples of shape coexistence. There are several theoretical predictions of nuclear structure of these nuclei that have not been experimentally tested. Moreover, there is serious disagreement among these theories. We used a beam of {sup 136}Xe at 720 MeV from ATLAS on a target of {sup 232}Th to produce a range of Rn isotopes, with a mass from 220 to 224, and Ra isotopes with masses greater than 222. The beam energy, target and beam were selected carefully to enhance the cross-section for production of these nuclei and reduce the Doppler broadening of the gamma rays that were observed in the Argonne Notre Dame gamma-ray facility. The 12 germanium detectors of this array allowed the observation of gamma-gamma coincidences. The inner ball of 50 BGO detectors allowed us to record the multiplicity and sum-energy information for each event. The latter should permit us to determine the entry region in the products of the transfer reaction. We had four successful days of beam-time, when we collected in excess of 8 x 10{sup 7} events. Data analysis is in progress at the University of Liverpool. A complete set of spectroscopic information on the yrast structure of the many nuclei produced in this reaction is being extracted.

  8. The Peculiarities of the Production and Decay of Superheavy Nuclei

    NASA Astrophysics Data System (ADS)

    Itkis, M. G.; Beghini, S.; Behera, B. R.; Bogachev, A. A.; Bouchat, V.; Corradi, L.; Dorvaux, O.; Fioretto, E.; Hanappe, F.; Itkis, I. M.; Jandel, M.; Kliman, J.; Knyazheva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Krupa, L.; Latina, A.; Materna, T.; Montagnoli, G.; Oganessian, Yu. Ts.; Pokrovsky, I. V.; Prokhorova, E. V.; Rowley, N.; Rusanov, A. Ya.; Sagaidak, R. N.; Scarlassara, F.; Schmitt, C.; Stefanini, A. M.; Stuttge, L.; Szilner, S.; Trotta, M.

    2006-08-01

    The interest in the study of the fission process of superheavy nuclei mainly deals with the opportunity to obtain information about the cross-section of the compound nucleus (CN) formation at excitation energies E*≈15-30 MeV. It allows one to estimate the survival probability of the superheavy composite system after evaporation of 1-3 neutrons, i.e. in "cold" or "warm" fusion reactions. However, in order to solve this problem deeper understanding of the coalescence processes between colliding nuclei, the competition between fusion-fission and quasi-fission processes is needed. The characteristics of both processes, their manifestation in the experimental observables and the relative contribution to the capture cross-section in dependence on the excitation energies, reaction entrance channel etc were investigated for a wide range of target-projectile combinations. Results of the experiments devoted to the study of the fusion-fission and quasi-fission processes in the reactions of the formation of the superheavy nuclei with Z = 102-122 are presented. The heavy ions 26Mg, 48Ca, 50Ti, 58Fe and 64Ni were used as projectiles. The choice of the reactions with 48Ca and actinide-targets was inspired by the experiments on the production of the isotopes 283112, 289114 and 283116 in Dubna using the same reactions. The 50Ti, 58Fe and 64Ni projectiles were chosen since the corresponding projectile-target combinations lead to the synthesis of even heavier elements. The experiments were carried out at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Russia) and the XTU Tandem accelerator of the National Laboratory of Legnaro (LNL, Italy) using the time-of-flight spectrometer of fission fragments CORSET. The role of the shell effects, the influence of the entrance channel asymmetry and the deformations of colliding nuclei on the mechanism of the fusion-fission and the competitive process of quasi-fission are discussed. The recent results on synthesis of

  9. Study of Complete Fusion Reactions Leading to the Production of Heavy and Superheavy Nuclei

    SciTech Connect

    Roman N. Sagaidak

    1999-12-31

    Cross section values for heavy evaporation residues (ER) produced in complete fusion reactions induced by heavy ions on spherical and deformed target nuclei are analyzed in the framework of barrier penetration and statistical model approximations. For the reactions leading to Rn-Pa nuclei, a strong influence of the entrance channel on the measured cross section values is observed for nearly symmetric projectile-target combinations. In order to reproduce the observed excitation functions in such combinations we had to introduce the quantity of fusion probability. Considering the asymmetric reactions leading to the heaviest nuclei we also had to use the fusion probability to reproduce the cross section values obtained for cold fusion reactions induced by {sup 50}Ti and heavier projectiles on the Pb and Bi target nuclei, and also the values obtained for hot fusion reactions induced by {sup 34}S on actinide target nuclei. The scaling of fusion probabilities derived for both the reactions allowed us to predict the values of cross sections for superheavy elements (SHE) produced in the {sup 48}Ca induced reactions on actinide target nuclei and in the cold fusion reactions induced by the Zn and heavier projectiles.

  10. Study of complete fusion reactions leading to the production of heavy and superheavy nuclei

    SciTech Connect

    Sagaidak, Roman N.

    1999-11-16

    Cross section values for heavy evaporation residues (ER) produced in complete fusion reactions induced by heavy ions on spherical and deformed target nuclei are analyzed in the framework of barrier penetration and statistical model approximations. For the reactions leading to Rn-Pa nuclei, a strong influence of the entrance channel on the measured cross section values is observed for nearly symmetric projectile-target combinations. In order to reproduce the observed excitation functions in such combinations we had to introduce the quantity of fusion probability. Considering the asymmetric reactions leading to the heaviest nuclei we also had to use the fusion probability to reproduce the cross section values obtained for cold fusion reactions induced by {sup 50}Ti and heavier projectiles on the Pb and Bi target nuclei, and also the values obtained for hot fusion reactions induced by {sup 34}S on actinide target nuclei. The scaling of fusion probabilities derived for both the reactions allowed us to predict the values of cross sections for superheavy elements (SHE) produced in the {sup 48}Ca induced reactions on actinide target nuclei and in the cold fusion reactions induced by the Zn and heavier projectiles.

  11. The shell model—simplicity from complexity: some of my best nuclei are spherical

    NASA Astrophysics Data System (ADS)

    Talmi, Igal

    2017-08-01

    This article presents shell model applications to spherical nuclei with strong emphasis on semi-magic ones. A successful description of their low lying levels is obtained by applying to them the spherical shell model. These spherical nuclei are rather different from nuclei which exhibit collective phenomena, like rotational spectra. In the present article, several applications of the shell model to nuclei are presented. Only simple cases are considered which do not involve complicated calculations. These cases are sufficient to demonstrate the power of the shell model and to find the important ingredients of the mutual interactions of nucleons. The latter are limited to two-body interactions and it seems that they are the important ones in determination of the structure of nuclei. The interaction which should be used in the shell model (effective interaction) is a highly renormalized version of the bare interaction, between free nucleons. In the absence of a reliable many-body theory of the nucleus, matrix elements of the effective interaction are determined from energies of actual nuclei. General features of these are discussed, with particular attention to matrix elements which lead to nuclear deformation and rotational spectra.

  12. Correlations between neutrons and protons near the Fermi surface and Qα of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Wang, Ning; Liu, Min; Wu, Xizhen; Meng, Jie

    2016-01-01

    The shell corrections and shell gaps in nuclei are systematically studied with the latest Weizsäcker-Skyrme (WS4) mass model. We find that most of asymmetric nuclei with (sub)shell closures locate along the shell stability line (SSL), N =1.37 Z +13.5 , which might be due to a strong correlation between neutrons and protons near the Fermi surface. The double magicity of nuclei 46Si and 78Ni is predicted according to the corresponding shell gaps, shell corrections, and nuclear deformations. The unmeasured superheavy nuclei, 296118 and 298120, with relatively large shell gaps and shell corrections, also locate along the SSL, whereas the traditional magic nucleus 298Fl evidently deviates from the line. The α -decay energies of superheavy nuclei with Z =113 -126 are simultaneously investigated by using the WS4 model together with the radial basis function corrections. For superheavy nuclei with large shell corrections, the smallest α -decay energy for elements Z =116 , 117, and 118 in their isotope chains locates at N =178 rather than 184.

  13. Theoretical Interpretation of Pass 8 Fermi-LAT e + + e - Data

    NASA Astrophysics Data System (ADS)

    Di Mauro, M.; Manconi, S.; Vittino, A.; Donato, F.; Fornengo, N.; Baldini, L.; Bonino, R.; Di Lalla, N.; Latronico, L.; Maldera, S.; Manfreda, A.; Negro, M.; Pesce-Rollins, M.; Sgrò, C.; Spada, F.

    2017-08-01

    The flux of positrons and electrons (e + + e -) has been measured by the Fermi Large Area Telescope (LAT) in the energy range between 7 GeV and 2 TeV. We discuss a number of interpretations of Pass 8 Fermi-LAT e + + e - spectrum, combining electron and positron emission from supernova remnants (SNRs) and pulsar wind nebulae (PWNe), or produced by the collision of cosmic rays (CRs) with the interstellar medium. We find that the Fermi-LAT spectrum is compatible with the sum of electrons from a smooth SNR population, positrons from cataloged PWNe, and a secondary component. If we include in our analysis constraints from the AMS-02 positron spectrum, we obtain a slightly worse fit to the e + + e - Fermi-LAT spectrum, depending on the propagation model. As an additional scenario, we replace the smooth SNR component within 0.7 kpc with the individual sources found in Green’s catalog of Galactic SNRs. We find that separate consideration of far and near sources helps to reproduce the e + + e - Fermi-LAT spectrum. However, we show that the fit degrades when the radio constraints on the positron emission from Vela SNR (which is the main contributor at high energies) are taken into account. We find that a break in the power-law injection spectrum at about 100 GeV can also reproduce the measured e + + e - spectrum and, among the CR propagation models that we consider, no reasonable break of the power-law dependence of the diffusion coefficient can modify the electron flux enough to reproduce the observed shape.

  14. Deformable Nanolaminate Optics

    SciTech Connect

    Olivier, S S; Papavasiliou, A P; Barbee, T W; Miles, R R; Walton, C C; Cohn, M B; Chang, K

    2006-05-12

    We are developing a new class of deformable optic based on electrostatic actuation of nanolaminate foils. These foils are engineered at the atomic level to provide optimal opto-mechanical properties, including surface quality, strength and stiffness, for a wide range of deformable optics. We are combining these foils, developed at Lawrence Livermore National Laboratory (LLNL), with commercial metal processing techniques to produce prototype deformable optics with aperture sizes up to 10 cm and actuator spacing from 1 mm to 1 cm and with a range of surface deformation designed to be as much as 10 microns. The existing capability for producing nanolaminate foils at LLNL, coupled with the commercial metal processing techniques being used, enable the potential production of these deformable optics with aperture sizes of over 1 m, and much larger deformable optics could potentially be produced by tiling multiple deformable segments. In addition, based on the fabrication processes being used, deformable nanolaminate optics could potentially be produced with areal densities of less than 1 kg per square m for applications in which lightweight deformable optics are desirable, and deformable nanolaminate optics could potentially be fabricated with intrinsically curved surfaces, including aspheric shapes. We will describe the basic principles of these devices, and we will present details of the design, fabrication and characterization of the prototype deformable nanolaminate optics that have been developed to date. We will also discuss the possibilities for future work on scaling these devices to larger sizes and developing both devices with lower areal densities and devices with curved surfaces.

  15. Ground states of larger nuclei

    SciTech Connect

    Pieper, S.C.; Wiringa, R.B.; Pandharipande, V.R.

    1995-08-01

    The methods used for the few-body nuclei require operations on the complete spin-isospin vector; the size of this vector makes such methods impractical for nuclei with A > 8. During the last few years we developed cluster expansion methods that do not require operations on the complete vector. We use the same Hamiltonians as for the few-body nuclei and variational wave functions of form similar to the few-body wave functions. The cluster expansions are made for the noncentral parts of the wave functions and for the operators whose expectation values are being evaluated. The central pair correlations in the wave functions are treated exactly and this requires the evaluation of 3A-dimensional integrals which are done with Monte Carlo techniques. Most of our effort was on {sup 16}O, other p-shell nuclei, and {sup 40}Ca. In 1993 the Mathematics and Computer Science Division acquired a 128-processor IBM SP which has a theoretical peak speed of 16 Gigaflops (GFLOPS). We converted our program to run on this machine. Because of the large memory on each node of the SP, it was easy to convert the program to parallel form with very low communication overhead. Considerably more effort was needed to restructure the program from one oriented towards long vectors for the Cray computers at NERSC to one that makes efficient use of the cache of the RS6000 architecture. The SP made possible complete five-body cluster calculations of {sup 16}O for the first time; previously we could only do four-body cluster calculations. These calculations show that the expectation value of the two-body potential is converging less rapidly than we had thought, while that of the three-body potential is more rapidly convergent; the net result is no significant change to our predicted binding energy for {sup 16}O using the new Argonne v{sub 18} potential and the Urbana IX three-nucleon potential. This result is in good agreement with experiment.

  16. Breakup Densities of Hot Nuclei

    NASA Astrophysics Data System (ADS)

    Viola, V. E.; Kwiatkowski, K.; Natowitz, J. B.; Yennello, S. J.

    2004-09-01

    Breakup densities of hot 197Au-like residues have been deduced from the systematic trends of Coulomb parameters required to fit intermediate-mass-fragment kinetic-energy spectra. The results indicate emission from nuclei near normal nuclear density below an excitation energy E*/A≲2 MeV, followed by a gradual decrease to a near-constant value of ρ/ρ0˜0.3 for E*/A≳5 MeV. Temperatures derived from these data with a density-dependent Fermi-gas model yield a nuclear caloric curve that is generally consistent with those derived from isotope ratios.

  17. Thermal evolution of cometary nuclei

    NASA Technical Reports Server (NTRS)

    Prialnik, Dina

    1989-01-01

    The long-term thermal evolution in models of comet nuclei is examined. Models of the nucleus surface and interior are discussed and the equations of comet nucleus evolution are analyzed. The thermal evolution of a nucleus in Comet P/Halley's orbit is outlined. The effects of temperature, composition, and orbital parameters on the evolutionary course are examined. Consideration is given to the implications of the assumption that new comets are pristine objects which have undergone little alteration and constitute a source of original solar nebula material.

  18. Signatures of α clustering in light nuclei from relativistic nuclear collisions.

    PubMed

    Broniowski, Wojciech; Ruiz Arriola, Enrique

    2014-03-21

    We argue that relativistic nuclear collisions may provide experimental evidence of α clustering in light nuclei. A light α-clustered nucleus has a large intrinsic deformation. When collided against a heavy nucleus at very high energies, this deformation transforms into the deformation of the fireball in the transverse plane. The subsequent collective evolution of the fireball leads to harmonic flow reflecting the deformation of the initial shape, which can be measured with standard methods of relativistic heavy-ion collisions. We illustrate the feasibility of the idea by modeling the (12)C-(208)Pb collisions and point out that very significant quantitative and qualitative differences between the α-clustered and uniform (12)C nucleus occur in such quantities as the triangular flow, its event-by-event fluctuations, or the correlations of the elliptic and triangular flows. The proposal offers a possibility of studying low-energy nuclear structure phenomena with "snapshots" made with relativistic heavy-ion collisions.

  19. ON THE SPIN CORRELATIONS OF MUONS AND TAU LEPTONS GENERATED IN THE ANNIHILATION PROCESSES e+e- → μ+μ-, e+e- → τ+τ-

    NASA Astrophysics Data System (ADS)

    Lyuboshitz, Valery V.; Lyuboshitz, Vladimir L.

    2014-12-01

    Using the technique of helicity amplitudes, the electromagnetic process e+e- → μ+μ-(τ+τ-) is theoretically studied in the one-photon approximation. The structure of the triplet states of the final (μ+μ-) system is analyzed. It is shown that in the case of unpolarized electron and positron the final muons are also unpolarized, but their spins are strongly correlated. Explicit expressions for the components of the correlation tensor of the (μ+μ-) system are derived. The formula for the angular correlation at the decays of final muons μ+ and μ- is obtained. It is demonstrated that spin correlations of muons in the considered process have the purely quantum character, since one of the Bell-type incoherence inequalities for the correlation tensor components is always violated.

