International Nuclear Information System (INIS)
Mathews, G.J.; Bloom, S.D.; Hausman, R.F. Jr.
1983-01-01
Shell-model calculations of the Gamow-Teller strength function for 90 Zr have been performed utilizing a realistic finite-range two-body interaction in a model space consisting of the 2p and 1g shells. The effects of admixtures of two-particle two-hole excitations in 90 Nb, mostly due to the spin and isospin exchange components of the nucleon-nucleon force, are discussed. Ground state correlations in 90 Zr are also added via seniority-zero two-proton excitations from the 2p shell into the 1g/sub 9/2/ shell. With the correlations the Gamow-Teller strength function is in good agreement with the experimental results and accounts for essentially all of the observed dispersion of strength. The inclusion of these correlations does not, however, produce either a displacement of Gamow-Teller strength to higher excitation energies, or a significant change in the total strength. Thus, they cannot account for the observed Gamow-Teller quenching. The quenching factor derived by a comparison of our calculated results with experiment is 0.52
Effect on Tensor Correlations on Gamow- Teller States in 90Zr and 208Pb
International Nuclear Information System (INIS)
Bai, C. L.; Sagawa, H.; Zhang, H. Q.
2009-01-01
The tensor terms of the Skyrme effective interaction are included in the self-consistent Hartree-Fock plus Random Phase Approximation (HF-RPA) model. The Gamow-Teller (GT) strength function of 9 0Z r and 2 08P b are calculated with and without the tensor terms. The main peaks are moved downwards by about 2 MeV when including the tensor contribution. About 10% of the non-energy weighted sum rule is shifted to the excitation energy region above 30 MeV by the RPA tensor correlations. The contribution of the tensor terms to the energy weighted sum rule is given analytically, and compared to the outcome of RPA. A microscopic origin of the quenching of GT sum rule is discussed in relation with the coupling to giant spin-quadrupole excitations by the tensor interactions.(author)
Effect of Tensor Correlations on Gamow-Teller States in 90Zr and 208Pb
International Nuclear Information System (INIS)
Bai, C. L.; Zhang, H. Q.; Zhang, X. Z.
2009-01-01
The tensor terms of the Skyrme effective interaction are included in the self-consistent Hartree-Fock plus Random Phase Approximation (HF-RPA) model. The Gamow-Teller (GT) strength functions of 9 0Z r and 2 08P b is calculated with and without the tensor terms. The main peaks are moved downwards by about 2 MeV when including the tensor contribution. About 10% of the non-energy weighted sum rule is shifted to the excitation energy region above 30 MeV by the RPA tensor correlations. The contribution of the tensor terms to the energy weighted sum rule is given analytically, and compared to the outcome of RPA. A microscopic origin of the quenching of GT sum rule due to the tensor force is discussed.(author)
Gamow-Teller Strength Distributions for Some Magic Nuclei
Directory of Open Access Journals (Sweden)
Necla ÇAKMAK
2014-12-01
Full Text Available The total Gamow-Teller strengths and their energy distributions for 96Zr, 96Sr, 54Ca, 28O, 24C and 14C have been obtained within the framework of Random Phase Approximation (RPA. The effective interaction potential has been described by considering the commutativity of the Gamow-Teller operator with the central part of the nuclear Hamiltonian.
Gamow-teller transitions: progress and problems
International Nuclear Information System (INIS)
Walter, G.
1994-01-01
The determination of the Gamow-Teller (GT) matrix elements from beta-decay and charge exchange reactions has led to a series of discoveries concerning the structure of the nucleus and the properties of spin-isospin transitions in nuclei. The study of GT distribution and strength, either by charge exchange or weak decay, provides excellent tests for nuclear models as these parameters are extremely sensitive to the details of nuclear structure. Recent improvements of these models have reduced, for the most part, differences between experiment and theory, allowing in turn a more reliable estimate of weak decay rates in stellar matter. A better understanding of the 'missing strength' and of the failure of many experiments to detect the strength that is present have also been obtained. Recently, it appears also that weak decay studies in selected region (proton or neutron rich) of the N-Z plane give access to the GT giant resonance. (J.S.). 65 refs., 10 figs
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.)
Gamow-Teller beta decay of proton-rich nuclei
International Nuclear Information System (INIS)
Klepper, O.; Rykaczewski, K.
1990-11-01
The beta decays of 48 Mn and of even-even nuclei near the double shell-closures at 100 Sn and 146 Gd are currently investigated at the GSI on-line mass separator. Their Gamow-Teller strength are surveyed in their present experimental status, together with related results from the ISOLDE (CERN) and ISOCELE (Orsay) separators, and are compared with predictions from different nuclear models. The strength of the 0 + → 1 + Gamow-Teller transitions is compiled in tables and graphs. (orig.)
Gamow teller strength from n-nucleus scattering
International Nuclear Information System (INIS)
Haeusser, O.
1989-08-01
Detailed studies of the spin-isospin structure of nuclear excitations are possible at TRIUMF's medium resolution spectrometer using the (n,p), ( p → , p →/ and (p,n) reactions. We discuss here results on isospin symmetry of inelastic nucleon scattering reactions populating isospin triads in A=6 and A=12 nuclei. The empirical ratio of L=0 isovector spin flip cross sections at 200-450 MeV and B(GT) for strong Gamow-Teller transitions in p-shell nuclei is found to be larger than calculated in the DWIA using a free NN t-matrix. Based on empirical values of σ/B(GT) the β + Gamow Teller strength function from (n,p) reactions on (sd) and (fp) shell targets is substantially quenched compared to current nuclear structure models using the free-nucleon axial-vector coupling constant. (Author) 33 refs., 6 figs
Chiral filter, axial charges and Gamow-Teller strengths
International Nuclear Information System (INIS)
Rho, M.
1983-09-01
The different ways that nuclear matter responds to the weak axial-vector current are interpreted in terms of modification of the ''vacuum'' in baryon-rich environments. The notion of ''chiral filter'' is introduced. Use of a ward identity is suggested. The Gamow-Teller quenching and the enhanced axial charge in O + O - transitions follow from this. I also discuss briefly possible relevance of the nucleon as a topological soliton configuration to the global property of nuclear axial response functions
Gamow Teller strength from charge exchange reactions at intermediate energies
International Nuclear Information System (INIS)
Haeusser, O.
1989-07-01
Detailed studies of the spin-isospin structure of nuclear excitations are possible at TRIUMF's medium resolution spectrometer using the (n,p), ( p → , p →/ ) and (p,n) reactions. We discuss here results on isospin symmetry of inelastic nucleon scattering reactions populating isospin triads in A=6 and A=12 nuclei. The β + Gamow Teller strength function from (n,p) reactions on (sd) and (fp) shell targets is found to be substantially quenched compared to current nuclear structure models using the free-nucleon axial-vector coupling constant. (Author) 22 refs., 3 figs
Gamow-Teller matrix elements from 00 ( p,n) cross section
International Nuclear Information System (INIS)
Goodman, C.D.; Goulding, C.A.; Greenfield, M.B.; Rapaport, J.; Bainum, D.E.; Foster, C.C.; Love, W.G.; Petrovich, F.
1980-01-01
After simple corrections for distortion effects, 120-MeV, 0 0 (p,n) cross sections are found to be proportional to the squares of the corresponding Fermi and Gamow-Teller matrix elements extracted from β-decay measurements. It is suggested that this proportionality can be used to extract Gamow-Teller matrix elements for transitions inaccessible to β decay
Role of the momentum transfer in the quenching of the Gamow-Teller strength
Energy Technology Data Exchange (ETDEWEB)
Marketin, Tomislav [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany); Physics Department, Faculty of Science, University of Zagreb (Croatia); Martinez-Pinedo, Gabriel [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany); Paar, Nils; Vretenar, Dario [Physics Department, Faculty of Science, University of Zagreb (Croatia)
2012-07-01
A fully consistent calculation of the Gamow-Teller strength is presented, based on a microscopic theoretical framework. Nuclear ground state is determined using the relativistic Hartree-Bogolyubov (RHB) model with density dependent meson-nucleon coupling constants, and transition rates are calculated via proton-neutron relativistic quasiparticle RPA using the same interaction as in the RHB equations. The (p,n) probe has a similar spin-isospin operator structure to the Gamow-Teller (GT) operator. However, they become comparable only if the GT cross section is measured at a very small momentum transfer q. At higher momentum transfer the isovector spin monopole (IVSM) mode occurs, with the r{sup 2}{sigma}{tau} transition operator. Unlike the Gamow-Teller operator which excites only the 0{Dirac_h}{omega} transitions, the isovector spin monopole operator can also excite 2{Dirac_h}{omega} transitions and can change the strength distribution at high excitation energies. We explore the strength beyond the resonance, examine the effect of momentum transfer on the total strength and compare the results with recent measurements.
Lorentz-Lorenz quenching for the Gamow-Teller sum rule
International Nuclear Information System (INIS)
Delorme, J.; Ericson, M.; Figureau, A.
1984-03-01
We investigate the modification of the Gamow-Teller sum rule brought in by nucleonic excitations. The general trend of the data is well reproduced. The value of the force which mixes nucleonic and nuclear excitations is discussed
Isospin symmetry of T-z=+/- 3/2 ->+/- 1/2 Gamow-Teller transitions in A=41 nuclei
Fujita, Y; Shimbara, Y; Adachi, T; Berg, GPA; Fujita, H; Hatanaka, K; Kamiya, J; Nakanishi, K; Sakemi, Y; Sasaki, S; Shimizu, Y; Tameshige, Y; Uchida, M; Wakasa, T; Yosoi, M
2004-01-01
Under the assumption that isospin T is a good quantum number, isobaric analog states and various analogous transitions are expected in isobars with mass number A. The, strengths of T-z = +/-3/2 --> 1/2 analogous Gamow-Teller (GT) transitions and analogous M1 transitions within the A = 41 isobar
Isospin symmetry of T-z=+/- 3/2 ->+/- 1/2 Gamow-Teller transitions in A=41 nuclei
Fujita, Y; Shimbara, Y; Adachi, T; Berg, GPA; Fujita, H; Hatanaka, K; Kamiya, J; Nakanishi, K; Sakemi, Y; Sasaki, S; Shimizu, Y; Tameshige, Y; Uchida, M; Wakasa, T; Yosoi, M
Under the assumption that isospin T is a good quantum number, isobaric analog states and various analogous transitions are expected in isobars with mass number A. The, strengths of T-z = +/-3/2 --> 1/2 analogous Gamow-Teller (GT) transitions and analogous M1 transitions within the A = 41 isobar
Gamow-Teller strength distributions and electron capture rates for 55Co and 56Ni
International Nuclear Information System (INIS)
Nabi, Jameel-Un; Rahman, Muneeb-Ur
2005-01-01
The Gamow-Teller strength (GT) distributions and electron capture rates on 55 Co and 56 Ni have been calculated using the proton-neutron quasiparticle random phase approximation theory. We calculate these weak interaction mediated rates over a wide temperature (0.01x10 9 -30x10 9 K) and density (10-10 11 gcm -3 ) domain. Electron capture process is one of the essential ingredients involved in the complex dynamics of supernova explosion. Our calculations of electron capture rates show differences with the reported shell model diagonalization approach calculations and are comparatively enhanced at presupernova temperatures. We note that the GT strength is fragmented over many final states
A study of Gamow-Teller strength in A=37 nuclei
International Nuclear Information System (INIS)
Aufderheide, M.B.; Bloom, S.D.; Resler, D.A.; Goodman, C.D.
1992-01-01
An analysis is made of the recent β+ decay measurements of Garcia et al., in order to see whether the 1981 37 Cl(p,n) 37 Ar measurements of Rapaport et al. are consistent with them. Garcia et al., were not able to determine the amount of Gamow-Teller strength in the isobaric analog state (IAS) or the Coulomb mixing of Fermi strength to a state near the IAS, and were forced to determine the amount of Gamow-Teller strength in the daughter 1371 keV state by making the branching ratios sum to unity. These uncertainties leave a range of possible values open which we investigate. We find that the experiments are consistent within part of this range. We also examine the effect of this range of allowed values on solar and supernova neutrino cross sections of 37 Cl and find weak dependence on the uncertainties described here. We discuss how this range can be narrowed so that the consistency of the two experiments can be conclusively tested
Cheoun, Myung-Ki; Ha, Eunja
2013-07-01
With the advent of high analysis technology in detecting the Gamow-Teller (GT) excited states beyond one nucleon emission threshold, the quenching of the GT strength to the Ikeda sum rule (ISR) seems to be recovered by the high-lying (HL) GT states. We address that these HL GT excited states result from the smearing of the Fermi surface by the increase of the chemical potential owing to the deformation within a framework of the deformed quasi-particle random phase approximation (DQRPA). Detailed mechanism leading to the smearing is discussed, and comparisons to the available experimental data on 76Ge,82Se and N = 20 nuclei are shown to explain the strong peaks on the HL GT excited states.
International Nuclear Information System (INIS)
Cheoun, Myung-Ki; Ha, Eunja
2013-01-01
With the advent of high analysis technology in detecting the Gamow-Teller (GT) excited states beyond one nucleon emission threshold, the quenching of the GT strength to the Ikeda sum rule (ISR) seems to be recovered by the high-lying (HL) GT states. We address that these HL GT excited states result from the smearing of the Fermi surface by the increase of the chemical potential owing to the deformation within a framework of the deformed quasi-particle random phase approximation (DQRPA). Detailed mechanism leading to the smearing is discussed, and comparisons to the available experimental data on 76 Ge, 82 Se and N = 20 nuclei are shown to explain the strong peaks on the HL GT excited states
Characteristics of the Gamow-Teller Force in the β- Decay of 40Zr98
International Nuclear Information System (INIS)
Raden Oktova
2002-01-01
The characteristics of the β - decay force for the Gamow-Teller transition in the p-h and the p-p channels in the heavy neutron-rich nucleus 40 Zr 98 have been studied. The ground state single-particle levels in the parent nucleus were calculated self-consistently using the Fayans energy-density functional, and from them the quasi-particle basis was obtained using the BCS model. The residual charge-changing force responsible for the β - transition was taken as having a zero-range (a delta function); in the p-h channel the spin-isospin exchange → σ 1 . → σ 2 → τ 1 . → τ 2 term in the Migdal-Larkin force was used, and that in the p-p channel was a constant. The method employed was the proton-neutron QRPA (pnQRPA). The results show that the proton-neutron pairing p-p force in the Gamow-Teller decay is negligible for the nucleus considered. The value of the p-h force obtained is g ' = 0.735, slightly larger than the standard value of g ' = 0.7 commonly used for stable nuclei. (author)
Gamow-Teller decay of T = 1 nuclei to odd-odd N = Z nuclei
Energy Technology Data Exchange (ETDEWEB)
Lisetskiy, A F [National Superconducting Cyclotron Laboratory, MSU, East Lansing, MI 48824 (United States); Gelberg, A [Institute for Nuclear Physics, University of Cologne, 50937 Cologne (Germany); Institute of Physical and Chemical Reasearch (RIKEN), Wako, 351-0198 (Japan); Brentano, P von [Institute for Nuclear Physics, University of Cologne, 50937 Cologne (Germany)
2005-01-01
Transition strengths of Gamow-Teller decay of T{sub z} = {+-}1 nuclei to N = Z odd-odd nuclei have been calculated in a two-nucleon approximation for spherical and deformed nuclei. The results obtained for the latter are quite close to the values obtained by full-space shell-model calculations and to the experiment.
Quenching of the Gamow-Teller matrix element in closed LS-shell-plus-one nuclei
International Nuclear Information System (INIS)
Towner, I.S.
1989-06-01
It is evident that nuclear Gamow-Teller matrix elements determined from β-decay and charge-exchange reactions are significantly quenched compared to simple shell-model estimates based on one-body operators and free-nucleon coupling constants. Here we discuss the theoretical origins of this quenching giving examples from light nuclei near LS-closed shells, such as 16 0 and 40 Ca. (Author) 12 refs., 2 tabs
QRPA estimate for the Δ(1232) cotribution to the Gamow-Teller decay of heavy nuclei
International Nuclear Information System (INIS)
Suhonen, J.
1991-01-01
The contribution of the Δ(1232) isobars to the nuclear beta decay strength function is estimated in the framework of the charge-changing form of the QRPA. This procedure is applied to neutron-deficient tin isotopes. The results imply that the quenching of the low-energy Gamow-Teller decay strength cannot attributed to the presence of delta admixtures in the nuclear wave function. (orig.)
Gamow-Teller strength in the β-decay of 36Ca
International Nuclear Information System (INIS)
Trinder, W.; Adelberger, E.G.; Janas, Z.; Keller, H.; Krumbholz, K.; Pfuetzner, M.; Rykaczewski, K.
1994-11-01
The β-decay of 36 Ca has been studied at the projectile fragment separator at GSI Darmstadt. The Gamow-Teller strength function B(GT), deduced from the observed β-delayed proton- and γ-emission and from the measured half-life of 102(2) ms, is compared to results obtained from large-scale sd-shell model calculations. (orig.)
International Nuclear Information System (INIS)
Poirier, E.
2002-12-01
Nuclei with A ∼ 70 along the N=Z line are known to be the scene of phenomena closely related to the nuclear deformation and are of particular interest since theoretical mean field calculations predict that a large part of the Gamow-Teller resonance might be located below the ground state of the mother nucleus and then be accessible through β-decay studies. These results have shown the effect of the shape of the ground state on the intensity of the Gamow-Teller strength. Thus, the experimental determination, through δ-decay, of the Gamow-Teller strength distribution and the comparison to the theoretical predictions allow to pin down the quadrupolar deformation parameter of the ground state of the parent nucleus. In order to study the neutron deficient isotopes of krypton (A=72,73,74,75) and strontium (A=76,77,78) and to establish the β-strength on the full energy range, a new total absorption spectrometer (TAgS) has been built in the frame of an international collaboration and installed at the (SOLDE/CERN mass separator. For the data analysis, the response function R of the spectrometer has been calculated by means of Monte-Carlo simulations, based on the GEANT4 code, and of a statistical description of the level scheme in the daughter nucleus. The β-feeding distribution has been obtained from experimental spectra through a method based on Bayes theorem and then converted into Gamow-Teller strength. The results coming from the 74 Kr decay analysis allow to describe the ground state of such a nucleus as the coexistence of an oblate shape and of a prolate shape. In the case of 76 Sr, the experimental Gamow-Teller strength distribution strongly indicates a prolate deformation. (author)
Beta decay of 97Ag: evidence for the Gamow-Teller resonance near 100Sn
International Nuclear Information System (INIS)
Hu Zhiqiang
1999-03-01
In two complementary measurements, a cube like array of 6 Euroball-Cluster germanium detectors and a total-absorption γ-spectrometer were used to investigate the β decay of 97 Ag, a three proton-hole nucleus with respect to the 100 Sn core. The half-life and Q EC value of the decay of the 9/2 + ground-state of 97 Ag were determined to be 25.9(4) s and 6.98(11) MeV respectively. A total of 603 γ rays (578 new) was observed, and 151 levels (132 new) in 97 Pd have been identified. An interesting β-delayed γ cascade was observed, which comprises 6 γ-transitions with a de-excitation pattern involving an initial increase of the level spin. The Gamow-Teller (GT) β-decay strength distributions from the two measurements reveal a large GT resonance around 4 MeV with a width of about 1.8 MeV. The hindrance factor for the total GT strength summed from the ground-state up to 6 MeV excitation energy in 97 Pd, amounts to 4.3(6) with reference to a shell-model prediction. This factor is discussed in comparison with a core-polarization and a Monte-Carlo shell-model calculation. (orig.)
Double Gamow-Teller Transitions and its Relation to Neutrinoless β β Decay
Shimizu, Noritaka; Menéndez, Javier; Yako, Kentaro
2018-04-01
We study the double Gamow-Teller (DGT) strength distribution of 48Ca with state-of-the-art large-scale nuclear shell model calculations. Our analysis shows that the centroid energy of the DGT giant resonance depends mostly on the isovector pairing interaction, while the resonance width is more sensitive to isoscalar pairing. Pairing correlations are also key in neutrinoless β β (0 ν β β ) decay. We find a simple relation between the centroid energy of the 48Ca DGT giant resonance and the 0 ν β β decay nuclear matrix element. More generally, we observe a very good linear correlation between the DGT transition to the ground state of the final nucleus and the 0 ν β β decay matrix element. The correlation, which originates on the dominant short-range character of both transitions, extends to heavier systems including several β β emitters and also holds in energy-density functional results. Our findings suggest that DGT experiments can be a very valuable tool to obtain information on the value of 0 ν β β decay nuclear matrix elements.
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
The beta-decay of 48Mn: improved data on Gamow-Teller quenching
International Nuclear Information System (INIS)
Szerypo, J.; Bazin, D.; Brown, B.A.
1991-01-01
Beta-decay studies of very proton-rich nuclides allow to investigate the phenomenon of quenching of Gamow-Teller transitions. A presentation of the experimental techniques is followed by the discussion of preliminray results of the measurements in comparison to shell-model calculations. A corresponding reinvestigation is discussed. A mass-separated 48 Mn beam was used from 12 C( 40 Ca,p3n) reactions. The 48 Mn decay spectroscopy was performed simultaneously in two beam lines of the mass separator. (G.P.) 13 refs.; 2 figs
Energy Technology Data Exchange (ETDEWEB)
Poirier, E
2002-12-01
Nuclei with A {approx} 70 along the N=Z line are known to be the scene of phenomena closely related to the nuclear deformation and are of particular interest since theoretical mean field calculations predict that a large part of the Gamow-Teller resonance might be located below the ground state of the mother nucleus and then be accessible through {beta}-decay studies. These results have shown the effect of the shape of the ground state on the intensity of the Gamow-Teller strength. Thus, the experimental determination, through {delta}-decay, of the Gamow-Teller strength distribution and the comparison to the theoretical predictions allow to pin down the quadrupolar deformation parameter of the ground state of the parent nucleus. In order to study the neutron deficient isotopes of krypton (A=72,73,74,75) and strontium (A=76,77,78) and to establish the {beta}-strength on the full energy range, a new total absorption spectrometer (TAgS) has been built in the frame of an international collaboration and installed at the (SOLDE/CERN mass separator. For the data analysis, the response function R of the spectrometer has been calculated by means of Monte-Carlo simulations, based on the GEANT4 code, and of a statistical description of the level scheme in the daughter nucleus. The {beta}-feeding distribution has been obtained from experimental spectra through a method based on Bayes theorem and then converted into Gamow-Teller strength. The results coming from the {sup 74}Kr decay analysis allow to describe the ground state of such a nucleus as the coexistence of an oblate shape and of a prolate shape. In the case of {sup 76}Sr, the experimental Gamow-Teller strength distribution strongly indicates a prolate deformation. (author)
Ratio of Gamow-Teller to Fermi strength observed in /sup 13,14/C(p,n) at 492 and 590 MeV
International Nuclear Information System (INIS)
Ullmann, J.L.; Rapaport, J.; Lisowski, P.W.
1988-01-01
It has been recognized for a number of years that certain spin-isospin components of the nucleon-nucleus effective interaction can be inferred from (p,n) reactions to states of known nuclear structure. For L = 0, S = 0 and L = 0, S = 1 transitions, the 0-degree (p,n) cross section can be related respectively to Fermi and Gamow-Teller beta decay matrix elements. If these transitions occur in the same nucleus, the ratio of isovector spin-flip to non-spin-flip effective interactions can be measured without regard for absolute normalization. The best reaction to measure this is /sup 14/C(p,n) which goes by a pure Gamow-Teller transition to the 1/sup /plus// state at 3.95 MeV in /sup 14/N, and Fermi transition to the 2.31 MeV 0/sup /plus// state. This work extends the ratio measurements made at lower energies (ref. 1, 2, 3) to 492 and 590 MeV. We also report on the /sup 13/C(p,n) reaction which goes by a pure GT transition to the 3.51 MeV 3/2/sup /minus// state in /sup 13/N, but by a mixed Fermi plus Gamow-Teller transition to the 1/2/sup /minus// ground state. 11 refs., 4 figs., 2 tabs
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.)
Breaking of the SU(4) limit for the Gamow-Teller strength in N{proportional_to}Z nuclei
Energy Technology Data Exchange (ETDEWEB)
Petermann, I. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Gesellschaft fuer Schwerionenforschung Darmstadt, Darmstadt (Germany); Martinez-Pinedo, G. [Gesellschaft fuer Schwerionenforschung Darmstadt, Darmstadt (Germany); Langanke, K. [Gesellschaft fuer Schwerionenforschung Darmstadt, Darmstadt (Germany); Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Caurier, E. [Universite Louis Pasteur, Institut de Recherches Subatomiques, Strasbourg (France)
2007-12-15
We have performed large-scale shell model calculations of the Gamow-Teller strength distributions in N{proportional_to}Z pf-shell nuclei. These calculations were motivated by the experimental attempts to measure the low-lying GT strength for the even-even N=Z+2 or N=Z-2 nuclei {sup 46}Ti, {sup 50}Cr, {sup 54}Fe and {sup 62}Ge, where a sizable low-energy GT strength could be interpreted as reminiscence of SU(4) symmetry; in the limit of exact SU(4) symmetry the GT{sub -} strength would be concentrated in a single transition to the lowest T=0, J=1{sup +} state in the daughter. We confirm that the SU(4) symmetry is strongly broken by the spin-orbit interaction and by increasing neutron excess. (orig.)
Gamow-Teller strength functions from (→p,→p') scattering experiments
International Nuclear Information System (INIS)
Hausser, O.
1987-01-01
We present here recent (→p, →'p) results from TRIUMF that are relevant to the determination of spin-flip isovector strength functions in nuclei. Distortion factors needed for the extraction of nuclear-structure information have been deduced from cross sections and analyzing powers in elastic scattering for several energies and targets. Nonrelativistic optical potentials obtained by folding effective nucleon (N)-nucleus interactions with nuclear densities are found to overpredict both elastic and reaction cross sections, whereas Dirac calculations that include Pauli blocking are in good agreement with the data. Spin observables (S nn and A y ) for the quasi-elastic region in 54 Fe(→p, →p) at 290 MeV provide some evidence for the reduction of the effective proton mass predicted in relativistic mean-field theories as a consequence of the attractive scalar field in the nuclear medium. The energy dependence of the effective N-nucleus interaction at small momentum transfers has been investigated using isoscalar and isovector 1 + states in 28 Si as probe states. We find that the cross sections for the isovector transitions are in good agreement with predictions for the dominant Vστ part of the Franey-Love interaction. Gamow-Teller (GT) strength functions have been obtained in 24 Mg and 54 Fe from measurements of both cross sections and spin-flip probabilities S nn . The spin-flip cross sections σS nn are particularly useful in heavier nuclei to discriminate against a continuous background of ΔS = 0 excitations. In the (s, d) shell where full shell-model wave functions are available, the GT quenching factors (g A eff / g A free ) 2 ≅ 0.7 are in good agreement with those from recent (p, n) and (n, p) experiments. We show that a state-by-state comparison of (p, p') and (e, e') results has the potential of identifying pionic current contributions in (e, e'). The GT quenching factors in 54 Fe are smaller than in the (s, d) shell probably because of severely
Gamow-Teller resonances and a separable approximation for Skyrme tensor interactions
Directory of Open Access Journals (Sweden)
Severyukhin A. P.
2012-12-01
Full Text Available A finite rank separable approximation for the quasiparticle random phase approximation (QRPA with Skyrme interactions is applied to study properties of the Gamow-Teller (GT resonances in the neutron-rich Cd isotopes. This approximation enables one to reduce considerably the dimension of matrix that must be diagonalized to perform QRPA calculations in a very large configuration space. Our results from the SGII Skyrme interaction with the tensor interactions and the density-dependent zero-range pairing interaction show that the GT distribution is noticeably modified when the tensor correlations are taken into account. In particular, for 130Cd the dominant peak is moved 3.6 MeV downward and 10% of the GT distribution is shifted to the high excitation energy region near E=50MeV.
Gamow-Teller Strengths from (3He,t) Charge-Exchange Reaction
International Nuclear Information System (INIS)
Fujita, Yoshitaka
2006-01-01
Gamow-Teller (GT) transition is the most popular nuclear weak process with the nature of spin-isospin excitation. GT transitions in pf-shell nuclei, including those starting from unstable nuclei, are of interest, due to their importance in astrophysical processes. Weak processes, however, gives us rather limited information on the GT response of nuclei. We introduce high-resolution ( 3 He, t) reaction at 0 0 and at an intermediate beam energy as a new spectroscopic tool for studying GT excitations. Owing to the high energy-resolution of the reaction (∼ 30 keV), individual transitions can be observed up to the region of GT giant resonance. Assuming isospin symmetry for the T z = ±1 → 0 isobaric analogous transitions in isobars with mass number A, we present a new method to deduce GT transition strengths starting from proton rich exotic nuclei
Role of momentum transfer in the quenching of the Gamow-Teller strength
International Nuclear Information System (INIS)
Marketin, T.; Martínez-Pinedo, G.; Paar, N.; Vretenar, D.
2012-01-01
A recent analysis of (p,n) and (n,p) reaction data from 90 Zr was performed recently, where a significant amount of Gamow-Teller strength was found above the resonance, an energy region previously unreachable by experimental setups. The extracted strengths in the β − and the β + channel indicate that approximately 10% of the total strength necessary to satisfy the model independent Ikeda sum rule is missing. One possible source of this discrepancy is the treatment of the isovector spin monopole (IVSM) mode of excitation which has been found to occurr at high excitation energies. Employing the relativistic Hartree-Bogoliubov (RHB) model and the protonneutron relativistic quasiparticle random phase approximation (pn-RQRPA) to calculate the nuclear response, we explore the contribution of the IVSM mode to the total L= 0 strength and apply our results to the available data.
