WorldWideScience

Sample records for giant monopole resonance

  1. Monopole Giant Resonances and TDHF boundary conditions

    International Nuclear Information System (INIS)

    Stevenson, P.D.; Almehed, D.; Reinhard, P.-G.; Maruhn, J.A.

    2007-01-01

    Using time-dependent Hartree-Fock, we induce isoscalar and isovector monopole vibrations and follow the subsequent vibrations of both the same and opposite isospin nature in the N Z nucleus 132 Sn. By suitable scaling of the proton and neutron parts of the excitation operators, the coupling between the modes is studied, and the approximate normal modes found. Chaotic dynamics are then analysed in the isoscalar giant monopole resonance by using reflecting boundaries in a large space to build up a large number of 0 + states whose spacings are then analysed. A Wigner-like distribution is found

  2. The sympletic model for giant monopole resonances

    International Nuclear Information System (INIS)

    Oliveira, M.M.B.M.

    1985-01-01

    Following recently published articles, it's investigated how to apply the sympletic model to the study of giant monopole resonances in spherical nuclei. The results obtained agree with those already published for monopole mode energies, wave functions, radii and nuclear incompressibility of 16 O and 40 Ca nuclei. An analyse of how the spurious center-of-mass motion influence resonance energies is made. The sum rules of the monopole operator, m-bar e , o ≤ e ≤ 3, are calculated, demonstrating at first that they are conserved in the sympletic model. Then it's studied, for those sum rules, the importance of n-boson correlations in the fundamental state, which is an extension of those sum rules, of the analysis for the nuclear incompressibility, performed in above mentioned articles. (Author) [pt

  3. Evidence for deformation effect on the giant monopole resonance

    International Nuclear Information System (INIS)

    Buenerd, M.; Lebrun, D.; Martin, P.; de Saintignon, P.; Perrin, C.

    1980-01-01

    The giant monopole resonance in the region of deformed nuclei has been investigated by inelastic scattering of 108.5 MeV 3 He at very small scattering angles. Evidence is reported for coupling between the giant monopole and giant quadrupole vibrations, based both on energy shift and transition strength

  4. Excitation of giant monopole and quadrupole resonances

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, H. [Osaka Univ., Suita (Japan). Research Center for Nuclear Physics; Yamagata, T.; Tanaka, M. [and others; Ikegami, H.; Muraoka, M. [eds.; Osaka Univ., Suita (Japan). Research Center for Nuclear Physics

    1980-01-01

    Recent studies on the giant monopole resonance (GMR) and the giant quadrupole resonance (GQR) in /sup 144/Sm and /sup 208/Pb using the ..cap alpha..-scattering performed at RCNP are summarized. The observed angular range covered 1.6/sup 0/ -- 7/sup 0/ with a coupled system of a dipole and a triplet quadrupole magnet. The incident energy was changed from 84 to 119 MeV. The resonance shapes and energy-weighted sum-rule strengths of the GMR and the GQR were reliably deduced as a function of incident energy. The quadrupole strength of --20% was found in the GMR region. The observed excitation function of the GMR was compared with the DWBA calculation, in which the Satchler's Version I was used as a form factor representing the compressional motion of the nucleus. It was found that the experimental excitation function of the GMR shows steeper decrease as lowering the incident energy than the DWBA prediction whereas that of the GQR is successfully described by the DWBA. This suggests that examination of the model describing the GMR is necessary.

  5. Giant monopole resonance in transitional and deformed nuclei

    International Nuclear Information System (INIS)

    Garg, U.; Bogucki, P.; Bronson, J.D.; Lui, Y.; Youngblood, D.H.

    1984-01-01

    Small-angle inelastic α-scattering measurements have been made at E/sub α/ = 129 MeV on /sup 144,148/Sm and /sup 142,146,150/Nd to investigate the giant monopole resonance in transitional and deformed nuclei. The experimental data reveal a mixing of L = 0 and L = 2 modes in 148 Sm resulting in almost identical angular distributions for the two components of the giant resonance peaks in the angular range 2 0 --6 0 . A ''splitting'' of the giant monopole resonance is observed in 150 Nd; the extent of this splitting is smaller than that reported for 154 Sm. Comparison is made with the predictions of various theoretical models

  6. Isovector giant monopole resonances: A sum-rule approach

    International Nuclear Information System (INIS)

    Goeke, K.; Bonn Univ.; Castel, B.

    1980-01-01

    Several useful sum rules associated with isovector giant monopole resonances are calculated for doubly closed shell nuclei. The calculation is based on techniques known from constrained and adiabatic time-dependent Hartree-Fock theories and assume various Skyrme interactions. The results obtained form, together with the compiled literature, the basis for a quantitative description of the RPA strength distribution in terms of energy-weighted moments. These, together with strength distribution properties, are determined by a hierarchy of determinantal relations between moments. The isovector giant monopole resonance turns out to be a rather broad resonance centered at E = 46 Asup(-1/10) MeV with an extended width of more than 16 MeV. The consequences regarding isospin impurities in the nuclear ground state are discussed. (orig.)

  7. Statistical decay of giant monopole resonance in 208Pb

    International Nuclear Information System (INIS)

    Dias, H.; Wolynec, E.

    1984-01-01

    The neutron spectrum from the decay of the monopole giant resonance in 208 Pb is calculated using the known energy levels of 207 Pb. The particle vibrator model is used to assign spins parities to the measured 207 Pb levels, where these were not avaliable from experiments. The results of the Hauser-Feshbach calculation is in excellent agreement with the experimental spectrum, showing that the observed fast neutrons can be completely explained assuming a statistical decay. (Author) [pt

  8. Decay of the giant monopole resonance in heavy nuclei

    International Nuclear Information System (INIS)

    Brandenburg, S.

    1985-01-01

    In this thesis an experimental study of the properties of the giant monopole resonance (GMR) in nuclei is described. The main subject is the study of the neutron decay of the GMR in 208 Pb, and the fission decay of the GMR in 238 U. Furthermore the strength distribution and decay properties of the monopole strength in 24 Mg and 40 Ca were studied. The strength distribution of the isoscalar monopole (and also of the isoscalar dipole) strength as obtained from the angular distribution of the excited strength at small scattering angles are discussed. For the excitation of the GMR inelastic scattering at very small scattering angles, including 0 0 , of 120 MeV α-particles was employed. The experimental technique for performing this type of measurements at the KVI was developed in the course of this study and is the subject of a separate chapter. (Auth.)

  9. Strength function for the giant isovector monopole resonance

    International Nuclear Information System (INIS)

    MacDonald, W.M.; Birse, M.C.

    1984-01-01

    The theory of the strength function for giant resonances is extended to exhibit the explicit energy dependence of the width and shift functions for the giant isovector monopole. An integral sum rule on the width GAMMA/sub M/(E) relates its normalization to the second moment M 2 of the strength function and leads to a relation GAMMA/sub M/(E/sub M/)GAMMA/sub s//4 = M 2 between M 2 and the width at the maximum, which involves the width GAMMA/sub s/ of the distribution in energy of the spreading matrix elements. An estimate of GAMMA/sub M/(E/sub M/)approx. =8 MeV based on the absorptive part of the optical potential together with random-phase approximation calculations of M 2 leads to the result GAMMA/sub s//2approx. =2hω, supporting the intermediate coupling model of Lane, Thomas, and Wigner. Using the sum rule expressions of Lane and Mekjian to evaluate the Coulomb matrix element M/sub A/M between an isobaric analog state and its corresponding isovector monopole, we test this strength function for the isovector monopole by calculating the spreading widths for the ground state analogs of nuclei from 38 Cl to 208 Pb. The good agreement with the systematic dependence upon mass number and isospin resolves the long-standing discrepancy between the estimate GAMMA/sub M/(E/sub M/)approx.8--10 MeV and the value GAMMA/sub M/(E/sub A/)< or =2 MeV needed to account for the spreading widths of the isobaric analog state

  10. Collisional damping of giant monopole and quadrupole resonances

    International Nuclear Information System (INIS)

    Yildirim, S.; Gokalp, A.; Yilmaz, O.; Ayik, S.

    2001-01-01

    Collisional damping widths of giant monopole and quadrupole excitations for 120 Sn and 208 Pb at zero and finite temperatures are calculated within Thomas-Fermi approximation by employing the microscopic in-medium cross-sections of Li and Machleidt and the phenomenological Skyrme and Gogny forces, and are compared with each other. The results for the collisional widths of giant monopole and quadrupole vibrations at zero temperature as a function of the mass number show that the collisional damping of giant monopole vibrations accounts for about 30 - 40% of the observed widths at zero temperature, while for giant quadrupole vibrations it accounts for only 20 - 30% of the observed widths at zero temperature. (orig.)

  11. Structure and direct decay of Giant Monopole Resonances

    International Nuclear Information System (INIS)

    Avez, B.; Simenel, C.

    2013-01-01

    We study structure and direct decay of the Giant Monopole Resonance (GMR) at the Random Phase Approximation (RPA) level using the time-dependent energy density functional method in the linear response regime in a few doubly magic nuclei. A proper treatment of the continuum, through the use of large coordinate space, allows for a separation between the nucleus and its emitted nucleons. The microscopic structure of the GMR is investigated with the decomposition of the strength function into individual single-particle quantum numbers. A similar microscopic decomposition of the spectra of emitted nucleons by direct decay of the GMR is performed. In this harmonic picture of giant resonance, shifting every contribution by the initial single-particle energy allows to reconstruct the GMR strength function. The RPA residual interaction couples bound 1-particle 1-hole states to unbound ones, allowing for the total decay of the GMR. In this article, we then intend to get an understanding of the direct decay mechanism from coherent one-particle-one-hole superpositions, while neglecting more complex configurations. Time-dependent beyond mean-field approaches should be used, in the future, to extend this method. (orig.)

  12. (p,n) and (n,p) reactions as probes of isovector giant monopole resonances

    International Nuclear Information System (INIS)

    Auerbach, N.; Bowman, J.D.; Franey, M.A.; Love, W.G.

    1983-01-01

    Nucleon charge exchange reactions are explored as prospective probes of isovector giant monopole resonances. Using charge exchange transition densities based on random-phase approximation sum rules, distorted wave impulse approximation calculations are made for the (p,n) and (n,p) reactions exciting the isovector giant monopole resonances in several nuclei at bombarding energies of 120 and 800 MeV. Based on our calculations, the charge exchange reactions at 800 MeV appear more promising

  13. Direct neutron decay from the giant monopole resonance in 208Pb

    International Nuclear Information System (INIS)

    Bracco, A.; Beene, J.R.; Van Giai, N.; Bortignon, P.F.; Zardi, F.; Broglia, R.A.

    1988-01-01

    Experimental values of partial direct escape widths for the giant monopole resonance (GMR) in 208 Pb are presented and compared with predictions from various RPA models. It is found that different model Hamiltonians that reproduce equally well the energy and strength of the GMR in 208 Pb lead to direct escape width which may differ by a large factor. 1 tab

  14. Deformation-induced splitting of the monopole giant resonance in 24Mg

    Directory of Open Access Journals (Sweden)

    Kvasil J.

    2016-01-01

    Full Text Available The strong deformation splitting of the isoscalar giant monopole resonance (ISGMR, recently observed in (α, α′ reaction in prolate 24Mg, is analyzed in the framework of the Skyrme quasiparticle randomphase-approximation (QRPA approach with the Skyrme forces SkM*, SVbas and SkPδ. The calculations with these forces give close results and confirm that the low-energy E0-peak is caused by the deformation-induced coupling of ISGMR with the K = 0 branch of the isoscalar giant quadrupole resonance.

  15. Comment on '(p,n) and (n,p) reactions as probes of isovector giant monopole resonances'

    International Nuclear Information System (INIS)

    Bauhoff, W.

    1984-01-01

    The importance of medium corrections in the excitation of the isovector giant monopole resonance by nucleons is investigated. A large reduction of the cross-section, compared to calculations with free t-matrices, is found at projectile energies around 100 MeV. This will make observation of the isovector monopole at these energies even more difficult than estimated by Auerbach et al

  16. Decay of the isoscalar giant monopole resonance in 208Pb and 238U

    International Nuclear Information System (INIS)

    Woude, A. van der

    1985-01-01

    In this paper, the neutron decay of the giant monopole resonance (GMR) of 208 Pb and the alpha decay of the GMR of 238 U is studied. The GMR is excited by inelastic alpha-scattering at small angles (0-3deg) using 120 MeV alpha particles. The interference of other processes like the knock-out process with the particle decay of these resonances is considered. Coincidence neutron and alpha spectra are presented, as well as E2/E0 strength distributions. (Auth.)

  17. Time-dependent Hartree-Fock calculation of the escape width of the giant monopole resonance in 16O

    International Nuclear Information System (INIS)

    Pacheco, J.M.; Maglione, E.; Broglia, R.A.

    1988-01-01

    The damping of the giant monopole resonance in 16 O is calculated within the framework of the time-dependent Hartree-Fock approximation. The strength function contains two peaks, centered at around 25 and 33 MeV, with escape widths of ∼11 and ∼2 MeV, associated with the 1p(0p) -1 and 1s(0s) -1 configurations, respectively

  18. On the role of anti-bound states in the RPA description of the giant monopole resonance

    International Nuclear Information System (INIS)

    Vertse, T.; Bang, J.

    1989-01-01

    The limit of the applicability of the resonant Random Phase Approximation (RPA) method is tested by calculating escape widths in the giant monopole resonance of 16 O and comparing them to the results of a time dependent Hartree-Fock calculation. Though the widths of the narrow s-wave component agree reasonably well, the broad p-wave component shows large disagreement, which cannot be cured by complementing the basis with anti-bound states in the RPA calculation. (author) 18 refs.; 3 tabs

  19. Excitation of giant monopole resonance in {sup 208}Pb and {sup 116}Sn using inelastic deuteron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Patel, D.; Garg, U. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Itoh, M. [Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578 (Japan); Akimune, H. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Berg, G.P.A. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Fujiwara, M. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); Harakeh, M.N. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA Groningen (Netherlands); GANIL, CEA/DSM-CNRS/IN2P3, 14076 Caen (France); Iwamoto, C. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Kawabata, T. [Division of Physics and Astronomy, Kyoto University, Kyoto 606-8502 (Japan); Kawase, K. [Japan Atomic Energy Agency, Kyoto 619-0215 (Japan); Matta, J.T. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Murakami, T. [Division of Physics and Astronomy, Kyoto University, Kyoto 606-8502 (Japan); Okamoto, A. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Sako, T. [Japan Atomic Energy Agency, Kyoto 619-0215 (Japan); Schlax, K.W. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Takahashi, F. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); White, M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Yosoi, M. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan)

    2014-07-30

    The excitation of the isoscalar giant monopole resonance (ISGMR) in {sup 208}Pb and {sup 116}Sn has been investigated using small-angle (including 0°) inelastic scattering of 100 MeV/u deuteron and multipole-decomposition analysis (MDA). The extracted strength distributions agree well with those from inelastic scattering of 100 MeV/u α particles. These measurements establish deuteron inelastic scattering at E{sub d}∼100 MeV/u as a suitable probe for extraction of the ISGMR strength with MDA, making feasible the investigation of this resonance in radioactive isotopes in inverse kinematics.

  20. Isotopic effect giant resonances

    International Nuclear Information System (INIS)

    Buenerd, M.; Lebrun, D.; Martin, P.; Perrin, G.; Saintignon, P. de; Chauvin, J.; Duhamel, G.

    1981-10-01

    The systematics of the excitation energy of the giant dipole, monopole, and quadrupole resonances are shown to exhibit an isotopic effect. For a given element, the excitation energy of the transition decreases faster with the increasing neutron number than the empirical laws fitting the overall data. This effect is discussed in terms of the available models

  1. Isotopic Dependence of the Giant Monopole Resonance in the Even-A 112-124Sn Isotopes and the Asymmetry Term in Nuclear Incompressibility

    International Nuclear Information System (INIS)

    Li, T.; Garg, U.; Liu, Y.; Marks, R.; Nayak, B. K.; Rao, P. V. Madhusudhana; Fujiwara, M.; Hashimoto, H.; Kawase, K.; Nakanishi, K.; Okumura, S.; Yosoi, M.; Itoh, M.; Ichikawa, M.; Matsuo, R.; Terazono, T.; Uchida, M.; Kawabata, T.; Akimune, H.; Iwao, Y.

    2007-01-01

    The strength distributions of the giant monopole resonance (GMR) have been measured in the even-A Sn isotopes (A=112-124) with inelastic scattering of 400-MeV α particles in the angular range 0 deg. - 8.5 deg. We find that the experimentally observed GMR energies of the Sn isotopes are lower than the values predicted by theoretical calculations that reproduce the GMR energies in 208 Pb and 90 Zr very well. From the GMR data, a value of K τ =-550±100 MeV is obtained for the asymmetry term in the nuclear incompressibility

  2. Isotopic Dependence of the Giant Monopole Resonance in the Even-A Sn112 124 Isotopes and the Asymmetry Term in Nuclear Incompressibility

    Science.gov (United States)

    Li, T.; Garg, U.; Liu, Y.; Marks, R.; Nayak, B. K.; Rao, P. V. Madhusudhana; Fujiwara, M.; Hashimoto, H.; Kawase, K.; Nakanishi, K.; Okumura, S.; Yosoi, M.; Itoh, M.; Ichikawa, M.; Matsuo, R.; Terazono, T.; Uchida, M.; Kawabata, T.; Akimune, H.; Iwao, Y.; Murakami, T.; Sakaguchi, H.; Terashima, S.; Yasuda, Y.; Zenihiro, J.; Harakeh, M. N.

    2007-10-01

    The strength distributions of the giant monopole resonance (GMR) have been measured in the even-A Sn isotopes (A=112 124) with inelastic scattering of 400-MeV α particles in the angular range 0° 8.5°. We find that the experimentally observed GMR energies of the Sn isotopes are lower than the values predicted by theoretical calculations that reproduce the GMR energies in Pb208 and Zr90 very well. From the GMR data, a value of Kτ=-550±100MeV is obtained for the asymmetry term in the nuclear incompressibility.

  3. Testing the mutually enhanced magicity effect in nuclear incompressibility via the giant monopole resonance in the {sup 204,206,208}Pb isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Patel, D. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Garg, U., E-mail: garg@nd.edu [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Fujiwara, M. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); Adachi, T. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA Groningen (Netherlands); Akimune, H. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Berg, G.P.A. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Harakeh, M.N. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA Groningen (Netherlands); GANIL, CEA/DSM-CNRS/IN2P3, 14076 Cean (France); Itoh, M. [Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578 (Japan); Iwamoto, C. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Long, A.; Matta, J.T. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Murakami, T. [Division of Physics and Astronomy, Kyoto University, Kyoto 606-8502 (Japan); Okamoto, A. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Sault, K. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Talwar, R. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, IN 46556 (United States); Uchida, M. [Department of Physics, Tokyo Institute of Technology, Tokyo 152-8850 (Japan); and others

    2013-10-07

    Using inelastic α-scattering at extremely forward angles, including 0°, the strength distributions of the isoscalar giant monopole resonance (ISGMR) have been measured in the {sup 204,206,208}Pb isotopes in order to examine the proposed mutually enhanced magicity (MEM) effect on the nuclear incompressibility. The MEM effect had been suggested as a likely explanation of the “softness” of nuclear incompressibility observed in the ISGMR measurements in the Sn and Cd isotopes. Our experimental results rule out any manifestation of the MEM effect in nuclear incompressibility and leave the question of the softness of the open-shell nuclei unresolved still.

  4. Giant nuclear resonances

    International Nuclear Information System (INIS)

    Snover, K.A.

    1989-01-01

    Giant nuclear resonances are elementary mods of oscillation of the whole nucleus, closely related to the normal modes of oscillation of coupled mechanical systems. They occur systematically in most if not all nuclei, with oscillation energies typically in the range 10-30 MeV. One of the best - known examples is the giant electric dipole (El) resonance, in which all the protons and all the neutrons oscillate with opposite phase, producing a large time - varying electric dipole moment which acts as an effective antenna for radiating gamma ray. This paper discusses this mode as well as quadrupole and monopole modes

  5. Giant monopole resonance in even-A Cd isotopes, the asymmetry term in nuclear incompressibility, and the 'softness' of Sn and Cd nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Patel, D. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Garg, U., E-mail: garg@nd.edu [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Fujiwara, M. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); Akimune, H. [Department of Physics, Konan University, Kobe 568-8501 (Japan); Berg, G.P.A. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Harakeh, M.N. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA Groningen (Netherlands); Itoh, M. [Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578 (Japan); Kawabata, T. [Center for Nuclear Studies, University of Tokyo, Tokyo 113-0033 (Japan); Kawase, K. [Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047 (Japan); Nayak, B.K. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Ohta, T. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); Ouchi, H. [Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578 (Japan); Piekarewicz, J. [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Uchida, M. [Department of Physics, Tokyo Institute of Technology, Tokyo 152-8850 (Japan); Yoshida, H.P. [Cyclotron and Radioisotope Center, Tohoku University, Sendai 980-8578 (Japan); Yosoi, M. [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan)

    2012-12-05

    The isoscalar giant monopole resonance (ISGMR) in even-A Cd isotopes has been studied by inelastic {alpha}-scattering at 100 MeV/u and at extremely forward angles, including 0 Degree-Sign . The asymmetry term in the nuclear incompressibility extracted from the ISGMR in Cd isotopes is found to be K{sub {tau}}=-555{+-}75 MeV, confirming the value previously obtained from the Sn isotopes. ISGMR strength has been computed in relativistic RPA using NL3 and FSUGold effective interactions. Both models significantly overestimate the centroids of the ISGMR strength in the Cd isotopes. Combined with other recent theoretical effort, the question of the 'softness' of the open-shell nuclei in the tin region remains open still.

  6. Giant monopole transition densities within the local scale ATDHF approach

    International Nuclear Information System (INIS)

    Dimitrova, S.S.; Petkov, I.Zh.; Stoitsov, M.V.

    1986-01-01

    Transition densities for 12 C, 16 O, 28 Si, 32 S, 40 Ca, 48 Ca, 56 Ni, 90 Zr, 208 Pb even-even nuclei corresponding to nuclear glant monopole resonances obtained within a local-scale adiabatic time-dependent Hartree-Fook approach in terms of effective Skyrme-type forces SkM and S3. The approach, the particular form and all necessary coefficients of these transition densities are reported. They are of a simple analytical form and may be directly used for example in analyses of particle inelastic scattering on nuclei by distorted wave method and a such a way allowing a test of the theoretical interpretation of giant monopole resonances

  7. Statistical decay of giant resonances

    International Nuclear Information System (INIS)

    Dias, H.; Teruya, N.; Wolynec, E.

    1986-02-01

    Statistical calculations to predict the neutron spectrum resulting from the decay of Giant Resonances are discussed. The dependence of the results on the optical potential parametrization and on the level density of the residual nucleus is assessed. A Hauser-Feshbach calculation is performed for the decay of the monopole giant resonance in 208 Pb using the experimental levels of 207 Pb from a recent compilation. The calculated statistical decay is in excellent agreement with recent experimental data, showing that decay of this resonance is dominantly statistical, as predicted by continuum RPA calculations. (Author) [pt

  8. Giant multipole resonances: an experimental review

    International Nuclear Information System (INIS)

    Bertrand, F.E.

    1979-01-01

    During the past several years experimental evidence has been published for the existance of nondipole giant resonances. These giant multipole resonances, the so-called new giant resonances were first observed through inelastic hadron and electron scattering and such measurements have continued to provide most of the information in this field. A summary is provided of the experimental evidence for these new resonances. The discussion deals only with results from inelastic scattering and only with the electric multipoles. Emphasis is placed on the recent observations of the giant monopole resonance. Results from recent heavy-ion and pion inelastic scattering are discussed. 38 references

  9. Static electromagnetic properties of giant resonances

    International Nuclear Information System (INIS)

    Koo, W.K.

    1986-03-01

    Static electric monopole and quadrupole matrix elements, which are related to the mean square radius and quadrupole moment respectively, are derived for giant resonances of arbitrary multipolarity. The results furnish information on the size and shape of the nucleus in the excited giant states. (author)

  10. Isoscalar giant resonances

    Energy Technology Data Exchange (ETDEWEB)

    Youngblood, D. H. [Texas A and M Univ., College Station (USA). Cyclotron Inst.; Ikegami, H.; Muraoka, M. [eds.

    1980-01-01

    The current status of the knowledges of giant quadrupole resonance (GQR), low energy octupole resonance (LEOR), and giant monopole resonance (GMR), is described. In the lowest order of multipole resonance, both isoscalar and isovector modes can occur. The characteristics of the GQR in light nuclei are apparent in the experimental result for Mg-24. All of the isoscalar E2 strength are known in Mg-24. The Goldhaber-Teller model is preferred over the Steinwedel-Jensen model for the giant dipole resonance (GDR) transition density. A few interesting and puzzling features have been seen in Pb-208. There is some conflict between inelastic alpha and electron scatterings. About LEOR, the RPA calculation of Liu and Brown was compared to the data for 3/sup -/ strength in Ca-40, Zr-90 and Pb-208. The calculation was employed the residual interaction of the Skyrme type. The agreement in Zr-90 was excellent. The effect of quadrupole deformation on the LEOR in Sm isotopes was large. The inelastic alpha scattering data on Al-27, Ca-40, Ti-48, Ni-58, Zn-64 and 66, Zr-90, Sn-116, 118, 120 and 124, Sm-144, 148 and 154, and Pb-208 were utilized in order to identify the GMR, and the GMR parameters were obtained. The GMR exhausting a large fraction of the sum rule was apparent in the nuclei with mass larger than 90. The splitting of the GDR and the broadening of the GQR in permanently deformed nuclei were established. The splitting of GMR was seen in Sm-154. The studies with heavy ions are also described.

  11. Determination of giant resonance strengths

    International Nuclear Information System (INIS)

    Serr, F.E.

    1983-01-01

    Using theoretical strength functions to describe the different giant resonances expected at excitation energies of the order of (60-85)/Asup(1/3) MeV, we calculate the double differential cross sections d 2 sigma/dΩ dE associated with the reactions 208 Pb(α, α') and 90 Zr(α, α') (Esub(α) = 152 MeV). The angular distributions for the giant quadrupole and giant monopole resonances obtained from fits to these spectra, making simple, commonly used assumptions for the peak shapes and background, are compared to the original angular distributions. The differences between them are an indication of some of the uncertainties affecting the giant resonance strengths extracted from hadron inelastic scattering data. Fits to limited angular regions lead to errors of up to 50% in the value of the energy-weighted sum rule, depending on the angles examined. While it seems possible to extract the correct EWSR for the GMR by carrying out the analyses at 0 0 , no single privileged angle seems to exist in the case of the GQR. (orig.)

  12. Excitation of giant resonances through inelastic scattering

    International Nuclear Information System (INIS)

    Kailas, S.

    1981-01-01

    In the last few years, exciting developments have taken place in the study of giant resonances (GR). In addition to the already well known gjant dipole resonance (GDR), the presence of at least two more new GRs viz. giant quadrupole resonance (GQR) and giant monopole resonance (GMR) has been experimentally established. The systematics covering these GRs is found to be consistent with the theoretical expectation. Though the existence of higher multipoles has been predjcted by theory, so far only some of these have been found to be excited experimentally. Various probe particles - electrons, protons (polarized and unpolarized), light and heavy ions and pions - at different bombarding energies have been used to excite the GR region, primarily through the inelastic scattering process. Detailed experiments, looking at the decay modes of GR region, have also been performed. These studies have contributed significantly to a better understanding of the phenomenon of nuclear collective excitation. In this report, the current status of 'GR' research is reviewed. (author)

  13. A sum rule description of giant resonances at finite temperature

    International Nuclear Information System (INIS)

    Meyer, J.; Quentin, P.; Brack, M.

    1983-01-01

    A generalization of the sum rule approach to collective motion at finite temperature is presented. The m 1 and msub(-1) sum rules for the isovector dipole and the isoscalar monopole electric modes have been evaluated with the modified SkM force for the 208 Pb nucleus. The variation of the resulting giant resonance energies with temperature is discussed. (orig.)

  14. Isoscalar giant resonances in a relativistic model

    International Nuclear Information System (INIS)

    L'Huillier, M.; Nguyen Van Giai.

    1988-07-01

    Isoscalar giant resonances in finite nuclei are studied in a relativistic Random Phase Approximation (RRPA) approach. The model is self-consistent in the sense that one set of coupling constants generates the Dirac-Hartree single-particle spectrum and the residual particle-hole interaction. The RRPA is used to calculate response functions of multipolarity L = 0,2,3, and 4 in light and medium nuclei. It is found that monopole and quadrupole modes exhibit a collective character. The peak energies are overestimated, but not as much as one might think if the bulk properties (compression modulus, effective mass) were the only relevant quantities

  15. Hybrid model for the decay of nuclear giant resonances

    International Nuclear Information System (INIS)

    Hussein, M.S.

    1986-12-01

    The decay properties of nuclear giant multipole resonances are discussed within a hybrid model that incorporates, in a unitary consistent way, both the coherent and statistical features. It is suggested that the 'direct' decay of the GR is described with continuum first RPA and the statistical decay calculated with a modified Hauser-Feshbach model. Application is made to the decay of the giant monopole resonance in 208 Pb. Suggestions are made concerning the calculation of the mixing parameter using the statistical properties of the shell model eigenstates at high excitation energies. (Author) [pt

  16. Hadron excitation of giant resonances

    International Nuclear Information System (INIS)

    Morsch, H.-P.

    1985-01-01

    A review is given on giant resonance studies in heavy nuclei using scattering of different hadronic probes. Concerning isoscalar giant resonances compression modes are discussed with the possibility to obtain more detailed structure information. From detailed studies of α scattering the distribution of isoscalar strengths of multipolarity up to L=6 was obtained. Some recent aspects of heavy ion excitation of collective modes are mentioned. The possibility to study isovector giant resonances in hadron charge exchange reactions is discussed. Finally, a comparison is made between α and 200 MeV proton scattering from which isoscalar and spin-isospin continuum response are extracted. (orig.)

  17. Recent Results From Skyrme-TDHF: Giant Resonances and Collisions

    International Nuclear Information System (INIS)

    Stevenson, Paul D.

    2007-01-01

    Using fully three-dimensional Time-Dependent Hartree-Fock with Skyrme forces allows one to explore small and large amplitude collective motion in nuclei using only an effective interaction fitted to ground state and nuclear matter properties as input. In this talk, results are presented for TDHF calculations of giant resonances and nuclear collisions. We examine deformation splitting of the giant dipole resonance on ground and excited intrinsic superdeformed states, showing the interplay between Landau splitting and deformation splitting, including effects of triaxiality[1]. In the case of giant monopole resonances, isospin-mixing is examined, showing that the isovector and isoscalar parts of strength functions are strongly coupled [2]. The role of absorption in the TDHF approach to linear and nonlinear regimes is examined[3]. Calculations of nuclear collisions are also explored, showing that the effects of fully relaxed symmetry produce new modes of energy loss not found in previous calculations [4]. (Author)

  18. The direct neutron decay of giant resonances in 208Pb

    International Nuclear Information System (INIS)

    Bracco, A.

    1988-01-01

    The neutron decay of the giant multipole resonance region from 9 to 15 MeV of excitation energy in 208 Pb has been studied. Neutron branching ratios for the decay to the ground state and to the low-lying excited states of 207 Pb were measured as a function of the excitation energy of 208 Pb and compared to Hauser-Feshbach calculations. While the neutron branching ratios from the energy region of the isoscalar giant quadrupole resonance are reproduced by the calculations, the ratios from the energy region of the isoscalar giant monopole resonance show a conspicuous excess with respect to the statistical model predictions. The neutron yield from this energy region was analysed in terms of a multistep model of the compound nucleus which includes collective doorway channels. The total direct escape width as well as the associated direct partial escape widths to the lowest five valence hole states of 207 Pb were determined. (orig.)

  19. Statistical decay of giant resonances

    International Nuclear Information System (INIS)

    Dias, H.; Teruya, N.; Wolynec, E.

    1986-01-01

    Statistical calculations to predict the neutron spectrum resulting from the decay of Giant Resonances are discussed. The dependence of the resutls on the optical potential parametrization and on the level density of the residual nucleus is assessed. A Hauser-Feshbach calculation is performed for the decay of the monople giant resonance in 208 Pb using the experimental levels of 207 Pb from a recent compilation. The calculated statistical decay is in excelent agreement with recent experimental data, showing that the decay of this resonance is dominantly statistical, as predicted by continuum RPA calculations. (Author) [pt

  20. Statistical contribution in the giant multipolar resonance decay in hevay nuclei

    International Nuclear Information System (INIS)

    Teruya, N.

    1986-01-01

    Statistical calculations are made for the decay in the electric monopole giant resonance in 208 Pb and electric dipole giant resonance in 209 Bi, using the Hauser-Feshbach formalism. Calculations are done using the experimental energy levels of the corresponding residual nuclei. The particle-vibrator model is used for those experimental levels without spin and parity determination. The influence of different parametrizations of the optical potential in the statistical calculation result is also studied. (L.C.) [pt

  1. Giant first-forbidden resonances

    International Nuclear Information System (INIS)

    Krmpotic, F.; Nakayama, K.; Sao Paulo Univ.; Pio Galeao, A.; Sao Paulo Univ.

    1983-01-01

    Recent experimental data on first-forbidden charge-exchange resonances are discussed in the framework of a schematic model. We also evaluate the screening of the weak coupling constants induced by both the giant resonances and the δ-isobar. It is shown that the last effect does not depend on the multipolarity of the one-particle moment. Due to the same reason, the fraction of the reaction strength pushed up into the δ-resonance region is always the same regardless of the quantum numbers carried by the excitation. Simple expressions are derived for the dependence of the excitation energies of the first-forbidden giant resonances on the mass number and isospin of the target. The model reproduces consistently both the Gamow-Teller and the first-forbidden resonances. (orig.)

  2. Giant resonances: reaction theory approach

    International Nuclear Information System (INIS)

    Toledo Piza, A.F.R. de; Foglia, G.A.

    1989-09-01

    The study of giant resonances through the use of reaction theory approach is presented and discussed. Measurements of cross-sections to the many available decay channels following excitation of giant multipole resonances (GMR) led one to view these phenomena as complicated dynamical syndromes so that theoretical requirements for their study must be extended beyond the traditional bounds of nuclear structure models. The spectra of decay products following GMR excitation in heavy nuclei are well described by statistical model (Hauser-Feshback, HF) predictions indicated that spreading of the collective modes plays a major role in shaping exclusive cross-sections. (A.C.A.S.) [pt

  3. Excitation of giant resonances in heavy ion collisions

    International Nuclear Information System (INIS)

    Kuehn, W.

    1991-01-01

    Introduction: What are Giant Resonances? General Features of Giant Resonances, Macroscopic Description and Classification, Basic Excitation Mechanisms, Decay Modes, Giant Resonances Built on Excited States, Relativistic Coulomb Excitation of Giant Resonances, Experimental Situation. (orig.)

  4. Giant multipole resonances: perspectives after ten years

    International Nuclear Information System (INIS)

    Bertrand, F.E.

    1980-01-01

    Nearly ten years ago evidence was published for the first of the so-called giant multipole resonances, the giant quadrupole resonance. During the ensuing years research in this field has spread to many nuclear physics laboratories throughout the world. The present status of electric giant multipole resonances is reviewed. 24 figures, 1 table

  5. Giant resonances on excited states

    International Nuclear Information System (INIS)

    Besold, W.; Reinhard, P.G.; Toepffer, C.

    1984-01-01

    We derive modified RPA equations for small vibrations about excited states. The temperature dependence of collective excitations is examined. The formalism is applied to the ground state and the first excited state of 90 Zr in order to confirm a hypothesis which states that not only the ground state but every excited state of a nucleus has a giant resonance built upon it. (orig.)

  6. Fission decay properties of nuclear giant multipole resonances

    International Nuclear Information System (INIS)

    Dias, H.; Arruda Neto, J.D.T.; Hussein, M.S.; Carlson, B.V.

    1986-05-01

    The statistical fission decay properties of the giant dipole, quadrupole and monopole resonances in 236 U are investigated with the aid of the Hauser-Feshbach model. It is found, contrary to several recent claims, that the GQR fission decay probability is as large as that of the GDR, at energies higher than the fission barrier. At energies close to the f.b., the GQR fission probability is found to be appreciably larger than that of the GDR. The GMR fission probability follows closely that of the GQR. (Author) [pt

  7. On Landau Vlasov simulations of giant resonances

    International Nuclear Information System (INIS)

    Pi, M.; Schuck, P.; Suraud, E.; Gregoire, C.; Remaud, B.; Sebille, F.

    1987-05-01

    We present VUU calculations of giant resonances obtained in energetic heavy ion collisions. Also is considered the case of the giant dipole in 40 Ca and the possibility of studying the effects of rotation on such collective modes

  8. Giant resonances in heavy-ion reactions

    International Nuclear Information System (INIS)

    Hussein, M.S.

    1982-11-01

    The several roles of multipole giant resonances in heavy-ion reactions are discussed. In particular, the modifications in the effective ion-ion potencial due to the virtual excitation of giant resonances at low energies, are considered and estimated for several systems. Real excitation of giant resonances in heavy-ion reactions at intermediate energies are then discussed and their importance in the approach phase of deeply inelastic processes in emphasized. Several demonstrative examples are given. (Author) [pt

  9. Giant dipole resonance in hot nuclei

    International Nuclear Information System (INIS)

    Mau, N.V.

    1993-01-01

    Giant resonances built on an excited state of the nucleus at a finite temperature T are studied. The following questions are investigated: how long such collective effects occur in a nucleus when T increases. How the properties of the giant resonances vary when the temperature increases. How the study of giant resonances in hot nuclei can give information on the structure of the nucleus in a highly excited state. The special case of the giant dipole resonance is studied. Some of the experimental results are reviewed and in their theoretical interpretation is discussed. (K.A.). 56 refs., 20 figs., 4 tabs

  10. Electromagnetic decay of giant resonances

    International Nuclear Information System (INIS)

    Beene, J.R.; Bertrand, F.E.; Halbert, M.L.; Auble, R.L.; Hensley, D.C.; Horen, D.J.; Robinson, R.L.; Sayer, R.O.; Sjoreen, T.P.

    1985-01-01

    Coincidence experiments were done to investigate the photon and neutron emission from the giant resonance regions of 208 Pb and 90 Zr using the ORNL Spin Spectrometer, a 72-segment NaI detector system. We have determined the total gamma-decay probability, the ground-state gamma branching ratio, and the branching ratios to a number of low-lying states as a function of excitation energy in 208 Pb to approx.15 MeV. Similar data were also obtained on 90 Zr. The total yield of ground-state E2 gamma radiation in 208 Pb and the comparative absence of such radiation in 90 Zr can only be understood if decay of compound (damped) states is considered. Other observations in 208 Pb include the absence of a significant branch from the giant quadrupole resonance (GQR) to the 3 - state at 2.6 MeV, a strong branch to a 3 - state at 4.97 MeV from the same region, and transitions to various 1 - states between 5 to 7 MeV from the E* approx. 14 MeV region (EO resonance)

  11. On the nature of some monopole resonances of p-shell nuclei

    International Nuclear Information System (INIS)

    Filippov, G.F.; Vasilevsky, V.S.; Nesterov, A.V.

    1982-01-01

    The resonance structure of states of a continuous spectrum of light nuclei is studied. Using 7 Li and 8 Be as an example it is shown that in these nuclei there exist a near-threshold resonance the share of which is about 50-70 % of isoscalar monopole sum rule. The experimental method of finding the near-threshold resonances is described

  12. Electron inelastic scattering by compound nuclei and giant multipole resonances

    International Nuclear Information System (INIS)

    Dzhavadov, A.V.; Mukhtarov, A.I.; Mirabutalybov, M.M.

    1980-01-01

    Multipole giant resonances in heavy nuclei have been investigated with the application of the Danos-Greiner dynamic collective theory to the Tassi model. The monopole giant resonance has been studied in 158 Gd, 166 Er, 184 W, 232 Th and 238 V nuclei at the incident electron energy E=200 MeV. Dependences of the form factor square of electron scattering by a 166 Er nucleus on the scattering angle obtained in the distorted-wave high-energy approximation (DWHEA) are presented. Giant dipole and quadrupole resonances in 60 Ni and 90 Zr nuclei have been studied. A comparison has been made of theoretical results obtained in the DWHEA for the dependence of the form factor square on the effective momentum transfer with the experimental data. The analysis of the obtained results led to the following conclusions. To draw a conclusion about the validity of one or another nuclear model and methods for calculating form factors, it is necessary to investigate, both theoretically and experimentally, electron scattering at great angles (THETA>=70 deg). To obtain a good agreement it is necessary to take account of the actual proton and neutron distributions in the ground state and their dynamic properties in an excited state [ru

  13. Electroexcitation of giant multipole resonances in 208Pb

    International Nuclear Information System (INIS)

    Sasao, M.; Torizuka, Y.

    1977-01-01

    Electroexcitation of the nuclear continuum for 208 Pb at excitation energies up to 100 MeV has been measured at momentum transfers in the range from 0.45 to 1.2 fm -1 . Unfolding of the radiation tail was performed using a tail function which takes into account the multiple-photon emission effect. The spectra at these momentum transfers deviate significantly from the prediction of the Fermi-gas model but are consistent with the sum of the multipole strengths of the random-phase approximation; the excess cross section on the low excitation energy side indicates the excitation of multipole resonances. A series of 208 Pb spectra at low momentum transfers was expanded into E1, E2 (E0), E3, and higher multipole components using the q dependence of the Tassie model for isoscalar modes and the Goldhaber-Teller or Steinwedel-Jensen model for isovector modes. The giant dipole resonance thus obtained is consistent with that from photoreactions. Isoscalar and isovector giant quadrupole resonances are seen, respectively, at 11 and 22.5 MeV and an octupole resonance at 16 MeV. A monopole resonance is suggested at 13.5 MeV. The reduced 2 > 2 , B (E1), B (E2), and B (E3) consume most of the corresponding energy weighted sum rule if the q dependences of the Tassie and Goldhaber-Teller models are assumed. The results with these models are consistent with the random-phase approximation

  14. Isoscalar giant resonances and Landau parameters with density-dependent effective interactions

    International Nuclear Information System (INIS)

    Kohno, Michio; Ando, Kazuhiko

    1979-01-01

    Discussion is given on the relations between the Landau parameters and the isoscalar giant (quadrupole- and monopole-) resonance energies by using general density-dependent interactions. In the limit of infinite nuclear matter, the isoscalar giant quadrupole energy is shown to depend not only on the effective mass but also on the Landau parameter F 2 . Collective energies of the isoscalar giant resonances are calculated for 16 O and 40 Ca with four different effective interactions, G-0, B1, SII and SV, by using the scaling- and constrained Hartree-Fock-methods. It is shown that the dependence of the collective energies on the effective interactions is essentially determined by the Landau parameters. The G-0 force is found to be most successful in reproducing the giant resonance energies. Validity of the RPA-moment theorems is examined for the case of local density-dependent interactions. (author)

  15. Electromagnetic decay of giant resonances

    International Nuclear Information System (INIS)

    Beene, J.R.; Bertrand, F.E.; Halbert, M.L.; Auble, R.L.; Hensley, D.C.; Horen, D.J.; Robinson, R.L.; Sayer, R.O.; Sjoreen, T.P.

    1985-01-01

    Coincidence experiments are carried out to investigate the photon and neutron emission from the giant resonance regions of 208 Pb and 90 Zr using the ORNL Spin Spectrometer, a 72-segment NaI detector system. The authors determined the total gamma-decay probability, the ground-state gamma branching ratio, and the branching ratios to a number of low-lying states as a function of excitation energy in 208 Pb to ∼15 MeV. Similar data were also obtained on 90 Zr. The total yield of ground-state E2 gamma radiation in 208 Pb and the comparative absence of such radiation in 90 Zr can only be understood if decay of compound (damped) states is considered. (Auth.)

  16. Multipole giant resonances in highly excited nuclei

    International Nuclear Information System (INIS)

    Xia Keding; Cai Yanhuang

    1989-01-01

    The isoscalar giant surface resonance and giant dipole resonance in highly excited nuclei are discussed. Excitation energies of the giant modes in 208 Pb are calculated in a simplified model, using the concept of energy wieghted sum rule (EWSR), and the extended Thomas-Fermi approximation at the finite temperature is employed to describe the finite temperature is employed to describe the finite temperature equilibrium state. It is shown that EWSR and the energy of the resonance depend only weakly on temperature in the system. This weak dependence is analysed

  17. Nuclear giant resonances in coordinate space. A semiclassical density functional approach

    International Nuclear Information System (INIS)

    Gleissl, P.; Brack, M.; Meyer, J.; Quentin, P.

    1987-01-01

    We discuss the semiclassical description of nuclear giant resonances (GR) using a realistic Skyrme force (SkM*) and complete ETF density functionals. We present monopole (0 + ) eigenmodes of isoscalar (I=0) and isovector (I=1) type, which are in good agreement with experiment, and the corresponding m 1 and m 3 sum rules. We also present the temperature dependence of some typical GR energies (0 + , I=0,1; 1 - , I=1; 2 + , I=0) in 208 Pb

  18. Particle-hole calculation of the isobaric analog and isovector monopole resonances

    International Nuclear Information System (INIS)

    Auerbach, N.; Nguyen Van Giai

    1977-06-01

    The correlated proton particle-neutron hole spectrum is calculated for N>Z nuclei using a Skyrme type interaction and the response function method. The basis of the calculation is a complete one particle-one hole space with the continuum included. As a result the distribution of the isovector monopole strength in the analog nucleus is obtained. This distribution has a narrow peak which corresponds to the isobaric analog resonance and at higher energies a broad peak which is the isovector monopole resonance. The coupling between these two states is inherent in the calculation

  19. Observation of monopole strength in the 12C(e,e'p0)11B reaction

    International Nuclear Information System (INIS)

    Calarco, J.R.; Arruda-Neto, J.; Griffioen, K.A.; Hanna, S.S.; Hoffmann, D.H.H.; Neyer, B.; Rand, R.E.; Wienhard, K.; Yearian, M.R.

    1984-01-01

    The location of the giant monopole resonance and, therefore, the compressibility is unknown in light nuclei. The forward-backward (e, e'p) angular correlation asymmetry from 12 C has been measured and found to be very sensitive to monopole strength in the giant dipole resonance region. Similar reactions will, thus, provide a sensitive tool in the search for monopole strength in light nuclei. (orig.)

  20. A microscopic study of giant resonances in nuclei near drip lines

    CERN Document Server

    Sagawa, H; Zhang, X Z

    1999-01-01

    We study giant resonances using the self-consistent Hartree-Fock calculation plus the random phase approximation with Skyrme interactions. Including simultaneously both the isoscalar and the isovector correlation the RPA response function is calculated in the coordinate space so as to take properly into account the continuum effect. Giant monopole states are discussed in relation with the nuclear compression modulus of the nuclear matter K sub n sub m. The core polarization charges are also discussed in comparison with recent empirical data in sup 1 sup 0 sup 0 Sn region.

  1. Isoscalar giant resonances for nuclei with mass between 56 and 60

    International Nuclear Information System (INIS)

    Lui, Y.-W.; Youngblood, D.H.; Clark, H.L.; Tokimoto, Y.; John, B.

    2006-01-01

    The giant resonance region from 10 MeV x 56 Fe, 58 Ni, and 60 Ni has been studied with inelastic scattering of 240 MeV α particles at small angles, including 0 deg. Most of the expected isoscalar E0 and E2 strength has been identified below E x =40 MeV. Between 56 and 72% of the isoscalar E1 strength has been located in these nuclei. The mass dependence of the giant monopole energy between A=40 and 90 is compared to relativistic and nonrelativistic calculations for interactions with compressibility of nuclear matter K NM ∼211-225 MeV

  2. The isoscalar giant dipole resonance and nuclear incompressibility

    International Nuclear Information System (INIS)

    Garg, U.

    2000-01-01

    Complete text of publication follows. The current status of the experimental work on the ISOSCALAR giant dipole resonance (ISGDR) will be reviewed. ISGDR is an exotic mode of collective nuclear vibration and can be described as a hydrodynamical density oscillation in which the volume of the nucleus remains constant and the state can be visualized in the form of a compression wave-analogous to a sound wave-oscillating back and forth through the nucleus. [1] Convincing evidence for the ISGDR has now been obtained in inelastic α-scattering measurements at 200 MeV (IUCF) [2], 240 MeV (Texas A and M) [3] and 400 MeV (RCNP, Osaka) [4]. In all nuclei studied so far, the ISGDR strength is observed to be spread over a rather wide excitation-energy range (up to ∼ 15 MeV). The excitation energy of the ISGDR is related to the nuclear incompressibility, K ∞ . The ISGDR results so far point to a value for K ∞ that is ∼ 30-40% lower than the obtained from the energies of the other compressional mode, the giant monopole resonance. Results from recent theoretical attempts to reconcile this difference will be presented. This work has been supported in part by the U.S. National Science Foundation. (author)

  3. Looking inside giant resonance fine structure

    International Nuclear Information System (INIS)

    Ponomarev, V.Yu.; Voronov, V.V.

    1993-01-01

    Microscopic calculations of the fine structure of giant resonances for spherical nuclei are presented. Excited states are treated by wave function which takes into account coupling of simple one-phonon configurations with more complex ones. Nuclear structure calculations are applied to the description of the γ-decay of resonances into the ground and low-lying excited states. 16 refs.; 4 figs

  4. Collective motion and giant resonances

    International Nuclear Information System (INIS)

    Wilhelmi, Z.; Kicinska-Habior, M.

    1984-01-01

    The report contains 15 papers devoted to problems of giant collective excitations of nuclei, heavy-ion induced reactions and their bearing on various aspects of nuclear structure. In some of them the numerical data are given. (A.S.)

  5. Isovector giant quadrupole resonance in 63Cu

    International Nuclear Information System (INIS)

    Wolynec, E.; Pastura, V.F.S.; Martins, M.N.

    1988-01-01

    The decay of the isovector E2 giant resonance in 63 Cu has been studied by measuring the (e,2n) cross section, in the incident electron energy range 22-45 MeV. The photodisintegration induced by bremsstrahlung was also measured. The electrodisintegration results have been analyzed using the distorted wave Born approximation E1 and E2 virtual photon spectra to obtain these multipole components in the corresponding (γ,2n) cross section. It is found that the isovector E2 giant resonance decays dominantly by two-neutron emission in 63 Cu. This decay channel exhausts 65 percent of the energy weighted E2 sum. (author0 [pt

  6. Macroscopic description of isoscalar giant multipole resonances

    International Nuclear Information System (INIS)

    Nix, J.R.; Sierk, A.J.