  20. Quantal rotation and its coupling to intrinsic motion in nuclei

    NASA Astrophysics Data System (ADS)

    Nakatsukasa, Takashi; Matsuyanagi, Kenichi; Matsuzaki, Masayuki; Shimizu, Yoshifumi R.

    2016-07-01

    Symmetry breaking is an important concept in nuclear physics and other fields of physics. Self-consistent coupling between the mean-field potential and the single-particle motion is a key ingredient in the unified model of Bohr and Mottelson, which could lead to a deformed nucleus as a consequence of spontaneous breaking of the rotational symmetry. Some remarks on the finite-size quantum effects are given. In finite nuclei, the deformation inevitably introduces the rotation as a symmetry-restoring collective motion (Anderson-Nambu-Goldstone mode), and the rotation affects the intrinsic motion. In order to investigate the interplay between the rotational and intrinsic motions in a variety of collective phenomena, we use the cranking prescription together with the quasiparticle random phase approximation (QRPA). At low spin, the coupling effect can be seen in the generalized intensity relation. A feasible quantization of the cranking model is presented, which provides a microscopic approach to the higher-order intensity relation. At high spin, the semiclassical cranking prescription works well. We discuss properties of collective vibrational motions under rapid rotation and/or large deformation. The superdeformed shell structure plays a key role in emergence of a new soft mode which could lead to instability toward the {K}π ={1}- octupole shape. A wobbling mode of excitation, which is a clear signature of the triaxiality, is discussed in terms of a microscopic point of view. A crucial role played by the quasiparticle alignment is presented.

  1. Measuring the Higgs-vector boson couplings at linear e+e- collider

    NASA Astrophysics Data System (ADS)

    Dutta, Sukanta; Hagiwara, Kaoru; Matsumoto, Yu

    2008-12-01

    We estimate the accuracy with which the coefficient of the CP even dimension-six operators involving Higgs and two vector bosons (HVV) can be measured at linear e+e- colliders. Using the optimal observables method for the kinematic distributions, our analysis is based on the five different processes. First is the WW fusion process in the t-channel (e+e-→ν¯eνeH), where we use the rapidity y and the transverse momentum pT of the Higgs boson as observables. Second is the ZH pair production process in the s channel, where we use the scattering angle of the Z and the Z decay angular distributions, reproducing the results of the previous studies. Third is the t-channel ZZ, fusion processes (e+e-→e+e-H), where we use the energy and angular distributions of the tagged e+ and e-. In the fourth, we consider the rapidity distribution of the untagged e+e-H events, which can be approximated well as the γγ fusion of the bremsstrahlung photons from e+ and e- beams. As the last process, we consider the single-tagged e+e-H events, which probe the γe±→He± process. All the results are presented in such a way that statistical errors of the constraints on the effective couplings and their correlations are read off when all of them are allowed to vary simultaneously, for each of the above processes, for mH=120GeV, at s=250GeV, 350 GeV, 500 GeV, and 1 TeV, with and without e- beam polarization of 80%. We find, for instance, that the HZZ and HWW couplings can be measured with 0.6% and 0.9% accuracy, respectively, for the integrated luminosity of L=100fb-1 at s=250GeV, 350 GeV, and L=500fb-1 at s=500GeV, 1 TeV, for the luminosity uncertainty of 1% at each energy. We find that the luminosity uncertainty affects only one combination of the nonstandard couplings, which are proportional to the standard HWW and HZZ couplings, while it does not affect the errors of the other independent combinations of the couplings. As a consequence, we observe that a few combinations of the eight

  2. Transcription in Isolated Wheat Nuclei

    PubMed Central

    Luthe, Dawn Sywassink; Quatrano, Ralph S.

    1980-01-01

    Nuclei free of RNase activity were isolated from 3-hour-imbibed wheat (var. Yamhill) embryos by centrifugation through a discontinuous gradient of Percoll. The maximum rate of RNA synthesis observed in these nuclei was approximately 5 picomoles [3H]UTP per milligram DNA per minute. Two monovalent cation optima were found when measured in the presence of 15 millimolar MgCl2 or 2 millimolar MnCl2; 15 and 75 millimolar (NH4)2SO4. At the high monovalent cation optimum, the rate of RNA synthesis was linear for the first 10 to 15 minutes of incubation and still increasing after 3 hours. RNA synthesized in vitro (30-minute pulse followed by a 30-minute chase) showed distinct 18 and 26S RNA peaks comprising 13 and 17% of the total radioactivity, respectively. The over-all pattern of RNA synthesized in vitro was similar to the in vivo pattern. Approximately 40 to 50% of the RNA synthesized was inhibited by α-amanitin at 4 micrograms per milliliter. The newly synthesized 6 to 10S RNA appeared to be selectively inhibited by α-amanitin. PMID:16661179

  3. Physical Processing of Cometary Nuclei

    NASA Technical Reports Server (NTRS)

    Weissman, Paul R.; Stern, S. Alan

    1997-01-01

    Cometary nuclei preserve a cosmo-chemical record of conditions and processes in the primordial solar nebula, and possibly even the interstellar medium. However, that record is not perfectly preserved over the age of the solar system due to a variety of physical processes which act to modify cometary surfaces and interiors. Possible structural and/or internal processes include: collisional accretion, disruption, and reassembly during formation; internal heating by long and short-lived radionuclides; amorphous to crystalline phase transitions, and thermal stresses. Identified surface modification processes include: irradiation by galactic cosmic rays, solar protons, UV photons, and the Sun's T Tauri stage mass outflow; heating by passing stars and nearby supernovae; gardening by debris impacts; the accretion of interstellar dust and gas and accompanying erosion by hypervelocity dust impacts and sputtering; and solar heating with accompanying crust formation. These modification processes must be taken into account in both the planning and the interpretation of the results of a Comet Nucleus Sample Return Mission. Sampling of nuclei should be done at as great a depth below the surface crust as technically feasible, and at vents or fissures leading to exposed volatiles at depth. Samples of the expected cometary crust and near-surface layers also need to be returned for analysis to achieve a better understanding of the effects of these physical processes. We stress that comets are still likely less modified dm any other solar system bodies, but the degree of modification can vary greatly from one comet to the next.

  4. Physical Processing of Cometary Nuclei

    NASA Astrophysics Data System (ADS)

    Weissman, Paul R.; Stern, S. Alan

    1997-12-01

    Cometary nuclei preserve a cosmo-chemical record of conditions and processes in the primordial solar nebula, and possibly even the interstellar medium. However, that record is not perfectly preserved over the age of the solar system due to a variety of physical processes which act to modify cometary surfaces and interiors. Possible structural and/or internal processes include: collisional accretion, disruption, and reassembly during formation; internal heating by long and short-lived radionuclides; amorphous to crystalline phase transitions, and thermal stresses. Identified surface modification processes include: irradiation by galactic cosmic rays, solar protons, UV photons, and the Sun's T Tauri stage mass outflow; heating by passing stars and nearby supernovae; gardening by debris impacts; the accretion of interstellar dust and gas and accompanying erosion by hypervelocity dust impacts and sputtering; and solar heating with accompanying crust formation. These modification processes must be taken into account in both the planning and the interpretation of the results of a Comet Nucleus Sample Return Mission. Sampling of nuclei should be done at as great a depth below the surface crust as technically feasible, and at vents or fissures leading to exposed volatiles at depth. Samples of the expected cometary crust and near-surface layers also need to be returned for analysis to achieve a better understanding of the effects of these physical processes. We stress that comets are still likely less modified dm any other solar system bodies, but the degree of modification can vary greatly from one comet to the next.

  5. ISOLATION OF SKELETAL MUSCLE NUCLEI

    PubMed Central

    Edelman, Jean C.; Edelman, P. Michael; Knigge, Karl M.; Schwartz, Irving L.

    1965-01-01

    A method employing aqueous media for isolation of nuclei from rat skeletal muscle is described. The technique involves (a) mincing and then homogenizing in a 0.32 M sucrose-salt solution with a Potter-Elvehjem type homogenizer using a Delrin (an acetal resin) pestle and a carefully controlled, relatively large pestle-to-glass clearance, (b) filtering through fiberglass and stainless steel screens of predetermined mesh size to remove myofibrils and connective tissue, and (c) centrifuging in a 2.15 M sucrose-salt solution containing 0.7 mM ATP. Electron and phase-contrast microscopic observations show that the nuclei are intact, unencumbered by cytoplasmic tags, and possess well preserved distinct nucleoli, nucleoplasm, and nuclear membranes. Cytoplasmic contamination is minimal and mainly mitochondrial. Chemical assays of the nuclear fraction show that the DNA/protein and RNA/DNA ratios are comparable to those obtained in other tissues. These ratios, as well as the low specific activity obtained for cytochrome c oxidase and the virtual absence of myofibrillar ATPase, indicate a high degree of purity with minimal mitochondrial and myofibrillar contamination. The steps comprising the technique and the reasons for their selection are discussed. PMID:4287141

  6. Mass-23 nuclei in astrophysics

    NASA Astrophysics Data System (ADS)

    Fraser, P. R.; Amos, K.; Canton, L.; Karataglidis, S.; Svenne, J. P.; van der Kniff, D.

    2015-09-01

    The formation of mass-23 nuclei by radiative capture is of great interest in astrophysics. A topical problem associated with these isobars is the so-called 22Na puzzle of ONe white dwarf novae, where the abundance of 22Na observed is not as is predicted by current stellar models, indicating there is more to learn about how the distribution of elements in the universe occurred. Another concerns unexplained variations in elements abundance on the surface of aging red giant stars. One method for theoretically studying nuclear scattering is the Multi-Channel Algebraic Scattering (MCAS) formalism. Studies to date have used a simple collective-rotor prescription to model the target states which couple to projectile nucleons. While, in general, the target states considered all belong to the ground state rotor band, for some systems it is necessary to include coupling to states outside of this band. Herein we discuss an extension of MCAS to allow coupling of different strengths between such states and the ground state band. This consideration is essential when studying the scattering of neutrons from 22Ne, a necessary step in studying the mass-23 nuclei mentioned above.

  7. High spin spectroscopy for odd-Z nuclei with A approx 160

    SciTech Connect

    Yu, C.-H. Tennessee Univ., Knoxville, TN . Dept. of Physics and Astronomy); Gascon, J.; Hagemann, G.B. ); Garrett, J.D. Oak Ridge National Lab., TN )

    1989-01-01

    Experimental routhians, alignments, band crossing frequencies, and the B(M1)/B(E2) ratios of the N = 90 isotones and several light Lu (N = 90--96) isotopes are summarized and discussed in terms of shape changes. This systematic analysis shows a neutron- and proton-number dependent quadrupole and {gamma} deformations for these light rare earth nuclei. The stability of the nuclear deformation with respect to {beta} and {gamma} is also found to be particle-number dependent. Such particle-number dependent shapes can be attributed to the different locations of the proton and neutron Fermi levels in the Nilsson diagrams. Configurations dependent shapes are discussed specially concerning the deformation difference between the proton h{sub 9/2} {1/2}{sup {minus}}(541) and the high-K h{sub 11/2} configurations. The observed large neutron band crossing frequencies in the h{sub 9/2} {1/2}{sup {minus}}(541) configuration support the predicted large deformation of this configuration, but can be reproduced by the self-consistent cranked shell model calculation. Lifetime measurement for {sup 157}Ho, one of the nuclei that show such a large {h bar}{omega}{sub c} in the {1/2}{sup {minus}}(541) band, indicates that deformation difference can only account for 20% of such shift in {h bar}{omega}{sub c}. 55 refs., 12 figs.

  8. Description of the Ba-Dy(N = 92) nuclei in the interacting boson model

    NASA Astrophysics Data System (ADS)

    Kassim, Huda H.

    Interacting Boson Model (IBM -1) has been used to study the energy levels and B(E2) transition rates in Ba-Dy (N = 92) isotones. A simplified Hamiltonian is used which is written in the creation and annihilation form and for each nucleus, by fitting the selected experimental energy levels and B(E2) transition rates with the calculated ones to get the best model parameters. Using the (IBM) Hamiltonian with an intrinsic state formalism, the potential energy surfaces (PES) for even-even Ba-Dy nuclei have been obtained and the contour plot of PES show that the shape phase transitions from spherical U(5) to deformed shape SU(3) has been determined for the 148Ba, while 150Ce, 152Nd, 154Sm, 156Gd and 158Dy nuclei are deformed and have rotational-like characters. The behavior of energy and B(E2) ratios in the ground state band are examined.

  9. Studies of the shapes of heavy pear-shaped nuclei at ISOLDE

    NASA Astrophysics Data System (ADS)

    Butler, P. A.

    2016-07-01

    For certain combinations of protons and neutrons there is a theoretical expectation that the shape of nuclei can assume octupole deformation, which would give rise to reflection asymmetry or a "pear-shape" in the intrinsic frame, either dynamically (octupole vibrations) or statically (permanent octupole deformation). I will briefly review the historic evidence for reflection asymmetry in nuclei and describe how recent experiments carried out at REX-ISOLDE have constrained nuclear theory and how they contribute to tests of extensions of the Standard Model. I will also discuss future prospects for measuring nuclear shapes from Coulomb Excitation: experiments are being planned that will exploit beams from HIE-ISOLDE that are cooled in the TSR storage ring and injected into a solenoidal spectrometer similar to the HELIOS device developed at the Argonne National Laboratory.

  10. Nilsson-SU3 self-consistency in heavy N =Z nuclei

    NASA Astrophysics Data System (ADS)

    Zuker, A. P.; Poves, A.; Nowacki, F.; Lenzi, S. M.

    2015-08-01

    It is argued that there exist natural shell-model spaces optimally adapted to the operation of two variants of Elliott's SU3 symmetry that provide accurate predictions of quadrupole moments of deformed states. A self-consistent Nilsson-like calculation describes the competition between the realistic quadrupole force and the central field, indicating a remarkable stability of the quadrupole moments—which remain close to their quasi- and pseudo-SU3 values—as the single-particle splittings increase. A detailed study of the N =Z even nuclei from 56Ni to 96Cd reveals that the region of prolate deformation is bounded by a pair of transitional nuclei 72Kr and 84Mo in which prolate ground-state bands are predicted to dominate, though coexisting with oblate ones.

  11. Studies of the shapes of heavy pear-shaped nuclei at ISOLDE

    SciTech Connect

    Butler, P. A.

    2016-07-07

    For certain combinations of protons and neutrons there is a theoretical expectation that the shape of nuclei can assume octupole deformation, which would give rise to reflection asymmetry or a ”pear-shape” in the intrinsic frame, either dynamically (octupole vibrations) or statically (permanent octupole deformation). I will briefly review the historic evidence for reflection asymmetry in nuclei and describe how recent experiments carried out at REX-ISOLDE have constrained nuclear theory and how they contribute to tests of extensions of the Standard Model. I will also discuss future prospects for measuring nuclear shapes from Coulomb Excitation: experiments are being planned that will exploit beams from HIE-ISOLDE that are cooled in the TSR storage ring and injected into a solenoidal spectrometer similar to the HELIOS device developed at the Argonne National Laboratory.

  12. Systematics of α-decay and spontaneous fission half-lives of super-heavy nuclei

    NASA Astrophysics Data System (ADS)

    Silisteanu, Ion; Anghel, Claudia-Ioana

    2017-01-01

    Simple relationships derived from the systematics of data and calculated α-decay and spontaneous fission half-lives are used to predict half-lives and branches for many still unknown super-heavy nuclei. Half-life calculations are performed within the shell model rate theory for α-decay, and a dynamical approach for spontaneous fission defined essentially by the shape, the hight of fission barrier, the fissility and nuclear deformations. Extensive half-lives predictions are made for many unknown super-heavy nuclei. The comparison of the behavior of measured α-decay properties with expectations from theoretical approximations (with and without; finite size corrections, resonance scattering effects, deformations and shell structure) provides insight into the accuracy of current nuclear models for the reaction dynamics and structure.