Role of momentum transfer in the quenching of the Gamow-Teller strength
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Marketin, T.; Martinez-Pinedo, G.; Paar, N.; Vretenar, D. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt, Germany and Physics Department, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Physics Department, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia)
2012-10-20
A recent analysis of (p,n) and (n,p) reaction data from {sup 90}Zr was performed recently, where a significant amount of Gamow-Teller strength was found above the resonance, an energy region previously unreachable by experimental setups. The extracted strengths in the {beta}{sub -} and the {beta}{sub +} channel indicate that approximately 10% of the total strength necessary to satisfy the model independent Ikeda sum rule is missing. One possible source of this discrepancy is the treatment of the isovector spin monopole (IVSM) mode of excitation which has been found to occurr at high excitation energies. Employing the relativistic Hartree-Bogoliubov (RHB) model and the protonneutron relativistic quasiparticle random phase approximation (pn-RQRPA) to calculate the nuclear response, we explore the contribution of the IVSM mode to the total L= 0 strength and apply our results to the available data.
q-Gamow states for intermediate energies
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Plastino, A. [La Plata National University and Argentina' s National Research Council, (IFLP-CCT-CONICET)-C. C. 727, 1900 La Plata (Argentina); Rocca, M.C., E-mail: mariocarlosrocca@gmail.com [La Plata National University and Argentina' s National Research Council, (IFLP-CCT-CONICET)-C. C. 727, 1900 La Plata (Argentina); Ferri, G.L. [Fac. de C. Exactas, National University La Pampa, Peru y Uruguay, Santa Rosa, La Pampa (Argentina); Zamora, D.J. [La Plata National University and Argentina' s National Research Council, (IFLP-CCT-CONICET)-C. C. 727, 1900 La Plata (Argentina)
2016-11-15
In a recent paper Plastino and Rocca (2016) [18] we have demonstrated the possible existence of Tsallis' q-Gamow states. Now, accelerators' experimental evidence for Tsallis' distributions has been ascertained only at very high energies. Here, instead, we develop a different set of q-Gamow states for which the associated q-Breit–Wigner distribution could easily be found at intermediate energies, for which accelerators are available at many locations. In this context, it should be strongly emphasized Vignat and Plastino (2009) [2] that, empirically, one never exactly and unambiguously “detects” pure Gaussians, but rather q-Gaussians. A prediction is made via Eq. (3.4).
International Nuclear Information System (INIS)
Neumann-Cosel, P. von; Byelikov, A.; Richter, A.; Shevchenko, A.; Adachi, T.; Fujita, Y.; Shimbara, Y.; Fujita, H.; Heger, A.; Kolbe, E.; Langanke, K.; Martinez-Pinedo, G.
2006-01-01
Some aspects of the importance of neutrino-induced reactions on nuclei within supernova physics are discussed. It is argued that important constraints on the experimentally unknown cross sections can be obtained from experimental studies of the nuclear response in selected cases. Examples are neutral-current induced reactions on fp-shell nuclei extracted from high-resolution inelastic electron scattering data providing the M1 strength distributions and the production of the exotic heavy, odd-odd nuclei 138La and 180Ta through charged-current reactions dominated by Gamow-Teller transitions. The Gamow-Teller strength can deduced from the (3He,t) charge-exchange reaction at zero degree
Gamow-Teller transitions and neutron-proton-pair transfer reactions
Van Isacker, P.; Macchiavelli, A. O.
2018-05-01
We propose a schematic model of nucleons moving in spin-orbit partner levels, j = l ± 1/2, to explain Gamow-Teller and two-nucleon transfer data in N = Z nuclei above 40Ca. Use of the LS coupling scheme provides a more transparent approach to interpret the structure and reaction data. We apply the model to the analysis of charge-exchange, 42Ca(3He,t)42Sc, and np-transfer, 40Ca(3He,p)42Sc, reactions data to define the elementary modes of excitation in terms of both isovector and isoscalar pairs, whose properties can be determined by adjusting the parameters of the model (spin-orbit splitting, isovector pairing strength and quadrupole matrix element) to the available data. The overall agreement with experiment suggests that the approach captures the main physics ingredients and provides the basis for a boson approximation that can be extended to heavier nuclei. Our analysis also reveals that the SU(4)-symmetry limit is not realized in 42Sc.
Nabi, Jameel-Un; Ishfaq, Mavra; Böyükata, Mahmut; Riaz, Muhammad
2017-10-01
At finite temperatures (≥ 107K), 76Se is abundant in the core of massive stars and electron capture on 76Se has a consequential role to play in the dynamics of core-collapse. The present work may be classified into two main categories. In the first phase we study the nuclear structure properties of 76Se using the interacting boson model-1 (IBM-1). The IBM-1 investigations include the energy levels, B (E 2) values and the prediction of the geometry. We performed the extended consistent-Q formalism (ECQF) calculation and later the triaxial formalism calculation (constructed by adding the cubic term to the ECQF). The geometry of 76Se can be envisioned within the formalism of the potential energy surface based on the classical limit of IBM-1 model. In the second phase, we reconfirm the unblocking of the Gamow-Teller (GT) strength in 76Se (a test case for nuclei having N > 40 and Z fashion. Results are compared with experimental data and previous calculations. The calculated GT distribution fulfills the Ikeda sum rule. Rates for β-delayed neutrons and emission probabilities are also calculated. Our study suggests that at high stellar temperatures and low densities, the β+-decay on 76Se should not be neglected and needs to be taken into consideration along with electron capture rates for simulation of presupernova evolution of massive stars.
Gamow-Teller strength in the continuum studied via the (p,n) reaction
International Nuclear Information System (INIS)
Wakasa, T.; Hatanaka, K.; Sakai, H.
2002-01-01
The double differential cross sections for θ lab between 0.0deg and 14.7deg and the polarization transfer coefficient D NN (0deg) for the 27 Al (p vector, n vector) reaction have been measured at a bombarding energy of 295 MeV. A multipole decomposition technique is applied for the cross section data to extract L=0, 1, 2, and 3 contributions. The Gamow-Teller (GT) strength B(GT) deduced from the L=0 contribution is compared with the B(GT) values calculated in a full sd shell-model space. The sum of B(GT) values up to 20 MeV excitation is S β- =4.0 ± 0.1 ± 0.1. A fairly large L=0 contribution is observed in the continuum region up to 50 MeV, which could be in part ascribed to the quenched GT strength. A limit on the effect that the Δ(1232)-isobar nucleon-hole admixture has upon the GT strength is estimated. (author)
Gamow-Teller transitions and proton-neutron pair correlation in N =Z odd-odd p -shell nuclei
Morita, Hiroyuki; Kanada-En'yo, Yoshiko
2017-10-01
We have studied the Gamow-Teller (GT) transitions from N =Z +2 neighbors to N =Z odd-odd nuclei in the p -shell region by using isospin-projected and β γ -constraint antisymmetrized molecular dynamics combined with the generator coordinate method. The calculated GT transition strengths from 0+1 states to 1+0 states such as 6He(01+1 ) →6Li(11+0 ) , 10Be(01+1 ) →10B(11+0 ) , and 14C(01+1 ) →14N(12+0 ) exhaust more than 50% of the sum rule. These N =Z +2 initial states and N =Z odd-odd final states are found to dominantly have S =0 ,T =1 n n pairs and S =1 ,T =0 p n pairs, respectively. Based on the two-nucleon (N N ) pair picture, we can understand the concentration of the GT strengths as the spin-isospin-flip transition n n (S =0 ,T =1 )→p n (S =1 ,T =0 ) in L S coupling. The GT transition can be a good probe to identify the spin-isospin partner states with n n pairs and p n pairs of N =Z +2 and N =Z odd-odd nuclei, respectively.
Beta decay of {sup 97}Ag: evidence for the Gamow-Teller resonance near {sup 100}Sn
Energy Technology Data Exchange (ETDEWEB)
Hu Zhiqiang
1999-03-01
In two complementary measurements, a cube like array of 6 Euroball-Cluster germanium detectors and a total-absorption {gamma}-spectrometer were used to investigate the {beta} decay of {sup 97}Ag, a three proton-hole nucleus with respect to the {sup 100}Sn core. The half-life and Q{sub EC} value of the decay of the 9/2{sup +} ground-state of {sup 97}Ag were determined to be 25.9(4) s and 6.98(11) MeV respectively. A total of 603 {gamma} rays (578 new) was observed, and 151 levels (132 new) in {sup 97}Pd have been identified. An interesting {beta}-delayed {gamma} cascade was observed, which comprises 6 {gamma}-transitions with a de-excitation pattern involving an initial increase of the level spin. The Gamow-Teller (GT) {beta}-decay strength distributions from the two measurements reveal a large GT resonance around 4 MeV with a width of about 1.8 MeV. The hindrance factor for the total GT strength summed from the ground-state up to 6 MeV excitation energy in {sup 97}Pd, amounts to 4.3(6) with reference to a shell-model prediction. This factor is discussed in comparison with a core-polarization and a Monte-Carlo shell-model calculation. (orig.)
Gamow-Teller strength and lepton captures rates on 66-71Ni in stellar matter
Nabi, Jameel-Un; Majid, Muhammad
Charge-changing transitions play a significant role in stellar weak-decay processes. The fate of the massive stars is decided by these weak-decay rates including lepton (positron and electron) captures rates, which play a consequential role in the dynamics of core collapse. As per previous simulation results, weak interaction rates on nickel (Ni) isotopes have significant influence on the stellar core vis-à-vis controlling the lepton content of stellar matter throughout the silicon shell burning phases of high mass stars up to the presupernova stages. In this paper, we perform a microscopic calculation of Gamow-Teller (GT) charge-changing transitions, in the β-decay and electron capture (EC) directions, for neutron-rich Ni isotopes (66-71Ni). We further compute the associated weak-decay rates for these selected Ni isotopes in stellar environment. The computations are accomplished by employing the deformed proton-neutron quasiparticle random phase approximation (pn-QRPA) model. A recent study showed that the deformed pn-QRPA theory is well suited for the estimation of GT transitions. The astral weak-decay rates are determined over densities in the range of 10-1011g/cm3 and temperatures in the range of 0.01 × 109-30 × 109K. The calculated lepton capture rates are compared with the previous calculation of Pruet and Fuller (PF). The overall comparison demonstrates that, at low stellar densities and high temperatures, our EC rates are bigger by as much as two orders of magnitude. Our results show that, at higher temperatures, the lepton capture rates are the dominant mode for the stellar weak rates and the corresponding lepton emission rates may be neglected.
High-resolution study of Gamow-Teller transitions in the 47Ti(3He,t)47V reaction
Ganioǧlu, E.; Fujita, H.; Fujita, Y.; Adachi, T.; Algora, A.; Csatlós, M.; Deaven, J. M.; Estevez-Aguado, E.; Guess, C. J.; Gulyás, J.; Hatanaka, K.; Hirota, K.; Honma, M.; Ishikawa, D.; Krasznahorkay, A.; Matsubara, H.; Meharchand, R.; Molina, F.; Okamura, H.; Ong, H. J.; Otsuka, T.; Perdikakis, G.; Rubio, B.; Scholl, C.; Shimbara, Y.; Susoy, G.; Suzuki, T.; Tamii, A.; Thies, J. H.; Zegers, R. G. T.; Zenihiro, J.
2013-01-01
Given the importance of Gamow-Teller (GT) transitions in nuclear structure and astrophysical nuclear processes, we have studied Tz=+3/2→+1/2, GT transitions starting from the 47Ti nucleus in the (3He,t) charge-exchange reaction at 0∘ and at an intermediate incident energy of 140 MeV/nucleon. The experiments were carried out at the Research Center for Nuclear Physics (RCNP), Osaka, using the high-resolution facility with a high-dispersion beam line and the Grand-Raiden spectrometer. With an energy resolution of 20 keV, individual GT transitions were observed and GT strength was derived for each state populated up to an excitation energy (Ex) of 12.5 MeV. The GT strength was widely distributed from low excitation energy up to 12.5 MeV, where we had to stop the analysis because of the high level density. The distribution of the GT strengths was compared with the results of shell model calculations using the GXPF1 interaction. The calculations could reproduce the experimental GT distributions well. The GT transitions from the ground state of 47Ti and the M1 transitions from the isobaric analog state in 47V to the same low-lying states in 47V are analogous. It was found that the ratios of GT transition strengths to the ground state, the 0.088-MeV state, and the 0.146-MeV state are similar to the ratios of the strengths of the analogous M1 transitions from the isobaric analog state (IAS) to these states. The measured distribution of the GT strengths was also compared with those starting from the Tz=+3/2 nucleus 41K to the Tz=+1/2 nucleus 41Ca.
Gamow-Teller strength in deformed nuclei within self-consistent pnQRPA with the Gogny force
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Martini M.
2014-03-01
Full Text Available In recent years fully consistent quasiparticle random-phase approximation (QRPA calculations using finite range Gogny force have been performed to study electromagnetic excitations of several axially-symmetric deformed nuclei up to the 238U. Here we present the extension of this approach to the charge-exchange nuclear excitations (pn-QRPA. In particular we focus on the Gamow-Teller (GT excitations. A comparison of the predicted GT strength distribution with existing experimental data is presented The role of nuclear deformation is shown. Special attention is paid to β-decay half-lives calculations for which experimental data exist.
International Nuclear Information System (INIS)
Batist, L.; Bykov, A.; Moroz, F.; Wittmann, V.; Alkhazov, G.D.; Keller, H.; Kirchner, R.; Klepper, O.; Roeckl, E.; Huyse, M.; Duppen, P. van; Reusen, G.; Plochocki, A.; Pfuetzner, M.; Rykaczewski, K.; Szerypo, J.; Zylicz, J.; Brown, B.A.
1994-10-01
The EC/β + -decay of the odd-odd nucleus 100 Ag was studied by means of total absorption γ-ray spectrometry. Most of the Gamow-Teller strength was found to be concentrated at an excitation energy of 5.6 MeV in 100 Pd, the FWHM of this resonance being 1.5 MeV. The measured strength distribution which is interpreted within the BCS approximation as being due to the dominant population of four-quasiparticle excitations, resembles the distribution predicted by an advanced shell-model calculation for the 98 Ag→ 98 Cd decay. (orig.)
Gamow-Teller strength functions from N-nucleus scattering experiments at 200-400 MeV
International Nuclear Information System (INIS)
Haeusser, O.; British Columbia Univ., Vancouver; Vetterli, M.C.
1988-01-01
Recent measurements of (n,p), (p vector, p vector') and (p,n) reactions at TRIUMF have made possible a detailed examination of the spin-isospin structure of nuclear excitations up to 50 MeV. Cross sections for 54 Fe(n,p) 54 Mn and spin-flip cross sections for 54 Fe (p vector, p vector') near 300 MeV have been used to estimate the nuclear response for different multipoles L, spin transfers (ΔS = 0,1), and isospins of the residual nucleus (T f = 1,2). Qualitative features of the spin-flip probabilities in (p vector, p vector') are in good agreement with recent surface-RPA calculations. Between 200 and 400 MeV the ΔL=0 spin-flip isovector component is well described by the central part V στ of the Franey-Love interaction. The Gamow-Teller strength S + in 54 Fe, which is of significance in models of pre-collapse supernovae, is found to be smaller by a factor of two than the best available shell model calculations. In (sd)-shell nuclei ( 24,26 Mg, 28 Si) about (70±15)% of the Gamow-Teller strength predicted by untruncated shell-model calculations is found at low excitation. (orig.)
International Nuclear Information System (INIS)
Brown, B.A.; Wildenthal, B.H.
1983-01-01
The magnetic dipole moments of states in mirror pairs of the sd-shell nuclei and the strengths of the Gamow-Teller beta decays which connect them are compared with predictions based on mixed-configuration shell-model wave functions. From this analysis we extract the average effective values of the single-particle matrix elements of the l, s, and [Y/sup( 2 )xs]/sup( 1 ) components of the M1 and Gamow-Teller operators acting on nucleons in the 0d/sub 5/2/, 1s/sub 1/2/, and 0d/sub 3/2/ orbits. These results are compared with the recent calculations by Towner and Khanna of the corrections to the free-nucleon values of these matrix elements which arise from the effects of isobar currents, mesonic-exchange currents, and mixing with configurations outside the sd shell
Observation of Fermi and Gamow-Teller strength in the 800 MeV(p,n) reaction
Energy Technology Data Exchange (ETDEWEB)
King, N S.P.; Lisowski, P W; Morgan, G L; Craig, P N; Jeppesen, R G; Lind, D A; Shepard, J R; Ullmann, J L; Zafiratos, C D; Goodman, C D
1986-08-07
Angular distributions have been measured for the (p,n) reaction on targets of /sup 6/Li, /sup 12/C, /sup 13/C, and /sup 15/N at 800 MeV with an energy resolution of 2.7 MeV allowing observation of discrete nuclear levels. As is the case at lower energies, this reaction is very selective, emphasizing Gamow-Teller (GT) and Fermi transitions. Absolute cross sections of pure GT transitions are reproduced by impulse approximation calculations. The ratio vertical strokeJsub(sigmatau)vertical stroke/sup 2//vertical strokeJsub(tau)vertical stroke/sup 2/ was extracted from /sup 13/C and /sup 15/N measurements at 800 MeV and from a /sup 13/C measurement at 318 MeV.
Ha, Eunja; Cheoun, Myung-Ki
2015-02-01
The deformed proton-neutron quasiparticle random phase approximation (QRPA) has been developed and applied to evaluate Gamow-Teller (GT) transition strength distributions, including high-lying excited states. The data of high-lying excited states are recently available beyond one or two nucleon threshold by charge exchange reactions using hundreds of MeV projectiles. Our calculations started with single-particle states calculated using a deformed, axially symmetric Woods-Saxon potential. The neutron-neutron and proton-proton pairing correlations are explicitly taken into account at the deformed Bardeen-Cooper-Schriffer theory. Additionally, the ground state correlations and two-particle and two-hole mixing states were included in the deformed QRPA. In this work, we used a realistic two-body interaction, given by the Brueckner G-matrix based on the CD Bonn potential to reduce the ambiguity on the nucleon-nucleon interactions inside nuclei. We applied our formalism to the GT transition strengths for 76Ge, 76,82Se, and 90,92Zr, and compared the results with the available experimental data. The GT strength distributions were sensitive to the deformation parameter as well as its sign, i.e., oblate or prolate. The Ikeda sum rule, which is usually thought to be satisfied under the one-body current approximation, regardless of nucleon models, was used to test our numerical calculations and shown to be satisfied without introducing the quenching factor, if high-lying GT excited states were properly taken into account. Most of the GT strength distributions of the nuclei considered in this work have the high-lying GT excited states beyond one-nucleon threshold, which are shown to be consistent with the available experimental data.
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Ha, Eunja; Cheoun, Myung-Ki [Soongsil University, Origin of Matter and Evolution of Galaxy Institute and Department of Physics, Seoul (Korea, Republic of)
2017-02-15
We investigated Gamow-Teller (GT) transitions and strength distributions of s-d shell N = Z nuclei, {sup 24}Mg, {sup 28}Si, and {sup 32}S, by a deformed quasi-particle random phase approximation (DQRPA). In the DQRPA, we included particle model space up to p-f shell and considered explicitly the deformation as well as the like- and unlike-pairing correlations. Shell evolution by deformation and attractive force by unlike-pairing correlations turned out to play vital roles to reproduce the experimental GT data. Correlations between the deformation and the pairing correlations are also discussed with the comparison to the experimental data shape. (orig.)
Isospin symmetry of Tz =±3/2→±1/2 Gamow-Teller transitions in A=41 nuclei
Fujita, Y.; Shimbara, Y.; Adachi, T.; Berg, G. P.; Brown, B. A.; Fujita, H.; Hatanaka, K.; Kamiya, J.; Nakanishi, K.; Sakemi, Y.; Sasaki, S.; Shimizu, Y.; Tameshige, Y.; Uchida, M.; Wakasa, T.; Yosoi, M.
2004-11-01
Under the assumption that isospin T is a good quantum number, isobaric analog states and various analogous transitions are expected in isobars with mass number A . The strengths of Tz =±3/2→±1/2 analogous Gamow-Teller (GT) transitions and analogous M1 transitions within the A=41 isobar quartet are compared in detail. The Tz =+3/2→+1/2 GT transitions from the Jπ = 3/2+ ground state of 41K leading to excited Jπ = 1/2+ , 3/2+ , and 5/2+ states in 41Ca were measured using the ( 3He ,t) charge-exchange reaction. With a high energy resolution of 35 keV , many fragmented states were observed, and the GT strength distribution was determined up to 10 MeV excitation energy ( Ex ) . The main part of the strength was concentrated in the Ex =4 6 MeV region. A shell-model calculation could reproduce the concentration, but not so well details of the strength distribution. The obtained distribution was further compared with two results of 41Ti β decay studying the analogous Tz =-3/2→-1/2 GT strengths. They reported contradicting distributions. One-to-one correspondences of analogous transitions and analog states were assigned up to Ex =6 MeV in the comparison with one of these 41Ti β -decay results. Combining the spectroscopic information of the analog states in 41Ca and 41Sc , the most probable Jπ values were deduced for each pair of analog states. It was found that 5/2+ states carry the main part of the observed GT strength, while much less GT strength was carried by 1/2+ and 3/2+ states. The gross features of the GT strength distributions for each J were similar for the isospin analogous Tz =±3/2→±1/2 transitions, but the details were somewhat different. From the difference of the distributions, isospin-asymmetry matrix elements of ≈8 keV were deduced. The Coulomb displacement energy, which is sensitive to the configuration of states, showed a sudden increase of about 50 keV at the excitation energy of 3.8 MeV . The strengths of several M1 transitions to the
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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.
Measurement of Gamow-Teller and spin dipole strength in the 45Sc(n,p)45Ca reaction at 198 MeV
International Nuclear Information System (INIS)
Alford, W.P.; Celler, A.; Brown, B.A.; Long, S.; Raywood, K.
1990-11-01
The reaction 45 Sc(n,p) 45 Ca has been studied at an energy of 198 MeV with energy resolution of about 1 MeV. Measurements were carried out at nominal angles 0, 3, 6, 9, 12, 15, and 18 degrees and spectra obtained up to ∼40 MeV excitation energy in 45 Ca. Significant Gamow-Teller strength is observed at an excitation energy of about 7 MeV, somewhat higher than predicted by shell model calculations. The strength observed is in agreement with calculations using g A /g V ≅ 1. The spin dipole giant resonance is seen with centroid at about 15 MeV excitation and total cross section of 25 mb/sr at an angle of 6 degrees. (Author) (22 refs., 9 figs.)
Konieczka, M.; Kortelainen, M.; Satuła, W.
2018-03-01
Background: The atomic nucleus is a unique laboratory in which to study fundamental aspects of the electroweak interaction. This includes a question concerning in medium renormalization of the axial-vector current, which still lacks satisfactory explanation. Study of spin-isospin or Gamow-Teller (GT) response may provide valuable information on both the quenching of the axial-vector coupling constant as well as on nuclear structure and nuclear astrophysics. Purpose: We have performed a seminal calculation of the GT response by using the no-core configuration-interaction approach rooted in multireference density functional theory (DFT-NCCI). The model treats properly isospin and rotational symmetries and can be applied to calculate both the nuclear spectra and transition rates in atomic nuclei, irrespectively of their mass and particle-number parity. Methods: The DFT-NCCI calculation proceeds as follows: First, one builds a configuration space by computing relevant, for a given physical problem, (multi)particle-(multi)hole Slater determinants. Next, one applies the isospin and angular-momentum projections and performs the isospin and K mixing in order to construct a model space composed of linearly dependent states of good angular momentum. Eventually, one mixes the projected states by solving the Hill-Wheeler-Griffin equation. Results: The method is applied to compute the GT strength distribution in selected N ≈Z nuclei including the p -shell 8Li and 8Be nuclei and the s d -shell well-deformed nucleus 24Mg. In order to demonstrate a flexibility of the approach we present also a calculation of the superallowed GT β decay in doubly-magic spherical 100Sn and the low-spin spectrum in 100In. Conclusions: It is demonstrated that the DFT-NCCI model is capable of capturing the GT response satisfactorily well by using a relatively small configuration space, exhausting simultaneously the GT sum rule. The model, due to its flexibility and broad range of applicability, may
International Nuclear Information System (INIS)
Scholl, Clemens
2010-01-01
Excited states in the light nuclei 9 B and 13 C were studied using the ( 3 He,t) charge-exchange reaction on 9 Be and 13 C targets. The measurements were performed at the research center for nuclear physics (RCNP) in Osaka, Japan, using the magnetic spectrometer Grand Raiden and the dispersive WS course. The 3 He beam with an energy of 420 MeV was accelerated by the RCNP Ring Cyclotron. The Grand Raiden spectrometer and the WS course allow to study the ( 3 He,t) charge-exchange reaction with an energy resolution of around 30 keV, which is one order of magnitude better than measurements with the (p,n) charge-exchange reaction. The high resolution allows to better separate individual states and to determine weak excitation strengths because of low background in the spectra. A total of 19 states in 13 N were studied, and a total of 20 states were observed in 9 B. Of these, 9 states in 13 C and 10 states in 9 B were identified as being excited by a Gamow-Teller transition. Charge-exchange reactions are related to beta-decay, and at zero momentum transfer a simple proportionality exists between the cross-section of the charge-exchange experiment and the Fermi (F) or Gamow-Teller (GT) beta-decay strength. While the Fermi strength B(F) is concentrated in the transition to the isobaric analog state, the Gamow-Teller strength B(GT) is scattered among the excited states. The main aim of the present study is to determine the B(GT) strengths in the nuclei 9 B and 13 N. The only charge-exchange study of 9 B was made 30 years ago with the (p,n) reaction and a resolution of around 300-400 keV. Many states, especially at high excitation energy, could not be resolved by that study. The present work was able to separate many weakly excited states with small decay width at high excitation energies (12-19 MeV) in 9 B and determine the B(GT) strength distribution by using recent high-precision beta-decay data. The results point to a strong difference in spatial structure between the
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Scholl, Clemens
2010-07-07
Excited states in the light nuclei {sup 9}B and {sup 13}C were studied using the ({sup 3}He,t) charge-exchange reaction on {sup 9}Be and {sup 13}C targets. The measurements were performed at the research center for nuclear physics (RCNP) in Osaka, Japan, using the magnetic spectrometer Grand Raiden and the dispersive WS course. The {sup 3}He beam with an energy of 420 MeV was accelerated by the RCNP Ring Cyclotron. The Grand Raiden spectrometer and the WS course allow to study the ({sup 3}He,t) charge-exchange reaction with an energy resolution of around 30 keV, which is one order of magnitude better than measurements with the (p,n) charge-exchange reaction. The high resolution allows to better separate individual states and to determine weak excitation strengths because of low background in the spectra. A total of 19 states in {sup 13}N were studied, and a total of 20 states were observed in {sup 9}B. Of these, 9 states in {sup 13}C and 10 states in {sup 9}B were identified as being excited by a Gamow-Teller transition. Charge-exchange reactions are related to beta-decay, and at zero momentum transfer a simple proportionality exists between the cross-section of the charge-exchange experiment and the Fermi (F) or Gamow-Teller (GT) beta-decay strength. While the Fermi strength B(F) is concentrated in the transition to the isobaric analog state, the Gamow-Teller strength B(GT) is scattered among the excited states. The main aim of the present study is to determine the B(GT) strengths in the nuclei {sup 9}B and {sup 13}N. The only charge-exchange study of {sup 9}B was made 30 years ago with the (p,n) reaction and a resolution of around 300-400 keV. Many states, especially at high excitation energy, could not be resolved by that study. The present work was able to separate many weakly excited states with small decay width at high excitation energies (12-19 MeV) in {sup 9}B and determine the B(GT) strength distribution by using recent high-precision beta-decay data. The
q-Gamow states as continuous linear functionals on analytical test functions
Energy Technology Data Exchange (ETDEWEB)
Plastino, A.; Rocca, M.C., E-mail: mariocarlosrocca@gmail.com
2016-04-15
We define here q-Gamow states corresponding to Tsallis' q-statistics. We compute for them their norm, mean energy value and the q-analogue of the Breit–Wigner distribution (a q-Breit–Wigner).
Gamow state vectors as functionals over subspaces of the nuclear space
International Nuclear Information System (INIS)
Bohm, A.
1979-12-01
Exponentially decaying Gamow state vectors are obtained from S-matrix poles in the lower half of the second sheet, and are defined as functionals over a subspace of the nuclear space, PHI. Exponentially growing Gamow state vectors are obtained from S-matrix poles in the upper half of the second sheet, and are defined as functionals over another subspace of PHI. On functionals over these two subspaces the dynamical group of time development splits into two semigroups
Energy Technology Data Exchange (ETDEWEB)
Deloncle, I. [CSNSM, CNRS et Universite Paris-Sud, Orsay (France); CEA, DAM, DIF, Arpajon (France); Peru, S. [CEA, DAM, DIF, Arpajon (France); Martini, M. [ESNT, CEA-Saclay, DSM, Irfu, Service de Physique Nucleaire, Gif-sur-Yvette (France)
2017-08-15
In this paper we present theoretical results on the dipole response in the proton spin-saturated {sup 90-94}Zr isotopes. The electric and magnetic dipole excitations are obtained in Hartree-Fock-Bogolyubov plus Quasi-particle Random Phase Approximation (QRPA) calculations performed with the D1M Gogny force. A pnQRPA charge exchange code is used to study the Gamow-Teller response. The results on the pygmy, the giant dipole resonances as well as those on the magnetic nuclear spin-flip excitation and the Gamow-Teller transitions are compared with available experimental or theoretical information. In our approach, the proton pairing plays a role in the phonon excitations, in particular in the M1 nuclear spin-flip resonance. (orig.)
International Nuclear Information System (INIS)
Mercer, D.J.