    1980-01-01

    On the basis of a simple macroscopic model, we calculate the isoscalar giant-resonance energy as a function of mass number and multipole degree. The restoring force is determined from the distortion of the Fermi surface, and the inertia is determined for the incompressible, irrotational flow of nucleons with unit effective mass. With no adjustable parameters, the resulting closed expression reproduces correctly the available experimental data, namely the magnitude and dependence upon mass number of the giant quadrupole energy and the magnitude of the giant octupole energy for 208 Pb. We also calculate the isoscalar giant-resonance width as a function of mass number and multipole degree for various macroscopic damping mechanisms, including two-body viscosity, one-body dissipation, and modified one-body dissipation. None of these damping mechanisms reproduces correctly all features of the available experimental data, namely the magnitude and dependence upon mass number of the giant quadrupole width and the magnitude of the giant octupole width for 208 Pb

  7. First measurement of isoscalar giant resonances in a stored-beam experiment

    Directory of Open Access Journals (Sweden)

    J.C. Zamora

    2016-12-01

    Full Text Available A new technique developed for measuring nuclear reactions at low momentum transfer with stored beams in inverse kinematics was successfully used to study isoscalar giant resonances. The experiment was carried out at the experimental heavy-ion storage ring (ESR at the GSI facility using a stored 58Ni beam at 100 MeV/u and an internal helium gas-jet target. In these measurements, inelastically scattered α-recoils at very forward center-of-mass angles (θcm≤1.5° were detected with a dedicated setup, including ultra-high vacuum compatible detectors. Experimental results indicate a dominant contribution of the isoscalar giant monopole resonance at this very forward angular range. It was found that the monopole contribution exhausts 79−11+12% of the energy-weighted sum rule (EWSR, which agrees with measurements performed in normal kinematics. This opens up the opportunity to investigate the giant resonances in a large domain of unstable and exotic nuclei in the near future. It is a fundamental milestone towards new nuclear reaction studies with stored ion beams.

  8. Study of giant resonances with pions

    International Nuclear Information System (INIS)

    Baer, H.W.

    1984-01-01

    Recent results on giant resonances obtained with pion-inelastic scattering and with single- and double-charge-exchange scattering are reviewed. The states discussed are isobaric analog states, double-isobaric analog states, and isovector L = 0, 1, and 2 collective states. 36 references

  9. Giant resonances in the deformed continuum

    International Nuclear Information System (INIS)

    Nakatsukasa, T.; Yabana, K.

    2004-01-01

    Giant resonances in the continuum for deformed nuclei are studied with the time-dependent Hartree-Fock (TDHF) theory in real time and real space. The continuum effect is effectively taken into account by introducing a complex Absorbing Boundary Condition (ABC). (orig.)

  10. Giant dipole resonances built on excited states

    International Nuclear Information System (INIS)

    Snover, K.A.

    1983-01-01

    The properties of giant dipole resonances built on excited nuclear states are reviewed, with emphasis on recent results. Nonstatistical (p,γ) reactions in light nuclei, and statistical complex-particle reactions in light and heavy nuclei are discussed. 27 references

  11. Giant dipole resonance by many levels theory

    International Nuclear Information System (INIS)

    Mondaini, R.P.

    1977-01-01

    The many levels theory is applied to photonuclear effect, in particular, in giant dipole resonance. A review about photonuclear dipole absorption, comparing with atomic case is done. The derivation of sum rules; their modifications by introduction of the concepts of effective charges and mass and the Siegert theorem. The experimental distributions are compared with results obtained by curve adjustment. (M.C.K.) [pt

  12. Stability of the giant dipole resonance

    International Nuclear Information System (INIS)

    Espino, J.M.; Gallardo, M.

    1987-01-01

    The Giant Dipole Resonance (GDR), because of its stability and its typical period of vibration, can be used as a test for compound nucleus reactions at high temperatures. This stability is studied in a simple model up to 6 MeV of temperature. The experimental methods for getting the properties of the GDR at T ≠ 0 are also commented. (author)

  13. Electroexcitation of giant resonances in 181Ta

    International Nuclear Information System (INIS)

    Hicks, R.S.; Auer, I.P.; Bergstrom, J.C.; Caplan, H.S.

    1977-01-01

    The giant resonance region of 181 Ta has been investigated by means of inelastic electron scattering with primary electron energies of 79.1 to 118.3 MeV. A peak-fitting procedure was employed to separate the measured spectrum into nine different resonance components. Multipolarity and strength assignments were deduced using DWBA analysis with the Goldhaber-Teller and Steinwedel-Jensen models. In addition to the well-known giant dipole structure, other resonances were identified at 23.2+-0.3 MeV (E2), 9.5+-0.2 and 11.5+-0.2 MeV (E2 or E0), 19.5+-0.8 MeV (E3), 3.70+-0.14 MeV (E3 or E4), and 5.40+-0.15 MeV (E4 or E5). The model dependence of the analysis is discussed. (Auth.)

  14. Study of giant resonances in heavy nuclei

    International Nuclear Information System (INIS)

    Cataldi, M.I.C.

    1986-01-01

    The electrodisintegration cross section for 181 Ta, 208 Pb and 209 Bi was measured by counting the emitted neutrons, with incident electrons in the energy range 8-22 MeV. The data was analysed using the virtual photon method, in order to obtain a multipole decomposition and the intensities of Magnetic Dipole and Electric Quadrupole, isoscalar and isovector, in the Giant Resonance. The results obtained for the isovector Giant Quadrupole Resonance are compared with the measured photodisintegration cross section, using data from Saclay and Livermore. This comparision indicates that the photodisintegration data can be well explained assuming an isovector E2 Resonance located between 120 and 130 A -1/3 MeV, with an intensity of one isovector E2 sum. (author) [pt

  15. Internal pair decay of giant resonances- signature from ISGMR in hot and heavy nucleus?

    International Nuclear Information System (INIS)

    Banerjee, S.R.

    1996-01-01

    The experimental observation of isoscalar giant monopole resonance built on highly excited nuclear states is still eluding the experimental nuclear physicists although a lot of effort has been put into it. Two very highly sophisticated specific detector systems had been constructed for this study and intense experimental activities were indulged in. Stony Brook pair detector array is being augmented currently to cover about 60% solid angle. There will be another spate of experimental activities and new results will be coming in, but presently there is no experimental observation of ISGMR in hot nucleus

  16. Photon scattering by the giant dipole resonance

    International Nuclear Information System (INIS)

    Bowles, T.J.; Holt, R.J.; Jackson, H.E.; McKeown, R.D.; Specht, J.R.

    1979-01-01

    Although many features of the giant dipole resonance are well known, the coupling between the basic dipole oscillation and other nuclear collective degrees of freedom such as surface vibrations and rotations is poorly understood. This aspect was investigated by elastic and inelastic bremsstrahlung scattering of tagged photons over the energy range 15 to 22 MeV. Target nuclei were 60 Ni, 52 Cr, 56 Fe, 92 Mo, and 96 Mo. Scattering and absorption cross sections are tabulated, along with parameters obtained from a two-Lorentzian analysis of the scattering cross sections; measured spectra are shown. It was necessary to remove Thomson scattering from the experimental results. It was found that coupling to surface vibrations in the giant dipole resonance is much weaker than the dynamic collective model suggests. The elastic scattering cross section for all targets but 60 Ni showed structure that is not evident in the absorption cross section measurement. 12 figures, 2 tables

  17. Triple Giant Resonance Excitations: A Microscopic Approach

    International Nuclear Information System (INIS)

    Lanza, E.G.; Andres, M.V.; Catara, F.; Chomaz, Ph.; Fallot, M.; Scarpaci, J.A.

    2007-01-01

    We present, for the first time, microscopic calculations of inelastic cross sections of the triple excitation of giant resonances induced by heavy ion probes. We start from a microscopic approach based on RPA. The mixing of three-phonon states among themselves and with two- and one-phonon states is considered within a boson expansion with Pauli corrections. In this way we go beyond the standard harmonic approximations and get anharmonic excitation spectra. At the same time we also introduce non-linearities in the external field. The calculations are done by solving semiclassical coupled channel equations, the channels being superpositions of one-, two- and three-phonon states. Previous calculations for the Double Giant Resonance excitation show good agreement with experimental cross sections. The inclusion of the three phonon components confirms the previous results for the DGR and produces a strong increase in the Triple GR energy region

  18. Giant resonance effects in radiative capture

    International Nuclear Information System (INIS)

    Snover, K.A.

    1979-01-01

    The technique of capture reaction studies of giant resonance properties is described, and a number of examples are given. Most of the recent work of interest has been in proton capture, in part because of the great utility (and availability) of polarized beams; most of the discussion concerns this reaction. Alpha capture, which has been a useful tool for exploring isoscalar E2 strength, and neutron capture are, however, also treated. 46 references, 14 figures

  19. Isotopic dependence of giant multipole resonances

    International Nuclear Information System (INIS)

    Bar Touv, J.; Moalem, A.; Shlomo, S.

    1980-01-01

    A procedure is presented which allows the application of linear response theory and the random phase approximation to an open shell. The procedure is applied to Ca isotopes. The general features of giant multipole resonances are found to vary smoothly with the mass. The resonances exhibit more structure in the open lfsub(7/2) shell nuclei. While the energy-weighted dipole sum is practically constant in all isotopes, the isoscalar quadrupole and octupole energy weighted sums increase continuously by approx. 30% from 40 Ca to 48 Ca. (orig.)

  20. High temperature giant dipole and isoscalar resonances

    International Nuclear Information System (INIS)

    Navarro, J.; Barranco, M.; Garcias, F.; Suraud, E.

    1990-01-01

    We present a systematic study of the Giant Dipole Resonance (GDR) at high temperatures (T > ∼ 4 MeV) in the framework of a semi-classical approximation that uses the m 1 and m 3 RPA sum rules to estimate the GDR mean energy. We focus on the evolution with T of the collective nature of the GDR and of the L = 0,2,3 and 4 isoscalar resonances. We find that the GDR remains particularly collective at high T, suggesting that it might be possible to observe it experimentally even at temperatures close to the maximum one a nucleus can sustain

  1. Isoscalar and isovector giant resonances in a self-consistent phonon coupling approach

    Energy Technology Data Exchange (ETDEWEB)

    Lyutorovich, N.; Tselyaev, V. [Physical Faculty, St. Petersburg State University, RU-198504 St. Petersburg (Russian Federation); Speth, J., E-mail: J.Speth@fz-juelich.de [Institut für Kernphysik, Forschungszentrum Jülich, D-52425 Jülich (Germany); Krewald, S.; Grümmer, F. [Institut für Kernphysik, Forschungszentrum Jülich, D-52425 Jülich (Germany); Reinhard, P.-G. [Institut für Theoretische Physik II, Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany)

    2015-10-07

    We present fully self-consistent calculations of isoscalar giant monopole and quadrupole as well as isovector giant dipole resonances in heavy and light nuclei. The description is based on Skyrme energy-density functionals determining the static Hartree–Fock ground state and the excitation spectra within random-phase approximation (RPA) and RPA extended by including the quasiparticle-phonon coupling at the level of the time-blocking approximation (TBA). All matrix elements were derived consistently from the given energy-density functional and calculated without any approximation. As a new feature in these calculations, the single-particle continuum was included thus avoiding the artificial discretization usually implied in RPA and TBA. The step to include phonon coupling in TBA leads to small, but systematic, down shifts of the centroid energies of the giant resonances. These shifts are similar in size for all Skyrme parametrizations investigated here. After all, we demonstrate that one can find Skyrme parametrizations which deliver a good simultaneous reproduction of all three giant resonances within TBA.

  2. Isoscalar and isovector giant resonances in a self-consistent phonon coupling approach

    Directory of Open Access Journals (Sweden)

    N. Lyutorovich

    2015-10-01

    Full Text Available We present fully self-consistent calculations of isoscalar giant monopole and quadrupole as well as isovector giant dipole resonances in heavy and light nuclei. The description is based on Skyrme energy-density functionals determining the static Hartree–Fock ground state and the excitation spectra within random-phase approximation (RPA and RPA extended by including the quasiparticle-phonon coupling at the level of the time-blocking approximation (TBA. All matrix elements were derived consistently from the given energy-density functional and calculated without any approximation. As a new feature in these calculations, the single-particle continuum was included thus avoiding the artificial discretization usually implied in RPA and TBA. The step to include phonon coupling in TBA leads to small, but systematic, down shifts of the centroid energies of the giant resonances. These shifts are similar in size for all Skyrme parametrizations investigated here. After all, we demonstrate that one can find Skyrme parametrizations which deliver a good simultaneous reproduction of all three giant resonances within TBA.

  3. Actual problems of giant resonance physics

    International Nuclear Information System (INIS)

    Zhalov, M.B.; Sliv, L.A.

    1982-01-01

    The raper deals with the discussion of theoretical problems associated with investigation into nuclear giant multipole resoonances (GMR). Analysis of test data on inelastic scattering of particles on nuclei is carried out to obtain the main GMR characteristics from the present experimental data. Giant isoscalar resonances and their structures in the random phase approximatmion (RPA) with Skyrm forces described by the microscopic theory are discussed. Cross section of 40 Ca excitation in reaction of α-particle inelastic scattering calculated in RPA with exact accountancy of one-nucleon continuum is graphically displayed as an example. Modified RPA used for calculation of GMR width is suggested. Conducted is comparison of energies of 40 Ca, 58 Ni, 90 Zr, 208 Pb nuclei isoscalar resonances calculated in RPA and their contributions to energy weighted sum rule the results of which are tabulated. Integral strength of resonance excitation in RPA by inelastic-scattered α particles and protons on 40 Ca and 208 Pb nuclei is considered. Channels of GMR disintegration are discussed. The most significant theoretical and experimental problems the solution of which is necessary for complete investigation of GMR are pointed out

  4. Temperature dependence of giant dipole resonance width

    International Nuclear Information System (INIS)

    Vdovin, A.I.; Storozhenko, A.N.

    2005-01-01

    The quasiparticle-phonon nuclear model extended to finite temperature within the framework of the thermo field dynamics is applied to calculate a temperature dependence of the spreading width Γ d own of a giant dipole resonance. Numerical calculations are made for 12S n and 208 Pb nuclei. It is found that the width Γ d own increases with T. The reason of this effect is discussed as well as a relation of the present approach to other ones existing in the literature

  5. Collective Hamiltonians for dipole giant resonances

    International Nuclear Information System (INIS)

    Weiss, L.I.

    1991-07-01

    The collective hamiltonian for the Giant Dipole resonance (GDR), in the Goldhaber-Teller-Model, is analytically constructed using the semiclassical and generator coordinates method. Initially a conveniently parametrized set of many body wave functions and a microscopic hamiltonian, the Skyrme hamiltonian - are used. These collective Hamiltonians are applied to the investigation of the GDR, in He 4 , O 16 and Ca 40 nuclei. Also the energies and spectra of the GDR are obtained in these nuclei. The two sets of results are compared, and the zero point energy effects analysed. (author)

  6. Surface and temperature effects in isovector giant resonances

    International Nuclear Information System (INIS)

    Lipparini, E.; Stringari, S.

    1988-01-01

    Using the liquid droplet model (LDM) we investigate three different sum rules for the isovector dipole and monopole excitations. Analytical formulae are derived for the excitation energies of these resonances and the predictions are compared with experiments. The role of the surface and the effects of temperature are explicitly discussed. (orig.)

  7. Giant resonances in hot rotating nuclei

    International Nuclear Information System (INIS)

    Ring, P.

    1992-01-01

    Present theoretical descriptions of the giant resonances in hot rotating nuclei are reviewed. Mean field theory is used as a basis for the description of the hot compound states. Starting from the static solution at finite temperature and with fixed angular momentum small amplitude collective vibrations are calculated in the frame work of finite temperature random phase approximation for quasi-particles. The effect of pairing at low temperatures as well as the effect of rotations on the position of the resonance maxima are investigated. Microscopic and phenomenological descriptions of the damping mechanisms are reviewed. In particular it turns out that fluctuations play an important role in understanding of the behaviour of the width as a function of the temperature. Motional narrowing is critically discussed. (author). 99 refs., 5 figs

  8. Condensed matter view of giant resonance phenomena

    International Nuclear Information System (INIS)

    Zangwill, A.

    1987-01-01

    The intent of this article is to present a view of giant resonance phenomena (an essentially atomic phenomenon) from the perspective of a condensed matter physicist with an interest in the optical properties of matter. As we shall see, this amounts to a particular prejudice about how one should think about many-body effects in a system of interacting electrons. Some of these effects are special to condensed matter systems and will be dealt with in the second half of this paper. However, it turns out that the authors view of the main ingredient to a giant resonance differs significantly from that normally taken by scientists trained in the traditional methods of atomic physics. Therefore, in the first section the author will take advantage of the fact that his contribution to this volume was composed and delivered to the publishers somewhat after the conclusion of the School (rather than before as requested by the organizers) and try to clearly distinguish the differences of opinion presented by the lecturers from the unalterable experimental facts. 46 references, 9 figures

  9. Decay of giant resonance E2 isoscalar in heavy nuclei

    International Nuclear Information System (INIS)

    Herdade, S.B.

    1980-01-01

    In this work, it is made a study of the giant resonance E2 isoscalar, in heavy nuclei. Fission probabilities for this resonance were determined by various authors, in different experiments, for 238 U. (A.C.A.S.) [pt

  10. New properties of giant resonances in highly excited nuclei

    International Nuclear Information System (INIS)

    Morsch, H.P.

    1991-01-01

    Studies on the giant dipole resonance in very hot nuclei investigated in heavy ion-induced particle-γ coincidence experiments are reviewed. A signature is found in the γ-decay of excited nuceli which shows direct decay of the giant dipole resonance. This provides a new dimension in giant resonance studies and the possibility to study the dependence of giant resonance energy, width and sum rule strength on excitation energy and rotation of the system. Further, the fact that the giant resonance splits in deformed nuclei provides a unique way to get information on the shape of hot nuclei. First results are obtained on the following questions: (i)What is the nuclear shape at high temperature (T≥2 MeV)? (ii)Is there a phase transition in the nuclear shape at T∼1.7 MeV? (iii)Does motional narrowing exist in hot nuclei? (author). 19 refs., 11 figs

  11. Semimicroscopic description of the giant quadrupole resonances in deformed nuclei

    International Nuclear Information System (INIS)

    Kurchev, G.; Malov, L.A.; Nesterenko, V.O.; Soloviev, V.G.

    1976-01-01

    The calculation results of the giant quadrupole isoscalar and isovector resonances performed within the random phase approximation are represented. The strength functions for E2-transitions are calculated for doubly even deformed nuclei in the regions 150 (<=) A < 190 and 228 (<=) A < 248 in the energy interval (0-40) MeV. The following integral characteristics of giant quadrupole resonances are obtained: the position, widths, the contribution to the energy weighted sum rule and the contribution to the total cross section of photoabsorption. The calculations have shown that giant quadrupole resonances are common for all the considered nuclei. The calculated characteristics of the isoscalar giant quadrupole resonance agree with the available experimental data. The calculations also show that the semimicroscopic theory can be successfully applied for the description of giant multipole resonances

  12. Nuclear isovector giant resonances excited by pion single charge exchange

    International Nuclear Information System (INIS)

    King, B.H.

    1993-07-01

    This thesis is an experimental study of isovector giant resonances in light nuclei excited by pion single charge exchange reactions. Giant dipole resonances in light nuclei are known to be highly structured. For the mass 9 and 13 giant dipole resonances, isospin considerations were found to be very important to understanding this structure. by comparing the excitation functions from cross section measurements of the (π + , π 0 ) and (π, π 0 ) inclusive reactions, the authors determined the dominant isospin structure of the analog IVGR's. The comparison was made after decomposing the cross section into resonant and non-resonant components. This decomposition is made in the framework of strong absorption and quasi-free scattering. Measurements in the region of the isovector giant dipole resonances (IVGDR) were made to cover the inclusive angular distributions out to the second minimum. Study of the giant resonance decay process provides further understanding of the resonances. This study was carried out by observing the (π + , π 0 p) coincident reactions involving the resonances of 9 B and 13 N excited from 9 Be and 13 C nuclei. These measurements determined the spectra of the decay protons. This method also permitted a decomposition of the giant resonances into their isospin components. The multipolarities of the resonances were revealed by the decay proton angular correlations which, for dipoles, are of the form 1 + A 2 P 2 (cos θ)

  13. Investigation of the energy-averaged double transition density of isoscalar monopole excitations in medium-heavy mass spherical nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Gorelik, M.L.; Shlomo, S. [National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation); Cyclotron Institute, Texas A& M University, College Station, TX 77843 (United States); Tulupov, B.A. [National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation); Institute for Nuclear Research, RAS, Moscow 117312 (Russian Federation); Urin, M.H., E-mail: urin@theor.mephi.ru [National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation)

    2016-11-15

    The particle–hole dispersive optical model, developed recently, is applied to study properties of high-energy isoscalar monopole excitations in medium-heavy mass spherical nuclei. The energy-averaged strength functions of the isoscalar giant monopole resonance and its overtone in {sup 208}Pb are analyzed. In particular, we analyze the energy-averaged isoscalar monopole double transition density, the key quantity in the description of the hadron–nucleus inelastic scattering, and studied the validity of the factorization approximation using semi classical and microscopic one body transition densities, respectively, in calculating the cross sections for the excitation of isoscalar giant resonances by inelastic alpha scattering.

  14. Features of the giant E1 resonance

    International Nuclear Information System (INIS)

    Bergere, R.

    1976-01-01

    Since most of the available experimental data concerning the giant dipole E1 resonance (GDR) have been obtained with real photons, the characteristics of real photon sources are reviewed with an attempt to connect the experimental particularities of each of them to the specific parameters of the GDR which it is best suited to reach. Some systematic properties gathered from experimental data of GDR (average energy, splitting and broadening of the GDR) are compared with the predictions of the static and dynamic collective models of the nuclei. The position in energy and the fine structure of the GDR are more closely connected to shell model predictions as nuclei get lighter, the various experimental integrated cross sections being also more easily understood by comparisons with microscopic models. Most of the reported data refer to the doorway state through which GDR is excited, however the competition between the decay channels for GDR states is also emphasized

  15. Spin isovector giant resonances in (n,p) reactions

    International Nuclear Information System (INIS)

    Spicer, B.M.

    1997-01-01

    The present status of the study of spin-flip isovector giant resonances, using the (n,p) charge exchange reaction, is reviewed. After a brief history of the discovery of these giant resonances, a critical appraisal of the interpretation of the data in terms of giant resonances is given, along with some of the theoretical advances that impact on the interpretation of these data. A sampling of the results obtained for typical targets is given, followed by the interpretation of these results. A brief statement is made concerning the way forward in experimental technique for nuclear structure research using charge exchange reactions

  16. Excitation of giant resonances via charge exchange reactions

    International Nuclear Information System (INIS)

    Goodman, C.D.

    1979-01-01

    Charge-exchange reactions can be useful for identifying isovector resonances. At present the most promising use of charge-exchange reactions with respect to giant resonances is to locate and study Gamow-Teller (GT) resonances. Detailed comparisons between GT and M1 strengths can yield further structure information. 7 figures

  17. Nuclear elasticity applied to giant resonances of fast rotating nuclei

    International Nuclear Information System (INIS)

    Jang, S.; Bouyssy, A.

    1987-06-01

    Isoscalar giant resonances in fast rotating nuclei are investigated within the framework of nuclear elasticity by solving the equation of motion of elastic nuclear medium in a rotating frame of reference. Both Coriolis and centrifugal forces are taken into account. The nuclear rotation removes completely the azimuthal degeneracy of the giant resonance energies. Realistic large values of the angular velocity, which are still small as compared to the giant resonance frequencies, are briefly reviewed in relation to allowed high angular momenta. It is shown that for the A=150 region, the Coriolis force is dominating for small values (< ∼ 0.05) of the ratio of angular velocity to resonance frequency, whereas the centrifugal force plays a prominent part in the shift of the split resonance energies for larger values of the ratio. Typical examples of the resonance energies and their fragmentation due to both rotation and deformation are given

  18. Fluid dynamics of giant resonances on high spin states

    International Nuclear Information System (INIS)

    Di Nardo, M.; Di Toro, M.; Giansiracusa, G.; Lombardo, U.; Russo, G.

    1983-01-01

    We describe giant resonances built on high spin states along the yrast line as scaling solutions of a linearized Vlasov equation in a rotating frame obtained from a TDHF theory in phase space. For oblate cranked solutions we get a shift and a splitting of the isoscalar giant resonances in terms of the angular velocity. Results are shown for 40 Ca and 168 Er. The relative CM strengths are also calculated. (orig.)

  19. Giant resonances in free atoms and in clusters

    International Nuclear Information System (INIS)

    Brechignac, C.; Connerade, J.P.

    1994-01-01

    A review of recent developments in the study of giant resonances in free atoms and in clusters is presented, with particular emphasis on the transition from free atoms to atoms in the condensed phase. Giant resonances in alkali and related metallic clusters due to the excitation of closed shells of delocalized electrons are also reviewed and the relation between different types of collective oscillations is discussed. (author)

  20. Direct vs statistical decay of nuclear giant multipole resonances

    International Nuclear Information System (INIS)

    Dias, H.; Hussein, M.S.; Carlson, B.V.; Merchant, A.C.; Adhikari, S.K.

    1986-01-01

    A theoretical framework for the description of the decay of giant multipole resonances id developed. Besides the direct decay, both the pre-equilibrium and statistical (compound) decays are taken into account in a consistent way. It is shown that the statistical decay of the giant resonance is not necessarily described by the Hauser-Feshbach theory owing to the presence of a mixing parameter, which measures the degree of fragmentation. Applications are made to several cases. (Author) [pt

  1. Giant 4p-quadrupole resonances in the Rare Earths

    International Nuclear Information System (INIS)

    Matthew, J.A.D.; Netzer, F.P.; Clark, C.W.; Morar, J.F.

    1987-01-01

    X-ray absorption of Ce obtained by partial secondary yield, is compared with previously obtained electron-energy loss measurements in reflection mode. The absence of a strong feature below 4p 3/2 threshold in photon absorption provides confirmation that the peak in EELS is nondipole in character. Theoretical analysis supports interpretation in terms of a p-f giant quadrupole resonance, a result which broadens the analogy between giant resonances in atomic and nuclear physics

  2. Giant dipole resonance in hot rotating nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarty, D.R. [Bhabha Atomic Research Centre, Nuclear Physics Division, Mumbai (India); Dinh Dang, N. [RIKEN, Nishina Centre for Accelerator-based Science, Saitama (Japan); VINATOM, Institute of Nuclear Science and Technique, Hanoi (Viet Nam); Datar, V.M. [Tata Institute of Fundamental Research, INO Cell, Mumbai (India)

    2016-05-15

    Over the last several decades, extensive experimental and theoretical work has been done on the giant dipole resonance (GDR) in excited nuclei covering a wide range of temperature (T), angular momentum (J) and nuclear mass. A reasonable stability of the GDR centroid energy and an increase of the GDR width with T (in the range∝1-3 MeV) and J are the two well-established results. Some experiments have indicated the saturation of the GDR width at high T. The gradual disappearance of the GDR vibration at much higher T has been observed. Experiments on the Jacobi transition and the GDR built on superdeformed shapes at high rotational frequencies have been reported in a few cases. Theoretical calculations on the damping of the collective dipole vibration, characterised by the GDR width, have been carried out within various models such as the thermal shape fluctuation model and the phonon damping model. These models offer different interpretations of the variation of the GDR width with T and J and have met with varying degrees of success in explaining the experimental data. In this review, the present experimental and theoretical status in this field is discussed along with the future outlook. The interesting phenomenon of the pre-equilibrium GDR excitation in nuclear reactions is briefly addressed. (orig.)

  3. Giant resonances in atoms and in fluorine cage molecules

    International Nuclear Information System (INIS)

    Mansfield, M.W.D.

    1987-01-01

    Giant resonances in the photoabsorption spectra of atoms occur in the extreme ultraviolet region of the electromagnetic spectrum. In order to observe absorption spectra in this region it is necessary to generate columns of atomic vapor which will often by very hot and chemically aggressive, and to contain them without solid windows between two regions of high vacuum, the spectrometer and the light source, usually an electron synchrotron. The technical problems are often formidable so that although it had long been recognized that giant resonances in solid lanthanides were essentially atomic phenomena (Fomichev et al. 1967, Dehmer et al. 1971) earlier investigations of giant resonances in atoms were limited to the more manageable elements which precede the transition rows, the inert gases, alkali and alkaline earth elements. In this paper the authors discusses the spectra of transition row atoms in order of decreasing localization (Smith and Kmetko 1983) viz. 4d → f, 5d → f, 3p → d, 4p → d and 5p → d. He tends to avoid discussion of the giant resonances themselves because their profiles and interpretation will be discussed comprehensively by other contributors. Instead he concentrates on the detailed analyses which have been attempted of the discrete structure which usually accompanies giant resonances in atoms. Interpretation of this structure can provide accurate determinations of thresholds for inner shell excitation in atoms and can also be used to anticipate structure which may overlie the giant resonances and distort their profiles. 75 references, 21 figures

  4. Excitation and photon decay of giant multipole resonances

    International Nuclear Information System (INIS)

    Bertrand, F.E.; Beene, J.R.

    1990-01-01

    A brief review of the excitation of giant multipole resonances via Coulomb excitation is given which emphasizes the very large cross sections that can be realized through this reaction for both isoscalar and isovector resonances. Discussion and results where available, are provide for the measurement of the photon decay of one and two phonon giant resonances. It is pointed out throughout the presentation that the use of E1 photons as a ''tag'' provides a means to observe weakly excited resonances that cannot be observed in the singles spectra. 14 refs., 12 figs., 1 tab

  5. New results on multiple excitations of giant resonances

    International Nuclear Information System (INIS)

    Mordechai, S.; Texas Univ., Austin, TX; Moore, C.F.

    1993-01-01

    Exotic excitations like the double giant dipole were predicted for many years but not observed experimentally until recently. Several experiments have been carried out at Los Alamos National laboratory to search for these new collective modes of the nucleus. The results discover two previously unobserved types of double giant resonances. This work presents the recent pion double charge exchange data and the analysis that support the existence of two such exotic vibrational nuclear modes

  6. Is There a Pronounced Giant Dipole Resonance in 4He?

    International Nuclear Information System (INIS)

    Efros, V.D.; Efros, V.D.; Leidemann, W.; Orlandini, G.; Orlandini, G.

    1997-01-01

    A four-nucleon calculation of the total 4 He photodisintegration cross section is performed. The full final-state interaction is taken into account for the first time. This is achieved via the method of the Lorentz integral transform. Semirealistic NN interactions are employed. Different from the known partial two-body 4 He( γ,n) 3 He and 4 He( γ,p) 3 H cross sections our total cross section exhibits a pronounced giant resonance. Thus, in contrast to older (γ,np) data, we predict quite a strong contribution of the (γ,np) channel at the giant resonance peak energy. copyright 1997 The American Physical Society

  7. Relativistic Coulomb excitation of giant resonances in the hydrodynamic model

    International Nuclear Information System (INIS)

    Vasconcellos Gomes, Ana Cristina de.

    1990-05-01

    We investigate the Coulomb excitation of giant dipole resonances in relativistic heavy ion collisions using a macroscopic hydrodynamical model for the harmonic vibrations of the nuclear fluid. The motion is treated as a combination of the Goldhaber-Teller displacement mode and the Steinwedel-Jensen acoustic mode, and the restoring forces are calculated using the droplet model. This model is used as input to study the characteristics of multiple excitation of giant dipole resonances in nuclei. Possible signatures for the existence of such states are also discussed quantitatively. (author). 52 refs., 14 figs., 3 tabs

  8. A density variational approach to nuclear giant resonances at zero and finite temperature

    International Nuclear Information System (INIS)

    Gleissl, P.; Brack, M.; Quentin, P.; Meyer, J.

    1989-02-01

    We present a density functional approach to the description of nuclear giant resonances (GR), using Skyrme type effective interactions. We exploit hereby the theorems of Thouless and others, relating RPA sum rules to static (constrained) Hartree-Fock expectation values. The latter are calculated both microscopically and, where shell effects are small enough to allow it, semiclassically by a density variational method employing the gradient-expanded density functionals of the extended Thomas-Fermi model. We obtain an excellent overall description of both systematics and detailed isotopic dependence of GR energies, in particular with the Skyrme force SkM. For the breathing modes (isoscalar and isovector giant monopole modes), and to some extent also for the isovector dipole mode, the A-dependence of the experimental peak energies is better described by coupling two different modes (corresponding to two different excitation operators) of the same spin and parity and evaluating the eigenmodes of the coupled system. Our calculations are also extended to highly excited nuclei (without angular momentum) and the temperature dependence of the various GR energies is discussed

  9. A Boltzmann equation approach to the damping of giant resonances in nuclei

    International Nuclear Information System (INIS)

    Schuck, P.; Winter, J.

    1983-01-01

    The Vlasov equation plus collision term (Boltzmann equation) represents an appropriate frame for the treatment of giant resonances (zero sound modes) in nuclei. With no adjustable parameters we obtain correct positions and widths for the giant quadrupole resonances. (author)

  10. Magnetic monopoles

    International Nuclear Information System (INIS)

    Fryberger, D.

    1984-12-01

    In this talk on magnetic monopoles, first the author briefly reviews some historical background; then, the author describes what several different types of monopoles might look like; and finally the author discusses the experimental situation. 81 references

  11. A self-consistent semiclassical sum rule approach to the average properties of giant resonances

    International Nuclear Information System (INIS)

    Li Guoqiang; Xu Gongou

    1990-01-01

    The average energies of isovector giant resonances and the widths of isoscalar giant resonances are evaluated with the help of a self-consistent semiclassical Sum rule approach. The comparison of the present results with the experimental ones justifies the self-consistent semiclassical sum rule approach to the average properties of giant resonances

  12. Resonant Excitation of a Truncated Metamaterial Cylindrical Shell by a Thin Wire Monopole

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Erentok, Aycan; Breinbjerg, Olav

    2009-01-01

    A truncated metamaterial cylindrical shell excited by a thin wire monopole is investigated using the integral equation technique as well as the finite element method. Simulations reveal a strong field singularity at the edge of the truncated cylindrical shell, which critically affects the matching...

  13. Electric giant resonances in sup 4 sup 0 Ca and sup 4 sup 8 Ca probed with electron and proton scattering coincidence experiments

    CERN Document Server

    Strauch, S

    1999-01-01

    Excitation and particle decay of electric giant resonances in sup 4 sup 0 Ca and sup 4 sup 8 Ca are studied with electron and proton beams. Recent results of a sup 4 sup 8 Ca(e,e'n) measurement performed at the S-DALINAC in Darmstadt with kinematics that selectively populate electric monopole, dipole and quadrupole excitations are presented. The extracted B(E1) strength distribution is in good agreement with photo nuclear data and the predictions of microscopic calculations. The summed B(E2+E0) strength distribution, however disagrees with the result of these calculations. The neutron emission of the giant dipole resonance in sup 4 sup 8 Ca shows a large fraction of direct decay to sup 4 sup 7 Ca hole states. In addition, isoscalar giant monopole resonance strength in sup 4 sup 0 Ca was extracted from (e,e'alpha sub 0) and (e,e'alpha sub 1) angular correlations. A study of the quadrupole strength in the alpha sub 0 decay channel of sup 4 sup 0 Ca with a (p,p'alpha) coincidence measurement reiterates the unsol...

  14. Structure of the giant dipole resonance in 208Pb

    International Nuclear Information System (INIS)

    El Naggar, N.M.

    1977-01-01

    A new scheme is devised to study the giant resonance in the heavy magic nucleus 208 Pb. The effect of the 4 + and 5 - collective excitations of the nucleus core is demonstrated. The calculated cross section is compared with the experimental data. (author)

  15. The natural line shape of the giant dipole resonance

    International Nuclear Information System (INIS)

    Gordon, E.F.; Pitthan, R.

    1977-01-01

    Investigation of photoabsorption experiments in the spherical nucleus 141 Pr, the quasispherical dynamically deformed 197 Au, and the statically deformed 165 Ho showed that the function which describes best the energy dependence of the reduced transition probability is given by the Breit-Wigner form rather than the Lorentz form. However, the form of the resulting measured cross section is approximately of the Lorentz type. The dependence of the giant resonance width GAMMA on the excitation energy was also investigated, and found to be less than 1% per MeV if one considered the known isovector E2 resonance above the giant dipole resonance. Best fit values of the reduced transition probabilities for the three nuclei are given and compared to (e,e') results. (Auth.)

  16. Electromagnetic excitation of the two-phonon giant dipole resonance

    International Nuclear Information System (INIS)

    Emling, H.

    1994-03-01

    It is the aim of this article to summarize our present knowledge on the double isovector giant dipole resonance (DGDR) and our understanding of the electromagnetic excitation mechanism in heavy ion collisions in the relativistic energy regime. In the following chapter, a brief resume on the history of giant resonances is given and, based on their understanding, conclusions on the expected properties of multi-phonon resonances are drawn. In chapter 2, the essential features of electromagnetic heavy ion interactions at (near) relativistic velocities will be illuminated and the theoretical framework is presented, which describes such processes. New experimental methods were required for an appropriate study of Coulomb dissociation processes, which are discussed in chapter 3 together with the experimental results. Chapter 4 is dedicated to summarize the results from electromagnetic excitation studies, to compare with those from alternative methods and, in particular, to contrast experimental findings with theoretical predictions and to address open problems. (orig.)

  17. Collisional width of giant resonances and interplay with Landau damping

    International Nuclear Information System (INIS)

    Bonasera, A.; Burgio, G.F.; Di Toro, M.; Wolter, H.H.

    1989-01-01

    We present a semiclassical method to calculate the widths of giant resonances. We solve a mean-field kinetic equation (Vlasov equation) with collision terms treated within the relaxation time approximation to construct a damped strength distribution for collective motions. The relaxation time is evaluated from the time evolution of distortions in the nucleon momentum distribution using a test-particle approach. The importance of an energy dependent nucleon-nucleon cross section is stressed. Results are shown for isoscalar giant quadrupole and octupole motions. A quite important interplay between self-consistent (Landau) and collisional damping is revealed

  18. The monopole and quadrupole vibrations of a hot nucleus

    International Nuclear Information System (INIS)

    Okolowicz, J.; Drozdz, S.; Ploszajczak, M.; Caurier, E.

    1989-03-01

    An extended time-dependent Hartree-Fock approach has been applied to a description of the isoscalar giant monopole and quadrupole vibration modes in the excited nuclear system at finite temperature. The temperature dependence of the resonance characteristics is established for both modes. In anticipation of some anharmonic effects the principle of regularity and single-valuedness has been used to extract the energies of the collective modes. (orig.)

  19. Fragmentation of giant dipole resonance at finite temperature

    International Nuclear Information System (INIS)

    Vdovin, A.

    2005-01-01

    It is well known that the main part of a width of a collective giant resonance built on the ground state in heavy nuclei is due to coupling of one-phonon vibrational states with more complex ones like two phonon or two-particle - two-hole. So it seems natural that the same idea was also explored in studying of the formation and dependence on temperature of a width of giant resonances built on a compound nuclear state. The first microscopic calculations of a giant dipole resonance width at finite temperature have demonstrated its weak dependence on T whereas the experimental width Γ exp strongly increases up to T≤3 MeV. The observed thermal behaviour of Γ exp was attributed mainly to thermal fluctuations of a nuclear shape at finite T . However, further theoretical studies of the problem have shown a strengthening of the GDR spreading with T. We calculate a fragmentation of the giant dipole resonance in hot spherical nuclei within the approach based on the quasiparticle-phonon model extended to finite temperature in with the formalism of thermofield dynamics. The fragmentation of collective giant dipole vibrations at finite T is due to the coupling with 'two-thermal phonon' configurations. The energies and structures of thermal phonon states are calculated from the thermal RPA temperature dependence of the variance σ th of a theoretical E1 strength function and the experimental GDR width Γ exp in 120 Sn. The coupling of thermal phonons is determined by their fermionic structure. The variance σ th of the E1 strength function is found continuously increasing with temperature. The main reason of this behavior is the coupling of the dipole phonons with very low-lying particle-particle (hole-hole) thermal phonons. These phonons are noncollective ones and they appear only at T≠0. The calculated T dependence of σ th is quite similar to that of the experimental width Γ exp in 120 Sn and 208 Pb

  20. Systematic study of the giant monopolar resonance via inelastic scattering of 108.5 MeV 3He. Measurement of the nuclear compressibility

    International Nuclear Information System (INIS)

    Lebrun, Didier.

    1981-09-01

    The giant monopole resonance has been studied via inelastic scattering of 108.5 MeV 3 He at very small angles (including 0 0 ) on approximately 50 nuclei. Its angular distribution reaches its maximum in this region and leads to clear separation with GQR. DWBA analysis shows a smooth increase of the strength from few per cent of the sum rule in light nuclei up to 100% in heavier ones. The excitation energy analysis shows a crossing effect of the monopole and quadrupole frequencies in A = 40-50 region, a coupling effect between the two modes in deformed nuclei, an asymmetry effect in several series of isotopes. Compressibility moduli of nuclear matter Ksub(infinity), surface Ksub(s) and asymmetry Ksub(tau) have seen extracted, as well as the Landau parameter F 0 at saturation [fr

  1. Excitation of giant resonances through inelastic scattering of 170 at 84 MeV/u. Fission decay of giant resonances

    International Nuclear Information System (INIS)

    Cabot, C.; Barrette, J.; Mark, S.K.; Turcotte, R.; Xing, J.; Van der Woude, A.; Van Den Berg, A. M.

    1991-01-01

    Inelastic scattering of 84 MeV/u 17 0 projectiles have been used to excite the giant resonances (GR) in various nuclei ranging from A=60 to A=232. For the isoscalar giant quadrupole resonance (ISGQR), the energy and width of the resonance, as well as the EWSR obtained from the measured cross sections, are in agreement with the known systematics for A>40. The observed GMR strengths are close to 100% EWRS and are consistent with other recent experimental results using heavy ion projectiles. These results lead to a somewhat different picture than that provided by previous studies using light projectiles. Strength is also observed at high excitation energy. The analysis of these resonances is in progress. Our study of the fission decay of GR in 232 Th leads to a somewhat different conclusion than previously deduced from data obtained with light ion projectiles, where no evidence for the fission decay of the ISGQR has been found. In the present work, due to the very good peak-to-continuum ratio, a structure is observed in the fission coincidence spectrum around 10 MeV which can be attributed to the fission decay of giant resonances. The measured fission probability is consistent with a statistical decay of the ISGQR. 10 figs

  2. Study of giant multipole resonances in 40Ca

    International Nuclear Information System (INIS)

    Rost, H.

    1979-01-01

    In the present thesis giant resonance states in 40 Ca were studied by scattering of 104 MeV a particles on 40 Ca and by the reactions 39 K(p vector,p') 39 K and 39 K(p,α) 36 Ar. The scattered α-particles were measured at extreme forward angles (THETAsub(L) = 4 0 -16 0 C), because at forward angles the cross sections for the excitation of states with spin 0 and 1 strongly differ from those with higher spin. The aim of this experiment was first of all the study of the giant resonance region in 40 Ca on the contribution to 0 + or 1 - states. Beside the known electric giant quadrupole resonances at Esub(x) approx. equal to 18.5 MeV (25% EWSR) contributions of EO-strength at Esub(x) approx. equal to 21 MeV (6% EWSR) and indications to a (isoscalar) E1-strength at Esub(x) approx. equal to 14 MeV and Esub(x) approx. equal to 16 MeV were found. At the reactions 39 K(p vector,p') 39 K and 39 K(p,α) 36 Ar in the channels (p,p 0 ),(p,p 4 ), (p,αsub(o)), and (p,α 1 ) at incident energies at about 10 MeV (Esub(x)( 40 Ca) approx. equal to 18 MeV) resonant structures were observed. A scattering phase analysis performed for the elastic proton scattering didn't however yield quantitative results about the resonance parameter. An expansion of the cross sections by Legendre polynomials for the remaining reaction channel didn't allow a conclusion about the dominance of a certain L-value. The only indication to the connection of the observed resonant structures with the giant quadrupole resonance in 40 Ca is therefore the energetic position at about Esub(x) approx. equal to 18 MeV. Altogether the observed structures however were not very pronounced, so it can be concluded, that the excitation of the giant quadrupole resonance in 40 Ca by protons via the ground state of 39 K occurs not very strongly. (orig./HSI) [de

  3. Overtones of isoscalar giant resonances studied in direct particle decay measurements

    NARCIS (Netherlands)

    Hunyadi, M; van den Berg, AM; Csatlos, M; Csige, L; Davids, B; Garg, U; Gulyas, J; Harakeh, MN; de Huu, MA; Krasznahorkay, A; Sohler, D; Wortche, HJ

    The isoscalar giant dipole resonance (ISGDR), which is the lowest-energy overtone mode of the isoscalar giant resonances, has been studied in some medium-heavy and heavy nuclei in coincidence measurements. The observation of the direct nucleon decay channels significantly helped to enhance giant

  4. Observation of the M1 giant resonance by resonance averaging in 106Pd

    International Nuclear Information System (INIS)

    Kopecky, J.

    1987-01-01

    An investigation of capture of 2 keV and 24 keV neutrons in a 105 Pd target resulted in resonance-averaged intensities of primary gamma rays with energies between 5.2 and 9.5 MeV. From these intensities the gamma ray strength functions have been evaluated for E1, M1 and E2 radiation and compared with predictions of the giant resonance theory. The inclusion of an energy dependent spreading width for the E1 giant resonance is necessary. The energy distribution of M1 reduced strength is consistent with an interpretation of a broad resonance around 8.8 MeV. E2 data agrees satisfactorily with the giant extrapolation. (orig.)

  5. Magnetic monopoles

    International Nuclear Information System (INIS)

    Shnir, Ya.M.

    2005-01-01

    This monograph addresses the field theoretical aspects of magnetic monopoles. Written for graduate students as well as researchers, the author demonstrates the interplay between mathematics and physics. He delves into details as necessary and develops many techniques that find applications in modern theoretical physics. This introduction to the basic ideas used for the description and construction of monopoles is also the first coherent presentation of the concept of magnetic monopoles. It arises in many different contexts in modern theoretical physics, from classical mechanics and electrodynamics to multidimensional branes. The book summarizes the present status of the theory and gives an extensive but carefully selected bibliography on the subject. The first part deals with the Dirac monopole, followed in part two by the monopole in non-abelian gauge theories. The third part is devoted to monopoles in supersymmetric Yang-Mills theories. (orig.)

  6. Magnetic monopoles

    International Nuclear Information System (INIS)

    Preskill, J

    1984-01-01

    This article offers a review of the physics of the magnetic monopole, which, although as yet unseen, offers sound theoretical reasons to believe that it must exist. Several theories are presented and equations are given. The idea that magnetic monopoles, stable particles carrying magnetic charges, ought to exist has, according to the authors, proved to be very durable. One theory presented demonstrates the consistency of magnetic monopoles with quantum electrodynamics. Another theory demonstrates the necessity of monopoles in grand unified gauge theories. The authors believe it is reasonable to expect the monopole to be an extremely heavy stable elementary particle. The stability of the classical monopole solution given is ensured by a topological principle explained

  7. The width of the giant dipole resonance at finite temperature

    International Nuclear Information System (INIS)

    Mau, N.V.

    1992-01-01

    A method is proposed to evaluate the effect of the change of the Fermi sea on the width of the giant dipole resonance at finite temperature. In a schematic model it is found that, indeed, in 208 Pb the width increases very sharply up to about T=4 MeV but shows a much weaker variation for higher temperature. (author) 26 refs., 7 figs., 2 tabs

  8. Temperature dependence of spreading width of giant dipole resonance

    International Nuclear Information System (INIS)

    Storozhenko, A.N.; Vdovin, A.I.; Ventura, A.; Blokhin, A.I.

    2002-01-01

    The Quasiparticle-Phonon Nuclear Model extended to finite temperature within the framework of Thermo Field Dynamics is applied to calculate a temperature dependence of the spreading width Γ ↓ of a giant dipole resonance. Numerical calculations are made for 120 Sn and 208 Pb nuclei. It is found that Γ ↓ increases with T. The reason of this effect is discussed as well as a relation of the present approach to other ones, existing in the literature

  9. Quantized TDHF for isoscalar giant quadrupole resonances in spherical nuclei

    International Nuclear Information System (INIS)

    Drozdz, S.; Okolowicz, J.; Ploszajczak, M.; Caurier, E.

    1988-01-01

    The time-dependent Hartree-Fock theory supplemented with the regularity and single-valuedness quantization condition for the gauge invariant component of the wavefunction is applied to the description of the centroid energy and escape width of isoscalar giant quadrupole resonances in 16 O, 40 Ca and 110 Zr. Calculations are performed using the Skyrme SIII effective interaction. An important role of the finite oscillation amplitude in the mean-field dynamics is emphasized. (orig.)

  10. Direct vs statistical decay of nuclear giant multipole resonances

    International Nuclear Information System (INIS)

    Hussein, M.S.

    1986-07-01

    A theoretical framework for the description of the decay of giant multipole resonances is developed. Besides the direct decay, both the pre-equilibrium and statistical (compound) decays are taken into account in a consistent way. It is shown that the statistical decay of the GR is not necessarily correctly described by the Hauser-Feshbach theory owing to the presence of a mixing parameter, which measures the degree of fragmentation. Applications are made to several cases. (Author) [pt

  11. Statistical decay of the E1 giant resonance

    International Nuclear Information System (INIS)

    Teruya, N.; Dias, H.; Wolynec, E.

    1987-10-01

    Available esperimental data on neutron decay spectra from the E1 giant resonances in 208 Pb and 209 Bi are compared with the predicted spectra for statistical decay. The calculations are performed using the Hauser-Feshbach formalism with the experimental levels of the residual nuclei. The particle-vibrator model is used to assign spins and parities to experimental levels when those are unknown and also to predict the levels where there is not enough experimental information. (author) [pt

  12. Giant right atrial myxoma: characterization with cardiac magnetic resonance imaging.

    LENUS (Irish Health Repository)

    Ridge, Carole A

    2012-02-01

    A 53-year-old woman presented to the emergency department with a 2-week history of dyspnoea and chest pain. Computed tomography pulmonary angiography was performed to exclude acute pulmonary embolism (PE). This demonstrated a large right atrial mass and no evidence of PE. Transthoracic echocardiography followed by cardiac magnetic resonance imaging confirmed a mobile right atrial mass. Surgical resection was then performed confirming a giant right atrial myxoma. We describe the typical clinical, radiologic, and pathologic features of right atrial myxoma.

  13. Optimization experiments on the study of giant resonance in nuclei

    International Nuclear Information System (INIS)

    Lyubarskij, G.Ya.; Savitskij, G.A.; Fartushnyj, V.A.; Khazhmuradov, M.A.; Levandovskij, S.P.