  13. Fusion-fission probabilities, cross sections, and structure notes of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Kowal, Michał; Cap, Tomasz; Jachimowicz, Piotr; Skalski, Janusz; Siwek-Wilczyńska, Krystyna; Wilczyński, Janusz

    2016-12-01

    Fusion - fission probabilities in the synthesis of heaviest elements are discussed in the context of the latest experimental reports. Cross sections for superheavy nuclei are evaluated using the "Fusion by Diffusion" (FBD) model. Predictive power of this approach is shown for experimentally known Lv and Og isotopes and predictions given for Z = 119, 120. Ground state and saddle point properties as masses, shell corrections, pairing energies, and deformations necessary for cross-section estimations are calculated systematically within the multidimensional microscopic-macroscopic method based on the deformed Woods-Saxon single-particle potential. In the frame of the FBD approach predictions for production of elements heavier than Z = 118 are not too optimistic. For this reason, and because of high instability of superheavy nuclei, we comment on some structure effects, connected with the K-isomerism phenomenon which could lead to a significant increase in the stability of these systems.

  14. Gamma-ray spectroscopy of proton drip-line nuclei

    NASA Astrophysics Data System (ADS)

    Seweryniak, Dariusz

    1998-10-01

    Spectroscopy of nuclei far from the line of stability extends our knowledge of nuclear systems characterized by extreme values of nuclear isospin. The collapse and appearance of magic numbers, the onset of new regions of deformation, new decay modes are predicted for nuclei with exotic isospin composition. Despite continuous progress, the neutron drip-line has not been reached experimentally, but for the light elements. However, modern experimental techniques have made studies of nuclei at the limits of proton stability possible. For example, thanks to recent proton-decay studies, the proton drip-line was almost completely delineated for elements between Z=51 and Z=83(P.J. Woods and C. Davids, Ann. Rev. Nucl. and Part. Sci. 47), 541 (1997). Large arrays of Ge detectors combined with ancillary detectors facilitating reaction channel selection have provided a vast amount of in-beam spectroscopic data across the nuclidic chart. The Recoil-Decay Tagging (RDT) method(R.S. Simon et al., Z. Phys. A325) 197 (1986) and E.S. Paul, P.J. Woods et al., Phys. Rev. C51, 78 (1995), which takes advantage of the high selectivity of alpha- and proton-decay studies, has been particularly successful. GAMMASPHERE coupled with the Fragment Mass Analyzer at the Argonne National Laboratory represents the state-of-the-art system for RDT experiments. Since its commissioning in the beginning of 1998, excited states in many nuclei situated at or even beyond the proton drip-line (ranging from the ^100Sn region through actinide nuclides) were observed. Among others, transitions feeding the ground-state and the isomeric state in the deformed proton emitter ^141Ho(C.N. Davids et al., Phys. Rev. Lett. 80), 1849 (1998) were selected(P.J. Woods et al., private communication). The cross section for populating the isomer is about 50 nb and it represents the weakest channel ever observed in an in-beam experiment. During this talk the Recoil Decay Tagging Method will be introduced and the results

  15. Lifetime Measurements and Deformation in ^79Sr

    NASA Astrophysics Data System (ADS)

    Ryu, Y. K.; Kaye, R. A.; Arora, S. R.; Tabor, S. L.; Baldwin, T.; Campbell, D. B.; Chandler, C.; Cooper, M. W.; Hoffman, C. R.; Pavan, J.; Wiedeking, M.; D"Oring, J.; Sun, Y.; Gerbick, S. M.; Grubor-Urosevic, O.; Riley, L. A.

    2006-10-01

    High-spin states in ^79Sr were produced following the ^54Fe(^28Si, 2pn) fusion-evaporation reaction using a beam energy of 90 MeV at the Florida State University (FSU) Tandem-Linac facility, and the resulting de-exciting γ rays were detected with the FSU Ge array of 10 Compton-suppressed detectors. The ^54Fe target was thick enough so that all of the synthesized nuclei could stop completely in the target, resulting in Doppler-shifted γ-ray line shapes that could be analyzed using the Doppler-shift attenuation method. In all, 23 lifetimes were measured in three separate band structures using this method, and then used to infer transition quadrupole moments (Qt) and quadrupole deformations (β2) using the rotational model. The results show good qualitative agreement with the predictions of both cranked Woods-Saxon (CWS) and projected shell model (PSM) calculations. The band based on a d5/2 single-particle orbit, verified in this study through γ- γ coincidences, intensity measurements, and directional correlation of oriented nuclei (DCO) ratios, was found to have the largest average deformation (β2,ave= 0.41) among the three bands, in agreement with the CWS and PSM predictions. Supported in part by the NSF and the OWU SSRP.

  16. Lifetime Measurements and Deformation in ^79Sr

    NASA Astrophysics Data System (ADS)

    Ryu, Y. K.; Kaye, R. A.; Arora, S. R.; Tabor, S. L.; Baldwin, T.; Campbell, D. B.; Chandler, C.; Cooper, M. W.; Hoffman, C. R.; Pavan, J.; Wiedeking, M.; D"Oring, J.; Sun, Y.; Gerbick, S. M.; Grubor-Urosevic, O.; Riley, L. A.

    2006-10-01

    High-spin states in ^79Sr were produced following the ^54Fe(^28Si, 2pn) fusion-evaporation reaction using a beam energy of 90 MeV at the Florida State University (FSU) Tandem-Linac facility, and the resulting de-exciting γ rays were detected with the FSU Ge array of 10 Compton-suppressed detectors. The ^54Fe target was thick enough so that all of the synthesized nuclei could stop completely in the target, resulting in Doppler-shifted γ-ray line shapes that could be analyzed using the Doppler-shift attenuation method. In all, 23 lifetimes were measured in three separate band structures using this method, and then used to infer transition quadrupole moments (Qt) and quadrupole deformations (β2) using the rotational model. The results show good qualitative agreement with the predictions of both cranked Woods-Saxon (CWS) and projected shell model (PSM) calculations. The band based on a d5/2 single-particle orbit, verified in this study through γ- γ coincidences, intensity measurements, and directional correlation of oriented nuclei (DCO) ratios, was found to have the largest average deformation (β2,ave = 0.41) among the three bands, in agreement with the CWS and PSM predictions.

  17. Bridging the nuclear structure gap between stable and super heavy nuclei.

    SciTech Connect

    Seweryniak, D.; Khoo, T. L.; Ahmad, I.; Kondev, F. G.; Robinson, A.; Back, B. B.; Carpenter, M. P.; Davids, C. N.; Greene, J. P.; Gros, S.; Janssens, R. V. F.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Peterson, D.; Zhu, S. F.; Physics; Univ. of York; Univ. of Massachusetts at Lowell; Japan Atomic Energy Agency; Univ. of Jyvaskyla; CSNSM Orsay; Yale Univ.; Univ. of Liverpool; RIKEN; Univ. of Maryland; Univ. of Notre Dame

    2010-01-01

    Due to recent advances in detection techniques, excited states in several trans-fermium nuclei were studied in many laboratories worldwide, shedding light on the evolution of nuclear structure between stable nuclei and the predicted island of stability centered around spherical magic numbers. In particular, studies of K-isomers around the Z=100 and N=152 deformed shell closures extended information on the energies of Nilsson orbitals at the Fermi surface. Some of these orbitals originate from spherical states, which are relevant to the magic gaps in super-heavy nuclei. The single-particle energies can be used to test various theoretical predictions and aid in extrapolations towards heavier systems. So far, the Woods-Saxon potential reproduces the data best, while self-consistent approaches miss some of the observed features, indicating a need to modify the underlying effective nucleon-nucleon interactions.

  18. Bridging the nuclear structure gap between stable and super heavy nuclei

    NASA Astrophysics Data System (ADS)

    Seweryniak, D.; Khoo, T. L.; Ahmad, I.; Kondev, F. G.; Robinson, A.; Tandel, S. K.; Asai, M.; Back, B. B.; Carpenter, M. P.; Chowdhury, P.; Davids, C. N.; Eeckhaudt, S.; Greene, J. P.; Greenlees, P. T.; Gros, S.; Hauschild, K.; Heinz, A.; Herzberg, R.-D.; Janssens, R. V. F.; Jenkins, D. G.; Jones, G. D.; Ketelhut, S.; Lauritsen, T.; Lister, C. J.; Lopez-Martens, A.; Marley, P.; McCutchan, E. A.; Nakatsukasa, T.; Papadakis, P.; Peterson, D.; Qian, J.; Rostron, D.; Stefanescu, I.; Tandel, U. S.; Wang, X. F.; Zhu, S. F.

    2010-03-01

    Due to recent advances in detection techniques, excited states in several trans-fermium nuclei were studied in many laboratories worldwide, shedding light on the evolution of nuclear structure between stable nuclei and the predicted island of stability centered around spherical magic numbers. In particular, studies of K-isomers around the Z=100 and N=152 deformed shell closures extended information on the energies of Nilsson orbitals at the Fermi surface. Some of these orbitals originate from spherical states, which are relevant to the magic gaps in super-heavy nuclei. The single-particle energies can be used to test various theoretical predictions and aid in extrapolations towards heavier systems. So far, the Woods-Saxon potential reproduces the data best, while self-consistent approaches miss some of the observed features, indicating a need to modify the underlying effective nucleon-nucleon interactions.

  19. PHYSICAL STUDIES OF ISOLATED EUCARYOTIC NUCLEI

    PubMed Central

    Olins, Donald E.; Olins, Ada L.

    1972-01-01

    The degree of chromatin condensation in isolated rat liver nuclei and chicken erythrocyte nuclei was studied by phase-contrast microscopy as a function of solvent pH, K+ and Mg++ concentrations Data were represented as "phase" maps, and standard solvent conditions selected that reproducibly yield granular, slightly granular, and homogeneous nuclei Nuclei in these various states were examined by ultraviolet absorption and circular dichroism (CD) spectroscopy, low-angle X-ray diffraction, electron microscopy, and binding capacity for ethidium bromide Homogeneous nuclei exhibited absorption and CD spectra resembling those of isolated nucleohistone. Suspensions of granular nuclei showed marked turbidity and absorption flattening, and a characteristic blue-shift of a crossover wavelength in the CD spectra. In all solvent conditions studied, except pH < 2 3, low-angle X-ray reflections characteristic of the native, presumably superhelical, nucleohistone were observed from pellets of intact nuclei. Threads (100–200 A diameter) were present in the condensed and dispersed phases of nuclei fixed under the standard solvent conditions, and examined in the electron microscope after thin sectioning and staining Nuclei at neutral pH, with different degrees of chromatin condensation, exhibited similar binding capacities for ethidium bromide. These data suggest a model that views chromatin condensation as a close packing of superhelical nucleohistone threads but still permits condensed chromatin to respond rapidly to alterations in solvent environment. PMID:4554987

  20. Production of the spin partner of the X (3872) in e+e- collisions

    NASA Astrophysics Data System (ADS)

    Guo, Feng-Kun; Meißner, Ulf-G.; Yang, Zhi

    2015-01-01

    We study the production of the spin partner of the X (3872), which is a D*Dbar* bound state with quantum numbers JPC =2++ and named X2 (4012) here, with the associated emission of a photon in electron-positron collisions. The results show that the ideal energy region to observe the X2 (4012) in e+e- annihilations is from 4.4 GeV to 4.5 GeV, due to the presence of the S-wave Dbar*D1 (2420) and Dbar*D2 (2460) thresholds, respectively. We also point out that it will be difficult to observe the γX (4012) at the e+e- center-of-mass energy around 4.26 GeV.

  1. Mixed electroweak-QCD corrections to e+e-→H Z at Higgs factories

    NASA Astrophysics Data System (ADS)

    Sun, Qing-Feng; Feng, Feng; Jia, Yu; Sang, Wen-Long

    2017-09-01

    The prospective Higgs factories, exemplified by ILC, FCC-ee and CEPC, plan to conduct precision Higgs measurements at the e+e- center-of-mass energy around 250 GeV. The cross sections for the dominant Higgs production channel, the Higgsstrahlung process, can be measured to a (sub)percent accuracy. Merely incorporating the well-known next-to-leading-order (NLO) electroweak corrections appears to be far from sufficient to match the unprecedented experimental precision. In this work, we make an important advancement toward this direction by investigating the mixed electroweak-QCD corrections to e+e-→H Z at next-to-next-to-leading order (NNLO) for both unpolarized and polarized Z bosons. The corrections turn out to reach the 1% level of the Born order results, and thereby must be incorporated in future confrontations with the data.

  2. DATA REVIEW: A compilation of data on hadronic total cross sections in e+e- interactions

    NASA Astrophysics Data System (ADS)

    Whalley, M. R.

    2003-12-01

    A comprehensive compilation of experimental data on total hadronic cross sections, and R ratios, in e+e- interactions is presented. Published data from the Novosibirsk, Orsay, Frascati, SLAC, CORNELL, DESY, KEK and CERN e+e- colliders on both exclusive and inclusive final particle states are included from threshold energies to the highest LEP energies. The data are presented in tabular form supplemented by compilation plots of different exclusive final particle states and of different energy regions. All the data in this review, together with data on a wide variety of other reactions, can be found in, and retrieved from, the Durham HEP Databases on the World Wide Web http://durpdg.dur.ac.uk/HEPDATA.

  3. Observation of eta' decays to pi+pi-pi0 and pi+pi-e+e-.

    PubMed

    Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Reed, J; Robichaud, A N; Tatishvili, G; Briere, R A; Vogel, H; Onyisi, P U E; Rosner, J L; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hunt, J M; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Ledoux, J; Mahlke-Krüger, H; Mohapatra, D; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Yelton, J; Rubin, P; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tan, B J Y; Tomaradze, A; Libby, J; Martin, L; Powell, A; Wilkinson, G; Mendez, H; Ge, J Y; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Ecklund, K M

    2009-02-13

    Using psi(2S)-->pi;{+}pi;{-}J/psi, J/psi-->gammaeta;{'} events acquired with the CLEO-c detector at the CESR e;{+}e;{-} collider, we make the first observations of the decays eta;{'}-->pi;{+}pi;{-}pi;{0} and eta;{'}-->pi;{+}pi;{-}e;{+}e;{-}, measuring absolute branching fractions (37_{-9};{+11}+/-4)x10;{-4} and (25_{-9};{+12}+/-5)x10;{-4}, respectively. For eta;{'}-->pi;{+}pi;{-}pi;{0}, this result probes the mechanism of isospin violation and the roles of pi;{0}/eta/eta;{'}-mixing and final state rescattering in strong decays. We also set upper limits on branching fractions for eta;{'} decays to pi;{+}pi;{-}micro;{+}micro;{-}, 2(pi;{+}pi;{-}), pi;{+}pi;{-}2pi;{0}, 2(pi;{+}pi;{-})pi;{0}, 3(pi;{+}pi;{-}), and invisible final states.

  4. Phenomenology of a Higgs triplet model at future e+e- colliders

    NASA Astrophysics Data System (ADS)

    Blunier, Sylvain; Cottin, Giovanna; Díaz, Marco A.; Koch, Benjamin

    2017-04-01

    In this work, we investigate the prospects of future e+e- colliders in testing a Higgs triplet model with a scalar triplet and a scalar singlet under S U (2 ). The parameters of the model are fixed so that the lightest C P -even state corresponds to the Higgs particle observed at the LHC at around 125 GeV. This study investigates if the second heaviest C P -even, the heaviest C P -odd and the singly charged states can be observed at existing and future colliders by computing their accessible production and decay channels. In general, the LHC is not well equipped to produce a Higgs boson which is not mainly doubletlike, so we turn our focus to lepton colliders. We find distinctive features of this model in cases where the second heaviest C P -even Higgs is tripletlike, singletlike or a mixture. These features could distinguish the model from other scenarios at future e+e- colliders.