1993-01-01
Measurements of neutron polarization from (rvec p,rvec n) reactions can provide valuable clues toward understanding the isovector nucleon-nucleus interaction. A neutron time-of-flight polarimeter has been constructed at the Los Alamos Meson Physics Facility to perform such measurements, but before the polarimeter can be used, its effective analyzing powers must be determined. This is accomplished by using the 14 C(rvec p,rvec n) 14 N reaction at a bombarding energy of 494 MeV to produce a beam of neutrons with known polarization, illuminating the detector with these neutrons, and measuring the azimuthal asymmetries after scattering from a hydrogenous analyzer fluid within the detector. Secondary measurements are made using the 2 H(rvec p,rvec n) 2 p reaction with bombarding energies of 318 and 494 MeV to produce a polarized neutron beam. The results from (rvec np) analyzing reactions within the detector agree with values anticipated from free nucleon-nucleon analyzing powers, but the results from (rvec np) analyzing reactions display a more than 33% reduction from the anticipated values. Additionally, measurements are made of the polarization transfer coefficient D LL (0 degree) for rvec p,rvec n Gamow-Teller reactions on 2 H, 7 Li 12 C, and 14 C targets. For a purely central interaction, one would expect that D LL (0 degree) ∼ -1/3 in the plane wave limit, but a simple average of the Jπ = 0 + → 1 + results at a bombardment energy of 494 MeV gives D LL (0 degree) = -0.689 ± 0.044. Thus, the measurements indicate that the nucleon-nucleus interaction -- which is largely central at 200 MeV -- has strong tensor contributions at higher energy
Semi-classical behavior of Poschl-Teller coherent states
Czech Academy of Sciences Publication Activity Database
Bergeron, H.; Gazeau, J.P.; Siegl, Petr; Youssef, A.
2010-01-01
Roč. 92, č. 6 (2010), s. 60003 ISSN 0295-5075 R&D Projects: GA MŠk LC06002 Institutional research plan: CEZ:AV0Z10480505 Institutional support: RVO:61389005 Keywords : coherent states * Pöschl-Teller potential * quantization Subject RIV: BE - Theoretical Physics Impact factor: 2.753, year: 2010
Classical motion and coherent states for Poeschl-Teller potentials
International Nuclear Information System (INIS)
Cruz y Cruz, S.; Kuru, S.; Negro, J.
2008-01-01
The trigonometric and hyperbolic Poeschl-Teller potentials are dealt with from the point of view of classical and quantum mechanics. We show that there is a natural correspondence between the algebraic structure of these two approaches for both kind of potentials. Then, the coherent states are constructed and the appropriate classical variables are compared with the expected values of their corresponding quantum operators
Allowed Gamow-Teller excitations from the ground state of N-14
Czech Academy of Sciences Publication Activity Database
Aroua, S.; Navrátil, Petr; Zamick, L.; Fayche, M. S.; Barret, B. R.; Vary, J. P.; Heyde, K.
2003-01-01
Roč. 720, 1/2 (2003), s. 71-83 ISSN 0375-9474 Institutional research plan: CEZ:AV0Z1048901 Keywords : core shell-model * tensor interactions * light-nuclei Subject RIV: BE - Theoretical Physics Impact factor: 1.761, year: 2003
Gamow-Teller matrix elements from the C-12(d,He-2) and Mg-24(d,He-2) reactions at 170 MeV
Baumer, C; Frekers, D; Schmidt, R; van den Berg, AM; Hannen, VM; Harakeh, MN; de Huu, MA; Wörtche, HJ; De Frenne, D; Hagemann, M; Heyse, J; Jacobs, E; Fujita, Y
The Mg-24(d,He-2)Na-24 and the C-12(d,He-2)B-12 charge-exchange reactions have been studied at an incident energy of 170 MeV. The two protons in the S-1(0)(pp) state (indicated as He-2) were both momentum analyzed and detected by the same spectrometer and detector. Background-free He-2 spectra with
George Gamow: a most talented and creative scientist
International Nuclear Information System (INIS)
Yang Qingyu
2002-01-01
As one of the most prominent scientists of the 20th century, George Gamow made notable contributions to many fields of science in his life time. In nuclear physics he proposed the well known 'nuclear potential barrier channel effect' and the Gamow-Teller transition probability of beta decay. In cosmology he did his almost to advocate the 'big bang' theory. Through extraordinary intuition he proposed a theory about how genetic codes work in molecular biology, which was later verified by Watson, Crick and Nirenbery. Gamow's unique style of research and his spirit of bringing forth new ideas in interdisciplinary subjects has greatly benefited scientific research
New SUSYQM coherent states for Pöschl-Teller potentials: a detailed mathematical analysis
Bergeron, H.; Siegl, P.; Youssef, A.
2012-06-01
In a recent short note (Bergeron et al 2010 Europhys. Lett. 92 60003), we have presented the good properties of a new family of semi-classical states for Pöschl-Teller potentials. These states are built from a supersymmetric quantum mechanics (SUSYQM) approach and the parameters of these ‘coherent’ states are points in the classical phase space. In this paper, we develop all the mathematical aspects that have been left out of the previous paper (proof of the resolution of unity, detailed calculations of the quantized version of classical observables and mathematical study of the resulting operators: problems of domains, self-adjointness or self-adjoint extensions). Some additional questions such as asymptotic behavior are also studied. Moreover, the framework is extended to a larger class of Pöschl-Teller potentials. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Coherent states: mathematical and physical aspects’.
Controllability of pure states for the Poeschl-Teller potential with a dynamical group SU(2)
International Nuclear Information System (INIS)
Dong, S.-H.; Tang Yu; Sun, G.-H.; Lara-Rosano, F.; Lozada-Cassou, M.
2005-01-01
The controllability of a quantum system for the modified Poeschl-Teller (MPT) potential with the discrete bound states is investigated. The creation and annihilation operators of this potential are constructed directly from the normalized wave function with the factorization method and associated to an su(2) algebra. It is shown that this quantum system with the nondegenerate discrete bound states can, in principle, be strongly completely controllable, i.e., the system eigenstates can be guided by the external field to approach arbitrarily close to a target state, which could be theoretically realized by the actions of the creation and annihilation operators on the ground state
New SUSYQM coherent states for Pöschl–Teller potentials: a detailed mathematical analysis
International Nuclear Information System (INIS)
Bergeron, H; Siegl, P; Youssef, A
2012-01-01
In a recent short note (Bergeron et al 2010 Europhys. Lett. 92 60003), we have presented the good properties of a new family of semi-classical states for Pöschl–Teller potentials. These states are built from a supersymmetric quantum mechanics (SUSYQM) approach and the parameters of these ‘coherent’ states are points in the classical phase space. In this paper, we develop all the mathematical aspects that have been left out of the previous paper (proof of the resolution of unity, detailed calculations of the quantized version of classical observables and mathematical study of the resulting operators: problems of domains, self-adjointness or self-adjoint extensions). Some additional questions such as asymptotic behavior are also studied. Moreover, the framework is extended to a larger class of Pöschl–Teller potentials. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Coherent states: mathematical and physical aspects’. (paper)
Jahn-Teller effect in Rydberg series: A multi-state vibronic coupling problem
International Nuclear Information System (INIS)
Staib, A.; Domcke, W.; Sobolewski, A.L.
1990-01-01
Two simple limiting cases of Jahn-Teller (JT) coupling in Rydberg states of polyatomic molecules are considered, namely (i) JT coupling in Rydberg orbitals as well as in the ionization continuum (nondegenerate ion core, degenerate Rydberg series) and (ii) JT coupling in the ion core (degenerate ion core, nondegenerate Rydberg series). For both models simple and efficient algorithms for the computation of spectra (dynamical JT effect) are developed. The orbital JT effect is shown to represent a novel type of multi-state vibronic coupling, giving rise to interesting spectroscopic phenomena, among them resonant inter-Rydberg perturbations and JT induced autoionization. Particular attention is paid to the demonstration of the characteristic spectroscopic signatures of the two types of JT coupling in Rydberg states. (orig.)
Edward Teller Biographical Memoir
Energy Technology Data Exchange (ETDEWEB)
Libby, S B; Sessler, A M
2009-07-27
Edward Teller died on September 9, 2003 in Stanford, California at the age of 95. He was both one of the great theoretical physicists of the twentieth century and a leading figure in the development of nuclear weapons and broader defense advocacy. Teller's work in physics, spanning many decades of the twentieth century, includes some of the most fundamental insights in the quantum behaviors of molecules and their spectra, nuclei, surfaces, solid state and spin systems, and plasmas. In the defense arena, Teller is best known for his key insight that made thermonuclear weapons possible. Teller was both a great scientific collaborator and physics teacher at all levels, known for his openness, generosity, personal warmth, and powerful physical intuition. Many of his graduate students went on to illustrious careers.
Gamow-Teller strength functions and neutrino problems
International Nuclear Information System (INIS)
Haxton, W.C.
1982-01-01
A quantitative understanding of spin strengths in nuclei is of vital importance in studies of nuclear double beta decay and in solar neutrino spectroscopy. The current status of these problems is outlined
New SUSYQM coherent states for Poschl-Teller potentials: a detailed mathematical analysis
Czech Academy of Sciences Publication Activity Database
Bergeron, H.; Siegl, Petr; Youssef, A.
2012-01-01
Roč. 45, č. 24 (2012), 244028/1-244028/14 ISSN 1751-8113 R&D Projects: GA MŠk LC06002; GA ČR GAP203/11/0701 Institutional support: RVO:61389005 Keywords : supersymmetry * Poschi-Teller potential Subject RIV: BE - Theoretical Physics Impact factor: 1.766, year: 2012
International Nuclear Information System (INIS)
Hakimyfard, A.; Barseghyan, M.G.; Kirakosyan, A.A.; Duque, C.A.
2010-01-01
Influence of the electric field and hydrostatic pressure on the electronic states in a Poschl-Teller quantum well is studied. In the framework of variational method the dependences of the ground state energy on the electric field and hydrostatic pressure are calculated for different values of the potential parameters and the temperature. It is shown that the increase in the electric field leads to the increase in the ground state energy, while the increase in the well width leads to the strengthening of the electric field effect. The ground state energy decreases with increasing pressure and increases with increasing temperature
George Gamow: Scientific Amateur and Polymath
Harper, Eamon
George Gamow (1904-1968) was among the first of the many brilliant scientists who forsook Europe for the United States in the early 1930s. Although most were fleeing the fascist imperium of Hitler and Mussolini, Gamow was one of a few who managed to escape the burgeoning despotism of Stalin in the Soviet Union. His early application of quantum mechanics to the atomic nucleus and his subsequent insight into the role played by the physics of the atom and its nucleus in stars, galaxies, and the universe identifies him as a scientist of unusual genius. Gamow displayed a boisterous, infectious - almost Rutherfordian - interest in all aspects of pure science. His interests were broad and his industry prodigious. His scientific output covered areas as diverse as nuclear physics, astrophysics, cosmology, biological genetics, and the fascinating question of the relationship of the large-scale structure and development of the universe to the properties of elementary particles and fields. He also was an immensely imaginative and prolific author of popular expositions on scientific subjects. One who is as well-known for his authorship of the Mr. Tompkins series of science popularizations as for his contributions to the development of the physical consequences of the big-bang theory of the expanding universe and the prediction of the cosmic background radiation must be unique in the scientific pantheon.
Barakat, Khaldoon A; Cundari, Thomas R; Omary, Mohammad A
2003-11-26
DFT calculations were used to optimize the phosphorescent excited state of three-coordinate [Au(PR3)3]+ complexes. The results indicate that the complexes rearrange from their singlet ground-state trigonal planar geometry to a T-shape in the lowest triplet luminescent excited state. The optimized structure of the exciton contradicts the structure predicted based on the AuP bonding properties of the ground-state HOMO and LUMO. The rearrangement to T-shape is a Jahn-Teller distortion because an electron is taken from the degenerate e' (5dxy, 5dx2-y2) orbital upon photoexcitation of the ground-state D3h complex. The calculated UV absorption and visible emission energies are consistent with the experimental data and explain the large Stokes' shifts while such correlations are not possible in optimized models that constrained the exciton to the ground-state trigonal geometry.
International Nuclear Information System (INIS)
Muramatsu, Y.; Ueda, K.; Chiba, H.; Saito, N.; Lavollee, M.; Czasch, A.; Weber, T.; Jagutzki, O.; Schmidt-Boecking, H.; Moshammer, R.; Becker, U.; Kubozuka, K.; Koyano, I.
2002-01-01
The doubly degenerate core-excited Π state of CO 2 splits into two due to static Renner-Teller effect. Using the triple-ion-coincidence momentum imaging technique and focusing on the dependence of the measured quantities on the polarization of the incident light, we have probed, directly and separately, the linear and bent geometries for the B 1 and A 1 Renner-Teller pair states, as a direct proof of the static Renner-Teller effect
Conduction band-edge d-states in high-k dielectrics due to Jahn-Teller term splittings
International Nuclear Information System (INIS)
Lucovsky, G.; Fulton, C.C.; Zhang, Y.; Luning, J.; Edge, L.; Whitten, J.L.; Nemanich, R.J.; Schlom, D.G.; Afanase'v, V.V.
2005-01-01
X-ray absorption spectroscopy (XAS) is used to study conduction band edge electronic structure of high-k transition metal (TM) and trivalent lanthanide series rare earth (RE) oxide dielectrics. Empty TM/RE d-states are studied by intra-atomic transitions originating in core level spin-orbit split p-states, and conduction band states are studied in inter-atomic transitions which originate in the oxygen atom 1s core level state. In non-crystalline Zr and Hf silicate alloys, the local bonding symmetry, or crystal field splits these d-states into doubly and triply degenerate features. In nano-crystalline oxides, there are additional d-state splittings due to contributions of more distant neighbors that completely remove d-state degeneracies via the Jahn-Teller effect mechanism. This gives rise to highly localized band edge states that are electronically active in photoconductivity, internal photoemission, and act as bulk traps in metal oxide semiconductor (MOS) devices
Gamow–Teller 1+ states in 112−124Sb isotopes
Indian Academy of Sciences (India)
section is dominated by GT transitions with ∆L = 0, ∆S = 1 and ∆Jπ = 1+. The cross-section, extrapolated to zero-momentum transfer, is proportional to the GT strength between the same states. Out of these reactions, the (p, n) reaction is the most common, and for several years, this was used successfully in the investigation.
Varandas, A J C; Sarkar, B
2011-05-14
Generalized Born-Oppenheimer equations including the geometrical phase effect are derived for three- and four-fold electronic manifolds in Jahn-Teller systems near the degeneracy seam. The method is readily extendable to N-fold systems of arbitrary dimension. An application is reported for a model threefold system, and the results are compared with Born-Oppenheimer (geometrical phase ignored), extended Born-Oppenheimer, and coupled three-state calculations. The theory shows unprecedented simplicity while depicting all features of more elaborated ones.
George Gamow and the Genetic Code
Indian Academy of Sciences (India)
cause they were held together by hydrogen bonds formed be- tween adenine and ... To return to our story, on the 8th of July Gamow addressed a letter to Watson and ... "For example, the animal will be a cat if Adenine is always followed by ...
Liu, R. M.; Zhuo, W. Z.; Chen, J.; Qin, M. H.; Zeng, M.; Lu, X. B.; Gao, X. S.; Liu, J.-M.
2017-07-01
We study the thermal phase transition of the fourfold degenerate phases (the plaquette and single-stripe states) in the two-dimensional frustrated Ising model on the Shastry-Sutherland lattice using Monte Carlo simulations. The critical Ashkin-Teller-like behavior is identified both in the plaquette phase region and the single-stripe phase region. The four-state Potts critical end points differentiating the continuous transitions from the first-order ones are estimated based on finite-size-scaling analyses. Furthermore, a similar behavior of the transition to the fourfold single-stripe phase is also observed in the anisotropic triangular Ising model. Thus, this work clearly demonstrates that the transitions to the fourfold degenerate states of two-dimensional Ising antiferromagnets exhibit similar transition behavior.
Relativistic Jahn-Teller effect in tetrahedral systems
International Nuclear Information System (INIS)
Opalka, Daniel; Domcke, Wolfgang; Segado, Mireia; Poluyanov, Leonid V.
2010-01-01
It is shown that orbitally degenerate states in highly symmetric systems are split by Jahn-Teller forces which are of relativistic origin (that is, they arise from the spin-orbit coupling operator). For the example of tetrahedral systems, the relativistic Jahn-Teller Hamiltonians of orbitally degenerate electronic states with spin 1/2 are derived. While both electrostatic and relativistic forces contribute to the Jahn-Teller activity of vibrational modes of E and T 2 symmetry in 2 T 2 states of tetrahedral systems, the electrostatic and relativistic Jahn-Teller couplings are complementary for 2 E states: The E mode is Jahn-Teller active through electrostatic forces, while the T 2 mode is Jahn-Teller active through the relativistic forces. The relativistic Jahn-Teller parameters have been computed with ab initio relativistic electronic-structure methods. It is shown for the example of the tetrahedral cluster cations of the group V elements that the relativistic Jahn-Teller couplings can be of the same order of magnitude as the familiar electrostatic Jahn-Teller couplings for the heavier elements.
Gamow on Newton: Another Look at Centripetal Acceleration
Corrao, Christian
2012-01-01
Presented here is an adaptation of George Gamow's derivation of the centripetal acceleration formula as it applies to Earth's orbiting Moon. The derivation appears in Gamows short but engaging book "Gravity", first published in 1962, and is essentially a distillation of Newton's work. While "TPT" contributors have offered several insightful…
On the Time-Dependent Analysis of Gamow Decay
Durr, Detlef; Grummt, Robert; Kolb, Martin
2011-01-01
Gamow's explanation of the exponential decay law uses complex "eigenvalues" and exponentially growing "eigenfunctions". This raises the question, how Gamow's description fits into the quantum mechanical description of nature, which is based on real eigenvalues and square integrable wavefunctions. Observing that the time evolution of any…
Description of the Gamov-Teller β+-decay of tin isotopes
International Nuclear Information System (INIS)
Kuz'min, V.A.; Solov'ev, V.G.
1988-01-01
The integrated log(ft) values of Gamow-Teller β + decays of the neutron-deficient tine isotopes are calculated in the random phase approximation with particle-hole and particle-particle residual interactions which parameters have been fixed earlier. For |g A /g V |=1 and |g A /g V |=1.263 a good correspondence with the experimental data is obtained for 104,106,108 Sn and a prediction is made for 102 Sn. It is shown that one cannot define from the rate of neutron-deficient nuclei β + decay the renormalization of the axial-vector weak interaction constant g A
International Nuclear Information System (INIS)
Pradhan, B.; Mohanta, K.L.; Rout, G.C.
2012-01-01
We report here a mean-field study of competing antiferromagnetism, superconductivity and lattice strain phases and their effect on the local density of states of the cuprate system. Our model Hamiltonian incorporating these interactions is reported earlier [G.C. Rout et al., Physica C, 2007]. The analytic expression for superconducting, antiferromagnetism and lattice strain order parameters are calculated and solved self-consistently. The interplay of these order parameters is investigated considering the calculated density of states (DOSs) of the conduction electrons. The DOS displays multiple gap structures with multiple peaks. It is suggested that the tunneling conductance data obtained from the scanning tunneling microscopy (STM) measurements could be interpreted by using the quasi-particle bands calculated from our model Hamiltonian. We have discussed the mechanism to calculate the order parameters from the conductance data.
Byrne, Owen; McCaffrey, John G
2011-03-28
Absorption spectroscopy recorded for annealed samples of matrix-isolated atomic europium reveals a pair of thermally stable sites in Ar and Kr while a single site exists in Xe. Plots of the matrix shifts of the visible s → p bands versus host polarizability, allowed the association of the single site in Xe and the blue sites in Ar and Kr. On the basis of the similar ground state bond lengths expected for the Eu-rare gas (RG) diatomics and the known Na-RG molecules, the blue sites are attributed to Eu occupancy in the smaller tetra-vacancy while the red sites are proposed to arise from hexa-vacancy sites. Both sites are of cubic symmetry, consistent with the pronounced Jahn-Teller structure present on the y(8)P ← a(8)S(7/2) transition for these bands in the three hosts studied. Site-selective excitation spectroscopy has been used to reanalyze complex absorption spectra previously published by Jakob et al. [Phys. Lett. A 57, 67 (1976)] for the near-UV f → d transitions. On the basis that a pair of thermally stable sites exist in solid argon, the occurrence of crystal field splitting has been identified to occur for the J ≥ 5/2 level of the (8)P state when isolated in these two sites with cubic symmetry. From a detailed lineshape analysis, the magnitude of the crystal field splittings on the J = 5/2 level in Ar is found to be 105 and 123 cm(-1) for the red and blue sites, respectively.
96 THE EFFECT OF AUTOMATED TELLER MACHINES ON BANKS ...
African Journals Online (AJOL)
reduces the number of human deployment by banks thereby reducing cost of operations. ... United States (PLUS and CIRRUS) drooped their long standing opposition to allowing ..... Automated teller machine network pricing – A review of the.
Realistic Gamow shell model for resonance and continuum in atomic nuclei
Xu, F. R.; Sun, Z. H.; Wu, Q.; Hu, B. S.; Dai, S. J.
2018-02-01
The Gamow shell model can describe resonance and continuum for atomic nuclei. The model is established in the complex-moment (complex-k) plane of the Berggren coordinates in which bound, resonant and continuum states are treated on equal footing self-consistently. In the present work, the realistic nuclear force, CD Bonn, has been used. We have developed the full \\hat{Q}-box folded-diagram method to derive the realistic effective interaction in the model space which is nondegenerate and contains resonance and continuum channels. The CD-Bonn potential is renormalized using the V low-k method. With choosing 16O as the inert core, we have applied the Gamow shell model to oxygen isotopes.
Andrew Liehr and the structure of Jahn-Teller surfaces
International Nuclear Information System (INIS)
Chibotaru, Liviu F.; Iwahara, Naoya
2017-01-01
The present article is an attempt to draw attention to a seminal work by Andrew Liehr “Topological aspects of conformational stability problem” [1, 2] issued more than half century ago. The importance of this work stems from two aspects of static Jahn-Teller and pseudo-Jahn-Teller problems fully developed by the author. First, the work of Liehr offers an almost complete overview of adiabatic potential energy surfaces for most known Jahn-Teller problems including linear, quadratic and higher-order vibronic couplings. Second, and most importantly, it identifies the factors defining the structure of Jahn-Teller surfaces. Among them, one should specially mention the minimax principle stating that the distorted Jahn-Teller systems tend to preserve the highest symmetry consistent with the loss of their orbital degeneracy. We believe that the present short reminiscence not only will introduce a key Jahn-Teller scientist to the young members of the community but also will serve as a vivid example of how a complete understanding of a complex problem, which the Jahn-Teller effect certainly was in the beginning of 1960s, can be achieved. (paper)
Gamow-Jordan vectors and non-reducible density operators from higher-order S-matrix poles
International Nuclear Information System (INIS)
Bohm, A.; Loewe, M.; Maxson, S.; Patuleanu, P.; Puentmann, C.; Gadella, M.
1997-01-01
In analogy to Gamow vectors that are obtained from first-order resonance poles of the S-matrix, one can also define higher-order Gamow vectors which are derived from higher-order poles of the S-matrix. An S-matrix pole of r-th order at z R =E R -iΓ/2 leads to r generalized eigenvectors of order k=0,1,hor-ellipsis,r-1, which are also Jordan vectors of degree (k+1) with generalized eigenvalue (E R -iΓ/2). The Gamow-Jordan vectors are elements of a generalized complex eigenvector expansion, whose form suggests the definition of a state operator (density matrix) for the microphysical decaying state of this higher-order pole. This microphysical state is a mixture of non-reducible components. In spite of the fact that the k-th order Gamow-Jordan vectors has the polynomial time-dependence which one always associates with higher-order poles, the microphysical state obeys a purely exponential decay law. copyright 1997 American Institute of Physics
Isospin mixing in the ground state of sup 5 sup 2 Mn
Schuurmans, P; Phalet, T; Severijns, N; Vereecke, B; Versyck, S
2000-01-01
The presence of isospin mixing into the ground state of sup 5 sup 2 Mn was studied via anisotropic positron emission from nuclei. With this method the isospin forbidden Fermi-component in the Gamow-Teller dominated beta decay was determined. It is shown that sample purity and the control of positron scattering is of vital importance. Comparison between theory and experiment shows that shell model calculations of the isospin mixing probability deviate by a factor three to seven from experiment. For more recent Hartree-Fock-RPA based calculations the difference is over two orders of magnitude.
Chernin, Artur D.
1994-08-01
In a paper published in 1953, i.e., more than a decade before the observational discovery of the cosmic microwave background radiation, George Gamow predicted theoretically the temperature of this radiation. He estimated it to be 7 K, which is very close to the subsequently measured value of about 3 K. Gamow found the present temperature of the background radiation on the basis of general formulas of cosmological dynamics. This prediction was in no way related to primordial nucleosynthesis.This circumstance has and is still causing misunderstanding in those cases in which the authors have raised doubts about Gamow's results, although an actual error has never been demonstrated. A detailed analysis makes it possible to understand how Gamow's calculation is possible. The problem lies in the fact that Gamow makes a certain additional implicit assumption which allows him to dispense with information on nucleosynthesis. This assumption is discussed in the context of the state of cosmology in the period from the fifties to the seventies, and of the current status of this branch of science.
And Gamow said, Let there be a Hot Universe
Indian Academy of Sciences (India)
Even further in the past, there would have been no space between the stars. .... then been known as the 'alpha, beta, gamma' paper. In the same ... Gamow assumed that the Universe is 3 billion years old (too small by a factor of 4 by current ...
Beta-decay of {sup 103}In: evidence for the Gamow-Teller resonance near {sup 100}Sn
Energy Technology Data Exchange (ETDEWEB)
Karny, M. [Warsaw Univ. (Poland). Inst. of Experimental Physics; Batist, L.; Brown, B.A. [and others
1998-04-01
The {beta} decay of the neutron-deficient isotope {sup 103}In was investigated by using total absorption {gamma}-ray spectrometry on mass-separated sources. The measurement reveals a high-lying resonance of the {beta}-decay strength in striking disagreement with high-resolution {gamma}-ray data. The result is discussed in comparison with shell-model predictions. (orig.)
Does the delta quench Gamow-Teller strength in (p,n)- and (p vector,p vector')-reactions
International Nuclear Information System (INIS)
Osterfeld, F.; Schulte, A.; Udagawa, T.; Yabe, M.
1986-01-01
Microscopic analyses of complete forward angle intermediate energy (p,n)-, ( 3 He,t)- and (p vector,p vector')-spin-flip spectra are presented for the reactions 90 Zr(p,n), 90 Zr( 3 He,t) and 90 Zr(p vector,p vector'). It is shown that the whole spectra up to high excitation energies (E X ∝50 MeV) are the result of correlated one-particle-one-hole (1p1h) spin-isospin transitions only. The spectra reflect, therefore, the linear spin-isospin response of the target nucleus to the probing external hadronic fields. Our results suggest that the measured (p,n)-, ( 3 He,t)- and (p vector,p vector')-cross sections are compatible with the transition strength predictions as obtained from random phase approximation (RPA) calculations. This means that the Δ isobar quenching mechanism is likely to be rather small. (orig.)
International Nuclear Information System (INIS)
Hauser, Andreas W.; Pototschnig, Johann V.; Ernst, Wolfgang E.
2015-01-01
Highlights: • Multireference and Coupled Cluster methods are applied to Na_3. • The PES is characterized by an analytical function fitted to ab initio data. • An effective rovibrational Hamiltonian is set up, with all parameters derived ab initio. • The coupling of pseudorotational tunneling and hyperfine interactions is investigated. • The theoretical predictions are compared to microwave spectra. - Abstract: The predictive capabilities of current ab initio approaches are tested in a benchmark study on the well known case of the Na_3 ground state. This molecule is small enough to be treated with computationally demanding methods, but also shows an interesting interplay between Jahn–Teller-, spin-orbit-, rovibrational- and hyperfine-interactions. The necessary parameters for the effective Hamiltonian are derived from the potential energy surface of the 1"2E′ ground state and from spin density evaluations at selected geometries, without any fitting adjustments to experimental data. We compare our results to highly resolved microwave spectra, with the aim to improve previous assignment attempts, where some parameters had to be estimated from fits to measured spectra.
The Phenalenyl Free Radical - a Jahn-Teller D3H PAH
O'Connor, G. D.; Troy, T. P.; Roberts, D. A.; Chalyavi, N.; Fückel, B.; Crossley, M. J.; Nauta, K.; Schmidt, T. W.; Stanton, J. F.
2012-06-01
After benzene and naphthalene, the smallest polycyclic aromatic hydrocarbon bearing six-membered rings is the threefold-symmetric phenalenyl radical. Despite the fact that it is so fundamental, its electronic spectroscopy has not been rigorously scrutinized, in spite of growing interest in graphene fragments for molecular electronic applications. Here we used complementary laser spectroscopic techniques to probe the jet-cooled phenalenyl radical in vacuo. Its spectrum reveals the interplay between four electronic states that exhibit Jahn-Teller and pseudo-Jahn-Teller (Herzberg-Teller) vibronic coupling. The coupling mechanism has been elucidated by the application of various ab initio quantum-chemical techniques.
12 CFR 205.16 - Disclosures at automated teller machines.
2010-01-01
... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Disclosures at automated teller machines. 205... SYSTEM ELECTRONIC FUND TRANSFERS (REGULATION E) § 205.16 Disclosures at automated teller machines. (a) Definition. Automated teller machine operator means any person that operates an automated teller machine at...
Energy Technology Data Exchange (ETDEWEB)
Pradhan, B. [Department of Physics, Govt. Science College, Malkangiri 764 048 (India); Mohanta, K.L. [Department of Physics, ITER, Siksha ' O' Anusandhan University, Bhubaneswar 751 030 (India); Rout, G.C., E-mail: gcr@iopb.res.in [Condensed Matter Physics Group, Dept. of Applied Physics and Ballistics, F.M. University, Balasore 756 019 (India)
2012-05-15
We report here a mean-field study of competing antiferromagnetism, superconductivity and lattice strain phases and their effect on the local density of states of the cuprate system. Our model Hamiltonian incorporating these interactions is reported earlier [G.C. Rout et al., Physica C, 2007]. The analytic expression for superconducting, antiferromagnetism and lattice strain order parameters are calculated and solved self-consistently. The interplay of these order parameters is investigated considering the calculated density of states (DOSs) of the conduction electrons. The DOS displays multiple gap structures with multiple peaks. It is suggested that the tunneling conductance data obtained from the scanning tunneling microscopy (STM) measurements could be interpreted by using the quasi-particle bands calculated from our model Hamiltonian. We have discussed the mechanism to calculate the order parameters from the conductance data.