    1988-01-01

    Optimum choice of the target exposure to a beam in experiments on the study of giant resonances in nuclei is considered. Optimization is aimed at reducing mean square errors of defined formfactors. Four different optimization quality criteria - variances of four form factor experimental values are considered. Variances resulting form optimization are 1.5-2 times as less as variances in real experiment. The effect of experiment design optimization criterion on form factors determination errors is ascertained. 1 ref.; 3 tabs

  14. Theoretical Predictions of Giant Resonances in 94Mo

    Science.gov (United States)

    Golden, Matthew; Bonasera, Giacomo; Shlomo, Shalom

    2016-09-01

    We perform Hartree-Fock based Random Phase Approximation using thirty-three common Skyrme interactions found in the literature for 94Mo. We calculate the strength functions and the Centroid Energies of the Isoscalar Giant Resonances for all multipolarities L0, L1, L2, L3. We compare the calculated Centroid Energies with the experimental value; we also study the Centroid Energy and any correlation it may have with the Nuclear Matter properties of each interaction.

  15. Random phase approximation: from Giant to Intra-doublet resonances

    International Nuclear Information System (INIS)

    Amusia, M.Ya.

    2004-01-01

    We discuss here the history and current achievements of one of the most powerful approaches of 20th century physics--the random phase approximation (RPA) that permits us to study collective or multiparticle effects in atoms, nuclei, molecules and clusters, as well as in quantum liquids. We concentrate on RPA application to studies of isolated atoms where it permits one to disclose the collective multielectron nature of so-called Giant resonances and predict a number of others, like Interference and Intra-doublet resonances. We present general theory as well as results of concrete calculations for a number of atoms

  16. Random phase approximation: from Giant to Intra-doublet resonances

    Energy Technology Data Exchange (ETDEWEB)

    Amusia, M.Ya. E-mail: amusia@vms.huji.ac.il

    2004-06-01

    We discuss here the history and current achievements of one of the most powerful approaches of 20th century physics--the random phase approximation (RPA) that permits us to study collective or multiparticle effects in atoms, nuclei, molecules and clusters, as well as in quantum liquids. We concentrate on RPA application to studies of isolated atoms where it permits one to disclose the collective multielectron nature of so-called Giant resonances and predict a number of others, like Interference and Intra-doublet resonances. We present general theory as well as results of concrete calculations for a number of atoms.

  17. Finite temperature effects on monopole and dipole excitations

    International Nuclear Information System (INIS)

    Niu, Y F; Paar, N; Vretenar, D; Meng, J

    2011-01-01

    The relativistic random phase approximation based on effective Lagrangian with density dependent meson-nucleon couplings has been extended to finite temperature and employed in studies of multipole excitations within the temperature range T = 1 - 2 MeV. The model calculations showed that isoscalar giant monopole and isovector giant dipole resonances are only slightly modified with temperature, but additional transition strength appears at low energies because of thermal unblocking of single-particle orbitals close to the Fermi level. The analysis of low-lying states shows that isoscalar monopole response in 132 Sn results from single particle transitions, while the isovector dipole strength for 60 Ni, located around 10 MeV, is composed of several single particle transitions, accumulating a small degree of collectivity.

  18. Magnetic resonance imaging of large and giant intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, Kenichi; Saito, Akira; Nakasu, Yoko; Matsuda, Masayuki; Handa, Jyoji [Shiga University of Medical Science, Shiga (Japan); Todo, Giro

    1990-06-01

    Twelve large or giant intracranial aneurysms were studied with magnetic resonance (MR) imaging, and the findings were compared with those from computed tomographic (CT) scanning. Characteristic MR features of such aneurysms are: round, extra-axial mass with hypointensity rim; signal void, paradoxical enhancement, or even-echo rephasing due to blood flow; and laminated, eccentric thrombus with increased signal intensity when fresh, perianeurysmal hemorrhage occurs in the acute or subacute stage after aneurysmal rupture. MR imaging, however, often fails to identify or characterize the area of calcification. For the diagnosis of large or giant intracranial aneurysms, MR imaging is apparently superior to CT scanning in differentiating aneurysms from tumors, delineating the blood flow and intraluminal thrombus, and detecting the exact size of the aneurysm. It may also provide useful information concerning the growth mechanisms of aneurysms with or without thrombus formation. (author).

  19. Isotopic dependence of the giant quadrupole resonance in the stable even-mass molybdenum nuclei

    International Nuclear Information System (INIS)

    Moalem, A.; Gaillard, Y.; Bemolle, A.M.; Buenerd, M.; Chauvin, J.; Duhamel, G.; Lebrun, D.; Martin, P.; Perrin, G.; de Saintignon, P.

    1979-01-01

    Inelastic scattering of 110 MeV 3 He particles is used to probe the quadrupole strength in the even Mo isotopes. The peak position of the giant quadrupole resonance is found to decrease more rapidly than predicted by the A/sup -1/3/ law, a behavior very similar to that exhibited by the photonuclear giant dipole resonance. The width and strength of the giant quadrupole resonance are practically constant in 92 Mo through 100 Mo

  20. Giant resonance of electrical multipole from droplet model

    International Nuclear Information System (INIS)

    Tauhata, L.

    1984-01-01

    The formalism of the electrical multipole resonance developed from the Droplet nuclear model is presented. It combines the approaches of Goldhaber-Teller (GT) and Steinwedel-Jensen (SJ) and it shows the relative contribution of Coulomb, superficial and neutron excess energies. It also discusses the calculation of half-width. The model evaluates correctly the resonance energies as a function of nuclear mass and allows, through the Mixture Index, the prediction of the complementary participation of modes SJ and GT in the giant nuclear resonance. Values of the mixture index, for each multipolarity, reproduce well the form factors obtained from experiments of charged particle inelastic scattering. The formalism presented for the calculation of the half-width gives a macroscopic description of the friction mechanism. The establishment of the macroscopic structure of the Dissipation Function is used as a reference in the comparison of microscopic calculations. (Author) [pt

  1. Form factors and radiation widths of the giant multipole resonances

    International Nuclear Information System (INIS)

    Denisov, V.Yu.

    1990-01-01

    Simple analytic relations for the form factors of inelastic electron scattering in the Born approximation and radiation widths of the isovector and isoscalar giant multipole resonances are derived. The dynamic relationship between the volume and surface density vibrations were taken into account in this calculation. The form factors in the Born approximation were found to be in satisfactory agreement with experimental data in the region of small transferred momenta. The radiation widths of isoscalar multipole resonances increase when the number of nucleons increase as A 1/3 , and for isovector resonances this dependence has the form f(A)A 1/3 , where f(A) is a slowly increasing function of A. Radiation widths well fit the experimental data

  2. Excitation and photon decay of giant resonances excited by intermediate energy heavy ions

    International Nuclear Information System (INIS)

    Bertrand, F.E.; Beene, J.R.

    1987-01-01

    Inelastic scattering of medium energy heavy ions provides very large cross sections and peak-to-continuum ratios for excitation of giant resonances. For energies above about 50 MeV/nucleon, giant resonances are excited primarily through Coulomb excitation, which is indifferent to isospin, thus providing a good probe for the study of isovector giant resonances. The extremely large cross sections available from heavy ion excitation permit the study of rare decay modes of the giant resonances. In particular, recent measurements have been made of the photon decay of giant resonances following excitation by 22 and 84 MeV/nucleon 17 O projectiles. The singles results at 84 MeV/nucleon yield peak cross sections for the isoscalar giant quadrupole resonance and the isovector giant dipole resonance of approximately 0.8 and 3 barns/sr, respectively. Data on the ground state decay of the isoscalar giant quadrupole and isovector giant dipole resonances are presented and compared with calculations. Decays to low-lying excited states are also discussed. Preliminary results from an experiment to isolate the 208 Pb isovector quadrupole resonance using its gamma decay are presented. 22 refs., 19 figs., 1 tab

  3. Monopole heat

    International Nuclear Information System (INIS)

    Turner, M.S.

    1983-01-01

    Upper bounds on the flux of monopoles incident on the Earth with velocity -5 c(10 16 GeV m -1 ) and on the flux of monopoles incident on Jupiter with velocity -3 c(10 16 GeV m -1 ), are derived. Monopoles moving this slowly lose sufficient energy to be stopped, and then catalyse nucleon decay, releasing heat. The limits are obtained by requiring the rate of energy release from nucleon decay to be less than the measured amount of heat flowing out from the surface of the planet. (U.K.)

  4. Monopole Workshop

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Some 90 physicists from 13 countries gathered in October to examine new evidence and theories concerning the magnetic monopole. The venue was Wingspread, the last, but by no means least, of architect Frank Lloyd Wright's marvellous prairie houses, located in Racine, Wisconsin. While many physicists remain sceptical about magnetic monopoles, a growing number are speculating that they may have been made in the first blaze of creation. If found, monopoles would provide a profound clue as to the origin and nature of the universe

  5. Measurement of isovector giant quadrupole resonance in 40Ca

    International Nuclear Information System (INIS)

    Sims, D.A.; Thompson, M.N.; Rassool, R.; Adler, J.O.; Andersson, B.E.; Hansen, K.; Issaksson, L.; Nilsson, B.; Ruijter, H.; Schroeder, B.; Annand, J.R.M.; McGeorge, J.C.; Crawford, G.I.; Miller, G.J.

    1997-01-01

    The 40 Ca(γ,n) reaction was measured using tagged photons in the energy range 25-50 MeV. Neutrons were detected using two 9-element, liquid scintillator, neutron detectors placed at angles of 55 deg and 125 deg at flight path of 3.2 m. The absolute cross section was determined relative to that for D (γ,n)p, which was measured using a heavy water target. The forward/backward asymmetry in the 40 Ca (γ, n) cross section, resulting from E1/E2 interference has been used to locate and parametrize the isovector giant quadrupole resonance (IVQR). 6 refs., 2 figs

  6. The giant resonances in hot nuclei. Linear response calculations

    International Nuclear Information System (INIS)

    Braghin, F.L.; Vautherin, D.; Abada, A.

    1995-01-01

    The isovector response function of hot nuclear matter is calculated using various effective Skyrme interactions. For Skyrme forces with a small effective mass the strength distribution is found to be nearly independent of temperature, and shows little collective effects. In contrast effective forces with an effective mass close to unity produce at zero temperature sizeable collective effects which disappear at temperatures of a few MeV. The relevance of these results for the saturation of the multiplicity of photons emitted by the giant dipole resonance in hot nuclei observed in recent experiments beyond T = 3 MeV is discussed. (authors). 12 refs., 3 figs

  7. Atomic many-body theory of giant resonances

    International Nuclear Information System (INIS)

    Kelly, H.P.; Altun, Z.

    1987-01-01

    In this paper the use of many-body perturbation theory (MBPT) to include effects of electron correlations is discussed. The various physical processes contributing to the broad photoionization cross sections of the rare gases are studied in terms of the relevant many-body diagrams. Use of the random phase approximation with exchange (RPAE) is discussed by Amusia and Cherepkov. Calculations using the relativistic RPAE are reviewed by Johnson. In addition, many-body perturbation theory (MBPT) is used to study resonances which are due to excitation of bound states degenerate with the continuum. Very interesting giant resonance structure can occur when an inner shell electron is excited into a vacant open-shell orbital of the same principal quantum number. A particular example which is studied is the neutral manganese atom 3p 6 3d 5 4s 2 ( 6 S), in which the spins of the five 3d electrons are aligned. A very large resonance occurs in the 3d and 4s cross sections due to 3p → 3d excitation near 51 eV, and calculations of this resonance by MBPT and RPAE are discussed. A second example of this type of resonance occurs in open-shell rare-earth atoms with configurations 4d 10 4f/sup n/5s 2 5p 6 s 2 . Calculations and experimental results will be discussed for the case of europium with a half-filled sub-shell 4f 7 . 71 references, 15 figures

  8. Evaluation of characteristics of some giant multipole resonances within a many-particle approach

    International Nuclear Information System (INIS)

    Steshenko, A.J.

    1994-01-01

    Within a microscopic approach including the many-particle basis of longitudinal-vibration functions (Sp 2 (2,R))-basis) the widths and energies of some gigantic isoscalar monopole and quadrupole resonances in light magic and near-magic nuclei have been calculated. The theoretical results are in agreement with the available experimental data

  9. The Droplet model of the Giant Fipole Resonance

    International Nuclear Information System (INIS)

    Myers, W.D.; Kodama, T.; El-Jaick, L.J.; Hilf, E.R.

    1976-10-01

    The nuclear Giant Dipole Resonance (GDR) energies are calculated using a macroscopic hydronamical model with two new features. The motion is treated as a combination of the usual Goldhaber-Teller (GT) and Steinwedel-Jensen (SJ) modes, and the restoring forces are all calculated using the Droplet Model. The A dependence of the resonance energies is well reproduced without any adjustable parameters, and the measured magnitude of the energies serves to fix the value of the effective mass m* used in the theory. The GDR is found to consist mainly of a GT-type motion with the SJ-mode becoming more important for heavy nuclei. The width P of the GDR is also estimated on the basis of an expression for one-body damping [pt

  10. Role of giant resonance excitation in heavy ion collisions

    International Nuclear Information System (INIS)

    Catara, F.; Chomaz, Ph.

    1987-01-01

    In this paper we discuss several aspects of heavy ion collisions involving collective vibrational modes. In our approach the relative motion is treated in a semiclassical approximation, while the intrinsic degrees of freedom are described microscopically within the RPA. The differences with respect to macroscopic models are analyzed in the appendix. First we present some results on the inelastic scattering cross section and we show that the structures observed experimentally can be explained in terms of multiple excitation of the Giant Quadrupole Resonance. After we calculate an adiabatic polarization potential describing the coupling to the collective vibrational modes and show that it produces a strong enhancement of the subbarrier fusion cross section. This enhancement is found to be enough to reproduce the experimental data for symmetric systems, while for asymmetric reactions the coupling to other degrees of freedom, like transfer, is needed. Finally we report some preliminary results on a dynamical calculation of the real and imaginary parts of the polarization potential. We show that at high incident energies (E/A > 20MeV) the role of the Giant Quadrupole Resonance becomes dominant

  11. The temperature dependence of giant resonances in high-excited nucleus

    International Nuclear Information System (INIS)

    Li Ming; Song Hongqiu

    1991-01-01

    The Hartree-Fock equation and the linear response theory in finite temperature are used to calculate the positions and transition strenghths of the giant resonances of high-excited nucleus Pb 208 . The result shows a downward shift and a broadening of the giant resonance energies as temperatrue increases

  12. Reaction theory for analysis of nuclear giant resonances production and decay processes

    International Nuclear Information System (INIS)

    Foglia, G.A.

    1991-01-01

    The existence of mixing parameters connected to the different decay forms of the giant resonances was theoretically justified, and their energy dependence determined as well using a reaction theory which treats in a consistent manner the giant multipolar resonances formation and their different decay modes. (L.C.J.A.)

  13. Outward Migration of Giant Planets in Orbital Resonance

    Science.gov (United States)

    D'Angelo, G.; Marzari, F.

    2013-05-01

    A pair of giant planets interacting with a gaseous disk may be subject to convergent orbital migration and become locked into a mean motion resonance. If the orbits are close enough, the tidal gaps produced by the planets in the disk may overlap. This represents a necessary condition to activate the outward migration of the pair. However, a number of other conditions must also be realized in order for this mechanism to operate. We have studied how disk properties, such as turbulence viscosity, temperature, surface density gradient, mass, and age, may affect the outcome of the outward migration process. We have also investigated the implications on this mechanism of the planets' gas accretion. If the pair resembles Jupiter and Saturn, the 3:2 orbital resonance may drive them outward until they reach stalling radii for migration, which are within ~10 AU of the star for disks representative of the early proto-solar nebula. However, planet post-formation conditions in the disk indicate that such planets become typically locked in the 1:2 orbital resonance, which does not lead to outward migration. Planet growth via gas accretion tends to alter the planets' mass-ratio and/or the disk accretion rate toward the star, reducing or inhibiting outward migration. Support from NASA Outer Planets Research Program and NASA Origins of Solar Systems Program is gratefully acknowledged.

  14. Charge-exchange giant resonances as probes of nuclear structure

    International Nuclear Information System (INIS)

    Blomgren, J.

    2001-09-01

    Giant resonances populated in charge-exchange reactions can reveal detailed information about nuclear structure properties, in spite of their apparent featurelessness. The (p,n) and (n,p) reactions - as well as their analog reactions - proceed via the same nuclear matrix element as beta decay. Thereby, they are useful for probing electroweak properties in nuclei, especially for those not accessible to beta decay. The nuclear physics aspects of double beta decay might be investigated in double charge-exchange reactions. detailed nuclear structure information, such as the presence of ground-state correlations, can be revealed via identification of 'first-forbidden' transitions. In addition, astrophysics aspects and halo properties of nuclei have been investigated in charge exchange. Finally, these experiments have questioned our knowledge of the absolute strength of the strong interaction

  15. The giant quadrupole resonance in highly excited rotating nuclei

    International Nuclear Information System (INIS)

    Civitarese, O.; Furui, S.; Ploszajczak, M.; Faessler, A.

    1983-01-01

    The giant quadrupole resonance in highly excited, fast rotating nuclei is studied as a function of both the nuclear temperature and the nuclear angular momentum. The photo-absorption cross sections for quadrupole radiation in 156 Dy, 160 Er and 164 Er are evaluated within the linear response theory. The strength functions of the γ-ray spectrum obtained from the decay of highly excited nuclear states by deexcitation of the isoscalar quadrupole mode show a fine structure, which depends on the temperature T, the angular momentum I and the deformation of the nucleus β. The splitting of the modes associated with the signature-conserving and signature-changing components of the quadrupole field is discussed. (orig.)

  16. Phase-space exploration in nuclear giant resonance decay

    International Nuclear Information System (INIS)

    Drozdz, S.; Nishizaki, S.; Wambach, J.; Speth, J.

    1995-01-01

    The rate of phase-space exploration in the decay of isovector and isoscalar giant quadrupole resonances in 40 Ca is analyzed. The study is based on the time dependence of the survival probability and of the spectrum of generalized entropies evaluated in the space of one-particle--one-hole (1p-1h) and 2p-2h states. Three different cases for the level distribution of 2p-2h background states, corresponding to (a) high degeneracy, (b) classically regular motion, and (c) classically chaotic motion, are studied. In the latter case the isovector excitation evolves almost statistically while the isoscalar excitation remains largely localized, even though it penetrates the whole available phase space

  17. The giant resonance and the shape of hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bracco, A; Camera, F; Million, B; Pignanelli, M [Milan Univ. (Italy). Ist. di Fisica; Gaardhoje, J J; Maj, A; Atac, A [Niels Bohr Inst., Copenhagen (Denmark)

    1992-08-01

    The gamma decay of the giant dipole resonance is a sensitive tool for investigating how nuclear shape changes with spin and excitation energy, but the information is coded in a subtle way, inasmuch as the shape and orientation of nuclei at finite temperature display large fluctuations. At the time of the conference, the three systems {sup 109-110}Sn, {sup 161-162}Yb and {sup 165-167}Er had recently been studied on the HECTOR spectrometer. The Sn nuclei are spherical in their ground states, and are expected to become oblate under the stress of rotation. The Yb and Er nuclei are prolate, and are expected to become first spherical, then oblate. While the patterns of the measured angular anisotropies are consistent with this general picture, many questions still remain open. 3 refs., 1 tab., 3 figs.

  18. Photoionization of lanthanum and its ions in the region of the 'giant' resonance

    International Nuclear Information System (INIS)

    Amusia, M.Ya.

    1989-01-01

    The photoionization cross sections of outer and intermediate shells including 4d of La and its ions are calculated in the region of the 'giant' resonance. The prominent effects of both intershell correlational effects and rearrangement are demonstrated. (orig.)

  19. Inelastic scattering of 9Be of 27 MeV/A to giant resonances

    International Nuclear Information System (INIS)

    Lebrun, D.; Buenerd, M.; Bini, M.; Harvey, B.G.; Legrain, R.; Mahoney, J.; Symons, T.J.M.; Van Bibber, K.

    1980-07-01

    Inelastic scattering spectra have been measured with 245 MeV incident energy 9 Be ions, on 208 Pb target. They show large excitation of the 208 Pb giant quadrupole resonance. DWBA calculations are reported and compared with the data

  20. Influence of complex particle emission on properties of giant dipole resonance of hot nuclei

    International Nuclear Information System (INIS)

    Wen Wanxin; Jin Genming

    2003-01-01

    The possible reasons for the discrepancy between calculation results based on the statistical evaporation model and experimental data of giant dipole resonance of very hot nuclei are discussed. Both of simulations with the standard CASCADE code and the code coupling complex particle emission are carried out. It is shown that the complex particle emission affects the properties of giant dipole resonance of very hot nuclei

  1. Spin-flip isovector giant resonances from the 90Zr (n,p) 90Y reaction at 200 MeV

    International Nuclear Information System (INIS)

    Raywood, K.J.; Spicer, B.M.

    1989-01-01

    Doubly differential cross sections of the reaction 90 Zr(n,p) 90 Y have been measured at 200 MeV for excitations up to 38 MeV in the residual nucleus. An overall resolution of 1.3 MeV was achieved. The spectra show qualitative agreement in shape and magnitude with recent RPA calculations; however all of the calculations underestimate the high excitation region of the spectra. A multipole decomposition of the data has been performed using differential cross sections calculated in the DWIA. An estimate of the Gamow-Teller strength in the reaction is given. The isovector spin-flip dipole giant resonance has been identified and there is also an indication of isovector monopole strength. 39 refs., 16 figs., 1 tab

  2. Spectroscopic factors of the alpha decay of isoscalar giant resonances

    International Nuclear Information System (INIS)

    Smirnov, Yu.F.; Chuvil'skij, Yu.M.

    1983-01-01

    A system which enables to connect Ssub(α) spectroscopic factors (SF) for α-decay of the isoscalar giant resonance (GR) states E0 and E2 with SF values for ground and low lying nucleus states has been developed. This method permits to consider initial nucleus GR decay with a transition to the residual nucleus-GR. It is necessary to know only SF for GR decay to the daughter nucleus ground state with the emission of an excited cluster in the common case. The above method is based on properties of infinitesimal operators of Sp(2, R), Sp(6, R) groups and uses SU(3)-symmetry of wave functions of initial nucleus, cluster and residual nucleus, Values of ratios of α-particle SF are presented for 8 Be, HH2C, 16 O, 20 Ne, 24 Mg, 28 Si, 40 Ca, 44 Ti nuclei and Ssub(α) transitions to GR states of residual nucleus for 16 O, 20 Ne and 40 Ca nuclei. Noticeable Ssub(α) values for virtual α-decay of an initial nucleus ground state to residual nucleus GR poins out that α-particle knock out processes may be also accompanied by the final nucleus GR excitation

  3. Studies of the giant resonances in heavy nuclei

    International Nuclear Information System (INIS)

    Cataldi, M.I.C.

    1986-01-01

    Experimental measurements of the eletrodisintegration cross section in 181 Ta, 208 Pb and 209 Bi nuclei are made in the Linear Accelerator of the IFUSP-Brazil. The cross section is obtained by the direct counting of the emitted neutrons, in an electron excitation energy range between 8 to 22 MeV. The experimental data are analysed throught the virtual photon method, with the aim of obtaining the isoscalar and isovectorial electric quadrupole giant resonance (E2GR) intensities, as well as the magnetic dipole intensity. For each studied nucleus the results obtained for the E2GR, isoscalar and isovectorial, are compared with the photodisintegration cross section measured by the Saclay and Livermore laboratories. From this comparison, it is observed that the photodisintegration cross sections are compatibles with the existence of an isovector E2GR, located between 120 to 130 A -1/3 Mev and which exhaust around 100% of the Energy-Weighted Sum rules (EWSR). (L.C.) [pt

  4. Giant quadrupole resonance in 12C, 24Mg, and 27Al observed via deuteron inelastic scattering

    International Nuclear Information System (INIS)

    Chang, C.C.; Didelez, J.P.; Kwiatowski, K.; Wo, J.R.

    1977-06-01

    Giant quadrupole resonance in 12 C, 24 Mg, and 27 Al was studied using 70 MeV deuteron beam. The results clearly show, in all three targets, resonance-like structures peaked at E/sub x/ approximately 63A/sup -1/3/ MeV, with a width of about 10 MeV. The experimental angular distributions for these resonances agree well with the l = 2 DWBA prediction. For 12 C, a binary splitting was observed, and for 24 Mg, there are indications of finer structure in the main giant quadrupole resonance region

  5. Giant Cu 2p Resonances in CuO Valence-Band Photoemission

    NARCIS (Netherlands)

    Tjeng, L.H.; Chen, C.T.; Ghijsen, J.; Rudolf, P.; Sette, F.

    1991-01-01

    We report the observation of a giant resonance in the Cu 2p resonant-photoemission spectra of CuO. The study allows the unambiguous identification of the local Cu 3d8 configuration in the valence-band photoemission spectrum, providing conclusive evidence for the charge-transfer nature of the

  6. Thermal and rotational effect on giant dipole resonances in rotating nuclei at high temperature

    International Nuclear Information System (INIS)

    Sugawara-Tanabe, Kazuko; Tanabe, Kosai.

    1986-01-01

    Microscopic calculations are carried out for the giant dipole resonances excited on the thermal high spin states in 162 Er and 166 Er based on the thermal linear response theory with realistic forces and large single-particle space. The dynamical strength function is compared with the experimental γ-ray absorption cross section. The general trend that the resonance energy decreases and the resonance width increases with increasing angular momentum and temperature is well reproduced by the calculations. (author)

  7. Decay of giant resonance E2 isoscalar in heavy nuclei. Decaimento da ressonancia gigante E2 isoescalar em nucleos pesados

    Energy Technology Data Exchange (ETDEWEB)

    Herdade, S B [Sao Paulo Univ., SP (Brazil). Inst. de Fisica

    1980-01-01

    In this work, it is made a study of the giant resonance E2 isoscalar, in heavy nuclei. Fission probabilities for this resonance were determined by various authors, in different experiments, for {sup 238}U. (A.C.A.S.).

  8. Giant dipole resonances in hot nuclear matter in the model of self-relaxing mean field

    International Nuclear Information System (INIS)

    Okolowicz, J.; Ploszajczak, M.; Drozdz, S.; Caurier, E.

    1989-01-01

    The extended time-dependent Hartree-Fock approach is applied for the description of the isovector giant dipole resonance in 40 Ca at finite temperatures. The thermalization process is described using the relaxation-time ansatz for the collision integral. Strong inhibition of the giant-dipole-resonance γ-decay is found due to the fast vaporization of the nuclear surface for thermal excitation energies above E * /A ≅ 4.5 MeV. This pre-equilibrium emission of particles in the vapor phase is associated with the radial expansion of nucleus and with the vanishing particle binding energies mainly for protons. (orig.)

  9. Sum rule approach to the study of statistical decay properties of nuclear giant resonances

    International Nuclear Information System (INIS)

    Adhikari, S.K.; Hussein, M.S.

    1987-03-01

    Corrections to the well-known statistical sum rule that relates the summed transmission coefficients on the one hand and 2πΓ C.N. .ρ C.N. On the other, in the context of the statistical decay properties of nuclear giant resonances, are discussed. These corrections arise both from pre-equilibrium processes as well as from the giant resonance itself. It is shown that the compound nucleus average width is reduced as a result of these corrections. (Author) [pt

  10. Dirac monopole without strings: monopole harmonics

    International Nuclear Information System (INIS)

    Wu, T.T.; Yang, C.N.

    1983-01-01

    Using the ideas developed in a previous paper which are borrowed from the mathematics of fiber bundles, it is shown that the wave function psi of a particle of charge Ze around a Dirac monopole of strength g should be regarded as a section. The section is without discontinuities. Thus the monopole does not possess strings of singularities in the field around it. The eigensections of the angular momentum operators are monopole harmonics which are explicitly exhibited. 7 references, 2 figures, 1 table

  11. Spin-flip measurements in the proton inelastic scattering on 12C and giant resonance effects

    International Nuclear Information System (INIS)

    De Leo, R.; D'Erasmo, G.; Ferrero, F.; Pantaleo, A.; Pignanelli, M.

    1975-01-01

    Differential cross sections and spin-flip probabilities (SFP) for the inelastic scattering of protons, exciting the 2 + state at 4.43 MeV in 12 C, have been measured at several incident energies between 15.9 and 37.6 MeV. The changes in the shape of the SFP angular distributions are rather limited, while the absolute values show a pronounced increase, resonant like, in two energy regions centered at about 20 and 29 MeV. The second resonance reproduces very closely the energy dependence of the E2 giant quadrupole strength found in a previous experiment. The resonance at 20 MeV should correspond to a substructure of the E1 giant dipole resonance. (Auth.)

  12. Search for magnetic dipole strength and giant spin-flip resonances in heavy nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Horen, D. J. [Oak Ridge National Lab., TN (USA); Ikegami, H.; Muraoka, M. [eds.; Osaka Univ., Suita (Japan). Research Center for Nuclear Physics

    1980-01-01

    A description is given of the use of high resolution (n, n) scattering and the (p, n) reaction as tools to investigate highly excited states with emphasis on information pertaining to magnetic dipole strength and giant spin-flip resonances in heavy nuclei. It is shown how the ability to uniquely determine the spins and parities of resonances observed in neutron scattering has been instrumental to an understanding of the distribution of M1 strength in sup(207,208)Pb. Some recent results of (p, n) studies with intermediate energy protons are discussed. Energy systematics of the giant Gamow-Teller (GT) resonance as well as a new ..delta..l = 1, ..delta..S = 1 resonance with J sup(..pi..) = (1,2)/sup -/ are presented. It is shown how the (p, n) reaction might be useful to locate M1 strength in heavy nuclei.

  13. Study of the giant multipole resonances, especially the isoscalar giant E2 resonance in 208Pb by inelastic electron scattering with medium and high energy resolution

    International Nuclear Information System (INIS)

    Kuehner, E.G.F.

    1982-01-01

    In the nucleus 208 Pb giant multipole resonances were looked for by inelastic electron scattering up to excitation energies of Esub(x) = 35 MeV. Twelve spectra were taken up at incident energies of Esub(o) = 45-65 MeV under scattering angles from upsilon = 93 0 to 165 0 . The cross sections extracted from this were analyzed by means of DWBA calculations using RPA amplitudes from a model with separable residual interaction. Basing on this analysis for the first time it could be shown that the maximum in the electron scattering cross section at Esub(x) approx.= 14 MeV can be consistently described as a superposition of the Jsup(π) = 1 - , ΔT = 1 with a Jsup(π) = 0 + , ΔT = 0 giant resonance. Furthermore the spectra under backward scattering angles indicate the existence of a magnetic excitation at Esub(x) approx.= 15 MeV which is interpreted as Jsup(π) = 3 + giant resonance. Besides under forwards angles a further weak excitation appears at Esub(x) approx.= 14.6 MeV which is very well compatible with Jsup(π) = 2 + . At Esub(x) = 17.5 MeV a Jsup(π) = 3 - resonance was found which recently is also observed in (α,α') scattering experiments and therefore gets a ΔT = 0 assignment. A further resonance at Esub(x) approx.= 21 MeV has also Jsup(π) = 3 - character but has partly to be assigned to a Jsup(π) = 1 - , ΔT = 0 excitation. At Esub(x) = 23.8 MeV a Jsup(π) = 2 + excitation was found which gels because of model predictions a ΔT = 1 assignment. (orig./HSI) [de

  14. Study of the giant multipole resonances especially of the isoscalar giant E2 resonance in 208Pb by medium and high energy resolution inelastic electron scattering

    International Nuclear Information System (INIS)

    Kuehner, G.

    1982-01-01

    In the nucleus 208 Pb giant multipole resonances up to excitation energies of Esub(x) = 35 MeV were looked for by medium resolution inelastic electron scattering. Twelve spectra were taken up at incident energies of E 0 = 45-65 MeV under scattering angles from upsilon = 93 0 to 165 0 . The cross sections extracted from this were analyzed by means of DWBA calculations using RPA amplitudes from a model with separable residual interaction. On the base of this analysis for the first time it could be shown that the maximum in the electron scattering cross section at Esub(x) approx.= 14 MeV can be consistently described as superposition of the Jsup(π) = 1 - , ΔT = 1 with a Jsup(π) = 0 + , ΔT = 0 giant resonance. Furthermore the spectra under backward scattering angles indicate the existence of a magnetic excitation at Esub(x) approx.= 15 MeV which is interpreted as Jsup(π) = 3 + giant resonance. Besides under forward angles a further weak excitation at Esub(x) approx.= 14.6 MeV appears which is very well compatible with Jsup(π) = 2 + . At Esub(x) = 17.5 MeV a Jsup(π) = 3 - resonance was found which recently is observed also in (α, α') experiments and therefore gets a ΔT = 0 assignment. A further resonance at Esub(x) approx.= 21 MeV has also a Jsup(π) = 3 - character but has to be partly assigned to a Jsup(π) = 1 - , ΔT = 0 excitation. At Esub(x) = 23.8 MeV a Jsup(π) = 2 + excitation was found which gets because of model predictions a ΔT = 1 assignment. (orig./HSI) [de

  15. Double giant resonances in time-dependent relativistic mean-field theory

    International Nuclear Information System (INIS)

    Ring, P.; Podobnik, B.

    1996-01-01

    Collective vibrations in spherical nuclei are described in the framework of time-dependent relativistic mean-field theory (RMFT). Isoscalar quadrupole and isovector dipole oscillations that correspond to giant resonances are studied, and possible excitations of higher modes are investigated. We find evidence for modes which can be interpreted as double resonances. In a quantized RMFT they correspond to two-phonon states. (orig.)

  16. Electromagnetic transitions between giant resonances within a continuum-RPA approach

    NARCIS (Netherlands)

    Rodin, VA; Dieperink, AEL

    2002-01-01

    A general continuum-RPA approach is developed to describe electromagnetic transitions between giant resonances. Using a diagrammatic representation for the three-point Green's function, an expression for the transition amplitude is derived which allows one to incorporate effects of mixing of single

  17. Can we learn about the spin-flip giant dipole resonances with pions

    International Nuclear Information System (INIS)

    Baer, H.W.

    1982-01-01

    Data and calculations for the 40 Ca(π+-,π 0 ) reactions at 164 MeV are shown which indicate that pion scattering possesses a unique signature for separately identifying the 1 - and 2 - spin-isospin components of the giant dipole resonance

  18. Coupling effects of giant resonances on the elastic and inelastic scattering of fast neutrons

    International Nuclear Information System (INIS)

    Delaroche, J.P.; Tornow, W.

    1983-01-01

    While the inelastic scattering of high energy hadrons is commonly used for the study of giant resonances in nuclei, it is just recently that one has thought to take into account these states in the analysis of proton scattering at low incident energies (E 0 and S 1 . (Auth.)

  19. The temperature dependence of the width of the giant-dipole resonance

    International Nuclear Information System (INIS)

    Ormand, W.E.; Bortignon, P.F.; Broglia, R.A.

    1996-01-01

    The giant-dipole resonance (GDR) in 120 Sn and 208 Pb is studied as a function of excitation energy, angular momentum, and intrinsic width within the context of the adiabatic model. Theoretical evaluations of the full-width-at-half-maximum (FWHM) for the GDR strength function are compared with recent experimental data and are found to be in good agreement. (orig.)

  20. Data systematics and semidirect decay probability of the giant dipole resonance

    International Nuclear Information System (INIS)

    Ishkhanov, B.S.; Kapitonov, I.M.; Tutyn', I.A.

    1998-01-01

    Information on probability of semidirect decay of giant dipole resonance of nuclei of sd- and fp-shells (A = 16-58) is elaborated on the base of the recent (γ, χγ ' ) experimental results. The shell effect in A-dependence of this probability is discovered

  1. Isovector giant dipole resonance in hot rotating light nuclei in the calcium region

    International Nuclear Information System (INIS)

    Shanmugam, G.; Thiagasundaram, M.

    1989-01-01

    The isovector giant dipole resonances in hot rotating light nuclei in the calcium region are studied using a rotating anisotropic harmonic oscillator potential and a separable dipole-dipole residual interaction. The influence of temperature on the isovector giant dipole resonance is assumed to occur through the change of deformation of the average field only. Calculations are performed for the three nuclei /sup 40,42/Ca and /sup 46/Ti which have spherical, oblate, and prolate ground states, respectively, to see how their shape transitions at higher excited states affect the isovector giant resonance frequencies built on them. It is seen that, while the width fluctuations present at T = 0 vanish at T = 0.5 MeV in /sup 40,42/Ca, they persist up to T = 1.5 MeV in the case of /sup 46/Ti. This behavior brings out the role of temperature on shell effects which in turn affects the isovector giant dipole resonance widths

  2. The photoionization of atomic Eu in the vicinity of its giant resonance

    International Nuclear Information System (INIS)

    Amusia, M.Ya.

    1989-01-01

    It is demonstrated that the partial photoionization cross sections of outer subshells of atomic Eu in the giant resonance region are determined by the action of the 4d-electron excitations. The cross section for photoionization of the semifilled 4f 7 subshell is also entirely dominated by the interaction with 4d 10 electrons. (orig.)

  3. Collective doorways and statistical doorways: The decay properties of giant multipole resonances

    International Nuclear Information System (INIS)

    Dias, H.; Hussein, M.S.; Adhikari, S.K.

    1985-01-01

    A theoretical framework for the description of the decay of giant multipole resonances is developed. It is shown that the statistical decay of the GMR is not necessarily described by the Hauser-Feschbach theory owing to the existence of a mixing parameter. The contribution of pre-equilibrium emission to the GMR decay is also discussed. (Author) [pt

  4. Direct and statistical gamma decay of the giant quadrupole resonance of 208Pb

    International Nuclear Information System (INIS)

    Dias, H.; Hussein, M.S.; Carlson, B.V.; Merchant, A.C.

    1986-03-01

    The gamma decay of the giant quadrupole resonance of 208 Pb is discussed. The relative contribution of the decay via the compound nucleus is calculated from the statistical theory. It is found that the compound decay is as important as the direct decay. (Author) [pt

  5. Neutron-skin thickness from the study of the anti-analog giant dipole resonance

    NARCIS (Netherlands)

    Krasznahorkay, A.; Stuhl, L.; Csatlós, M.; Algora, A.; Gulyás, J.; Timár, J.; Paar, N.; Vretenar, D.; Boretzky, K.; Heil, M.; Litvinov, Yu A.; Rossi, D.; Scheidenberger, C.; Simon, H.; Weick, H.; Bracco, A.; Brambilla, S.; Blasi, N.; Camera, F.; Giaz, A.; Million, B.; Pellegri, L.; Riboldi, S.; Wieland, O.; Altstadt, S.; Fonseca, M.; Glorius, J.; Göbel, K.; Heftrich, T.; Koloczek, A.; Kräckmann, S.; Langer, C.; Plag, R.; Pohl, M.; Rastrepina, G.; Reifarth, R.; Schmidt, S.; Sonnabend, K.; Weigand, M.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Rigollet, C.; Bagchi, S.; Najafi, M. A.; Aumann, T.; Atar, L.; Heine, M.; Holl, M.; Movsesyan, A.; Schrock, P.; Volkov, V.; Wamers, F.; Fiori, E.; Löher, B.; Marganiec, J.; Savran, D.; Johansson, H. T.; Fernández, P. Diaz; Garg, U.; Balabanski, D. L.

    2012-01-01

    The gamma-decay of the anti-analog of the giant dipole resonance (AGDR) has been measured to the isobaric analog state excited in the p(124Sn,n) reaction at a beam energy of 600 MeV/nucleon. The energy of the transition was also calculated with state-of-the-art self-consistent random-phase

  6. A collective model description of the low lying and giant dipole resonant properties of 40424446Ca

    International Nuclear Information System (INIS)

    Weise, J.I.

    1982-01-01

    The low-lying and giant dipole resonant properties of the even-even calcium isotopes are calculated within the framework of the Gneuss-Greiner model and compared with the experimental data. In the low energy region, comparison is also made with the predictions of a coexistence model

  7. Monopole searches at ISABELLE

    International Nuclear Information System (INIS)

    Giacomelli, G.; Thorndike, A.

    1975-01-01

    A discussion is given which supports the continuance of the search for magnetic monopoles at ISABELLE, based on the following assumptions: (1) by 1982 monopoles have not been found; (2) this indicates that, if they exist, they are very massive; (3) other monopole properties are as they are usually assumed to be. An experiment to search for dense tracks is described, an outline is given of a monopole collector for induced current detection, and some discussion is given of the multigamma approach

  8. Gravitationally coupled electroweak monopole

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Y.M., E-mail: ymcho7@konkuk.ac.kr [Administration Building 310-4, Konkuk University, Seoul 143-701 (Korea, Republic of); School of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Kimm, Kyoungtae [Faculty of Liberal Education, Seoul National University, Seoul 151-747 (Korea, Republic of); Yoon, J.H. [Department of Physics, College of Natural Sciences, Konkuk University, Seoul 143-701 (Korea, Republic of)

    2016-10-10

    We present a family of gravitationally coupled electroweak monopole solutions in Einstein–Weinberg–Salam theory. Our result confirms the existence of globally regular gravitating electroweak monopole which changes to the magnetically charged black hole as the Higgs vacuum value approaches to the Planck scale. Moreover, our solutions could provide a more accurate description of the monopole stars and magnetically charged black holes.

  9. Giant magnetic modulation of a planar, hybrid metamolecule resonance

    International Nuclear Information System (INIS)

    Gregory, Simon A; Stenning, Gavin B G; Bowden, Graham J; De Groot, Peter A J; Zheludev, Nikolay I

    2014-01-01

    Coupling magnetic elements to metamaterial structures creates hybrid metamolecules with new opportunities. Here we report on the magnetic control of a metamolecule resonance, by utilizing the interaction between a single split ring resonator (SRR) and a magnetic thin film of permalloy. To suppress eddy current shielding, the permalloy films are patterned into arrays of 30–500 μm diameter discs. Strong hybridized resonances were observed at the anticrossing between the split ring resonance and the ferromagnetic resonance (FMR) of the permalloy. In particular, it is possible to achieve 40 dB modulation of the electric (symmetric) mode of the SRR on sweeping the applied magnetic field through the SRR/FMR anticrossing. The results open the way to the design of planar metamaterials, with potential applications in nonlinear metamaterials, tunable metamaterials and spintronics. (papers)

  10. (e,e'f) coincidence experiments for fission decay of giant resonances in 235,238U

    International Nuclear Information System (INIS)

    Weber, T.; Heil, R.D.; Kneissl, U.; Pecho, W.; Wilke, W.; Emrich, H.J.; Kihm, T.; Knoepfle, K.T.

    1988-01-01

    Extending previous work on 238 U, 235 U(e,e'f) coincidence data were taken at 4 momentum transfers yielding both E1, E2/E0 and E3 form factors and the respective multipole strength distributions in the giant resonance region of 238 U (4 x x /Γ a is obtained as a function of excitation energy for separated multipoles. The giant E2 resonance exhibits an increased symmetric fission contribution compared to E1 and E3 resonances. (orig.)

  11. NATO Advanced Study Institute on Giant Resonances in Atoms, Molecules, and Solids

    CERN Document Server

    Esteva, J; Karnatak, R

    1987-01-01

    Often, a new area of science grows at the confines between recognised subject divisions, drawing upon techniques and intellectual perspectives from a diversity of fields. Such growth can remain unnoticed at first, until a characteristic fami ly of effects, described by appropriate key words, has developed, at which point a distinct subject is born. Such is very much the case with atomic 'giant resonances'. For a start, their name itself was borrowed from the field of nuclear collective resonances. The energy range in which they occur, at the juncture of the extreme UV and the soft X-rays, remains to this day a meeting point of two different experimental techniques: the grating and the crystal spectrometer. The impetus of synchrotron spectroscopy also played a large part in developing novel methods, described by many acronyms, which are used to study 'giant resonances' today. Finally, although we have described them as 'atomic' to differentiate them from their counterparts in Nuclear Physics, their occurrence ...

  12. Magnetic monopole search experiments

    International Nuclear Information System (INIS)

    Stone, J.L.

    1986-01-01

    Experimental searches for the elusive magnetic monopole have extended over 50 years -- ever since Dirac showed that the existence of isolated magnetic charges could account for the observation of quantized electric charge. Early searches for Dirac's monopole were hampered since there was no indication of the expected monopole mass, velocity, or origin in the theory. Consequently, numerous experiments searched more or less blindly for relativistic low mass monopoles in the cosmic rays and in particle collisions at high energy accelerators. In this paper, the author reviews briefly the monopole properties which are relevant for their detection and summarize current experimental efforts using induction, ionization/excitation, and catalysis techniques

  13. Are there nuclear structure effects on the isoscalar giant monopole resonance and nuclear incompressibility near A ∼ 90?

    International Nuclear Information System (INIS)

    Gupta, Y.K.

    2016-01-01

    Nuclear structure effects have not been observed in any of the investigations of ISGMR going back to its first identification in the late 1970's and, indeed, would be contrary to the standard hydrodynamical picture associated with this mode of collective oscillation. In this paper, the compressional modes in the 90,92 Zr and 92 Mo nuclei from inelastic α-scattering measurements, free from instrumental background, at an energy of 385 MeV are reported on

  14. Angular correlation experiments for the study of giant multipole resonances and currents of the second kind in atomic nuclei

    International Nuclear Information System (INIS)

    1986-03-01

    The project dealt with angular correlation experiments for the study of giant multipole resonances and currents of the second kind in atomic nuclei. Both partial projects were worked in the period of the report. (orig.) [de

  15. Damping of isovector giant dipole resonances in hot even-even spherical nuclei

    International Nuclear Information System (INIS)

    Dang, N.D.

    1989-01-01

    An approach based on the finite temperature quasiparticle phonon nuclear model (FT-QPNM) with the couplings to (2p2h) states at finite temperature taken into account is suggested for calculations of the damping of giant multipole resonances in hot even-even spherical nuclei. The strength functions for the isovector giant dipole resonance (IV-GDR) are calculated in 58 Ni and 90 Zr for a range of temperatures up to 3 MeV. The results show that the contribution of the interactions with (2p2h) configurations to the IV-GDR spreading width changes weakly with varying temperature. The IV-GDR centroid energy decreases slightly with increasing temperature. The nonvanishing superfluid pairing gap due to thermal fluctuations is included. (orig.)

  16. Multipole giant resonances of 12C nucleus electro excitation in intermediate coupling model

    International Nuclear Information System (INIS)

    Goncharova, N.G.; Zhivopistsev, F.A.

    1977-01-01

    Multipole giant resonances in 12 C electroexcitation are considered using the shell model with coupling. Cross sections are calculated for the states of 1 - , 2 - , 3 - , 4 - , at T=1. The distributions of the transverse form factor at transferred momenta equal to q approximately 0.75, 1.04, 1.22 and 1.56 Fm -1 and the longitudinal form factor for q = 0.75, 1.04, 1.56 Fm -1 are presented. For the excitation energies in the range from 18 to 28 MeV positive-parity states have a small contribution in the cross section. The distribution of the total form factor in the excitation energies is given. It is concluded that the multipole giant resonances of anomalous parity levels calculated within the interatomic-coupling shell model show a satisfactorily close agreement with the behavior of experimental form factors in the excitation energy range from 18 to 28 MeV

  17. Dramatic distortion of the 4d giant resonance by the C{sub 60} fullerene shell

    Energy Technology Data Exchange (ETDEWEB)

    Amusia, M Ya [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Baltenkov, A S [Arifov Institute of Electronics, Akademgorodok, 700125 Tashkent (Uzbekistan); Chernysheva, L V [A F Ioffe Physical-Technical Institute, St Petersburg 194021 (Russian Federation); Felfli, Z [Department of Physics and Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, GA 30314 (United States); Msezane, A Z [Department of Physics and Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, GA 30314 (United States)

    2005-05-28

    The photoionization cross section for the endohedral Xe at C{sub 60} atom is investigated within the framework of representing the C{sub 60} by a delta-type potential. Results demonstrate that in Xe at C{sub 60}, the 4d giant resonance is distorted significantly when compared with that of the isolated Xe atom. The reflection of the photoelectron waves by the C{sub 60} causes strong oscillations in the photoionization cross section resulting in the replacement of the Xe 4d giant resonance by four prominent peaks. The approximation of C{sub 60} by an infinitely thin real potential preserves reasonably well the sum rule for the 4d electrons but modifies the dipole polarizability of the 4d shell. (letter to the editor)

  18. The giant-dipole-resonance effect in coulomb excitation of 10B

    International Nuclear Information System (INIS)

    Vermeer, W.J.; Zabel, T.H.; Esat, M.T.; Kuehner, J.A.; Spear, R.H.; Baxter, A.M.

    1982-04-01

    Coulomb excitation of the 0.718-MeV, Jsup(π) = 1 + , first excited state of 10 B has been studied using projectile excitation by 208 Pb and observing the backward scattered particles. The results give a clear indication of the virtual excitation of the giant dipole resonance as a second-order effect. The observed magnitude is consistent with the usual hydrodynamic model estimate and with a recent shell-model calculation

  19. Decay of giant resonances states in radiative pion capture by 1p shell nuclei

    International Nuclear Information System (INIS)

    Dogotar, G.E.

    1978-01-01

    The decay of the giant resonance states excited in tthe radiative pion capture on the 9 Be, 11 B, 13 C and 14 N nuclei is considered in the shell model with intermediate coupling. It is shown that the excited states in the daughter nuclei (A-1, Z-1) are mainly populated by intermediate states with spin by two units larger than the spin of the target nuclei. Selected coincidence experiments are proposed

  20. Geometry of hyperbolic monopoles

    International Nuclear Information System (INIS)

    Nash, C.

    1986-01-01

    The hyperbolic monopoles of Atiyah [M. F. Atiyah, Commun. Math. Phys. 93, 471 (1984); ''Magnetic monopoles in hyperbolic space,'' in Proceedings of the International Colloquium on Vector Bundles (Tata Institute, Bombay, 1984)] and Chakrabarti [A. Chakrabarti, J. Math. Phys. 27, 340 (1986)] are introduced and their geometric properties and relations to instantons and ordinary monopoles clarified. A key tool is the use of the ball model of hyperbolic space to construct and examine solutions

  1. Photoexcitation by gamma-ray scattering near threshold and giant dipole resonance

    International Nuclear Information System (INIS)

    Lakosi, L.; Safar, J.; Veres, A.; Sekine, T.; Kaji, H.; Yoshihara, K.

    1993-01-01

    Photoexcitation of 4.5 h half-life 115m In and 56 min half-life 103m Rh isomers by inelastic gamma-ray scattering near threshold and in the giant dipole resonance region has been reviewed. In disagreement with earlier experimental results available in the literature, but in good agreement with our experiments published recently, present calculations indicate that above the photoneutron emission threshold the isomer excitation drops abruptly and remains orders of magnitude smaller than at the threshold, even around resonance maximum. (author)

  2. Semiclassical approach to giant resonances of rotating nuclei

    International Nuclear Information System (INIS)

    Winter, J.