  5. Estimates of Hadronic Backgrounds in Future e+e- LinearColliders

    SciTech Connect

    Ohgaki, Tomomi

    1998-05-01

    We have estimated hadronic backgrounds for an e+e- linear collider at a center- of-mass energy of 5 TeV. In order to achieve a required luminosity in TeV e+ e- colliders, the high beamstrahlung parameter {Upsilon}, such as several thousands, is caused. In the high {Upsilon} regime, the {gamma}{gamma} luminosities due to the collision of beamstrahlung photons are calculated by using the CAIN code. According to the {gamma}{gamma} luminosity distribution, we have estimated the hadronic backgrounds of {gamma}{gamma} {yields} minijets based on the parton distributions of the Drees and Grassie model by the PYTHIA 5.7 code. The Japan Linear Collider (J LC-1) detector simulator is applied for selection performances in the detector.

  6. Search for the rare decay K(L)-->pi(0)e(+)e(-).

    PubMed

    Alavi-Harati, A; Alexopoulos, T; Arenton, M; Barbosa, R F; Barker, A R; Barrio, M; Bellantoni, L; Bellavance, A; Blucher, E; Bock, G J; Bown, C; Bright, S; Cheu, E; Coleman, R; Corcoran, M D; Cox, B; Erwin, A R; Escobar, C O; Ford, R; Glazov, A; Golossanov, A; Gomes, R A; Gouffon, P; Graham, J; Hamm, J; Hanagaki, K; Hsiung, Y B; Huang, H; Jejer, V; Jensen, D A; Kessler, R; Kobrak, H G E; Kotera, K; LaDue, J; Lai, N; Ledovskoy, A; McBride, P L; Monnier, E; Nelson, K S; Nguyen, H; Ping, H; Prasad, V; Qi, X R; Quinn, B; Ramberg, E J; Ray, R E; Ronquest, M; Santos, E; Senyo, K; Shanahan, P; Shields, J; Slater, W; Smith, D E; Solomey, N; Swallow, E C; Taegar, S A; Tesarek, R J; Toale, P A; Tschirhart, R; Velissaris, C; Wah, Y W; Wang, J; White, H B; Whitmore, J; Wilking, M; Winstein, B; Winston, R; Worcester, E T; Yamanaka, T; Zukanovich, R F

    2004-07-09

    The KTeV/E799 experiment at Fermilab has searched for the rare kaon decay K(L)-->pi(0)e(+)e(-). This mode is expected to have a significant CP violating component. The measurement of its branching ratio could support the standard model or could indicate the existence of new physics. This Letter reports new results from the 1999-2000 data set. One event is observed with an expected background at 0.99+/-0.35 events. We set a limit on the branching ratio of 3.5x10(-10) at the 90% confidence level. Combining with the previous result based on the data set taken in 1997 yields the final KTeV result: BR(K(L)-->pi(0)e(+)e(-))<2.8x10(-10) at 90% C.L.

  7. Slow down of a globally neutral relativistic e-e+ beam shearing the vacuum

    NASA Astrophysics Data System (ADS)

    Alves, E. P.; Grismayer, T.; Silveirinha, M. G.; Fonseca, R. A.; Silva, L. O.

    2016-01-01

    The microphysics of relativistic collisionless shear flows is investigated in a configuration consisting of a globally neutral, relativistic {{e}-}{{e}+} beam streaming through a hollow plasma/dielectric channel. We show through multidimensional particle-in-cell simulations that this scenario excites the mushroom instability (MI), a transverse shear instability on the electron-scale, when there is no overlap (no contact) between the {{e}-}{{e}+} beam and the walls of the hollow plasma channel. The onset of the MI leads to the conversion of the beam’s kinetic energy into magnetic (and electric) field energy, effectively slowing down a globally neutral body in the absence of contact. The collisionless shear physics explored in this configuration may operate in astrophysical environments, particularly in highly relativistic and supersonic settings where macroscopic shear processes are stable.

  8. Search for a dark photon in e(+)e(-) collisions at BABAR.

    PubMed

    Lees, J P; Poireau, V; Tisserand, V; Grauges, E; Palano, A; Eigen, G; Stugu, B; Brown, D N; Feng, M; Kerth, L T; Kolomensky, Yu G; Lee, M J; Lynch, G; Koch, H; Schroeder, T; Hearty, C; Mattison, T S; McKenna, J A; So, R Y; Khan, A; Blinov, V E; Buzykaev, A R; Druzhinin, V P; Golubev, V B; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Lankford, A J; Mandelkern, M; Dey, B; Gary, J W; Long, O; Campagnari, C; Franco Sevilla, M; Hong, T M; Kovalskyi, D; Richman, J D; West, C A; Eisner, A M; Lockman, W S; Panduro Vazquez, W; Schumm, B A; Seiden, A; Chao, D S; Cheng, C H; Echenard, B; Flood, K T; Hitlin, D G; Miyashita, T S; Ongmongkolkul, P; Porter, F C; Andreassen, R; Huard, Z; Meadows, B T; Pushpawela, B G; Sokoloff, M D; Sun, L; Bloom, P C; Ford, W T; Gaz, A; Smith, J G; Wagner, S R; Ayad, R; Toki, W H; Spaan, B; Bernard, D; Verderi, M; Playfer, S; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Fioravanti, E; Garzia, I; Luppi, E; Piemontese, L; Santoro, V; Calcaterra, A; de Sangro, R; Finocchiaro, G; Martellotti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Contri, R; Lo Vetere, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Bhuyan, B; Prasad, V; Adametz, A; Uwer, U; Lacker, H M; Dauncey, P D; Mallik, U; Chen, C; Cochran, J; Prell, S; Ahmed, H; Gritsan, A V; Arnaud, N; Davier, M; Derkach, D; Grosdidier, G; Le Diberder, F; Lutz, A M; Malaescu, B; Roudeau, P; Stocchi, A; Wormser, G; Lange, D J; Wright, D M; Coleman, J P; Fry, J R; Gabathuler, E; Hutchcroft, D E; Payne, D J; Touramanis, C; Bevan, A J; Di Lodovico, F; Sacco, R; Cowan, G; Bougher, J; Brown, D N; Davis, C L; Denig, A G; Fritsch, M; Gradl, W; Griessinger, K; Hafner, A; Schubert, K R; Barlow, R J; Lafferty, G D; Cenci, R; Hamilton, B; Jawahery, A; Roberts, D A; Cowan, R; Sciolla, G; Cheaib, R; Patel, P M; Robertson, S H; Neri, N; Palombo, F; Cremaldi, L; Godang, R; Sonnek, P; Summers, D J; Simard, M; Taras, P; De Nardo, G; Onorato, G; Sciacca, C; Martinelli, M; Raven, G; Jessop, C P; LoSecco, J M; Honscheid, K; Kass, R; Feltresi, E; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simi, G; Simonetto, F; Stroili, R; Akar, S; Ben-Haim, E; Bomben, M; Bonneaud, G R; Briand, H; Calderini, G; Chauveau, J; Leruste, Ph; Marchiori, G; Ocariz, J; Biasini, M; Manoni, E; Pacetti, S; Rossi, A; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Casarosa, G; Cervelli, A; Chrzaszcz, M; Forti, F; Giorgi, M A; Lusiani, A; Oberhof, B; Paoloni, E; Perez, A; Rizzo, G; Walsh, J J; Lopes Pegna, D; Olsen, J; Smith, A J S; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Pilloni, A; Piredda, G; Bünger, C; Dittrich, S; Grünberg, O; Hartmann, T; Hess, M; Leddig, T; Voß, C; Waldi, R; Adye, T; Olaiya, E O; Wilson, F F; Emery, S; Vasseur, G; Anulli, F; Aston, D; Bard, D J; Cartaro, C; Convery, M R; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Ebert, M; Field, R C; Fulsom, B G; Graham, M T; Hast, C; Innes, W R; Kim, P; Leith, D W G S; Lewis, P; Lindemann, D; Luitz, S; Luth, V; Lynch, H L; MacFarlane, D B; Muller, D R; Neal, H; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Snyder, A; Su, D; Sullivan, M K; Va'vra, J; Wisniewski, W J; Wulsin, H W; Purohit, M V; White, R M; Wilson, J R; Randle-Conde, A; Sekula, S J; Bellis, M; Burchat, P R; Puccio, E M T; Alam, M S; Ernst, J A; Gorodeisky, R; Guttman, N; Peimer, D R; Soffer, A; Spanier, S M; Ritchie, J L; Ruland, A M; Schwitters, R F; Wray, B C; Izen, J M; Lou, X C; Bianchi, F; De Mori, F; Filippi, A; Gamba, D; Lanceri, L; Vitale, L; Martinez-Vidal, F; Oyanguren, A; Villanueva-Perez, P; Albert, J; Banerjee, Sw; Beaulieu, A; Bernlochner, F U; Choi, H H F; King, G J; Kowalewski, R; Lewczuk, M J; Lueck, T; Nugent, I M; Roney, J M; Sobie, R J; Tasneem, N; Gershon, T J; Harrison, P F; Latham, T E; Band, H R; Dasu, S; Pan, Y; Prepost, R; Wu, S L

    2014-11-14

    Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon (A^{'}), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e^{+}e^{-}→γA^{'}, A^{'}→e^{+}e^{-}, μ^{+}μ^{-} using 514  fb^{-1} of data collected with the BABAR detector. We observe no statistically significant deviations from the standard model predictions, and we set 90% confidence level upper limits on the mixing strength between the photon and dark photon at the level of 10^{-4}-10^{-3} for dark photon masses in the range 0.02-10.2  GeV. We further constrain the range of the parameter space favored by interpretations of the discrepancy between the calculated and measured anomalous magnetic moment of the muon.

  9. Superheavy Majorana neutrinos effect in the lepton-number violating e-+e--->μ- +μ- process

    NASA Astrophysics Data System (ADS)

    Pham, X. Y.

    2000-12-01

    In the minimal extension of the standard electroweak theory with ultra massive Majorana neutrinos, the process e-+e--->μ-+μ- could be observable, in sharp contrast with the reaction e-+e--->W-+W- which is entirely controlled by neutrinoless double beta decay ββ0ν data. Our result provides the process background that must be confronted ``new physics'' models which postulate doubly charged particles, such as the gauge bilepton Y-- in the SU(3)c×SU(3)L×U(1) model, the left-right SU(2)L×SU(2)R×U(1)B-L one, and its supersymmetric version with doubly charged Higgs multiplets.

  10. Beyond Higgs couplings: Probing the Higgs with angular observables at future e$^{+}$e$^{-}$ colliders

    SciTech Connect

    Craig, Nathaniel; Gu, Jiayin; Liu, Zhen; Wang, Kechen

    2016-03-09

    Here, we study angular observables in the $ {e}^{+}{e}^{-}\\to ZH\\to {\\ell}^{+}{\\ell}^{-}b\\overline{b} $ channel at future circular e$^{+}$ e$^{-}$ colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy $ \\sqrt{s}=240 $ GeV and 5 (30) ab$^{-1}$ integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for he Higgs-strahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of both probing BSM corrections to the HZγ coupling and constraining the “blind spot” in indirect limits on supersymmetric scalar top partners.

  11. Relating e+e- annihilation to high energy scattering at weak and strong coupling

    NASA Astrophysics Data System (ADS)

    Hatta, Yoshitaka

    2008-11-01

    We explore the correspondence between the final state in e+e- annihilation and the small-x hadronic wavefunction in the transverse plane both in weakly coupled QCD and strongly coupled Script N = 4 SYM. At strong coupling, the virtual and static photon produced in e+e- annihilation can be treated as a shock wave propagating in AdS space leaving spherical energy and charge distributions on the boundary. This is shown to be mathematically identical to the computation of energy and charge distributions in the transverse plane generated by a high energy color singlet state. At weak coupling, the correspondence is useful in studying interjet observables. By performing the stereographic projection to the BFKL equation, we construct an exact solution to the evolution equation derived by Marchesini and Mueller, and find the angular distribution of small-x gluons in the interjet region. Finally we argue that the correspondence holds also for the energy correlation functions.

  12. Study of baryon production mechanism in e+e- annihilation into hadrons

    NASA Astrophysics Data System (ADS)

    Topaz Collaboration; Aoki, M.; Itoh, R.; Watanabe, Y.; Kaneyuki, K.; Ohshima, Y.; Ochi, A.; Tanimori, T.; Abe, K.; Abe, T.; Adachi, I.; Adachi, K.; Aoki, M.; Emi, K.; Enomoto, R.; Fujii, H.; Fujii, T.; Fujii, K.; Fujimoto, J.; Fujiwara, N.; Hayashii, H.; Hirano, H.; Howell, B.; Ikeda, H.; Inoue, Y.; Itami, S.; Iwasaki, H.; Iwasaki, M.; Kajikawa, R.; Kato, S.; Kawabata, S.; Kichimi, H.; Kobayashi, M.; Koltick, D.; Levine, I.; Mamada, H.; Miyabayashi, K.; Miyamoto, A.; Nagai, K.; Nakabayashi, K.; Nakamura, M.; Nakano, E.; Nitoh, O.; Noguchi, S.; Ochiai, F.; Ohishi, N.; Ohnishi, Y.; Okuno, H.; Okusawa, T.; Shibata, E.; Sugiyama, A.; Suzuki, S.; Takahashi, K.; Takahashi, T.; Teramoto, Y.; Tauchi, T.; Tomoto, M.; Tsukamoto, T.; Tsumura, T.; Uno, S.; Yamamoto, A.; Yamauchi, M.

    1998-11-01

    The mechanism of baryon-anti-baryon pair production in e+e- annihilation into hadrons has been studied using the TOPAZ detector at the TRISTAN e+e- collider at an average center-of-mass energy of 58 GeV. The distributions of various p¯p correlations were compared with two prominent models: the cluster-fragmentation model and the string-fragmentation model. We rejected the cluster-fragmentation model at the 90% C.L. Furthermore, in the context of the string-fragmentation model, we favor the ``popcorn'' model, rejecting the ``diquark'' model, where a diquark is considered to be a fundamental entity, at the 95% C.L.