The spin symmetry for deformed generalized Poeschl-Teller potential
International Nuclear Information System (INIS)
Wei Gaofeng; Dong Shihai
2009-01-01
In the case of spin symmetry we solve the Dirac equation with scalar and vector deformed generalized Poeschl-Teller (DGPT) potential and obtain exact energy equation and spinor wave functions for s-wave bound states. We find that there are only positive energy states for bound states in the case of spin symmetry based on the strong regularity restriction condition λ<-η for the wave functions. The energy eigenvalue approaches a constant when the potential parameter α goes to zero. Two special cases such as generalized PT potential and standard PT potential are also briefly discussed.
Lee, Myoung-Jae; Jung, Young-Dae
2017-01-01
The quantum shielding effects on the nuclear fusion reaction process are investigated in quantum plasmas. The closed expression of the classical turning point for the Gamow penetration factor in quantum plasmas is obtained by the Lambert W-function. The closed expressions of the Gamow penetration factor and the cross section for the nuclear fusion reaction in quantum plasmas are obtained as functions of the plasmon energy and the relative kinetic energy by using the effective interaction potential with the WKB analysis. It is shown that the influence of quantum screening suppresses the Sommerfeld reaction factor. It is also shown that the Gamow penetration factor increases with an increase of the plasmon energy. It is also shown that the quantum shielding effect enhances the deuterium formation by the proton-proton reaction in quantum plasmas. In addition, it is found that the energy dependences on the reaction cross section and the Gamow penetration factor are more significant in high plasmon-energy domains.
Jahn-Teller effect: its history and applicability
International Nuclear Information System (INIS)
Teller, E.
1981-01-01
The interactions between Teller, Renner, Jahn and Landau which led to the formulation of the Jahn-Teller effect are discussed. The applicability of Jahn-Teller type of theory to superconductivity and the explanation proposed by the use of Goldstone particles are assessed
78 FR 18221 - Disclosures at Automated Teller Machines (Regulation E)
2013-03-26
... Disclosures at Automated Teller Machines (Regulation E) AGENCY: Bureau of Consumer Financial Protection... the EFTA to eliminate a requirement that a fee notice be posted on or at automated teller machines... legislation, though the Electronic Fund Transfer Act and Regulation E use the term ``automated teller machine...
The vibrational Jahn–Teller effect in E⊗e systems
Energy Technology Data Exchange (ETDEWEB)
Thapaliya, Bishnu P.; Dawadi, Mahesh B.; Ziegler, Christopher; Perry, David S., E-mail: dperry@uakron.edu
2015-10-16
Highlights: • The vibrational Jahn–Teller effect is documented for three E⊗e molecular systems. • The spontaneous vibrational Jahn–Teller distortion is very small. • Vibrational Jahn–Teller splittings are substantial (1–60 cm{sup −1}). • Vibrational conical intersections in CH{sub 3}OH are accessible at low energies. - Abstract: The Jahn–Teller theorem is applied in the vibrational context where degenerate high-frequency vibrational states (E) are considered as adiabatic functions of low-frequency vibrational coordinates (e). For CH{sub 3}CN and Cr(C{sub 6}H{sub 6})(CO){sub 3}, the global minimum of the non-degenerate electronic potential energy surface occurs at the C{sub 3v} geometry, but in CH{sub 3}OH, the equilibrium geometry is far from the C{sub 3v} reference geometry. In the former cases, the computed spontaneous Jahn–Teller distortion is exceptionally small. In methanol, the vibrational Jahn–Teller interaction results in the splitting of the degenerate E-type CH stretch into what have been traditionally assigned as the distinct ν{sub 2} and ν{sub 9} vibrational bands. The ab initio vibrational frequencies are fit precisely by a two-state high-order Jahn–Teller Hamiltonian (Viel and Eisfeld, 2004). The presence of vibrational conical intersections, including 7 for CH{sub 3}OH, has implications for spectroscopy, for geometric phase, and for ultrafast localized non-adiabatic energy transfer.
Formal verification of automated teller machine systems using SPIN
Iqbal, Ikhwan Mohammad; Adzkiya, Dieky; Mukhlash, Imam
2017-08-01
Formal verification is a technique for ensuring the correctness of systems. This work focuses on verifying a model of the Automated Teller Machine (ATM) system against some specifications. We construct the model as a state transition diagram that is suitable for verification. The specifications are expressed as Linear Temporal Logic (LTL) formulas. We use Simple Promela Interpreter (SPIN) model checker to check whether the model satisfies the formula. This model checker accepts models written in Process Meta Language (PROMELA), and its specifications are specified in LTL formulas.
The T1u x 8 hg Jahn-Teller system - an improved model for the C60-molecule
International Nuclear Information System (INIS)
Rough, S.M.; Dunn, J.L.; Bates, C.A.
1997-01-01
The ground state of C 60 - gives rise to a T 1u x 8 h g Jahn-Teller (JT) system. A proof is presented showing that the presence of eight active h g modes rather than one makes little difference to the mathematical complexity of this problem compared to the simpler single-mode variant. After showing that the T 1u x 8 h g Jahn-Teller system has the same electronic eigenstates as the T 1u x h g Jahn-Teller system, the inversion splitting and first-order reduction factors are derived. (orig.)
International Nuclear Information System (INIS)
Fossez, Kevin
2014-01-01
Small open quantum systems, whose properties are profoundly affected by the environment of continuum states, are intensely studied in various fields of Physics: nuclear physics, atomic and molecular physics, quantum optics, etc. These different many-body systems, in spite of their specific features, have generic properties which are common to all weakly bound or unbound systems close to the threshold. Coupling to the continuum is essential to describe the low-energy nuclear reactions of astrophysical interest, the formation of halo states in nuclei, atomic clusters and dipolar anions, or the near-threshold two neutron and alpha particle correlations (clustering). Recently, the open quantum system extension of the nuclear shell model, the Gamow shell model (GSM), based on the Berggren ensemble, has been applied successfully for the description of resonant states spectra in atomic nuclei. The coupled-channel formulation of the GSM (GSM-CC) allows to describe various low-energy nuclear reactions. In this work, the GSM-CC is formulated and applied for the description of proton/neutron radiative capture reactions of astrophysical interest, such as: 17 F(p, γ) 18 Ne, 7 Be(p, γ) 8 B and 7 Li(n, γ) 8 Li. Moreover, for the first time, the GSM has been applied in atomic physics for the description of spectra of dipolar anions. Systematic investigation of the hydrogen cyanide dipolar anion (HCN - ) allowed to identify the collective bands of states both in the strong coupling regime, for weakly bound halo states, and in the weak coupling regime above the dissociation threshold. In the strong coupling regime, K J = 0 anion a rotational band has been found. Above the threshold, K J quantum number is not conserved. Resonances in this regime form rotational bands according to the angular momentum of the rotating molecule, whereas the band head energies and the lifetimes depend predominantly on the external electron wave function. (author) [fr
Jahn-Teller effect fundamentals and implications for physics and chemistry
Koppel, Horst; Barentzen, Heinz
2009-01-01
The Jahn-Teller effect continues to be a paradigm for structural instabilities and dynamical processes in molecules and in the condensed phase. While the basic theorem, first published in 1937, had to await experimental verification for 15 years, the intervening years have seen rapid development, initially in the theoretical arena, followed increasingly by experimental work on molecules and crystals. Among the many important developments in the field we mention cooperative phenomena in crystals, the general importance of pseudo-Jahn-Teller couplings for symmetry-lowering phenomena in molecular systems, nonadiabatic processes at conical intersections of potential energy surfaces and extensions of the basic theory in relation to the discovery of fullerenes and other icosahedral systems. The aim of the present volume is to provide a survey of the state-of-the art in Jahn-Teller interactions at the interface of quantum chemistry and condensed matter physics.
Benchmarking nuclear models for Gamow–Teller response
International Nuclear Information System (INIS)
Litvinova, E.; Brown, B.A.; Fang, D.-L.; Marketin, T.; Zegers, R.G.T.
2014-01-01
A comparative study of the nuclear Gamow–Teller response (GTR) within conceptually different state-of-the-art approaches is presented. Three nuclear microscopic models are considered: (i) the recently developed charge-exchange relativistic time blocking approximation (RTBA) based on the covariant density functional theory, (ii) the shell model (SM) with an extended “jj77” model space and (iii) the non-relativistic quasiparticle random-phase approximation (QRPA) with a Brueckner G-matrix effective interaction. We study the physics cases where two or all three of these models can be applied. The Gamow–Teller response functions are calculated for 208 Pb, 132 Sn and 78 Ni within both RTBA and QRPA. The strengths obtained for 208 Pb are compared to data that enable a firm model benchmarking. For the nucleus 132 Sn, also SM calculations are performed within the model space truncated at the level of a particle–hole (ph) coupled to vibration configurations. This allows a consistent comparison to the RTBA where ph⊗phonon coupling is responsible for the spreading width and considerable quenching of the GTR. Differences between the models and perspectives of their future developments are discussed.
Benchmarking nuclear models for Gamow–Teller response
Energy Technology Data Exchange (ETDEWEB)
Litvinova, E., E-mail: elena.litvinova@wmich.edu [Department of Physics, Western Michigan University, Kalamazoo, MI 49008-5252 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Brown, B.A. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-1321 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Fang, D.-L. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824-1321 (United States); Marketin, T. [Physics Department, Faculty of Science, University of Zagreb (Croatia); Zegers, R.G.T. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-1321 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824-1321 (United States)
2014-03-07
A comparative study of the nuclear Gamow–Teller response (GTR) within conceptually different state-of-the-art approaches is presented. Three nuclear microscopic models are considered: (i) the recently developed charge-exchange relativistic time blocking approximation (RTBA) based on the covariant density functional theory, (ii) the shell model (SM) with an extended “jj77” model space and (iii) the non-relativistic quasiparticle random-phase approximation (QRPA) with a Brueckner G-matrix effective interaction. We study the physics cases where two or all three of these models can be applied. The Gamow–Teller response functions are calculated for {sup 208}Pb, {sup 132}Sn and {sup 78}Ni within both RTBA and QRPA. The strengths obtained for {sup 208}Pb are compared to data that enable a firm model benchmarking. For the nucleus {sup 132}Sn, also SM calculations are performed within the model space truncated at the level of a particle–hole (ph) coupled to vibration configurations. This allows a consistent comparison to the RTBA where ph⊗phonon coupling is responsible for the spreading width and considerable quenching of the GTR. Differences between the models and perspectives of their future developments are discussed.
Analogy Between Particle in a Box and Jahn–Teller Effect
Indian Academy of Sciences (India)
IAS Admin
Solving the SchrÄodinger equation, the allowed energy levels of the particle are given .... to slight distortion of the cube. Using (3), the new energy of ... ARTICLE. The Jahn–Teller theorem states that in a nonlinear molecule, if degenerate orbitals are asymmetrically occupied a distortion will occur to remove the degeneracy.
Algebraic treatment of second Poeschl-Teller, Morse-Rosen and Eckart equations
International Nuclear Information System (INIS)
Barut, A.O.; Inomata, A.; Wilson, R.
1987-01-01
The method of algebraic treatment is applied to the non-compact case to solve a family of second Poeschl-Teller, Morse-Rosen and Eckart equations with quantized coupling constants. Both discrete and continuous spectra, bound state and scattering wave functions (transmission coefficients) are found from the matrix elements of group representations. (author). 24 refs, 1 tab
Jahn-Teller coupling at ND1 and GR1 centres in diamond
International Nuclear Information System (INIS)
Lowther, J.E.
1978-01-01
Stress parameters associated with the splitting of the GR1 and ND1 lines are examined in the light of the recent suggestion that ND1 arises from the negatively charged vacancy. The stress parameters are totally consistent with this interpretation; Jahn-Teller coupling in the excited states being similar for both centres. (author)
International Nuclear Information System (INIS)
Breza, M.
2003-01-01
A group-theoretical analysis of Jahn-Teller distortions using step-by-step symmetry descent method is based on consecutive removal of symmetry elements during electron degeneracy splitting. The results of this treatment imply that the Jahn-Teller effect in D 6h parent symmetry group may result in stable geometries of D 2h , D 2 , C 2h , C 2v , C 2 , C i , C s and/or C 1 symmetries. The Jahn-Teller effect in D 5h parent group may result in C 2v , C 2 , C s and/or C 1 stable geometries. All these symmetry groups may correspond to classical saddle points of Jahn-Teller energy hypersurfaces. Possible electronic states in these geometries may be also predicted. Such complex hypersurfaces cannot be described by the classical treatments based on Jahn-Teller active coordinates
1995 Edward teller lecture. Patience and optimism
International Nuclear Information System (INIS)
Miley, G.H.
1996-01-01
Remarks made in the author close-quote s acceptance lecture for the 1995 Edward Teller Medal are presented and expanded. Topics covered include research on nuclear-pumped lasers, the first direct e-beam-pumped laser, direct energy conversion and advanced fuel fusion, plus recent work on inertial electrostatic confinement. open-quote open-quote Patience close-quote close-quote and open-quote open-quote optimism close-quote close-quote are viewed as essential elements needed by scientists following the open-quote open-quote zig-zag close-quote close-quote path to fusion energy production. copyright 1996 American Institute of Physics
The Jahn-Teller effect and its observation in titanium alum
International Nuclear Information System (INIS)
Tregenna Piggott, P.
1996-01-01
Full text: A fundamental assumption, often employed to problems in solid state physics, is that a system may be well described within the confines of the Born-Oppenheimer approximation. As a consequence of the substantial difference of masses, the electrons are assumed to follow the motion of the nuclei adiabatically; hence, the motion of the electrons and nuclei are solved separately. As Jahn and Teller showed in 1936, any non-linear molecule having orbital degeneracy will be unstable to at least one asymmetric displacement which lifts the degeneracy. The wave equation must then be solved taking into account coupling between the electronic and nuclear motion. The E x β system, an electronic doublet coupled to a single mode of vibration, is introduced as an elementary example and is used to illustrate features characteristic of Jahn-Teller systems. The E x ε system is discussed in conjunction with work currently being undertaken on CsTi(SO 4 ) 2 .12H 2 O. In this alum, the [Ti(OH 2 ) 6 ] 3 + cation (3d 1 ) is subject to an axial field which acts to leave a doubly degenerate electronic ground term. Spectroscopic and crystallographic data show the salt to undergo a phase transition at 12 K which we associate with a Co-operative Jahn-Teller Effect manifested by the interaction of the Jahn-Teller electrons with the crystal lattice. Also presented are EPR and SQUID data which illustrate how the Jahn-Teller effect leads to quenching of orbital angular momentum and spin-orbit coupling
Directory of Open Access Journals (Sweden)
Juan Ospina
2006-12-01
Full Text Available Hypercomputers compute functions or numbers, or more generally solve problems or carry out tasks, that cannot be computed or solved by a Turing machine. An adaptation of Tien D. Kieu¿s quantum hypercomputational algorithm is carried out for the dynamical algebra su(1, 1 of the Poschl-Teller potentials. The classically incomputable problem that is resolved with this hypercomputational algorithm is Hilbert¿s tenth problem. We indicated that an essential mathematical condition of these algorithms is the existence of infinitedimensional unitary irreducible representations of low dimensional dynamical algebras that allow the construction of coherent states of the Barut-Girardello type. In addition, we presented as a particular case of our hypercomputational algorithm on Poschl-Teller potentials, the hypercomputational algorithm on an infinite square well presented previously by the authors.Los hipercomputadores computan funciones o números, o en general solucionan problemas que no pueden ser computados o solucionados por una máquina de Turing. Se presenta una adaptación del algoritmo cuántico hipercomputacional propuesto por Tien D. Kieu, al álgebra dinámica su(1, 1 realizada en los potenciales Pöschl-Teller. El problema clásicamente incomputable que se resuelve con este algoritmo hipercomputacional es el d´ecimo problema de Hilbert. Se señala que una condición matemática fundamental para estos algoritmos es la existencia de una representación unitaria infinito dimensional irreducible de álgebras de baja dimensión que admitan la construcción de estados coherentes del tipo Barut-Girardello. Adicionalmente se presenta como caso límite del algoritmo propuesto sobre los potenciales Pöschl-Teller, el algoritmo hipercomputacional sobre la caja de potencial infinita construido previamente por los autores.
Gamow's calculation of the neutron star's critical mass revised
International Nuclear Information System (INIS)
Ludwig, Hendrik; Ruffini, Remo
2014-01-01
It has at times been indicated that Landau introduced neutron stars in his classic paper of 1932. This is clearly impossible because the discovery of the neutron by Chadwick was submitted more than one month after Landau's work. Therefore, and according to his calculations, what Landau really did was to study white dwarfs, and the critical mass he obtained clearly matched the value derived by Stoner and later by Chandrasekhar. The birth of the concept of a neutron star is still today unclear. Clearly, in 1934, the work of Baade and Zwicky pointed to neutron stars as originating from supernovae. Oppenheimer in 1939 is also well known to have introduced general relativity (GR) in the study of neutron stars. The aim of this note is to point out that the crucial idea for treating the neutron star has been advanced in Newtonian theory by Gamow. However, this pioneering work was plagued by mistakes. The critical mass he should have obtained was 6.9 M, not the one he declared, namely, 1.5 M. Probably, he was taken to this result by the work of Landau on white dwarfs. We revise Gamow's calculation of the critical mass regarding calculational and conceptual aspects and discuss whether it is justified to consider it the first neutron-star critical mass. We compare Gamow's approach to other early and modern approaches to the problem.
International Nuclear Information System (INIS)
Chiu, Y.
1997-01-01
We use quantum molecular structure and spectroscopic thoughts of various possible vibronic interactions for the position space of two-electron geminal orbitals with Bloch sums. Our geminals have different degeneracy from one-electron molecular orbitals and are different from the momentum space of BCS free electrons. Based on Herzberg-Teller expansions, our consideration of the aspect of the Renner-Teller effect for cyclic boundary crystals (instead of the usual linear molecules) involves first-order vibronic interaction with isotope effects different from the second-order electron-phonon energy of BCS theory, bipolaron theory, etc. Our consideration of the Jahn-Teller effect with equal-minimum double-well potential leads to the intervalent charge transfer between two degenerate vibrationally affected electronic structures. Our considerations of different style vibrations other than the antisymmetric vibration for the nearest neighbor (e.g., displaced oscillator, etc.) may possibly be related to the case of special chemical structures with special doping and special coherence length. Our simple structural illustrations of such different vibronic Renner-Teller, Jahn-Teller effects and intervalent charge transfer (of La 2-x Sr x CuO 4 and YBa 2 Cu 3 O 7-x ) may promote some possible thoughts of quantum chemical structures compared and mixed with the physical treatments of special high-T c superconductors. copyright 1997 The American Physical Society
customer-teller scheduling system for optimizing banks service
African Journals Online (AJOL)
els Bank Teller scheduling system for optimizing a Banks customer service. The model takes into account real time .... tinuous observation by management personnel and thus results in .... relationships in a mathematical model. A mathematical ...
After the Prestige: A Postmodern Analysis of Penn and Teller
Directory of Open Access Journals (Sweden)
Miller, Liz
2015-12-01
Full Text Available By mocking the magic community and revealing the secret behind some of their tricks, Penn and Teller perform a kind of parodic and post-modern “anti-magic.” Penn and Teller display an artful use of rhetoric; in exposing the secrets and shortcomings of conjuring, they are revolutionizing the way people think about both the art of magic and the magic community. Individuals such as Penn and Teller may use parody to subvert the hegemonic interpretations. However, we also know that it is difficult to bring down a system while operating within that system. Thus, this article explores the way Penn and Teller are challenging the metanarrative of the magic community, using several of the duo’s more popular illusions as examples for analysis. Ultimately, this paper should help us gain a better understanding of the way parody can be used to challenge hegemonic conceptions, and the limitations of this type of rhetorical approach.
On the interplay of Jahn-Teller physics and Mott physics in cuprates
International Nuclear Information System (INIS)
Kamimura, H; Ushio, H
2008-01-01
The extended two-story house model which is now called the Kamimura-Suwa (K-S) model has clarified how the interplay of Mott physics and Jahn-Teller physics plays an important role in determining the superconducting as well as metallic state of underdoped cuprates. In this paper it is first pointed out for underdoped cuprates that Mott physics leads to the existence of local antiferromagnetic order constructed from the localized spins while that the anti-Jahn-Teller effect as a central issue of Jahn-Teller physics leads to the existence of two kinds of orbitals parallel and perpendicular to a CuO 2 plane whose states have nearly the same energy. As a result of the interplay of both physics the K-S model has shown that the exchange interactions between the spins of a localized hole and of a carrier hole play an important role in producing the coexistence of superconductivity and antiferromagnetism in underdoped cuprates. The appearance of d-wave superconductivity even in the phonon-involved mechanism is also shown to be due to the interplay of Jahn-Teller physics and Mott Physics. Brief review of these facts as well as the K-S model is given in this paper. More outstanding result in this paper is that the origin of pseudogap in the deeply underdoped regime has been clarified. In this paper it is shown theoretically for the first time that the so-called T* pseudogap observed in ARPES, STM and tunneling experiments below T c in underdoped cuprates corresponds to the real transition of photo-excited electrons from the occupied states in the originally conduction band below the superconducting gap to a free-electron state above the vacuum level. Thus we conclude that the T* pseudogap in the underdoped cuprates which increases with decreasing the hole concentration is not 'pseudo', but a real gap which exists even below T c
International Nuclear Information System (INIS)
Zamolodchikov, A.B.
1987-01-01
A multipoint conformal block of Ramond states of the two-dimensional free scalar field is calculated. This function is related to the free energy of the scalar field on the hyperelliptic Riemann surface under a particular choice of boundary conditions. Being compactified on the circle this field leads to the crossing symmetric correlation functions with a discrete spectrum of scale dimensions. These functions are supposed to describe multipoint spin correlations of the critical Ashkin-Teller model. (orig.)
DEFF Research Database (Denmark)
Aramburu, José Antonio; García-Fernández, Pablo; García Lastra, Juan Maria
2016-01-01
that the anomalous positive g∥ shift (g∥−g0=0.065) measured at T=20 K obeys the superposition of the |3 z2−r2⟩ and |x2−y2⟩ states driven by quantum effects associated with the zero-point motion, a mechanism first put forward by O'Brien for static Jahn–Teller systems and later extended by Ham to the dynamic Jahn...... of the calculated energy barriers for different Jahn–Teller systems allowed us to explain the origin of the compressed geometry observed for CaO:Ni+....
Jordan blocks and Gamow-Jordan eigenfunctions associated to a double pole of the S-matrix
International Nuclear Information System (INIS)
Hernandez, E.; Mondragon, A.; Jauregui, A.
2002-01-01
An accidental degeneracy of resonances gives rise to a double pole in the scattering matrix, a double zero in the Jost function and a Jordan chain of length two of generalized Gamow-Jordan eigenfunctions of the radial Schrodinger equation. The generalized Gamow-Jordan eigenfunctions are basis elements of an expansion in bound and resonant energy eigenfunctions plus a continuum of scattering wave functions ol complex wave number. In this bi orthonormal basis, any operator f (H r (l) which is a regular function of the Hamiltonian is represented by a complex matrix which is diagonal except for a Jordan block of rank two. The occurrence of a double pole in the Green's function, as well as the non-exponential time evolution of the Gamow-Jordan generalized eigenfunctions are associated to the Jordan block in the complex energy representation. (Author)
Jahn-Teller effect versus Hund's rule coupling in C60N-
Wehrli, S.; Sigrist, M.
2007-09-01
We propose variational states for the ground state and the low-energy collective rotator excitations in negatively charged C60N- ions (N=1,…,5) . The approach includes the linear electron-phonon coupling and the Coulomb interaction on the same level. The electron-phonon coupling is treated within the effective mode approximation which yields the linear t1u⊗Hg Jahn-Teller problem whereas the Coulomb interaction gives rise to Hund’s rule coupling for N=2,3,4 . The Hamiltonian has accidental SO(3) symmetry which allows an elegant formulation in terms of angular momenta. Trial states are constructed from coherent states and using projection operators onto angular momentum subspaces which results in good variational states for the complete parameter range. The evaluation of the corresponding energies is to a large extent analytical. We use the approach for a detailed analysis of the competition between Jahn-Teller effect and Hund’s rule coupling, which determines the spin state for N=2,3,4 . We calculate the low-spin-high-spin gap for N=2,3,4 as a function of the Hund’s rule coupling constant J . We find that the experimentally measured gaps suggest a coupling constant in the range J=60-80meV . Using a finite value for J , we recalculate the ground state energies of the C60N- ions and find that the Jahn-Teller energy gain is partly counterbalanced by the Hund’s rule coupling. In particular, the ground state energies for N=2,3,4 are almost equal.
Energy Technology Data Exchange (ETDEWEB)
Kim, Yeong Hun [Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756 (Korea, Republic of); Jeon, Beom-Yong; You, Tae-Soo [Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of); Ok, Kang Min, E-mail: kmok@cau.ac.kr [Department of Chemistry, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756 (Korea, Republic of)
2015-07-15
Graphical abstract: Ball-and-stick representation of YNbTe{sub 2}O{sub 8} composed of polyhedra of SOJT distortive cations, i.e., NbO{sub 6} and TeO{sub 3}, in the ac-plane. - Highlights: • Two novel tellurite and selenite (YNbQ{sub 2}O{sub 8}; Q = Te and Se) are synthesized. • YNbQ{sub 2}O{sub 8} possess both families of second-order Jahn–Teller distortive cations. • The distortive environments and bonding nature are supported by electronic structure calculations. - Abstract: Two novel quaternary mixed metal tellurite and selenite, YNbTe{sub 2}O{sub 8} and YNbSe{sub 2}O{sub 8}, respectively, have been synthesized through standard solid-state reactions using Y{sub 2}O{sub 3}, Nb{sub 2}O{sub 5}, TeO{sub 2} or SeO{sub 2} as reagents. Single crystal X-ray and powder neutron diffraction analyses have been utilized to determine the structures of the reported materials. YNbTe{sub 2}O{sub 8} and YNbSe{sub 2}O{sub 8} are isostructural to each other and crystallize in the monoclinic centrosymmetric space group, C2/m (No. 12). Due to the two families of constituent second-order Jahn–Teller (SOJT) distortive cations, i.e., Nb{sup 5+} and Te{sup 4+}/Se{sup 4+}, local asymmetric environments occur from the three-dimensional frameworks. Intra-octahedral distortions along the local C{sub 4} direction and asymmetric trigonal pyramidal coordination moieties generated by stereoactive lone pairs are observed from the NbO{sub 6} octahedra and TeO{sub 3} (or SeO{sub 3}) polyhedra, respectively. Thermogravimetric analysis, infrared and UV–vis diffuse reflectance spectroscopies, elemental analysis, out-of-center distortions, dipole moment calculations, and electronic structure calculations for the reported materials are presented.
Numerical study of the spin-1 Ashkin-Teller model
International Nuclear Information System (INIS)
Bekhechi, S.; Badehdah, M.; Benyoussef, A.; Ettaki, B.
1998-07-01
Two non perturbative methods by means of the Transfer-Matrix Finite-Size-Scaling (TMFSS) and Monte Carlo (MC) simulations are used to investigate the spin-1 Ashkin-Teller model (A.T.M.). We have obtained rich phase diagrams with first and second order phase transitions with several multicritical points of higher order. Also this model exhibits a new partially ordered phase PO2 which does not exist in the spin-1/2 Ashkin-Teller model (A.T.M.). Finally, the critical behaviour of this model is discussed. (author)
A SURVEY OF AUTOMATED TELLER MACHINE USAGE IN NORTH INDIA
Shweta Sankhwar*1 & Dhirendra Pandey2
2017-01-01
A machine that hand out cash or executes several banking services at a swipe of Automated Teller Machine (ATM) card in it. An ATM is a machine is use to withdraw cash using a debit card issued by a bank to the consumer(s). An ATM card is issued by a financial organization that permits user to access an Automated Teller Machine (ATM) such as to deposit amount, cash withdrawals, to check account information, etc. It is now preferred to cash by a large majority of the urban population in many ci...
Enhancing the Current Automated Teller Machine (ATM) in Nigerian ...
African Journals Online (AJOL)
This is going to be achieved by creating another input device that collects the money into the ATM system, reads its denomination and either saves it or transfers it the required customer ... Keywords: Automated Teller Machine (ATM), Interswitch, Local Area Network (LAN), Wide Area Network (WAN), Telecommunication.
One of My Favorite Assignments: Automated Teller Machine Simulation.
Oberman, Paul S.
2001-01-01
Describes an assignment for an introductory computer science class that requires the student to write a software program that simulates an automated teller machine. Highlights include an algorithm for the assignment; sample file contents; language features used; assignment variations; and discussion points. (LRW)
Optimal capacity of Ashkin-Teller neural networks
International Nuclear Information System (INIS)
Kozleowski, P.; Bolle, D.