    1983-01-01

    Quadrupole and isovector dipole resonances of rotating nuclei are investigated in the frame-work of Vlasov equations transformed to a rotating system of reference, which are based on the time-dependent Hartree-method for schematic forces. The parameter free model of the self-consistent vibrating harmonic oscillator potential for the quadrupole mode is extended to a coupling to rotation, which also includes large-amplitude behaviour. A generalization to an exactly solvable two-liquid model describing the isovector mode is established; for rotating nuclei Hilton's explicit result for the eigenfrequencies is obtained. The advantage of using the concept of the classical kinetic momentum in a rotating system also in quantum-mechanical descriptions is demonstrated. It completes the standard transformation of density matrices by a time-odd part realized in a phase-factor and permits a more direct interpretation of rotation effects in terms of the classical forces of inertia. (author)

  3. Monopole Black Hole Skyrmions

    OpenAIRE

    Moss, Ian G; Shiiki, N; Winstanley, E

    2000-01-01

    Charged black hole solutions with pion hair are discussed. These can be\\ud used to study monopole black hole catalysis of proton decay.\\ud There also exist\\ud multi-black hole skyrmion solutions with BPS monopole behaviour.

  4. Monopole catalysis: an overview

    International Nuclear Information System (INIS)

    Dawson, S.

    1983-11-01

    A summary of the talks presented in the topological workshop on monopole catalysis at this conference is given. We place special emphasis on the conservation laws which determine the allowed monopole-fermion interactions and on catalysis as a probe of the structure of a grand unified theory. 11 references

  5. Gauge theories and monopoles

    International Nuclear Information System (INIS)

    Cabibbo, N.

    1983-01-01

    This chapter attempts to present some of the fundamental geometrical ideas at the basis of gauge theories. Describes Dirac Monopoles and discusses those ideas that are not usually found in more ''utilitarian'' presentations which concentrate on QCD or on the Glashow-Salam-Weinberg model. This topic was chosen because of the announcement of the possible detection of a Dirac monopole. The existence of monopoles depends on topological features of gauge theories (i.e., on global properties of field configurations which are unique to gauge theories). Discusses global symmetry-local symmetry; the connection; path dependence and the gauge fields; topology and monopoles; the case of SU(3) x U(1); and the 't Hooft-Polyakov monopole

  6. Two-phonon giant resonances in 136Xe, 208Pb, and 238U

    International Nuclear Information System (INIS)

    Boretzky, K.; Gruenschloss, A.; Ilievski, S.; Adrich, P.; Aumann, T.; Bertulani, C.A.; Cub, J.; Dostal, W.; Eberlein, B.; Elze, T.W.; Emling, H.; Fallot, M.; Holeczek, J.; Holzmann, R.; Kozhuharov, C.; Kratz, J.V.; Kulessa, R.; Leifels, Y.; Leistenschneider, A.; Lubkiewicz, E.; Mordechai, S.; Ohtsuki, T.; Reiter, P.; Simon, H.; Stelzer, K.; Stroth, J.; Suemmerer, K.; Surowiec, A.; Wajda, E.; Walus, W.

    2003-07-01

    The excitation of the double-phonon giant dipole resonance was observed in heavy projectile nuclei impinging on targets of high nuclear charge with energies of 500-700 MeV/nucleon. New experimental data are presented for 136 Xe and 238 U together with further analysis of earlier data on 208 Pb. Differential cross sections dσ/dE * and dσ/dθ for electromagnetic excitations were deduced. Depending on the isotope, cross sections appear to be enhanced in comparison to those expected from a purely harmonic nuclear dipole response. The cumulative effect of excitations of two-phonon states composed of one dipole and one quadrupole phonon, of predicted anharmoniticies in the double-phonon dipole response, and of damping of the dipole resonance during the collision may account for the discrepancy. In addition, decay properties of two-phonon resonances were studied and compared to that of a statistical decay. (orig.)

  7. Giant resonance phenomena in the electron impact ionization of heavy atoms and ions

    International Nuclear Information System (INIS)

    Younger, S.M.

    1986-01-01

    Heavy atoms and ions offer an interesting opportunity to study atomic physics in a region where the atomic structure is dominated by the interelectronic interactions. One illustration of this is the profound term dependence of atomic orbitals for certain configurations of heavy atoms and ions. The appearance of giant scattering resonances in the cross sections for ionization of heavy atoms by electron impact is a manifestation of resonance behavior. Such resonant structures arise from the double well nature of the scattering potential and have recently been identified in the cross sections for the electron impact ionization of several xenon-like ions. The results of calculations showing effects for a variety of other ions are summarized. 7 refs., 4 figs

  8. Survey of the (3He,t) reaction: Excitation of the isobaric analog of the giant dipole resonance

    International Nuclear Information System (INIS)

    Tabor, S.L.; Chang, C.C.; Collins, M.T.; Wagner, G.J.; Wu, J.R.; Halderson, D.W.; Petrovich, F.

    1982-01-01

    The ( 3 He,t) reaction at 130 and 170 MeV has been investigated on targets of 12 C, 16 O, 27 Al, 28 Si, 40 Ca, 46 Ti, and 90 Zr. Data for the ( 3 He, 3 He') reaction were measured simultaneously for reference purposes. Structure is observed in the spectra from the ( 3 He, 3 He') and ( 3 He,t) reaction at the expected positions of the giant quadrupole resonance and the isobaric analog of the giant dipole resonance, respectively. An angular distribution was measured for the suspected giant dipole resonance structure in the 40 Ca( 3 He,t) 40 Sc reaction at 130 MeV. The data are reasonably described by a collective model calculation based on the Goldhaber-Teller model for the giant dipole resonance. Several other strong peaks at excitation energies below the giant dipole resonance are observed in the ( 3 He,t) spectra. Most notable of these are the ones at the expected positions for analogs of well known 1 + states and 1hω stretched states in the targets

  9. Decay of the giant quadrupoles resonance and higher excitation states in 40Ca

    International Nuclear Information System (INIS)

    Alamanos, N.; Fernandez, B.; Gillibert, A.

    1991-01-01

    Light charged particles have been measured in coincidence with inelastically scattered fragments from the 40 Ca + 40 Ca reaction at 50 MeV/N. Such a measurement allows to unravel the different reaction mechanisms contributing to the inelastic spectrum: pick-up break-up reactions, knock out and inelastic excitations. The giant quadrupole resonance in 40 Ca is shown to present a 30% non statistical decay branch. A prominent structure at 34 MeV is attributed to target excitation, the decay of this structure is studied

  10. Atlas of giant dipole resonances. Parameters and graphs of photonuclear reaction cross sections

    International Nuclear Information System (INIS)

    Varlamov, A.V.; Varlamov, V.V.; Rudenko, D.S.; Stepanov, M.E.

    1999-01-01

    Parameters of giant dipole resonances (GDR) observed in photonuclear reaction cross sections using various beams of incident photons are presented. Data, given for 200 stable isotopes from 2 H to 243 Am including their natural compositions, were collected from papers published over the years 1951-1996. GDR parameters, such as energy positions, amplitudes and widths, are included into the table and organized by element, isotope and reaction. Graphs of the majority of the photonuclear reaction cross sections, included in the international nuclear data library EXFOR by the end of 1998, are presented. The graphs are provided for 182 stable isotopes and natural compositions. (author)

  11. Study of the giant Gamow-Teller resonance in nuclear beta-decay

    International Nuclear Information System (INIS)

    Dicklage, R.D. von; Hansen, P.G.

    1984-01-01

    A strong effort has been devoted to the development of new target-ion-source systems at ISOLDE which would give higher yields of proton-rich nuclei. The first break-trough has been obtained for the element argon where one recently was able to produce about three orders of magnitude higher yields than in the first experiments. This makes it possible to perform experiments, involving β-delayed protons and gamma-rays, which may give information about the giant Gamow-Teller resonance. This paper gives a report on the status of these experiments

  12. Correlated ground state and E2 giant resonance built on it

    International Nuclear Information System (INIS)

    Tohyama, Mitsuru

    1995-01-01

    Taking 16 O as an example of realistic nuclei, we demonstrate that a correlated ground state can be obtained as a long time solution of a time-dependent density-matrix formalism (TDDM) when the residual interaction is adiabatically treated. We also study in TDDM the E2 giant resonance of 16 O built on the correlated ground state and compare it with that built on the Hartree-Fock ground state. It is found that a spurious mixing of low frequency components seen in the latter is eliminated by using the correlated ground state. (author)

  13. A study of the giant dipole resonance in doubly even tellurium and cerium isotopes

    International Nuclear Information System (INIS)

    Lepretre, A.; Beil, H.; Bergere, R.; Carlos, P.; Fagot, J.; Miniac, A. de; Veyssiere, A.

    1976-01-01

    The partial photoneutron cross sections [sigma(γ,n)+sigma(γ,pn)] and sigma(γ,2n) of 124 Te, 126 Te, 128 Te, 130 Te and 140 Ce, 142 Ce were measured in the giant dipole resonance region by means of the monochromatic photon beam installation at SACLAY. Absolute total photoneutron cross sections, Lorentz line parameters and integrated cross sections are evaluated. The experimental behaviour of the GDR for the above nuclei and in particular its spreading, is then tentatively interpreted in terms of the improved dynamic collective model using the concept of potential energy surfaces. (Auth.)

  14. Nonperturbative study of the damping of giant resonances in hot nuclei

    International Nuclear Information System (INIS)

    De Blasio, F.V.; Cassing, W.; Tohyama, M.; Bortignon, P.F.; Broglia, R.A.

    1992-01-01

    The damping of dipole and quadrupole motion in 16 O and 40 Ca at zero and finite temperature is studied including particle-particle and particle-hole interactions to all orders of perturbation. We find that the dipole dynamics in these light nuclei is well described in terms of mean-field theory (time-dependent Hartree-Fock), while the quadrupole motion is strongly damped through the coupling to more complicated configurations. Both the centroid and the damping width of the quadrupole and dipole giant resonances show a clear stability with temperature as a consequence of the weakening of the interaction, which contrasts with the increase of the phase space

  15. Chaos-driven decay of nuclear giant resonances: Quantum route to self-organization

    International Nuclear Information System (INIS)

    Drozdz, S.; Nishizaki, S.; Wambach, J.

    1994-01-01

    The influence of background states with increasing level of complexity on the strength distribution of the isoscalar and isovector giant quadrupole resonance in 40 Ca is studied. It is found that the background characteristics, typical for chaotic systems, strongly affect the fluctuation properties of the strength distribution. In particular, the small components of the wave function obey a scaling law analogous to self-organized systems at the critical state. This appears to be consistent with the Porter-Thomas distribution of the transition strength

  16. Impact-parameter dependence of giant resonance excitations in relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    Gruenschloss, A.; Boretzky, K.; Aumann, T.

    1999-09-01

    Angular distributions of Xe fragments produced in peripheral collisions of a 136 Xe beam (700 MeV/nucleon) with 208 Pb and nat Sn targets were measured. Equivalent sharp-cutoff minimum impact parameters were derived on the basis of a semi-classical description for the electromagnetic excitation of one- and two-phonon giant resonances. The results are compared with current standard parametrizations of minimum impact parameters and with the soft-spheres model using realistic mass density distributions for projectile and targets. (orig.)

  17. Quantum chaos in nuclear single-particle motion and damping of giant resonances

    International Nuclear Information System (INIS)

    Pal, Santanu; Mukhopadhyay, Tapan

    1995-01-01

    The spectral statistics of single particle motion in deformed cavities with axial symmetry are presented. The single particle motion in the cavities considered are non-integrable and the systematics of the fluctuation measures of the spectra reveal a transition from regular to chaotic regime in the corresponding classical systems. Quantitative estimate of the degree of chaos enables us to introduce a correction factor to the one-body wall formula for the damping widths of isoscalar giant resonances. The damping widths calculated with this correction factor give much better agreement with experimental values than earlier calculations of one-body damping widths. (author). 21 refs., 5 figs

  18. A particle-hole-rotator coupling model for the giant resonance of carbon-12

    International Nuclear Information System (INIS)

    McDougall, A.; Spicer, B.M.

    1975-01-01

    A collective correlations calculation has been made for the giant resonance of 12 C. The low-lying states are treated as members of two rotational bands, and higher energy low-lying states are included in the coupling procedure in an attempt to examine the connection of these states with structure in the 30-35 MeV region, and to examine a proposed rotational band of states built on the 7.65 MeV (0 + ) level. The calculation fails to transfer strength to the extent expected. (author)

  19. Studies of photonuclear reactions and photon activation analysis in the giant dipole resonance region using microtrons

    International Nuclear Information System (INIS)

    Tran Duc Thiep; Nguyen Van Do; Nguyen Khac Thi; Truong Thi An; Nguyen Ngoc Son

    2004-01-01

    Microtrons are accelerators of electrons and are simultaneous source of Bremsstrahlung photon flux and fission neutrons. In 1982, a microtron of seventeen trajectories Microtron MT - 17 was put into operation at the National Institute of Physics of Vietnam. Though very modest, microtrons are very useful for developing countries such as Vietnam in both fundamental and applied physics research. During the recent years by using the above mentioned MT - 17 and microtrons from other institutes we have carried out different investigation. In this report we present some results obtained in the studies of photonuclear reactions and photon activation analysis in the giant dipole resonance region. (author)

  20. Fine structure of the giant M1 resonance in 90Zr.

    Science.gov (United States)

    Rusev, G; Tsoneva, N; Dönau, F; Frauendorf, S; Schwengner, R; Tonchev, A P; Adekola, A S; Hammond, S L; Kelley, J H; Kwan, E; Lenske, H; Tornow, W; Wagner, A

    2013-01-11

    The M1 excitations in the nuclide 90Zr have been studied in a photon-scattering experiment with monoenergetic and linearly polarized beams from 7 to 11 MeV. More than 40 J(π)=1+ states have been identified from observed ground-state transitions, revealing the fine structure of the giant M1 resonance with a centroid energy of 9 MeV and a sum strength of 4.17(56) μ(N)(2). The result for the total M1 strength and its fragmentation are discussed in the framework of the three-phonon quasiparticle-phonon model.

  1. Magnetic resonance imaging aspects of giant-cell tumours of bone

    International Nuclear Information System (INIS)

    Pereira, Helcio Mendoncça; Marchiori, Edson; Severo, Alessandro

    2014-01-01

    This study aimed to describe the magnetic resonance imaging (MRI) features of giant-cell tumours of bone. We analysed the clinical and MRI features of patients diagnosed with giant-cell tumours of bone confirmed by histopathology at our institution between 2010 and 2012. The peak incidence was between the second and third decades of life. There was no gender predominance. The most frequent locations were the knee and wrist. Pain and swelling were the prevailing symptoms. Fifty-one per cent of the patients were found to have associated secondary aneurysmal bone cysts on histopathology. On MRI, lesions demonstrated signal intensity equal to that of skeletal muscle on T1-weighted images and low signal intensity on T2-weighted images in 90% of cases. In gadolinium-enhanced T1-weighted images, 76.6% of cases demonstrated heterogeneous enhancement. We observed cystic components involving more than 50% of the lesion in 17 cases (56.6%). There was extra-osseous involvement in 13 cases (43.3%). MRI offers a valuable diagnostic tool for giant-cell tumours of bone. Contrast-enhanced MRI can distinguish between cystic and solid components of the tumour. MRI is also the imaging modality of choice for evaluation of soft-tissue involvement, offering a complete preoperative diagnosis.

  2. Giant cell tumor of the tendon sheath of the hand - magnetic resonance image and orthopaedic treatment

    International Nuclear Information System (INIS)

    Kirova, G.; Monovska, T.; Jablanski, V.; Alexieva, K.; Velev, M.

    2009-01-01

    Giant cell tumour of the tendon sheath (GCT-TS), also known as localized nodular tenosynovitis, is a benign neoplasm that occurs dominantly on the digits. These tumours most commonly occur in patients aged 30-50 years and are associated with degenerative joint disease. GCT-TS usually arises from the synovium of tendon sheets, affecting interfalangeal joints of the hand, feet, ankle and knees. Magnetic Resonance Imaging is able to depict characteristic signal intensities and can accurately assess the tumor size and degree of extent around the phalanx. We present a case of a 36 years-old male patient with GCT-TS in the flexor tendon of his left second finger, diagnosed with Magnetic Resonance imaging. The mass was excised widely with preservation of the flexor tendon without recurrence. (authors)

  3. Neutron components of isoscalar giant quadrupole resonance states in 58,60,62,64Ni

    International Nuclear Information System (INIS)

    Antalik, R.

    1989-01-01

    The neutron-proton matrix element ratios (η) for isoscalar giant quadrupole resonance states of even Ni isotopes are investigated within the framework of the shell model quasiparticle random-phase approximation. The dependence of η ratios on radial neutron and proton ground state density distribution differences (Δ np ) is found to be about 1.0-1.5 Δ np . The theoretical η ratios are 14-23% lower than the hydrodynamical limit. The agreement between theoretical and experimental η ratios is observed for 58 Ni and 60 Ni isotopes. The η ratios for 62 Ni and 64 Ni suggested by the resonance π ± inelastic scattering cannot be interpreted even including the radial variations of the neutron fields. 18 refs.; 3 tabs

  4. Time-dependent shape fluctuations and the giant dipole resonance in hot nuclei: Realistic calculations

    International Nuclear Information System (INIS)

    Alhassid, Y.; Bush, B.; Yale Univ., New Haven, CT

    1990-01-01

    The effects of time-dependent shape fluctuations on the giant dipole resonance (GDR) in hot rotating nuclei are investigated. Using the framework of the Landau theory of shape transitions we develop a realistic macroscopic stochastic model to describe the quadrupole time-dependent shape fluctuations and their coupling to the dipole degrees of freedom. In the adiabatic limit the theory reduces to a previous adiabatic theory of static fluctuations in which the GDR cross section is calculated by averaging over the equilibrium distribution with the unitary invariant metric. Nonadiabatic effects are investigated in this model and found to cause structural changes in the resonance cross section and motional narrowing. Comparisons with experimental data are made and deviations from the adiabatic calculations can be explained. In these cases it is possible to determine from the data the damping of the quadrupole motion at finite temperature. (orig.)

  5. Inelastic electron scattering, fine structure of M1 giant resonances and Gamow-Teller states

    International Nuclear Information System (INIS)

    Richter, A.

    1983-01-01

    Recent progress in obtaining detailed fine structure distributions of magnetic giant resonances in nuclei using high resolution inelastic electron scattering at low energy is discussed. Specific examples chosen are the medium heavy nuclei 40 42 44 48 Ca in which M1 excitations are due to neutron spin-flip transitions and the N=28 isotones 50 Ti, 52 Cr and 54 Fe where in addition also proton excitations contribute to the measured M1 strength. It is found that the M1 strength is very fragmented and considerably quenched in comparison to predictions of shell model calculations in a model space that includes up to 2p-2h excitations. Finally, the old problem of M1 strength in 208 Pb is revisited and the results of a form factor measurement of a recently discovered low lying Jsup(π)=1 + state by nuclear resonance fluorescence are presented. (Auth.)

  6. Deformation dependence of the isovector giant dipole resonance: The neodymium isotopic chain revisited

    Directory of Open Access Journals (Sweden)

    L.M. Donaldson

    2018-01-01

    Full Text Available Proton inelastic scattering experiments at energy Ep=200 MeV and a spectrometer scattering angle of 0° were performed on 144,146,148,150Nd and 152Sm exciting the IsoVector Giant Dipole Resonance (IVGDR. Comparison with results from photo-absorption experiments reveals a shift of resonance maxima towards higher energies for vibrational and transitional nuclei. The extracted photo-absorption cross sections in the most deformed nuclei, 150Nd and 152Sm, exhibit a pronounced asymmetry rather than a distinct double-hump structure expected as a signature of K-splitting. This behaviour may be related to the proximity of these nuclei to the critical point of the phase shape transition from vibrators to rotors with a soft quadrupole deformation potential. Self-consistent random-phase approximation (RPA calculations using the SLy6 Skyrme force provide a relevant description of the IVGDR shapes deduced from the present data.

  7. Deformation dependence of the isovector giant dipole resonance: The neodymium isotopic chain revisited

    Science.gov (United States)

    Donaldson, L. M.; Bertulani, C. A.; Carter, J.; Nesterenko, V. O.; von Neumann-Cosel, P.; Neveling, R.; Ponomarev, V. Yu.; Reinhard, P.-G.; Usman, I. T.; Adsley, P.; Brummer, J. W.; Buthelezi, E. Z.; Cooper, G. R. J.; Fearick, R. W.; Förtsch, S. V.; Fujita, H.; Fujita, Y.; Jingo, M.; Kleinig, W.; Kureba, C. O.; Kvasil, J.; Latif, M.; Li, K. C. W.; Mira, J. P.; Nemulodi, F.; Papka, P.; Pellegri, L.; Pietralla, N.; Richter, A.; Sideras-Haddad, E.; Smit, F. D.; Steyn, G. F.; Swartz, J. A.; Tamii, A.

    2018-01-01

    Proton inelastic scattering experiments at energy Ep = 200 MeV and a spectrometer scattering angle of 0° were performed on 144,146,148,150Nd and 152Sm exciting the IsoVector Giant Dipole Resonance (IVGDR). Comparison with results from photo-absorption experiments reveals a shift of resonance maxima towards higher energies for vibrational and transitional nuclei. The extracted photo-absorption cross sections in the most deformed nuclei, 150Nd and 152Sm, exhibit a pronounced asymmetry rather than a distinct double-hump structure expected as a signature of K-splitting. This behaviour may be related to the proximity of these nuclei to the critical point of the phase shape transition from vibrators to rotors with a soft quadrupole deformation potential. Self-consistent random-phase approximation (RPA) calculations using the SLy6 Skyrme force provide a relevant description of the IVGDR shapes deduced from the present data.

  8. Duality and supersymmetric monopoles

    International Nuclear Information System (INIS)

    Gauntlett, J.P.

    1998-01-01

    Exact duality in supersymmetric gauge theories leads to highly non-trivial predictions about the moduli spaces of BPS monopole solutions. These notes attempt to be a pedagogical review of the current status of these investigations. (orig.)

  9. Discovery of the monopole

    Energy Technology Data Exchange (ETDEWEB)

    Galitskii, V [Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Atomnoj Ehnergii

    1978-04-01

    An experiment is described conducted in Berkeley in which the magnetic monopole was first detected. The objections are reported of prof. Fowler (U.K.) and prof. Alvarez (U.S.A.) permitting a different interpretation of experimental data.

  10. Giant quadrupole resonance in 24Mg, 27Al, and 28Si

    International Nuclear Information System (INIS)

    Youngblood, D.H.; Rozsa, C.M.; Moss, J.M.; Brown, D.R.; Bronson, J.D.

    1977-01-01

    The giant-resonance region of 24 Mg, 27 Al, and 28 Si was studied by inelastic scattering of 126-MeV α particles. In contrast to results at 96 MeV, considerable clustering of E2 strength was observed for 27 Al at E/sub x/ approx. 20.1 MeV with GAMMA approx. 7.6 MeV exhausting about 35% of the E2 energy weighted sum rule. E2 strength was also located in 24 Mg in two clusters of states at E-bar/sub x/ approx. 18.2, 24.4 MeV; however, contributions from other multipoles cannot be neglected. In 28 Si a multipeaked group was observed at E/sub x/ approx. 19.4 MeV with GAMMA approx. 4 MeV but no L assignment was made. The energy dependence of the cross section for the giant quadrupole resonance was found to be consistent with distorted-wave Born approximation predictions

  11. Breaking of axial symmetry in excited heavy nuclei as identified in giant dipole resonance data

    Energy Technology Data Exchange (ETDEWEB)

    Grosse, E.; Massarczyk, R. [Technische Universitaet Dresden, Institute of Nuclear and Particle Physics, Dresden (Germany); Junghans, A.R. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Dresden (Germany)

    2017-11-15

    A recent theoretical prediction of a breaking of axial symmetry in quasi all heavy nuclei is confronted to a new critical analysis of photon strength functions of nuclei in the valley of stability. For the photon strength in the isovector giant dipole resonance (IVGDR) regime a parameterization of GDR shapes by the sum of three Lorentzians (TLO) is extrapolated to energies below and above the IVGDR. The impact of non-GDR modes adding to the low energy slope of photon strength is discussed including recent data on photon scattering and other radiative processes. These are shown to be concentrated in energy regions where various model calculations predict intermediate collective strength; thus they are obviously separate from the IVGDR tail. The triple Lorentzian (TLO) ansatz for giant dipole resonances is normalized in accordance to the dipole sum rule. The nuclear droplet model with surface dissipation accounts well for positions and widths without local, nuclide specific, parameters. Very few and only global parameters are needed when a breaking of axial symmetry already in the valley of stability is admitted and hence a reliable prediction for electric dipole strength functions also outside of it is expected. (orig.)

  12. The 132Sn giant dipole resonance as a constraint on nuclear matter properties

    Science.gov (United States)

    Roach, Brandon; Bonasera, Giacomo; Shlomo, Shalom

    2015-10-01

    Nuclear giant resonances provide a sensitive method for constraining the properties of nuclear matter (NM) - many of which have large uncertainties - and thereby improve the nuclear energy-density functional. In this work, self-consistent Hartree-Fock random-phase approximation (HF-RPA) theory was employed to calculate the strength function and energy of the isovector giant dipole resonance (IVGDR) in the doubly-magic 132Sn nucleus. Several (17) commonly-used Skyrme-type interactions were employed. The correlations between the IVGDR centroid energy and each nuclear matter property were explored, as were correlations between the nuclear matter properties and the 132Sn neutron skin thickness rn -rp . Experimental data for the IVGDR centroid energy was used to constrain the symmetry energy density, the symmetry energy, and its first and second derivatives, respectively, of NM. Further investigation, particularly of nuclides far from stability, will be needed to extend the nuclear energy-density functional to the extremes of density and neutron abundance found in neutron stars and astrophysical nucleosynthesis environments.

  13. Total and differential cross sections for pion production via coherent isobar and giant resonance formation in heavy-ion collisions

    International Nuclear Information System (INIS)

    Deutchman, P.A.; Norbury, J.W.; Townsend, L.W.

    1985-01-01

    A quantal many-body formalism is presented that investigates pion production through the coherent formation of a nucleonic isobar in the projectile and its subsequent decay to various pion charge states along with concomitant excitation of the target to a coherent spin-isospin giant resonance via a peripheral collision of relativistic heavy ions. Total cross sections as a function of the incident energy per nucleon and Lorentz-invariant differential cross sections as a function of pion energy and angle are calculated. It is shown that the pion angular distributions, in coincidence with the target giant resonance excitations, might provide a well-defined signature for these coherent processes

  14. Electric quadrupole giant resonance in the photofission of sup(238)U IFUSP-P--140

    International Nuclear Information System (INIS)

    Bhandari, B.S.; Arruda Neto, J.D.T.; Herdade, S.B.; Nascimento, I.C.

    1978-02-01

    The 238 U nucleus was studied measuring the electrofission yield and angular distributions of fission fragments, in the energy range of 5.5 to 28.3 MeV, using a new method of analysis. An E2 isoscalar giant resonance was found in the photofission cross section of 238 U. This resonance exhausts (71 + -7)% of the EWSR and is located at 9.9 + -0.2 MeV with a width of 6.8 + -0.4 MeV. The position of this resonance is in reasonable agreement with the Bohr and Mottelson prediction (58.Asup( - 1/3MeV). The width of 6.8 + -0.4 MeV is compatible with a possible triple splitting of the resonance. From the angular distributions of photofission fragments and yield measurements of multipoles other than E1, evidence of an M1 mixture in the energy region 6-7 MeV was found

  15. Giant thermo-optical relaxation oscillations in millimeter-size whispering gallery mode disk resonators.

    Science.gov (United States)

    Diallo, Souleymane; Lin, Guoping; Chembo, Yanne K

    2015-08-15

    In this Letter, we show that giant thermo-optical oscillations can be triggered in millimeter (mm)-size whispering gallery mode (WGM) disk resonators when they are pumped by a resonant continuous-wave laser. Our resonator is an ultrahigh-Q barium fluoride cavity that features a positive thermo-optic coefficient and a negative thermo-elastic coefficient. We demonstrate for the first time, to our knowledge, that the complex interplay between these two thermic coefficients and the intrinsic Kerr nonlinearity yields very sharp slow-fast relaxation oscillations with a slow timescale that can be exceptionally large, typically of the order of 1 s. We use a time-domain model to gain understanding into this instability, and we find that both the experimental and theoretical results are in excellent agreement. The understanding of these thermal effects is an essential requirement for every WGM-related application and our study demonstrates that even in the case of mm-size resonators, such effects can still be accurately analyzed using nonlinear time-domain models.

  16. Cardiac Sarcoidosis or Giant Cell Myocarditis? On Treatment Improvement of Fulminant Myocarditis as Demonstrated by Cardiovascular Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Hari Bogabathina

    2012-01-01

    Full Text Available Giant cell myocarditis, but not cardiac sarcoidosis, is known to cause fulminant myocarditis resulting in severe heart failure. However, giant cell myocarditis and cardiac sarcoidosis are pathologically similar, and attempts at pathological differentiation between the two remain difficult. We are presenting a case of fulminant myocarditis that has pathological features suggestive of cardiac sarcoidosis, but clinically mimicking giant cell myocarditis. This patient was treated with cyclosporine and prednisone and recovered well. This case we believe challenges our current understanding of these intertwined conditions. By obtaining a sense of severity of cardiac involvement via delayed hyperenhancement of cardiac magnetic resonance imaging, we were more inclined to treat this patient as giant cell myocarditis with cyclosporine. This resulted in excellent improvement of patient’s cardiac function as shown by delayed hyperenhancement images, early perfusion images, and SSFP videos.

  17. Concerning the generation of geomagnetic giant pulsations by drift-bounce resonance ring current instabilities

    Directory of Open Access Journals (Sweden)

    K.-H. Glassmeier

    Full Text Available Giant pulsations are nearly monochromatic ULF-pulsations of the Earth's magnetic field with periods of about 100 s and amplitudes of up to 40 nT. For one such event ground-magnetic observations as well as simultaneous GEOS-2 magnetic and electric field data and proton flux measurements made in the geostationary orbit have been analysed. The observations of the electromagnetic field indicate the excitation of an odd-mode type fundamental field line oscillation. A clear correlation between variations of the proton flux in the energy range 30-90 keV with the giant pulsation event observed at the ground is found. Furthermore, the proton phase space density exhibits a bump-on-the-tail signature at about 60 keV. Assuming a drift-bounce resonance instability as a possible generation mechanism, the azimuthal wave number of the pulsation wave field may be determined using a generalized resonance condition. The value determined in this way, 
    m
    = - 21 ± 4, is in accord with the value m = - 27 ± 6 determined from ground-magnetic measurements. A more detailed examination of the observed ring current plasma distribution function f shows that odd-mode type eigenoscillations are expected for the case ∂f / ∂W > 0, much as observed. This result is different from previous theoretical studies as we not only consider local gradients of the distribution function in real space, but also in velocity space. It is therefore concluded that the observed giant pulsation is the result of a drift-bounce resonance instability of the ring current plasma coupling to an odd-mode fundamental standing wave. The generation of the bump-on-the-tail distribution causing ∂f / ∂W > 0 can be explained due to velocity dispersion of protons injected into the ring current. Both this velocity dispersion and the necessary substorm activity causing the injection of protons into the nightside magnetosphere are observed

  18. Concerning the generation of geomagnetic giant pulsations by drift-bounce resonance ring current instabilities

    Directory of Open Access Journals (Sweden)

    K.-H. Glassmeier

    1999-03-01

    Full Text Available Giant pulsations are nearly monochromatic ULF-pulsations of the Earth's magnetic field with periods of about 100 s and amplitudes of up to 40 nT. For one such event ground-magnetic observations as well as simultaneous GEOS-2 magnetic and electric field data and proton flux measurements made in the geostationary orbit have been analysed. The observations of the electromagnetic field indicate the excitation of an odd-mode type fundamental field line oscillation. A clear correlation between variations of the proton flux in the energy range 30-90 keV with the giant pulsation event observed at the ground is found. Furthermore, the proton phase space density exhibits a bump-on-the-tail signature at about 60 keV. Assuming a drift-bounce resonance instability as a possible generation mechanism, the azimuthal wave number of the pulsation wave field may be determined using a generalized resonance condition. The value determined in this way,  m = - 21 ± 4, is in accord with the value m = - 27 ± 6 determined from ground-magnetic measurements. A more detailed examination of the observed ring current plasma distribution function f shows that odd-mode type eigenoscillations are expected for the case ∂f / ∂W > 0, much as observed. This result is different from previous theoretical studies as we not only consider local gradients of the distribution function in real space, but also in velocity space. It is therefore concluded that the observed giant pulsation is the result of a drift-bounce resonance instability of the ring current plasma coupling to an odd-mode fundamental standing wave. The generation of the bump-on-the-tail distribution causing ∂f / ∂W > 0 can be explained due to velocity dispersion of protons injected into the ring current. Both this velocity dispersion and the necessary substorm activity causing the injection of protons into the nightside magnetosphere are observed.Key words. Magnetospheric physics (energetic particles , trapped

  19. The structure of the Gamow-Teller giant resonance and consequences for beta-delayed neutron spectra and element synthesis

    International Nuclear Information System (INIS)

    Klapdor, H.V.

    1976-01-01

    Recent results in β-delayed neutron emission are interpreted by structure of the Gamow-Teller giant resonance not included in the 'gross-theory' of β-decay. Inclusion of this structure of the β-decay function is important for calculations of β-decay production rates for heavy nuclides by astrophysical processes and thermonuclear explosions. (Auth.)

  20. Interacting sp-boson model with isospin: an unified description of giant multipole resonances and other collective motions

    International Nuclear Information System (INIS)

    Chen, C.H.-T.

    1980-10-01

    A unified description of the following classes of nuclear collective states in terms of an interacting sp-boson model is proposed: (i) Low-lying collective states in the light nuclei, both odd-odd and even-even; (ii) Giant multipole resonances (GMR), and (iii) pairing collective motions. (Author) [pt

  1. Massive magnetic monopoles in cosmology and astrophysics

    International Nuclear Information System (INIS)

    Kolb, E.W.

    1984-01-01

    The astrophysical and cosmological consequences of magnetic monopoles are discussed. The production of monopoles during phase transition in the early universe is addressed, and proposals which have been made to alleviate the monopole problem are summarized. Astrophysical limits on galactic magnetic monopoles are discussed along with experimental efforts to detect monopoles. Finally, monopole-induced proton decay is addressed. 48 references

  2. Sequential changes of magnetic resonance images of intracavernous giant aneurysm following carotid ligation

    International Nuclear Information System (INIS)

    Kinjo, Toshihiko; Mukawa, Jiro; Takara, Eiichi; Mekaru, Susumu; Ishikawa, Yasunari

    1986-01-01

    A case of intracavernous giant aneurysm treated by combined carotid ligation and extracranial-intracranial vein-graft bypass is reported with special reference to the sequential changes of Magnetic Resonance Images (MRI). A 29-year-old female was admitted to our clinic with complaint of diplopia. She had no neurological deficit except for left abducens palsy. Left carotid angiogram revealed an intracavernous giant aneurysm, and vertebral angiogram revealed a fenestration at right and an aneurysm-like buldging at left vertebral artery. Gradual carotid occlusion after extracranial-intracranial bypass via grafted saphnous vein was successfully performed without any neurological complications. Sequential changes of MRI were as follows: The aneurysm was shown by absent intensity both in spin echo (SE) and inversion recovery (IR) methods before the treatment. It became isointensity in SE and two-tone intensity, iso at the center and high at the margin, in IR 15 days after, and, furtheremore, became slight high intensity in SE but decreased in two-tone intensity, low at the center and high at the margin, in IR 37 days after complete carotid occlusion. Coronal view was usefull to understand anatomical relationship. In conclusion, MRI, especially coronal IR method is of more diagnostic value than X-ray CT to follow the thrombosis of intracavernous aneurysm. (author)

  3. Quantal and thermal dampings of the hot giant dipole resonance due to complex configuration mixing

    CERN Document Server

    Dang, N D; Arima, A

    1999-01-01

    An approach is presented to study the width of the giant dipole resonance (GDR) at non-zero temperature T, which includes all forward-going processes up to two-phonon ones. Calculations are performed in sup 1 sup 2 sup 0 Sn and sup 2 sup 0 sup 8 Pb. An overall agreement between theory and experiment is found. The total width of the GDR due to coupling of the GDR phonon to all ph, pp and hh configurations increases sharply as T increases up to T approx 3 MeV and saturates at T approx 4-6 MeV. The quantal width GAMMA sub Q due to coupling to ph configurations decreases with increasing T. It is almost independent of T if the contribution of two-phonon processes at T not =0 is omitted.

  4. Giant angular resonance and the structure of the lowest-lying nuclear states

    International Nuclear Information System (INIS)

    Mikhajlov, I.N.; Usmanov, P.N.; Yuldashbaeva, Eh.Kh.

    1987-01-01

    The analysis is given of the Hamiltonian of the two-rotor model, which is based on the assumption that the giant angular resonance exists, i.e. that it is possible to rotate the neutron component of a deformed nucleus as a whole with respect to the proton component. The realization of the projections on the intrinsic axes of the angular momentum operators is found, the Hamiltonian matrix is determined in the basis convenient for the case of strong neutron-proton coupling. The spectrum of the two-rotor model is determined taking into account the nondiagonal matrix elements in the lowest order of the perturbation theory. The g factors and the probabilities of the M1 transitions are discussed

  5. Damping width of giant dipole resonances of cold and hot nuclei: A macroscopic model

    International Nuclear Information System (INIS)

    Mughabghab, S.F.; Sonzogni, A.A.

    2002-01-01

    A phenomenological macroscopic model of the giant dipole resonance (GDR) damping width of cold and hot nuclei with ground-state spherical and near-spherical shapes is developed. The model is based on a generalized Fermi liquid model which takes into account the nuclear surface dynamics. The temperature dependence of the GDR damping width is accounted for in terms of surface and volume components. Parameter-free expressions for the damping width and the effective deformation are obtained. The model is validated with GDR measurements of the following nuclides: 39,40 K, 42 Ca, 45 Sc, 59,63 Cu, 109-120 Sn, 147 Eu, 194 Hg, and 208 Pb, and is compared with the predictions of other models

  6. Temperature dependence and fragmentation of the particle-hole giant resonances

    International Nuclear Information System (INIS)

    Seva, E.C.; Sofia, H.M.

    1997-01-01

    We evaluate the spreading width of the giant multipole resonances at finite temperature using the discontinuity in the second derivative of the Green close-quote s function of the vibrational boson, in the Matsubara close-quote s framework. Our method allows us to identify the processes that contribute to the spreading width in terms of the Feynman diagrammatic expansion of the full boson propagator. We have applied the calculation of the spreading width to the 208 Pb and the 90 Zr obtaining an increment of the spreading width with the temperature. We have not reached any saturation of the spreading width increment, at least up to the temperature of our calculation. copyright 1997 The American Physical Society

  7. Study of the giant dipole resonance built on highly excited states in Sn and Dy nuclei

    International Nuclear Information System (INIS)

    Stolk, A.

    1988-01-01

    A study is presented of the giant dipole resonance built on highly excited states. The aim is to get more detailed information on the properties of the GDR and to use it as a tool for the investigation of nuclear structure at high excitation energy. The high energy γ-rays seen from the decay of excited state GDRs in heavy ion fusion reactions reflect the average properties of the states populated by the γ-emission. The measurements at different initial excitation energies of 114 Sn provide information on the nuclear level density near the particle separation energy at an average angular momentum of 10ℎ. The study of shape changes at very high spin in 152-156 Dy nuclei is presented. A theoretical model developed to describe fusion-evaporation reactions is presented. 149 refs.; 63 figs.; 13 tabs

  8. Fine structure of the isoscalar giant quadrupole resonance in 40Ca due to Landau damping?

    International Nuclear Information System (INIS)

    Usman, I.; Buthelezi, Z.; Carter, J.; Cooper, G.R.J.; Fearick, R.W.; Foertsch, S.V.; Fujita, H.; Fujita, Y.; Kalmykov, Y.; Neumann-Cosel, P. von; Neveling, R.; Papakonstantinou, P.; Richter, A.; Roth, R.; Shevchenko, A.; Sideras-Haddad, E.; Smit, F.D.

    2011-01-01

    The fragmentation of the Isoscalar Giant Quadrupole Resonance (ISGQR) in 40 Ca has been investigated in high energy-resolution experiments using proton inelastic scattering at E p =200 MeV. Fine structure is observed in the region of the ISGQR and its characteristic energy scales are extracted from the experimental data by means of a wavelet analysis. The experimental scales are well described by Random Phase Approximation (RPA) and second-RPA calculations with an effective interaction derived from a realistic nucleon-nucleon interaction by the Unitary Correlation Operator Method (UCOM). In these results characteristic scales are already present at the mean-field level pointing to their origination in Landau damping, in contrast to the findings in heavier nuclei and also to SRPA calculations for 40 Ca based on phenomenological effective interactions, where fine structure is explained by the coupling to two-particle-two-hole (2p-2h) states.

  9. Origin of fine structure of the giant dipole resonance in s d -shell nuclei

    Science.gov (United States)

    Fearick, R. W.; Erler, B.; Matsubara, H.; von Neumann-Cosel, P.; Richter, A.; Roth, R.; Tamii, A.

    2018-04-01

    A set of high-resolution zero-degree inelastic proton scattering data on 24Mg, 28Si, 32S, and 40Ca provides new insight into the long-standing puzzle of the origin of fragmentation of the giant dipole resonance (GDR) in s d -shell nuclei. Understanding is achieved by comparison with random phase approximation calculations for deformed nuclei using for the first time a realistic nucleon-nucleon interaction derived from the Argonne V18 potential with the unitary correlation operator method and supplemented by a phenomenological three-nucleon contact interaction. A wavelet analysis allows one to extract significant scales both in the data and calculations characterizing the fine structure of the GDR. The fair agreement for scales in the range of a few hundred keV supports the surmise that the fine structure arises from ground-state deformation driven by α clustering.

  10. Monopoles and bags

    International Nuclear Information System (INIS)

    Jun, J.H.

    1980-01-01

    From chapter III to chapter V properties of U(1) monopole are discussed by calculating radiative capture of an electron by a monopole, the scattering cross section of an electron by a dyon, and the bound state properties of the electron-dyon system. The Lipkin-Weisberger-Peshkin difficulty is overcome by an introduction of a small magnetic moment of the electron. In chapter VI, the linear deformation of the Prasad-Sommerfield solution of the t'Hooft Polyakov monopole is discussed, where we found all the deformed solutions analytically. In chapter VII and VIII, the question of a deformed bag and properties of an excited bag are discussed. The excited D-state is mixed with S-state to give the correct value of g/sub A/. Initially, in chapter II, energy ratios for trimuons produced through a heavy-lepton cascade decay are calculated

  11. The description of neutron and giant resonances within the quasiparticle-phonon nuclear model

    International Nuclear Information System (INIS)

    Soloviev, V.G.

    1978-01-01

    The general assumptions of the quasiparticle-phonon model of complex nuclei are given. The choice of the model Hamiltonian as an average field and residual forces is discussed. The phonon description and quasiparticle-phonon interaction are presented. The system of basic equations and their approximate solutions are obtained. The approximation is chosen so as to obtain the most correct description of few-quasiparticle components rather than of the whole wave function. The method of strength functions is presented, which plays a decisive role in practical realization of the quasiparticle-phonon model for the description of some properties of complex nuclei. The range of applicability of the quasiparticle-phonon nuclear model is determined as few-quasiparticle components of the wave functions at low, intermediate and high excitation energies averaged in a certain energy interval. The fragmentation of single-particle states in deformed nuclei is studied within this model. The dependence of neutron strength functions on the excitation energy is investigated for the transfer reactions of the type (d,p) and (d,t). The s - ,p - , and d-wave neutron strength functions are calculated at the neutron binding energy Bsub(n). A satisfactory agreement with experiment is obtained. A correct description of the radiative strength functions in spherical nuclei is obtained. The influence of the tail of the giant dipole resonance on the E1-strength functions is studied. The energies and EΛ-strength functions for giant multipole resonances in spherical and deformed nuclei are calculated. A correct description of their widths is obtained. (author)

  12. Scattering on magnetic monopoles

    International Nuclear Information System (INIS)

    Petry, H.R.

    1980-01-01

    The time-dependent scattering theory of charged particles on magnetic monopoles is investigated within a mathematical frame-work, which duely pays attention to the fact that the wavefunctions of the scattered particles are sections in a non-trivial complex line-bundle. It is found that Moeller operators have to be defined in a way which takes into account the peculiar long-range behaviour of the monopole field. Formulas for the scattering matrix and the differential cross-section are derived, and, as a by-product, a momentum space picture for particles, which are described by sections in the underlying complex line-bundle, is presented. (orig.)

  13. Monopoles, vortices, and confinement

    International Nuclear Information System (INIS)

    Mack, G.; Pietarinen, E.

    1981-10-01

    An exact relation is established between an SO(3) lattice gauge theory model without monopoles, and a corresponding SU(2) model. Elimination of the monopoles (and their strings) leads to a substantial lowering of the entropy of thin vortices and a corresponding decrease of the string tension for low γ. This is revealed by approximate calculations of the vortex free energy and is confirmed by Monte Carlo data. The value of the physical transition temperature to 'hot gluon soup' is also lowered considerably. (orig.)

  14. Tri-band small monopole antenna based on SRR units

    Directory of Open Access Journals (Sweden)

    Gehan Shehata

    2015-12-01

    Full Text Available In this paper a novel design for a tri-band monopole antenna coupled with metamaterial units is introduced. The proposed antenna was designed to cover WiMAX (2.5, 3.5 and WLAN (5.2 bands. In our proposal, a coplanar waveguide (CPW fed circular-disk monopole antenna is coupled with three split ring resonator (SRR units which exist on its back side. In our design a monopole antenna and SRR units are designed first to resonate at 5.2 GHz and 2.5 GHz respectively. In addition, antenna is loaded with post to force resonance at 3.5 GHz. SRR units are used for 2.5 GHz resonance to miniaturize antenna size, and our proposed antenna considered an electrically small antenna (ESA at its first resonance frequency. Simulated and measured results exhibit a good agreement that validate our design.

  15. Nuclear fluid dynamics with long-mean-free-path dissipation: Multipole vibrations and isoscalar giant resonance widths

    International Nuclear Information System (INIS)

    Hasse, R.W.; Ghosh, G.

    1982-01-01

    The long-mean-free-path nuclear fluid dynamics is extended to include damping. First the damping stress is derived from the solution of the Boltzmann equation for a breathing spherical container filled with a Fermi gas. Then the corresponding damping force is incorporated into Euler equations of motion and energies and widths of low lying collective resonances are computed as eigenfrequencies of a vibrating nucleus under surface tension and Coulomb potential as well as the high lying isoscalar giant resonances as eigenfrequencies of an elastic nucleus. Maximum damping is obtained if the particle frequency approximately resonates with the wall frequency. Theoretical results are compared with experimental data and future improvements are indicated

  16. Search for Magnetic Monopoles

    CERN Multimedia

    2002-01-01

    This experiment is proposed to investigate the possible production of magnetic monopoles at the ISR. Very different values are in principle possible for the magnetic charge of such objects, and the present experiment intends to cover a range of magnetic charges from g, to 12 g, where g is the classical minimum charge of the Dirac theory, .ce g = 1/2e The detector consists of three double layers of solid track detector, which are only sensitive to highly ionizing particles, such as monopoles should be. The detector is placed directly in the vacuum chamber, to avoid the large energy losses that a monopole would suffer in a solid wall. A solenoidal magnet is placed between the intersection region and the detector and around the detector itself, in order to accelerate monopoles to an energy such that they are able to traverse the successive sensitive layers of the detector. The thickness of the sensitive layers is chosen to avoid confusion with possible background arising from highly ionizing ions. The experiment...

  17. Discovery of the monopole

    International Nuclear Information System (INIS)

    Galitskij, V.

    1978-01-01

    An experiment is described conducted in Berkeley in which the magnetic monopole was first detected. The objections are reported of prof. Fowler (U.K.) and prof. Alvarez (U.S.A.) permitting a different interpretation of experimental data. (Z.J.)

  18. Nonlinear superposition of monopoles

    International Nuclear Information System (INIS)

    Forgacs, P.; Horvath, Z.; Palla, L.

    1981-04-01

    With the aid of Baecklund transformations the authors construct exact multimonopole solutions of the axially and mirror-symmetric Bogomolny equations. The explicit form of the length of the Higgs field is given and is studied both analytically and numerically. The energy density for monopoles with charges 2,3,4,5 is also calculated. (author)

  19. Compact, Frequency Reconfigurable, Printed Monopole Antenna

    Directory of Open Access Journals (Sweden)

    Ricardo Gonçalves

    2012-01-01

    Full Text Available This paper proposes a possible implementation of a compact printed monopole antenna, useful to operate in UMTS and WLAN bands. In order to accomplish that, a miniaturization technique based on the application of chip inductors is used in conjunction with frequency reconfiguration capability. The chip inductors change the impedance response of the monopole, allowing to reduce the resonant frequency. In order to be able to operate the antenna in these two different frequencies, an antenna reconfiguration technique based on PIN diodes is applied. This procedure allows the change of the active form of the antenna leading to a shift in the resonant frequency. The prototype measurements show good agreement with the simulation results.

  20. On some aspects of the semiclassical approach to giant resonances of rotating nuclei

    International Nuclear Information System (INIS)

    Winter, J.

    1985-01-01

    Quadrupole and isovector dipole resonances of rotating nuclei are investigated in the frame-work of Vlasov equations transformed to a rotating system of reference, which are based on the time-dependent Hartree-method for schematic forces. The parameter free model of the self-consistent vibrating harmonic oscillator potential for the quadrupole mode is extended to a coupling to rotation, which also includes large amplitude behaviour. A generalization to an exactly solvable two-liquid model describing the isovector mode is established; for rotating nuclei Hilton's explicit result for the eigenfrequencies is obtained. - The advantage of using the concept of the classical kinetic momentum in a rotating system also in quantum-mechanical descriptions is demonstrated. It completes the standard transformation of density matrices by a time-odd part realized in a phase-factor and permits a more direct interpretation of rotation effects in terms of the classical forces of inertia. - In its generalization from constant angular velocity to constant angular momentum, our model is used to demonstrate that cranking calculations of rotating giant resonances should be corrected for an oscillation of the cranking parameter to assure angular-momentum conservation. (orig.)

  1. Experimental searches for magnetic monopoles

    International Nuclear Information System (INIS)

    Ross, R.R.

    1976-01-01

    Analysis of the sensitivity of previous negative searches for magnetic monopoles shows that they constitute prior evidence against the monopole interpretation of the event reported as ''evidence for detection of a moving magnetic monopole''. The strength of the evidence varies with the unknown mass of the monopole. For M less than or equal to 10 5 GeV, odds are greater than 10 6 : 1 against. For larger masses, the limits depend strongly on assumptions about the range of monopoles and the threshold for detection of monopole tracks in obsidian. In no case are the odds, less than 8 : 1 and they may be no less than 8000 : 1 against. Since the reported event may also be due to an electrically charged heavy particle, it is probably not due to a monopole

  2. Main channels of the decay of the giant dipole resonance in the 20,22Ne nuclei and isospin splitting of the giant dipole resonance in the 22Ne nucleus

    International Nuclear Information System (INIS)

    Varlamov, V.V.; Stepanov, M.E.