  13. Search for a Dark Photon in e+e- Collisions at BaBar

    NASA Astrophysics Data System (ADS)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Feng, M.; Kerth, L. T.; Kolomensky, Yu. G.; Lee, M. J.; Lynch, G.; Koch, H.; Schroeder, T.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Lankford, A. J.; Mandelkern, M.; Dey, B.; Gary, J. W.; Long, O.; Campagnari, C.; Franco Sevilla, M.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Lockman, W. S.; Panduro Vazquez, W.; Schumm, B. A.; Seiden, A.; Chao, D. S.; Cheng, C. H.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Miyashita, T. S.; Ongmongkolkul, P.; Porter, F. C.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Pushpawela, B. G.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Bernard, D.; Verderi, M.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Piemontese, L.; Santoro, V.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Martellotti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Adametz, A.; Uwer, U.; Lacker, H. M.; Dauncey, P. D.; Mallik, U.; Chen, C.; Cochran, J.; Prell, S.; Ahmed, H.; Gritsan, A. V.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Cowan, G.; Bougher, J.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Schubert, K. R.; Barlow, R. J.; Lafferty, G. D.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Cowan, R.; Sciolla, G.; Cheaib, R.; Patel, P. M.; Robertson, S. H.; Neri, N.; Palombo, F.; Cremaldi, L.; Godang, R.; Sonnek, P.; Summers, D. J.; Simard, M.; Taras, P.; De Nardo, G.; Onorato, G.; Sciacca, C.; Martinelli, M.; Raven, G.; Jessop, C. P.; LoSecco, J. M.; Honscheid, K.; Kass, R.; Feltresi, E.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Chrzaszcz, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Olsen, J.; Smith, A. J. S.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Pilloni, A.; Piredda, G.; Bünger, C.; Dittrich, S.; Grünberg, O.; Hartmann, T.; Hess, M.; Leddig, T.; Voß, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Vasseur, G.; Anulli, F.; Aston, D.; Bard, D. J.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Fulsom, B. G.; Graham, M. T.; Hast, C.; Innes, W. R.; Kim, P.; Leith, D. W. G. S.; Lewis, P.; Lindemann, D.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'vra, J.; Wisniewski, W. J.; Wulsin, H. W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Puccio, E. M. T.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Spanier, S. M.; Ritchie, J. L.; Ruland, A. M.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; De Mori, F.; Filippi, A.; Gamba, D.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P.; Albert, J.; Banerjee, Sw.; Beaulieu, A.; Bernlochner, F. U.; Choi, H. H. F.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Lueck, T.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.; Wu, S. L.; BaBar Collaboration

    2014-11-01

    Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon (A'), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e+e-→γ A' , A'→e+e- , μ+μ- using 514 fb-1 of data collected with the BABAR detector. We observe no statistically significant deviations from the standard model predictions, and we set 90% confidence level upper limits on the mixing strength between the photon and dark photon at the level of 1 0-4-1 0-3 for dark photon masses in the range 0.02 - 10.2 GeV . We further constrain the range of the parameter space favored by interpretations of the discrepancy between the calculated and measured anomalous magnetic moment of the muon.

  14. Effect of deformations and orientations in 100Sn daughter radioactivity

    NASA Astrophysics Data System (ADS)

    Sawhney, Gudveen; Sharma, Kanishka; Sharma, Manoj K.; Gupta, Raj K.

    2016-05-01

    Based on the preformed cluster model (PCM), we have extended our earlier study to investigate the effects of nuclear deformations and orientations of nuclei in context of ground-state de-excitation of Xe to Gd parents, resulting in a doubly closed shell 100Sn daughter and the complementary clusters. The comparison is also made with spherical choice of fragments to extract exclusive picture of the dynamics involved. Since PCM is based on collective clusterization picture, the preformation and penetration probabilities are shown to get modified considerably by inclusion of the quadrupole deformations (β2i) alone, which in turn affects the decay half-lives of the clusters.

  15. Photocopy of a photograph showing a woman (not E.E. Lape, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of a photograph showing a woman (not E.E. Lape, but possibly E.F. Read) seated outside of southwest corner of Murdock House (circa 1930s?). (Photo found in Lape-Read House, located at U.S. Fish and Wildlife Service - Murdock Hill, Murdock House, South side of Old Clinton Road (U.S. Route 1), 1 mile east of Horse Hill Road, Westbrook, Middlesex County, CT

  16. Evidence of Two Resonant Structures in e^{+}e^{-}→π^{+}π^{-}h_{c}.

    PubMed

    Ablikim, M; Achasov, M N; Ahmed, S; Ai, X C; Albayrak, O; Albrecht, M; Ambrose, D J; Amoroso, A; An, F F; An, Q; Bai, J Z; Bakina, O; Baldini Ferroli, R; Ban, Y; Bennett, D W; Bennett, J V; Berger, N; Bertani, M; Bettoni, D; Bian, J M; Bianchi, F; Boger, E; Boyko, I; Briere, R A; Cai, H; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chai, J; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, J C; Chen, M L; Chen, S; Chen, S J; Chen, X; Chen, X R; Chen, Y B; Chu, X K; Cibinetto, G; Dai, H L; Dai, J P; Dbeyssi, A; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; De Mori, F; Ding, Y; Dong, C; Dong, J; Dong, L Y; Dong, M Y; Dou, Z L; Du, S X; Duan, P F; Fan, J Z; Fang, J; Fang, S S; Fang, X; Fang, Y; Farinelli, R; Fava, L; Feldbauer, F; Felici, G; Feng, C Q; Fioravanti, E; Fritsch, M; Fu, C D; Gao, Q; Gao, X L; Gao, Y; Gao, Z; Garzia, I; Goetzen, K; Gong, L; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, R P; Guo, Y; Guo, Y P; Haddadi, Z; Hafner, A; Han, S; Hao, X Q; Harris, F A; He, K L; Heinsius, F H; Held, T; Heng, Y K; Holtmann, T; Hou, Z L; Hu, C; Hu, H M; Hu, J F; Hu, T; Hu, Y; Huang, G S; Huang, J S; Huang, X T; Huang, X Z; Huang, Z L; Hussain, T; Ikegami Andersson, W; Ji, Q; Ji, Q P; Ji, X B; Ji, X L; Jiang, L W; Jiang, X S; Jiang, X Y; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Johansson, T; Julin, A; Kalantar-Nayestanaki, N; Kang, X L; Kang, X S; Kavatsyuk, M; Ke, B C; Kiese, P; Kliemt, R; Kloss, B; Kolcu, O B; Kopf, B; Kornicer, M; Kupsc, A; Kühn, W; Lange, J S; Lara, M; Larin, P; Lavezzi, L; Leithoff, H; Leng, C; Li, C; Li, Cheng; Li, D M; Li, F; Li, F Y; Li, G; Li, H B; Li, H J; Li, J C; Li, Jin; Li, K; Li, K; Li, Lei; Li, P R; Li, Q Y; Li, T; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, Y B; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Lin, D X; Liu, B; Liu, B J; Liu, C X; Liu, D; Liu, F H; Liu, Fang; Liu, Feng; Liu, H B; Liu, H H; Liu, H H; Liu, H M; Liu, J; Liu, J B; Liu, J P; Liu, J Y; Liu, K; Liu, K Y; Liu, L D; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, Y B; Liu, Y Y; Liu, Z A; Liu, Zhiqing; Loehner, H; Lou, X C; Lu, H J; Lu, J G; Lu, Y; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lyu, X R; Ma, F C; Ma, H L; Ma, L L; Ma, M M; Ma, Q M; Ma, T; Ma, X N; Ma, X Y; Ma, Y M; Maas, F E; Maggiora, M; Malik, Q A; Mao, Y J; Mao, Z P; Marcello, S; Messchendorp, J G; Mezzadri, G; Min, J; Min, T J; Mitchell, R E; Mo, X H; Mo, Y J; Morales Morales, C; Muchnoi, N Yu; Muramatsu, H; Musiol, P; Nefedov, Y; Nerling, F; Nikolaev, I B; Ning, Z; Nisar, S; Niu, S L; Niu, X Y; Olsen, S L; Ouyang, Q; Pacetti, S; Pan, Y; Patteri, P; Pelizaeus, M; Peng, H P; Peters, K; Pettersson, J; Ping, J L; Ping, R G; Poling, R; Prasad, V; Qi, H R; Qi, M; Qian, S; Qiao, C F; Qin, L Q; Qin, N; Qin, X S; Qin, Z H; Qiu, J F; Rashid, K H; Redmer, C F; Ripka, M; Rong, G; Rosner, Ch; Ruan, X D; Sarantsev, A; Savrié, M; Schnier, C; Schoenning, K; Shan, W; Shao, M; Shen, C P; Shen, P X; Shen, X Y; Sheng, H Y; Song, W M; Song, X Y; Sosio, S; Spataro, S; Sun, G X; Sun, J F; Sun, S S; Sun, X H; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Tiemens, M; Uman, I; Varner, G S; Wang, B; Wang, B L; Wang, D; Wang, D Y; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, W; Wang, W P; Wang, X F; Wang, Y; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z H; Wang, Z Y; Wang, Z Y; Weber, T; Wei, D H; Weidenkaff, P; Wen, S P; Wiedner, U; Wolke, M; Wu, L H; Wu, L J; Wu, Z; Xia, L; Xia, L G; Xia, Y; Xiao, D; Xiao, H; Xiao, Z J; Xie, Y G; Xie, Yuehong; Xiu, Q L; Xu, G F; Xu, J J; Xu, L; Xu, Q J; Xu, Q N; Xu, X P; Yan, L; Yan, W B; Yan, W C; Yan, Y H; Yang, H J; Yang, H X; Yang, L; Yang, Y X; Ye, M; Ye, M H; Yin, J H; You, Z Y; Yu, B X; Yu, C X; Yu, J S; Yuan, C Z; Yuan, Y; Yuncu, A; Zafar, A A; Zeng, Y; Zeng, Z; Zhang, B X; Zhang, B Y; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J; Zhang, J J; Zhang, J L; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, K; Zhang, L; Zhang, S Q; Zhang, X Y; Zhang, Y; Zhang, Y; Zhang, Y H; Zhang, Y N; Zhang, Y T; Zhang, Yu; Zhang, Z H; Zhang, Z P; Zhang, Z Y; Zhao, G; Zhao, J W; Zhao, J Y; Zhao, J Z; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, Q W; Zhao, S J; Zhao, T C; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, W J; Zheng, Y H; Zhong, B; Zhou, L; Zhou, X; Zhou, X K; Zhou, X R; Zhou, X Y; Zhu, K; Zhu, K J; Zhu, S; Zhu, S H; Zhu, X L; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, J; Zotti, L; Zou, B S; Zou, J H

    2017-03-03

    The cross sections of e^{+}e^{-}→π^{+}π^{-}h_{c} at center-of-mass energies from 3.896 to 4.600 GeV are measured using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The cross sections are found to be of the same order of magnitude as those of e^{+}e^{-}→π^{+}π^{-}J/ψ and e^{+}e^{-}→π^{+}π^{-}ψ(2S), but the line shape is inconsistent with the Y states observed in the latter two modes. Two structures are observed in the e^{+}e^{-}→π^{+}π^{-}h_{c} cross sections around 4.22 and 4.39  GeV/c^{2}, which we call Y(4220) and Y(4390), respectively. A fit with a coherent sum of two Breit-Wigner functions results in a mass of (4218.4_{-4.5}^{+5.5}±0.9)  MeV/c^{2} and a width of (66.0_{-8.3}^{+12.3}±0.4)  MeV for the Y(4220), and a mass of (4391.5_{-6.8}^{+6.3}±1.0)  MeV/c^{2} and a width of (139.5_{-20.6}^{+16.2}±0.6)  MeV for the Y(4390), where the first uncertainties are statistical and the second ones systematic. The statistical significance of Y(4220) and Y(4390) is 10σ over one structure assumption.

  17. Extracting the kaon Collins function from e+e- hadron pair production data

    NASA Astrophysics Data System (ADS)

    Anselmino, M.; Boglione, M.; D'Alesio, U.; Hernandez, J. O. Gonzalez; Melis, S.; Murgia, F.; Prokudin, A.

    2016-02-01

    The latest data released by the BABAR Collaboration on azimuthal correlations measured for pion-kaon and kaon-kaon pairs produced in e+e- annihilations allow, for the first time, a direct extraction of the kaon Collins functions. These functions are then used to compute the kaon Collins asymmetries in semi-inclusive deep inelastic scattering processes, which result in good agreement with the measurements performed by the HERMES and COMPASS collaborations.

  18. Measurements of the Collins asymmetries for kaons and pions in e+e- annihilations at BABAR

    NASA Astrophysics Data System (ADS)

    Filippi, A.

    2016-07-01

    New measurements of the Collins asymmetries were performed by BABAR exploiting inclusive e+e- → h1h2 X annihilations (with h1,2 = π and/or K) mainly at the energy of the ϒ(4S), which corresponds to a squared transferred momentum Q2 ~ 110 GeV2c4. For the first time asymmetries following strange quarks fragmentation could be derived as a function of the fractional energy carried out by inclusively emitted hadron pairs.

  19. Sex Pheromones: (E,E)-8,10-Dodecadien-1-ol in the Codling Moth.

    PubMed

    Beroza, M; Bierl, B A; Moffitt, H R

    1974-01-11

    Although (E,E)-8,10-Dodecadien-l-ol was reported to be a sex pheromone of the codling moth [Laspeyresia pomonella (L.)], its presence in the moth was questioned, mainly because it has not been isolated. A computerized search of data from gas chromatography-mass spectrometry of a partially purified extract equivalent to 45 abdominal tips of female moths produced a mass spectrum that matched that of the authentic coinpound. Other data also confirmed the presence of the compound.

  20. Structural and theoretical studies of (E,E)-benzaldehyde azine and its rhenium(IV) complex

    NASA Astrophysics Data System (ADS)

    Pintos, V.; Cuevas, A.; Onetto, S.; Seoane, G.; Denis, P. A.; Gancheff, J. S.; Faccio, R.; Mombrú, A. W.; Kremer, C.

    2010-01-01

    The azine bridged dicatechol ligand (E,E)-benzaldehyde azine (H 4L) was fully characterized by X-ray analysis. The reaction of [ReCl 6] 2- with this compound was studied and the novel Re(IV) complex (HNEt 3)(NBu 4)[ReCl 4(H 2L)] was prepared and characterized. The structure and spectroscopy of the compound H 4L and its Re(IV) complex were studied experimentally and by means of density functional calculations.

  1. Four-Quasiparticle High-K States in Neutron-Deficient Lead and Polonium Nuclei

    NASA Astrophysics Data System (ADS)

    Shi, Yue; Xu, Furong

    2012-06-01

    Configuration-constrained potential energy surface calculations have been performed to investigate four-quasiparticle high-K configurations in neutron-deficient lead and polonium isotopes. A good agreement between the calculations and the experimental data has been found for the excitation energy of the observed Kπ = 19- state in 188Pb. Several lowly excited high-K states are predicted, and the large oblate deformation and low energy indicate high-K isomerism in these nuclei.

  2. Theoretical study of triaxial shapes of neutron-rich Mo and Ru nuclei

    DOE PAGES

    Zhang, C. L.; Bhat, G. H.; Nazarewicz, W.; ...

    2015-09-10

    Here, whether atomic nuclei can possess triaxial shapes at their ground states is still a subject of ongoing debate. According to theory, good prospects for low-spin triaxiality are in the neutron-rich Mo-Ru region. Recently, transition quadrupole moments in rotational bands of even-mass neutron-rich isotopes of molybdenum and ruthenium nuclei have been measured. The new data have provided a challenge for theoretical descriptions invoking stable triaxial deformations. The purpose of this study is to understand experimental data on rotational bands in the neutron-rich Mo-Ru region, we carried out theoretical analysis of moments of inertia, shapes, and transition quadrupole moments of neutron-richmore » even-even nuclei around 110Ru using self-consistent mean-field and shell model techniques. Methods: To describe yrast structures in Mo and Ru isotopes, we use nuclear density functional theory (DFT) with the optimized energy density functional UNEDF0. We also apply triaxial projected shell model (TPSM) to describe yrast and positive-parity, near-yrast band structures. As a result, our self-consistent DFT calculations predict triaxial ground-state deformations in 106,108Mo and 108,110,112Ru and reproduce the observed low-frequency behavior of moments of inertia. As the rotational frequency increases, a negative-gamma structure, associated with the aligned ν(h11/2)2 pair, becomes energetically favored. The computed transition quadrupole moments vary with angular momentum, which reflects deformation changes with rotation; those variations are consistent with experiment. The TPSM calculations explain the observed band structures assuming stable triaxial shapes. Lastly, the structure of neutron-rich even-even nuclei around Ru-110 is consistent with triaxial shape deformations. Our DFT and TPSM frameworks provide a consistent and complementary description of experimental data.« less

  3. Theoretical study of triaxial shapes of neutron-rich Mo and Ru nuclei

    SciTech Connect

    Zhang, C. L.; Bhat, G. H.; Nazarewicz, W.; Sheikh, J. A.; Shi, Yue

    2015-09-10

    Here, whether atomic nuclei can possess triaxial shapes at their ground states is still a subject of ongoing debate. According to theory, good prospects for low-spin triaxiality are in the neutron-rich Mo-Ru region. Recently, transition quadrupole moments in rotational bands of even-mass neutron-rich isotopes of molybdenum and ruthenium nuclei have been measured. The new data have provided a challenge for theoretical descriptions invoking stable triaxial deformations. The purpose of this study is to understand experimental data on rotational bands in the neutron-rich Mo-Ru region, we carried out theoretical analysis of moments of inertia, shapes, and transition quadrupole moments of neutron-rich even-even nuclei around 110Ru using self-consistent mean-field and shell model techniques. Methods: To describe yrast structures in Mo and Ru isotopes, we use nuclear density functional theory (DFT) with the optimized energy density functional UNEDF0. We also apply triaxial projected shell model (TPSM) to describe yrast and positive-parity, near-yrast band structures. As a result, our self-consistent DFT calculations predict triaxial ground-state deformations in 106,108Mo and 108,110,112Ru and reproduce the observed low-frequency behavior of moments of inertia. As the rotational frequency increases, a negative-gamma structure, associated with the aligned ν(h11/2)2 pair, becomes energetically favored. The computed transition quadrupole moments vary with angular momentum, which reflects deformation changes with rotation; those variations are consistent with experiment. The TPSM calculations explain the observed band structures assuming stable triaxial shapes. Lastly, the structure of neutron-rich even-even nuclei around Ru-110 is consistent with triaxial shape deformations. Our DFT and TPSM frameworks provide a consistent and complementary description of experimental data.