2001-01-01
The maximal capacity per number of couplings is calculated for Ashkin-Teller type neural networks using a replica-symmetric Gardner approach. The results are compared with numerical simulations. The best value obtained at κ=0 is α c =2.26±0.01
PREFACE: XXIst International Symposium on the Jahn-Teller Effect 2012
Koizumi, Hiroyasu
2013-04-01
is obtained. A related problem also arises when dealing with the so-called adiabatic-diabatic transformation (ADT) that removes coupling terms between different Born-Oppenheimer electronic states. It is known that an exact ADT does not exist in general, however, digital computers do this impossible task erroneously if we just plug in numbers. The results obtained may be good in practice; however, we need to be aware that such calculations may miss some important details. I asked Professor Mead to write a note on this matter since there is still confusion in the treatment of the ADT. The proper handling on the ADT may be a topic in the next Jahn-Teller symposium. Although more than a quarter of a century has passed since its discovery, the mechanism of cuprate superconductivity is still actively discussed. In the cuprate, the multi-valuedness problem arises when the conduction electrons create spin-vortices and the twisting of the spin basis occurs. Since a number of experiments and theories indicate the presence of spin-vortices in the cuprate, a proper handling of the multi-valuedness arising from the spin-degree-of-freedom will be important. It has been argued that such multi-valuedness induces a vector potential that generates the persistent current. As the papers in this proceedings indicate, the Jahn-Teller effects are ubiquitous in physics and chemistry. The ideas and methodologies developed in this community have very wide applicability. I believe that this community will continue to contribute to the advancement of science in a fundamental way. Hiroyasu Koizumi Tsukuba, February 2013 Conference photograph
Spin and Pseudospin Symmetries with Trigonometric Pöschl-Teller Potential including Tensor Coupling
Directory of Open Access Journals (Sweden)
M. Hamzavi
2013-01-01
Full Text Available We study approximate analytical solutions of the Dirac equation with the trigonometric Pöschl-Teller (tPT potential and a Coulomb-like tensor potential for arbitrary spin-orbit quantum number κ under the presence of exact spin and pseudospin ( p -spin symmetries. The bound state energy eigenvalues and the corresponding two-component wave functions of the Dirac particle are obtained using the parametric generalization of the Nikiforov-Uvarov (NU method. We show that tensor interaction removes degeneracies between spin and pseudospin doublets. The case of nonrelativistic limit is studied too.
Tran, Henry K.; Stanton, John F.; Miller, Terry A.
2018-01-01
The limitations associated with the common practice of fitting a quadratic Hamiltonian to vibronic levels of a Jahn-Teller system have been explored quantitatively. Satisfactory results for the prototypical X∼2E‧ state of Li3 are obtained from fits to both experimental spectral data and to an "artificial" spectrum calculated by a quartic Hamiltonian which accurately reproduces the adiabatic potential obtained from state-of-the-art quantum chemistry calculations. However the values of the Jahn-Teller parameters, stabilization energy, and pseudo-rotation barrier obtained from the quadratic fit differ markedly from those associated with the ab initio potential. Nonetheless the RMS deviations of the fits are not strikingly different. Guidelines are suggested for comparing parameters obtained from fits to experiment to those obtained by direct calculation, but a principal conclusion of this work is that such comparisons must be done with a high degree of caution.
Rotational Parameters from Vibronic Eigenfunctions of Jahn-Teller Active Molecules
Garner, Scott M.; Miller, Terry A.
2017-06-01
The structure in rotational spectra of many free radical molecules is complicated by Jahn-Teller distortions. Understanding the magnitudes of these distortions is vital to determining the equilibrium geometric structure and details of potential energy surfaces predicted from electronic structure calculations. For example, in the recently studied {\\widetilde{A}^2E^{''} } state of the NO_3 radical, the magnitudes of distortions are yet to be well understood as results from experimental spectroscopic studies of its vibrational and rotational structure disagree with results from electronic structure calculations of the potential energy surface. By fitting either vibrationally resolved spectra or vibronic levels determined by a calculated potential energy surface, we obtain vibronic eigenfunctions for the system as linear combinations of basis functions from products of harmonic oscillators and the degenerate components of the electronic state. Using these vibronic eigenfunctions we are able to predict parameters in the rotational Hamiltonian such as the Watson Jahn-Teller distortion term, h_1, and compare with the results from the analysis of rotational experiments.
Origin of Small Barriers in Jahn–Teller Systems
DEFF Research Database (Denmark)
Barriuso, M. T.; Ortiz-Sevilla, B.; Aramburu, J. A.
2013-01-01
. It is quantitatively proven that the elongated geometry observed for NaCl:Ni+ is due to the 3d–4s vibronic admixture, which is slightly larger than the anharmonicity in the eg JT mode that favors a compressed geometry. The existence of these two competing mechanisms explains the low value of B for the model system......Despite its relevance, the microscopic origin of the energy barrier, B, between the compressed and elongated geometries of Jahn–Teller (JT) systems is not well understood yet because of a lack of quantitative data about its various contributions. Seeking to clear up this matter, we have carried out...
Four-dimensional Ashkin-Teller gauge theory
International Nuclear Information System (INIS)
Alcaraz, F.C.; Jacobs, L.
1983-01-01
The authors construct and analyze a lattice field theory of two Z 2 gauge fields which interact in a minimal gauge-invariant fashion. Although the theory presented here, a generalization of the two-dimensional Ashkin-Teller spin system, has no formal continuum limit, it is found that it has an electrodynamicslike phase similar to that observed in general Z/sub N/ theories for N> or =4. This model is probably the simplest generalization of the conventional Z 2 pure gauge theory which has a massless phase separated from the strong- and weak-coupling regions by lines of second-order phase transitions
UDOANYA RAYMOND MANUEL; ANIEKAN OFFIONG
2014-01-01
This paper presents the importance of applying queuing theory to the Automated Teller Machine (ATM) using Monte Carlo Simulation in order to determine, control and manage the level of queuing congestion found within the Automated Teller Machine (ATM) centre in Nigeria and also it contains the empirical data analysis of the queuing systems obtained at the Automated Teller Machine (ATM) located within the Bank premises for a period of three (3) months. Monte Carlo Simulation is applied to th...
Quantum information entropies of the eigenstates for the P(o)schl-Teller-like potential
Institute of Scientific and Technical Information of China (English)
Guo-Hua Sun; M.Avila Aoki; Shi-Hai Dong
2013-01-01
Shannon entropy for lower position and momentum eigenstates of P(o)schl-Teller-like potential is evaluated.Based on the entropy densities demonstrated graphically,we note that the wave through of the position information entropy density ρ(x) moves right when the potential parameter V1 increases and its amplitude decreases.However,its wave through moves left with the increase in the potential parameter |V2|.Concerning the momentum information entropy density p(p),we observe that its amplitude increases with increasing potential parameter V1,but its amplitude decreases with increasing |V2|.The Bialynicki-Birula-Mycielski (BBM) inequality has also been tested for a number of states.Moreover,there exist eigenstates that exhibit squeezing in the momentum information entropy.Finally,we note that position information entropy increases with V1,but decreases with |V2|.However,the variation of momentum information entropy is contrary to that of the position information entropy.
Quantum information entropies of the eigenstates for the Pöschl—Teller-like potential
International Nuclear Information System (INIS)
Sun Guo-Hua; Aoki, M. Avila; Dong Shi-Hai
2013-01-01
Shannon entropy for lower position and momentum eigenstates of Pöschl—Teller-like potential is evaluated. Based on the entropy densities demonstrated graphically, we note that the wave through of the position information entropy density ρ(x) moves right when the potential parameter V 1 increases and its amplitude decreases. However, its wave through moves left with the increase in the potential parameter |V 2 |. Concerning the momentum information entropy density ρ(p), we observe that its amplitude increases with increasing potential parameter V 1 , but its amplitude decreases with increasing |V 2 |. The Bialynicki—Birula—Mycielski (BBM) inequality has also been tested for a number of states. Moreover, there exist eigenstates that exhibit squeezing in the momentum information entropy. Finally, we note that position information entropy increases with V 1 , but decreases with |V 2 |. However, the variation of momentum information entropy is contrary to that of the position information entropy. (general)
Jahn-teller domains and magnetic domains in Mn2FeO4
Kub, J.; Brabers, V.A.M.; Novák, P.; Gemperle, R.; Simsova, J.
2000-01-01
Elastic (Jahn–Teller) domains and magnetic domains in the tetragonal spinel Mn2FeO4 were studied using X-ray double-crystal topography, X-ray diffractometry and the colloid-SEM method. The Jahn–Teller domains of the measured samples are tetragonal with the [0 0 1] c-axis alternating perpendicularly
Jahn Teller effect of cations in water: The cupric ion in water
Energy Technology Data Exchange (ETDEWEB)
Halley, J.W. [Minnesota Univ., Minneapolis, MN (United States). School of Physics and Astronomy; Wang, X.R. [Hong Kong Univ. of Science and Technology, Kowlon (Hong Kong). Dept. of Physics; Curtiss, L.A. [Argonne National Lab., IL (United States)
1993-02-01
We report a molecular dynamics model for the Jahn Teller effect in the solvation shell of a cation in solution in an aqueous liquid. We apply the model to the cupric ion and compare results with results of neutron scattering experiments on copper chlorate solutions. We conclude that the original interpretation of the experiments in terms of a Jan Teller effect may require modification.
What makes an automated teller machine usable by blind users?
Manzke, J M; Egan, D H; Felix, D; Krueger, H
1998-07-01
Fifteen blind and sighted subjects, who featured as a control group for acceptance, were asked for their requirements for automated teller machines (ATMs). Both groups also tested the usability of a partially operational ATM mock-up. This machine was based on an existing cash dispenser, providing natural speech output, different function menus and different key arrangements. Performance and subjective evaluation data of blind and sighted subjects were collected. All blind subjects were able to operate the ATM successfully. The implemented speech output was the main usability factor for them. The different interface designs did not significantly affect performance and subjective evaluation. Nevertheless, design recommendations can be derived from the requirement assessment. The sighted subjects were rather open for design modifications, especially the implementation of speech output. However, there was also a mismatch of the requirements of the two subject groups, mainly concerning the key arrangement.
Jahn-Teller effect in molecular electronics: quantum cellular automata
Tsukerblat, B.; Palii, A.; Clemente-Juan, J. M.; Coronado, E.
2017-05-01
The article summarizes the main results of application of the theory of the Jahn-Teller (JT) and pseudo JT effects to the description of molecular quantum dot cellular automata (QCA), a new paradigm of quantum computing. The following issues are discussed: 1) QCA as a new paradigm of quantum computing, principles and advantages; 2) molecular implementation of QCA; 3) role of the JT effect in charge trapping, encoding of binary information in the quantum cell and non-linear cell-cell response; 4) spin-switching in molecular QCA based on mixed-valence cell; 5) intervalence optical absorption in tetrameric molecular mixed-valence cell through the symmetry assisted approach to the multimode/multilevel JT and pseudo JT problems.
Off-center Jahn-Teller ion: coupled polar and tetragonal deformations
International Nuclear Information System (INIS)
Vikhnin, V.S.; Sochava, L.S.
1979-01-01
Models of the off-center Jahn-Teller ions are considered, i.e. Ni + in SrO and Cu 27 in SrO studied earlier. Models of the off-center Jahn-Teller ion are proposed, in which mutual effect of dipole-active deformations conditioning off-centering and the Jahn-Teller tetragonal deformations takes place. Manifestations of a new type of multipit potential XY 24 of an off-center ion are considered. The Jahn-Teller effect (JTE) is studied for a duplicate in cubic environment, unharmonism of the fourth order being taken into account. In such a model of Exe of JTE, the position and quantity of minima of adiabatic potential are changed as compared with Exe of JTE taking account of unharmonism of the third order or the square Jahn-Teller interaction. While using models of the off-center Jahn-Teller ion which take account of the effect of two tetragonal Jahn-Teller deformations occurring in the Exe problem considering unharmonism of the fourth order produced on dipole-active deformations, it becomes possible to explain the experiment for SrO:Ni +
The Hintermann-Merlini-Baxter-Wu and the infinite-coupling-limit Ashkin-Teller models
Energy Technology Data Exchange (ETDEWEB)
Huang Yuan, E-mail: huangy22@mail.ustc.edu.cn [Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Deng Youjin, E-mail: yjdeng@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Jacobsen, Jesper Lykke, E-mail: jacobsen@lpt.ens.fr [Laboratoire de Physique Theorique, Ecole Normale Superieure, 24 rue Lhomond, 75231 Paris (France); Universite Pierre et Marie Curie, 4 place Jussieu, 75252 Paris (France); Salas, Jesus, E-mail: jsalas@math.uc3m.es [Grupo de Modelizacion, Simulacion Numerica y Matematica Industrial, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganes (Spain); Grupo de Teorias de Campos y Fisica Estadistica, Instituto Gregorio Millan, Universidad Carlos III de Madrid, Unidad asociada al IEM-CSIC, Madrid (Spain)
2013-03-11
We show how the Hintermann-Merlini-Baxter-Wu model (which is a generalization of the well-known Baxter-Wu model to a general Eulerian triangulation) can be mapped onto a particular infinite-coupling-limit of the Ashkin-Teller model. We work out some mappings among these models, also including the standard and mixed Ashkin-Teller models. Finally, we compute the phase diagram of the infinite-coupling-limit Ashkin-Teller model on the square, triangular, hexagonal, and kagome lattices.
Bethe, Oppenheimer, Teller and the Fermi Award: Norris Bradbury Speaks
Energy Technology Data Exchange (ETDEWEB)
Meade, Roger Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-04-28
In 1956 the Enrico Fermi Presidential Award was established to recognize scientists, engineers, and science policymakers who gave unstintingly over their careers to advance energy science and technology. The first recipient was John von Neumann. .1 Among those scientists who were thought eligible for the award were Hans Bethe, J. Robert Oppenheimer, and Edward Teller. In 1959 Norris Bradbury was asked to comment on the relative merits of each these three men, whom he knew well from their affiliation with Los Alamos. Below is a reproduction of the letter Bradbury sent to Dr. Warren C. Johnson of the AEC’s General Advisory Committee(GAC) containing his evaluation of each man. The letter might surprise those not accustomed to Bradbury’s modus operandi of providing very detailed and forthright answers to the AEC. The letter, itself, was found in cache of old microfilm. Whether because of the age of the microfilm or the quality of the filming process, portions of the letter are not legible. Where empty brackets appear, the word or words could not be read or deduced. Words appearing in brackets are guesses that appear, from the image, to be what was written. These guesses, of course, are just that – guesses.
Is talking to an automated teller machine natural and fun?
Chan, F Y; Khalid, H M
Usability and affective issues of using automatic speech recognition technology to interact with an automated teller machine (ATM) are investigated in two experiments. The first uncovered dialogue patterns of ATM users for the purpose of designing the user interface for a simulated speech ATM system. Applying the Wizard-of-Oz methodology, multiple mapping and word spotting techniques, the speech driven ATM accommodates bilingual users of Bahasa Melayu and English. The second experiment evaluates the usability of a hybrid speech ATM, comparing it with a simulated manual ATM. The aim is to investigate how natural and fun can talking to a speech ATM be for these first-time users. Subjects performed the withdrawal and balance enquiry tasks. The ANOVA was performed on the usability and affective data. The results showed significant differences between systems in the ability to complete the tasks as well as in transaction errors. Performance was measured on the time taken by subjects to complete the task and the number of speech recognition errors that occurred. On the basis of user emotions, it can be said that the hybrid speech system enabled pleasurable interaction. Despite the limitations of speech recognition technology, users are set to talk to the ATM when it becomes available for public use.
Kozuch, Sebastian
2015-07-14
The π bond shifting (automerization) by carbon tunneling of cyclopropenyl anions was computationally analyzed by the small curvature tunneling methodology. Similar to other antiaromatic cases, the process is hindered by substituents departing from planarity, since these groups must be realigned along with the π bond shifting. With hydrogens as substituents the tunneling is extremely fast, in a case of both heavy and light atom tunneling. But, with more massive substituents (such as Me and F), and especially with longer groups (such as CN), the tunneling probability is reduced or even virtually canceled. The automerization of triphenylcyclopropyl anion by tunneling was supposed to be impossible due to the high mass of the phenyl groups. However, it was found that the ground state of this species is actually a D3h aromatic triplet, a single-well system that cannot undergo automerization. For this and other systems with π acceptor groups, the superposition of states that generates the second-order Jahn-Teller distortion is diminished, and by Hund's rule, the triplet results in the ground state.
Directory of Open Access Journals (Sweden)
Antomi Saregar
2015-04-01
Full Text Available In this paper, we show that the exact energy eigenvalues and eigenfunctions of the Schrödinger equation for charged particles moving in a certain class of noncentral potentials can be easily calculated analytically in a simple and elegant manner by using Supersymmetric method (SUSYQM. We discuss the Poschl-Teller plus Scarf non-central potential systems. Then, by operating the lowering operator we get the ground state wave function, and the excited state wave functions are obtained by operating raising operator repeatedly. The energy eigenvalue is expressed in the closed form obtained using the shape invariant properties. The results are in exact agreement with other methods. Keyword: supersymmetry, non-central potentials, poschl teller plus scarf.
Comment on "Histories and Horoscopes: The Ethnographer as Fortune-Teller."
Luttrell, Wendy
1998-01-01
Explores the analogy of the researcher as fortune teller and the parallels between research histories and horoscopes and discusses the tension between what the subject is and what he or she is imagined to be by others. (SLD)
The effect of automated teller machines on banks' services in Nigeria
African Journals Online (AJOL)
AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search ... work is to find out the effects of Automated Teller Machines (ATM) on Bank's services. ... used by successful organizations for gaining competitive advantage over others.
Occupational Noise Exposure among Toll Tellers at Toll Plaza in Malaysia
Azmi, Sharifah Nadya Syed; Dawal, Siti Zawiah Md; Ya, Tuan Mohammad Yusoff Shah Tuan; Saidin, Hamidi
2010-10-01
Toll tellers working at toll plaza have potential of exposure to high noise from the vehicles especially for the peak level of sound emitted by the heavy vehicles. However, occupational exposures in this workplace have not been adequately characterized and identified. Occupational noise exposure among toll tellers at toll plaza was assessed using Sound Level Meter, Noise Dosimeter and through questionnaire survey. These data were combined to estimate the work shift exposure level and health impacts to the toll tellers by using statistical analysis. Noise Dosimeter microphone was located at the hearing zone of the toll teller which working inside the toll booth and full-period measurements were collected for each work shift. The measurements were taken at 20 toll booths from 6.00 am to 2.00 pm for 5 days. 71 respondents participated in the survey to identify the symptoms of noise induced hearing loss and other health related problems among toll tellers. Results of this study indicated that occupational noise exposure among toll tellers for Mean Continuous Equivalent Level, Leq was 79.2±1.4 dB(A), Mean Maximum Level, Lmax was 107.8±3.6 dB(A) and Mean Peak Level, Lpeak was 136.6±9.9 dB. The Peak Level reported statistically significantly at 140 dB, the level of TLV recommended by ACGIH. The research findings indicated that the primary risk exposure to toll tellers comes from noise that emitted from heavy vehicles. Most of the toll tellers show symptoms of noise induced hearing loss and annoyed by the sources of noise at the toll plaza.
International Nuclear Information System (INIS)
Solomonik, V.G.; Pogrebnaya, T.P.
2001-01-01
The basic and the first exciting electronic state of the VF 4 , NbF 4 and TaF 4 molecules were studied by the self-consistent field multifunctional method in the approximation of active orbitals full space. The symmetry of these states is defined as 2 E and 2 T 2 at tetrahedron configuration of the nuclei. The energies of electron excitation 2 E → 2 T 2 comprise 11610 (VF 4 ), 13450 (NbF 4 ) and 12560 cm -1 (TaF 4 ). In line to Jahn-Teller theorem the calculations evidenced instability of tetrahedron configuration of the molecules in the orbital-singular electronic states 2 E and 2 T 2 . The properties of the systems of the molecule potential energies were found, in keeping with deformation of tetrahedron configuration of the nuclei along the oscillation coordinates of the e symmetry, active in the Jahn-Teller effect. Equilibrium geometric configuration of the molecules with the lowest energy has a symmetry D 2d as in the basic ( 2 A 1 ), so in the first excited electronic state. The energy of the adiabatic electronic excitation 2 A 1 → 2 B 2 is equal to 8440 (VF 4 ), 9050 (NbF 4 ) and 11920 cm -1 (TaF 4 ). Deviations of molecules equilibrium geometry on the structure of the normal tetrahedron and the energy of Jahn-Teller stabilization E JT grow essentially in the series of the molecules VF 4 → NbF 4 → TaF 4 : E JT =E(T d , 2 E)Epy - E(D 2d , 2 A 1 )=412, 1856, 5970 cm -1 ; E JT =E(T d , 2 T 2 ) - E(D 2d , 2 B 2 )=3584, 6259, 6611 cm -1 . The quadratic force constants, the frequencies of normal oscillations and the intensities in the IR spectra of the VF 4 , NbF 4 and TaF 4 molecules in the basic state were calculated [ru
Quantum friction of pseudorotation in Jahn-Teller system: Passage through conical intersection
Energy Technology Data Exchange (ETDEWEB)
Pae, Kaja, E-mail: kaja.pae@gmail.com; Hizhnyakov, Vladimir [Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411 Tartu (Estonia)
2016-08-14
A theoretical study of the relaxation of an excited impurity center with strong E × e-type Jahn-Teller effect, caused by the emission of phonons to the bulk, is presented. The dependence of the passing the system through the conical intersection of the potential surface on the momentum of the pseudorotation is figured out. An analytical description of the quantum states of the conical intersection (Slonczewski resonances) is given. It is found that for realistic vibronic interactions with phonons, the characteristic time of the energy loss is several tenths of mean periods of phonons, i.e., it is in the picosecond range. It is also found that there is a finite probability of the speeding-up of the pseudorotation of the system at the intermediate stage of relaxation. In particular, this probability increases close to the Slonczewski resonances. During the relaxation, the system may change the direction of the pseudomoment; the probability of such a change also increases near the resonances.
Handoko, Rio
2012-01-01
Sistem antrian yang diterapkan pada PT. Bank Sumut Cabang Utama Medan menerapkan sistem antrian FIFO / FCFS (First Come First Serve. Pada PT. Bank Sumut Cabang Utama Medan terdapat sepuluh teller atau server yang bertugas melayani pelanggan. Setiap pelanggan yang datang wajib mengambil nomor antrian kemudian menunggu untuk dipanggil oleh teller yang kosong dan kemudian melakukan transaksi. Teller yang telah selesai melayani satu pelanggan kemudian menekan tombol agar antrian berikutnya dapat ...
Crowell, C R; Anderson, D C; Abel, D M; Sergio, J P
1988-01-01
Customer service for bank tellers was defined in terms of 11 verbal behavior categories. An audio-recording system was used to track the occurrence of behaviors in these categories for six retail banking tellers. Three behavior management interventions (task clarification, performance feedback, and social praise), applied in sequence, were designed to improve overall teller performance with regard to the behavioral categories targeted. Clarification was accomplished by providing clear delineation of the various target categories, with specific examples of the behaviors in each. Feedback entailed presentation of ongoing verbal and visual information regarding teller performance. Praise consisted of verbal recognition of teller performance by branch managers. Results showed that clarification effects emerged quickly, producing an overall increase in desired behaviors of 12% over baseline. Feedback and praise effects occurred more gradually, resulting in overall increases of 6% and 7%, respectively. A suspension of all procedures led to a decline in overall performance, whereas reinstatement of feedback and praise was again accompanied by performance improvement. These findings extend the generality of behavior management applications and help to distinguish between possible antecedent and consequent effects of performance feedback.
Science and Technology Review, July-August 1998: Celebrating Edward Teller at 90
Smart, J.
1998-07-01
On the occasion of Edward Teller's 90th birthday, Science and Technology Review (S&TR) has the pleasure of honoring Lawrence Livermore's co-founder and most influential scientist. Teller is known for his inventive work in physics, his concepts leading to thermonuclear explosions, and his strong stands on such issues as science education, the nation's strategic defense, the needs for science in the future, and sharing scientific information. The articles in this issue also show him, as always, tirelessly moving forward with his new and changing interests.
Energy Technology Data Exchange (ETDEWEB)
Chen, Chang-Yuan, E-mail: yctcccy@163.net [School of Physics and Electronics, Yancheng Teachers University, Yancheng 224051 (China); You, Yuan; Lu, Fa-Lin [School of Physics and Electronics, Yancheng Teachers University, Yancheng 224051 (China); Dong, Shi-Hai, E-mail: dongsh2@yahoo.com [Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Edificio 9, Unidad Profesional Adolfo López Mateos, Mexico D.F. 07738 (Mexico)
2013-06-17
We present the position–momentum uncertainties for the Pöschl–Teller potential. We observe that the Δx decreases with the potential depth λ but increases with quantum number n. Interestingly, we find that the Δp first increases and then decreases with the n. The ΔxΔp first decreases and then increases with the λ, but almost becomes a constant (n+1/2)ℏ for a larger λ. Particularly, there exists a squeezed phenomenon in position x for the lower states. The squeezing in x compensated for by an increase in momentum p, such that ΔxΔp⩾ℏ/2 is still satisfied.
International Nuclear Information System (INIS)
Chen, Chang-Yuan; You, Yuan; Lu, Fa-Lin; Dong, Shi-Hai
2013-01-01
We present the position–momentum uncertainties for the Pöschl–Teller potential. We observe that the Δx decreases with the potential depth λ but increases with quantum number n. Interestingly, we find that the Δp first increases and then decreases with the n. The ΔxΔp first decreases and then increases with the λ, but almost becomes a constant (n+1/2)ℏ for a larger λ. Particularly, there exists a squeezed phenomenon in position x for the lower states. The squeezing in x compensated for by an increase in momentum p, such that ΔxΔp⩾ℏ/2 is still satisfied.
We propose to use the new ISOLDE decay station and the neutron detector VANDLE to measure the $\\beta$-delayed neutron emission of N=82-84 $^{130-132}$Cd isotopes. The large delayed neutron emission probability observed in a previous ISOLDE measurement is indicative of the Gamow-Teller transitions due to the decay of deep core neutrons. Core Gamow-Teller decay has been experimentally proven in the $^{78}$Ni region for the N>50 nuclei using the VANDLE array. The spectroscopic measurement of delayed neutron emission along the cadmium isotopic chain will allow us to track the evolution of the single particle states and the shell gap.
Structure of β-decay strength functions
International Nuclear Information System (INIS)
Naumov, Y.V.; Bykov, A.A.; Izosimov, I.N.
1983-01-01
The experimental and theoretical studies on the structure of the Gamow--Teller β-decay strength functions are reviewed. Also considered are processes such as M1 γ decay of analog states, the emission of delayed protons, neutrons, and α particles, delayed fission, and the (p, n) reaction at proton energies 100--200 MeV. The results of measurements of the strength functions by γ-ray total absorption are analyzed. It is shown that the β + decay of nuclei far from the stability band exhibits a new type of collective charge-exchange excitation: Gamow--Teller resonance with μ/sub tau/ = +1
International Nuclear Information System (INIS)
Santiago-Cruz, C
2016-01-01
In this work a position dependent mass Hamiltonian with the same spectrum of the trigonometric Pöschl-Teller one was constructed by means of the underlying potential algebra. The corresponding wave functions are determined by using the factorization method. A new family of isospectral potentials are constructed by applying a Darboux transformation. An example is presented in order to illustrate the formalism. (paper)
Dirac equation with spin symmetry for the modified Pöschl–Teller ...
Indian Academy of Sciences (India)
effective nuclear shell-model scheme [7–9]. Also, various potentials such as the Morse potential [10–12], Wood–Saxon potential [13], Coulomb and Hartmann potentials [14],. Eckart potential [15,16], Pöschl–Teller potential [17,18] and the harmonic potential [19,20] have been studied within the framework of the spin and ...
Wave-Vector Dependence of the Jahn-Teller Interactions in TmVO4
DEFF Research Database (Denmark)
Kjems, Jørgen; Hayes, W.; Smith, S. H.
1975-01-01
The resonant Jahn-Teller coupling of the B2g acoustic phonon and the Zeeman-split ground doublet in TmVO4 has been studied by inelastic neutron scattering. Tuning of the magnetic field provides a means for investigating the wave-vector dependence of the interactions. We find that the coupling...
Investigating the Human Computer Interaction Problems with Automated Teller Machine Navigation Menus
Curran, Kevin; King, David
2008-01-01
Purpose: The automated teller machine (ATM) has become an integral part of our society. However, using the ATM can often be a frustrating experience as people frequently reinsert cards to conduct multiple transactions. This has led to the research question of whether ATM menus are designed in an optimal manner. This paper aims to address the…
Renner-Teller effects in the photoelectron spectra of CNC, CCN, and HCCN.
Coudert, Laurent H; Gans, Bérenger; Garcia, Gustavo A; Loison, Jean-Christophe
2018-02-07
The line intensity of photoelectron spectra when either the neutral or cationic species display a Renner-Teller coupling is derived and applied to the modeling of the photoelectron spectra of CNC, CCN, and HCCN. The rovibronic energy levels of these three radicals and of their cations are investigated starting from ab initio results. A model treating simultaneously the bending mode and the overall rotation is developed to deal with the quasilinearity problem in CNC + , CCN + , and HCCN and accounts for the large amplitude nature of their bending mode. This model is extended to treat the Renner-Teller coupling in CNC, CCN, and HCCN + . Based on the derived photoelectron line intensity, the photoelectron spectra of all three molecules are calculated and compared to the experimental ones.
International Nuclear Information System (INIS)
Prastyaningrum, I.; Cari, C.; Suparmi, A.