    2002-01-01

    Data published in the literature on various photonuclear reactions for the 20,22 Ne isotopes and for their natural mixture are analyzed with the aim of exploring special features of the decay of giant-dipole-resonance states in these two isotopes. With the aid of data on the abundances of the isotopes and on the energy reaction thresholds, the cross sections for the reactions 20,22 Ne[(γ, n) + (γ, np)] and 20,22 Ne[(γ, p) + (γ, np)] are broken down into the contributions from the one-nucleon reactions (γ, n) and (γ, p) and the contributions from the reactions (γ, np). The cross sections evaporation model used here to treat the deexcitation of residual nucle(γ, p) 19,21 F in the energy range E γ = 16.0-28.0 MeV and the cross sections for the reactions 20,22 Ne(γ, np) 18,20 F in the energy range E γ = 23.3-28.0 MeV are estimated. The behavior of the cross-section ratio r = σ(γ, p)/σ(γ, n) for the 22 Ne nucleus as a function of energy is analyzed, and the isospin components of the giant dipole resonance in the 22 Ne nucleus are identified. The contributions of the isospin components of the giant dipole resonance in the 22 Ne nucleus to the cross sections for various photonuclear reactions are determined on the basis of an analysis of the diagram of the excitation and decay of pure isospin states in the 22 Ne nucleus and in nuclei neighboring it, which are members of the corresponding isospin multiplets. The isospin splitting of the giant dipole resonance and the ratio of the intensities of the isospin components are determined to be ΔE = 4.57 ± 0.69 MeV and R = 0.24 ± 0.04, respectively

  3. Giant resonance spectroscopy of 40Ca with the (e,e'x) reaction (I): Experiments and overview of results

    International Nuclear Information System (INIS)

    Diesener, H.; Helm, U.; Neumann-Cosel, P. von; Richter, A.; Schrieder, G.; Stascheck, A.; Stiller, A.; Carter, J.

    2001-01-01

    The 40 Ca(e,e'x; x=p,α) reaction has been measured in the giant resonance excitation region for E x ≅8-26 MeV. The present article is the first out of three describing the experiments and giving an overview of the results. Data were taken at four momentum transfers in the range q=0.26-0.66 fm -1 . Angular correlations for decay to the ground state and low-lying states of 39 K and 36 Ar could be extracted as a function of excitation energy in 40 Ca. Excitation energy spectra integrated over the particle emission angle were generated for the various resolved decay channels. Comparisons of the giant resonance cross-section distributions with results using other electromagnetic or hadronic probes have been made and good agreement is found in most cases

  4. Modification of the Xe 4d giant resonance by the C60 shell in molecular Xe at C60

    International Nuclear Information System (INIS)

    Amusia, M. Ya.; Baltenkov, A. S.; Chernysheva, L. V.; Felfli, Z.; Msezane, A. Z.

    2006-01-01

    It is demonstrated that in photoabsorption of the 4d 10 subshell of a Xe atom in molecular Xe at C 60 , the 4d giant resonance that characterizes the isolated Xe atom is distorted significantly. The reflection of photoelectron waves by the C 60 shell leads to profound oscillations in the photoionization cross section such that the Xe giant resonance is transformed into four strong peaks. Similarly, the angular anisotropy parameters, both dipole and nondipole, are also modified. The method of calculation is based on the approximation of the C 60 shell by an infinitely thin bubble potential that leaves the sum rule for the 4d-electrons almost unaffected, but noticeably modifies the dipole polarizability of the 4d-shell

  5. On superintegrable monopole systems

    Science.gov (United States)

    Fazlul Hoque, Md; Marquette, Ian; Zhang, Yao-Zhong

    2018-02-01

    Superintegrable systems with monopole interactions in flat and curved spaces have attracted much attention. For example, models in spaces with a Taub-NUT metric are well-known to admit the Kepler-type symmetries and provide non-trivial generalizations of the usual Kepler problems. In this paper, we overview new families of superintegrable Kepler, MIC-harmonic oscillator and deformed Kepler systems interacting with Yang-Coulomb monopoles in the flat and curved Taub-NUT spaces. We present their higher-order, algebraically independent integrals of motion via the direct and constructive approaches which prove the superintegrability of the models. The integrals form symmetry polynomial algebras of the systems with structure constants involving Casimir operators of certain Lie algebras. Such algebraic approaches provide a deeper understanding to the degeneracies of the energy spectra and connection between wave functions and differential equations and geometry.

  6. Monopole and dyon supermultiplets

    International Nuclear Information System (INIS)

    Minakata, H.

    1985-01-01

    The structure of monopole and dyon supermultiplets is elucidated in some supersymmetric gauge theories which admit classical monopole solutions. Our particular emphasis is on the phenomenon of fermion fractionization in supersymmetric theories. It is shown that in the N = 1 and N = 2 supersymmetric Georgi-Glashow models the occurrence of the fermion fractionization is the necessity; the ignorance of it results in the inconsistency in the perturbative calculation of the mass splittings among the members of the supermultiplets. The notable feature of our result is that the degeneracy due to the Jackiw-Rebbi zero mode is not independent of the one required by the supersymmetry, suggesting a nontrivial structure in embedding the topology of Higgs fields into supersymmetric gauge theories

  7. Colour and magnetic monopoles

    International Nuclear Information System (INIS)

    Corrigan, E.; Olive, D.

    1976-01-01

    If the exact gauge symmetry of nature consists of the U(1)sub(EM) generated by the electric charge operator Q and the colour group K, with Q a colour singlet, then, if g is a possible magnetic charge, exp(4πigQ) must equal an element of the colour group. For colour singlet particles this reduces to Dirac's condition eg = n/2. In general, possible monopoles correspond to points of intersection of the colour and electromagnetic groups. If the colour group is semi-simple and compact, there can at most be a finite number p of such points (p = N if K = SU(N)). The existence of non-trivial (not equal to unity) solutions to our condition means that there must be fractionally charged (with p the fraction) coloured particles and magnetic monopoles emanating colour magnetic flux as well as electromagnetic flux. (Auth.)

  8. Voltage control of magnetic monopoles in artificial spin ice

    Science.gov (United States)

    Chavez, Andres C.; Barra, Anthony; Carman, Gregory P.

    2018-06-01

    Current research on artificial spin ice (ASI) systems has revealed unique hysteretic memory effects and mobile quasi-particle monopoles controlled by externally applied magnetic fields. Here, we numerically demonstrate a strain-mediated multiferroic approach to locally control the ASI monopoles. The magnetization of individual lattice elements is controlled by applying voltage pulses to the piezoelectric layer resulting in strain-induced magnetic precession timed for 180° reorientation. The model demonstrates localized voltage control to move the magnetic monopoles across lattice sites, in CoFeB, Ni, and FeGa based ASI’s. The switching is achieved at frequencies near ferromagnetic resonance and requires energies below 620 aJ. The results demonstrate that ASI monopoles can be efficiently and locally controlled with a strain-mediated multiferroic approach.

  9. Solitons, monopoles and bags

    International Nuclear Information System (INIS)

    Rajasekaran, G.

    1978-01-01

    Recent developments in the theory of solitons and related objects in the fields of high energy physics and nuclear physics are reviewed. The aim is to concentrate on the physical aspects and explain why these objects have awakened the interest of physicists. The physics of solitons is discussed with the help of a simple one-dimensional soliton. Then the physically more interesting monopole-soliton is considered and its connection with the original Dirac monopole is pointed out. The ''revolutionary'' possibility of making fermions as composites of bosons is indicated. Both the one-dimensional solitons and the monopole-soliton are examples of ''topological solitons'' and the role of topology in the physics of solitons is explained. The possible importance of topological quantum numbers in providing a fundamental understanding of the basic conservation laws of physics is pointed out. Two examples of non-topological solitons namely, the nucleon as a bag of almost-massless quarks and the abnormal nucleons as a bag of almost massless nucleons is discussed. (auth.)

  10. Peripheral collisions of heavy ions induced by 40Ar at intermediate energies: giant resonance high energy structures and projectile fragmentation

    International Nuclear Information System (INIS)

    Blumenfeld, Y.

    1987-09-01

    The results obtained in similar studies at low incident energies are first of all reviewed. The time of flight spectrometer built for the experiments is then described. A study of the properties of the projectile-like fragments shows numerous deviations from the relativistic energy fragmentation model. Evidence for a strong surface transfer reaction component is given and the persistence of mean field effects at intermediate energies is stressed. A calculation of the contribution of the transfer evaporation mechanism to the inelastic spectra shows that this mechanism is responible for the major part of the background measured at high excitation energy and can in some cases induce narrow structures in the spectra. The inelastic spectra shows a strong excitation of the giant quadrupole resonance. In the region between 20 and 80 MeV excitation energy narrow structures are present for all the studied systems. Statistical and Fourier analysises allow to quantify the probabilities of existence, the widths and the excitation energies of these structures. A transfer evaporation hypothesis cannot consistently reproduce all the observed structures. The excitation energies of the structures can be well described by phenomenological laws where the energies are proportional to the -1/3 power of the target mass. Complete calculations of the excitation probabilities of giant resonances and multiphonon states are performed within a model where the nuclear excitation are calculated microscopically in the Random Phase Approximation. It is shown that a possible interpretation of the structures is the excitation of multiphonon states built with 2 + giant resonances [fr

  11. TERRESTRIAL PLANET FORMATION DURING THE MIGRATION AND RESONANCE CROSSINGS OF THE GIANT PLANETS

    International Nuclear Information System (INIS)

    Lykawka, Patryk Sofia; Ito, Takashi

    2013-01-01

    The newly formed giant planets may have migrated and crossed a number of mutual mean motion resonances (MMRs) when smaller objects (embryos) were accreting to form the terrestrial planets in the planetesimal disk. We investigated the effects of the planetesimal-driven migration of Jupiter and Saturn, and the influence of their mutual 1:2 MMR crossing on terrestrial planet formation for the first time, by performing N-body simulations. These simulations considered distinct timescales of MMR crossing and planet migration. In total, 68 high-resolution simulation runs using 2000 disk planetesimals were performed, which was a significant improvement on previously published results. Even when the effects of the 1:2 MMR crossing and planet migration were included in the system, Venus and Earth analogs (considering both orbits and masses) successfully formed in several runs. In addition, we found that the orbits of planetesimals beyond a ∼ 1.5-2 AU were dynamically depleted by the strengthened sweeping secular resonances associated with Jupiter's and Saturn's more eccentric orbits (relative to the present day) during planet migration. However, this depletion did not prevent the formation of massive Mars analogs (planets with more than 1.5 times Mars's mass). Although late MMR crossings (at t > 30 Myr) could remove such planets, Mars-like small mass planets survived on overly excited orbits (high e and/or i), or were completely lost in these systems. We conclude that the orbital migration and crossing of the mutual 1:2 MMR of Jupiter and Saturn are unlikely to provide suitable orbital conditions for the formation of solar system terrestrial planets. This suggests that to explain Mars's small mass and the absence of other planets between Mars and Jupiter, the outer asteroid belt must have suffered a severe depletion due to interactions with Jupiter/Saturn, or by an alternative mechanism (e.g., rogue super-Earths)

  12. Elastic and Raman scattering of photons from the giant dipole resonance

    International Nuclear Information System (INIS)

    Bar-Noy, T.

    1978-12-01

    In the present work we investigated nuclear Raman and elastic scattering of photons from the Giant Dipole Resonance (GDR) of medium and heavy nuclei. The photons beams were obtained from thermal neutron capture on V, Fe, Ni, Cu and Cr discs, utilizing the IRR-2 reactor. Nine targets, 159 Tb, 165 Ho, 175 Lu, 181 Ta, 197 Au, 209 Bi, 232 Th, 237 Np, and 238 U, representing all spherical and deformed nuclei in the region of medium and heavy nuclei, were used. As preliminary works, we discovered and investigated the 11.4 MeV γ-line, measured the attenuation coefficients at 9 and 11.4 MeV, performed a numerical calculation of Delbrueck amplitudes and modified the Simple Rotator Model (SRM). The absolute scattering cross-sections were measured for each scatterer at 4-8 different energies, and angular distributions in the range 90 deg to 140 deg were carried out at 9 MeV and 11.4 MeV. The experimental results were compared with theoretical predictions of the modified SRM and the Dynamic Collective Model (DCM). The results proved that the modified SRM describes appropriately the scattering from the GDR, including elastic and Raman absolute cross-sections and their angular distributions. (author)

  13. Distribution of radiative strength with excitation energy: the E1 and M1 giant resonances

    International Nuclear Information System (INIS)

    Brown, G.E.; Speth, J.

    1979-01-01

    Calculations of the giant dipole resonance in the particle-hole model, employing empirical values for the unperturbed particle and hole energies, have been unsuccessful in pushing the dipole state to a sufficiently high energy. it is argued that unperturbed levels correspondign to an effective mass of m*/m approx. 0.6 to 0.7 should be employed. The couplings of particles and holes to vibrations are the crucial ingredients in these considerations. More generally, it is argued that the effective mass relevant to excitations near the Fermi surface is that corresponding to empirical single-particle levels, m*/m greater than or equal to 1.0. For particle-hole excitations above the Fermi surface, it is a decreasing function of excitation energy, reaching the above values 0.6 to 0.7 for E greater than or equal to 2 dirac constant/b omega, dirac constant/sub omega/ being the shell spacing. This has the consequence of spreading out the M1 strength. A new interpretation of experimental strengths is proposed

  14. Magnetic monopoles and strange matter

    International Nuclear Information System (INIS)

    Sanudo, J.; Segui, A.

    1985-07-01

    We show that, if the density of grand unified monopoles at T approx. = 200 MeV is of the order of or greater than 4.4 * 10 21 cm -3 , they annihilate all of the strange matter produced in the quagmahadron phase transition which the Universe undergoes at this temperature. We also study gravitational capture of monopoles by lumps of strange matter. This yields upper limits on the density of monopoles for different sizes of strange ball. (author)

  15. Global EiBI-monopole

    Directory of Open Access Journals (Sweden)

    JIN Xinghua

    2014-04-01

    Full Text Available A global EiBI-monopole problem is studied under EiBI gravitational theory.The equations of global EiBI-monopole are derived in the curved spacetime and the relation between the spacetime metric and auxiliary metric is found.In the case of a very small parameter,an asymptotic form of equations is given.The series solutions of global EiBI-monopole at infinity are found.

  16. Magnetic Half-Monopole Solutions

    International Nuclear Information System (INIS)

    Teh, Rosy; Lim, Kok-Geng; Koh, Pin-Wai

    2009-01-01

    We present exact SU(2) Yang-Mills-Higgs monopole solutions of one half topological charge. These non-Abelian solutions possess gauge potentials which are singular along either the positive or the negative z-axis and common magnetic fields that are singular only at the origin where the half-monopole is located. These half-monopoles are actually a half Wu-Yang monopole and they can possess a finite point electric charge and become half-dyons. They do not necessarily satisfy the first order Bogomol'nyi equations and they possess infinite energy density at r = 0.

  17. Magnetic monopoles: a status report

    International Nuclear Information System (INIS)

    Carrigan, R.A. Jr.; Trower, W.P.

    1983-03-01

    A solitary, uncorroborated Stanford candidate event is the only evidence that magnetic monpoles derives from Dirac's assertion that monopoles could explain charge quantization and the 't Hooft-Polyakov demonstration that monopoles are an inevitable consequence of many gauge theories currently being used to unify the electroweak (photon-lepton) and nuclear (quark) interactions. The monopole abundance implied by the Stanford event is in clear contradiction to bounds on their number from astronomical data. Fortunately, the already considerable and expanding arsenal of detection techniques are being fashioned to experimentally test the many open questions surrounding monopoles

  18. Fine structure of the isoscalar giant quadrupole resonance from high-resolution inelastic proton scattering experiments

    International Nuclear Information System (INIS)

    Shevchenko, A.

    2005-02-01

    In the present work the phenomenon of fine structure in the region of the isoscalar giant quadrupole resonance in a number of heavy and medium-heavy nuclei is systematically investigated for the first time. High energy-resolution inelastic proton scattering experiments were carried out in September-October 2001 and in October 2003 at the iThemba LABS cyclotron facility in South Africa with an incident proton energy of 200 MeV. The obtained data with the energy resolution of triangle E 58 Ni, 89 Y, 90 Zr, 120 Sn, 142 Nd, 166 Er, 208 Pb), thereby establishing the global character of this phenomenon. Fine structure can be described using characteristic energy scales, appearing as a result of the decay of collective modes towards the compound nucleus through a hierarchy of couplings to complex degrees of freedom. For the extraction of the characteristic energy scales from the spectra an entropy index method and a novel technique based on the wavelet analysis are utilized. The global analysis of available data shows the presence of three groups of scales, according to their values. To the first group belong the scales with the values around and below 100 keV, which were detected in all the nuclei studied. The second group contains intermediate scales in the range of 100 keV to 1 MeV. These scales show large variations depending on the nuclear structure of the nucleus. The largest scales above 1 MeV are classified to the third group, describing the global structure of the resonance (the width). The interpretation of the observed scales is realized via the comparison with microscopic model calculations including the coupling of the initial one-particle-one-hole excitations to more complex configurations. A qualitative agreement of the experimentally observed scales with those obtained from the theoretical predictions supports the suggestion of the origin of fine structure from the coupling to the two-particle-two-hole states. However, quantitatively, large deviations are

  19. Magnetic ghosts and monopoles

    International Nuclear Information System (INIS)

    Vandewalle, N; Dorbolo, S

    2014-01-01

    While the physics of equilibrium systems composed of many particles is well known, the interplay between small-scale physics and global properties is still a mystery for athermal systems. Non-trivial patterns and metastable states are often reached in those systems. We explored the various arrangements adopted by magnetic beads along chains and rings. Here, we show that it is possible to create mechanically stable defects in dipole arrangements keeping the memory of dipole frustration. Such defects, nicknamed ‘ghost junctions’, seem to act as macroscopic magnetic monopoles, in a way reminiscent of spin ice systems. (paper)

  20. Magnetic monopoles and baryon decay

    International Nuclear Information System (INIS)

    Pak, N.; Panagiotakopoulos, C.; Shafi, Q.

    1982-08-01

    The scattering of a non-relativistic quark from a GUT monopole is affected by the anomalous magnetic moment of the quark. In order that monopole catalysis of baryon decay can occur, it must be assumed that the anomalous magnetic moment decreases sufficiently rapidly below the QCD scale. (author)

  1. Is there a monopole problem?

    International Nuclear Information System (INIS)

    Dvali, G.; Senjanovic, G.

    1995-07-01

    We show that there exists a range of parameters in SU(5) theory for which the GUT symmetry remains broken at high temperature, thus avoiding the phase transition that gives rise to the overproduction of monopoles. The thermal production of monopoles can be naturally suppressed, keeping their number density below the cosmological limits. (author). 11 refs

  2. Production of magnetic monopole pairs

    International Nuclear Information System (INIS)

    Maher, R.L.

    1980-01-01

    Using a covariant photon propagator (developed by W.B. Campbell) to represent a photon exchange between a magnetic monopole and an electric charge, the first order production amplitudes in a Feynman-Dyson perturbation expansion and the resulting differential cross-sections are calculated for monopole pair creation from: (i) electron positron annihilation, (ii) photon scattering in the presence of a nucleus, and (iii) electron scattering in the presence of a nucleus. This theory does not specify the spin character of magnetic monopoles, so all processes are calculated twice: for spin zero monopoles and for spin one-half monopoles. In the first and last processes the differential cross-sections have sufficiently different dependences on the production angles (associated with the monopoles momenta), so that near threshold experiments could distinguish between whether monopoles are either spin one-half or spin zero entities. For the t'Hooft monopole mass estimate (5-8 x 10 3 GeV) very high energy particle and photon beam sources would be required to achieve threshold for these production processes

  3. (π±, π±' N) reactions on 12C and 208Pb near the giant resonance region

    International Nuclear Information System (INIS)

    Yoo, Sung Hoon.

    1990-05-01

    Angular distributions for the 12 C(π ± , π ± ' p) and 208 Pb(π ± , π ± ' p or n) reactions near the giant resonance region have been measured at T π = 180 MeV, and found different between π + and π - data. This observation is interpreted as evidence for different excitation mechanisms dominating the π - -nucleus and π + -nucleus interactions in the giant resonance region of these targets. A comparison with the single-nucleon knock-out distorted-wave impulse approximation calculations shows, even though these calculations underestimate (π ± , π ± ' N) data for both targets, the dominance of direct process for (π + , π + ' p) or (π - , π - ' n) in contrast to (π - , π - ' p) or (π + , π + ' n). In the (π + , π + ' p) reaction proton-proton hole states are excited directly and appear to have a large probability for direct decay with escape width, whereas in (π - , π - ' p) the preferentially excited neutron-neutron hole doorway states couple to resonance states and decay with spreading width. This interpretation led us to suggest that the ratio of cross-sections for inelastic scattering to the giant resonance region should be written in terms of an incoherent sum of cross-sections to neutron and proton doorway states. In a heavy nucleus such as 208 Pb, neutron and proton doorway states. In a heavy nucleus such as 208 Pb, neutron and proton doorway states contribute incoherently because the different decay processes do not populate the same final states of the residual nucleus

  4. Photoionization of Xe inside C60: Atom-fullerene hybridization, giant cross-section enhancement, and correlation confinement resonances

    International Nuclear Information System (INIS)

    Madjet, Mohamed E.; Renger, Thomas; Hopper, Dale E.; McCune, Matthew A.; Chakraborty, Himadri S.; Rost, Jan-M.; Manson, Steven T.

    2010-01-01

    A theoretical study of the subshell photoionization of the Xe atom endohedrally confined in C 60 is presented. Powerful hybridization of the Xe 5s state with the bottom edge of C 60 π band is found that induces strong structures in the 5s ionization, causing the cross section to differ significantly from earlier results that omit this hybridization. The hybridization also affects the angular distribution asymmetry parameter of Xe 5p ionization near the Cooper minimum. The 5p cross section, on the other hand, is greatly enhanced by borrowing considerable oscillator strength from the C 60 giant plasmon resonance via the atom-fullerene dynamical interchannel coupling. Beyond the C 60 plasmon energy range the atomic subshell cross sections display confinement-induced oscillations in which, over the large 4d shape resonance region, the dominant 4d oscillations induce their ''clones'' in all degenerate weaker channels known as correlation confinement resonances.

  5. Giant Vertebral Notochordal Rest: Magnetic Resonance and Diffusion Weighted Imaging Findings

    International Nuclear Information System (INIS)

    Oner, Ali Yusuf; Akpek, Sergin; Tali, Turgut; Ucar, Murat

    2009-01-01

    A giant vertebral notochordal rest is a newly described, benign entity that is easily confused with a vertebral chordoma. As microscopic notochordal rests are rarely found in adult autopsies, the finding of a macroscopic vertebral lesion is a new entity with only seven previously presented cases. We report here radiological findings, including diffusion weighted images, of a patient with a giant notochordal remnant confined to the L5 vertebra, with an emphasis on its distinction from a chordoma

  6. Monopole scattering with a twist

    International Nuclear Information System (INIS)

    Houghton, C.J.; Sutcliffe, P.M.

    1996-01-01

    By imposing certain combined inversion and rotation symmetries on the rational maps for SU(2) BPS monopoles we construct geodesics in the monopole moduli space. In the moduli space approximation these geodesics describe a novel kind of monopole scattering. During these scattering processes axial symmetry is instantaneously attained and, in some, monopoles with the symmetries of the regular solids are formed. The simplest example corresponds to a charge three monopole invariant under a combined inversion and 90 circle rotation symmetry. In this example three well-separated collinear unit charge monopoles coalesce to form first a tetrahedron, then a torus, then the dual tetrahedron and finally separate again along the same axis of motion. We explicitly construct the spectral curves in this case and use a numerical ADHMN construction to compute the energy density at various times during the motion. We find that the dynamics of the zeros of the Higgs field is extremely rich and we discover a new phenomenon; there exist charge k SU(2) BPS monopoles with more than k zeros of the Higgs field. (orig.)

  7. Dirac's Conception of the Magnetic Monopole, and its Modern Avatars

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 12. Dirac's Conception of the Magnetic Monopole, and its Modern Avatars. Sunil Mukhi. Volume 10 Issue 12 December 2005 pp 193-202. Fulltext. Click here to view fulltext PDF. Permanent link:

  8. Instantons and monopoles

    International Nuclear Information System (INIS)

    Tyurin, N A

    2002-01-01

    In this survey we present the main notions and constructions of gauge theories, namely, the Donaldson theory, the Seiberg-Witten theory, and the theory of B-monopoles, which connects the previous two theories. In the framework of differential geometry these theories give new invariants of smooth structures in dimension 4. The introduction of these new gauge invariants has helped to solve many problems of modern geometry. The apparatus developed in the framework of these theories leads to new modern methods of investigation both in smooth geometry and in applied problems of mathematical physics. Without striving for the greatest possible generality, the survey aims to present the topic in maximal breadth and accessibility

  9. Heavy ion coulomb excitation and gamma decay studies of the one and two phonon giant dipole resonances in 208Pb and 209Bi

    International Nuclear Information System (INIS)

    Mueller, P.E.; Beene, J.R.; Bertrand, F.E.; Halbert, M.L.; Olive, D.H.; Varner, R.L.; Sherrill, B.; Thoennessen, M.; Lautridou, P.; Lefevre, F.; Marques, M.; Matulewicz, T.; Mittig, W.; Ostendorf, R.; Roussel-Chomaz, P.; Schutz, Y.; Pol, J. van; Wilschut, H.W.; Diaz, J.; Ferrero, J.L.; Marin, A.

    1994-01-01

    Projectile - phonon coincidences were measured for the scattering of an 80 MeV/nucleon 64 Zn beam from 208 Pb and 209 Bi targets at the GANIL heavy ion accelerator facility. Projectile-like particles between 0.5 and 4.5 relative to the incident beam direction were detected in the SPEG energy loss spectrometer where their momentum, charge, and mass were determined. Photons were detected in the BaF 2 scintillation detector array TAPS. Light charged particles produced in the reaction were detected in the KVI Forward Wall. The analysis of the data acquired in this experiment is focused on three different phenomena: (1) the two phonon giant dipole resonance, (2) time dependence of the decay of the one phonon giant dipole resonance, and (3) giant resonance strength in projectile nuclei. (orig.)

  10. A SECOND GIANT PLANET IN 3:2 MEAN-MOTION RESONANCE IN THE HD 204313 SYSTEM

    International Nuclear Information System (INIS)

    Robertson, Paul; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Brugamyer, Erik J.; Barnes, Stuart I.; Caldwell, Caroline; Horner, J.; Wittenmyer, Robert A.; Simon, Attila E.

    2012-01-01

    We present eight years of high-precision radial velocity (RV) data for HD 204313 from the 2.7 m Harlan J. Smith Telescope at McDonald Observatory. The star is known to have a giant planet (Msin i = 3.5 M J ) on a ∼1900 day orbit, and a Neptune-mass planet at 0.2 AU. Using our own data in combination with the published CORALIE RVs of Ségransan et al., we discover an outer Jovian (Msin i = 1.6 M J ) planet with P ∼ 2800 days. Our orbital fit suggests that the planets are in a 3:2 mean motion resonance, which would potentially affect their stability. We perform a detailed stability analysis and verify that the planets must be in resonance.

  11. Using Schumann Resonance Measurements for Constraining the Water Abundance on the Giant Planets - Implications for the Solar System Formation

    Science.gov (United States)

    Simoes, Fernando; Pfaff, Robert; Hamelin, Michel; Klenzing, Jeffrey; Freudenreich, Henry; Beghin, Christian; Berthelier, Jean-Jacques; Bromund, Kenneth; Grard, Rejean; Lebreton, Jean-Pierre; hide

    2012-01-01

    The formation and evolution of the Solar System is closely related to the abundance of volatiles, namely water, ammonia, and methane in the protoplanetary disk. Accurate measurement of volatiles in the Solar System is therefore important to understand not only the nebular hypothesis and origin of life but also planetary cosmogony as a whole. In this work, we propose a new, remote sensing technique to infer the outer planets water content by measuring Tremendously and Extremely Low Frequency (TLF-ELF) electromagnetic wave characteristics (Schumann resonances) excited by lightning in their gaseous envelopes. Schumann resonance detection can be potentially used for constraining the uncertainty of volatiles of the giant planets, mainly Uranus and Neptune, because such TLF-ELF wave signatures are closely related to the electric conductivity profile and water content.

  12. USING SCHUMANN RESONANCE MEASUREMENTS FOR CONSTRAINING THE WATER ABUNDANCE ON THE GIANT PLANETS—IMPLICATIONS FOR THE SOLAR SYSTEM'S FORMATION

    International Nuclear Information System (INIS)

    Simões, Fernando; Pfaff, Robert; Klenzing, Jeffrey; Freudenreich, Henry; Bromund, Kenneth; Martin, Steven; Rowland, Douglas; Hamelin, Michel; Berthelier, Jean-Jacques; Béghin, Christian; Lebreton, Jean-Pierre; Grard, Rejean; Sentman, Davis; Takahashi, Yukihiro; Yair, Yoav

    2012-01-01

    The formation and evolution of the solar system is closely related to the abundance of volatiles, namely water, ammonia, and methane in the protoplanetary disk. Accurate measurement of volatiles in the solar system is therefore important for understanding not only the nebular hypothesis and origin of life but also planetary cosmogony as a whole. In this work, we propose a new remote sensing technique to infer the outer planets' water content by measuring Tremendously and Extremely Low Frequency (TLF-ELF) electromagnetic wave characteristics (Schumann resonances) excited by lightning in their gaseous envelopes. Schumann resonance detection can be potentially used for constraining the uncertainty of volatiles of the giant planets, mainly Uranus and Neptune, because such TLF-ELF wave signatures are closely related to the electric conductivity profile and water content.

  13. Empty-electronic-state evolution for Sc and electron dynamics at the 3p-3d giant dipole resonance

    International Nuclear Information System (INIS)

    Hu, Y.; Wagener, T.J.; Gao, Y.; Weaver, J.H.

    1989-01-01

    Inverse photoemission has been used to study the developing electronic states of an early transition metal, Sc, during thin-film growth and to investigate the effects of these states on the 3p-3d giant dipole resonance. Energy- and coverage-dependent intensity variations of the empty Sc states show that the 3d maximum moves 1.1 eV toward the Fermi level as the thickness of the Sc film increases from 1 to 300 A as measured with an incident electron energy of 41.25 eV, an effect attributed to metallic band formation via hybridization of atomic 4s and 3d states. Incident-energy-dependent intensity variations for these empty Sc features show resonant photon emission for incident electron energies above the 3p threshold, with maxima at 43 and 44 eV for 300- and 5-A-thick films, respectively. Considerations of hybridization-induced energy shifts of the empty Sc 3d states demonstrate that the radiative energy changes very little with Sc coverages. These studies indicate coupling of decay channels involving the inverse photoemission continuum and the recombination of the atomic 3p-3d giant dipole transition, the energy of the latter being determined by atomic 3p-3d excitation processes

  14. Yang Monopoles and Emergent Three-Dimensional Topological Defects in Interacting Bosons

    Science.gov (United States)

    Yan, Yangqian; Zhou, Qi

    2018-06-01

    The Yang monopole as a zero-dimensional topological defect has been well established in multiple fields in physics. However, it remains an intriguing question to understand the interaction effects on Yang monopoles. Here, we show that the collective motion of many interacting bosons gives rise to exotic topological defects that are distinct from Yang monopoles seen by a single particle. Whereas interactions may distribute Yang monopoles in the parameter space or glue them to a single giant one of multiple charges, three-dimensional topological defects also arise from continuous manifolds of degenerate many-body eigenstates. Their projections in lower dimensions lead to knotted nodal lines and nodal rings. Our results suggest that ultracold bosonic atoms can be used to create emergent topological defects and directly measure topological invariants that are not easy to access in solids.

  15. Study of quadrupolar transitions by 108.5 MeV 3He inelastic scattering at small angles. Anomalous behaviour of giant quadrupole resonance

    International Nuclear Information System (INIS)

    Bouhelal, O.K.

    1982-07-01

    Giant resonances have been studied through the inelastic scattering of 108.5 MeV 3 He on several nuclei. At the very small angles (theta 0 ), the quadrupole giant resonance experimental cross-section is about twice the value predicted by DWBA calculations based on a collective model. The comparison of the experimental data and the theoretical data calculations confirms the validity of DWBA for the first excited state of low energy and same multipolarity L = 2 at the very small angles. The angular distribution for L = 0 transition of energy close to that of the quadrupole giant resonance reaches its maximum at 0 0 . The presence of an L = 0 component permits to describe the shape of the quadrupole giant resonance angular distribution, but difficulties are encountered when applying the sum rule for the heavy nuclei. Better agreement with the experimental angular distribution at small angles is obtained if a semimicroscopic convolution model of the quadrupole resonance is assumed. For excited states of low energy and multipolarity L not equal to 2, the results from the convolution model are as good as those from the standard collective model. The 2 + state in heavy nuclei is, however, much better described by the collective model [fr

  16. Illustrated cosmic monopole

    CERN Document Server

    Seagrave, Wyken

    2015-01-01

    Truly bizarre, utterly unique I've never read a novel quite like this before. The author takes you on an exciting adventure full of unforgettable and vivid imagery. Solidly written with each character's personality shining through. If you find physics fascinating you will not be disappointed by the author's keen intellect and clear understanding of this most challenging (for me anyway) scientific subject. This is not a novel I will forget anytime soon, I would highly recommend it. Andrewly Very imaginative tale Anybody interested in a very imaginative and engrossing sci fi story needs to check this one out. I have been reading sci fi for decades and this story has elements that surprise me which is very unusual considering the number of novels and stories I have over the years. ric freeman Summary of the story The cosmic monopole has been wandering the Universe since it was created in the Big Bang. Its existence is fundamental to the way the Universe works. It is finally trapped by the powerful magnetic f...

  17. Monopole current dynamics and color confinement

    International Nuclear Information System (INIS)

    Ichie, H.; Suganuma, H.; Tanaka, A.

    1998-01-01

    Color confinement can be understood by the dual Higgs theory, where monopole condensation leads to the exclusion of the electric flux from the QCD vacuum. We study the role of the monopole for color confinement by investigating the monopole current system. When the self-energy of the monopole current is small enough, long and complicated monopole world-lines appear, which is a signal of monopole condensation. In the dense monopole system, the Wilson loop obeys the area-law, and the string tension and the monopole density have similar behavior as the function of the self-energy, which seems that monopole condensation leads to color confinement. On the long-distance physics, the monopole current system almost reproduces essential features of confinement properties in lattice QCD. In the short-distance physics, however, the monopole-current theory would become nonlocal and complicated due to the monopole size effect. This monopole size would provide a critical scale of QCD in terms of the dual Higgs mechanism. (orig.)

  18. Magnetic monopoles in Kaluza Klein theory

    International Nuclear Information System (INIS)

    Sundaresan, M.K.; Tanaka, K.

    1985-01-01

    We start with an introduction to magnetic monopoles and then discuss the magnetic monopoles in 5-dimensions, the stability of solution with respect to small changes in the metric, and finally end with remarks

  19. Magnetic monopoles in particle physics and cosmology

    International Nuclear Information System (INIS)

    Preskill, J.

    1986-01-01

    Hardly any topic better illustrates the connection between particle physics and cosmology than the topic of magnetic monopoles. While there is no persuasive evidence that a monopole has ever been detected, the existence of monopoles is implied by deeply cherished beliefs about the structure of matter at extremely short distances. And the fact that monopoles are so rare as to have escaped detection has profound implications concerning the very early history of the universe. This article gives a brief overview of the theory of magnetic monopoles and its relevance to cosmology. In Section II, the author explains the connection between monopoles and the unification of the fundamental interactions. In Section III, he describes how monopoles might have been produced in the very early universe. Theoretical limits on the abundance of monopoles derived from astrophysical considerations are the subject of Section IV. Section V contains conclusions

  20. Primordial inflation and the monopole problem

    International Nuclear Information System (INIS)

    Olive, K.A.; Seckel, D.

    1984-01-01

    This chapter discusses the cosmological abundance of magnetic monopoles in locally supersymmetry grand unified theories (GUTs) and primordial inflation. It is shown how the magnetic monopole problem can be solved in variants of broken N=1 supergravity primordial inflation. The monopole problem and its solution in inflationary models is reviewed. It is demonstrated that the monopole problem can be solved by coupling primordial inflation to supersymmetric SU(5) breaking

  1. On charge-3 cyclic monopoles

    International Nuclear Information System (INIS)

    Braden, H W; D'Avanzo, Antonella; Enolski, V Z

    2011-01-01

    We determine the spectral curve of charge-3 BPS su(2) monopoles with C 3 cyclic symmetry. The symmetry means that the genus 4 spectral curve covers a (Toda) spectral curve of genus 2. A well adapted homology basis is presented enabling the theta functions and monopole data of the genus 4 curve to be given in terms of genus 2 data. The Richelot correspondence, a generalization of the arithmetic mean, is used to solve for this genus 2 curve. Results of other approaches are compared

  2. Proton capture by magnetic monopoles

    International Nuclear Information System (INIS)

    Olaussen, K.; Olsen, H.A.; Oeverboe, I.; Osland, P.

    1983-09-01

    In the Kazama-Yang approximation, the lowest monopole-proton bound states have binding energies of 938 MeV, 263 keV, 105 eV, and 0.04 eV. The cross section for radiative capture to these states is for velocities β = 10 -5 - 10 -3 found to be of the order of 10 -28 - 10 -26 cm 2 . For the state that has a binding energy of 263 keV, the capture length in water is 171 x (β/10 -4 )sup(0.48) m. Observation of photons from the capture process would indicate the presence of monopoles. (orig.)

  3. Extended monopoles in gauge field theories

    International Nuclear Information System (INIS)

    Horvath, Z.; Palla, L.

    1977-04-01

    The paper gives a review of the 't Hooft monopole and briefly discusses the general topological considerations connected with monopoles. A method is presented for constructing explicit monopole solutions in any gauge theory. Some stability questions and time-dependent problems are also considered

  4. Cosmological production of Kaluza-Klein monopoles

    International Nuclear Information System (INIS)

    Harvey, J.A.; Kolb, E.W.; Perry, M.J.

    1984-09-01

    The cosmological production of Kaluza-Klein monopoles is discussed. The present monopole to entropy ratio is calculated in some simple models with the conclusion that this ratio is unacceptably large unless additional mechanisms for entropy production or monopole annihilation are present

  5. Monopole track characteristics in plastic detectors

    Science.gov (United States)

    Ahlen, S. P.

    1975-01-01

    Total and restricted energy loss rates were calculated for magnetic monopoles of charge g = 137 e in Lexan polycarbonate. Range-energy curves are also presented. The restricted energy loss model is used to estimate the appearance of a monopole track in plastic detectors. These results should be useful for the design and analysis of monopole experiments.

  6. Photon nuclear scattering on lead and bismuth in the region of the giant resonance

    International Nuclear Information System (INIS)

    Tamas, Gabriel.

    1976-01-01

    The results of monochromatic photon nuclear scattering studies on natural lead and bismuth targets are presented. The cross sections for the inelastic scattering leading to the first excited levels of 204 Pb, 206 Pb and 207 Pb are important, in agreement with theoretical predictions. The elastic scattering amplitude is related to the total photon absorption by dispersion relations. It is then possible to determine the spin of resonances excited by the reaction studied. Precise measurements carried out between 14 and 20MeV revealed that the angular distribution cannot be explained by a single dipolar resonance. A quadrupolar resonance at E 2 =14MeV must be introduced [fr

  7. Excitation of giant resonances in 20Ne + 90Zr and 208Pb inelastic scattering at 40 MeV/u1

    International Nuclear Information System (INIS)

    Suomijaervi, T.; Beaumel, D.; Blumenfeld, Y.; Chomaz, P.; Frascaria, N.; Garron, J.P.; Jacmart, J.C.; Roynette, J.C.; Kraus, L.; Link, I.

    1988-01-01

    The giant resonance region in the inelastic spectra from the reactions 20 Ne + 90 Zr and 20 Ne + 208 Pb at 40 MeV/nucleon has been studied with a good energy and angular resolutions. The strength distributions of the different multipolarities contributing to the cross section were obtained by a resonance shape independent analysis. In the case of 208 Pb the GDR strength was found to be strongly shifted towards lower excitation energies which can be explained by the exponentially decreasing Coulomb excitation probability. Furthermore, indications for a high multipolarity component in the resonance structure were found in both reactions

  8. Monopole-track characteristics in plastic detectors

    Science.gov (United States)

    Ahlen, S. P.

    1976-01-01

    Total and restricted energy loss rates are calculated for magnetic monopoles of charge g = 137 e in Lexan polycarbonate. Range-energy curves are also presented. The restricted-energy-loss model is used to estimate the appearance of a monopole track in plastic detectors. The results are applied to the event observed by Price et al. and identified by them as a monopole. It is found that the observed etch rate is consistent with what one would expect for a slow magnetic monopole. These results should also be of use to other investigators for both the design and analysis of monopole experiments.

  9. Monopole-antimonopole interaction potential

    Science.gov (United States)

    Saurabh, Ayush; Vachaspati, Tanmay

    2017-11-01

    We numerically study the interactions of twisted monopole-antimonopole pairs in the 't Hooft-Polyakov model for a range of values of the scalar to vector mass ratio. We also recover the sphaleron solution at maximum twist discovered by Taubes [Commun. Math. Phys. 86, 257 (1982), 10.1007/BF01206014] and map out its energy and size as functions of parameters.

  10. Excitation of the giant quadrupole resonance in /sup 58/Ni with /sup 20/Ne

    CERN Document Server

    Bohlen, H G; Ingold, G; Lettau, H; Ossenbrink, H; von Oertzen, W

    1981-01-01

    The heavy-ion induced excitation of the quadrupole resonance in /sup 58/Ni has been studied with /sup 20/Ne beams of 14.5 and 19.6 MeV/N incident energy. The broad resonance structure is clearly observed; the strength exhausts 44% and 60% of the energy weighted sum rule (EWSR) at the two incident energies, respectively. The background is partly explained by a three-body reaction mechanism, which is based on the one-nucleon pick-up reaction into unbound states followed by one- nucleon emission. The remaining part is interpreted as inelastic excitation of other multipoles. (11 refs).

  11. Calculations of the giant-dipole-resonance photoneutrons using a coupled EGS4-morse code

    International Nuclear Information System (INIS)

    Liu, J.C.; Nelson, W.R.; Kase, K.R.; Mao, X.S.

    1995-10-01

    The production and transport of the photoneutrons from the giant-dipoleresonance reaction have been implemented in a coupled EGS4-MORSE code. The total neutron yield (including both the direct neutron and evaporation neutron components) is calculated by folding the photoneutron yield cross sections with the photon track length distribution in the target. Empirical algorithms based on the measurements have been developed to estimate the fraction and energy of the direct neutron component for each photon. The statistical theory in the EVAP4 code, incorporated as a MORSE subroutine, is used to determine the energies of the evaporation neutrons. These represent major improvements over other calculations that assumed no direct neutrons, a constant fraction of direct neutrons, monoenergetic direct neutron, or a constant nuclear temperature for the evaporation neutrons. It was also assumed that the slow neutrons ( 2 θ, which have a peak emission at 900. Comparisons between the calculated and the measured photoneutron results (spectra of the direct, evaporation and total neutrons; nuclear temperatures; direct neutron fractions) for materials of lead, tungsten, tantalum and copper have been made. The results show that the empirical algorithms, albeit simple, can produce reasonable results over the interested photon energy range

  12. Excitation of the giant resonance in the radiative pion capture on lp shell nuclei

    International Nuclear Information System (INIS)

    Dogotar', G.E.

    1978-01-01

    The spin-dipole transitions in the (π - ,γ) reaction on 6 Li, 7 Li, 9 Be, 13 C and 14 N are calculated in the framework of shell model and are compared with experiment. The discussion includes the gross structure and the quantum numbers of the resonance, relative branchings, prominent partial transitions and total yields. General findings is that the calculated (π - ,γ) yield distributions describe the data well in those cases where also the photonuclear data are well reproduced, although the amplitudes of the elementary processes are different. In the case considered, the best agreement is obtained for A=9 and 14. The configurational splitting of the resonances is clearly seen in the A=6 and 7 cases, to somewhat less extent also for A=9. For heavier nuclei the contribution from hole excitation is small and is spread out. For A=7 and 11 the calculated main peaks are at too low intrinsic excitation energies as compared with histograms

  13. The importance of the giant resonances in hadron and muon induced fission

    International Nuclear Information System (INIS)

    Hartfiel, J.

    1985-01-01

    In the first part of the thesis the fission probability of 238 U by means of the reaction 238 U(α,α'f) is studied at an incident energy of 480 MeV and a scattering angle of 3.4 0 . In the measured spectrum of the inelastically scattered α particles a strong resonance is found in the excitation energy range from 8 to 13 MeV. The center of mass of the resonance lies at 11 MeV. Its width extends to 4.5 MeV. In the second part of the thesis the muon induced fission of 235 U, 238 U, 237 Np, 242 Pu, and 244 Pu is studied. Thereby both fission fragments are detected in coincidence by two surface barrier detectors. By this it is possible for the first time to measure the mass and kinetic energy distribution of the fission fragments. (orig./HSI) [de

  14. Development and test of the e+e- pair spectrometer for the detection of the electromagnetic decay of the E0 giant resonance state

    International Nuclear Information System (INIS)

    Katayama, I.; Fujita, Y.; Fujiwara, M.; Morinobu, S.; Ikegami, H.

    1978-01-01

    A lens type pair spectrometer of electron and positron has been developed and tested in order to detect the electromagnetic decay (pair creation) of the E0 giant resonance state. It was found from the one day machine time test (targets: natural Mo and Pb, beam:α, 70 MeV) that the improvement of the apparatus is necessary for getting a definite information on the yield of high energy electron pairs. (author)

  15. Rational maps, monopoles and skyrmions

    International Nuclear Information System (INIS)

    Houghton, C.J.; Manton, N.S.

    1998-01-01

    We discuss the similarities between BPS monopoles and skyrmions, and point to an underlying connection in terms of rational maps between Riemann spheres. This involves the introduction of a new ansatz for Skyrme fields. We use this to construct good approximations to several known skyrmions, including all the minimal energy configurations up to baryon number nine, and some new solutions such as a baryon number seventeen Skyrme field with the truncated icosahedron structure of a buckyball. The new approach is also used to understand the low-lying vibrational modes of skyrmions, which are required for quantization. Along the way we discover an interesting Morse function on the space of rational maps which may be of use in understanding the Sen forms on the monopole moduli spaces. (orig.)

  16. The search for magnetic monopoles

    International Nuclear Information System (INIS)

    Barish, B.C.

    1983-01-01

    In this review, I discuss the status and prospects for experimental studies aimed at the detection of Grand Unified Monopoles. The only positive evidence, at this time, remains the one observed candidate of Cabrera. The relations of this observation to the expected abundance in cosmic rays and to limits from other detection techniques are discussed. Lastly, prospects for future studies with sensitivity to much smaller fluxes are also presented

  17. Self-consistent treatment of nuclear collective motion with an application to the giant-dipole resonance

    International Nuclear Information System (INIS)

    Liran, S.; Technion-Israel Inst. of Tech., Haifa. Dept. of Physics)

    1977-01-01

    This paper extends the recent theory of Liran, Scheefer, Scheid and Greiner on non-adiabatic cranking and nuclear collective motion. In the present work we show the self-consistency conditions for the collective motion, which are indicated by appropriate time-dependent Lagrange multipliers, can be treated explicitly. The energy conservation and the self-consistency condition in the case of one collective degree of freedom are expressed in differential form. This leads to a set of coupled differential equations in time for the many-body wave function, for the collective variable and for the Lagrange multiplier. An iteration procedure similar to that of the previous work is also presented. As an illustrative example, we investigate Brink's single-particle description of the giant-dipole resonance. In this case, the important role played by non-adiabaticity and self-consistency in determining the collective motion is demonstrated and discussed. We also consider the fact that in this example of a fast collective motion, the adiabatic cranking model of Inglis gives the correct mass parameter. (orig.) [de

  18. Improvement of photoneutron spectrum measurement produced by bombardment of 2 GeV electrons above giant dipole resonance region

    International Nuclear Information System (INIS)

    Lee, H. S.; Park, J. S.; Choi, H. D.; Sato, Tatsuhiko; Shin, Kasuo; Ban, Syuichi

    2000-01-01

    Above the Giant Dipole Resonance (GDR) region, high energy photoneutron spectra produced by irradiation of 2.04 GeV electrons into Pb target were measured by Time-of-Flight (TOF) technique. The differential photoneutron yields were obtained at a fixed angle of 90 degrees to the electron beam direction. The TOF system consists of Pilot-U plastic scintillation detector, which has fast response time, and the high speed multiscaler or CAMAC TDC. In the improvement of experimental setup to extend the flight distance to 10.4 m lead to make the measurable energy to 500 MeV from 300 MeV. And using the TDC based electronics lead to use a veto counter. The results were compared with the calculated one by using EGS4 and Modified PICA95. The characteristics of this TOF system was introduced in this paper and the results for several measuring conditions, which are flight distance, TOF electronics, and type of neutron detector, were discussed to improve the accuracy of this measurement

  19. Solid state deuterium nuclear magnetic resonance detection of transmembrane-potential-driven tetraphenylphosphonium redistribution across Giant Unilamellar Vesicle bilayers

    International Nuclear Information System (INIS)

    Franzin, Carla Maria Mirella

    1995-01-01

    It has been demonstrated that deuterium nuclear magnetic resonance ( 2 H NMR) of Giant Unilamellar Vesicles (GUVs) consisting of specifically choline-deuterated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), plus 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) and cholesterol can be used to monitor the transbilayer redistribution of tetraphenylphosphonium (TPP + ) in response to a transmembrane potential (δψ tm ). The 2 H quadrupolar splittings (δν Q 's) measured reflect the level of TPP + bound at the membrane surface due to the latter's effect on the membrane surface electrostatic potential, ψ s . Results reveal the appearance of two distinct δν Q 's, due to differences in bound TPP + at the inner versus the outer monolayer in response to a δψ tm . The observed values of the δν Q 's agree with theoretical predictions based on a derived mathematical model that takes into account δψ tm , plus ψ s , plus the equilibrium binding of TPP + from solution onto the membrane surface, plus the sensitivity of δν Q to the amount of bound TPP + . This model identifies experimental factors that lead to improvements in spectral resolution. Henceforth, 2 H NMR is a valuable tool for quantifying transmembrane asymmetries of ψ s . (author)

  20. Giant resonance spectroscopy of 40Ca with the (e,e'x) reaction (III): Direct versus statistical decay

    International Nuclear Information System (INIS)

    Carter, J.; Diesener, H.; Helm, U.; Herbert, G.; Neumann-Cosel, P. von; Richter, A.; Schrieder, G.; Strauch, S.