  4. Deformations of superconformal theories

    NASA Astrophysics Data System (ADS)

    Córdova, Clay; Dumitrescu, Thomas T.; Intriligator, Kenneth

    2016-11-01

    We classify possible supersymmetry-preserving relevant, marginal, and irrelevant deformations of unitary superconformal theories in d ≥ 3 dimensions. Our method only relies on symmetries and unitarity. Hence, the results are model independent and do not require a Lagrangian description. Two unifying themes emerge: first, many theories admit deformations that reside in multiplets together with conserved currents. Such deformations can lead to modifications of the supersymmetry algebra by central and non-central charges. Second, many theories with a sufficient amount of supersymmetry do not admit relevant or marginal deformations, and some admit neither. The classification is complicated by the fact that short superconformal multiplets display a rich variety of sporadic phenomena, including supersymmetric deformations that reside in the middle of a multiplet. We illustrate our results with examples in diverse dimensions. In particular, we explain how the classification of irrelevant supersymmetric deformations can be used to derive known and new constraints on moduli-space effective actions.

  5. Deformations of superconformal theories

    SciTech Connect

    Córdova, Clay; Dumitrescu, Thomas T.; Intriligator, Kenneth

    2016-11-22

    Here, we classify possible supersymmetry-preserving relevant, marginal, and irrelevant deformations of unitary superconformal theories in d ≥ 3 dimensions. Our method only relies on symmetries and unitarity. Hence, the results are model independent and do not require a Lagrangian description. Two unifying themes emerge: first, many theories admit deformations that reside in multiplets together with conserved currents. Such deformations can lead to modifications of the supersymmetry algebra by central and noncentral charges. Second, many theories with a sufficient amount of supersymmetry do not admit relevant or marginal deformations, and some admit neither. The classification is complicated by the fact that short superconformal multiplets display a rich variety of sporadic phenomena, including supersymmetric deformations that reside in the middle of a multiplet. We illustrate our results with examples in diverse dimensions. In particular, we explain how the classification of irrelevant supersymmetric deformations can be used to derive known and new constraints on moduli-space effective actions.

  6. Characterizing invisible electroweak particles through single-photon processes at high energy e+e- colliders

    NASA Astrophysics Data System (ADS)

    Choi, Seong Youl; Han, Tao; Kalinowski, Jan; Rolbiecki, Krzysztof; Wang, Xing

    2015-11-01

    We explore the scenarios where the only accessible new states at the electroweak scale consist of a pair of color-singlet electroweak particles, the masses of which are degenerate at the tree level and split only by electroweak symmetry breaking at the loop level. For the sake of illustration, we consider a supersymmetric model and study the following three representative cases with the lower-lying states as (a) two spin-1 /2 Higgsino SU(2 ) L doublets, (b) a spin-1 /2 wino SU(2 ) L triplet and (c) a spin-0 left-handed slepton SU(2 ) L doublet. Due to the mass degeneracy, those lower-lying electroweak states are difficult to observe at the LHC and rather challenging to detect at the e+e- collider as well. We exploit the pair production in association with a hard photon radiation in high energy e+e- collisions. If kinematically accessible, such single-photon processes at e+e- colliders with polarized beams enable us to characterize each scenario by measuring the energy of the associated hard photon and to determine the spin of the nearly invisible particles unambiguously through the threshold behavior in the photon energy distribution.

  7. RBE estimation of proton radiation fields using a ΔE-E telescope.

    PubMed

    Wroe, Andrew; Schulte, Reinhard; Fazzi, Alberto; Pola, Andrea; Agosteo, Stefano; Rosenfeld, Anatoly

    2009-10-01

    A new monolithic silicon ΔE-E telescope was evaluated in unmodulated and modulated 100 MeV proton beams used for hadron therapy. Compared to a classical microdosimetry detector, which provides one-dimensional information on lineal energy of charged particles, this detector system provides two-dimensional information on lineal energy and particle energy based on energy depositions, collected in coincidence, within the ΔE and E stages of the detector. The authors investigated the possibility to use the information obtained with the ΔE-E telescope to determine the relative biological effectiveness (RBE) at defined locations within the proton Bragg peak and spread-out Bragg peak (SOBP). An RBE matrix based on the established in vitro V79 cell survival data was developed to link the output of the device directly to RBE(α), the RBE in the low-dose limit, at various depths in a homogeneous polystyrene phantom. In the SOBP of a 100 MeV proton beam, the RBE(α) increased from 4.04 proximal to the SOBP to a maximum value of 5.4 at the distal edge. The ΔE-E telescope, with its high spatial resolution, has potential applications to biologically weighted hadron treatment planning as it provides a compact and portable means for estimating the RBE in rapidly changing hadron radiation fields within phantoms. © 2009 American Association of Physicists in Medicine.

  8. Detection of heavy charged Higgs bosonsin e+ e- -> t b H- production at future Linear Colliders

    NASA Astrophysics Data System (ADS)

    Moretti, S.

    2004-05-01

    Heavy charged Higgs bosons (H^±) of a Type II 2-Higgs doublet model (2HDM) can be detected at future electron-positron Linear Colliders (LCs) even when their mass is larger than half the collider energy. The single Higgs mode e^ + e^-to tbar b H^- + {c.c.} to 4b + {j}{j} + ell + pT^{miss} (where j represents a jet and with ell = e,μ) contributes to extend the discovery reach of H^± states into the mass region M_{H^±}gtrsim sqrt s/2, where the well studied pair production channel e^ + e^-to H^-H^ + is no longer available. With a technique that allows one to reconstruct the neutrino four-momentum in the decay tto b W^ + to b ell^ + ν, one can suppress the initially overwhelming main irreducible background due to e^ + e^-to tbar t bbar b (via a gluon splitting into bbar b pairs) to a negligible level. However, for currently foreseen luminosities, one can establish a statistically significant H^± signal only over a rather limited mass region, of 20 GeV or so, beyond M_{H^±}≈ sqrt s/2, for very large or very small values of tanβ and provided high b-tagging efficiency can be achieved.

  9. Search for Long-Lived Particles in e+e- Collisions

    NASA Astrophysics Data System (ADS)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lee, M. J.; Lynch, G.; Koch, H.; Schroeder, T.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Lankford, A. J.; Dey, B.; Gary, J. W.; Long, O.; Campagnari, C.; Franco Sevilla, M.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Lockman, W. S.; Panduro Vazquez, W.; Schumm, B. A.; Seiden, A.; Chao, D. S.; Cheng, C. H.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Miyashita, T. S.; Ongmongkolkul, P.; Porter, F. C.; Röhrken, M.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Pushpawela, B. G.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Bernard, D.; Verderi, M.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Piemontese, L.; Santoro, V.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Martellotti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Adametz, A.; Uwer, U.; Lacker, H. M.; Mallik, U.; Chen, C.; Cochran, J.; Prell, S.; Ahmed, H.; Gritsan, A. V.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; di Lodovico, F.; Sacco, R.; Cowan, G.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Schubert, K. R.; Barlow, R. J.; Lafferty, G. D.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Cowan, R.; Sciolla, G.; Cheaib, R.; Patel, P. M.; Robertson, S. H.; Neri, N.; Palombo, F.; Cremaldi, L.; Godang, R.; Sonnek, P.; Summers, D. J.; Simard, M.; Taras, P.; de Nardo, G.; Onorato, G.; Sciacca, C.; Martinelli, M.; Raven, G.; Jessop, C. P.; Losecco, J. M.; Honscheid, K.; Kass, R.; Feltresi, E.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Chrzaszcz, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Olsen, J.; Smith, A. J. S.; Anulli, F.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Pilloni, A.; Piredda, G.; Bünger, C.; Dittrich, S.; Grünberg, O.; Hess, M.; Leddig, T.; Voß, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Vasseur, G.; Aston, D.; Bard, D. J.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Fulsom, B. G.; Graham, M. T.; Hast, C.; Innes, W. R.; Kim, P.; Leith, D. W. G. S.; Lindemann, D.; Luitz, S.; Luth, V.; Lynch, H. L.; Macfarlane, D. B.; Muller, D. R.; Neal, H.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'Vra, J.; Wisniewski, W. J.; Wulsin, H. W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Puccio, E. M. T.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Spanier, S. M.; Ritchie, J. L.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; de Mori, F.; Filippi, A.; Gamba, D.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P.; Albert, J.; Banerjee, Sw.; Beaulieu, A.; Bernlochner, F. U.; Choi, H. H. F.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Lueck, T.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.; Wu, S. L.; Babar Collaboration

    2015-05-01

    We present a search for a neutral, long-lived particle L that is produced in e+e- collisions and decays at a significant distance from the e+e- interaction point into various flavor combinations of two oppositely charged tracks. The analysis uses an e+e- data sample with a luminosity of 489.1 fb-1 collected by the BABAR detector at the ϒ (4 S ) , ϒ (3 S ) , and ϒ (2 S ) resonances and just below the ϒ (4 S ) . Fitting the two-track mass distribution in search of a signal peak, we do not observe a significant signal, and set 90% confidence level upper limits on the product of the L production cross section, branching fraction, and reconstruction efficiency for six possible two-body L decay modes as a function of the L mass. The efficiency is given for each final state as a function of the mass, lifetime, and transverse momentum of the candidate, allowing application of the upper limits to any production model. In addition, upper limits are provided on the branching fraction B (B →XsL ) , where Xs is a strange hadronic system.

  10. Measurement of the e+e-→ω η cross section below √{s }=2 GeV

    NASA Astrophysics Data System (ADS)

    Achasov, M. N.; Barnyakov, A. Yu.; Beloborodov, K. I.; Berdyugin, A. V.; Bogdanchikov, A. G.; Botov, A. A.; Dimova, T. V.; Druzhinin, V. P.; Golubev, V. B.; Kardapoltsev, L. V.; Kasaev, A. S.; Kharlamov, A. G.; Kirpotin, A. N.; Kovrizhin, D. P.; Koop, I. A.; Korol, A. A.; Koshuba, S. V.; Kupich, A. S.; Martin, K. A.; Melnikova, N. A.; Obrazovsky, A. E.; Pakhtusova, E. V.; Senchenko, A. I.; Serednyakov, S. I.; Silagadze, Z. K.; Shatunov, Yu. M.; Shtol, D. A.; Shwartz, D. B.; Skrinsky, A. N.; Surin, I. K.; Tikhonov, Yu. A.; Vasiljev, A. V.

    2016-11-01

    The cross section of the process e+e-→ω η is measured in the center-of-mass energy range 1.34-2.00 GeV. The analysis is based on data collected with the SND detector at the VEPP-2000 e+e- collider. The measured e+e-→ω η cross section is the most accurate to date. A significant discrepancy is observed between our data and previous BABAR measurements.

  11. Effects of thermal shape fluctuations and pairing fluctuations on the giant dipole resonance in warm nuclei

    NASA Astrophysics Data System (ADS)

    Rhine Kumar, A. K.; Arumugam, P.; Dang, N. Dinh

    2015-04-01

    Apart from the higher limits of isospin and temperature, the properties of atomic nuclei are intriguing and less explored at the limits of lowest but finite temperatures. At very low temperatures there is a strong interplay between the shell (quantal fluctuations), statistical (thermal fluctuations), and residual pairing effects as evidenced from the studies on giant dipole resonance (GDR). In our recent work [Phys. Rev. C 90, 044308 (2014), 10.1103/PhysRevC.90.044308], we have outlined some of our results from a theoretical approach for such warm nuclei where all these effects are incorporated along within the thermal shape fluctuation model (TSFM) extended to include the fluctuations in the pairing field. In this article, we present the complete formalism based on the microscopic-macroscopic approach for determining the deformation energies and a macroscopic approach which links the deformation to GDR observables. We discuss our results for the nuclei 97Tc,120Sn,179Au, and 208Pb, and corroborate with the experimental data available. The TSFM could explain the data successfully at low temperature only with a proper treatment of pairing and its fluctuations. More measurements with better precision could yield rich information about several phase transitions that can happen in warm nuclei.

  12. Alar Rim Deformities.

    PubMed

    Totonchi, Ali; Guyuron, Bahman

    2016-01-01

    The alar rim plays an important role in nasal harmony. Alar rim flaws are common following the initial rhinoplasty. Classification of the deformities helps with diagnosis and successful surgical correction. Diagnosis of the deformity requires careful observation of the computerized or life-sized photographs. Techniques for treatment of these deformities can easily be learned with attention to detail. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Survey of odd-odd deformed nuclear spectroscopy

    SciTech Connect

    Hoff, R.W.

    1993-09-14

    In this paper, we survey the current experimental data that support assignment of rotational bands in odd-odd deformed nuclear in the rare earth and actinide regions. We present the results of a new study of {sup 170}Mt nuclear structure. In a comparing experimental and calculated Gallagher-Moszkowski matrix elements for rare earth-region nuclei, we have developed a new approach to the systematics of these matrix elements.

  14. Symmetry energy and surface properties of neutron-rich exotic nuclei

    SciTech Connect

    Gaidarov, M. K.; Antonov, A. N.; Sarriguren, P.; Moya de Guerra, E.

    2014-07-23

    The symmetry energy, the neutron pressure and the asymmetric compressibility of spherical Ni, Sn, and Pb and deformed Kr and Sm neutron-rich even-even nuclei are calculated within the coherent density fluctuation model using the symmetry energy as a function of density within the Brueckner energy-density functional. The correlation between the thickness of the neutron skin and the characteristics related with the density dependence of the nuclear symmetry energy is investigated for isotopic chains of these nuclei in the framework of the deformed self-consistent mean-field Skyrme HF+BCS method. The mass dependence of the nuclear symmetry energy and the neutron skin thickness are also studied together with the role of the neutron-proton asymmetry. The studied correlations reveal a smoother behavior in the case of spherical nuclei than for deformed ones. We also notice that the neutron skin thickness obtained for {sup 208}Pb with SLy4 force is found to be in a good agreement with the recent data. In addition to the interest that this study may have by itself, we give some numerical arguments in proof of the existence of peculiarities of the studied quantities in Ni and Sn isotopic chains that are not present in the Pb chain.