2016-01-01
The approximation analytical solution of Dirac equation for Modified Poschl Teller plus Trigonometric Scarf Potential are investigated numerically in terms of finite Romanovsky Polynomial. The combination of two potentials are substituted into Dirac Equation then the variables are separated into radial and angular parts. The Dirac equation is solved by using Romanovsky Polynomial Method. The equation that can reduce from the second order of differential equation into the differential equation of hypergeometry type by substituted variable method. The energy spectrum is numerically solved using Matlab 2011. Where the increase in the radial quantum number nr and variable of modified Poschl Teller Potential causes the energy to decrease. The radial and the angular part of the wave function also visualized with Matlab 2011. The results show, by the disturbance of a combination between this potential can change the wave function of the radial and angular part. (paper)
Energy Technology Data Exchange (ETDEWEB)
Polinger, V., E-mail: polinv@uw.edu [Department of Physics, University of Washington, Seattle, WA 98195-1560 (United States); Garcia-Fernandez, P. [Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Avenida de los Castros s/n, E-39005 Santander (Spain); Bersuker, I.B. [Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, TX 78712-0165 (United States)
2015-01-15
The local origin of dipolar distortions in ABO{sub 3} perovskite crystals is reexamined by means of a novel approach, the Green's function method augmented by DFT computations. The ferroelectric distortions are shown to be induced by the pseudo Jahn–Teller effect (PJTE). The latter involves vibronic hybridization (admixture) of the ground state to same-spin opposite-parity excited electronic bands. Similar to numerous molecular calculations, the PJT approach provides a deeper insight into the nature of chemical bonding in the octahedral cluster [BO{sub 6}] and, in particular, reveals the local origin of its polar instability. This allows predicting directly which transition ions can create ferroelectricity. In particular, the necessary conditions are established when an ABO{sub 3} perovskite crystal with an electronic d{sup n} configuration of the complex ion [BO{sub 6}] can possess both proper ferroelectric and magnetic properties. Distinguished from the variety of cluster approaches to local properties, the Green's function method includes the influence of the local vibronic-coupling perturbation on the whole crystal via the inter-cell interaction responsible for creation of electronic and vibrational bands. Calculated Green's functions combined with the corresponding numeric estimates for the nine electronic bands, their density of states, and the local adiabatic potential energy surface (APES) confirm the eight-minimum form of this surface and feasibility of the PJT origin of the polar instability in BaTiO{sub 3}. We show also that multicenter long-range dipole–dipole interactions critically depend on the PJTE largely determining the magnitude of the local dipoles. DFT calculations for the bulk crystal and its clusters confirm that the dipolar distortions are of local origin, but become possible only when their influence on (relaxation of) the whole lattice is taken into account. The results are shown to be in full qualitative and
Matrix elements of u and p for the modified Poeschl-Teller potential
International Nuclear Information System (INIS)
Gomez-Camacho, J; Lemus, R; Arias, J M
2004-01-01
Closed analytical expressions in terms of a single sum are obtained for the matrix elements of the momentum and the natural variable u tanh(αx) in the basis of the modified Poeschl-Teller (MPT) bound eigenstates. These matrix elements are first expressed in terms of Franck-Condon factors, which thereafter are substituted for analytic expressions. Expansions of the variables p and u in terms of creation and annihilation operators associated with the MPT bound eigenfunctions are also presented
Automated Biometric Voice-Based Access Control in Automatic Teller Machine (ATM)
Yekini N.A.; Itegboje A.O.; Oyeyinka I.K.; Akinwole A.K.
2012-01-01
An automatic teller machine requires a user to pass an identity test before any transaction can be granted. The current method available for access control in ATM is based on smartcard. Efforts were made to conduct an interview with structured questions among the ATM users and the result proofed that a lot of problems was associated with ATM smartcard for access control. Among the problems are; it is very difficult to prevent another person from attaining and using a legitimate persons card, ...
Energy Technology Data Exchange (ETDEWEB)
Libby, S B
2010-12-29
Much has been written about Edward TEller, but little of it is objective. Given, on the one hand, his position as one of the most inventive theoretical physicists of the 20th century, and on the other, his central role in the development and advocacy of thermonuclear weapons, one might imagine it impossible at this point in history to write a scholarly, impartial account of Teller's life and his impact. Now, however, Istvan Hargittai, a prominent Hungarian physical chemist and historian of science, has written a balanced, thoughtful, and beautifully research biography that comes closest. Hargittai is uniquely qualified for this difficult task. Coming a generation and a half later from a similar Hungarian-Jewish background, Hargittai understands well the influences and terrible events that shaped Teller. The advent of virulent, political anti-Semitism, first in Hungary and then in Germany, made Teller twice a refugee. Both Teller and Hargittai lost close family in the Holocaust; Hargittai was himself liberated from a Nazi concentration camp as a child. While Teller was in the US by then, his and Hargittai's surviving family members in Hungary suffered mistreatment at the hands of the postwar Hungarian Communist dictatorship. Hargittai's informed Eastern European perspective also provides a fresh viewpoint to the cold war context of the second half of Teller's career. Furthermore, Hargittai's own scientific work in molecular structure clearly makes him appreciate of Teller's breakthroughs in that field in the 1930s.
Sanz-Ortiz, M. N.; Rodríguez, F.; Baranov, A.; Demazeau, G.
2008-07-01
The objective is to explore through optical spectroscopy and magnetic measurements the coordination and electronic structures of transition-metal ions introduced as impurities with unusual valence states in the oxide perovskite LaAlO3. The selected transition-metal ions Ni3+(3d7) and Co3+(3d6) are characterized by an electronic configuration likely leading to an orbital degenerate E state in Oh symmetry, and thus electron-lattice coupling due to the Jahn-Teller effect may induce low symmetry distortion around the impurity oxygen octahedron. We show that a sol-gel process followed by high oxygen pressure treatments yields stabilization of trivalent state in oxide perovskite. Information about the coordination, electronic structure and aggregation around the magnetic impurity was obtained from X-ray diffraction, FTIR and optical spectroscopy. Finally, evidence on the possible existence of intermediate spin state in Co3+ is under consideration.
International Nuclear Information System (INIS)
Sanz-Ortiz, M N; RodrIguez, F; Baranov, A; Demazeau, G
2008-01-01
The objective is to explore through optical spectroscopy and magnetic measurements the coordination and electronic structures of transition-metal ions introduced as impurities with unusual valence states in the oxide perovskite LaAlO 3 . The selected transition-metal ions Ni 3+ (3d 7 ) and Co 3+ (3d 6 ) are characterized by an electronic configuration likely leading to an orbital degenerate E state in Oh symmetry, and thus electron-lattice coupling due to the Jahn-Teller effect may induce low symmetry distortion around the impurity oxygen octahedron. We show that a sol-gel process followed by high oxygen pressure treatments yields stabilization of trivalent state in oxide perovskite. Information about the coordination, electronic structure and aggregation around the magnetic impurity was obtained from X-ray diffraction, FTIR and optical spectroscopy. Finally, evidence on the possible existence of intermediate spin state in Co 3+ is under consideration
Gali, Adam; Thiering, Gergő
Dopants in solids are promising candidates for implementations of quantum bits for quantum computing. In particular, the high-spin negatively charged nitrogen-vacancy defect (NV) in diamond has become a leading contender in solid-state quantum information processing. The initialization and readout of the spin is based on the spin-selective decay of the photo-excited electron to the ground state which is mediated by spin-orbit coupling between excited states states and phonons. Generally, the spin-orbit coupling plays a crucial role in the optical spinpolarization and readout of NV quantum bit (qubit) and alike. Strong electron-phonon coupling in dynamic Jahn-Teller (DJT) systems can substantially influence the effective strength of spin-orbit coupling. Here we show by ab initio supercell density functional theory (DFT) calculations that the intrinsic spin-orbit coupling is strongly damped by DJT effect in the triplet excited state that has a consequence on the rate of non-radiative decay. This theory is applied to the ground state of silicon-vacancy (SiV) and germanium-vacancy (GeV) centers in their negatively charged state that can also act like qubits. We show that the intrinsic spin-orbit coupling in SiV and GeV centers is in the 100 GHz region, in contrast to the NV center of 10 GHz region. Our results provide deep insight in the nature of SiV and GeV qubits in diamond. EU FP7 DIADEMS project (Contract No. 611143).
Peters, William K.; Tiwari, Vivek; Jonas, David M.
2017-11-01
The nonadiabatic states and dynamics are investigated for a linear vibronic coupling Hamiltonian with a static electronic splitting and weak off-diagonal Jahn-Teller coupling through a single vibration with a vibrational-electronic resonance. With a transformation of the electronic basis, this Hamiltonian is also applicable to the anti-correlated vibration in a symmetric homodimer with marginally strong constant off-diagonal coupling, where the non-adiabatic states and dynamics model electronic excitation energy transfer or self-exchange electron transfer. For parameters modeling a free-base naphthalocyanine, the nonadiabatic couplings are deeply quantum mechanical and depend on wavepacket width; scalar couplings are as important as the derivative couplings that are usually interpreted to depend on vibrational velocity in semiclassical curve crossing or surface hopping theories. A colored visualization scheme that fully characterizes the non-adiabatic states using the exact factorization is developed. The nonadiabatic states in this nested funnel have nodeless vibrational factors with strongly avoided zeroes in their vibrational probability densities. Vibronic dynamics are visualized through the vibrational coordinate dependent density of the time-dependent dipole moment in free induction decay. Vibrational motion is amplified by the nonadiabatic couplings, with asymmetric and anisotropic motions that depend upon the excitation polarization in the molecular frame and can be reversed by a change in polarization. This generates a vibrational quantum beat anisotropy in excess of 2/5. The amplitude of vibrational motion can be larger than that on the uncoupled potentials, and the electronic population transfer is maximized within one vibrational period. Most of these dynamics are missed by the adiabatic approximation, and some electronic and vibrational motions are completely suppressed by the Condon approximation of a coordinate-independent transition dipole between
DEFF Research Database (Denmark)
Aramburu, J. A.; Garcia-Fernandez, P.; García Lastra, Juan Maria
2017-01-01
The applicability of the Jahn-Teller (JT) framework to 6-fold coordinated d9 ions whose local symmetry is not strictly octahedral is explored by means of first principle calculations. Our results contradict much of the existing literature where these systems are analyzed within the quasi-JT regime...... transitions for CuF64- units formed in Cu2+-doped the tetragonal Ba2ZnF6 host lattice. While the experimental d-d transitions cannot be reproduced through the isolated CuF64- unit at the equilibrium geometry, a reasonable agreement is reached adding in the calculation the internal electric field, ER...... state with the hole in the a1g(∼ 3z2-r2) level while it is always placed in the b1g(∼ x2-y2) level for MX6 complexes (M = Cu2+, Ag2+, NiΤ; X = F--, Cl-) in cubic lattices displaying a static JT effect. While the experimental results of CuF64- in Ba2ZnF6 cannot be understood within the JT framework...
Nuclear structure information from nucleon-nucleus scattering experiments at TRIUMF
International Nuclear Information System (INIS)
Haeusser, O.
1989-02-01
We discuss a variety of forward-angle measurements of cross sections for (n,p), (p,p') and (p,n) reactions which were carried out using the medium-resolution spectrometer (MRS) at TRIUMF. The ratio of L=0 isovector spinflip cross section and Gamow-Teller strength has been investigated at 200-450 MeV for several strong transitions of known B(GT) in p-shell nuclei. Isospin symmetry in N-nucleus reactions has been tested for Gamow-Teller transitions to isospin triads in A=6 and A=12 nuclei. The prospects of identifying orbital and meson exchange current contributions in M1 transitions from a state-by-state comparison of M1 and Gamow-Teller strength in sd shell nuclei are discussed. Finally we describe a test of the Gamow-Teller sum rule in 54 Fe where both S - and S + strength are substantial and have been extracted from a multipole decomposition of (p,n) and (n,p) angular distributions
Effect of Jahn-Teller distortion on the short range magnetic order in copper ferrite
Energy Technology Data Exchange (ETDEWEB)
Abdellatif, M.H., E-mail: Mohamed.abdellatif@iit.it [Nanostrctures Department, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy); Innocenti, Claudia [INSTM—Department of Chemistry, University of Florence, via della Lastruccia 3, I-50019 Sesto Fiorentino, FI (Italy); Liakos, Ioannis [Nanostrctures Department, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy); Scarpellini, Alice; Marras, Sergio [Nanochemistry Department, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy); Salerno, Marco [Nanostrctures Department, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy)
2017-02-15
Copper ferrite of spinel crystal structure was synthesized in the form of nano-particles using citrate-gel auto-combustion method. The sample morphology and composition were identified using scanning electron microscopy, X-ray diffraction, and X-ray spectroscopy. The latter technique reveals an inverse spinel structure with Jahn-Teller tetragonal distortion. The static magnetization was measured using vibrating sample magnetometer. Magnetic force microscopy was used in combination with the magnetization data to demonstrate the finite size effect of the magnetic spins and their casting behavior due to the introduction of copper ions in the tetrahedral magnetic sub-lattices, which results in tetragonal distorting the spinel structure of the copper ferrite. The magnetic properties of materials are a result of the collective behavior of the magnetic spins, and magnetic force microscopy can probe the collective behavior of the magnetic spins in copper ferrite, yet providing a sufficient resolution to map the effects below the micrometer size scale, such as the magnetic spin canting. A theoretical study was done to clarify the finite size effect of Jahn-Teller distortion on the magnetic properties of the material. When the particles are in the nano-scale, below the single domain size, their magnetic properties are very sensitive to their size change. - Highlights: • The spin canting due to Jahn-Teller distortion in Copper ferrite can be detected using magnetic force microscope. • The contrast in the magnetic AFM image can be analyzed to give information not only about the surface spins but also about the canting of the core spins inside the aggregated cluster of magnetic nanoparticle.
Experimental confirmation of the Jahn-Teller distortion of CH4+
International Nuclear Information System (INIS)
Gemmell, D.S.; Kanter, E.P.; Pietsch, W.J.
1979-01-01
Measured energy and angular distributions are reported for H + and C/sup n+/ (n = 2,3,4) fragments resulting from the collisional dissociation of 200-keV/amu CH/sub m/ + (m = 0 to 4) in thin carbon targets. From the systematic trends of these Coulomb explosion spectra, qualitative information can be obtained on the structures of these species. In particular, the series displays a narrowing of the carbon angular and energy widths as protons are symmetrically added around a central carbon atom and provide a focusing effect. Because of the Jahn-Teller distortion, the carbon width in CH 4 + is dramatically increased. 8 references
Héraud, Jean-Loup; Lautesse, Philippe; Ferlin, Fabrice; Chabot, Hugues
2017-05-01
Our work extends a previous study of epistemological presuppositions in teaching quantum physics in upper scientific secondary school in France. Here, the problematic reference of quantum theory's concepts is treated at the ontological level (the counterintuitive nature of quantum objects). We consider the approach of using narratives describing possible alternative worlds to address the issue. These possible worlds are based on the counterfactual logic developed in the work of D. Lewis. We will show that the narratives written by G. Gamow describe such possible worlds. Some parts of these narratives are found in textbooks in France. These worlds are governed by laws similar to but importantly different from those in our real world. They allow us to materialize properties inaccessible to everyday experience. In this sense, these fiction stories make ontological propositions concerning the nature and structure of the fundamental elements of our physical universe.
Seifert, A M; Messing, K; Dumais, L
1997-01-01
Work activity and health symptoms of bank tellers whose work was undergoing reorganization were examined during a university-union study of the health effects of work in women's traditional jobs. Data were gathered through collective and individual interviews, analysis of work activity, and a questionnaire administered to 305 tellers. Employees worked in a standing posture over 80 percent of the time. More than two-thirds frequently suffered pain in back, legs, and feet. The average teller had been involved in 3.7 robberies as a direct victim and six as a witness. Work required feats of memory and concentration. In order to meet job demands, tellers engaged in supportive activities and teamwork. The introduction of individualized objectives threatened the employees' ability to collaborate and induced distress. More than twice as many tellers as other female workers in Québec experience psychological distress (Ilfeld scale), related to: robbery during the past two years (odds ratio = 1.7; confidence interval = 1.0-2.9); difficult relations with superiors (O.R. = 2.6; C.I. = 1.3-5.3); and full-time work (O.R. = 2.3; C.I. = 1.3-3.9). Diverse methods enriched the analysis, and union participation allowed the proposal of concrete correction measures.
Ahmad, Nabihah; Rifen, A. Aminurdin M.; Helmy Abd Wahab, Mohd
2016-11-01
Automated Teller Machine (ATM) is an electronic banking outlet that allows bank customers to complete a banking transactions without the aid of any bank official or teller. Several problems are associated with the use of ATM card such card cloning, card damaging, card expiring, cast skimming, cost of issuance and maintenance and accessing customer account by third parties. The aim of this project is to give a freedom to the user by changing the card to biometric security system to access the bank account using Advanced Encryption Standard (AES) algorithm. The project is implemented using Field Programmable Gate Array (FPGA) DE2-115 board with Cyclone IV device, fingerprint scanner, and Multi-Touch Liquid Crystal Display (LCD) Second Edition (MTL2) using Very High Speed Integrated Circuit Hardware (VHSIC) Description Language (VHDL). This project used 128-bits AES for recommend the device with the throughput around 19.016Gbps and utilized around 520 slices. This design offers a secure banking transaction with a low rea and high performance and very suited for restricted space environments for small amounts of RAM or ROM where either encryption or decryption is performed.
Sadhasivam, Jayakumar; Alamelu, M.; Radhika, R.; Ramya, S.; Dharani, K.; Jayavel, Senthil
2017-11-01
Now a days the people's attraction towards Automated Teller Machine(ATM) has been increasing even in rural areas. As of now the security provided by all the bank is ATM pin number. Hackers know the way to easily identify the pin number and withdraw money if they haven stolen the ATM card. Also, the Automated Teller Machine is broken and the money is stolen. To overcome these disadvantages, we propose an approach “Automated Secure Tracking System” to secure and tracking the changes in ATM. In this approach, while creating the bank account, the bank should scan the iris known (a part or movement of our eye) and fingerprint of the customer. The scanning can be done with the position of the eye movements and fingerprints identified with the shortest measurements. When the card is swiped then ATM should request the pin, scan the iris and recognize the fingerprint and then allow the customer to withdraw money. If somebody tries to break the ATM an alert message is given to the nearby police station and the ATM shutter is automatically closed. This helps in avoiding the hackers who withdraw money by stealing the ATM card and also helps the government in identifying the criminals easily.
On the relation between Jahn-Teller ordering and charge ordering
International Nuclear Information System (INIS)
Eijndhoven, J.C.M van.
1978-01-01
This thesis compares the structures of KCusup(II)F 3 and Cs 2 Ausup(I)Ausup(III)Cl 6 . Both compounds have a structure that can be thought to result from a deformation of the cubic perovskite structure. The deformation of KCusup(II)F 3 is a result of a cooperative Jahn-Teller effect and the deformation of Cs 2 Ausup(I)Ausup(III)Cl 6 results in two sublattices. The structures of both compounds result from a continuous phase transition from the cubic pervskite structure due to a deformation of symmetry. Using local coordinates and a calculation of the electron-lattice interaction in a static approximation, four structure types were derived. One is the structure of Cs 2 AuAuCl 6 at ambient temperature and pressure and the second contains a group of structures corresponding to the structures found for KCuF 3 . The third structure type was recently suggested for Cs 2 AuAuCl 6 under pressure and the fourth has not been found experimentally. Two types show a Jahn-Teller ordering and the other two charge ordering (Auth./C.F.)
International Nuclear Information System (INIS)
Natadze, A.L.; Ryskin, A.I.
1980-01-01
The Jahn-Teller (JT) interaction energy is calculated for 5 T 2 and 5 E states of the Cr 2+ ion in ZnS, ZnSe, and ZnTe crystals. The calculations are made within the framework of a particular microscopic model of the crystal field in the distorted crystal (model of point-like exchange charges), the multimode interaction is taken into account. For the 5 T 2 term the energies of interaction with tetragonal and trigonal modes are of the same order of magnitude. This circumstance results in a small height of the barriers that separate various minima of the adiabatic potential and is responsible for the dynamic aspect of the static JT effect in these systems. (author)
Analysis of the workload of bank tellers of a Brazilian public institution.
Serikawa, Simoni S; Albieri, Ana Carolina S; Bonugli, Gustavo P; Greghi, Marina F
2012-01-01
During the last decades there have been many changes in the banking sector organization. It has been also observed the mutual growing of musculoskeletal and mental disorders. This study investigated the workload of bank tellers at a Brazilian public institution. It was performed the Ergonomic Work Analysis (EWA). Three employees participated in this study. During the analysis process, three research instruments were applied: Inventory of Work and Risk of Illness, Yoshitake Fatigue Questionnaire and Nordic Musculoskeletal Questionnaire, beyond the realization of footage recordings and the self-confrontation. The results indicated the existence of an excess of workload on the evaluated workstations, mainly in relation to mental order constraints, that overlaps the physical aspects. Thereby it was found that the employees tend to adopt strategies trying to reduce the impacts of the excess of workload, in order to regulate it.
The effect of band Jahn-Teller distortion on the magnetoresistivity of manganites: a model study
International Nuclear Information System (INIS)
Rout, G C; Panda, Saswati; Behera, S N
2011-01-01
We present a model study of magnetoresistance through the interplay of magnetisation, structural distortion and external magnetic field for the manganite systems. The manganite system is described by the Hamiltonian which consists of the s-d type double exchange interaction, Heisenberg spin-spin interaction among the core electrons, and the static and dynamic band Jahn-Teller (JT) interaction in the e g band. The relaxation time of the e g electron is found from the imaginary part of the Green's function using the total Hamiltonian consisting of the interactions due to the electron and phonon. The calculated resistivity exhibits a peak in the pure JT distorted insulating phase separating the low temperature metallic ferromagnetic phase and the high temperature paramagnetic phase. The resistivity is suppressed with the increase of the external magnetic field. The e g electron band splitting and its effect on magnetoresistivity is reported here. (paper)
The effect of band Jahn-Teller distortion on the magnetoresistivity of manganites: a model study
Energy Technology Data Exchange (ETDEWEB)
Rout, G C [Condensed Matter Physics Group, P G Department of Applied Physics and Ballistics, F M University, Balasore 756 019 (India); Panda, Saswati [Trident Academy of Technology, F2/A, Chandaka Industrial Estate, Bhubaneswar 751 024 (India); Behera, S N, E-mail: gcr@iopb.res.in, E-mail: saswatip7@gmail.com [National Institute of Science and Technology, Palur Hills, Berhampur 761 008 (India)
2011-10-05
We present a model study of magnetoresistance through the interplay of magnetisation, structural distortion and external magnetic field for the manganite systems. The manganite system is described by the Hamiltonian which consists of the s-d type double exchange interaction, Heisenberg spin-spin interaction among the core electrons, and the static and dynamic band Jahn-Teller (JT) interaction in the e{sub g} band. The relaxation time of the e{sub g} electron is found from the imaginary part of the Green's function using the total Hamiltonian consisting of the interactions due to the electron and phonon. The calculated resistivity exhibits a peak in the pure JT distorted insulating phase separating the low temperature metallic ferromagnetic phase and the high temperature paramagnetic phase. The resistivity is suppressed with the increase of the external magnetic field. The e{sub g} electron band splitting and its effect on magnetoresistivity is reported here. (paper)
IMPACT OF NEW GAMOW–TELLER STRENGTHS ON EXPLOSIVE TYPE IA SUPERNOVA NUCLEOSYNTHESIS
Energy Technology Data Exchange (ETDEWEB)
Mori, Kanji; Famiano, Michael A.; Kajino, Toshitaka; Suzuki, Toshio [National Astronomical Observatory of Japan 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hidaka, Jun [Mechanical Engineering Department, Meisei University, 2-1-1 Hodokubo, Hino, Tokyo 191-8506 (Japan); Honma, Michio [Center for Mathematical Sciences, University of Aizu, Aizu-Wakamatsu, Fukushima 965-8580 (Japan); Iwamoto, Koichi [Department of Physics, College of Science and Technology, Nihon University, Tokyo 101-8308 (Japan); Nomoto, Ken’ichi [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Otsuka, Takaharu, E-mail: kanji.mori@nao.ac.jp, E-mail: kajino@nao.ac.jp, E-mail: michael.famiano@wmich.edu, E-mail: suzuki@phys.chs.nihon-u.ac.jp, E-mail: jun.hidaka@meisei-u.ac.jp, E-mail: m-honma@u-aizu.ac.jp, E-mail: iwamoto@phys.cst.nihon-u.ac.jp, E-mail: nomoto@astron.s.u-tokyo.ac.jp, E-mail: otsuka@phys.s.u-tokyo.ac.jp [Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
2016-12-20
Recent experimental results have confirmed a possible reduction in the Gamow–Teller (GT{sub +}) strengths of pf-shell nuclei. These proton-rich nuclei are of relevance in the deflagration and explosive burning phases of SNe Ia. While prior GT strengths result in nucleosynthesis predictions with a lower-than-expected electron fraction, a reduction in the GT{sub +} strength can result in a slightly increased electron fraction compared to previous shell model predictions, though the enhancement is not as large as previous enhancements in going from rates computed by Fuller, Fowler, and Newman based on an independent particle model. A shell model parametrization has been developed that more closely matches experimental GT strengths. The resultant electron-capture rates are used in nucleosynthesis calculations for carbon deflagration and explosion phases of SNe Ia, and the final mass fractions are compared to those obtained using more commonly used rates.
Jahn-Teller distortions, cation ordering and octahedral tilting in perovskites
International Nuclear Information System (INIS)
Lufaso, M.W.; Woodward, P.M.
2004-01-01
In transition metal oxides, preferential occupation of specific d orbitals on the transition metal ion can lead to the development of a long-range ordered pattern of occupied orbitals. This phenomenon, referred to as orbital ordering, is usually observed indirectly from the cooperative Jahn-Teller distortions (CJTDs) that result as a consequence of the orbital ordering. This paper examines the interplay between orbital ordering, octahedral tilting and cation ordering in perovskites. Both ternary AMX 3 perovskites containing an active Jahn-Teller (J-T) ion on the octahedral site and quaternary A 2 MM'X 6 perovskites containing a J-T ion on one-half of the octahedral sites have been examined. In AMX 3 perovskites, the tendency is for the occupied 3d 3x 2 -r 2 and 3d 3z 2 -r 2 orbitals to order in the ac plane, as exemplified by the crystal structures of LaMnO 3 and KCuF 3 . This arrangement maintains a favorable coordination environment for the anion sites. In AMX 3 perovskites, octahedral tilting tends to enhance the magnitude of the J-T distortions. In A 2 MM'X 6 perovskites, the tendency is for the occupied 3d 3z 2 -r 2 orbitals to align parallel to the c axis. This pattern maintains a favorable coordination environment about the symmetric M'-cation site. The orbital ordering found in rock-salt ordered A 2 MM'X 6 perovskites is compatible with octahedral rotations about the c axis (Glazer tilt system a 0 a 0 c - ) but appears to be incompatible with GdFeO 3 -type octahedral tilting (tilt system - b + a - ). (orig.)
International Nuclear Information System (INIS)
Dong Shihai; Gonzalez-Cisneros, A.
2008-01-01
A new exact quantization rule simplifies the calculation of the energy levels for the exactly solvable quantum system. In this work we calculate the energy levels of the Schroedinger equation with the hyperbolic potential by this quantization rule. The corresponding eigenfunction is also derived for completeness. The second Poeschl-Teller like potential case is also carried out
van Anholt, Roel G.; Coelho, Leandro C.; Laporte, Gilbert; Vis, Iris F. A.
The purpose of this paper is to introduce, model, and solve a rich multiperiod inventory-routing problem with pickups and deliveries motivated by the replenishment of automated teller machines in the Netherlands. Commodities can be brought to and from the depot, as well as being exchanged among
Van Anholt, Roel G.; Coelho, Leandro C.; Laporte, Gilbert; Vis, Iris F.A.
2016-01-01
The purpose of this paper is to introduce, model, and solve a rich multiperiod inventory-routing problem with pickups and deliveries motivated by the replenishment of automated teller machines in the Netherlands. Commodities can be brought to and from the depot, as well as being exchanged among
Hour-Glass Neural Network Based Daily Money Flow Estimation for Automatic Teller Machines
Karungaru, Stephen; Akashi, Takuya; Nakano, Miyoko; Fukumi, Minoru
Monetary transactions using Automated Teller Machines (ATMs) have become a normal part of our daily lives. At ATMs, one can withdraw, send or debit money and even update passbooks among many other possible functions. ATMs are turning the banking sector into a ubiquitous service. However, while the advantages for the ATM users (financial institution customers) are many, the financial institution side faces an uphill task in management and maintaining the cash flow in the ATMs. On one hand, too much money in a rarely used ATM is wasteful, while on the other, insufficient amounts would adversely affect the customers and may result in a lost business opportunity for the financial institution. Therefore, in this paper, we propose a daily cash flow estimation system using neural networks that enables better daily forecasting of the money required at the ATMs. The neural network used in this work is a five layered hour glass shaped structure that achieves fast learning, even for the time series data for which seasonality and trend feature extraction is difficult. Feature extraction is carried out using the Akamatsu Integral and Differential transforms. This work achieves an average estimation accuracy of 92.6%.
International Nuclear Information System (INIS)
Hakimifard, A.
2010-01-01
The effect of the donor impurity position and the form of confining potential on the binding energy and the photoionization cross-section if a semiconductor quantum well with Poschl-Teller potential is investigated. An analytical expression for the photoionization cross-section is obtained for the case when the polarization vector of light wave is directed along the direction of size quantization. It is shown that the photoionization cross-section has a threshold behavior
Olusegun Folorunso; Oluwafunmilayo Ayobami Ateji; Gabriel Oludare Awe
2010-01-01
This paper uses the Technology Acceptance Model (TAM) as a basis for studying critical factors that affects the acceptability of Automated Teller Machine (ATM) in Nigeria. Questionnaire approach was used with the respondents predominantly between 20-29 years old. Factor analysis was used to test which of the factors are the main factors affecting the adoption of the technology in Nigeria. It was discovered that the major factors affecting people’s intention to accept ATM are the security issu...
Energy Technology Data Exchange (ETDEWEB)
Wykes, M., E-mail: mikewykes@gmail.com; Parambil, R.; Gierschner, J. [Madrid Institute for Advanced Studies, IMDEA Nanoscience, Calle Faraday 9, Campus Cantoblanco, 28049 Madrid (Spain); Beljonne, D. [Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, 7000 Mons (Belgium)
2015-09-21
Here, we present a general approach to treating vibronic coupling in molecular crystals based on atomistic simulations of large clusters. Such clusters comprise model aggregates treated at the quantum chemical level embedded within a realistic environment treated at the molecular mechanics level. As we calculate ground and excited state equilibrium geometries and vibrational modes of model aggregates, our approach is able to capture effects arising from coupling to intermolecular degrees of freedom, absent from existing models relying on geometries and normal modes of single molecules. Using the geometries and vibrational modes of clusters, we are able to simulate the fluorescence spectra of aggregates for which the lowest excited state bears negligible oscillator strength (as is the case, e.g., ideal H-aggregates) by including both Franck-Condon (FC) and Herzberg-Teller (HT) vibronic transitions. The latter terms allow the adiabatic excited state of the cluster to couple with vibrations in a perturbative fashion via derivatives of the transition dipole moment along nuclear coordinates. While vibronic coupling simulations employing FC and HT terms are well established for single-molecules, to our knowledge this is the first time they are applied to molecular aggregates. Here, we apply this approach to the simulation of the low-temperature fluorescence spectrum of para-distyrylbenzene single-crystal H-aggregates and draw comparisons with coarse-grained Frenkel-Holstein approaches previously extensively applied to such systems.