    2001-01-01

    The present article is the third out of three on a study of the 40 Ca(e,e'x) reaction discussing the role of direct and statistical contributions to the decay of the observed giant resonance strengths. The proton and α decay modes leading to low-lying final states in 36 Ar and 39 K were investigated. The branching ratios for the p 0 , p 123 , α 0 and α 1 channels are compared to statistical model calculations. In the excitation region of dominant isoscalar E2 strength (E x =12-18 MeV) good agreement is observed. Model predictions of direct E2 decay for the (α 0 +α 1 )/(p 0 +p 1 ) ratio describe the data poorly. In the isovector E1 excitation region large excess strength is found in the population of low-lying states in 39 K. A fluctuation analysis shows the direct contributions to the p 0 , p 1 channels to be ≥85%. The presence of preequilibrium components is indicated by the significant nonstatistical decay to the p 3 level which has a dominant 'phonon·hole' structure. Cross correlations reveal no significant branching between the different channels. The correlations between different electron scattering angles in the p 0 , p 1 and p 3 decay result in an interaction radius compatible with the whole nucleus acting as an emitting source

  1. Isomeric ratios in photonuclear reactions of molybdenum isotopes induced by bremsstrahlung in the giant dipole resonance region

    International Nuclear Information System (INIS)

    Tran Duc Thiep; Truong Thi An; Phan Viet Cuong; Nguyen The Vinh; Bui Minh Hue; Belov, A.G.; Maslov, O.D.; Mishinsky, G.V.; Zhemenik, V.I.

    2017-01-01

    We have determined the isomeric ratios of isomeric pairs "9"7"m","gNb, "9"5"m","gNb and "9"1"m","gMo produced in "9"8Mo(γ, p)"9"7"m","gNb, "9"6Mo(γ, p)"9"5"m","gNb and "9"2Mo(γ, n)"9"1"m","gMo photonuclear reactions in the giant dipole resonance (GDR) region by the activation method. The results were analyzed, discussed and compared with the similar data from literature to examine the role of excitation energy, neutron configuration, channel effect, and direct and pre-equilibrium processes in (γ, p) photonuclear reactions. In this work the isomeric ratios for "9"7"m","gNb from 14 to 19 MeV, for "1"9"5"m","gNb from 14 to 24 MeV except 20 and 23.5 MeV and for "9"1"m","gMo at 14 and 15 MeV were first measured.

  2. A Direct Search for Dirac Magnetic Monopoles

    Energy Technology Data Exchange (ETDEWEB)

    Mulhearn, Michael James [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2004-10-01

    Magnetic monopoles are highly ionizing and curve in the direction of the magnetic field. A new dedicated magnetic monopole trigger at CDF, which requires large light pulses in the scintillators of the time-of-flight system, remains highly efficient to monopoles while consuming a tiny fraction of the available trigger bandwidth. A specialized offline reconstruction checks the central drift chamber for large dE/dx tracks which do not curve in the plane perpendicular to the magnetic field. We observed zero monopole candidate events in 35.7 pb-1 of proton-antiproton collisions at √s = 1.96 TeV. This implies a monopole production cross section limit σ < 0.2 pb for monopoles with mass between 100 and 700 GeV, and, for a Drell-Yan like pair production mechanism, a mass limit m > 360 GeV.

  3. Electroweak monopoles and the electroweak phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Arunasalam, Suntharan; Kobakhidze, Archil [The University of Sydney, ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, Sydney, NSW (Australia)

    2017-07-15

    We consider an isolated electroweak monopole solution within the Standard Model with a nonlinear Born-Infeld extension of the hypercharge gauge field. Monopole (and dyon) solutions in such an extension are regular and their masses are predicted to be proportional to the Born-Infeld mass parameter. We argue that cosmological production of electroweak monopoles may delay the electroweak phase transition and make it more strongly first order for monopole masses M >or similar 9.3 . 10{sup 3} TeV, while the nucleosynthesis constraints on the abundance of relic monopoles impose the bound M monopoles with a mass in this shallow range may be responsible for the dynamical generation of the matter-antimatter asymmetry during the electroweak phase transition. (orig.)

  4. Comment on 'Angular momentum gated giant dipole resonance measurements in the reaction 28Si+58Ni at E(28Si)=100 and 125 MeV'

    International Nuclear Information System (INIS)

    Heckman, P.; Thoennessen, M.

    2003-01-01

    In a recent paper, the giant dipole resonance width was studied as a function of angular momentum in the nucleus 86 Mo. The width of the resonance was found to be constant over a spin range of (0-40)(ℎ/2π). It was concluded that the angular momentum dependence for 86 Mo differs from that of Sn isotopes. We compared both datasets with a phenomenological formula based on the thermal fluctuation theory. The 86 Mo data are inconsistent with the formula in contrast to the previously analyzed Sn data, which seems to indicate that the angular momentum dependence of the phenomenological model is not universally applicable

  5. Giant intracranial aneurysms; Magnetic resonance imaging follow-up and clinical symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Kondoh, Takeshi; Fujita, Katsuzo; Tamaki, Norihiko; Matsumoto, Satoshi [Kobe Univ. (Japan). School of Medicine; Yamashita, Haruo; Shirakata, Masaya

    1991-06-01

    Twenty-four intracranial aneurysms over 20 mm in diameter were studied with magnetic resonance (MR) imaging. MR imaging follow-up of eight cases revealed induced thrombus with homogeneous intensity and decreased size even after complete intraluminal thrombosis. Most cases demonstrated homogeneous intensity thrombus in contrast to the heterogeneous intensity of spontaneous thrombus. The clinical symptoms could not be explained retrospectively by the thrombus characteristics. Perianeurysmal high intensity, indicating cerebral edema, was detected in one case presenting with a rapid increase in size. MR imaging is useful for following these pathological intra- and perianeurysmal changes. (author).

  6. Magnetic monopoles in field theory and cosmology.

    Science.gov (United States)

    Rajantie, Arttu

    2012-12-28

    The existence of magnetic monopoles is predicted by many theories of particle physics beyond the standard model. However, in spite of extensive searches, there is no experimental or observational sign of them. I review the role of magnetic monopoles in quantum field theory and discuss their implications for particle physics and cosmology. I also highlight their differences and similarities with monopoles found in frustrated magnetic systems.

  7. Correlations between Abelian monopoles and center vortices

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini Nejad, Seyed Mohsen, E-mail: smhosseininejad@ut.ac.ir; Deldar, Sedigheh, E-mail: sdeldar@ut.ac.ir

    2017-04-15

    We study the correlations between center vortices and Abelian monopoles for SU(3) gauge group. Combining fractional fluxes of monopoles, center vortex fluxes are constructed in the thick center vortex model. Calculating the potentials induced by fractional fluxes constructing the center vortex flux in a thick center vortex-like model and comparing with the potential induced by center vortices, we observe an attraction between fractional fluxes of monopoles constructing the center vortex flux. We conclude that the center vortex flux is stable, as expected. In addition, we show that adding a contribution of the monopole-antimonopole pairs in the potentials induced by center vortices ruins the Casimir scaling at intermediate regime.

  8. Global monopoles can change Universe's topology

    International Nuclear Information System (INIS)

    Marunović, Anja; Prokopec, Tomislav

    2016-01-01

    If the Universe undergoes a phase transition, at which global monopoles are created or destroyed, topology of its spatial sections can change. More specifically, by making use of Myers' theorem, we show that, after a transition in which global monopoles form, spatial sections of a spatially flat, infinite Universe becomes finite and closed. This implies that global monopoles can change the topology of Universe's spatial sections (from infinite and open to finite and closed). Global monopoles cannot alter the topology of the space-time manifold.

  9. Monopoles and quark confinement: Introduction and overview

    International Nuclear Information System (INIS)

    Yee, Ken.

    1994-01-01

    We (try to) pedagogically explain how monopoles arise in QCD, why maximal Abelian (MA) gauge is ''special'' for monopole study, the Abelian projection in MA gauge, its resultant degrees of freedom (photons, monopoles and charged matter fields), and the QCD-equivalent action in terms of these degrees of freedom. Then we turn to more recent developments in the subject: Abelian dominance, large N behavior of Abelian projected QCD, mass of the charged matter fields, notion of an effective photon-monopole action obtained by integrating out the charged matter fields, and problems encountered in evaluating this effective action using the microcanonical demon method on the lattice

  10. The Axially Symmetric One-Monopole

    International Nuclear Information System (INIS)

    Wong, K.-M.; Teh, Rosy

    2009-01-01

    We present new classical generalized one-monopole solution of the SU(2) Yang-Mills-Higgs theory with the Higgs field in the adjoint representation. We show that this solution with θ-winding number m = 1 and φ-winding number n = 1 is an axially symmetric generalization of the 't Hooft-Polyakov one-monopole. We construct this axially symmetric one-monopole solution by generalizing the large distance asymptotic solutions of the 't Hooft-Polyakov one-monopole to the Jacobi elliptic functions and solving the second order equations of motion numerically when the Higgs potential is vanishing. This solution is a non-BPS solution.

  11. QPM Analysis of 205Tl Nuclear Excitations below the Giant Dipole Resonance

    Science.gov (United States)

    Benouaret, N.; Beller, J.; Isaak, J.; Kelley, J. H.; Pai, H.; Pietralla, N.; Ponomarev, V. Yu.; Raut, R.; Romig, C.; Rusev, G.; Savran, D.; Scheck, M.; Schnorrenberger, L.; Sonnabend, K.; Tonchev, A. P.; Tornow, W.; Weller, H. R.; Zweidinger, M.

    2015-05-01

    We analysed our experimental recent findings of the dipole response of the odd-mass stable nucleus 205Tl within the quasi-particle phonon model. Using the phonon basis constructed for the neighbouring 204Hg and wave function configurations for 205Tl consisting of a mixture of quasiparticle ⊗ N-phonon configurations (N=0,1,2), only one group of fragmented dipole excited states has been reproduced at 5.5 MeV in comparison to the experimental distribution which shows a second group at about 5 MeV. The computed dipole transition strengths are mainly of E1 character which could be associated to the pygmy dipole resonance.

  12. QPM Analysis of 205Tl Nuclear Excitations below the Giant Dipole Resonance

    Directory of Open Access Journals (Sweden)

    Benouaret N.

    2015-01-01

    Full Text Available We analysed our experimental recent findings of the dipole response of the odd-mass stable nucleus 205Tl within the quasi-particle phonon model. Using the phonon basis constructed for the neighbouring 204Hg and wave function configurations for 205Tl consisting of a mixture of quasiparticle ⊗ N-phonon configurations (N=0,1,2, only one group of fragmented dipole excited states has been reproduced at 5.5 MeV in comparison to the experimental distribution which shows a second group at about 5 MeV. The computed dipole transition strengths are mainly of E1 character which could be associated to the pygmy dipole resonance.

  13. Ultra-Wideband Coplanar-Fed Monopoles: A Comparative Study

    Directory of Open Access Journals (Sweden)

    J. Jilkova

    2008-04-01

    Full Text Available The paper provides an experimental comparison of four types of ultra-wideband coplanar-fed planar monopole antennas. Parameters of the open stub completed by an L-shaped monopole and the cross monopole were adopted from the literature. The forked monopole and the coplanar monopole were fabricated and measured. Monopoles were compared from the viewpoint of the impedance bandwidth, gain, directivity patterns and dimensions.

  14. Properties of Hot and Fast Rotating Atomic Nuclei Studied by Means of Giant Dipole Resonance in Exclusive Experiments

    International Nuclear Information System (INIS)

    Maj, A.

    2000-01-01

    This work entitled ''Properties of hot and fast rotating atomic nuclei studied by means of Giant Dipole Resonance in exclusive experiments'', is the habilitation thesis of dr. Adam Maj. It consists of the review (in Polish) of performed research and of attached reprints from 16 original publications (in English) which A. Maj is the main or one of the main authors. All the studies were performed in collaboration with the groups from Milano and Copenhagen, using the HECTOR array equipment (described in chapter V). The Giant Dipole Resonance couples to the quadrupole degrees of freedom of the nucleus, and therefore constitutes a unique probe to test the shapes of atomic nuclei. In addition, the γ decay of the GDR from highly excited nuclei is a very fast process, it can compete with other modes of nuclear decay, and therefore can provide the information on the initial stages of excited nuclei. The presented investigations were concentrated on the following aspects: the shapes and thermal shape fluctuations, the origin of the behaviour of the GDR width, the properties of some exotic nuclei (Jacobi shapes, superdeformation, superheavy nuclei) and on ''entrance channel'' effects. The GDR γ decay was measured for nuclei with very different masses: from light nuclei with A≅45, through A≅110, 145,170,190, up to superheavy nuclei with A≅270. The shapes of hot nuclei are not fixed but fluctuate. The extent of these fluctuations and their influence on the measured quantities (GDR strength function, angular distribution and effective shape) is discussed in chapter VI.1. The observed width of the GDR is found to arise from the interplay of two effects: the thermal shape fluctuations, which are controlled by the nuclear temperature, and the deformation effects, controlled by the angular momentum. The ''collisional damping'' effect, which should influence the intrinsic GDR width, was found to be negligible (chapter VI.2). The GDR γ decay from hot superheavy nucleus 272 Hs

  15. Monopole transitions in hot nuclei

    International Nuclear Information System (INIS)

    Sujkowski, Z.

    1994-01-01

    Monopole transitions can be a signature of shape changing in a hot, pulsating nucleus (the low energy E0 mode) and/or a measure of the compressibility of finite nuclei (GMR, the breathing mode). Experimental information pertaining to GMR is reviewed. Recipes for deducing the incompressibility modules for infinite nuclear matter from data on GMR are discussed. Astrophysical implications are outlined. The first attempts at locating the GMR strength in moderately hot nuclei are described. Prospects for improving the experimental techniques to make an observation of this strength in selected nuclei unambiguous are discussed. (author). 46 refs, 8 figs

  16. Monopole transitions in hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Sujkowski, Z. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

    1994-12-31

    Monopole transitions can be a signature of shape changing in a hot, pulsating nucleus (the low energy E0 mode) and/or a measure of the compressibility of finite nuclei (GMR, the breathing mode). Experimental information pertaining to GMR is reviewed. Recipes for deducing the incompressibility modules for infinite nuclear matter from data on GMR are discussed. Astrophysical implications are outlined. The first attempts at locating the GMR strength in moderately hot nuclei are described. Prospects for improving the experimental techniques to make an observation of this strength in selected nuclei unambiguous are discussed. (author). 46 refs, 8 figs.

  17. High-Resolution Measurement of the {sup 4}He({gamma},n) Reaction in the Giant Resonance Region

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Bjoern

    2003-03-01

    A comprehensive near-threshold {sup 4}He(gamma,n) absolute cross section measurement has been performed at the high-resolution tagged-photon facility MAX-lab located in Lund, Sweden. The 20 < Eg < 45 MeV tagged photons (covering the Giant Dipole Resonance energy region) were directed towards a liquid {sup 4}He target, and knocked-out neutrons were detected in a pair of 60 cm x 60 cm vetoed NE213A liquid scintillator arrays. The intense and varying charge-neutral experimental backgrounds were carefully quantified and removed from the data using a precision fitting procedure. Eight average laboratory angles (30, 45, 60, 75, 90, 105, 120, and 135 deg) were investigated for eight photon energy bins (25, 27, 29, 31, 35, 36, 39, and 41 MeV), resulting in 64 differential cross sections. These angular distributions were integrated to produce total cross sections as a function of photon energy. The resulting cross sections peak at 1.9 mb at a photon energy of 27 MeV, and fall off to a near-constant value of 1.1 mb by 36 MeV. Further, they are in excellent agreement with those measured by Sims et al. using tagged photons in the Quasi-Deuteron energy region. Overall, the results favor modern theoretical models which are based upon a charge-symmetric nucleon-nucleon force, in marked contrast to the recommendations made by Calarco et al. in 1983 based on the sparse {sup 4}He(gamma,n) data available at the time.

  18. Search for magnetic monopoles with Frejus detector

    International Nuclear Information System (INIS)

    Benadjal, Y.

    1989-10-01

    Magnetic monopoles are predicted by every Grand Unification Theory. Their experimental search constitutes, together with proton decay, the only direct test of these theories. The Frejus experiment, using a large calorimetric detector, has looked for cosmic ray monopoles in the speed (v/c) range from 0.0001 to 0.1. No candidate was recorded. The flux limits obtained represent an original contribution at the low end of the speed range. After a first chapter covering various theoretical aspects of the monopole problem, we describe, in the following chapter, the main methods which can be applied to try to detect monopoles, and we review a certain number of experiments. The third chapter describes the Frejus magnetic monopole experiment. The detection method and the Geiger tube efficiency for slow monopoles are examined. Particular attention is given to the trigger system for slow monopoles. It was possible to add a specially designed electronic system to the detector making the monopole search possible. This system is described here. Four million events were recorded. The final chapter is devoted to their analysis. It includes, in particular, the description of the method which made it possible to reduce this mass of data to roughly 1000 events which were then scanned one by one in order to identify possible candidates. Our results in terms of flux limits are compared with those obtained by the better competing experiments [fr

  19. Monopole correlations in holographically flavored liquids

    NARCIS (Netherlands)

    Iqbal, N.

    2015-01-01

    Many-body systems with a conserved U(1) current in (2+1) dimensions may be probed by weakly gauging this current and studying correlation functions of magnetic monopole operators in the resulting dynamical gauge theory. We study such monopole correlations in holographic liquids with fundamental

  20. Search for Magnetic Monopoles with the NO$\

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zukai [Univ. of Virginia, Charlottesville, VA (United States)

    2015-09-01

    The magnetic monopole is a hypothetical particle, which is an important field configuration in many Grand Unified Theories, and whose mass may vary from 104 to 1018 GeV. The quantization of magnetic charge derived by Dirac in 1931 suggests the heavy ionization nature of magnetic monopoles. The NO$\

  1. Instantons, monopoles and chiral symmetry breaking

    International Nuclear Information System (INIS)

    Feurstein, M.; Markum, H.; Thurner, S.

    1996-01-01

    We analyze the interplay of topological objects in four dimensional QCD. The distributions of color magnetic monopoles obtained in the maximum abelian gauge are computed around instantons in both pure and full QCD. We find an enhanced probability of encountering monopoles inside the core of an instanton. We show this by means of local correlation functions of the topological variables. For specific gauge field configurations we visualize the situation graphically. Motivated by the fact that a fermion in the field of a static monopole has an energy zero mode we investigate how monopole loops and instantons are locally correlated with the chiral condensate. The observed correlations suggest that monopoles are involved in the mechanism of breaking of chiral symmetry. (orig.)

  2. Dynamics of a magnetic monopole in matter

    International Nuclear Information System (INIS)

    Fayolle, David

    1999-07-01

    We study the dynamics of a slow (v/c ∼ 10 -4 ) Dirac magnetic monopole in matter. First, we show at macroscopic scale that the force exerted on a monopole is F vector = g(H vector - v vector x D vector), as if the monopole was not allowed to cross neither microscopic current loops nor microscopic electric dipoles. We interpret this result in terms of adiabatic monopole-atom interactions. Secondly, we generalized the macroscopic Maxwell's equations in 'dual symmetric' matter which contains monopoles and dyons, from which we deduce several properties such as the velocity of light, the behaviour under C, P and T transformation, and we generalize the energy-momentum tensor. These equations also apply when nucleons or electrons possess an electric dipole moment and we propose two experimental methods for detecting this electric dipole moment via its macroscopic polarization effects. (author)

  3. Study of Gamow-Teller giant resonance in /sup 90/Nb by the /sup 90/Zr(/sup 3/He,t)/sup 90/Nb reaction at 90 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, M.; Fujita, Y.; Katayama, I.; Morinobu, S.; Yamazaki, T.; Itahashi, T.; Ikegami, H. [Osaka Univ., Suita (Japan). Research Center for Nuclear Physics; Hayakawa, S. I.; Ikegami, Hidetsugu; Muraoka, Mitsuo [eds.; Osaka Univ., Suita (Japan). Research Center for Nuclear Physics

    1980-01-01

    A Gamow-Teller giant resonance in /sup 90/Nb was excited by the /sup 90/Zr(/sup 3/He, t) reaction at 89.5 MeV. The strength of the resonance was localized in the energy region of Ex = 4.5 - 7.5 MeV. The transition was found to be dominated by the L = 2 transfer.

  4. Width and strength of the hot giant dipole resonance. The role of the life time of the compound nucleus and the transition from order to chaos

    International Nuclear Information System (INIS)

    Chomaz, P.

    1996-01-01

    A bump in the γ decay spectrum is observed at high energies which is due to the excitation of the Giant Dipole Resonance (GDR) in the compound nucleus. The fact is discussed that the total width of the γ-ray spectrum of the GDR transitions must contain twice the width of the compound nucleus levels. This implies that one must except a rapid increase of the width of the GDR. This increase contributes to the observed saturation of the photon multiplicity. A new suppression factor due to the lost of collectivity induced by the fast particle emission is proposed. (K.A.)

  5. Wavelet signatures of K-splitting of the Isoscalar Giant Quadrupole Resonance in deformed nuclei from high-resolution (p,p‧) scattering off 146, 148, 150Nd

    Science.gov (United States)

    Kureba, C. O.; Buthelezi, Z.; Carter, J.; Cooper, G. R. J.; Fearick, R. W.; Förtsch, S. V.; Jingo, M.; Kleinig, W.; Krugmann, A.; Krumbolz, A. M.; Kvasil, J.; Mabiala, J.; Mira, J. P.; Nesterenko, V. O.; von Neumann-Cosel, P.; Neveling, R.; Papka, P.; Reinhard, P.-G.; Richter, A.; Sideras-Haddad, E.; Smit, F. D.; Steyn, G. F.; Swartz, J. A.; Tamii, A.; Usman, I. T.

    2018-04-01

    The phenomenon of fine structure of the Isoscalar Giant Quadrupole Resonance (ISGQR) has been studied with high energy-resolution proton inelastic scattering at iThemba LABS in the chain of stable even-mass Nd isotopes covering the transition from spherical to deformed ground states. A wavelet analysis of the background-subtracted spectra in the deformed 146, 148, 150Nd isotopes reveals characteristic scales in correspondence with scales obtained from a Skyrme RPA calculation using the SVmas10 parameterization. A semblance analysis shows that these scales arise from the energy shift between the main fragments of the K = 0 , 1 and K = 2 components.

  6. Magnetic monopoles in a model of a composite photon

    International Nuclear Information System (INIS)

    Iwazaki, Aiichi.

    1984-10-01

    We show that there are monopole solutions in a composite model where the photon is regarded as a composite of elementary constituents. These monopoles have magnetic charges of the Dirac unit but are essencially different from 't Hooft-Polyakov monopoles since they are boundstates of the constituents. The stability of the monopoles is guaranteed by the conservation of the magnetic charges. (author)

  7. Monopole-antimonopole and vortex rings

    International Nuclear Information System (INIS)

    Teh, Rosy; Wong, Khai-Ming

    2005-01-01

    The SU(2) Yang-Mills-Higgs theory supports the existence of monopoles, antimonopoles, and vortex rings. In this paper, we would like to present new exact static antimonopole-monopole-antimonopole (A-M-A) configurations. The net magnetic charge of these configurations is always -1, while the net magnetic charge at the origin is always +1 for all positive integer values of the solution's parameter m. However, when m increases beyond 1, vortex rings appear coexisting with these AMA configurations. The number of vortex rings increases proportionally with the value of m. They are located in space where the Higgs field vanishes along rings. We also show that a single-point singularity in the Higgs field does not necessarily correspond to a structureless 1-monopole at the origin but to a zero-size monopole-antimonopole-monopole (MAM) structure when the solution's parameter m is odd. This monopole is the Wu-Yang-type monopole and it possesses the Dirac string potential in the Abelian gauge. These exact solutions are a different kind of Bogomol'nyi-Prasad-Sommerfield (BPS) solutions as they satisfy the first-order Bogomol'nyi equation but possess infinite energy due to a point singularity at the origin of the coordinate axes. They are all axially symmetrical about the z-axis

  8. Monopole gas in three dimensional SU(2) gluodynamics

    International Nuclear Information System (INIS)

    Chernodub, M.N.; Ishiguro, Katsuya; Suzuki, Tsuneo

    2004-01-01

    We study properties of the Abelian monopoles in the Maximal Abelian projection of the three dimensional pure SU(2) gauge model. We match the lattice monopole dynamics with the continuum Coulomb gas model using a method of blocking from continuum. We obtain the Debye screening length and the monopole density in continuum using numerical results for the density to the (squared) monopole charges and for the monopole action. The monopoles treated within our blocking method provide about 75% contribution to the non-Abelian Debye screening length. We also find that monopoles form a Coulomb plasma which is not dilute. (author)

  9. Decay of the isoscalar 1(h/2π)ω giant E3 resonance in 92Mo

    International Nuclear Information System (INIS)

    Klein, R.A.

    1984-01-01

    By means of the Heidelberg tandem-post accelerator combination the decay of the isoscalar 1 (h/2π)ω giant E3 resonance (LEOR) in 92 Mo was studied by (α, α', γ) coincidence measurements. At an incident energy of 50.4 MeV of the α particles the scattered helium nuclei were spectroscoped by eight semiconductor detectors in a maximum of the L=3 angular distribution. The γ quanta emitted coincidently by the excited target nuclei were detected in three high-resolution Ge diodes. Because of the good resolution both in the alpha and in the gamma branch for about 30 states in the excitation energy range of 1-7 MeV branching ratios for the gamma decay could be measured. For 16 of these levels lifetimes were determined by the Doppler-shift attenuation method. Starting from the determined branching ratios and typical lifetimes (40-90 fs) for 3 - states in the excitation-energy range of the LEOR (5-10 MeV) an earlier reported strong ground-state decay (8%) of the LEOR can be excluded. Rather the LEOR decays so as it is expected by the model of the statistical decay namely dominantly to low-lying 3 - , 4 - , and above all 5 - levels. A likewise reported strong E1-decay of the LEOR to the 2 + 1 state in 90 Zr which is implicated in the framework of a collective model in connection with the E3 ground-state transitions can in 92 Mo also not be confirmed. In spite of the strongly collective nature of the first 2 + state in 92 Mo an increased LEOR decay to this level was not observed. Against that in the LEOR region ground-state transitions of 1 - states with isoscalar nature were spectroscoped. The observation of these levels is also reproduced by performed RPA calculations. A parallel measurement on 90 Zr confirms the results of this thesis. (orig./HSI) [de

  10. Magnetic monopoles and dipoles in quantum mechanics

    International Nuclear Information System (INIS)

    Lipkin, H.J.; Peshkin, M.

    1986-01-01

    The force on and the energy of a ''di-monopole'', which is the limiting case of a dipole made from two monopoles at zero separation and finite magnetic moment, interacting with an externally fixed magnetic field resulting from an electric current, is considered. A model involving only a monopole is used to illustrate the physical principles involved when magnetic sources move in a solenoidal field whose source is an electric current. The problems encountered in Hamiltonian theory are discussed. 5 refs., 3 figs

  11. Monopole charges in unified gauge theories

    CERN Document Server

    Chan Hong Mo

    1981-01-01

    Monopole charges, being global quantities, depend on the gauge group of a theory, which in turn is determined by the representations of all its fields. For example, chromodynamics in its present form when combined with electrodynamics has as its gauge group not SU(3)*U(1) but a 'smaller' group U(3). The specification of monopole charges for a theory can thus be quite intricate. The authors report the result of an investigation in several current gauge theories. Of particular interest is the possible existence in some theories of monopoles carrying multiplicative charges. As a by-product, some earlier assertions seem to be incorrect, are clarified. (16 refs).

  12. Magnetic Monopole Search at the SPS

    CERN Multimedia

    2002-01-01

    A target made of fine grains of tungsten-iron powder will be exposed to the 400 GeV proton beam in front of the narrow-band neutrino beam dump. Magnetic monopoles if produced by the proton interactions will be trapped in the target. After exposure, the target will be placed in the centre of a pulse magnetic coil with nuclear emulsions acting as monopole detectors. .sp \\\\ \\\\ A monopole mass sensitivity up to 18 GeV is expected in this experiment.

  13. Description of giant resonances

    International Nuclear Information System (INIS)

    Lane, A.M.

    1975-01-01

    The history of collective theories in nuclear physics is briefly reviewed. It is emphasised that some theories (like RPA) allow collectivity to emerge from calculations, while others (like GCM) essentially impose a collective framework from teh start. The former class has the incidental merit that it treats spreading of collective states arising from interaction with (discrete and continuum) particle excitations. A problem with the RPA calculations is that they are almost too detailed if one's interest is in exposing systematic qualitative features. The speaker (along with co-authors) has developed a sum-rule method for exposing such trends. It is based on the fact that one can readily evaluate three sum-rules; in addition to the familiar one with plus-one power of energy-weighting, those with minus-one and plus-three powers can be evaluated for RPA states in closed form. From the three moments, the energy and spread of the collective state can be obtained. Amongst other things, the approach gives a very simple derivation of the Suzuki-Mottelson result that collective energy equals √2 times the oscillator quantum. (orig.) [de

  14. USING SCHUMANN RESONANCE MEASUREMENTS FOR CONSTRAINING THE WATER ABUNDANCE ON THE GIANT PLANETS-IMPLICATIONS FOR THE SOLAR SYSTEM'S FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Simoes, Fernando; Pfaff, Robert; Klenzing, Jeffrey; Freudenreich, Henry; Bromund, Kenneth; Martin, Steven; Rowland, Douglas [NASA/GSFC, Heliophysics Science Division, Space Weather Laboratory (Code 674), Greenbelt, MD (United States); Hamelin, Michel; Berthelier, Jean-Jacques [LATMOS/IPSL, UPMC, Paris (France); Beghin, Christian; Lebreton, Jean-Pierre [LPC2E, CNRS/Universite d' Orleans (France); Grard, Rejean [ESA/ESTEC, Research Scientific Support Department, Noordwijk (Netherlands); Sentman, Davis [Institute of Geophysics, University of Alaska Fairbanks, Fairbanks, AK (United States); Takahashi, Yukihiro [Department of Geophysics, Tohoku University, Sendai (Japan); Yair, Yoav [Department Life Natural Sciences, Open University of Israel, Raanana (Israel)

    2012-05-01

    The formation and evolution of the solar system is closely related to the abundance of volatiles, namely water, ammonia, and methane in the protoplanetary disk. Accurate measurement of volatiles in the solar system is therefore important for understanding not only the nebular hypothesis and origin of life but also planetary cosmogony as a whole. In this work, we propose a new remote sensing technique to infer the outer planets' water content by measuring Tremendously and Extremely Low Frequency (TLF-ELF) electromagnetic wave characteristics (Schumann resonances) excited by lightning in their gaseous envelopes. Schumann resonance detection can be potentially used for constraining the uncertainty of volatiles of the giant planets, mainly Uranus and Neptune, because such TLF-ELF wave signatures are closely related to the electric conductivity profile and water content.

  15. Destruction of /sup 18/O in red giants. A search for a sub-threshold resonance in the /sup 18/O+p system

    Energy Technology Data Exchange (ETDEWEB)

    Champagne, A E; Pitt, M L

    1986-09-08

    The /sup 18/O(/sup 3/He,d)/sup 19/F reaction has been used to determine if a presumed sub-threshold resonance at Esub(c.m.)=-94 KeV in the /sup 18/O(p,..cap alpha..)/sup 15/N reaction exists at an astrophysically significant level. No evidence for this state was observed which implies a dimensionless reduced width thetasub(p)/sup 2/<5 . 10/sup -5/. In addition, a proton width GAMMAsub(p)=2 x 10/sup -19/ eV has been determined for a d-wave resonance located at Esub(c.m.)=20 keV. The resulting thermonuclear reaction rate is slow enough to ensure that /sup 18/O is not destroyed at red-giant temperatures.

  16. Evaluation of dynamic response for monopole and hybrid wind mill tower

    Science.gov (United States)

    Shah, Hemal J.; Desai, Atul K.

    2017-07-01

    The wind mill towers are constructed using monopoles or lattice type tower. As the height of tower increases it gives more power but it becomes uneconomical, so in the present research work innovative wind mill tower such as combination of monopole and lattice tower is analyzed using FEM software. When the tall structures are constructed on soft soil it becomes dynamically sensitive so 3 types of soil such as hard, medium and soft soil is also modeled and the innovative tower is studied for different operating frequencies of wind turbine. From study it is concluded that the innovative tower will reduce resonance condition considering soil structure interaction.

  17. Superheavy magnetic monopoles and the standard cosmology

    International Nuclear Information System (INIS)

    Turner, M.S.

    1984-10-01

    The superheavy magnetic monopoles predicted to exist in grand unified theories (GUTs) are very interesting obsects, both from the point of view of particle physics, as well as from astrophysics and cosmology. Astrophysical and cosmological considerations have proved to be invaluable in studying the properties of GUT monopoles. Because of the glut of monopoles predicted in the standard cosmology for the simplest GUTs (so many that the Universe should have reached a temperature of 3 0 K at the tender age of approx. = 10,000 yrs), the simplest GUTs and the standard cosmology are not compatible. This is a very important piece of information about physics at unification energies (E greater than or equal to 10 14 GeV) and about the earliest moments (t less than or equal to 10 -34 s) of the Universe. In this talk the author reviews the cosmological consequences of GUT monopoles within the context of the standard hot big bang model. 46 references

  18. Multi-monopoles and magnetic bags

    International Nuclear Information System (INIS)

    Bolognesi, Stefano

    2006-01-01

    By analogy with the multi-vortices, we show that also multi-monopoles become magnetic bags in the large n limit. This simplification allows us to compute the spectrum and the profile functions by requiring the minimization of the energy of the bag. We consider in detail the case of the magnetic bag in the limit of vanishing potential and we find that it saturates the Bogomol'nyi bound and there is an infinite set of different shapes of allowed bags. This is consistent with the existence of a moduli space of solutions for the BPS multi-monopoles. We discuss the string theory interpretation of our result and also the relation between the 't Hooft large n limit of certain supersymmetric gauge theories and the large n limit of multi-monopoles. We then consider multi-monopoles in the cosmological context and provide a mechanism that could lead to their production

  19. SU(5) monopoles, magnetic symmetry and confinement

    International Nuclear Information System (INIS)

    Daniel, M.; Lazarides, G.; Shafi, Q.

    1980-01-01

    The monopoles of the unified SU(5) gauge theory broken down to Hsub(E) = SU(3)sub(c) x U(1)sub(EM) [or to Ksub(E) = SU(3)sub(c) x SU(2) x U(1)sub(γ)], are classified. They belong to representations of a magnetic group Hsub(M)(Ksub(M)), which is found to be isomorphic to Hsub(E)(Ksub(E)). For SU(5) broken down to Hsub(E), there exists a regular and stable monopole which is a colour magnetic triplet, and carries a non-zero abelian magnetic charge. It is suggested that composite operators made out of this monopole and its antiparticle fields develop a non-zero vacuum expectation value, and so lead to a squeezing of the colour electric flux. Finally, we comment on the cosmological production of SU(5) monopoles. (orig.)

  20. Type A Jacobi Elliptic One-Monopole

    International Nuclear Information System (INIS)

    Teh, Rosy; Wong, Khai-Ming

    2010-01-01

    We present new classical generalized one-monopole solution of the SU(2) Yang-Mills-Higgs theory with the Higgs field in the adjoint representation. We show that this generalized solution with Θ-winding number m = 1 and φ-winding number n = 1 is an axially symmetric Jacobi elliptic generalization of the 't Hooft-Polyakov one-monopole. We construct this axially symmetric one-monopole solution by generalizing the large distance asymptotic solution of the 't Hooft-Polyakov one-monopole to the Jacobi elliptic functions and solving the second order equations of motion numerically when the Higgs potential is vanishing. This solution is a regular non-BPS finite energy solution.

  1. Contribution of giant resonances in elastic and inelastic scattering of polarized protons on 12C between 19 and 23MeV

    International Nuclear Information System (INIS)

    Gaillard, Y.R.

    1975-01-01

    Angular distributions of analyzing power and differential cross section have been measured for the elastic and inelastic scattering of polarized protons on 12 C, up to 12.7MeV excitation energy. Incident energy varied from 19 to 23MeV by steps of about 200keV, the cyclotron beam energy, varying by steps of about 1MeV, was measured using crossover techniques. Fine steps of energy were obtained by use of carbon absorbers. Elastic scattering data were analyzed using a linear energy-dependent optical model. Data for the level at 4.4MeV excitation energy were analyzed using coupled channel calculations. Preliminary results for the level (1 - , Esub(x)=12.7MeV) were analyzed including giant resonances as doorways states in inelastic scattering, according to Geramb-Amos formalism. This analysis shows that it should be possible to study high-lying giant resonances through their contribution to low-lying state excitation [fr

  2. Magnetic monopole catalysis of proton decay

    International Nuclear Information System (INIS)

    Marciano, W.J.; Salvino, D.

    1986-09-01

    Catalysis of proton decay by GUT magnetic monopoles (the Rubakov-Callan effect) is discussed. Combining a short-distance cross section calculation by Bernreuther and Craigie with the long-distance velocity dependent distortion factors of Arafune and Fukugita, catalysis rate predictions which can be compared with experiment are obtained. At present, hydrogen rich detectors such as water (H 2 O) and methane (CH 4 ) appear to be particularly well suited for observing catalysis by very slow monopoles. 17 refs., 1 fig

  3. Annihilation and gravitational clumping of monopoles in the early universe

    International Nuclear Information System (INIS)

    Izawa, Mizuo; Sato, Katsuhiko.

    1983-01-01

    In order to avoid the overproduction of magnetic monopoles in the early Universe, we investigate how monopoles evolve in the Big Bang Universe for arbitrary mass of monopoles and the arbitrary initial abundance. First, we calculate pair annihilation of monopoles by taking into account the entropy production due to the annihilations. Second, we investigate the formation of monopole stars and black holes due to gravitational clumping of monopoles. In particular, we take into account the entropy and baryon number generation by black hole evaporation. It is shown, however, that the burning of monopole stars or the evaporation of black holes cannot dilute the monopole abundance sufficiently without conflicts with present baryon/entropy ratio and primordial nucleosynthesis regardless of monopole mass. (author)

  4. Extended Monopole antenna Array with individual Shield (EMAS) coil: An improved monopole antenna design for brain imaging at 7 tesla MRI.

    Science.gov (United States)

    Woo, Myung-Kyun; Hong, Suk-Min; Lee, Jongho; Kang, Chang-Ki; Park, Sung-Yeon; Son, Young-Don; Kim, Young-Bo; Cho, Zang-Hee

    2016-06-01

    To propose a new Extended Monopole antenna Array with individual Shields (EMAS) coil that improves the B1 field coverage and uniformity along the z-direction. To increase the spatial coverage of Monopole antenna Array (MA) coil, each monopole antenna was shielded and extended in length. Performance of this new coil, which is referred to as EMAS coil, was compared with the original MA coil and an Extended Monopole antenna Array coil with no shield (EMA). For comparison, flip angle, signal-to-noise ratio (SNR), and receive sensitivity maps were measured at multiple regions of interest (ROIs) in the brain. The EMAS coil demonstrated substantially larger flip angle and receive sensitivity than the MA and EMA coils in the inferior aspect of the brain. In the brainstem ROI, for example, the flip angle in the EMAS coil was increased by 45.5% (or 60.0%) and the receive sensitivity was increased by 26.9% (or 14.9%), resulting in an SNR gain of 84.8% (or 76.3%) when compared with the MA coil (or EMA). The EMAS coil provided 25.7% (or 24.4%) more uniform B1+ field distribution compared with the MA (or EMA) coil in sagittal. The EMAS coil successfully extended the imaging volume in lower part of the brain. Magn Reson Med 75:2566-2572, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  5. Econometric Methodology of Monopolization Process Evaluation

    Directory of Open Access Journals (Sweden)

    Dmitrijs Skoruks

    2014-06-01

    Full Text Available The research “Econometric Methodology of Monopolization Process Evaluation” gives a perspective description of monopolization process’ nature, occurrence source, development procedure and internal conjuncture specifics, as well as providing an example of modern econometrical method application within a unified framework of market competition analysis for the purpose of conducting a quantitative competition evaluation on an industry level for practical use in both private and public sectors. The main question of the aforementioned research is the definition and quantitative analysis of monopolization effects in modern day globalized markets, while con- structing an empirical model of the econometric analysis, based on the use of in- ternational historical experience of monopoly formations standings, with the goal of introducing a further development scheme for the use of both econometrical and statistical instruments in line with the forecasting and business research need of enterprises and regulatory functions of the public sector. The current research uses a vast variety of monopolization evaluation ratios and their econometrical updates on companies that are involved in the study procedure in order to detect and scallar measure their market monopolizing potential, based on the implemented acquired market positions, turnover shares and competition policies.

  6. The isomeric ratios in photonuclear reactions of natural barium induced by bremsstrahlungs with endpoint energies in the giant dipole resonance region

    International Nuclear Information System (INIS)

    Tran Duc Thiep; Truong Thi An; Phan Viet Cuong; Nguyen The Vinh

    2012-01-01

    We have determined the isomeric ratios in 130 Ba(γ, n) 129m,g Ba, 132 Ba(γ, n) 131m,g Ba and 134 Ba(γ, n) 133m,g Ba photonuclear reactions of natural barium induced by bremsstrahlungs with end-point energies in the giant dipole resonance region. The investigated samples were irradiated at electron accelerator Microtron MT-25 of the Flerov Laboratory of Nuclear Reaction, Joint Institute for Nuclear Research, Dubna, Russia. The gamma spectra of the samples irradiated were measured with spectroscopic system consisting of 8192 channel analyzer and high-energy resolution (180 keV at gamma ray 1332 keV of 60 Co) HP(Ge) semiconductor detector Canberra. The GENIE2000 (Canberra) computer program was used for data processing. The results were discussed and compared with those of other authors. (author)

  7. The Price of an Electroweak Monopole

    CERN Document Server

    Ellis, John; You, Tevong

    2016-01-01

    In a recent paper, Cho, Kim and Yoon (CKY) have proposed a version of the SU(2) $\\times$ U(1) Standard Model with finite-energy monopole and dyon solutions. The CKY model postulates that the effective U(1) gauge coupling $\\to \\infty$ very rapidly as the Englert-Brout-Higgs vacuum expectation value $\\to 0$, but in a way that is incompatible with LHC measurements of the Higgs boson $H \\to \\gamma \\gamma$ decay rate. We construct generalizations of the CKY model that are compatible with the $H \\to \\gamma \\gamma$ constraint, and calculate the corresponding values of the monopole and dyon masses. We find that the monopole mass could be $< 5.5$ TeV, so that it could be pair-produced at the LHC and accessible to the MoEDAL experiment.

  8. Some remarkable spin physics with monopoles and fermions

    International Nuclear Information System (INIS)

    Craigie, N.S.

    1984-01-01

    This review will cover the following topics, which follow the historical evolution of the subject: the Dirac monopole; the Kazama-Yang Goldhaber problem in electron-monopole scattering; the 't Hooft-Polyakov monopole and spin from isospin; the Rubakov analysis; monopole catalysis of proton decay the Rubakov-Callan effect; the role of exactly solvable 2-dimensional QFT's and finally observable consequences. 15 references

  9. Some remarkable spin physics with monopoles and fermions

    International Nuclear Information System (INIS)

    Craigie, N.S.

    1984-09-01

    This review will cover the following topics, which follow the historical evolution of the subject: the Dirac monopole, the Kazama-Yang Goldhaber problem in electron-monopole scattering; the 't Hooft-Polyakov monopole and spin from isospin; the Rubakov analysis; monopole catalysis of proton decay- ''the Rubakov-Callan effect''; the role of exactly solvable 2-dimensional QFT's and finally observable consequences. (author)

  10. Stable SU(5) monopoles with higher magnetic charge

    International Nuclear Information System (INIS)

    Miyamoto, S.; Sato, H.; Tomohiro, S.

    1985-01-01

    Taking into account the electroweak breaking effects, some multiply charged monopoles were shown to be stable by Gardner and Harvey. We give the explicit Ansa$uml: tze for finite-energy, nonsingular solutions of these stable higher-strength monopoles with eg = 1,(3/2),3. We also give the general stability conditions and the detailed behavior of the interaction potentials between two monopoles which produce the stable higher-strength monopoles

  11. Vacuum anti-shielding of monopoles

    International Nuclear Information System (INIS)

    Goebel, D.J.

    1984-01-01

    This chapter examines the difficulties in calculating the vacuum polarization, or magnetization, induced in the vacuum by a monopole. The usual Lagrangian formalism and consequent Feynman rules do not apply. Another problem is that the interaction strength between the monopole and a charge is not small (unless it vanishes exactly) because it is quantized to half integer values. Perturbation theory is therefore not applicable. The discussed problems are solved by using the old fashioned method of calculating a vacuum expectation value as a sum over single particle modes

  12. Monopole Solutions in Topologically Massive Gauge Theory

    International Nuclear Information System (INIS)

    Teh, Rosy; Wong, Khai-Ming; Koh, Pin-Wai

    2010-01-01

    Monopoles in topologically massive SU(2) Yang-Mils-Higgs gauge theory in 2+1 dimensions with a Chern-Simon mass term have been studied by Pisarski some years ago. He argued that there is a monopole solution that is regular everywhere, but found that it does not possess finite action. There were no exact or numerical solutions being presented by him. Hence it is our purpose to further investigate this solution in more detail. We obtained numerical regular solutions that smoothly interpolates between the behavior at small and large distances for different values of Chern-Simon term strength and for several fixed values of Higgs field strength.

  13. Analysis of a reported magnetic monopole

    International Nuclear Information System (INIS)

    Alvarez, L.W.

    1975-01-01

    It is shown that there are several substantive errors in a previous work on a cosmic ray event which is consistent with the hypothesis that it was caused by a magnetic monopole. It is shown that the data points fit to the hypothesis that the responsible particle is a platinum nucleus fragmenting to osmium and then to tantalum

  14. Magnetic monopoles, Galilean invariance, and Maxwell's equations

    International Nuclear Information System (INIS)

    Crawford, F.S.

    1992-01-01

    Maxwell's equations have space reserved for magnetic monopoles. Whether or not they exist in our part of the universe, monopoles provide a useful didactic tool to help us recognize relations among Maxwell's equations less easily apparent in the approach followed by many introductory textbooks, wherein Coulomb's law, Biot and Savart's law, Ampere's law, Faraday's law, Maxwell's displacement current, etc., are introduced independently, ''as demanded by experiment.'' Instead a conceptual path that deduces all of Maxwell's equations from the near-minimal set of assumptions: (a) Inertial frames exist, in which Newton's laws hold, to a first approximation; (b) the laws of electrodynamics are Galilean invariant---i.e., they have the same form in every inertial frame, to a first approximation; (c) magnetic poles (as well as the usual electric charges) exist; (d) the complete Lorentz force on an electric charge is known; (e) the force on a monopole at rest is known; (f) the Coulomb-like field produced by a resting electric charge and by a resting monopole are known. Everything else is deduced. History is followed in the assumption that Newtonian mechanics have been discovered, but not special relativity. (Only particle velocities v much-lt c are considered.) This ends up with Maxwell's equations (Maxwell did not need special relativity, so why should we,) but facing Einstein's paradox, the solution of which is encapsulated in the Einstein velocity-addition formula

  15. Conservation of basic monopoles in decay processes

    International Nuclear Information System (INIS)

    Barricelli, N.A.

    1983-01-01

    The conversation law of basic monpoles and other rules followed by these monopoles in the formation and decay processes of elementary particles are presented and discussed. A new interpretation of the distinction between rapid decay process (commonly ascribed to weak interactions) is proposed. (Auth.)

  16. Charged particles as Kaluza-Klein monopoles

    International Nuclear Information System (INIS)

    Chan, H.-M.; Tsou, S.T.

    1984-05-01

    The authors describe some explorations into the possibility of treating charged particles as monopoles in a Kaluza-Klein world. Such considerations may be useful in the future for constructing model theories in which both matter and gauge structure emerge as consequences of space-time geometry. (author)

  17. Monopole star products are non-alternative

    Energy Technology Data Exchange (ETDEWEB)

    Bojowald, Martin [Institute for Gravitation and the Cosmos, The Pennsylvania State University,104 Davey Lab, University Park, PA 16802 (United States); Brahma, Suddhasattwa [Institute for Gravitation and the Cosmos, The Pennsylvania State University,104 Davey Lab, University Park, PA 16802 (United States); Center for Field Theory and Particle Physics, Fudan University,200433 Shanghai (China); Büyükçam, Umut [Institute for Gravitation and the Cosmos, The Pennsylvania State University,104 Davey Lab, University Park, PA 16802 (United States); Strobl, Thomas [Institut Camille Jordan, Université Claude Bernard Lyon 1,43 boulevard du 11 novembre 1918, 69622 Villeurbanne cedex (France)

    2017-04-05

    Non-associative algebras appear in some quantum-mechanical systems, for instance if a charged particle in a distribution of magnetic monopoles is considered. Using methods of deformation quantization it is shown here, that algebras for such systems cannot be alternative, i.e. their associator cannot be completely anti-symmetric.

  18. On the supersymmetric solitons and monopoles

    International Nuclear Information System (INIS)

    Hruby, J.

    1978-01-01

    The basic results in a new trend in supersymmetry and soliton theory are presented. It is shown that the soliton expectation value of the energy operator is mass of the soliton without the quantum corrections. A new supersymmetric monopole model in three dimensions is constructed by generalization of the supersymmetric sine-Gordon model in one space dimension

  19. f(R) global monopole revisited

    Energy Technology Data Exchange (ETDEWEB)

    Carames, Thiago R.P.; Fabris, Julio C.; Belich, H. [Universidade Federal do Espirito Santo (UFES), Vitoria, ES (Brazil); Bezerra de Mello, E.R. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil)

    2017-07-15

    In this paper the f(R) global monopole is reexamined. We provide an exact solution for the modified field equations in the presence of a global monopole for regions outside its core, generalizing previous results. Additionally, we discuss some particular cases obtained from this solution. We consider a setup consisting of a possible Schwarzschild black hole that absorbs the topological defect, giving rise to a static black hole endowed with a monopole's charge. Besides, we demonstrate how the asymptotic behavior of the Higgs field far from the monopole's core is shaped by a class of spacetime metrics which includes the ones analyzed here. In order to assess the gravitational properties of this system, we analyze the geodesic motion of both massive and massless test particles moving in the vicinity of such configuration. For the material particles we set the requirements they have to obey in order to experience stable orbits. On the other hand, for the photons we investigate how their trajectories are affected by the gravitational field of this black hole. (orig.)

  20. Predation, Exclusion, and Complement Market Monopolization

    OpenAIRE

    Timothy Brennan

    2009-01-01

    The handling of cases under the rubrics “monopolization,†“single-firm conduct,†or “abuse of dominance†continues to be debated by the competition policy community.

  1. Magnetic monopoles, duality and cosmological phase transitions

    International Nuclear Information System (INIS)

    Escobar, C.O.; Natale, A.A.; Marques, G.C.