  15. Covariant density functional theory: Global performance and rotating nuclei

    NASA Astrophysics Data System (ADS)

    Ray, Debisree

    Covariant density functional theory (CDFT) is a modern theoretical tool for the description of nuclear structure physics. Here different physical properties of the ground and excited states in atomic nuclei have been investigated within the CDFT framework employing three major classes of the state-of-the-art covariant energy density functionals. The global performance of CEDFs for even-even nuclei are investigated and the systematic theoretical uncertainties are estimated within the set of four CEDFs in known regions of the nuclear chart and their propagation towards the neutron drip line. Large-scale axial relativistic Hartree-Bogoliubov (RHB) calculations are performed for even-even nuclei to calculate different ground state observables. The predictions for the two-neutron drip line are also compared in a systematic way with the non-relativistic results. CDFT has been applied for systematic study of extremely deformed, rotating N ˜ Z nuclei of the A ˜ 40 mass region. At spin zero such structures are located at high energies which prevents their experimental observation. The rotation acts as a tool to bring these exotic shapes down to the yrast line so that their observation could become possible with a future generation detectors such as GRETA or AGATA. The major physical observables of such structures, the underlying single-particle structure and the spins at which they become yrast or near yrast are defined. The search for the fingerprints of clusterization and molecular structures is performed and the configurations with such features are discussed. CDFT has been applied to study fission barriers of superheavy nuclei and related systematic theoretical uncertainties in the predictions of inner fission barrier heights in super- heavy elements. Systematic uncertainties are substantial in superheavy elements and their behavior as a function of proton and neutron numbers contains a large random component. The benchmarking of the functionals to the experimental

  16. Single Pion production from Nuclei

    SciTech Connect

    Singh, S. K.; Athar, M. Sajjad; Ahmed, S.

    2007-12-21

    We have studied charged current one pion production induced by {nu}{sub {mu}}({nu}-bar{sub {mu}}) from some nuclei. The calculations have been done for the incoherent pion production processes from these nuclear targets in the {delta} dominance model and take into account the effect of Pauli blocking, Fermi motion and renormalization of {delta} properties in the nuclear medium. The effect of final state interactions of pions has also been taken into account. The numerical results have been compared with the recent results from the MiniBooNE experiment for the charged current 1{pi} production, and also with some of the older experiments in Freon and Freon-Propane from CERN.

  17. The Physics of Cometary Nuclei

    NASA Technical Reports Server (NTRS)

    Whipple, Fred L.

    1997-01-01

    The recent developments in cometary studies suggest rather low mean densities and weak structures for the nuclei. They appear to be accumulations of fairly discrete units loosely bound together, as deduced from the observations of Comet Shoemaker-Levy 9 during its encounter with Jupiter. The compressive strengths deduced from comet splitting by Opik and Sekanina are extremely low. These values are confirmed by theory developed here. assuming that Comet P/Holmes had a companion that collided with it in 1892. There follows a short discussion that suggests that the mean densities of comets should increase with comet dimensions. The place of origin of short-period comets may relate to these properties.

  18. Inclusive breakup of Borromean nuclei

    NASA Astrophysics Data System (ADS)

    Hussein, M. S.; Carlson, B. V.; Frederico, T.

    2017-06-01

    We derive the inclusive breakup cross section of a three-fragment projectile nuclei, a = b + x 1 +x 2, in the spectator model. The resulting four-body cross section for observing b, is composed of the elastic breakup cross section which contains information about the correlation between the two participant fragments, and the inclusive non-elastic breakup cross section. This latter cross section is found to be a non-trivial four-body generalization of the Austern formula [1], which is proportional to a matrix element of the form, . The new feature here is the three-body absorption, represented by the imaginary potential, W 3b . We analyze this type of absorption and supply ideas of how to calculate its contribution.

  19. Breakup Densities of Hot Nuclei.

    NASA Astrophysics Data System (ADS)

    Viola, Vic

    2006-04-01

    Breakup densities of hot ^197Au-like residues have been deduced from the systematic trends of Coulomb parameters required to fit intermediate-mass-fragment kinetic-energy spectra. The results indicate emission from nuclei near normal nuclear density below an excitation energy E*/A .3ex<˜x 2 MeV, followed by a gradual decrease to a near-constant value of ρ/ρ0˜ 3 for E*/A .3ex>˜x 5 MeV. Temperatures derived from these data with a density-dependent Fermi-gas model yield a nuclear caloric curve that is generally consistent with those derived from isotope ratios.

  20. Quasifree kaon photoproduction on nuclei

    SciTech Connect

    Frank Lee; T. MART; Cornelius Bennhold; Lester Wright

    2001-12-01

    Investigations of the quasifree reaction A({gamma}, K Y)B are presented in the distorted wave impulse approximation (DWIA). For this purpose, we present a revised tree-level model of elementary kaon photoproduction that incorporates hadronic form factors consistent with gauge invariance, uses SU(3) values for the Born couplings and uses resonances consistent with multi-channel analyses. The potential of exclusive quasifree kaon photoproduction on nuclei to reveal details of the hyperon-nucleus interaction is examined. Detailed predictions for the coincidence cross section, the photon asymmetry, and the hyperon polarization and their sensitivities to the ingredients of the model are obtained for all six production channels. Under selected kinematics these observables are found to be sensitive to the hyperon-nucleus final state interaction. Some polarization observables are found to be insensitive to distortion effects, making them ideal tools to search for possible medium modifications of the elementary amplitude.

  1. Reaction theory for exotic nuclei

    SciTech Connect

    Bonaccorso, Angela

    2014-05-09

    Exotic nuclei are usually defined as those with unusual N/Z ratios. They can be found in the crust of neutron stars enbedded in a sea of electrons or created in laboratory by fragmentation of a primary beam (in-flight method) or of the target (ISOL method). They are extremely important for nuclear astrophysics, see for example Ref.[1]. Furthermore by studying them we can check the limits of validity of nuclear reaction and structure models. This contribution will be devoted to the understanding of how by using reaction theory and comparing to the data we can extract structure information. We shall discuss the differences between the mechanisms of transfer and breakup reactions, an we will try to explain how nowadays it is possible to do accurate spectroscopy in extreme conditions.

  2. Observation of nuclear scaling in the A(e,e') reaction at xB>1

    NASA Astrophysics Data System (ADS)

    Egiyan, K.; Dashyan, N.; Sargsian, M.; Stepanyan, S.; Weinstein, L.; Adams, G.; Ambrozewicz, P.; Anciant, E.; Anghinolfi, M.; Asavapibhop, B.; Asryan, G.; Audit, G.; Auger, T.; Avakian, H.; Bagdasaryan, H.; Ball, J.; Barrow, S.; Battaglieri, M.; Beard, K.; Bedlinski, I.; Bektasoglu, M.; Bellis, M.; Benmouna, N.; Bianchi, N.; Biselli, A.; Boiarinov, S.; Bonner, B.; Bouchigny, S.; Bradford, R.; Branford, D.; Briscoe, W.; Brooks, W.; Burkert, V.; Butuceanu, C.; Calarco, J.; Carman, D.; Carnahan, B.; Cetina, C.; Ciciani, L.; Cole, P.; Coleman, A.; Cords, D.; Connelly, J.; Corvisiero, P.; Crabb, D.; Crannell, H.; Cummings, J.; Desanctis, E.; Devita, R.; Degtyarenko, P.; Demirchyan, R.; Denizli, H.; Dennis, L.; Dharmawardane, K.; Dhuga, K.; Djalali, C.; Dodge, G.; Doughty, D.; Dragovitsch, P.; Dugger, M.; Dytman, S.; Dzyubak, O.; Eckhause, M.; Egiyan, H.; Elouadrhiri, L.; Empl, A.; Eugenio, P.; Fatemi, R.; Feuerbach, R.; Ficenec, J.; Forest, T.; Funsten, H.; Gai, M.; Gavalian, G.; Gilad, S.; Gilfoyle, G.; Giovanetti, K.; Girard, P.; Gordon, C.; Griffioen, K.; Guidal, M.; Guillo, M.; Guo, L.; Gyurjyan, V.; Hadjidakis, C.; Hakobyan, R.; Hardie, J.; Heddle, D.; Heimberg, P.; Hersman, F.; Hicks, K.; Hicks, R.; Holtrop, M.; Hu, J.; Hyde-Wright, C.; Ilieva, Y.; Ito, M.; Jenkins, D.; Joo, K.; Kelley, J.; Khandaker, M.; Kim, D.; Kim, K.; Kim, K.; Kim, M.; Kim, W.; Klein, A.; Klein, F.; Klimenko, A.; Klusman, M.; Kossov, M.; Kramer, L.; Kuang, Y.; Kuhn, S.; Kuhn, J.; Lachniet, J.; Laget, J.; Lawrence, D.; Li, Ji; Lukashin, K.; Manak, J.; Marchand, C.; Maximon, L.; McAleer, S.; McCarthy, J.; McNabb, J.; Mecking, B.; Mehrabyan, S.; Melone, J.; Mestayer, M.; Meyer, C.; Mikhailov, K.; Minehart, R.; Mirazita, M.; Miskimen, R.; Morand, L.; Morrow, S.; Mozer, M.; Muccifora, V.; Mueller, J.; Murphy, L.; Mutchler, G.; Napolitano, J.; Nasseripour, R.; Nelson, S.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niczyporuk, B.; Niyazov, R.; Nozar, M.; O'Rielly, G.; Opper, A.; Osipenko, M.; Park, K.; Pasyuk, E.; Peterson, G.; Philips, S.; Pivnyuk, N.; Pocanic, D.; Pogorelko, O.; Polli, E.; Pozdniakov, S.; Preedom, B.; Price, J.; Prok, Y.; Protopopescu, D.; Qin, L.; Raue, B.; Riccardi, G.; Ricco, G.; Ripani, M.; Ritchie, B.; Ronchetti, F.; Rossi, P.; Rowntree, D.; Rubin, P.; Sabatié, F.; Sabourov, K.; Salgado, C.; Santoro, J.; Sapunenko, V.; Schumacher, R.; Serov, V.; Sharabian, Y.; Shaw, J.; Simionatto, S.; Skabelin, A.; Smith, E.; Smith, L.; Sober, D.; Spraker, M.; Stavinsky, A.; Stoler, P.; Strakovsky, I.; Strauch, S.; Strikman, M.; Taiuti, M.; Taylor, S.; Tedeschi, D.; Thoma, U.; Thompson, R.; Todor, L.; Tur, C.; Ungaro, M.; Vineyard, M.; Vlassov, A.; Wang, K.; Weisberg, A.; Weller, H.; Weygand, D.; Whisnant, C.; Wolin, E.; Wood, M.; Yegneswaran, A.; Yun, J.; Zhang, B.; Zhao, J.; Zhou, Z.

    2003-07-01

    The ratios of inclusive electron scattering cross sections of 4He, 12C, and 56Fe to 3He have been measured for the first time. It is shown that these ratios are independent of xB at Q2>1.4 GeV2 for xB>1.5, where the inclusive cross section depends primarily on the high momentum components of the nuclear wave function. The observed scaling shows that the momentum distributions at high-momenta have the same shape for all nuclei and differ only by a scale factor. The observed onset of the scaling at Q2>1.4 GeV2 and xB>1.5 is consistent with the kinematical expectation that two-nucleon short range correlations (SRC) dominate the nuclear wave function at pm≳300 MeV/c. The values of these ratios in the scaling region can be related to the relative probabilities of SRC in nuclei with A⩾3. Our data, combined with calculations and other measurements of the 3He/deuterium ratio, demonstrate that for nuclei with A⩾12 these probabilities are 4.9 5.9 times larger than in deuterium, while for 4He it is larger by a factor of about 3.8.

  3. Mathematical textbook of deformable neuroanatomies.

    PubMed

    Miller, M I; Christensen, G E; Amit, Y; Grenander, U

    1993-12-15

    Mathematical techniques are presented for the transformation of digital anatomical textbooks from the ideal to the individual, allowing for the representation of the variabilities manifest in normal human anatomies. The ideal textbook is constructed on a fixed coordinate system to contain all of the information currently available about the physical properties of neuroanatomies. This information is obtained via sensor probes such as magnetic resonance, as well as computed axial and emission tomography, along with symbolic information such as white- and gray-matter tracts, nuclei, etc. Human variability associated with individuals is accommodated by defining probabilistic transformations on the textbook coordinate system, the transformations forming mathematical translation groups of high dimension. The ideal is applied to the individual patient by finding the transformation which is consistent with physical properties of deformable elastic solids and which brings the coordinate system of the textbook to that of the patient. Registration, segmentation, and fusion all result automatically because the textbook carries symbolic values as well as multisensor features.

  4. Mathematical textbook of deformable neuroanatomies.

    PubMed Central

    Miller, M I; Christensen, G E; Amit, Y; Grenander, U

    1993-01-01

    Mathematical techniques are presented for the transformation of digital anatomical textbooks from the ideal to the individual, allowing for the representation of the variabilities manifest in normal human anatomies. The ideal textbook is constructed on a fixed coordinate system to contain all of the information currently available about the physical properties of neuroanatomies. This information is obtained via sensor probes such as magnetic resonance, as well as computed axial and emission tomography, along with symbolic information such as white- and gray-matter tracts, nuclei, etc. Human variability associated with individuals is accommodated by defining probabilistic transformations on the textbook coordinate system, the transformations forming mathematical translation groups of high dimension. The ideal is applied to the individual patient by finding the transformation which is consistent with physical properties of deformable elastic solids and which brings the coordinate system of the textbook to that of the patient. Registration, segmentation, and fusion all result automatically because the textbook carries symbolic values as well as multisensor features. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:8265653

  5. Towards the exact calculation of medium nuclei

    SciTech Connect

    Gandolfi, Stefano; Carlson, Joseph Allen; Lonardoni, Diego; Wang, Xiaobao

    2016-12-19

    The prediction of the structure of light and medium nuclei is crucial to test our knowledge of nuclear interactions. The calculation of the nuclei from two- and three-nucleon interactions obtained from rst principle is, however, one of the most challenging problems for many-body nuclear physics.

  6. Ice nuclei emissions from biomass burning

    Treesearch

    Markus D. Petters; Matthew T. Parsons; Anthony J. Prenni; Paul J. DeMott; Sonia M. Kreidenweis; Christian M. Carrico; Amy P. Sullivan; Gavin R. McMeeking; Ezra Levin; Cyle E. Wold; Jeffrey L. Collett; Hans Moosmuller

    2009-01-01

    Biomass burning is a significant source of carbonaceous aerosol in many regions of the world. When present, biomass burning particles may affect the microphysical properties of clouds through their ability to function as cloud condensation nuclei or ice nuclei. We report on measurements of the ice nucleation ability of biomass burning particles performed on laboratory-...

  7. Thalamic nuclei after human blunt head injury.

    PubMed

    Maxwell, William L; MacKinnon, Mary Anne; Smith, Douglas H; McIntosh, Tracy K; Graham, David I

    2006-05-01

    Paraffin-embedded blocks from the thalamus of 9 control patients, 9 moderately disabled, 12 severely disabled, and 10 vegetative head-injured patients assessed using the Glasgow Outcome Scale and identified from the Department of Neuropathology archive. Neurons, astrocytes, macrophages, and activated microglia were differentiated by Luxol fast blue/cresyl violet, GFAP, CD68, and CR3/43 staining and stereological techniques used to estimate cell number in a 28-microm-thick coronal section. Counts were made in subnuclei of the mediodorsal, lateral posterior, and ventral posterior nuclei, the intralaminar nuclei, and the related internal lamina. Neuronal loss occurred from mediodorsal parvocellularis, rostral center medial, central lateral and paracentral nuclei in moderately disabled patients; and from mediodorsal magnocellularis, caudal center medial, rhomboid, and parafascicular nuclei in severely disabled patients; and all of the above and the centre median nucleus in vegetative patients. Neuronal loss occurred primarily from cognitive and executive function nuclei, a lesser loss from somatosensory nuclei and the least loss from limbic motor nuclei. There was an increase in the number of reactive astrocytes, activated microglia, and macrophages with increasing severity of injury. The study provides novel quantitative evidence for differential neuronal loss, with survival after human head injury, from thalamic nuclei associated with different aspects of cortical activation.