Double ionization of He and Li by ion impact: Final state correlation
Energy Technology Data Exchange (ETDEWEB)
Fiori, Marcelo [Departamento de Fisica, Universidad Nacional de Salta, 4400 Salta (Argentina)], E-mail: marcelorf@inenco.net; Jalbert, Ginette [Instituto de Fisica, Univ. Federal de Rio de Janeiro, Rio de Janeiro (Brazil); Garibotti, C.R. [CONICET and Centro Atomico Bariloche, 8400 Bariloche (Argentina)
2007-10-15
The total cross-sections for atomic double ionization are evaluated with a two-step approximation, by considering that the projectile ionizes successively each electron. Single ionization probabilities are calculated within the continuum distorted-wave with eikonal initial state (CDW-EIS) formalism. The initial and final atomic wave functions are obtained by solving numerically the atomic wave equations with an optimized potential model (OPM). The electron-electron correlation in the final state is investigated following three different approaches: the usual Gamow factor, a modified Gamow factor with an effective charge and a mean value of the electron-electron repulsive Coulomb wave. The calculations are compared with experimental data and good agreement is found for double ionization of He and Li atoms by H{sup +}, He{sup 2+}and Li{sup 3+} impact, at intermediate energies.
Optical detection of magnetic resonance of the F-centre in CaO in its phosphorescent state
International Nuclear Information System (INIS)
Krap, C.J.
1980-01-01
The F-centre in CaO consists of two electrons trapped in an oxygen vacancy. The centre possesses bound excited states, of which the phosphorescent 3 Tsub(1u) state is a Jahn-Teller state. Jahn-Teller systems have been of interest in many investigations. However, detailed experimental studies about the relaxation paths for the Jahn-Teller states are relatively few. The author studies by means of optical detection of magnetic resonance (ODMR) and phosphorescence microwave double resonance (PMDR) techniques the relaxation between the components of the 3 Tsub(1u) state, the magnetic properties of the individual spin-vibronic Jahn-Teller states and the inhomogeneous line broadening in the ODMR and PMDR spectra. (Auth.)
Microbial Community Patterns Associated with Automated Teller Machine Keypads in New York City.
Bik, Holly M; Maritz, Julia M; Luong, Albert; Shin, Hakdong; Dominguez-Bello, Maria Gloria; Carlton, Jane M
2016-01-01
In densely populated urban environments, the distribution of microbes and the drivers of microbial community assemblages are not well understood. In sprawling metropolitan habitats, the "urban microbiome" may represent a mix of human-associated and environmental taxa. Here we carried out a baseline study of automated teller machine (ATM) keypads in New York City (NYC). Our goal was to describe the biodiversity and biogeography of both prokaryotic and eukaryotic microbes in an urban setting while assessing the potential source of microbial assemblages on ATM keypads. Microbial swab samples were collected from three boroughs (Manhattan, Queens, and Brooklyn) during June and July 2014, followed by generation of Illumina MiSeq datasets for bacterial (16S rRNA) and eukaryotic (18S rRNA) marker genes. Downstream analysis was carried out in the QIIME pipeline, in conjunction with neighborhood metadata (ethnicity, population, age groups) from the NYC Open Data portal. Neither the 16S nor 18S rRNA datasets showed any clustering patterns related to geography or neighborhood demographics. Bacterial assemblages on ATM keypads were dominated by taxonomic groups known to be associated with human skin communities ( Actinobacteria , Bacteroides , Firmicutes , and Proteobacteria ), although SourceTracker analysis was unable to identify the source habitat for the majority of taxa. Eukaryotic assemblages were dominated by fungal taxa as well as by a low-diversity protist community containing both free-living and potentially pathogenic taxa ( Toxoplasma , Trichomonas ). Our results suggest that ATM keypads amalgamate microbial assemblages from different sources, including the human microbiome, eukaryotic food species, and potentially novel extremophilic taxa adapted to air or surfaces in the built environment. DNA obtained from ATM keypads may thus provide a record of both human behavior and environmental sources of microbes. IMPORTANCE Automated teller machine (ATM) keypads represent
Antibiogram of bacteria isolated from automated teller machines in Hamadan, West Iran
Directory of Open Access Journals (Sweden)
Mahmoudi, Hassan
2017-02-01
Full Text Available Aim: Bacteria are ubiquitous in the environment. In keeping with the continued expansion of urbanization and the growing population, an increasing number of people use automated banking, i.e. automated teller machines (ATMs. The aim of this study was to investigate the bacterial contamination and its antibiotic sensitivity on computer keyboards located at ATMs in Hamadan province, Iran. Method: Out of 360 ATMs at four locations in Hamadan, 96 were randomly selected for this study. The antibiotic susceptibility pattern of all isolates was determined by the agar disk diffusion method using gentamicin (10 µg, vancomycin (30 µg, trimethoprim/sulfamethoxazole (25 µg, amikacin (30 µg, tobramycin (10 µg, cephalotin (30 µg, norfloxacin (5 µg, and ceftizoxim (30 µg disks. Results: Melli and Saderat Banks had the most frequently contaminated ATMS, with 18 (27.7% and 12 (18.5%, respectively. The most frequently isolated bacteria were in 12 (18.5% ATMs, in in 11 (16.9%, in 6 (9.2%, spp. in 8 (12.3%, spp. in 2 (3.1%, in 6 (9.2%, in 3 (4.6%, and spp. in 5 (7.69% cases. All isolated bacteria were susceptible to gentamicin, cephalotin, tobramycin, amikacin, norfloxacin, and vancomycin. The resistance rate to trimethoprim/sulfamole was 50%. Conclusion: All tested ATM keyboards were contaminated with at least one species of bacteria. Based on these findings, it is recommendable to disinfect the hands after entering one’s own apartment, work area or a hospital, in order to hinder the spread of critical pathogens in the personal environment or in the hospital.
Antibiogram of bacteria isolated from automated teller machines in Hamadan, West Iran
Mahmoudi, Hassan; Arabestani, Mohammad Reza; Alikhani, Mohammad Yousef; Sedighi, Iraj; Kohan, Hamed Farhadi; Molavi, Mohammad
2017-01-01
Aim: Bacteria are ubiquitous in the environment. In keeping with the continued expansion of urbanization and the growing population, an increasing number of people use automated banking, i.e. automated teller machines (ATMs). The aim of this study was to investigate the bacterial contamination and its antibiotic sensitivity on computer keyboards located at ATMs in Hamadan province, Iran. Method: Out of 360 ATMs at four locations in Hamadan, 96 were randomly selected for this study. The antibiotic susceptibility pattern of all isolates was determined by the agar disk diffusion method using gentamicin (10 µg), vancomycin (30 µg), trimethoprim/sulfamethoxazole (25 µg), amikacin (30 µg), tobramycin (10 µg), cephalotin (30 µg), norfloxacin (5 µg), and ceftizoxim (30 µg) disks. Results: Melli and Saderat Banks had the most frequently contaminated ATMS, with 18 (27.7%) and 12 (18.5%), respectively. The most frequently isolated bacteria were Staphylococcus epidermidis in 12 (18.5%) ATMs, Pseudomonas aeruginosa in 12 (18.5%), Bacillus subtilis in 11 (16.9%), Escherichia coli in 6 (9.2%), Klebsiella spp. in 8 (12.3%), Enterobacter spp. in 2 (3.1%), Bacillus cereus in 6 (9.2%), Staphylococcus aureus in 3 (4.6%), and Micrococcaceae spp. in 5 (7.69%) cases. All isolated bacteria were susceptible to gentamicin, cephalotin, tobramycin, amikacin, norfloxacin, and vancomycin. The S. aureus resistance rate to trimethoprim/sulfamethoxazole was 50%. Conclusion: All tested ATM keyboards were contaminated with at least one species of bacteria. Based on these findings, it is recommendable to disinfect the hands after entering one’s own apartment, work area or a hospital, in order to hinder the spread of critical pathogens in the personal environment or in the hospital. PMID:28197394
Nuclear structure calculations in $^{20}$Ne with No-Core Configuration-Interaction model
Konieczka, Maciej; Satuła, Wojciech
2016-01-01
Negative parity states in $^{20}$Ne and Gamow-Teller strength distribution for the ground-state beta-decay of $^{20}$Na are calculated for the very first time using recently developed No-Core Configuration-Interaction model. The approach is based on multi-reference density functional theory involving isospin and angular-momentum projections. Advantages and shortcomings of the method are briefly discussed.
Charge exchange reactions and solar neutrino detection in 81Br
International Nuclear Information System (INIS)
Liu, K.F.; Gabbard, F.
1983-01-01
The feasibility of 81 Br as the detector of the solar neutrino flux hinges upon the knowledge of the Gamow-Teller matrix element from the ground state of 81 Br to the (5/2) - state at 0.457 MeV in 81 Kr. The possibility of obtaining this matrix element is discussed in terms of the (p,n) and ( 3 He, t) charge exchange reactions. .ID CR2009 .PG 98 112
Nuclear properties for astrophysical applications
Energy Technology Data Exchange (ETDEWEB)
Moeller, P.; Nix, J.R. [Los Alamos National Lab., NM (United States); Kratz, K.L. [Mainz Univ. (Germany). Inst. fuer Kernchemie
1994-09-23
We tabulate the ground-state odd-proton and odd-neutron spins, proton and neutron pairing gaps, binding energies, neuton separation energies, quantities related to {beta}-delayed one, two and three neutron emission probabilities, {beta}-decay Q values and half-lives with respect to Gamow-Teller decay, proton separation energies, and {alpha}-decay Q values and half-lives. The starting point of the calculations is a calculation of nuclear ground-states and (information based on the finite-range droplet model and the folded-Yukawa single-particle model published in a previous issue of ATOMIC DATA AND NUCLEAR DATA TABLES. The {beta}-delayed neutron-emission probabilities and Gamow-Teller {beta}-decay rates are obtained from a QRPA model that uses single-particle levels and wave-functions at the calculated nuclear ground-state shape as the starting point.
Energy Technology Data Exchange (ETDEWEB)
Ilkhani, Ali R. [Institute for Theoretical Chemistry, University of Texas at Austin, Austin, TX 78712 (United States); Department of Chemistry, Yazd Branch, Islamic Azad University, Yazd (Iran, Islamic Republic of); Gorinchoy, Natalia N. [Institute of Chemistry, Academy of Sciences of Moldova, Chisinau, Republic of Moldova (Moldova, Republic of); Bersuker, Isaac B., E-mail: bersuker@cm.utexas.edu [Institute for Theoretical Chemistry, University of Texas at Austin, Austin, TX 78712 (United States); Institute of Chemistry, Academy of Sciences of Moldova, Chisinau, Republic of Moldova (Moldova, Republic of)
2015-10-16
Highlights: • The pseudo Jahn–Teller mechanism of puckering of tetracyclic 1,2-diazetes is revealed. • Vibronic constants are extracted from ab initio calculations versus PJTE equations. • Methods of restoring the planar configuration by external perturbations are suggested. - Abstract: The pseudo Jahn–Teller effect (PJTE) is employed to explain the origin of the puckered structures of tetra-heterocyclic 1,2-diazetes, C{sub 2}N{sub 2}E{sub 4}, E = H, F, Cl, Br, and to reveal the conditions of restoration of their planar configuration. The high-symmetry C{sub 2v} planar configuration of all these compounds is unstable with respect to puckering, a{sub 2}-type distortions produced by the PJT coupling between their ground {sup 1}A{sub 1} and excited {sup 1}A{sub 2} electronic states. The PJTE coupling constants are estimated by fitting ab initio calculated energy profiles to the formulas of the vibronic coupling problem (A{sub 1} + A{sub 2}) ⊗ a{sub 2}. The conditions for the restoration of the planar configurations of the C{sub 2}N{sub 2}E{sub 4} cycles were revealed: the PJTE can be quenched by removing the outer two electrons, e.g. by producing a “triple-decker sandwich” structure with two electron acceptors on both sides of the neutral cycle.
An EPR investigation of the dynamic Jahn-Teller effect in SrCl2:y(2 plus) and SrCl2:Sc(2 plus)
Herrington, J. R.; Estle, T. L.; Boatner, L. A.
1972-01-01
EPR spectra have been observed for SrCl2:Y(2+) and SrCl2:Sc(2+) at liquid helium temperatures. At 1.2 K the spectra were dominated by anisotropic hyperfine patterns whose lineshapes and angular dependences were explained using second order solutions of the effective Hamiltonian for an isolated 2Eg state split by large random internal strains. Pronounced asymmetries in some of the strin produced lineshapes for Srcl2:Sc(2+) are shown to result from second order terms in the solution of the effective Hamiltonian. Coexisting with the anisotropic hyperfine patterns are weak nearly isotropic hyperfine patterns with typical lineshapes. Variations in the apparent intensity of lines in these weak hyperfine patterns as functions of the applied magnetic field direction and temperature imply that these lines result from averaging by vibronic relaxation of a portion of the anisotropic pattern. The effective Hamiltonian parameters for SrCl2:La(2+), SrCl2:y(2+), and SrCl2:SC(2+) are analyzed in terms of crystal field theory modified to include a dynamic Jahn-Teller effect.
Directory of Open Access Journals (Sweden)
Olusegun Folorunso
2010-01-01
Full Text Available This paper uses the Technology Acceptance Model (TAM as a basis for studying critical factors that affects the acceptability of Automated Teller Machine (ATM in Nigeria. Questionnaire approach was used with the respondents predominantly between 20-29 years old. Factor analysis was used to test which of the factors are the main factors affecting the adoption of the technology in Nigeria. It was discovered that the major factors affecting people’s intention to accept ATM are the security issues and poor internet connectivity.
International Nuclear Information System (INIS)
Horowitz, C.J.; Macfarlane, M.H.; Serot, B.D.
1988-01-01
In the period covered by this report (April 1, 1987 to March 31, 1988), work focused on five main areas: Relativistic Theories of Nuclear Structure and Saturation; Relativistic Descriptions of Proton-Nucleus Scattering; Multipole Sum Rules and Ground-State Correlations; Gamow-Teller Excitations in Nuclear Charge-Exchange Reactions; Relativistic Many-Body Theory at Finite Temperature and Density. Results and publications in these areas are summarized in this report. 32 refs., 1 fig
Shape effects in the vicinity of the Z=82 line: study of the $\\beta$-decay of $^{182,184,186}$Hg
This proposal is aimed at the study of the $\\beta$-decay of the neutron-deficient $^{182,184,186}$Hg nuclei using the total absorption technique. Recent theoretical results show that, from measurements of the Gamow-Teller strength distribution, the shapes of the ground states of the decaying Hg nuclei can be inferred. This study offers an independent way to study the phenomenon of shape coexistence in a region of particular interest.
International Nuclear Information System (INIS)
Webster, C. H.; Helme, L. M.; Boothroyd, A. T.; McMorrow, D. F.; Wilkins, S. B.; Detlefs, C.; Detlefs, B.; Bewley, R. I.; McKelvy, M. J.
2007-01-01
A synchrotron x-ray diffraction study of the crystallographic structure of PrO 2 in the Jahn-Teller distorted phase is reported. The distortion of the oxygen sublattice, which was previously ambiguous, is shown to be a chiral structure in which neighboring oxygen chains have opposite chiralities. A temperature dependent study of the magnetic excitation spectrum, probed by neutron inelastic scattering, is also reported. Changes in the energies and relative intensities of the crystal field transitions provide an insight into the interplay between the static and dynamic Jahn-Teller effects
Liu, Shasha; Zhao, Xiuming; Li, Yuanzuo; Zhao, Xiaohong; Chen, Maodu
2009-06-01
Density functional theory (DFT) and time-dependent DFT calculations have been performed to investigate the Raman scattering spectra of metal-molecule complex and metal-molecule-metal junction architectures interconnected with 4-aminothiophenol (PATP) molecule. The simulated profiles of normal Raman scattering (NRS) spectra for the two complexes (Ag2-PATP and PATP-Au2) and the two junctions (Ag2-PATP-Au2 and Au2-PATP-Ag2) are similar to each other, but exhibit obviously different Raman intensities. Due to the lager static polarizabilities of the two junctions, which directly influence the ground state chemical enhancement in NRS spectra, the calculated normal Raman intensities of them are stronger than those of two complexes by the factor of 102. We calculate preresonance Raman scattering (RRS) spectra with incident light at 1064 nm, which is much lower than the S1 electronic transition energy of complexes and junctions. Ag2-PATP-Au2 and Au2-PATP-Ag2 junctions yield higher Raman intensities than those of Ag2-PATP and PATP-Au2 complexes, especially for b2 modes. This effect is mainly attributed to charge transfer (CT) between the metal gap and the PAPT molecule which results in the occurrence of CT resonance enhancement. The calculated pre-RRS spectra strongly depend on the electronic transition state produced by new structures. With excitation at 514.5 nm, the calculated pre-RRS spectra of two complexes and two junctions are stronger than those of with excitation at 1064 nm. A charge difference densities methodology has been used to visually describe chemical enhancement mechanism of RRS spectrum. This methodology aims at visualizing intermolecular CT which provides direct evidence of the Herzberg-Teller mechanism.
Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.
2015-01-01
The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 302 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the Kougarok River drainage as well as smaller adjacent drainages in the Bendeleben and Teller quadrangles, Seward Peninsula, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated
2013-09-01
H. Teller , and E. Teller . 1953. Equation of state calculations by fast computing machines . J Chem Phys, 21: 1087-1092. Skahill, B. E. 2012. Practice...of DE-MC sampler burn-in, a hybrid semi- automated approach was implemented, consistent with available guidance regarding practical application of...treatment of jump proposal dimensions that are out of bounds, and a hybrid, heuristic, semi- automated approach for assessing convergence of the DE-MC
International Nuclear Information System (INIS)
Garcia-Munoz, J.L.; Suaaidi, M.; Fontcuberta, J.; Rodriguez-Carvajal, J.
1997-01-01
The insulator-to-metal transition in the manganite La 0.52 Y 0.15 Ca 0.33 MnO 3 (T IM ∼115 K) has been studied by high-resolution neutron powder diffraction. The cell volume contraction at the Curie point is accompanied by a remarkable decrease of the Jahn-Teller distortion in MnO 6 octahedra. The change of the Mn-O bond lengths at T IM is anisotropic and brings about a drop out of the basal-plane collective distortion mode Q 2 , proposed to be the deformation responsible for the band split of e g↑ orbitals. This is consistent with the double-exchange picture, and precludes simple ferromagnetic exchange. copyright 1997 The American Physical Society
Energy Technology Data Exchange (ETDEWEB)
Rout, G.C., E-mail: gcr@iopb.res.i [Condensed Matter Physics Group, Department of Applied Physics and Ballistics, F.M. University, Balasore, Orissa 756019 (India); Parhi, Nilima [Department of Physics, M.P.C. (Autonomous) College, Baripada, Orissa 757001 (India); Behera, S.N. [Institute of Material Science, Bhubaneswar 751004 (India)
2009-08-01
A model calculation is presented in order to study the magneto-resistivity through the interplay between magnetic and structural transitions for the manganite systems. The model consists of an orbitally doubly degenerate conduction band and a periodic array of local moments of the t{sub 2g} electrons. The band electrons interact with the local t{sub 2g} electrons via the s-f hybridization. The phonons interact with the band electrons through static and dynamic band Jahn-Teller (J-T) interaction. The model Hamiltonian including the above terms is solved for the single particle Green's functions and the imaginary part of the self-energy gives the electron relaxation time. Thus the magneto-resistivity (MR) is calculated from the Drude formula. The MR effect is explained near the magnetic and structural transition temperatures.
A study of cooperative Jahn-Teller phase transitions in rare-earth vanadates by linear birefringence
International Nuclear Information System (INIS)
Gehring, G.A.; Harley, R.T.; Macfarlane, R.M.
1980-01-01
Changes in linear birefringence (Δn) associated with the cooperative Jahn-Teller phase transition of DyV04 near 14K as as a function of temperature and magnetic fields, B, between 0.024 and 0.095T have been measured. Theoretical arguments show that Δn is directly proportional to the order parameter of the transition and that B(2) is equivalent to the conjugate ordering field. By extrapolation to zero field the temperature dependence of the order parameter and the susceptibility were obtained. The data are compared with calculations based on a mean-field 'compressible' Ising model. For a reasonable choice of adjustable parameters this classical description gives a good fit to the data close to Tsub(D) consistent with general theoretical arguments and more detailed calculations, but it deviates progressively away from Tsub(D) presumably because of the known importance of short-range interactions in the system. (author)
DEFF Research Database (Denmark)
Berg, Nelly; Hooper, Thomas N.; Liu, Junjie
2013-01-01
The heterobimetallic complex [Cu(II)Mn(III)(L)(2)(py)(4)](ClO(4))·EtOH (1) built using the pro-ligand 2,2'-biphenol (LH(2)), contains a rare example of a Jahn-Teller compressed Mn(III) centre. Dc magnetic susceptibility measurements on 1 reveal a strong antiferromagnetic exchange between the Cu...
Directory of Open Access Journals (Sweden)
S. Suparmi
2016-11-01
Full Text Available Metode Nikivarof Uvarov merupakan metode penyelesaian persamaan diferensial orde dua dengan mengubah persamaan diferensial orde dua yang umum (persamaan Schrodinger menjadi persamaan diferensial tipe hipergeometrik melalui substitusi variabel yang sesuai untuk memperoleh eigen value dan fungsi gelombang bagian sudut. Penelitian ini merupakan studi literatur untuk menyelesaikan persamaan Schrodinger D-dimensi bagian sudut dengan potensial Poschl-Teller Hiperbolik Terdeformasi q plus Rosen Morse Trigonometri Terdeformasi q menggunakan metode Nikiforov-Uvarov (NU. Pada penelitian ini bertujuan untuk mengetahui bagaimana fungsi gelombang bagian sudut persamaan schrodinger D-dimensi untuk potensial Poschl-Teller Hiperbolik Terdeformasi q plus Rosen Morse Trigonometri Terdeformasi q menggunakan metode Nikiforov-Uvarov (NU.Nikivarof Uvarov is a method to solve second order differential equations by changing general second order differential equation to hyper-geometric differential equation type through substituting relevant variable to obtain eigenvalues and the angle of wave function. This is a literature study to solve the D-dimensional Schrodinger equation with a corner section q Deformed Hyperbolic Poschl Teller plus q Deformed Trigonometric Rosen-Morse Potential using Nikiforov-Uvarov (NU. This study aims to determine the way the angle of wave function of D-dimensional Schrodinger equation for q-Deformed Hyperbolic Poschl Teller plus q Deformed Trigonometric Rosen-Morse Potential using Nikiforov-Uvarov (NU.
E x circle epsilon Jahn-Teller anharmonic coupling for an octahedral system
Avram, N M; Kibler, M R
2001-01-01
The coupling between doubly degenerate electronic states and doubly degenerate vibrations is analyzed for an octahedral system on the basis of the introduction of an anharmonic Morse potential for the vibronic part. The vibrations are described by anharmonic coherent states and their linear coupling with the electronic states is considered. The matrix elements of the vibronic interaction are built and the energy levels corresponding to the interaction Hamiltonian are derived.
Directory of Open Access Journals (Sweden)
S. Chahardoli
2015-12-01
Conclusion: Considering the effect of organizational structure and work-related psychosocial stressors on job satisfaction, it can be stated that organizational restructuring to achieve organic structures and paying more attention to psychosocial stressors in the workplace, can play an effective role in the efficiency and productivity of the organization.
Ifland, Benedikt; Hoffmann, Joerg; Kressdorf, Birte; Roddatis, Vladimir; Seibt, Michael; Jooss, Christian
2017-06-01
The effect of correlation effects on photovoltaic energy conversion at manganite/titanite heterojunctions is investigated. As a model system we choose a heterostructure consisting of the small polaron absorber Pr0.66Ca0.34MnO3 (PCMO) epitaxially grown on single-crystalline Nb-doped SrTi0.998Nb0.002O3 (STNO) substrates. The high structural and chemical quality of the interfaces is proved by detailed characterization using high-resolution transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) studies. Spectrally resolved and temperature-dependent photovoltaic measurements show pronounced contributions of both the Jahn-Teller (JT) excitations and the charge transfer (CT) transitions to the photovoltaic effect at different photon energies. A linear temperature dependence of the open-circuit voltage for an excitation in the PCMO manganite is only observed below the charge-ordering temperature, indicating that the diffusion length of the photocarrier exceeds the size of the space charge region. The photovoltaic response is compared to that of a heterojunction of lightly doped Pr0.05Ca0.95MnO3 (CMO)/STNO, where the JT transition is absent. Here, significant contributions of the CT transition to the photovoltaic effect set in below the Neel temperature. We conclude that polaronic correlations and ordering effects are essentials for photovoltaic energy conversion in manganites.
Modulation of Jahn-Teller effect on magnetization and spontaneous electric polarization of CuFeO2
Xiao, Guiling; Xia, Zhengcai; Wei, Meng; Huang, Sha; Shi, Liran; Zhang, Xiaoxing; Wu, Huan; Yang, Feng; Song, Yujie; Ouyang, Zhongwen
2018-03-01
CuFe0.99Mn0.01O2 and CuFe0.99Co0.01O2 single crystal samples are grown by a floating zone technique and their magnetization and spontaneous electric polarization have been investigated. Similarly with pure CuFeO2, an obviously anisotropic magnetization and spontaneous electric polarization were observed in the both doped samples, and their phase transition critical fields and temperatures are directly doping ion dependent. Considering the different d-shell configuration and ionic size between Mn3+, Co3+ and Fe3+ ions, in which the Mn3+ ion with Jahn-Teller (J-T) effect has different distortion on the geometry frustration from both of Fe3+ and Co3+ ion. Since for Mn3+ ion, the orbital splitting results from the low-symmetry J-T distortion in a crystal-field environment leads to a distorted MnO6 octahedron, which different from undistorted FeO6 and CoO6 octahedrons. The strain between distorted and undistorted octahedrons produces different effects on the spin reorientation transition and spontaneous electric polarization. Although the pure CuFeO2 has a very strong and robust frustration, the presence of the strain due to the random distribution of distorted MnO6 octahedron and undistorted CoO6 (FeO6) octahedrons leads to its spin reorientation transitions and spontaneous electric polarization different from CuFeO2.
Directory of Open Access Journals (Sweden)
Christopher Osita Anyaeche
2018-04-01
Full Text Available The improvement in the provision of banking services to customers enhances bank’s performance (profitability and productivity and the amounts of dividend declared to shareholders as well as bank’s competitiveness. One means of fast tracking the service time for bank customers is through the use of self-servicing machines, such as automated teller machine (ATM. Total service cost, expected waiting time in queue, ATM utilization and percentage of customer loss are some of the performance indices that are used to evaluate the service rendered by a bank’s ATM. This study proposes a framework for evaluating the performance of ATM by integrating queuing model and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS methodology. Applicability of the framework was tested using practical data obtained from four banks in Nigeria. It was observed that the average ATM usage in the study area was less than 50%. The TOPSIS results identified Bank A as the best ranked bank. In addition, the results obtained revealed that banks with two ATM were ranked higher than banks with more than two ATM
Directory of Open Access Journals (Sweden)
Alloul H.
2012-03-01
Full Text Available The discovery in 1991 of high temperature superconductivity (SC in A3C60 compounds, where A is an alkali ion, has been rapidly ascribed to a BCS mechanism, in which the pairing is mediated by on ball optical phonon modes. While this has lead to consider that electronic correlations were not important in these compounds, further studies of various AnC60 with n=1, 2, 4 allowed to evidence that their electronic properties cannot be explained by a simple progressive band filling of the C60 six-fold degenerate t1u molecular level. This could only be ascribed to the simultaneous influence of electron correlations and Jahn-Teller Distortions (JTD of the C60 ball, which energetically favour evenly charged C60 molecules. This is underlined by the recent discovery of two expanded fulleride Cs3C60 isomeric phases which are Mott insulators at ambient pressure. Both phases undergo a pressure induced first order Mott transition to SC with a (p, T phase diagram displaying a dome shaped SC, a common situation encountered nowadays in correlated electron systems. NMR experiments allowed us to study the magnetic properties of the Mott phases and to evidence clear deviations from BCS expectations near the Mott transition. So, although SC involves an electron-phonon mechanism, the incidence of electron correlations has an importance on the electronic properties, as had been anticipated from DMFT calculations.
Chan, Chetwyn C H; Wong, Alex W K; Lee, Tatia M C; Chi, Iris
2009-03-01
The goal of this study was to enhance an existing automated teller machine (ATM) human-machine interface in order to accommodate the needs of older adults. Older adults were involved in the design and field test of the modified ATM prototype. The design of the user interface and functionality took the cognitive and physical abilities of older adults into account. The modified ATM system included only "cash withdrawal" and "transfer" functions based on the task demands and needs for services of older adults. One hundred and forty-one older adults (aged 60 or above) participated in the field test by operating modified or existing ATM systems. Those who operated the modified system were found to have significantly higher success rates than those who operated the existing system. The enhancement was most significant among older adults who had lower ATM-related abilities, a lower level of education, and no prior experience of using ATMs. This study demonstrates the usefulness of using a universal design and participatory approach to modify the existing ATM system for use by older adults. However, it also leads to a reduction in functionality of the enhanced system. Future studies should explore ways to develop a universal design ATM system which can satisfy the abilities and needs of all users in the entire population.