    1981-06-01

    Is is shown that duality for magnetic monopoles, as proposed by Montonen and Olive, does not hold in quatum field theory at finite temperatures. Furthermore, the evolution picture of the Universe looks different when analyzed in the original 'electric' theory or in its dual 'magnetic' counterpart. (Author) [pt

  2. Cosmological grand unification monopoles: astrophysical constraints

    International Nuclear Information System (INIS)

    Fry, J.N.

    1982-01-01

    I review the general arguments which suggest that relic GU magnetic monopoles should emerge from the early universe, and I discuss several astrophysical settings in which their effects could be, but are not, observed. This places limits on their possible flux, and their abundance bound to more ordinary material

  3. Multi-band Monopole Antennas Loaded with Metamaterial TL

    Science.gov (United States)

    Song, Zhi-jie; Liang, Jian-gang

    2015-05-01

    A novel metamaterial transmission line (TL) by loading complementary single Archimedean spiral resonator pair (CSASRP) is investigated and used to design a set of multi-frequency monopole antennas. The particularity is that the CSASRP which features dual-shunt branches in the equivalent circuit model is directly etched in the signal strip. By smartly controlling the element parameters, three antennas are designed and one of them covering UMTS and Bluetooth bands is fabricated and measured. The antenna exhibits impedance matching better than -10 dB and normal monopolar radiation patterns at working bands of 1.9-2.22 and 2.38-2.5 GHz. Moreover, the loaded element also contributes to the radiation, which is the major advantage of this prescription over previous lumped-element loadings. The proposed antenna is also more compact over previous designs.

  4. Algebraic properties of the monopole formula

    Energy Technology Data Exchange (ETDEWEB)

    Hanany, Amihay [Theoretical Physics Group, Imperial College London,Prince Consort Road, London, SW7 2AZ (United Kingdom); Sperling, Marcus [Fakultät für Physik, Universität Wien,Boltzmanngasse 5, 1200 Wien (Austria)

    2017-02-06

    The monopole formula provides the Hilbert series of the Coulomb branch for a 3-dimensional N=4 gauge theory. Employing the concept of a fan defined by the matter content, and summing over the corresponding collection of monoids, allows the following: firstly, we provide explicit expressions for the Hilbert series for any gauge group. Secondly, we prove that the order of the pole at t=1 and t→∞ equals the complex or quaternionic dimension of the moduli space, respectively. Thirdly, we determine all bare and dressed BPS monopole operators that are sufficient to generate the entire chiral ring. As an application, we demonstrate the implementation of our approach to computer algebra programs and the applicability to higher rank gauge theories.

  5. One Monopole-Antimonopole Pair Solutions

    International Nuclear Information System (INIS)

    Teh, Rosy; Wong, K.-M.

    2009-01-01

    We present new classical generalized one monopole-antimonopole pair solutions of the SU(2) Yang-Mills-Higgs theory with the Higgs field in the adjoint representation. We show that in general the one monopole-antimonopole solution need not be solved by imposing mθ-winding number to be integer greater than one. We also show that this solution can be solved when m = 1 by transforming the large distance asymptotic solutions to general solutions that depend on a parameter p. Secondly we show that these large distance asymptotic solutions can be further generalized to the Jacobi elliptic functions. We focus our numerical calculation on the Jacobi elliptic functions solution when the nφ-winding number is one and show that this generalized Jacobi elliptic 1-MAP solution possesses lower energy. All these solutions are numerical finite energy non-BPS solutions of the Yang-Mills-Higgs field theory.

  6. X-ray excited photoluminescence near the giant resonance in solid-solution Gd(1-x)Tb(x)OCl nanocrystals and their retention upon solvothermal topotactic transformation to Gd(1-x)Tb(x)F3.

    Science.gov (United States)

    Waetzig, Gregory R; Horrocks, Gregory A; Jude, Joshua W; Zuin, Lucia; Banerjee, Sarbajit

    2016-01-14

    Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb(3+) centers upon excitation in proximity to the giant resonance of the host Gd(3+) ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism from multiple exciton generation to single thermal exciton formation and Auger decay processes. The solid-solution Gd1-xTbxOCl nanocrystals are further topotactically transformed with retention of a nine-coordinated cation environment to solid-solution Gd1-xTbxF3 nanocrystals upon solvothermal treatment with XeF2. The metastable hexagonal phase of GdF3 can be stabilized at room temperature through this topotactic approach and is transformed subsequently to the orthorhombic phase. The fluoride nanocrystals indicate an analogous but blue-shifted modulation of the X-ray excited optical luminescence of the Tb(3+) centers upon X-ray excitation near the giant resonance of the host Gd(3+) ions.

  7. Detector for magnetic monopoles at OPAL

    International Nuclear Information System (INIS)

    Pinfold, J.L.; Kinoshita, K.; Lorazo, B.; Regimbald, M.

    1991-01-01

    We describe two indepent methods, employed in the OPAL experiment at LEP, for detection of magnetic monopoles and other highly ionizing particles. The first employs passive track-recording plastic detectors incorporated into the apparatus. The second utilizes thed dE/dX measurement capability of the OPAL JET chamber in association with a dedicated trigger. In addition, energetic particles carrying magnetic charge can be identified by the trajectory in the OPAL magnetic field. (orig.)

  8. Magnetic monopole dynamics in spin ice.

    Science.gov (United States)

    Jaubert, L D C; Holdsworth, P C W

    2011-04-27

    One of the most remarkable examples of emergent quasi-particles is that of the 'fractionalization' of magnetic dipoles in the low energy configurations of materials known as 'spin ice' into free and unconfined magnetic monopoles interacting via Coulomb's 1/r law (Castelnovo et al 2008 Nature 451 42-5). Recent experiments have shown that a Coulomb gas of magnetic charges really does exist at low temperature in these materials and this discovery provides a new perspective on otherwise largely inaccessible phenomenology. In this paper, after a review of the different spin ice models, we present detailed results describing the diffusive dynamics of monopole particles starting both from the dipolar spin ice model and directly from a Coulomb gas within the grand canonical ensemble. The diffusive quasi-particle dynamics of real spin ice materials within the 'quantum tunnelling' regime is modelled with Metropolis dynamics, with the particles constrained to move along an underlying network of oriented paths, which are classical analogues of the Dirac strings connecting pairs of Dirac monopoles.

  9. Compactness and gluing theory for monopoles

    CERN Document Server

    Frøyshov, Kim A

    2008-01-01

    This book is devoted to the study of moduli spaces of Seiberg-Witten monopoles over spinc Riemannian 4–manifolds with long necks and/or tubular ends. The original purpose of this work was to provide analytical foundations for a certain construction of Floer homology of rational homology 3–spheres; this is carried out in [Monopole Floer homology for rational homology 3–spheres arXiv:08094842]. However, along the way the project grew, and, except for some of the transversality results, most of the theory is developed more generally than is needed for that construction. Floer homology itself is hardly touched upon in this book, and, to compensate for that, I have included another application of the analytical machinery, namely a proof of a "generalized blow-up formula" which is an important tool for computing Seiberg–Witten invariants. The book is divided into three parts. Part 1 is almost identical to my paper [Monopoles over 4–manifolds containing long necks I, Geom. Topol. 9 (2005) 1–93]. The oth...

  10. Giant grains

    International Nuclear Information System (INIS)

    Leitch-Devlin, M.A.; Millar, T.J.; Williams, D.A.

    1976-01-01

    Infrared observations of the Orion nebula have been interpreted by Rowan-Robinson (1975) to imply the existence of 'giant' grains, radius approximately 10 -2 cm, throughout a volume about a parsec in diameter. Although Rowan-Robinson's model of the nebula has been criticized and the presence of such grains in Orion is disputed, the proposition is accepted, that they exist, and in this paper situations in which giant grains could arise are examined. It is found that, while a giant-grain component to the interstellar grain density may exist, it is difficult to understand how giant grains arise to the extent apparently required by the Orion nebula model. (Auth.)

  11. Excitation of simple atoms by slow magnetic monopoles

    International Nuclear Information System (INIS)

    Kroll, N.M.; Parke, S.J.; Ganapathi, V.; Drell, S.D.

    1984-01-01

    We present a theory of excitation of simple atoms by slow moving massive monopoles. Previously presented results for a monopole of Dirac strength on hydrogen and helium are reviewed. The hydrogen theory is extended to include arbitrary integral multiples of the Dirac pole strength. The excitation of helium by double strength poles and by dyons is also discussed. It is concluded that a helium proportional counter is a reliable and effective detector for monopoles of arbitrary strength, and for negatively charged dyons

  12. Monopole excitations of the 12C nucleus in the cluster model

    International Nuclear Information System (INIS)

    Mikhelashvili, T.Ya.; Shirokov, A.M.; Smirnov, Yu.F.

    1990-01-01

    The monopole excitations of the 12 C nucleus are studied in the 3α-cluster model. The 3α-continuum is taken into account by means of scattering theory in the harmonic oscillator representation. Only the 'true' three-body scattering is considered. The role of the continuum is essential. Particularly, at excitation energies between 12-25 MeV, instead of a number of sharp resonances, a single smooth resonance on a broad pedestal arises. The pedestal may be easily misinterpreted as a 'background' in experimental studies. (author)

  13. Searching for magnetic monopoles using large area ionization detectors

    International Nuclear Information System (INIS)

    Shepko, M.J.; Webb, R.C.

    1984-01-01

    Predictions of current Grand Unified Theories (GUT's) require the existence of massive (10 16 GeV/c 2 ) magnetic monopoles at some level. Stringent limits on the flux of these particles may be obtained from various cosmological and astrophysical arguments. Theoretical predictions limiting monopole abundance based on survival of the galactic magnetic field place an upper bound of xi approx. = 10 -15 cm -2 sr -1 s -1 on the allowed monopole flux. Similarly, magnetic monopoles are expected to be accelerated along galactic field lines to velocities on the order of β approx. = 10 -4

  14. Status of the Texas A and M GUT monopole search

    International Nuclear Information System (INIS)

    Webb, R.C.

    1984-01-01

    This chapter describes the use of a large area (approx. 53 m 2 ) scintillation counter telescope to detect the passage of a slow moving, superheavy, magnetic monopole. The detector is described and the expected signature for a passing magnetic monopole is presented. The detector utilizes acrylic based scintillation material as the detector medium. The electronics for the monopole search were selected and designed to be sensitive to the properties of the Grand Unified Theory (GUT) monopoles. The described experiment is located underground at a depth of 1500' in a nearby salt mine

  15. Searches for magnetic monopoles with IceCube

    Directory of Open Access Journals (Sweden)

    Pollmann Anna

    2018-01-01

    IceCube is a high energy neutrino detector using the clear ice at the South Pole as a detection medium. As monopoles pass through this ice they produce optical light by a variety of mechanisms. With increasing velocity, they produce light by catalysis of baryon decay, luminescence in the ice associated with electronic excitations, indirect and direct Cherenkov light from the monopole track, and Cherenkov light from cascades induced by pair creation and photonuclear reactions. By searching for this light, current best limits for the monopole flux over a broad range of velocities was achieved using the IceCube detector. A review of these magnetic monopole searches is presented.

  16. Dipole strength distribution below the giant dipole resonance in {sup 92}Mo, {sup 98}Mo and {sup 100}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Rusev, G.Y.

    2006-07-01

    Investigations of the dipole-strength distributions in {sup 92}Mo, {sup 98}Mo and {sup 100}Mo were carried out by means of the method of nuclear resonance fluorescence. The low-lying excitations in the nuclides {sup 92}Mo, {sup 98}Mo and {sup 100}Mo have been studied in photon-scattering experiments at an electron energy of 6 MeV at the ELBE accelerator and at electron energies from 3.2 to 3.8 MeV at the Dynamitron accelerator. Five levels were observed in {sup 92}Mo. Five levels in {sup 98}Mo and 14 in {sup 100}Mo were identified for the first time in the energy range from 2 to 4 MeV. Dipole-strength distributions up to the neutron-separation energies in the nuclides {sup 92}Mo, {sup 98}Mo and {sup 100}Mo have been investigated at the ELBE accelerator. Because of the possible observation of transitions in the neighboring nuclei produced via ({gamma},n) reaction, additional measurements at electron energies of 8.4 and 7.8 MeV, below the neutron-separation energy, were performed on {sup 98}Mo and {sup 100}Mo, respectively. The number of transitions assigned to {sup 92}Mo, {sup 98}Mo and {sup 100}Mo is 340, 485 and 499, respectively, the main part of them being dipole transitions. Statistical properties of the observed transitions are obtained. The continuum contains the ground-state transitions as well as the branching transitions to the low-lying levels and the subsequent deexcitations of these levels. (orig.)

  17. Study of isovector resonances with pion charge exchange

    International Nuclear Information System (INIS)

    Baer, H.W.; Bolton, R.; Bowman, J.D.

    1982-01-01

    Studies with the pion charge exchange reactions (π/sup +-/,π 0 ) at 164 MeV using the LAMPF π 0 spectrometer are yielding new results on the existence and systematic features of isovector resonances in nuclei. These experiments possess an unusually high signal/background ratio for isovector resonances of low-multipolarity. Results obtained to date are: (1) observation and angular disribution measurement of the giant dipole resonance in nuclei 12 C, 40 Ca, 90 Zr, and 120 Sn; and (2) observation and angular distribution measurements in the (π - ,π 0 ) reaction on 90 Zr and 120 Sn of large signals possessing the expected angular distribution shapes and magnitudes for the isovector monopole resonance. Excitation energies are near the hydrodynamical model values 170 A - /sup 1/3/ MeV. Differential cross sections are approximately 0.7 J 1 2 (qR) mb/sr. An overview of this experimental program, with emphasis on new results and how they correlate with existing knowledge on the isovector resonances, is presented

  18. Grassmann's fields and generalized magnetic monopoles

    International Nuclear Information System (INIS)

    Maia Junior, A.; Rodrigues Junior, W.A.

    1989-01-01

    We present a theory of dual charges with the introduction of a generalized potential and a generalized field are locally respectively elements of the odd and even parts of the Grassmann algebra of space-time, with values in the Lie algebra of a gauge group G. Defining a generalized Dirac operator and its dual, we get the field equations of the theory. When G = U(1) we obtain a theory of electrodynamics with magnetic monopoles without string. We show that the generalized field is invariant under harmonic gauge transformations and we obtain Dirac's quantization condition for the dual charges. (author) [pt

  19. Magnetic monopoles and dyons interacting with matter

    International Nuclear Information System (INIS)

    Bracci, L.

    1985-01-01

    After a brief, critical review of the Drell et al. method, we propose an alternative approach suitable for the study of dyon and dyon-negative-electron (Dy-e) system interactions with hydrogen and helium. This method, called the impact parameter method (IPM), has been used already in atomic collisions and allows the calculation of energy losses in H and He. We report these quantities and comment on their behaviour versus the relative velocities between Dy or Dy-e and atoms; we compare them to the monopole results. Conclusions in relation to planned experiments are outlined. (orig.)

  20. Gauge-fixing ambiguity and monopole number

    International Nuclear Information System (INIS)

    Hioki, S.; Miyamura, O.

    1991-01-01

    Gauge-fixing ambiguities of lattice SU(2) QCD are studied in the maximally abelian and unitary gauges. In the former, we find local maxima of a gauge-fixing function which may correspond to Gribov copies. There is a definite anti-correlation between the number of monopoles and the value of the function. Errors of measured quantities coming from the ambiguity are found to be less than inherent dispersion in the ensemble average. No ambiguity is found in the unitary gauges. (orig.)

  1. Non-minimal Wu-Yang monopole

    International Nuclear Information System (INIS)

    Balakin, A.B.; Zayats, A.E.

    2007-01-01

    We discuss new exact spherically symmetric static solutions to non-minimally extended Einstein-Yang-Mills equations. The obtained solution to the Yang-Mills subsystem is interpreted as a non-minimal Wu-Yang monopole solution. We focus on the analysis of two classes of the exact solutions to the gravitational field equations. Solutions of the first class belong to the Reissner-Nordstroem type, i.e., they are characterized by horizons and by the singularity at the point of origin. The solutions of the second class are regular ones. The horizons and singularities of a new type, the non-minimal ones, are indicated

  2. Searches for magnetic monopoles with IceCube

    Science.gov (United States)

    Pollmann, Anna

    2018-01-01

    Particles that carry a magnetic monopole charge are proposed by various theories which go beyond the Standard Model of particle physics. The expected mass of magnetic monopoles varies depending on the theory describing its origin, generally the monopole mass far exceeds those which can be created at accelerators. Magnetic monopoles gain kinetic energy in large scale galactic magnetic fields and, depending on their mass, can obtain relativistic velocities. IceCube is a high energy neutrino detector using the clear ice at the South Pole as a detection medium. As monopoles pass through this ice they produce optical light by a variety of mechanisms. With increasing velocity, they produce light by catalysis of baryon decay, luminescence in the ice associated with electronic excitations, indirect and direct Cherenkov light from the monopole track, and Cherenkov light from cascades induced by pair creation and photonuclear reactions. By searching for this light, current best limits for the monopole flux over a broad range of velocities was achieved using the IceCube detector. A review of these magnetic monopole searches is presented.

  3. Microflown based monopole sound sources for reciprocal measurements

    NARCIS (Netherlands)

    Bree, H.E. de; Basten, T.G.H.

    2008-01-01

    Monopole sound sources (i.e. omni directional sound sources with a known volume velocity) are essential for reciprocal measurements used in vehicle interior panel noise contribution analysis. Until recently, these monopole sound sources use a sound pressure transducer sensor as a reference sensor. A

  4. Informational economy: specific features and challenges of monopolization

    OpenAIRE

    Kotsofana, T.

    2013-01-01

    The article discusses the features of the informational economy, as well as some issues with which this economy is facing today. In particular, contemporary forms of monopoly, its causes and consequences, changing trends towards monopolization and monopolization of markets due to the high degree of automation and information of the socio-economic life were analyzed.

  5. Relations between grand unified and monopole theories

    International Nuclear Information System (INIS)

    Olive, D.I.

    1983-01-01

    Two kinds of interrelationships between GUTs and monopole theories are discussed: how the duality conjectures could have a bearing on understanding GUTs, and how some of the mathematical technology used in monopole studies can yield simple (Dynkin) diagrammatic rules for some of the common GUT group theory calculations. A compact notation for semisimple Lie algebras is supplied by Dynkin diagrams. Minimal fundamental weights are seen to define minimal representations into which matter may be placed, and also define a special direction for the adjoint Higgs field. Minimal weights play a special role, therefore, both in defining matter multiplets and in symmetry breaking. After considering gauge groups G broken down to U(1) X K/Z (with K semisimple) by an adjoint representation (AR) Higgs, it is asked how the representations of G will look when decomposed into irreducible representations of U(1) X K, by proving two theorems as given. The point is pedagogical: using concepts like the Weyl group, practical calculations can be performed with simple Dynkin diagrams

  6. Electric Monopole Transition Strengths in 62Ni

    Directory of Open Access Journals (Sweden)

    Evitts L. J.

    2016-01-01

    Full Text Available Excited states in 62Ni were populated with a (p, p’ reaction using the 14UD Pelletron accelerator at the Australian National University. Electric monopole transition strengths, ρ2(E0, were measured through simultaneous detection of the internal conversion electrons and γ rays emitted from the de-excitation of populated states, using the Super-e spectrometer coupled with a germanium detector. The strength of the 02+ to 01+ transition has been measured to be 77−34+23 × 10−3 and agrees with previously reported values. Upper limits have been placed on the 03+ to 01+ and 03+ to 02+ transitions. The measured ρ2(E0 value of the 22+ to 21+ transition in 62Ni has been measured for the first time and found to be one of the largest ρ2(E0 values measured to date in nuclei heavier than Ca. The low-lying states of 62Ni have previously been classified as one- and two-phonon vibrational states based on level energies. The measured electric quadrupole transition strengths are consistent with this interpretation. However as electric monopole transitions are forbidden between states which differ by one phonon number, the simple harmonic quadrupole vibrational picture is not suffcient to explain the large ρ2(E0 value for the 22+ to 21+ transition.

  7. Electric Monopole Transition Strengths in 62Ni

    Science.gov (United States)

    Evitts, L. J.; Garnsworthy, A. B.; Kibédi, T.; Moukaddam, M.; Alshahrani, B.; Eriksen, T. K.; Holt, J. D.; Hota, S. S.; Lane, G. J.; Lee, B. Q.; McCormick, B. P.; Palalani, N.; Reed, M. W.; Stroberg, S. R.; Stuchbery, A. E.

    2016-09-01

    Excited states in 62Ni were populated with a (p, p') reaction using the 14UD Pelletron accelerator at the Australian National University. Electric monopole transition strengths, ρ2(E0), were measured through simultaneous detection of the internal conversion electrons and γ rays emitted from the de-excitation of populated states, using the Super-e spectrometer coupled with a germanium detector. The strength of the 02+ to 01+ transition has been measured to be 77-34+23 × 10-3 and agrees with previously reported values. Upper limits have been placed on the 03+ to 01+ and 03+ to 02+ transitions. The measured ρ2(E0) value of the 22+ to 21+ transition in 62Ni has been measured for the first time and found to be one of the largest ρ2(E0) values measured to date in nuclei heavier than Ca. The low-lying states of 62Ni have previously been classified as one- and two-phonon vibrational states based on level energies. The measured electric quadrupole transition strengths are consistent with this interpretation. However as electric monopole transitions are forbidden between states which differ by one phonon number, the simple harmonic quadrupole vibrational picture is not suffcient to explain the large ρ2(E0) value for the 22+ to 21+ transition.

  8. X-ray excited photoluminescence near the giant resonance in solid-solution Gd1-xTbxOCl nanocrystals and their retention upon solvothermal topotactic transformation to Gd1-xTbxF3

    Science.gov (United States)

    Waetzig, Gregory R.; Horrocks, Gregory A.; Jude, Joshua W.; Zuin, Lucia; Banerjee, Sarbajit

    2015-12-01

    Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb3+ centers upon excitation in proximity to the giant resonance of the host Gd3+ ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism from multiple exciton generation to single thermal exciton formation and Auger decay processes. The solid-solution Gd1-xTbxOCl nanocrystals are further topotactically transformed with retention of a nine-coordinated cation environment to solid-solution Gd1-xTbxF3 nanocrystals upon solvothermal treatment with XeF2. The metastable hexagonal phase of GdF3 can be stabilized at room temperature through this topotactic approach and is transformed subsequently to the orthorhombic phase. The fluoride nanocrystals indicate an analogous but blue-shifted modulation of the X-ray excited optical luminescence of the Tb3+ centers upon X-ray excitation near the giant resonance of the host Gd3+ ions.Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb3+ centers upon excitation in proximity to the giant resonance of the host Gd3+ ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism

  9. Relation of photofission cross sections and delayed neutron photoproduction in the range of E1-giant resonance. Sootnoshenie mezhdu secheniyami fotodeleniya i fotoobrazovaniya zapazdyvayushchikh nejtronov v oblasti E1-gigantskogo rezonansa

    Energy Technology Data Exchange (ETDEWEB)

    Ganich, P P; Parlag, O A; Sikora, D I; Sychev, S I

    1989-03-01

    Relation between yields and cross sections of photofission and photoproduction is studied in order to use them in the methods for analysis of fissile nuclides. Total yield of delayed neutrons from the {sup 232}Th target and ratios of total yields from {sup 238}U and {sup 232}Th targets were measured in the M=300 microtron in 6-18 MeV energy range. Efficiency of the suggested method for refining the {sup 238}U photofission cross sections in the range of E1-giant resonance is shown.

  10. Giant resonance spectroscopy of 40Ca with the (e,e'x) reaction (II): Multipole decomposition of 4π-integrated spectra and angular correlations

    International Nuclear Information System (INIS)

    Diesener, H.; Helm, U.; Huck, V.; Neumann-Cosel, P. von; Rangacharyulu, C.; Richter, A.; Schrieder, G.; Stascheck, A.; Strauch, S.; Ryckebusch, J.; Carter, J.

    2001-01-01

    The present article is the second out of three on a study of the 40 Ca(e,e'x) reaction discussing the multipole decomposition of the measured cross sections and the analysis of angular correlations. The decomposition of the strongly overlapping E0, E1 and E2 giant resonance strengths using the (e,e'x; x=p,α) reaction in 40 Ca is discussed for excitation energies between 10 and about 21 MeV. Two extraction methods are presented based on the variation of the form factors for the different multipoles. The resulting B(E1) strength distribution is in good agreement with (γ,x) photoabsorption data. The summed B(E2) and B(E0) strength is highly fragmented and spread out over the energy region investigated. Microscopic continuum RPA calculations including the coupling of the basic particle-hole states to the low-lying surface vibrations are capable of reproducing the strength distributions quite accurately. Exhaustion of the energy-weighted sum rules (EWSR) for the various decay channels is presented. A complete decomposition of E0, E1 and E2 contributions in 40 Ca is possible for (e,e'α) angular correlations populating the 36 Ar ground state. Contrary to expectations, the form factors of isoscalar E0 and E2 strengths in the 40 Ca(e,e'α 0 ) reaction exhibit increasing differences towards smaller momentum transfers. Angular correlations for proton decay into low-lying states of 39 K are compared to a self-consistent continuum RPA calculation which allows a systematic description of the strong variations observed as a function of 40 Ca excitation energy and momentum transfer. The success implies that direct knock-out models of the 40 Ca(e,e'p) reaction are too simple. Furthermore, the shapes of the angular correlations seem to be determined largely by the final-state interaction, in particular by charge exchange reactions in the nuclear medium

  11. Resonance

    DEFF Research Database (Denmark)

    Petersen, Nils Holger

    2014-01-01

    A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice.......A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice....

  12. On a Painleve test for the complete integrability of Bogomolny's monopole equation

    International Nuclear Information System (INIS)

    Roy Chowdhury, A.; Chanda, P.K.

    1984-09-01

    We have made an analysis of the monopole equation of Bogomolny from the stand point of Painleve test. The idea that any non-linear partial differential equation admitting a Lax representation should conform to the criterion of the Painleve analysis seems to hold well in case of Bogomolny equation. We have determined the position for resonances and have proved that at each of these the coefficients in the Forbenius type expansion of the gauge potentials do become arbitrary signalling the complete integrability of the system. (author)

  13. A compact planar multi-broad band monopole antenna for mobile devices

    Science.gov (United States)

    Zhong, Xiaoqing; Yao, Bin; Zheng, Qinhong; Yang, Jikong; Cao, Xiangqi

    2015-10-01

    A Multiple-frequency broadband planar monopole antenna is proposed in this Paper. The antenna is stimulated and numerically optimized by HFSS13.0 (High Frequency Structure Simulator). The size of it is 39mm×22mm×1.7mm. The antenna resonates at many frequencies. The parameter S112G(DCS1800 and PCS1900), 3G(UMTS), 4G(LTE2300 and LTE2500), ISM, WLAN. It is quiet appropriate for the present ultra-thin smart phones

  14. Giant cystic craniopharyngiomas

    International Nuclear Information System (INIS)

    Young, S.C.; Zimmerman, R.A.; Nowell, M.A.; Bilaniuk, L.T.; Hackney, D.B.; Grossman, R.I.; Goldberg, H.I.

    1987-01-01

    Three cases of giant cystic craniopharyngiomas with large areas of extension beyond the suprasellar area are presented. The magnetic resonance (MR) appearance in one case is described. These giant tumors had large, multilobulated cysts that comprised the bulk of the tumors. In one case, there was an unusual extension of the large tumor cyst into the lateral ventricle. In two cases, the tumors extended to the level of the foramen magnum. On CT, the cyst contents of these two tumors were hyperdense and became hypodense postoperatively. All three tumors harbored calcifications in the form of clumps in the suprasellar region and rim calcifications around the cysts. None of the tumors exhibited contrast enhancement. A literature review of the radiographic features of craniopharyngiomas is discussed. (orig.)

  15. A steady state tokamak operation by use of magnetic monopoles

    International Nuclear Information System (INIS)

    Narihara, K.

    1991-12-01

    A steady state tokamak operation based on a magnetic monopole circuit is considered. Circulation of a chain of iron cubes which trap magnetic monopoles generates the needed loop voltage. The monopole circuit is enclosed by a series of solenoid coils in which magnetic field is feedback controlled so that the force on the circuit balance against the mechanical friction. The driving power is supplied through the current sources of poloidal, ohmic and solenoid coils. The current drive efficiency is same as that of the ohmic current drive. (author)

  16. Parker limit for monopoles with large magnetic charge

    International Nuclear Information System (INIS)

    Hodges, H.M.; Kolb, E.W.; Turner, M.S.

    1986-01-01

    The survival of galactic magnetic fields places a limit on the flux of magnetic monopoles, the so-called ''Parker limit.'' Previous discussions of the Parker limit have assumed that the charge of the monopole is the Dirac value, g/sub Dirac/ = 2π/e. However, if the grand unified group is broken by Wilson lines, as is assumed in some superstring models, the minimum value of the magnetic charge is not the Dirac quantum, but an integer multiple of it. In this brief report we investigate the dependence of the Parker limit on the charge of the magnetic monopole. 10 refs., 1 fig

  17. Electric fields and monopole currents in compact QED

    International Nuclear Information System (INIS)

    Zach, M.; Faber, M.; Kainz, W.; Skala, P.

    1995-01-01

    The confinement in compact QED is known to be related to magnetic monopoles. Magnetic currents form a solenoid around electric flux lines between a pair of electric charges. This behaviour can be described by the dual version of Maxwell-London equations including a fluctuating string. We use a definition of magnetic monopole currents adjusted to the definition of the electric field strength on a lattice and get good agreement for field and current distributions between compact QED and the predictions of dual Maxwell-London equations. Further we show that the monopole fluctuations in the vacuum are suppressed by the flux tube. ((orig.))

  18. Scheme for Building a 't Hooft-Polyakov Monopole

    International Nuclear Information System (INIS)

    Sonner, Julian; Tong, David

    2009-01-01

    We study a simple quantum mechanical model of a spinning particle moving on a sphere in the presence of a magnetic field. The system has two ground states. As the magnetic field is varied, the ground states mix through a non-Abelian Berry phase. We show that this Berry phase is the path ordered exponential of the smooth SU(2)'t Hooft-Polyakov monopole. We further show that, by adjusting a potential on the sphere, the monopole becomes a Bogomol'nyi-Prasad-Sommerfield monopole and obeys the Bogomol'nyi equations.

  19. Stable monopole-antimonopole string background in SU(2) QCD

    International Nuclear Information System (INIS)

    Cho, Y.M.; Pak, D.G.

    2006-01-01

    Motivated by the instability of the Savvidy-Nielsen-Olesen (SNO) vacuum we make a systematic search for a stable magnetic background in pure SU(2) QCD. It is shown that a pair of axially symmetric monopole and antimonopole strings is stable, provided that the distance between the two strings is less than a critical value. The existence of a stable monopole-antimonopole string background strongly supports that a magnetic condensation of monopole-antimonopole pairs can generate a dynamical symmetry breaking, and thus the magnetic confinement of color in QCD

  20. A search for magnetic monopoles with the Soudan 2 detector

    International Nuclear Information System (INIS)

    Allison, W.W.M.; Barr, G.D.; Brooks, C.B.; Cobb, J.H.; Kirby-Gallagher, L.M.; Giles, R.H.; Giller, G.L.; Perkins, D.H.; Shield, P.D.; Thomson, M.A.; West, N.; Alner, G.J.; Cockerill, D.J.A.; Edwards, V.W.; Garcia-Garcia, C.; Litchfield, P.J.; Pearce, G.F.; Woods, C.A.; Ambats, I.; Ayres, D.S.; Balka, L.; Barrett, W.L.; Dawson, J.; Fields, T.; Goodman, M.C.; Heilig, S.J.; Hill, N.; Jankowski, D.J.; Lopez, F.; May, E.N.; Price, L.E.; Schlereth, J.; Thron, J.L.; Border, P.; Courant, H.; Dahlin, B.; Demuth, D.; Gray, R.; Heppelmann, S.; Johns, K.; Joyce, T.; Kasahara, S.; Longley, N.; Lowe, M.; Marshak, M.L.; Miller, W.H.; Minor, C.; Peterson, E.A.; Roback, D.; Rosen, D.; Ruddick, K.; Schmid, D.; Shupe, M.; Villaume, G.; Weems, L.; Werkema, S.J.

    1991-08-01

    A search for GUT magnetic monopoles has been conducted using the Soudan 2 nucleon decay detector. This detector is a fine-grained tracking calorimeter. Monopole candidates were selected on the basis of significantly higher ionization than throughgoing cosmic ray muons. Preliminary results, using data taken over approximately one year with no monopoles observed, correspond to a flux limit of 2.4 10 -14 cm -2 sr -1 s -1 over a velocity range of 10 -3 < β < 0.95. 8 refs

  1. Suppressing the QCD axion abundance by hidden monopoles

    International Nuclear Information System (INIS)

    Kawasaki, Masahiro

    2015-11-01

    We study the Witten effect of hidden monopoles on the QCD axion dynamics, and show that its abundance as well as isocurvature perturbations can be significantly suppressed if there is a sufficient amount of hidden monopoles. When the hidden monopoles make up a significant fraction of dark matter, the Witten effect suppresses the abundance of axion with the decay constant smaller than 10 12 GeV. The cosmological domain wall problem of the QCD axion can also be avoided, relaxing the upper bound on the decay constant when the Peccei-Quinn symmetry is spontaneously broken after inflation.

  2. Vacuum-polarization effects in global monopole space-times

    International Nuclear Information System (INIS)

    Mazzitelli, F.D.; Lousto, C.O.

    1991-01-01

    The gravitational effect produced by a global monopole may be approximated by a solid deficit angle. As a consequence, the energy-momentum tensor of a quantum field will have a nonzero vacuum expectation value. Here we study this ''vacuum-polarization effect'' around the monopole. We find explicit expressions for both left-angle φ 2 right-angle ren and left-angle T μν right-angle ren for a massless scalar field. The back reaction of the quantum field on the monopole metric is also investigated

  3. The global monopole spacetime and its topological charge

    Science.gov (United States)

    Tan, Hongwei; Yang, Jinbo; Zhang, Jingyi; He, Tangmei

    2018-03-01

    We show that the global monopole spacetime is one of the exact solutions of the Einstein equations by treating the matter field as a non-linear sigma model, without the weak field approximation applied in the original derivation by Barriola and Vilenkin. Furthermore, we find the physical origin of the topological charge in the global monopole spacetime. Finally, we generalize the proposal which generates spacetime from thermodynamical laws to the case of spacetime with global monopole charge. Project supported by the National Natural Science Foundation of China (Grant Nos. 11273009 and 11303006).

  4. Lagrangian Curves on Spectral Curves of Monopoles

    International Nuclear Information System (INIS)

    Guilfoyle, Brendan; Khalid, Madeeha; Ramon Mari, Jose J.

    2010-01-01

    We study Lagrangian points on smooth holomorphic curves in TP 1 equipped with a natural neutral Kaehler structure, and prove that they must form real curves. By virtue of the identification of TP 1 with the space LE 3 of oriented affine lines in Euclidean 3-space, these Lagrangian curves give rise to ruled surfaces in E 3 , which we prove have zero Gauss curvature. Each ruled surface is shown to be the tangent lines to a curve in E 3 , called the edge of regression of the ruled surface. We give an alternative characterization of these curves as the points in E 3 where the number of oriented lines in the complex curve Σ that pass through the point is less than the degree of Σ. We then apply these results to the spectral curves of certain monopoles and construct the ruled surfaces and edges of regression generated by the Lagrangian curves.

  5. Magnetic monopoles near the black hole threshold

    International Nuclear Information System (INIS)

    Lue, A.; Weinberg, E.J.

    1999-01-01

    We present new analytic and numerical results for self-gravitating SU(2)-Higgs magnetic monopoles approaching the black hole threshold. Our investigation extends to large Higgs self-coupling, λ, a regime heretofore unexplored. When λ is small, the critical solution where a horizon first appears is extremal Reissner-Nordstroem outside the horizon but has a nonsingular interior. When λ is large, the critical solution is an extremal black hole with non-Abelian hair and a mass less than the extremal Reissner-Nordstroem value. The transition between these two regimes is reminiscent of a first-order phase transition. We analyze in detail the approach to these critical solutions as the Higgs expectation value is varied, and compare this analysis with the numerical results. copyright 1999 The American Physical Society

  6. A non-Abelian SO(8) monopole as generalization of Dirac-Yang monopoles for a 9-dimensional space

    International Nuclear Information System (INIS)

    Le, Van-Hoang; Nguyen, Thanh-Son

    2011-01-01

    We establish an explicit form of a non-Abelian SO(8) monopole in a 9-dimensional space and show that it is indeed a direct generalization of Dirac and Yang monopoles. Using the generalized Hurwitz transformation, we have found a connection between a 16-dimensional harmonic oscillator and a 9-dimensional hydrogenlike atom in the field of the SO(8) monopole (MICZ-Kepler problem). Using the built connection the group of dynamical symmetry of the 9-dimensional MICZ-Kepler problem is found as SO(10, 2).

  7. Magnetic monopoles without strings by Kaehler-Clifford algebra

    International Nuclear Information System (INIS)

    Maia, A. Jr.; Recami, E.; Rodrigues, W.A. Jr.; Rosa, M.A.F.

    1990-01-01

    In place of Dirac monopoles with string, this paper presents monopoles without string on the basis of a generalized potential, the sum of a vector A and a pseudovector γB potential. By having recourse to the (graded) Clifford algebra which allows adding together tensors of different ranks (e.g., scalars + pseudoscalars + vectors + pseudovectors + . . .), in a previous paper we succeeded in constructing a Lagrangian and Hamiltonian formalism for interacting monopoles that can be regarded as satisfactory from various points of view. In the present note, after having completed that formalism, the authors put forth a purely geometrical interpretation of it within the Kahler algebra on differential forms, essential ingredients being the natural introduction of a generalized curvature and the Hodge decomposition. The authors thus pave the way for the extension of monopoles without string to non-abelian gauge groups. The analogies of this approach with supersymmetric theories are apparent

  8. New approaches for searching for the Dirac magnetic monopole

    International Nuclear Information System (INIS)

    Kukhtin, V.V.; Krivokhizhin, V.G.; Stetsenko, S.G.; Cheplakov, A.P.

    2012-01-01

    Three new approaches, not applied earlier, are proposed to search for the Dirac monopole - an object whose existence was proposed by P.Dirac more than 80 years ago to explain the electrical charge quantization. The first approach assumes that the monopole must be accelerated by a magnetic field, and such acceleration is constant in the magnetic field which is homogeneous and constant. The conclusion about the object movement nature can be drawn by measuring the time marks for equidistant registering planes. The second approach is supposed to reconstruct the movement trajectory in the homogeneous and permanent electrical field, which is the circle or its part for the magnetic monopole. The third approach is based on the constancy of energy losses by Dirac monopole due to medium ionization in the multilayer passive dielectric tracking detectors placed in the homogeneous and permanent electrical field

  9. Evaluation of substitution monopole models for tire noise sound synthesis

    Science.gov (United States)

    Berckmans, D.; Kindt, P.; Sas, P.; Desmet, W.

    2010-01-01

    Due to the considerable efforts in engine noise reduction, tire noise has become one of the major sources of passenger car noise nowadays and the demand for accurate prediction models is high. A rolling tire is therefore experimentally characterized by means of the substitution monopole technique, suiting a general sound synthesis approach with a focus on perceived sound quality. The running tire is substituted by a monopole distribution covering the static tire. All monopoles have mutual phase relationships and a well-defined volume velocity distribution which is derived by means of the airborne source quantification technique; i.e. by combining static transfer function measurements with operating indicator pressure measurements close to the rolling tire. Models with varying numbers/locations of monopoles are discussed and the application of different regularization techniques is evaluated.

  10. Dirac's Dream - the Search for the Magnetic Monopole

    International Nuclear Information System (INIS)

    Pinfold, James L.

    2010-01-01

    I first quickly summarize the history of the Magnetic Monopole leading to the quantum theory of magnetic charge that started with a 1931 paper by Paul Dirac who showed that the existence of magnetic monopoles was consistent with Maxwell's equations only if electric charges are quantized. Next I will briefly review the status of monopole searches. Last, but not least I discuss in more detail the MoEDAL experiment--the latest accelerator experiment designed to search for direct production of magnetic monopoles or dyons (particles with electric and magnetic charge) and other highly ionizing particles - such as heavy (pseudo-) stable particles with conventional electric charge - at the LHC. The MoEDAL experiment employs nuclear track-etch detectors deployed in the VELO vertex region of the LHCb experiment.

  11. Magnetic Monopoles, Center Vortices and Topology of Gauge Fields

    OpenAIRE

    Reinhardt, H.; Engelhardt, M.; Langfeld, K.; Quandt, M.; Schafke, A.

    1999-01-01

    The topological properties of magnetic monopoles and center vortices arising, respectively, in Abelian and center gauges are studied in continuum Yang-Mills Theory. For this purpose the continuum analog of the maximum center gauge is constructed.

  12. Magnetic monopoles, center vortices and topology of gauge fields

    International Nuclear Information System (INIS)

    Reinhardt, H.; Engelhardt, M.; Langfeld, K.; Quandt, M.; Schaefke, A.

    2000-01-01

    The topological properties of magnetic monopoles and center vortices arising, respectively, in Abelian and center gauges are studied in continuum Yang-Mills Theory. For this purpose the continuum analog of the maximum center gauge is constructed

  13. On the primordial monopole problem in grand unified theories

    International Nuclear Information System (INIS)

    Salomonson, P.; Stern, A.; Skagerstam, B.S.

    1984-11-01

    It is shown that spontaneously broken gauge symmetries are not necessarily restored at very high temperatures in which case an unacceptably large production of magnetic monopoles may be prohibited. (orig.)

  14. Physico mathematical approach to generalized monopoles without a string

    International Nuclear Information System (INIS)

    Rodrigues, W.A.; Faria Rosa, M.A.; Maia, A.

    1988-01-01

    A theory of the generalized magnetic monopole without string, which is distinct from Dirac's original theory and also distinct from the topological theory of the monopole is presented. This theory is first formulated in the Clifford bundle formalism; and in the particular case of electrodynamics it is deduced from Maxwell equations the generalized Lorentz force and the equations of motion of charges and monopoles. The conservation laws and the problem of Lagrangian formalism are discussed. Dirac quantization condition in two different ways are obtained. Finally a principal fiber formulation of the theory using the spliced bundle concept with gauge group GxG, where G is the gauge group of the theory without monopoles, is presented

  15. Mathematical physics of the generalized monopole without string

    International Nuclear Information System (INIS)

    Rodrigues Junior, W.A.; Rosa, M.A.F.; Maia Junior, A.; Recami, E.

    1988-01-01

    In this paper we present a theory of the generalized magnetic monopole without string, which is distinct from Dirac's original theory and distinct from the topological theory of the monopole. Our theory is first formulated in the Clifford bundle formalism; and in the particular case of electrodynamics we deduce from Maxwell equations the generalized Lorentz force and the equations of motion of charges and monopoles. We discuss the conservation laws and the problem of the Lagrangian formalism. We obtain Dirac quantization condition in two different ways. Finally, we present a principal fiber bundle formulation of our theory using the spliced-bundle concept with gauge group GxG, where G is the gauge group of the theory without monopoles. (author) [pt

  16. Giant Chancroid

    Directory of Open Access Journals (Sweden)

    Bhushan Kumar

    1980-01-01

    Full Text Available A case of giant chancroid following rupture of inguinal bubo and having systemic symptoms is described. Response with sulfa and streptomycin combination was excellent and the lesion healed completely in 3 weeks. Early diagnosis and treatment of chancroid will prevent this debilitating complication.

  17. Giant microelectronics

    International Nuclear Information System (INIS)

    Della Sala, D.; Privato, C.; Di Lazzaro, P.; Fortunato, G.

    1999-01-01

    Giant microelectronics, on which the technology of flat liquid-crystal screens is based, is an example of fruitful interaction among independently-developed technologies, in this case thin film micro devices and laser applications. It typifies the interdisciplinary approach needed to produce innovations in microelectronics [it

  18. Magnetic monopole and finite photon mass: are they compatible?

    International Nuclear Information System (INIS)

    Ignatiev, A.Y.; Joshi, G.C.

    1994-01-01

    The role played by the gauge invariance for the existence of Dirac monopole is analysed. It is shown that the derivation of the Dirac quantization condition based on the angular momentum algebra cannot be generalized to the case of massive electrodynamics. The work revealed a new and important relation between the two fundamental facts: the masslessness (massiveness?) of the photons and the non-existence (existence?) of the magnetic monopole. Possible implications of this result are briefly discussed. 12 refs

  19. 8D oscillator as a hidden SU(2)-monopole

    International Nuclear Information System (INIS)

    Mardoyan, L.G.; Sisakyan, A.N.; Ter-Antonyan, V.M.

    1998-01-01

    In the framework of an analytical approach and with the help of the generalized version of the Hurwitz transformation the five-dimensional SU(2)-monopole model is constructed from the eight-dimensional quantum oscillator. The Clebsch-Gordan expansion stimulated by the space-gauge coupling, the hyperangle and the radial parts of the total wave function, the energy spectrum of the charge-monopole bound system and the corresponding degeneracy are calculated

  20. Properties of global monopoles with an event horizon

    OpenAIRE

    Tamaki, T; Sakai, N

    2004-01-01

    We investigate the properties of global monopoles with an event horizon. We find that there is an unstable circular orbit even if a particle does not have an angular momentum when the core mass is negative. We also obtain the asymptotic form of solutions when the event horizon is much larger than the core radius of the monopole, and discuss if they could be a model of galactic halos.

  1. Magnetic monopole solution in non-Abelian gauge theory

    International Nuclear Information System (INIS)

    Hietarinta, J.; Takasugi, E.; Tanaka, K.

    1976-01-01

    An approximate analytic solution of the equations of motion of the 't Hooft magnetic monopole model is proposed. Virial type global tests are carried out for the solution. Then, the monopole mass, energies of the vector field A/sub mu/sup a/, Higgs field phi/sup a/ and interaction are computed in closed form. The form factors of A/sub i/sup a/ and phi/sup a/ in a quantized version are also calculated

  2. Monopole-fermion systems in the complex isotropic tetrad formalism

    International Nuclear Information System (INIS)

    Gal'tsov, D.V.; Ershov, A.A.

    1988-01-01

    The interaction of fermions of arbitrary isospin with regular magnetic monopoles and dyons of the group SU(2) and also with point gravitating monopoles and dyons of the Wu-Yang type described by the Reissner-Nordstrom metric are studied using the Newman-Penrose complex isotropic tetrad formalism. Formulas for the bound-state spectrum and explicit expressions for the zero modes are obtained and the Rubakov-Callan effect for black holes is discussed

  3. Searches for relativistic magnetic monopoles in IceCube

    Energy Technology Data Exchange (ETDEWEB)

    Aartsen, M.G.; Hill, G.C.; Robertson, S.; Wallace, A.; Whelan, B.J. [University of Adelaide, Department of Physics, Adelaide (Australia); Abraham, K.; Bernhard, A.; Coenders, S.; Gross, A.; Holzapfel, K.; Huber, M.; Jurkovic, M.; Krings, K.; Resconi, E.; Turcati, A.; Veenkamp, J. [Technische Universitaet Muenchen, Garching (Germany); Ackermann, M.; Berghaus, P.; Bernardini, E.; Bretz, H.P.; Cruz Silva, A.H.; Gluesenkamp, T.; Gora, D.; Jacobi, E.; Karg, T.; Middell, E.; Mohrmann, L.; Nahnhauer, R.; Schoenwald, A.; Spiering, C.; Stasik, A.; Stoessl, A.; Strotjohann, N.L.; Terliuk, A.; Usner, M.; Santen, J. van; Yanez, J.P. [DESY, Zeuthen (Germany); Adams, J. [University of Canterbury, Department of Physics and Astronomy, Christchurch (New Zealand); Aguilar, J.A.; Ansseau, I.; Heereman, D.; Meagher, K.; Meures, T.; O' Murchadha, A.; Pinat, E.; Raab, C. [Universite Libre de Bruxelles, Brussels (Belgium); Ahlers, M.; Arguelles, C.; Beiser, E.; Braun, J.; Chirkin, D.; Day, M.; Desiati, P.; Diaz-Velez, J.C.; Fahey, S.; Feintzeig, J.; Ghorbani, K.; Gladstone, L.; Griffith, Z.; Halzen, F.; Hanson, K.; Hoshina, K.; Jero, K.; Karle, A.; Kelley, J.L.; Kheirandish, A.; McNally, F.; Merino, G.; Morse, R.; Richter, S.; Sabbatini, L.; Tobin, M.N.; Tosi, D.; Vandenbroucke, J.; Wandkowsky, N.; Wendt, C.; Westerhoff, S.; Wille, L.; Xu, D.L. [University of Wisconsin, Department of Physics and Wisconsin IceCube Particle Astrophysics Center, Madison, WI (United States); Ahrens, M.; Bohm, C.; Dumm, J.P.; Finley, C.; Flis, S.; Hulth, P.O.; Hultqvist, K.; Walck, C.; Wolf, M.; Zoll, M. [Stockholm University, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Altmann, D.; Classen, L.; Kappes, A.; Tselengidou, M. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erlangen (Germany); Anderson, T.; Arlen, T.C.; Dunkman, M.; Huang, F.; Keivani, A.; Lanfranchi, J.L.; Pankova, D.V.; Quinnan, M.; Tesic, G. [Pennsylvania State University, Department of Physics, University Park, PA (United States); Archinger, M.; Baum, V.; Boeser, S.; Del Pino Rosendo, E.; Di Lorenzo, V.; Eberhardt, B.; Ehrhardt, T.; Foesig, C.C.; Koepke, L.; Kroll, G.; Krueckl, G.; Sander, H.G.; Sandroos, J.; Schatto, K.; Steuer, A.; Wiebe, K. [University of Mainz, Institute of Physics, Mainz (Germany); Auffenberg, J.; Bissok, M.; Blumenthal, J.; Gier, D.; Glagla, M.; Haack, C.; Hansmann, B.; Kemp, J.; Konietz, R.; Leuermann, M.; Leuner, J.; Paul, L.; Puetz, J.; Raedel, L.; Reimann, R.; Rongen, M.; Schimp, M.; Schoenen, S.; Schumacher, L.; Stahlberg, M.; Vehring, M.; Wallraff, M.; Wiebusch, C.H. [RWTH Aachen University, III. Physikalisches Institut, Aachen (Germany); Bai, X. [South Dakota School of Mines and Technology, Physics Department, Rapid City, SD (United States); Barwick, S.W.; Yodh, G. [University of California, Department of Physics and Astronomy, Irvine, CA (United States); Bay, R.; Filimonov, K.; Price, P.B.; Woschnagg, K. [University of California, Department of Physics, Berkeley, CA (United States); Beatty, J.J. [Ohio State University, Department of Physics and Center for Cosmology and Astro-Particle Physics, Columbus, OH (United States); Ohio State University, Department of Astronomy, Columbus, OH (United States); Tjus, J.B.; Bos, F.; Eichmann, B.; Kroll, M.; Mandelartz, M.; Schoeneberg, S. [Ruhr-Universitaet Bochum, Fakultaet fuer Physik and Astronomie, Bochum (Germany); Becker, K.H.; Bindig, D.; Fischer-Wasels, T.; Helbing, K.; Hickford, S.; Hoffmann, R.; Klaes, J.; Kopper, S.; Naumann, U.; Obertacke Pollmann, A.; Omairat, A.; Posselt, J.; Soldin, D. [University of Wuppertal, Department of Physics, Wuppertal (Germany); Benabderrahmane, M.L. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Berley, D.; Blaufuss, E.; Cheung, E.; Felde, J.; Hellauer, R.; Hoffman, K.D.; Huelsnitz, W.; Maunu, R.; Olivas, A.; Schmidt, T.; Song, M.; Sullivan, G.W.; Wissing, H. [University of Maryland, Department of Physics, College Park, MD (United States); Besson, D.Z. [University of Kansas, Department of Physics and Astronomy, Lawrence, KS (United States); Binder, G.; Gerhardt, L.; Ha, C.; Klein, S.R.; Miarecki, S.; Tatar, J. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Boersma, D.J.; Botner, O.; Euler, S.; Hallgren, A.; Perez de los Heros, C.; Stroem, R.; Taavola, H.; Unger, E. [Uppsala University, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); and others

    2016-03-15

    Various extensions of the Standard Model motivate the existence of stable magnetic monopoles that could have been created during an early high-energy epoch of the Universe. These primordial magnetic monopoles would be gradually accelerated by cosmic magnetic fields and could reach high velocities that make them visible in Cherenkov detectors such as IceCube. Equivalently to electrically charged particles, magnetic monopoles produce direct and indirect Cherenkov light while traversing through matter at relativistic velocities. This paper describes searches for relativistic (v ≥ 0.76 c) and mildly relativistic (v ≥ 0.51 c) monopoles, each using one year of data taken in 2008/2009 and 2011/2012, respectively. No monopole candidate was detected. For a velocity above 0.51 c the monopole flux is constrained down to a level of 1.55 x 10{sup -18} cm{sup -2} s{sup -1} sr{sup -1}. This is an improvement of almost two orders of magnitude over previous limits. (orig.)