  8. Modified particle-rotor model and low-lying rotational bands in odd-A triaxial nuclei

    NASA Astrophysics Data System (ADS)

    Modi, Swati; Patial, M.; Arumugam, P.; Maglione, E.; Ferreira, L. S.

    2017-09-01

    The low-lying rotational bands of triaxially deformed nuclei 137Pr, 137Pm and 139Eu are studied with a modified particle-rotor model following the nonadiabatic quasiparticle approach. The matrix elements of the odd-A nucleus are obtained in terms of a coupling matrix and the rotational energies of the even-even core. The spectra of the cores 136Ce, 136Nd and 138Sm indicate a strong influence of triaxial deformation and vibrational degrees of freedom. These properties are appropriately carried forward to the calculations for the odd-A nucleus. We demonstrate that the ground and side bands of the odd-A nucleus and its core can be explained with the same set of deformation parameters ({β }2, γ). We argue that this method could be useful in studying the low-lying states in exotic nuclei also.

  9. Studies Of Proton Emitting Nuclei At Legnaro National Laboratories

    NASA Astrophysics Data System (ADS)

    Soramel, F.; Guglielmetti, A.; Bonetti, R.; Gernetti, M.; Stroe, L.; Mazzocco, M.; Signorini, C.; Ivasçu, M.; Petrache, C. M.

    2003-09-01

    Since few years at the Legnaro National Laboratories we have recently started a program to study exotic decays at the proton drip-line with particular attention to proton radioactivity in the rare earth region. In fact pemitting nuclei with 54 < Z < 64 are expected to be quite deformed in their ground state and their study is an important input for the theoretical models that describe this kind of decay. Our studies have brought, as first result, the discovery of the decay by pemission of 117La where to p-decaying levels have been found. Our experimental program continued with the study of the decay of 126Pm. For this nucleus we can only conclude that our low statistics data show no evidence of p emission.

  10. Resurgent deformation quantisation

    SciTech Connect

    Garay, Mauricio; Goursac, Axel de; Straten, Duco van

    2014-03-15

    We construct a version of the complex Heisenberg algebra based on the idea of endless analytic continuation. The algebra would be large enough to capture quantum effects that escape ordinary formal deformation quantisation. -- Highlights: •We construct resurgent deformation quantisation. •We give integral formulæ. •We compute examples which show that hypergeometric functions appear naturally in quantum computations.

  11. Nuclei migrate through constricted spaces using microtubule motors and actin networks in C. elegans hypodermal cells.

    PubMed

    Bone, Courtney R; Chang, Yu-Tai; Cain, Natalie E; Murphy, Shaun P; Starr, Daniel A

    2016-11-15

    Cellular migrations through constricted spaces are a crucial aspect of many developmental and disease processes including hematopoiesis, inflammation and metastasis. A limiting factor in these events is nuclear deformation. Here, we establish an in vivo model in which nuclei can be visualized while moving through constrictions and use it to elucidate mechanisms for nuclear migration. C. elegans hypodermal P-cell larval nuclei traverse a narrow space that is about 5% their width. This constriction is blocked by fibrous organelles, structures that pass through P cells to connect the muscles to cuticle. Fibrous organelles are removed just prior to nuclear migration, when nuclei and lamins undergo extreme morphological changes to squeeze through the space. Both actin and microtubule networks are organized to mediate nuclear migration. The LINC complex, consisting of the SUN protein UNC-84 and the KASH protein UNC-83, recruits dynein and kinesin-1 to the nuclear surface. Both motors function in P-cell nuclear migration, but dynein, functioning through UNC-83, plays a more central role as nuclei migrate towards minus ends of polarized microtubule networks. Thus, the nucleoskeleton and cytoskeleton are coordinated to move nuclei through constricted spaces.

  12. Hidden pseudospin and spin symmetries and their origins in atomic nuclei

    NASA Astrophysics Data System (ADS)

    Liang, Haozhao; Meng, Jie; Zhou, Shan-Gui

    2015-03-01

    Symmetry plays a fundamental role in physics. The quasi-degeneracy between single-particle orbitals (n , l , j = l + 1 / 2) and (n - 1 , l + 2 , j = l + 3 / 2) indicates a hidden symmetry in atomic nuclei, the so-called pseudospin symmetry (PSS). Since the introduction of the concept of PSS in atomic nuclei, there have been comprehensive efforts to understand its origin. Both splittings of spin doublets and pseudospin doublets play critical roles in the evolution of magic numbers in exotic nuclei discovered by modern spectroscopic studies with radioactive ion beam facilities. Since the PSS was recognized as a relativistic symmetry in 1990s, many special features, including the spin symmetry (SS) for anti-nucleon, and many new concepts have been introduced. In the present Review, we focus on the recent progress on the PSS and SS in various systems and potentials, including extensions of the PSS study from stable to exotic nuclei, from non-confining to confining potentials, from local to non-local potentials, from central to tensor potentials, from bound to resonant states, from nucleon to anti-nucleon spectra, from nucleon to hyperon spectra, and from spherical to deformed nuclei. Open issues in this field are also discussed in detail, including the perturbative nature, the supersymmetric representation with similarity renormalization group, and the puzzle of intruder states.

  13. 76 FR 63702 - In the Matter of the Designation of Conspiracy of Fire Nuclei, aka Conspiracy of the Nuclei of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-13

    ... Conspiracy of Fire Nuclei, aka Conspiracy of the Nuclei of Fire, aka Conspiracy of Cells of Fire, aka Synomosia of Pyrinon Tis Fotias, aka Thessaloniki-Athens Fire Nuclei Conspiracy, as a Specially Designated... that the organization known as Conspiracy of Fire Nuclei, also known as Conspiracy of the Nuclei...

  14. Deformation mechanisms in experimentally deformed Boom Clay

    NASA Astrophysics Data System (ADS)

    Desbois, Guillaume; Schuck, Bernhard; Urai, Janos

    2016-04-01

    Bulk mechanical and transport properties of reference claystones for deep disposal of radioactive waste have been investigated since many years but little is known about microscale deformation mechanisms because accessing the relevant microstructure in these soft, very fine-grained, low permeable and low porous materials remains difficult. Recent development of ion beam polishing methods to prepare high quality damage free surfaces for scanning electron microscope (SEM) is opening new fields of microstructural investigation in claystones towards a better understanding of the deformation behavior transitional between rocks and soils. We present results of Boom Clay deformed in a triaxial cell in a consolidated - undrained test at a confining pressure of 0.375 MPa (i.e. close to natural value), with σ1 perpendicular to the bedding. Experiments stopped at 20 % strain. As a first approximation, the plasticity of the sample can be described by a Mohr-Coulomb type failure envelope with a coefficient of cohesion C = 0.117 MPa and an internal friction angle ϕ = 18.7°. After deformation test, the bulk sample shows a shear zone at an angle of about 35° from the vertical with an offset of about 5 mm. We used the "Lamipeel" method that allows producing a permanent absolutely plane and large size etched micro relief-replica in order to localize and to document the shear zone at the scale of the deformed core. High-resolution imaging of microstructures was mostly done by using the BIB-SEM method on key-regions identified after the "Lamipeel" method. Detailed BIB-SEM investigations of shear zones show the following: the boundaries between the shear zone and the host rock are sharp, clay aggregates and clastic grains are strongly reoriented parallel to the shear direction, and the porosity is significantly reduced in the shear zone and the grain size is smaller in the shear zone than in the host rock but there is no evidence for broken grains. Comparison of microstructures

  15. Deformation effects on cluster decays of radium isotopes

    NASA Astrophysics Data System (ADS)

    Soylu, A.; Evlice, S.

    2015-04-01

    We systematically investigate the influence of nuclear deformations of the cluster and daughter nuclei on the half-lives of 4He, 8,10Be, 12,14,16C and 16,18,20,22O cluster decays from 210-226Ra. The Wentzel-Kramers-Brillouin (WKB) method and Bohr-Sommerfeld quantization condition with the deformed squared Woods-Saxon and Cosh potentials are used phenomenologically in order to compute the half-lives. The calculations are performed for the spherical cluster and deformed daughter, deformed cluster and spherical daughter and deformed cluster and daughter cases. The half-lives for different orientation angles as well as over all angles are calculated, in order to show the deformation effects on the systems. In cases where the deformation of both cluster and daughter effect the result, it is found that the deformation of the cluster is more important than the deformation of the daughter. Furthermore, it is also found that taking into account the orientation angles of the daughter and cluster also improves the results when compared to experiment. However, the results for a Cosh potential with certain parameters without any deformation are found to be more compatible with both the results obtained by the Coulomb and proximity potential model (CPPM) and the universal formula for cluster decay (UNIV), as well as the experimental values for 4He and 14C decays. The results provide a useful method for estimating the unknown experimental half-lives of possible exotic decays from Ra isotopes.

  16. Leisure activities, apolipoprotein E e4 status, and the risk of dementia.

    PubMed

    Yang, Sheng-Ying; Weng, Pei-Hsuan; Chen, Jen-Hau; Chiou, Jeng-Min; Lew-Ting, Chih-Yin; Chen, Ta-Fu; Sun, Yu; Wen, Li-Li; Yip, Ping-Keung; Chu, Yi-Min; Chen, Yen-Ching

    2015-12-01

    Leisure activities have been associated with a decreased risk of dementia. However, to date, no study has explored how apolipoprotein E (ApoE) e4 status or vascular risk factors modified the association between leisure activities and dementia risks. This case-control study recruited patients (age ≥ 60 years) with Alzheimer's disease (AD; n = 292) and vascular dementia (VaD; n = 144) and healthy controls (n = 506) from three teaching hospitals in Taiwan between 2007 and 2010. Information on patient's leisure activities were obtained through a questionnaire. Conditional logistic regression models were used to assess the association of leisure activities and ApoE e4 status with the risk of dementia. High-frequency physical activity was associated with a decreased risk of AD [adjusted odds ratio (AOR) = 0.45], and the results become more evident among ApoE e4 carriers with AD (AOR = 0.30) and VaD (AOR = 0.26). Similar findings were observed for cognitive (AOR = 0.42) and social activities (AOR = 0.55) for AD. High-frequency physical, cognitive, and social activities were associated with a decreased risk of VaD (AOR = 0.29-0.60). Physical and social activities significantly interacted with each other on the risk of VaD (pinteraction = 0.04). Physical activity consistently protects against AD and VaD. Significant interactions were identified across different types of leisure activities in lowering dementia risk. Copyright © 2014. Published by Elsevier B.V.

  17. Study of the Exclusive d(e,e^'p)n Reaction Mechanism at High Q^2

    NASA Astrophysics Data System (ADS)

    Dashyan, Natalia; Egiyan, Kim

    2006-04-01

    High Q^2 d(e,e^'p)n scattering is one of the simplest and best ways to investigate the short range properties of the deuterium wave function (WF), possible modifications of the bound nucleon structure, as well as of the structure and nature of short range nucleon correlations (SRC). For these investigation, the mechanisms of this reaction should be understood properly. Although the d(e,e^'p)n reaction is the simplest one, its mechanism remains to be checked at high Q^2: short distances are involved and, therefore, it is unclear what degrees of freedom (nucleonic or quark-gluonic) play a more important role in electron-nucleon interaction. There are also subtle interplays between the interaction of different intermediate exited states of the struck fast nucleon with the second nucleon. To solve these problems the reaction should be investigated as completely as possible, at different kinematic conditions. We investigated the d(e,e^'p)n reaction mechanism in the Q^2 = (2 - 6) GeV^2 interval using the CLAS detector at Jefferson Lab. The angular and momentum distributions of recoil neutrons were studied in detail at momenta of pn = (0 - 2) GeV/c and in angular (relative to the transfered momentum direction) range 20^o - 160^o. The experimental data are compared with the theoretical calculations [1] based on the diagrammatic approach of , and reasonable agreement was obtained at least in the momentum range pn<= 1 GeV/c. [1]J.-M. Laget, Phys. Lett. B609, 49 (2005).

  18. Study on fractal characteristics in the e+e- collisions at s = 250GeV

    NASA Astrophysics Data System (ADS)

    Zeng, Ting-Ting; Chen, Gang; Dong, Zi-Jian; She, Zhi-Lei; Ragab, N. A.

    2017-08-01

    The fractal characteristics of multiparticle final state are first studied in the e+e- collision of s = 250GeV, with the MC simulation generator Jetset7.4 and Herwig5.9. The results show that this multiparticle final state has a double-Hurst-exponent fractals characteristics, which means that the resulting NFM obeys the scaling law well using both the two sets of Hurst exponents to partition the three-dimensional phase space isotropically and anisotropically. Their fractal indices and the effective fluctuation strength are also predicted.

  19. Overview of the CMD-3 recent results at e+e- collider VEPP-2000

    NASA Astrophysics Data System (ADS)

    Fedotovich, G. V.; Akhmetshin, R. R.; Anisenkov, A. V.; Aulchenko, V. M.; Banzarov, V. S.; Bashtovoy, N. S.; Berkaev, D. E.; Bragin, A. V.; Eidelman, S. I.; Epifanov, D. A.; Epshteyn, L. B.; Erofeev, A. L.; Gayazov, S. E.; Grebenuk, A. A.; Grigoriev, D. N.; Gromov, E. M.; Ignatov, F. V.; Ivanov, V. L.; Karpov, S. V.; Kazanin, V. F.; Khazin, B. I.; Kirpotin, A. N.; Koop, I. A.; Kovalenko, O. A.; Kozyrev, A. N.; Kozyrev, E. A.; Krokovny, P. P.; Kuzmenko, A. E.; Kuzmin, A. S.; Logashenko, I. B.; Lukin, P. A.; Lysenko, A. P.; Mikhailov, K. Yu.; Okhapkin, V. S.; Pestov, Yu. N.; Perevedentsev, E. A.; Popov, A. S.; Razuvaev, G. P.; Rogovsky, Yu. A.; Romanov, A. L.; Ruban, A. A.; Ryskulov, N. M.; Ryzhenenkov, A. E.; Shebalin, V. E.; Shemyakin, D. N.; Shwartz, B. A.; Shwartz, D. B.; Sibidanov, A. L.; Shatunov, P. Yu.; Shatunov, Yu. M.; Solodov, E. P.; Titov, V. M.; Talyshev, A. A.; Vorobiov, A. I.; Yudin, Yu. V.; Zharinov, Yu. M.

    2016-11-01

    Since December 2010, the CMD-3 detector has collected data at the electronpositron collider VEPP-2000. The sample of the accumulated data corresponds to about 60 pb-1 of integrated luminosity in the c.m. energy from 0.32 up to 2 GeV. Preliminary results of the analysis of various processes e+e- annihilation to hadrons are presented. It is shown the processes with multihadron events have several intermediate states which must be taken into account to correctly describe the angular and invariant mass distributions as well as cross section dependence versus energy.

  20. Study of the e+e- to hadrons via ISR at BABAR

    NASA Astrophysics Data System (ADS)

    Solodov, E. P.

    2010-06-01

    Experimental data from the PEP-II B-factory at 10.6 GeV center-of-mass (c.m.) energy, obtained via initial-state radiation (ISR) with the BABAR detector, are presented. The cross sections for many hadronic processes have been measured from the production threshold to 4-5 GeV of the e+e- c.m. energy. The obtained data allow to study a number of intermediate states and determine the parameters of known resonances and their branching fractions. The exclusive cross section for some number of hadronic sub-processes are presented.