  4. Searches for relativistic magnetic monopoles in IceCube

    International Nuclear Information System (INIS)

    Aartsen, M.G.; Hill, G.C.; Robertson, S.; Wallace, A.; Whelan, B.J.; Abraham, K.; Bernhard, A.; Coenders, S.; Gross, A.; Holzapfel, K.; Huber, M.; Jurkovic, M.; Krings, K.; Resconi, E.; Turcati, A.; Veenkamp, J.; Ackermann, M.; Berghaus, P.; Bernardini, E.; Bretz, H.P.; Cruz Silva, A.H.; Gluesenkamp, T.; Gora, D.; Jacobi, E.; Karg, T.; Middell, E.; Mohrmann, L.; Nahnhauer, R.; Schoenwald, A.; Spiering, C.; Stasik, A.; Stoessl, A.; Strotjohann, N.L.; Terliuk, A.; Usner, M.; Santen, J. van; Yanez, J.P.; Adams, J.; Aguilar, J.A.; Ansseau, I.; Heereman, D.; Meagher, K.; Meures, T.; O'Murchadha, A.; Pinat, E.; Raab, C.; Ahlers, M.; Arguelles, C.; Beiser, E.; Braun, J.; Chirkin, D.; Day, M.; Desiati, P.; Diaz-Velez, J.C.; Fahey, S.; Feintzeig, J.; Ghorbani, K.; Gladstone, L.; Griffith, Z.; Halzen, F.; Hanson, K.; Hoshina, K.; Jero, K.; Karle, A.; Kelley, J.L.; Kheirandish, A.; McNally, F.; Merino, G.; Morse, R.; Richter, S.; Sabbatini, L.; Tobin, M.N.; Tosi, D.; Vandenbroucke, J.; Wandkowsky, N.; Wendt, C.; Westerhoff, S.; Wille, L.; Xu, D.L.; Ahrens, M.; Bohm, C.; Dumm, J.P.; Finley, C.; Flis, S.; Hulth, P.O.; Hultqvist, K.; Walck, C.; Wolf, M.; Zoll, M.; Altmann, D.; Classen, L.; Kappes, A.; Tselengidou, M.; Anderson, T.; Arlen, T.C.; Dunkman, M.; Huang, F.; Keivani, A.; Lanfranchi, J.L.; Pankova, D.V.; Quinnan, M.; Tesic, G.; Archinger, M.; Baum, V.; Boeser, S.; Del Pino Rosendo, E.; Di Lorenzo, V.; Eberhardt, B.; Ehrhardt, T.; Foesig, C.C.; Koepke, L.; Kroll, G.; Krueckl, G.; Sander, H.G.; Sandroos, J.; Schatto, K.; Steuer, A.; Wiebe, K.; Auffenberg, J.; Bissok, M.; Blumenthal, J.; Gier, D.; Glagla, M.; Haack, C.; Hansmann, B.; Kemp, J.; Konietz, R.; Leuermann, M.; Leuner, J.; Paul, L.; Puetz, J.; Raedel, L.; Reimann, R.; Rongen, M.; Schimp, M.; Schoenen, S.; Schumacher, L.; Stahlberg, M.; Vehring, M.; Wallraff, M.; Wiebusch, C.H.; Bai, X.; Barwick, S.W.; Yodh, G.; Bay, R.; Filimonov, K.; Price, P.B.; Woschnagg, K.; Beatty, J.J.; Tjus, J.B.; Bos, F.; Eichmann, B.; Kroll, M.; Mandelartz, M.; Schoeneberg, S.; Becker, K.H.; Bindig, D.; Fischer-Wasels, T.; Helbing, K.; Hickford, S.; Hoffmann, R.; Klaes, J.; Kopper, S.; Naumann, U.; Obertacke Pollmann, A.; Omairat, A.; Posselt, J.; Soldin, D.; Benabderrahmane, M.L.; Berley, D.; Blaufuss, E.; Cheung, E.; Felde, J.; Hellauer, R.; Hoffman, K.D.; Huelsnitz, W.; Maunu, R.; Olivas, A.; Schmidt, T.; Song, M.; Sullivan, G.W.; Wissing, H.; Besson, D.Z.; Binder, G.; Gerhardt, L.; Ha, C.; Klein, S.R.; Miarecki, S.; Tatar, J.; Boersma, D.J.; Botner, O.; Euler, S.; Hallgren, A.; Perez de los Heros, C.; Stroem, R.; Taavola, H.; Unger, E.

    2016-01-01

    Various extensions of the Standard Model motivate the existence of stable magnetic monopoles that could have been created during an early high-energy epoch of the Universe. These primordial magnetic monopoles would be gradually accelerated by cosmic magnetic fields and could reach high velocities that make them visible in Cherenkov detectors such as IceCube. Equivalently to electrically charged particles, magnetic monopoles produce direct and indirect Cherenkov light while traversing through matter at relativistic velocities. This paper describes searches for relativistic (v ≥ 0.76 c) and mildly relativistic (v ≥ 0.51 c) monopoles, each using one year of data taken in 2008/2009 and 2011/2012, respectively. No monopole candidate was detected. For a velocity above 0.51 c the monopole flux is constrained down to a level of 1.55 x 10 -18 cm -2 s -1 sr -1 . This is an improvement of almost two orders of magnitude over previous limits. (orig.)

  5. Resonances

    DEFF Research Database (Denmark)

    an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to realize...

  6. Testing GUTs: where do monopoles fit

    International Nuclear Information System (INIS)

    Ellis, J.

    1982-10-01

    The report shows why the inadequacies of the standard model of elementary particles impel some theorists toward embedding the strong, weak and electromagnetic interactions in a simple GUT group, and explains why the grand unification scale and hence the GUM (Grand Unified Monopoles) mass are expected to be so large (greater than or equal to 10 14 GeV). It goes on to describe some model GUTs, notably minimal SU(5) and supersymmetric (susy) GUTs. The grand unified analogues of generalized Cabibbo mixing angles are introduced relevant to the prediction of baryon decay modes in different theories as well as to the Decay modes catalyzed by GUMs. Phenomenologies of conventional and susy GUTs are contrasted including the potential increase in the grand unification scale as well as possible different baryon decay modes in susy GUTs. The phenomenology of GUMs is discussed, principally their ability to catalyze baryon decays. Some of the astrophysical and cosmological constraints on GUMs, GUMs, which make it difficult to imagine ever seeing a GUM and may impose serious restrictions on GUT model-building via their behavior in the very early universe are introduced. Finally, the reasons why GUMs are crucial aspects and tests of GUTs are summarized

  7. Miniaturised self-resonant split-ring resonator antenna

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Breinbjerg, Olav

    2009-01-01

    at the resonance is governed by the arc length of the monopole. Numerical and experimental results are presented for an antenna configuration of 1/23.4 wavelength in diameter (ka~0.134). The antenna is tuned to 50 ohms without any matching network, and its efficiency is measured to be 17.5%....

  8. Slow magnetic monopoles search in NOvA

    Science.gov (United States)

    Antoshkin, Alexander; Frank, Martin

    2018-04-01

    The NOvA far detector is well suited for finding exotic particles due to its technical features (see [1]). One type of those exotic particles is a "slow" magnetic monopole. It is assumed that the energy deposition of such monopoles should be enough to be registered (see [2]). Measurement of the expected signals was performed on the NOvA test bench at JINR (see [3]). Result of this measurement allows us to perform slow monopole's research using NOvA software and hardware with high efficiency. As a whole, the research can lead to a discovery, or it can limit the existence of monopoles in a wide range of parameters, previously unreachable in other experiments (MACRO, SLIM, RICE, IceCube). Several special software tools have been developed. Slow Monopole Trigger has been created and implemented in the NOvA Data-Driven-Trigger system. Also, an online reconstruction algorithm has been developed and tested on 5% of the data. A technical description of these tools and current results of the analysis are presented in this work.

  9. RCNP E398 {sup 16}O,{sup 12}C(p,p’) experiment: Measurement of the γ-ray emission probability from giant resonances in relation to {sup 16}O,{sup 12}C(ν,ν’) reactions

    Energy Technology Data Exchange (ETDEWEB)

    Ou, I.; Yamada, Y.; Mori, T.; Yano, T.; Sakuda, M. [Department of Physics, Okayama University, Okayama 700-8530 (Japan); Tamii, A.; Suzuki, T.; Yosoi, M.; Aoi, N.; Ideguchi, E.; Hashimoto, T.; Miki, K.; Ito, T.; Iwamoto, C.; Yamamoto, T. [Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki, Osaka 567-0047 (Japan); Akimune, H. [Department of Physics, Konan University, Okamoto 8-9-1, Higashinada, Kobe 658-8501 (Japan)

    2015-05-15

    We propose to measure the γ-ray emission probability from excited states above 5 MeV including giant resonance of {sup 16}O and {sup 12}C as a function of excitation energy in 1-MeV step. Here, we measure both the excitation energy (E{sub x}=5-30MeV) at the forward scattering angles (0°-3°) of the {sup 16}O, {sup 12}C (p, p’) reaction using Grand-Raiden Spectrometer and the energy of γ-rays (E{sub γ}) using an array of NaI(Tl) counters. The purpose of the experiment is to provide the basic and important information not only for the γ-ray production from primary neutral-current neutrino-oxygen (-carbon) interactions but also for that from the secondary hadronic (neutron-oxygen and -carbon) interactions.

  10. Z2 monopoles in the standard SU(2) lattice gauge theory model

    International Nuclear Information System (INIS)

    Mack, G.; Petkova, V.B.

    1979-04-01

    The standard SU(2) lattice gauge theory model without fermions may be considered as a Z 2 model with monopoles and fluctuating coupling constants. At low temperatures β -1 (= small bare coupling constant) the monopoles are confined. (orig.) [de

  11. Circumvention of Parker's bound on galactic magnetic monopoles

    International Nuclear Information System (INIS)

    Dicus, D.A.; Teplitz, V.L.; Maryland Univ., College Park

    1983-01-01

    There is a possibility that a magnetic monopole has been observed. The monopole density implied by the observation appears to violate bounds on the density of such particles derived from the total mass density of the Universe and from the existence of galactic magnetic fields. It is shown that the observation is not inconsistent with these bounds if the monopoles and antimonopoles are bound into positronium like states with principal quantum n high enough so that the Earth's magnetic field will break them apart, but small enough so that the weaker galactic magnetic field will not. A range of values for n are determined and show that lifetimes for such bound states are longer than the current age of the Universe. (author)

  12. Detecting Magnetic Monopoles in Spin Ice with NV-magnetometry

    Science.gov (United States)

    Flicker, Felix; Kirschner, Franziska; Yao, Norman; Blundell, Stephen

    2017-04-01

    Magnetic monopoles, isolated north and south poles, appear not to exist as fundamental particles in our universe. Nevertheless, it has been proposed that they may emerge as quasiparticles in certain materials: the geometrically-frustrated `spin ice' pyrochlores dysprosium and holmium titanate. Despite a great deal of experimental and theoretical work, the smoking gun signature of magnetic monopoles in spin ice remains to be discovered. A promising candidate for the detection of individual magnetic monopoles comes in the form of Nitrogen-Vacancy (NV) defects in diamond, which act as very sensitive probes of vector magnetic fields on the nanometre scale. We present the result of Monte Carlo modeling for the precise signals one would expect to see with nanometre-scale probes such as NV-magnetometers or muon spin rotation.

  13. Monopole Effect on Isotopes in Sn and Pb Regions

    Directory of Open Access Journals (Sweden)

    M. KHITER

    2016-11-01

    Full Text Available Abstract. When going toward in description of neutron-rich nuclei, the monopole field plays a determining role in the properties of the quasiparticle states and their interactions. Detailed theoretical in shell model calculations of the characteristics of the neutron-rich isotopes in 132Sn and 208Pb regions are performed using the monopole hamiltonien effect. Some modification mentioned in literatures of effectives interactions are introduced for evaluated the effective single-particle energies. Their effect show a successful and consistent description of excitation energies spectra of these nuclei.Keywords:Nuclear Structure, Monopole Hamiltonian, Odd-Odd Nuclei,Three body Effects, Similarity, 21.60.Cs; 27.60. +j; 21.30.Fe

  14. Spinor monopole harmonics and the Pauli spin equation

    International Nuclear Information System (INIS)

    Pereira, J.G.; Ferreira, P.L.

    1982-01-01

    In the framework of Wu and Yang theory of U(1) magnetic monopoles, two problems are revisited: (i) the binding of spin-0 monopole to a spin-1/2 particle possessing an arbitrary magnetic dipole moment, and (ii) the energy levels and properties of the electron-dyon system. In both problems, the spin-1/2 particle is assumed to obey the Pauli spin equation. Spin-orbit and other higher order terms are treated as a perturbation, in connection with the second mentioned problem. Wu and Yang's spinor monopole harmonics allow an elegant and simplified treatment of those problems. The results obtained are in good agreement with those obtained in older papers. (Author) [pt

  15. Large, real time detectors for solar neutrinos and magnetic monopoles

    International Nuclear Information System (INIS)

    Gonzalez-Mestres, L.

    1990-01-01

    We discuss the present status of superheated superconducting granules (SSG) development for the real time detection of magnetic monopoles of any speed and of low energy solar neutrinos down to the pp region (indium project). Basic properties of SSG and progress made in the recent years are briefly reviewed. Possible ways for further improvement are discussed. The performances reached in ultrasonic grain production at ∼ 100 μm size, as well as in conventional read-out electronics, look particularly promising for a large scale monopole experiment. Alternative approaches are briefly dealt with: induction loops for magnetic monopoles; scintillators, semiconductors or superconducting tunnel junctions for a solar neutrino detector based on an indium target

  16. Low-SAR metamaterial-inspired printed monopole antenna

    Science.gov (United States)

    Hossain, M. I.; Faruque, M. R. I.; Islam, M. T.; Ali, M. T.

    2017-01-01

    In this paper, a low-SAR metamaterial-embedded planar monopole antenna is introduced for a wireless communication system. A printed monopole antenna is designed for modern mobile, which operates in GSM, UMTS, LTE, WLAN, and Bluetooth frequency bands. A metamaterial structure is designed to use in the mobile handset with a multi-band printed monopole antenna. The finite integration technique of the CST microwave studio is used in this study. The measurement of antenna performances is taken in an anechoic chamber, and the SAR values are measured using COMOSAR system. The results indicate that metamaterial structure leads to reduce SAR without affecting antenna performance significantly. According to the measured results, the metamaterial attachment leads to reduce 87.7% peak SAR, 68.2% 1-g SAR, and 46.78% 10-g SAR compared to antenna without metamaterial.

  17. On the fate of superheavy magnetic monopoles in a neutron star

    International Nuclear Information System (INIS)

    Kuzmin, V.A.; Rubakov, V.A.; AN SSSR, Moscow. Inst. Yadernykh Issledovanij)

    1983-02-01

    We propose two possible scenarios of the behaviour of superheavy magnetic monopoles in a neutron star, in which the monopole-antimonopole annihilation rate is sufficiently large to prevent the enormous heating of a neutron star due to the monopole induced neutron decays. We find that the galactic monopole flux of order 10 -16 cm -2 s -1 ster -1 can be compatible with the observational limit on the X-ray luminosity of neutron stars. (author)

  18. Bohr quantum theory of the magnetic monopoles and classical electron electromagnetic mass problem

    OpenAIRE

    Pankovic, Vladan

    2010-01-01

    In the first part of this work we apply Bohr (old or naive quantum atomic) theory for analysis of the remarkable electro-dynamical problem of magnetic monopoles. We reproduce formally exactly some basic elements of the Dirac magnetic monopoles theory, especially Dirac electric/magnetic charge quantization condition. It follows after application of Bohr theory at the system, simply called magnetic monopole "atom", consisting of the practically standing, massive magnetic monopole as the "nucleu...

  19. Possibility of experimental detection of the Dirac-Schwinger heavy mass monopoles

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, I F [AN SSSR, Novosibirsk. Inst. Matematiki; Panfil, S L [AN SSSR, Novosibirsk. Inst. Avtomatiki i Ehlektrometrii

    1982-12-01

    A possibility of the Dirac-Schwinger point heavy-mass monopoles detection in scattering or production of photons at large angles via the monopole loop, is discussed. The monopoles with masses M < or approximately from 50 to 100 GeV may be found in experiments at PETRA and PEP, and monopoles with masses M < or approximately from 2 to 3 TeV may be discovered in future experiments in colliding photon beams of 50-300 GeV energies.

  20. Algebraic reduction of the 't Hooft-Polyakov monopole to the Dirac monopole

    International Nuclear Information System (INIS)

    Landi, G.; Marmo, G.

    1988-01-01

    In the context of the algebraic description of gauge fields by means of extensions of Lie algebras considered in previous articles by the authors, we define the notion of reduction of an extension of Lie algebras. Given a connection we define the holonomy algebra and the holonomy sequence of the connection and we prove that it is always possible to reduce the extension we start with to the holonomy sequence of the connection. As an example we construct a 't Hooft-Polyakov-like extension of algebras and reduce it to the extension which describes the Dirac monopole as discussed in a previous paper by the authors. The supersymmetric version of all results is obtained by replacing ordinary Lie algebras with Lie superalgebras. (orig.)

  1. Gravitational magnetic monopoles and Majumdar-Papapetrou stars

    International Nuclear Information System (INIS)

    Lemos, Jose P.S.; Zanchin, Vilson T.

    2006-01-01

    During the 1990s a large amount of work was dedicated to studying general relativity coupled to non-Abelian Yang-Mills type theories. Several remarkable results were accomplished. In particular, it was shown that the magnetic monopole, a solution of the Yang-Mills-Higgs equations can indeed be coupled to gravitation. For a low Higgs mass it was found that there are regular monopole solutions, and that for a sufficiently massive monopole the system develops an extremal magnetic Reissner-Nordstroem quasihorizon with all the matter fields laying inside the horizon. These latter solutions, called quasi-black holes, although nonsingular, are arbitrarily close to having a horizon, and for an external observer it becomes increasingly difficult to distinguish these from a true black hole as a critical solution is approached. However, at precisely the critical value the quasi-black hole turns into a degenerate space-time. On the other hand, for a high Higgs mass, a sufficiently massive monopole develops also a quasi-black hole, but at a critical value it turns into an extremal true horizon, now with matter fields showing up outside. One can also put a small Schwarzschild black hole inside the magnetic monopole, the configuration being an example of a non-Abelian black hole. Surprisingly, Majumdar-Papapetrou systems, Abelian systems constructed from extremal dust (pressureless matter with equal charge and energy densities), also show a resembling behavior. Previously, we have reported that one can find Majumdar-Papapetrou solutions which are everywhere nonsingular, but can be arbitrarily close of being a black hole, displaying the same quasi-black-hole behavior found in the gravitational magnetic monopole solutions. With the aim of better understanding the similarities between gravitational magnetic monopoles and Majumdar-Papapetrou systems, here we study a particular system, namely a system composed of two extremal electrically charged spherical shells (or stars

  2. Universal monopole scaling near transitions from the Coulomb phase.

    Science.gov (United States)

    Powell, Stephen

    2012-08-10

    Certain frustrated systems, including spin ice and dimer models, exhibit a Coulomb phase at low temperatures, with power-law correlations and fractionalized monopole excitations. Transitions out of this phase, at which the effective gauge theory becomes confining, provide examples of unconventional criticality. This Letter studies the behavior at nonzero monopole density near such transitions, using scaling theory to arrive at universal expressions for the crossover phenomena. For a particular transition in spin ice, quantitative predictions are made by mapping to the XY model and confirmed using Monte Carlo simulations.

  3. Performance and application of a fourfold monopole mass spectrometer

    International Nuclear Information System (INIS)

    Richards, J.A.; Huey, R.M.

    1978-01-01

    Some preliminary tests with an experimental fourfold monopole mass spectrometer described, illustrating that the device performs acceptably (at the low resolutions used) despite the fact that the field-forming surfaces of the driven electrodes are only one quadrant of a cylinder. Coupling between adjacent channels is shown not to be a problem so that applications requiring simultaneous measurements using two or more of the monopole channels can be entertained. Owing to its parellel structure the instrument is suggested as being suited particularly to isotope ratio measurements with precisions which could be significantly better than would be possible with a quadrupole device. (Auth.)

  4. Hamiltonian reduction and supersymmetric mechanics with Dirac monopole

    International Nuclear Information System (INIS)

    Bellucci, Stefano; Nersessian, Armen; Yeranyan, Armen

    2006-01-01

    We apply the technique of Hamiltonian reduction for the construction of three-dimensional N=4 supersymmetric mechanics specified by the presence of a Dirac monopole. For this purpose we take the conventional N=4 supersymmetric mechanics on the four-dimensional conformally-flat spaces and perform its Hamiltonian reduction to three-dimensional system. We formulate the final system in the canonical coordinates, and present, in these terms, the explicit expressions of the Hamiltonian and supercharges. We show that, besides a magnetic monopole field, the resulting system is specified by the presence of a spin-orbit coupling term. A comparision with previous work is also carried out

  5. Topology without cooling: instantons and monopoles near to deconfinement

    International Nuclear Information System (INIS)

    Feurstein, M.; Markum, H.; Thurner, S.

    1998-01-01

    In an attempt to describe the change of topological structure of pure SU(2) gauge theory near deconfinement a renormalization group inspired method is tested. Instead of cooling, blocking and subsequent inverse blocking is applied to Monte Carlo configurations to capture topological features at a well-defined scale. We check that this procedure largely conserves long range physics like string tension. UV fluctuations and lattice artefacts are removed which otherwise spoil topological charge density and Abelian monopole currents. We report the behaviour of topological susceptibility and monopole current densities across the deconfinement transition and relate the two faces of topology to each other. First results of a cluster analysis are described. (orig.)

  6. Monopoles and rational maps: A note on a theorem of Donaldson

    International Nuclear Information System (INIS)

    Hurtubise, J.

    1985-01-01

    In a recent paper, Donaldson gave a description of the moduli space of SU(2) monopoles in terms of rational maps; this was done indirectly, via the associated solution of Nahm's equations. We give here an interpretation of these rational maps in terms of the monopole's spectral curve, and then as ''scattering data'' for the monopole itself. (orig.)

  7. Giant arachnoid granulation in a patient with benign intracranial hypertension

    International Nuclear Information System (INIS)

    Kiroglu, Yilmaz; Yaqci, Baki; Cirak, Bayram; Karabulut, Nevzat

    2008-01-01

    We report magnetic resonance (MR), computed tomography (CT) and angiographic imaging of an unusual giant arachnoid granulation in the superior sagittal sinus in a man with headache and vertigo. Intrasinus pressure measurements revealed a significant pressure gradient across the lesion. MR imaging is useful to identify giant arachnoid granulation and dural sinus thrombosis, whereas dural sinus pressure measurement in certain cases of giant arachnoid granulations can be used to evaluate the lesion as the cause of the patient's symptoms. (orig.)

  8. Giant arachnoid granulation in a patient with benign intracranial hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Kiroglu, Yilmaz; Yaqci, Baki; Cirak, Bayram; Karabulut, Nevzat [Pamukkale University, Department of Radiology, School of Medicine, Denizli (Turkey)

    2008-10-15

    We report magnetic resonance (MR), computed tomography (CT) and angiographic imaging of an unusual giant arachnoid granulation in the superior sagittal sinus in a man with headache and vertigo. Intrasinus pressure measurements revealed a significant pressure gradient across the lesion. MR imaging is useful to identify giant arachnoid granulation and dural sinus thrombosis, whereas dural sinus pressure measurement in certain cases of giant arachnoid granulations can be used to evaluate the lesion as the cause of the patient's symptoms. (orig.)

  9. Supersymmetry violation in elementary particle-monopole scattering

    International Nuclear Information System (INIS)

    Casher, A.; Shamir, Y.

    1991-10-01

    We show that the scattering of elementary particles on solitons (monopoles, fluxons, etc.) in supersymmetric gauge theories violates the relations dictated by supersymmetry at tree level. The violation arises because of the discrepancy between the spectra of bosonic and fermionic fluctuations and because of the fermionic nature of the supersymmetry generators. (author). 14 refs

  10. Comments on GUT monopole energy loss and ionization

    International Nuclear Information System (INIS)

    Hagstrom, R.

    1982-01-01

    A few comments about the likely behavior of the electromagnetic energy loss and ionization rates of super-slowly moving magnetic monopoles are presented. The questions of energy loss rates and ionization rates for super-low monopoles passing through matter are considered, concentrating on aspects of these issues which affect practical detection techniques. It is worthwhile here to emphasize that there is a potentially great distinction between energy loss rates and ionization rates and that the magnitude of this distinction is really the great issue which must be settled in order to understand the significance of experimental results from present and proposed investigations of the slow monopole question. Energy loss here means the total dE/dX of the projectile due to interactions with the electrons of the slowing medium. To the extent that nuclear collisions can be neglected, this so-called electronic energy loss is the relevant quantity in questions about whether monopoles stop within the earth's crust, whether they are slowed by interstellar plasmas, or the signal in a truly calorimetric measurement (measuring temperature rises along the trajectory), etc. Most of our successful detection techniques depend upon the promotion of ground state electrons into states which lie above some energy gap in the material of the detector: electrons must be knocked completely free from the gas atoms in a proportional chamber gas, electrons must be promoted to a higher band in solid scintillator plastics. These processes are generically identified as ionization

  11. Comments on the charge-monopole canonical formalism

    International Nuclear Information System (INIS)

    Comay, C.

    1988-01-01

    A recently published canonical formalism of a charge-monopole system written by means of Clifford algebras is discussed. It is shown that the introduction of the Lorentz force must be accompanied by the removal of the pseudo-scalar terms from the lagrangian. Several conclusions follow. (orig.)

  12. Half-monopoles in the Yang–Mills theory

    Indian Academy of Sciences (India)

    . A non-zero winding number in two or three dimensions must be associated with a point of double or triple degeneracy respectively, as we will see in our examples. Consider, for example, the 't Hooft–Polyakov monopole [5,6]. In this case,.

  13. Higher dimensional global monopole in Brans–Dicke theory

    Indian Academy of Sciences (India)

    Keywords. Global monopole; Brans–Dicke theory; higher dimension. PACS Nos 04.20.Jb; 98.80.Bp; 04.50.+h. 1. Introduction. The idea of higher dimensional theory was originated in super string and super gravity the- ories to unify gravity with other fundamental forces in nature. Solutions of Einstein field equations in higher ...

  14. Search for magnetic monopoles at the Chacaltaya cosmic ray laboratory

    International Nuclear Information System (INIS)

    Cecchini, S.; Giacomelli, G.; Giorgini, M.; Mandrioli, G.; Manzoor, S.; Margiotta, A.; Patrizii, L.; Popa, V.; Serra, P.; Spurio, M.; Togo, V.; Zanini, A.; Saavedra, O.; Zanini, A.; McDonald, J.; Pinfold, J.; Manzoor, S.; Rana, M. A.; Qureshi, I. E.; Shahzad, M. I.; Popa, V.; Ticona, R.; Velarde, A.; Cechini, S.

    2001-01-01

    The new large area (400 m 2 ) experiment - SLIM - to search for magnetic monopoles and other exotic massive particles is presented. It uses of nuclear track detectors and is being deployed at the Chacaltaya cosmic ray laboratory for at least 4 years. The detection capability of the experiment is discussed

  15. A new derivation of Dirac's magnetic monopole strength

    International Nuclear Information System (INIS)

    Panat, P V

    2003-01-01

    A new derivation of the strength of Dirac's magnetic monopole is presented which does not require an explicit form of the magnetic induction in terms of g, the magnetic pole strength. The derivation essentially uses a modification of Faraday's law of induction and quantization of angular momentum

  16. On the quantum field theory of charges and monopoles

    International Nuclear Information System (INIS)

    Calucci, G.; Jengo, R.; Vallon, M.T.

    1981-11-01

    A treatment of the interaction between charges and monopoles is presented, in terms of functional integration over closed paths. The Lorentz covariance is preserved in all the steps of the procedure and the symmetry between electric charges and magnetic poles in the interaction is clearly displayed. Some instances of application are discussed. (author)

  17. Monopoles and instantons on partially compactified D-branes

    International Nuclear Information System (INIS)

    Lee, K.; Yi, P.

    1997-01-01

    Motivated by the recent D-brane constructions of world-volume monopoles and instantons, we study the supersymmetric SU(N) Yang-Mills theory on S 1 xR 3+1 , spontaneously broken by a Wilson loop. In addition to the usual N-1 fundamental monopoles, the Nth Bogomol close-quote nyi-Prasad-Sommerfield monopole appears from the Kaluza-Klein sector. When all N monopoles are present, net magnetic charge vanishes and the solution can be reinterpreted as a Wilson-loop instanton of unit Pontryagin number. The instanton-multimonopole moduli space is explicitly constructed, and seen to be identical to a Coulomb phase moduli space of a U(1) N gauge theory in 2+1 dimensions related to Kronheimer close-quote s gauge theory of SU(N)-type. This extends the results by Intriligator and Seiberg to the finite couplings that, in the infrared limit of Kronheimer close-quote s theory, the Coulomb phase parametrizes a centered SU(N) instanton. We also elaborate on the case of restored SU(N) symmetry. copyright 1997 The American Physical Society

  18. Magnetic monopole interactions: shell structure of meson and baryon states

    International Nuclear Information System (INIS)

    Akers, D.

    1986-01-01

    It is suggested that a low-mass magnetic monopole of Dirac charge g = (137/2)e may be interacting with a c-quark's magnetic dipole moment to produce Zeeman splitting of meson states. The mass M 0 = 2397 MeV of the monopole is in contrast to the 10 16 -GeV monopoles of grand unification theories (GUT). It is shown that shell structure of energy E/sub n/ = M 0 + 1/4nM 0 ... exists for meson states. The presence of symmetric meson states leads to the identification of the shell structure. The possible existence of the 2397-MeV magnetic monopole is shown to quantize quark masses in agreement with calculations of quantum chromodynamics (QCD). From the shell structure of meson states, the existence of two new mesons is predicted: eta(1814 +/- 50 MeV) with I/sup G/(J/sup PC/) = 0 + (0 -+ ) and eta/sub c/ (3907 +/- 100 MeV) with J/sup PC/ = 0 -+ . The presence of shell structure for baryon states is shown

  19. Capacitance and effective area of flush monopole probes.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Johnson, William Arthur; Morris, Marvin E.; Basilio, Lorena I.; Lehr, Jane Marie; Higgins, Matthew B.

    2004-08-01

    Approximate formulas are constructed and numerical simulations are carried out for electric field derivative probes that have the form of flush mounted monopoles. Effects such as rounded edges are included. A method is introduced to make results from two-dimensional conformal mapping analyses accurately apply to the three-dimensional axisymmetric probe geometry

  20. Three-Dimensional Gauge Theories and ADE Monopoles

    OpenAIRE

    Tong, David

    1998-01-01

    We study three-dimensional N=4 gauge theories with product gauge groups constructed from ADE Dynkin diagrams. One-loop corrections to the metric on the Coulomb branch are shown to coincide with the metric on the moduli space of well-seperated ADE monopoles. We propose that this correspondence is exact.

  1. Search for Magnetic Monopoles in Polar Volcanic Rocks

    DEFF Research Database (Denmark)

    Bendtz, K.; Milstead, D.; Hächler, H. -P.

    2013-01-01

    following the passage of igneous rock samples through a SQUID-based magnetometer. A total of 24.6 kg of rocks from various selected sites, among which 23.4 kg are mantle-derived rocks from the Arctic and Antarctic areas, was analyzed. No monopoles were found, and a 90% confidence level upper limit of 9.8 x...

  2. Thermodynamic fluctuations and the monopole density of the early Universe

    International Nuclear Information System (INIS)

    Diosi, L.; Lukacs, B.

    1984-10-01

    The probability of thermodynamic fluctuations is calculated by explicitly using the Riemannian structure of the thermodynamic state space. By means of this probability distribution, a correlation volume can be defined. Identifying this volume with one domain in the GUT continuum at the symmetry breaking phase transition in the early Universe, a prediction can be obtained for the primordial monopole density. (author)

  3. Search for magnetic monopoles with the neutrino telescope ANTARES

    International Nuclear Information System (INIS)

    Picot-Clemente, N.

    2010-01-01

    The ANTARES neutrino telescope is located at a 2500 meters depth, and is composed of an array of 900 photomultipliers installed for the detection of Cherenkov light emitted by neutrino-induced muons, after having interacted with matter, and in order to reconstruct their directions. However, besides of being capable of detecting high energy neutrinos, neutrino telescopes could measure the incoming flux of magnetic monopoles in the detector. In this work, were first presented the different methods used in order to calibrate the photomultipliers, which are the heart of a neutrino telescope. The possibility of detecting magnetic monopoles with ANTARES was then discussed, and a first analysis optimised for the search for high velocity magnetic monopoles showed the great sensitivity offered by the telescope. Finally, a track reconstruction algorithm was modified, and a new analysis this time sensitive over a wider range of velocities was performed. After the application of the last analysis on the data taken in 2008 with the ANTARES telescope, new upper limits on the upward going magnetic monopole flux, of masses lower than 10 14 GeV were obtained, and are the best experimental constraints on their flux for the velocity region β ∼ [0.65, 0.995]. (author)

  4. Does the SU(5) monopole catalyze proton decay

    International Nuclear Information System (INIS)

    Hussain, F.; Pak, N.K.

    1983-08-01

    The role of Higgs induced mass for the fermions in the SU(5) monopole catalysis of the baryon decay problem is investigated. We find that the inclusion of such a mass does not rule out the Rubakov effect but it does suppress the catalysis cross-section

  5. Behavioral and Biological Effects of Resonant Electromagnetic Absorption in Rats.

    Science.gov (United States)

    1976-11-01

    for 23-550 MHz, biological phantom materials to simulate tissue properties, monopole -above-ground radiation chamber, design of a waveguide slot array...Resonant Electromagnetic Power Absorption in Rats" L T OF FTCTIF S A,’L i .LIS SFigure Pa 1 A photograiph of the monopole -above-gruund radiation...and mice without ground effects (L/2b = 3.25 where 21Tb is the "average" circumference of the animals) ........ .................... ... 20 8

  6. Time Dependent Density Functional Theory description of giant resonances in transition metal complexes: The photoionization dynamics of Cr(CO)6

    International Nuclear Information System (INIS)

    Stener, M.; Fronzoni, G.; Decleva, P.

    2009-01-01

    The photoionization dynamics of Cr(CO) 6 has been calculated at the TDDFT level, employing a basis set of multicentric B-spline functions with the explicit treatment of the photoelectron continuum. The cross section and the asymmetry parameter profiles of all the valence orbitals have been considered and compared with the available experimental data. The most interesting spectral feature is the intense autoionization resonance Cr 3p → Cr 3d observed in the experiment of band A, which is very well reproduced by present calculation at the TDDFT level. Other observed spectral features have been ascribed to shape resonances and assigned according to the dipole-prepared continuum orbital nature. The present TDDFT scheme proves accurate and practicable on large and complex systems containing transition metal compounds, for the description and the interpretation of the photoionization dynamics.

  7. Transforming giants.

    Science.gov (United States)

    Kanter, Rosabeth Moss

    2008-01-01

    Large corporations have long been seen as lumbering, inflexible, bureaucratic--and clueless about global developments. But recently some multinationals seem to be transforming themselves: They're engaging employees, moving quickly, and introducing innovations that show true connection with the world. Harvard Business School's Kanter ventured with a research team inside a dozen global giants--including IBM, Procter & Gamble, Omron, CEMEX, Cisco, and Banco Real--to discover what has been driving the change. After conducting more than 350 interviews on five continents, she and her colleagues came away with a strong sense that we are witnessing the dawn of a new model of corporate power: The coordination of actions and decisions on the front lines now appears to stem from widely shared values and a sturdy platform of common processes and technology, not from top-down decrees. In particular, the values that engage the passions of far-flung workforces stress openness, inclusion, and making the world a better place. Through this shift in what might be called their guidance systems, the companies have become as creative and nimble as much smaller ones, even while taking on social and environmental challenges of a scale that only large enterprises could attempt. IBM, for instance, has created a nonprofit partnership, World Community Grid, through which any organization or individual can donate unused computing power to research projects and see what is being done with the donation in real time. IBM has gained an inspiring showcase for its new technology, helped business partners connect with the company in a positive way, and offered individuals all over the globe the chance to contribute to something big.

  8. YOUNG SOLAR SYSTEM's FIFTH GIANT PLANET?

    International Nuclear Information System (INIS)

    Nesvorný, David

    2011-01-01

    Studies of solar system formation suggest that the solar system's giant planets formed and migrated in the protoplanetary disk to reach the resonant orbits with all planets inside ∼15 AU from the Sun. After the gas disk's dispersal, Uranus and Neptune were likely scattered by the gas giants, and approached their current orbits while dispersing the transplanetary disk of planetesimals, whose remains survived to this time in the region known as the Kuiper Belt. Here we performed N-body integrations of the scattering phase between giant planets in an attempt to determine which initial states are plausible. We found that the dynamical simulations starting with a resonant system of four giant planets have a low success rate in matching the present orbits of giant planets and various other constraints (e.g., survival of the terrestrial planets). The dynamical evolution is typically too violent, if Jupiter and Saturn start in the 3:2 resonance, and leads to final systems with fewer than four planets. Several initial states stand out in that they show a relatively large likelihood of success in matching the constraints. Some of the statistically best results were obtained when assuming that the solar system initially had five giant planets and one ice giant, with the mass comparable to that of Uranus and Neptune, and which was ejected to interstellar space by Jupiter. This possibility appears to be conceivable in view of the recent discovery of a large number of free-floating planets in interstellar space, which indicates that planet ejection should be common.

  9. Young Solar System's Fifth Giant Planet?

    Science.gov (United States)

    Nesvorný, David

    2011-12-01

    Studies of solar system formation suggest that the solar system's giant planets formed and migrated in the protoplanetary disk to reach the resonant orbits with all planets inside ~15 AU from the Sun. After the gas disk's dispersal, Uranus and Neptune were likely scattered by the gas giants, and approached their current orbits while dispersing the transplanetary disk of planetesimals, whose remains survived to this time in the region known as the Kuiper Belt. Here we performed N-body integrations of the scattering phase between giant planets in an attempt to determine which initial states are plausible. We found that the dynamical simulations starting with a resonant system of four giant planets have a low success rate in matching the present orbits of giant planets and various other constraints (e.g., survival of the terrestrial planets). The dynamical evolution is typically too violent, if Jupiter and Saturn start in the 3:2 resonance, and leads to final systems with fewer than four planets. Several initial states stand out in that they show a relatively large likelihood of success in matching the constraints. Some of the statistically best results were obtained when assuming that the solar system initially had five giant planets and one ice giant, with the mass comparable to that of Uranus and Neptune, and which was ejected to interstellar space by Jupiter. This possibility appears to be conceivable in view of the recent discovery of a large number of free-floating planets in interstellar space, which indicates that planet ejection should be common.

  10. Dielectric Analysis for Torque of a Solute Ion Coulomb Force Monopole Motor

    Science.gov (United States)

    Fresco, Anthony N.

    ASME Technical Paper ES2010-90396 "Solute Ion Coulomb Force Monopole Motor and Solute Ion Linear Alignment Propulsion" by the author describes a motor that is based on an arrangement of solute ion electric field monopoles.[1] That is, through a process called capacitive deionization, sodium and chlorine ions in salt water are captured and confined by an electrically conductive material to form electric field monopoles. At least four of the like charged monopoles (all negative or all positive) can be arranged on a disc. At least one stationary monopole of the same charge is placed adjacent to the disc and positioned so that a repulsive electric field is formed between the stationary monopole and at least one of the monopoles positioned on the disc so that the disc is then forced to rotate a shaft at the center of the disc. This paper analyzes the behavior of the dielectric materials forming part of the monopoles to show that the net torque on the motor is greater than zero and also illustrates a novel effect of polarization of a dielectric material positioned between two like-charged monopoles as occurs in the configuration of the monopole motor and a deficiency in the conventional closed path analysis for work performed during movement of electric charges that emit electrostatic fields by failing to consider the effects of dielectric materials in shielding the electrostatic fields. The monopole motor connected to an to electrical generator can provide continuous on-board electrical power to electrical loads for local and deep space applications including power to electrode assemblies designed for linear alignment of like-charged solute ions as a means of propulsion and particle acceleration as described in the ES2010-90396 paper. Details of the monopole motor and the propulsion are available in WO 2008/024927 A2 (and US2010/0199632 A1) "Solute Ion Coulomb Force Acceleration and Electric Field Monopole Passive Voltage Source" by the author Ref.[2].

  11. Giant Cell Arteritis

    Science.gov (United States)

    Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. ... arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia ...

  12. Binary black hole in a double magnetic monopole field

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Maria J. [Utah State University, Department of Physics, Logan, UT (United States); Max Planck Institute for Gravitational Physics, Potsdam (Germany)

    2018-01-15

    Ambient magnetic fields are thought to play a critical role in black hole jet formation. Furthermore, dual electromagnetic signals could be produced during the inspiral and merger of binary black hole systems. In this paper, we derive the exact solution for the electromagnetic field occurring when a static, axisymmetric binary black hole system is placed in the field of two magnetic or electric monopoles. As a by-product of this derivation, we also find the exact solution of the binary black hole configuration in a magnetic or electric dipole field. The presence of conical singularities in the static black hole binaries represent the gravitational attraction between the black holes that also drag the external two monopole field. We show that these off-balance configurations generate no energy outflows. (orig.)

  13. Cosmological monopoles and non-Abelian black holes

    International Nuclear Information System (INIS)

    Brihaye, Yves; Hartmann, Betti; Radu, Eugen; Stelea, Cristian

    2007-01-01

    We discuss magnetic monopole solutions of the Einstein-Yang-Mills-Higgs equations with a positive cosmological constant. These configurations approach asymptotically the de Sitter spacetime background and exist only for a nonzero Higgs potential. We find that the total mass of the solutions within the cosmological horizon is finite. However, their mass evaluated by using the surface counterterm method outside the cosmological horizon at early/late time infinity generically diverges. Magnetic monopole solutions with finite mass and non-integer charge exist however in a truncation of the theory with a vanishing Higgs field. Both solutions with a regular origin and cosmological black holes are studied, special attention being paid to the computation of the global charges

  14. Binary black hole in a double magnetic monopole field

    Science.gov (United States)

    Rodriguez, Maria J.

    2018-01-01

    Ambient magnetic fields are thought to play a critical role in black hole jet formation. Furthermore, dual electromagnetic signals could be produced during the inspiral and merger of binary black hole systems. In this paper, we derive the exact solution for the electromagnetic field occurring when a static, axisymmetric binary black hole system is placed in the field of two magnetic or electric monopoles. As a by-product of this derivation, we also find the exact solution of the binary black hole configuration in a magnetic or electric dipole field. The presence of conical singularities in the static black hole binaries represent the gravitational attraction between the black holes that also drag the external two monopole field. We show that these off-balance configurations generate no energy outflows.

  15. A Statistical Model of Current Loops and Magnetic Monopoles

    International Nuclear Information System (INIS)

    Ayyer, Arvind

    2015-01-01

    We formulate a natural model of loops and isolated vertices for arbitrary planar graphs, which we call the monopole-dimer model. We show that the partition function of this model can be expressed as a determinant. We then extend the method of Kasteleyn and Temperley-Fisher to calculate the partition function exactly in the case of rectangular grids. This partition function turns out to be a square of a polynomial with positive integer coefficients when the grid lengths are even. Finally, we analyse this formula in the infinite volume limit and show that the local monopole density, free energy and entropy can be expressed in terms of well-known elliptic functions. Our technique is a novel determinantal formula for the partition function of a model of isolated vertices and loops for arbitrary graphs

  16. Gsm 1900Umts Printed Monopole Antenna For Mobile Base Station

    Directory of Open Access Journals (Sweden)

    Nyi Nyi Lwin

    2015-08-01

    Full Text Available In this paper printed rectangular monopole antenna which is basically printed microstrip patch antenna with partial ground plane is designed for mobile base station. The substrate FR4 with a relative permittivity of 4.4 and thickness 1.8 is used in design. In addition the printed monopole antenna is of low profile in appearance and suitable for most application. The proposed antenna can cover GSM1900 1850-1990 MHz and UMTS 1920-2170 MHz bands. Design and simulation processes are carried out with the aid of FEKO software which is used for the analysis of electromagnetic problems. Simulation results of the return loss gain and radiation patterns are presented.

  17. Fractal Based Triple Band High Gain Monopole Antenna

    Science.gov (United States)

    Pandey, Shashi Kant; Pandey, Ganga Prasad; Sarun, P. M.

    2017-10-01

    A novel triple-band microstrip fed planar monopole antenna is proposed and investigated. A fractal antenna is created by iterating a narrow pulse (NP) generator model at upper side of modified ground plane, which has a rhombic patch, for enhancing the bandwidth and gain. Three iterations are carried out to study the effects of fractal geometry on the antenna performance. The proposed antenna can operate over three frequency ranges viz, 3.34-4.8 GHz, 5.5-10.6 GHz and 13-14.96 GHz suitable for WLAN 5.2/5.8 GHz, WiMAX 3.5/5.5 GHz and X band applications respectively. Simulated and measured results are in good agreements with each others. Results show that antenna provides wide/ultra wide bandwidths, monopole like radiation patterns and very high antenna gains over the operating frequency bands.

  18. Possible circumvention of Parker's bound on galactic magnetic monopoles

    International Nuclear Information System (INIS)

    Dicus, D.A.; Teplitz, V.L.

    1983-04-01

    There is a possibility that a magnetic monople has observed. The monopole density implied by the observation appears to violate bounds on the density of such particles derived from the total mass density of the universe and from the existence of galactic magnetic fields. We show that the observation is not inconsistent with these bounds if the monopoles and antimonopoles are bound into positronium - like states with principal quantum n high enough so that the earth's magnetic field will break them apart, but small enough so that the weaker galactic mangetic field will not. We determine a range of values for n and show that lifetimes for such bound states are longer than the current age of the universe

  19. Study of the neutron decays of giant resonances excited by the inelastic scattering of 36 Ar on 90 Zr and 94 Zr targets at 44 MeV/u: a signature of multiphonon states

    International Nuclear Information System (INIS)

    Pascalon-Rozier, V.

    1997-01-01

    In inelastic heavy ion scattering, to angles near to the grazing angle, giant resonances (GR) are excited with very large differential cross sections. It has been shown that multiphonon states, states built with several GR quanta, can also been excited. These states can be revealed through the measurement of their decay by light particle emission. In this thesis, we report on the study of inelastic scattering of 36 Ar at 44 MeV/u on target of 90 Zr and 94 Zr, measured in coincidence with neutrons detected with the EDEN multidetector. The analysis of the inelastic spectra show evidence for a structure at high excitation energy, exhibiting characteristics compatible with a two-photon excitation. The construction of missing energy spectra allows us to the study of the GR and the high energy structure. In both nuclei, the GR presents a direct decay branch of 8%, which yields informations on the microscopic structure of the resonance. A two phonon state, interpreted as two weakly coupled GR's, built on one top of the other, and each phonon is expected to exhibit the same direct decay pattern as the GR. Such a simple decay is observed in the data, proving that the structure observed is due to the excitation of the two phonon state in both nuclei studied. Finally, we present a theoretical development based on Random Phase Approximation calculation, predicting that the two phonon state should be very harmonic. This result is in agreement with experimental studies of double phonon states over a large range of nuclei (from A = 12 to 208) carried out with several different probes. (author)

  20. Electron scattering studies of selected electric and magnetic dipole and quadrupole transitions in light and heavy nuclei, the new multipole giant resonances and atomic transitions - recent results from the DALINAC

    International Nuclear Information System (INIS)

    Richter, A.

    1977-01-01

    Recent experimental work from the Darmstadt electron linear accelerator (DALINAC) is briefly summarized. Particular emphasis is given to the following topics: high resolution inelastic electron scattering (ΔE approximately 30 keV FWHM) has been used to study the radiative width and magnetization density of the 2 + , T = 1 state at 16.11 MeV in 12 C, E2 strength distribution in 28 Si below an excitation energy of 13 MeV and the isospin forbidden E1 electroexcitation of the 1 - , T = 0 state at 6.95 MeV in 40 Ca. High resolution inelastic electron scattering was also employed to determine certain M1 transitions in 14 N, 28 Si, 39 K, 58 Ni, 90 Zr and 208 Pb and the M2 strength distribution in the two heaviest nuclei. At medium energy resolution (ΔE approximately 200 keV FWHM) spectra at various angles and bombarding energies have been measured from (4-31) MeV for 208 Pb. They are being analyzed in order to determine E0, E1, E2, E3 and M1 giant resonance strength in the continuum. The Z and E dependence and the scaling behaviour of the atomic inner shell ionization cross section at relativistic electron impact is studied on gaseous and solid targets. (orig./BJ) [de