Renner-Teller modelling of recent experimental spectra of H{sub 2}S{sup +}
Energy Technology Data Exchange (ETDEWEB)
Duxbury, Geoffrey [Department of Physics, SUPA, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glagow G4 0NG, Scotland (United Kingdom)
2015-01-22
Recently there has been a renewal of interest in the spectroscopy and dynamics of the formation and fragmentation of the hydrogen sulphide ion, including. rotationally resolved spectra of higher vibrational states of the ∼A{sup 2}A{sub 1}−∼X{sup 2}B{sub 1} system than were obtained previously, and a comprehensive imaging study of the photo-fragmentation routes of highly excited H{sub 2}S{sup +}. In collaboration with Ch. Jungen and A. Alijah I have extended our previous l basis approach to the calculation of the effects of orbital angular momentum in H{sub 2}S{sup +} to include the stretch - bender extensions, with the options of using either the K- or l basis. This new code is being used to calculate the complicated orbital angular momentum and spin-orbit coupling effects responsible for the ro-vibronic pattern measured in some of the new experimental results.
Energy Technology Data Exchange (ETDEWEB)
Kemmler-Sack, S; Rother, H J [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie
1979-01-01
The ordered perovskites Ba/sub 2/ZnUO/sub 6/ (cubic, space group Fm3m) and Ba/sub 2/CuUO/sub 6/ (tetragonal, space group I/sub 4//mmm) form solid solutions. For small Cu content the lattice symmetry is cubic, with x>=0.25 an increasing tetragonal distortion (c/a ..sqrt..2 > 1) is observed. From the vibrational spectra and in accordance with the factor group analysis the symmetry of the UO/sub 6/ octahedra is for small Cu content Osub(h) and on the Cu-rich side Dsub(4h). In the region of the lattice vibrations (T/sub 2/ field) the lifting of the degeneracy - due to the Jahn Teller effect of Cu/sup 2 +/ - leads to a band separation, which decreases with sinking copper content. Therefore the Jahn Teller effect is easily noticeable with vibrational spectroscopic methods. In the corresponding series with Wsup(VI) the vibrational spectroscopic investigations lead qualitatively to the same results as in the Usup(VI) system. As further examples the stacking polytypes Ba/sub 2/ZnTeO/sub 6/ and Ba/sub 2/CuTeO/sub 6/ are considered. The vibrational spectra show, that the Jahn Teller effect in this lattice, which is strengthened by partial face-sharing of octahedra, is less pronounced than in the perovskites in which only corner-sharing is present.
International Nuclear Information System (INIS)
1982-06-01
This report presents results of a Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Teller NTMS quadrangle, Alaska. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form. These machine-readable data, as well as quarterly or semiannual program progress reports containing further information on the HSSR program in general, or on the Los Alamos National Laboratory (LANL) portion of the program in particular, are available from DOE's Technical Library at its Grand Junction Area Office. Presented in this data release are location data, field analyses, and laboratory analyses of several different sample media. For the sake of brevity, many field site observations have not been included in this volume; these data are, however, available on the magnetic tape. Appendices A through D describe the sample media and summarize the analytical results for each medium. The data have been subdivided by one of the Los Alamos National Laboratory sorting programs of Zinkl and others (1981a) into groups of stream-sediment, lake-sediment, stream-water, lake-water, and ground-water samples. For each group which contains a sufficient number of observations, statistical tables, tables of raw data, and 1:1,000,000 scale maps of pertinent elements have been included in this report. Also included are maps showing results of multivariate statistical analyses. Information on the field and analytical procedures used by the Los Alamos National Laboratory during sample collection and analysis may be found in any HSSR data release prepared by the Laboratory and will not be included in this report
Fong, Kenneth N K; Chow, Kathy Y Y; Chan, Bianca C H; Lam, Kino C K; Lee, Jeff C K; Li, Teresa H Y; Yan, Elaine W H; Wong, Asta T Y
2010-04-30
This study aimed to examine the usability of a newly designed virtual reality (VR) environment simulating the operation of an automated teller machine (ATM) for assessment and training. Part I involved evaluation of the sensitivity and specificity of a non-immersive VR program simulating an ATM (VR-ATM). Part II consisted of a clinical trial providing baseline and post-intervention outcome assessments. A rehabilitation hospital and university-based teaching facilities were used as the setting. A total of 24 persons in the community with acquired brain injury (ABI)--14 in Part I and 10 in Part II--made up the participants in the study. In Part I, participants were randomized to receive instruction in either an "early" or a "late" VR-ATM program and were assessed using both the VR program and a real ATM. In Part II, participants were assigned in matched pairs to either VR training or computer-assisted instruction (CAI) teaching programs for six 1-hour sessions over a three-week period. Two behavioral checklists based on activity analysis of cash withdrawals and money transfers using a real ATM were used to measure average reaction time, percentage of incorrect responses, level of cues required, and time spent as generated by the VR system; also used was the Neurobehavioral Cognitive Status Examination. The sensitivity of the VR-ATM was 100% for cash withdrawals and 83.3% for money transfers, and the specificity was 83% and 75%, respectively. For cash withdrawals, the average reaction time of the VR group was significantly shorter than that of the CAI group (p = 0.021). We found no significant differences in average reaction time or accuracy between groups for money transfers, although we did note positive improvement for the VR-ATM group. We found the VR-ATM to be usable as a valid assessment and training tool for relearning the use of ATMs prior to real-life practice in persons with ABI.
Directory of Open Access Journals (Sweden)
Ali Reza Ilkhani
Full Text Available 1,2,3-Trioxolene (C2O3H2 is an intermediate in the acetylene ozonolysis reaction which is called primary ozonide intermediate. The symmetry breaking phenomenon were studied in C2O3H2 and six its derivatives then oxygen atoms of the molecule are substituted by sulphur, selenium, tellurium (C2Y3H2 and hydrogen ligands are replaced with fluorine atoms (C2Y3F2. Based on calculation results, all seven C2Y3Z2 considered in the series were puckered from unstable planar configuration with C2v symmetry to a Cs symmetry stable geometry. The vibronic coupling interaction between the 1A1 ground state and the first excited state 1B1 via the (1A1+1B1 ⊗b1 pseudo Jahn-Teller effect problem is the reason of the breaking symmetry phenomenon and un-planarity of the C2Y3 ring in the C2Y3Z2 series.
Energy Technology Data Exchange (ETDEWEB)
Li, Man-Rong; Deng, Zheng; Lapidus, Saul H.; Stephens, Peter W.; Segre, Carlo U.; Croft, Mark; Paria Sena, Robert; Hadermann, Joke; Walker, David; Greenblatt, Martha
2016-10-17
A novel 6H - type hexagonal perovskite Ba 3 (Cr 0.97(1) Te 0.03 (1 ) ) 2 TeO 9 was prepared at high pressure (6 GPa) and temperature ( 1 773 K). Both transmission electron microscopy and synchrotron powder x - ray diffraction data demonstrate that Ba 3 (Cr 0.97(1) Te 0.03(1) ) 2 TeO 9 crystallize s in P6 3 / mmc with face - shared (Cr 0.97(1) Te 0.03(1) )O 6 octahedral pairs interconnected with TeO 6 octahedra via corner - sharing. Structure analysis shows a mixed Cr 2+ /Cr 3+ valence state with ~ 10% Cr 2+ . The existence of Cr 2+ in Ba 3 (Cr 2+ 0.10(1) Cr 3+ 0.87(1) Te 6+ 0.03 ) 2 TeO 9 is further evidenced by x - ray absorption near edge spectr oscopy . Magnetic properties measurements show a paramagnetic response down to 4 K and a small glassy - state curvature at low temperature. In this work, the o ctahedral Cr 2+ O 6 component is stabilized in an oxide material for the first time ; the expected Jahn - Teller distortion of high - spin ( d 4 ) Cr 2+ is not found , which is attributed to the small proportion of Cr 2+ (~ 10%) and the face - sharing arrangement of CrO 6 octahedral pairs, that structu rally dis favor axial distortion.
Directory of Open Access Journals (Sweden)
Li Teresa HY
2010-04-01
Full Text Available Abstract Objective This study aimed to examine the usability of a newly designed virtual reality (VR environment simulating the operation of an automated teller machine (ATM for assessment and training. Design Part I involved evaluation of the sensitivity and specificity of a non-immersive VR program simulating an ATM (VR-ATM. Part II consisted of a clinical trial providing baseline and post-intervention outcome assessments. Setting A rehabilitation hospital and university-based teaching facilities were used as the setting. Participants A total of 24 persons in the community with acquired brain injury (ABI - 14 in Part I and 10 in Part II - made up the participants in the study. Interventions In Part I, participants were randomized to receive instruction in either an "early" or a "late" VR-ATM program and were assessed using both the VR program and a real ATM. In Part II, participants were assigned in matched pairs to either VR training or computer-assisted instruction (CAI teaching programs for six 1-hour sessions over a three-week period. Outcome Measures Two behavioral checklists based on activity analysis of cash withdrawals and money transfers using a real ATM were used to measure average reaction time, percentage of incorrect responses, level of cues required, and time spent as generated by the VR system; also used was the Neurobehavioral Cognitive Status Examination. Results The sensitivity of the VR-ATM was 100% for cash withdrawals and 83.3% for money transfers, and the specificity was 83% and 75%, respectively. For cash withdrawals, the average reaction time of the VR group was significantly shorter than that of the CAI group (p = 0.021. We found no significant differences in average reaction time or accuracy between groups for money transfers, although we did note positive improvement for the VR-ATM group. Conclusion We found the VR-ATM to be usable as a valid assessment and training tool for relearning the use of ATMs prior to real
Kim, Yeong Hun; Lee, Dong Woo; Ok, Kang Min
2013-10-07
Three new quaternary scandium vanadium selenium/tellurium oxides, α-ScVSe2O8, β-ScVSe2O8, and ScVTe2O8 have been synthesized through hydrothermal and standard solid-state reactions. Although all three reported materials are stoichiometrically similar, they exhibit different crystal structures: α-ScVSe2O8 has a three-dimensional framework structure consisting of ScO6, VO6, and SeO3 groups. β-ScVSe2O8 reveals another three-dimensional framework composed of ScO7, VO5, and SeO3 polyhedra. ScVTe2O8 shows a layered structure with ScO6, VO4, and TeO4 polyhedra. Interestingly, the constituent cations, that is, Sc(3+), V(5+), Se(4+), and Te(4+) are all in a distorted coordination environment attributable to second-order Jahn-Teller (SOJT) effects. Complete characterizations including infrared spectroscopy, elemental analyses, thermal analyses, dipole moment calculation, and the magnitudes of out-of-center distortions for the compounds are reported. Transformation reactions suggest that α-ScVSe2O8 may change to β-ScVSe2O8, and then to Sc2(SeO3)3·H2O under hydrothermal conditions.
A statistical calculation of the β- strength function
International Nuclear Information System (INIS)
Arvieu, R.; Haq, R.U.; Touchard, J.
1976-01-01
A microscopic calculation of the Gamow-Teller strength between the 0 + ground state of 208 Pb and the 1 + particle-hole states of 208 Bi assuming the particle-hole matrix elements as random numbers with some specified distribution, is described. Under certain conditions for the two-body matrix elements, a G.T. resonance occurs. The stability of this collective state along with the accompanying low energy β - -strength tail is studied for various samples of p-h matrix elements [fr
International Nuclear Information System (INIS)
Turner, J.E.
1976-07-01
Work leading to the discovery of the minimum dipole moment for electron binding, D/sub min/ = 0.639 ea 0 (atomic units), by several groups in 1967-68 is described. It was subsequently learned that this number had been published in 1947 by Fermi and Teller, who did not, however, indicate how they derived it. The author has found a numerical solution in Fermi's notebooks from 1946-50 at the University of Chicago Library. Fermi's work is described and presented here with relevant material from his notebooks
International Nuclear Information System (INIS)
Turner, J.E.
1977-01-01
Work leading to the discovery of the minimum dipole moment for electron binding, D/sub min/=0.639 ea 0 (atomic units), by several groups in 1967--1968 is described. It was subsequently learned that this number had been published in 1947 by Fermi and Teller, who did not, however, indicate how they derived it. The author has found a numerical solution in Fermi's notebooks from 1946--1950 at the University of Chicago Library. Fermi's work is described and presented here with relevant material from his notebooks
Picconi, David; Grebenshchikov, Sergy Yu.
2018-03-01
This paper opens a series in which the photochemistry of the two lowest πσ* states of pyrrole and their interaction with each other and with the ground electronic state X ˜ are studied using ab initio quantum mechanics. New 24-dimensional potential energy surfaces for the photodissociation of the N-H bond and the formation of the pyrrolyl radical are calculated using the multiconfigurational perturbation theory (CASPT2) for the electronic states X ˜ (π π ) , 11A2(πσ*), and 11B1(πσ*) and locally diabatized. In this paper, the ab initio calculations are described and the photodissociation in the state 11A2(πσ*) is analyzed. The excitation 11 A2←X ˜ is mediated by the coordinate dependent transition dipole moment functions constructed using the Herzberg-Teller expansion. Nuclear dynamics, including 6, 11, and 15 active degrees of freedom, are studied using the multi-configurational time-dependent Hartree method. The focus is on the frequency resolved absorption spectrum as well as on the dissociation time scales and the resonance lifetimes. Calculations are compared with available experimental data. An approximate convolution method is developed and validated, with which absorption spectra can be calculated and assigned in terms of vibrational quantum numbers. The method represents the total absorption spectrum as a convolution of the diffuse spectrum of the detaching H-atom and the Franck-Condon spectrum of the heteroaromatic ring. Convolution calculation requires a minimal quantum chemical input and is a promising tool for studying the πσ* photodissociation in model biochromophores.
History of Giant Resonances and Quenching
Arima, A
1999-01-01
The history of nuclear magnetic moments and Gamow-Teller transitions is reviewed. The importance of configuration mixing and core polarization to explain the quenching phenomena is shown, and discussed in the context of the recent measurement of the Gamow-Teller strength in sup 9 sup 0 Nb. It is confirmed that the contribution of the DELTA-hole excitation to the quenching of spin matrix elements is small.
Energy Technology Data Exchange (ETDEWEB)
Pratik, Saied Md.; Chowdhury, Chandra; Bhattacharjee, Rameswar; Jahiruddin, Sk.; Datta, Ayan, E-mail: spad@iacs.res.in
2015-10-16
Highlights: • DFT calculations show that sulfur rich cyclic molecules are generally distorted. • Such distortions are shown to arise from Pseudo Jahn–Teller (PJT) effects. • Low OMO–UMO gaps leads to strong vibronic instability for these systems. • Increasing the OMO–UMO gaps by substituting electronegative groups on the cyclic rings decreases PJT effects. • Suppressed PJT instability lead to planar sulfur rich cyclic molecules. - Abstract: The tricyclic carbon-sulfide, C{sub 6}S{sub 8} molecule containing two S-atoms in the 1,4-position of the central six-membered ring and one disulfide (S−S) and one thione (C=S) bond on the five membered rings on its either side (1) possesses a “butterfly flapping” type distorted ground state in the gas-phase and also in β-phase of the crystal. For the isolated molecule, better consideration of the S…S non-bonding interactions in the dithiine ring in the bent form at the M06-2X/6-31+G(d,p) level leads to a significant barrier for inversion of 2.4 kcal/mol which is 2–3 times more than that previously obtained by Weber and Dolg at the B3LYP/cc-pVTZ level due to underestimation of dispersion interactions at the B3LYP level. The origin of the distortion leading to lowering of symmetry for 1 (C{sub 2h} → C{sub 2}) is traced to vibronic mixing between the ground state (Ag) and the low lying excited states of A{sub u} symmetry through the a{sub u} normal mode, a (1A{sub g} + 1A{sub u} + 2A{sub u} + 3A{sub u}) × a{sub u} pseudo Jahn–Teller effect (PJTE) problem. Based on fitting of the ground state APES to the lowest root of the 4 × 4 secular determinant, we calculate the linear vibronic coupling constants (F{sub 0i}) between the relevant states. Similar in class to 1, the S-oxygenated derivative of dithiine, C{sub 4}H{sub 4}(SO{sub 2}){sub 2} (2) unlike most other dithiines, remains planar. The absence of the butterfly-type puckered structure in 2 is traced to the enhanced gap (Δ{sub 0}) and very small
International Nuclear Information System (INIS)
Alam, Y.; Suparmi; Cari; Anwar, F.
2016-01-01
In this study, we used asymptotic iteration method (AIM) to obtain the relativistic energy spectra and wavefunctions for D Dimensional Dirac equation. Solution of the D Dimensional Dirac equation using asymptotic iteration method was done by four steps. The first step, we substitutied q deformed Poschl-Teller potential plus q-deformed Manning Rosen Non-Central potential into D dimensional Dirac equation. And then, general term of D dimensioanl Dirac equation for q deformed Poschl-Teller potential plus q-deformed Manning Rosen Non-Central potential was reduced into one dimensioanal Dirac equation, consist of radial part and angular part. The second step, both of one dimensional part must be reduced to hypergeometric type differential equation by suitable parameter change. And then, hypergeometric type differential equation was transformed into AIM type differential equation. For the last step, AIM type differential equation can be solved to obtain the relativistic energy and wavefunctions of Dirac equation. Relativistic energy and wavefunctions were visualized by using Matlab software. (paper)
Landau-Migdal parameters and pion condensation
Energy Technology Data Exchange (ETDEWEB)
Tatsumi, Toshitaka [Department of Physics, Kyoto Univ., Kyoto (Japan)
1999-08-01
The possibility of pion condensation, one of the long-standing issues in nuclear physics, is reexamined in the light of the recent experimental data on the giant Gamow-Teller resonance. The experimental result tells that the coupling of nucleon particle-hole states with {delta} isobar-hole states in the spin-isospin channel should be weaker than that previously believed. It, in turn, implies that nuclear matter has the making of pion condensation at low densities. The possibility and implications of pion condensation in the heavy-ion collisions and neutron stars should be seriously reconsidered. (author)
Beta-decay strength and isospin mixing studies in the sd and fp-shells
International Nuclear Information System (INIS)
Jokinen, A.; Aeystoe, J.; Dendooven, P.; Honkanen, A.; Lipas, P.; Peraejaervi, K.; Oinonen, M.; Siiskonen, T.
1998-01-01
We have studied beta decays of M T 41 Ti shows a large, 10(8) %, isospin mixing of IAS and the Gamow-Teller strength is observed to be quenched by a factor of q 2 =0.64. These results can be reproduced qualitatively in our shell model calculations. We have observed for the first time proton and gamma decay of the isobaric analogue state in 23 Mg. Our results on the isospin mixing of the isobaric analogue state agrees well with the shell model calculations. The obtained proton branch of the IAS is used to extract the transition strength for the reaction 22 Na(p,γ) 23 Mg
International Nuclear Information System (INIS)
Ramdhane, M.; Baumann, P.; Knipper, A.; Walter, G.; Janas, Z.; Plochocki, A.; Liu, W.; Grawe, H.; Hu, Z.; Kirchner, R.; Klepper, O.; Roeckl, E.; Gorska, M.; Fujita, Y.; Brown, B.A.
1998-02-01
By measuring positrons and β-delayed γ-rays emitted from mass-separated sources, the decay of 56 Cu(4 + ,T z =-1,T=1) to states in the doubly-magic nucleus 56 Ni was studied for the first time. The half-life of 56 Cu was measured to be 78(15) ms, and four β-delayed γ-rays were assigned to its decay. The resulting experimental data on Fermi and Gamow-Teller strength are compared with shell-model predictions. (orig.)
Quasielastic nucleon scattering using polarized beams and targets
International Nuclear Information System (INIS)
Haeusser, O.
1990-07-01
Inelastic scattering of polarized intermediate energy nucleons to continuum nuclear states is discussed with emphasis on recent results. Spin momentum correlations of protons in polarized targets of 3 He were observed for the first time. Complete spin observables in (p,p') show effects of the nuclear spin-isospin response and of an NN interaction modified by the nuclear medium. A comparison of Gamow Teller and isovector M1 giant resonance strengths in the sd shell provides evidence for large meson exchange current effects in the M1. (Author) (37 refs., 2 tabs., 9 figs.)
Isovector excitations of N ≠ Z nuclei
International Nuclear Information System (INIS)
Passos, E.J.V. de; Menezes, D.P.; Galeao, A.P.N.R.
1987-09-01
We show that the method based on the tensor coupling of an appropriate family of isovector excitation operators to the parent isospin multiplet can be used, to advantage, for the correct treatment of the isospin degree of freedom in non isoscalar nuclei. This method is applicable to any isovector excitation operator and for parent states which need not to be of the closed subshells type. As an illustration we apply it to the study of the Gamow-Teller transition strength in 90 Zr. (author) [pt
Caballero ontanaya, L; Garcia borge, M J; Malbrunot, S
2002-01-01
This proposal is aimed at the study of the $\\beta$- decay of the neutron-deficient $^{188,190,192}$Pb nuclei. The main motivation of the proposed experiment is to determine the Gamow-Teller strength distribution in the daughter nuclei using the Total Absorption Spectrometer "Lucrecia". Recent theoretical results show that from this measurement the shapes of the ground states of the decaying Pb nuclei can be inferred. This study offers an independent way to study the phenomenon of shape co-existence in a region of particular interest.
Statistical theory for calculating energy spectra of β-delayed neutrons
International Nuclear Information System (INIS)
Kawano, Toshihiko; Moeller, Peter; Wilson, William B.
2008-01-01
Theoretical β-delayed neutron spectra are calculated based on the Quasi-particle Random Phase Approximation (QRPA) and the Hauser-Feshbach statistical model. Neutron emissions from an excited daughter nucleus after β-decay to the granddaughter residual are more accurately calculated than previous evaluations, including all the microscopic nuclear structure information, such as a Gamow-Teller strength distribution and discrete states in the granddaughter. The calculated delayed-neutron spectra reasonably agree with those evaluations in the ENDF decay library, which are based on experimental data. The model was adopted to generate the delayed-neutron spectra for all 271 precursors. (authors)
International Nuclear Information System (INIS)
Trinder, W.; Adelberger, E.G.; Keller, H.; Krumbholz, K.; Rykaczewski, K.
1994-11-01
The β-decay of 37 Ca has been studied. The half-life was remeasured with improved precision to be 181(1) ms, and β-delayed γ-rays were observed for the first time. The surprisingly high Γ γ /Γ p values for proton-unbound states in 37 K drastically reduce former discrepancies between the Gamow-Teller strength values B(GT) measured in the 37 Ga β-decay and those deduced from the 37 Cl(p, n) 37 Ar mirror reaction. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Ramdhane, M.; Baumann, P.; Knipper, A.; Walter, G. [Institute de Recherches Subatomiques, 67 - Strasbourg (France); Janas, Z.; Plochocki, A. [Warsaw Univ. (Poland). Inst. of Experimental Physics; Aeystoe, J.; Dendooven, P.; Jokinen, A.; Oinonen, M.; Pentilae, H. [Jyvaeskylae Univ. (Finland); Liu, W.; Grawe, H.; Hu, Z.; Kirchner, R.; Klepper, O.; Roeckl, E. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Gorska, M. [Warsaw Univ. (Poland). Inst. of Experimental Physics]|[Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Fujita, Y. [Osaka Univ. (Japan); Brown, B.A. [Michigan State Univ., East Lansing, MI (United States)
1998-02-01
By measuring positrons and {beta}-delayed {gamma}-rays emitted from mass-separated sources, the decay of {sup 56}Cu(4{sup +},T{sub z}=-1,T=1) to states in the doubly-magic nucleus {sup 56}Ni was studied for the first time. The half-life of {sup 56}Cu was measured to be 78(15) ms, and four {beta}-delayed {gamma}-rays were assigned to its decay. The resulting experimental data on Fermi and Gamow-Teller strength are compared with shell-model predictions. (orig.)
Marechal, F; Caballero ontanaya, L
2002-01-01
In the framework of the investigation of the shapes of the ground states of the parent nucleus, we propose to carry out measurements of the complete Gamow-Teller strength distribution for the $^{76-80}$Sr isotopes, with a new Total Absorption Gamma Spectrometer installed on a new beam line. The results will be compared with theoretical calculations based on the mean field approach. A brief report on the IS370 experiment on $^{72-75}$Kr decay, which was recently performed at ISOLDE, will be given and the performance of the sum spectrometer will be presented.
Shell-model calculations of beta-decay rates for s- and r-process nucleosyntheses
International Nuclear Information System (INIS)
Takahashi, K.; Mathews, G.J.; Bloom, S.D.
1985-01-01
Examples of large-basis shell-model calculations of Gamow-Teller β-decay properties of specific interest in the astrophysical s- and r- processes are presented. Numerical results are given for: (1) the GT-matrix elements for the excited state decays of the unstable s-process nucleus 99 Tc; and (2) the GT-strength function for the neutron-rich nucleus 130 Cd, which lies on the r-process path. The results are discussed in conjunction with the astrophysics problems. 23 refs., 3 figs
Energy Technology Data Exchange (ETDEWEB)
Courtin, S.; Baumann, P.; Dessagne, Ph.; Marechal, F.; Miehe, Ch.; Perrot, F.; Poirier, E.; Ramdhane, M. [Institut de Recherches Subatomiques, Strasbourg Cedex 2 (France); ISOLDE collaboration
2004-09-15
This paper describes two beta decay experiments performed at the CERN/ISOLDE mass separator. The structure of {sup 74}Kr has been studied using a total absorption {gamma} spectrometer (TAgS). The measured Gamow-Teller strength is presented and compared to HFBCS+QRPA calculations. The {sup 33}Na decay is also presented. The structure of the {sup 33}Mg daughter nucleus is compared to shell-model calculations, showing for the first time an inversion of states in the A{sub {approx}}35 mass region. (author)
An Anomaly in the Inglis-Teller Limits of the C VI Lyman and Balmer Series in Laser-Produced Plasmas
Elton, R.; Iglesias, E.; Griem, H.; Weaver, J.; Pien, G.; Mancini, R.
2002-11-01
Soft x-ray spectra from thin carbon layers heated by the OMEGA and NIKE lasers have been obtained with both spherical and planar targets, respectively, using a flat-field grazing incidence spectrograph equipped with a gated microchannel plate for temporal resolution. In both experiments, late-time (recombining) hydrogenic C VI spectra show an n-to-1 Lyman spectral series blending with the continuum at n=4, contrary to n=9 in the n-to-2 Balmer series. It appears unlikely that plasma inhomogeneities are the sole cause of this anomaly, given the difference in the experimental configurations. Other explanations for the line-to-continuum merging (other than the usual Stark-broadened Inglis-Teller effect) under consideration include non-thermal Doppler broadening, deviations from statistical sublevel population distributions, and opacity effects. Collisional-radiative and hydrodynamic modeling, including cascades, is employed to further understand this phenomenon.
Suparmi, A.; Cari, C.; Pratiwi, B. N.
2016-04-01
D-dimensional Dirac equation of q-deformed modified Poschl-Teller plus Manning Rosen non-central potential was solved using supersymmetric quantum mechanics (SUSY QM). The relativistic energy spectra were analyzed by using SUSY QM and shape invariant properties from radial part of D dimensional Dirac equation and the angular quantum numbers were obtained from angular part of D dimensional Dirac equation. The SUSY operators was used to generate the D dimensional relativistic wave functions both for radial and angular parts. In the non-relativistic limit, the relativistic energy equation was reduced to the non-relativistic energy. In the classical limit, the partition function of vibrational, the specific heat of vibrational, and the mean energy of vibrational of some diatomic molecules were calculated from the equation of non-relativistic energy with the help of error function and Mat-lab 2011.
International Nuclear Information System (INIS)
De Oliveira, Z.M.
1980-01-01
A detailed analysis of the simple statistical model description for delayed neutron emission of 87 Br, 137 I, 85 As and 135 Sb has been performed. In agreement with experimental findings, structure in the #betta#-strength function is required to reproduce the envelope of the neutron spectrum from 87 Br. For 85 As and 135 Sb the model is found incapable of simultaneously reproducing envelopes of delayed neutron spectra and neutron branching ratios to excited states in the final nuclei for any choice of #betta#-strength function. The results indicate that partial widths for neutron emission are not compatible with optical-model transmission coefficients. The simple shell model with pairing is shown to qualitatively describe the main features of the #betta#-strength functions for decay of 87 Br and 91 93 95 97 Rb. It is found that the location of apparent resonances in the experimental data are in rough agreement with the location of centroids of strength calculated with this model. An extension of the shell model picture which includes the Gamow-Teller residual interaction is used to investigate decay properties of 84 86 As, 86 92 Br and 88 102 Rb. For a realistic choice of interaction strength, the half lives of these isotopes are fairly well reproduced and semiquantitative agreement with experimental #betta#-strength functions is found. Delayed neutron emission probabilities are reproduced for precursors nearer stability with systematic deviations being observed for the heavier nuclei. Contrary to the assumption of a structureless Gamow-Teller giant resonance as embodied gross theory of #betta#-decay, we find that structures in the tail of the Gamow-Teller giant resonances are expected which strongly influence the decay properties of nuclides in this region
Nuclear Structure Calculations for Two-Neutrino Double-β Decay
Directory of Open Access Journals (Sweden)
P. Sarriguren
2016-01-01
Full Text Available We study the two-neutrino double-β decay in 76Ge, 116Cd, 128Te, 130Te, and 150Nd, as well as the two Gamow-Teller branches that connect the double-β decay partners with the states in the intermediate nuclei. We use a theoretical microscopic approach based on a deformed self-consistent mean field with Skyrme interactions including pairing and spin-isospin residual forces, which are treated in a proton-neutron quasiparticle random-phase approximation. We compare our results for Gamow-Teller strength distributions with experimental information obtained from charge-exchange reactions. We also compare our results for the two-neutrino double-β decay nuclear matrix elements with those extracted from the measured half-lives. Both single-state and low-lying-state dominance hypotheses are analyzed theoretically and experimentally making use of recent data from charge-exchange reactions and β decay of the intermediate nuclei.
Chowdhury, Chandra; Jahiruddin, Sheik; Datta, Ayan
2016-04-07
Phosphorene (Pn) is stabilized as a layered material like graphite, yet it possess a natural direct band gap (Eg = 2.0 eV). Interestingly, unlike graphene, Pn exhibits a much richer phase diagram which includes distorted forms like the stapler-clip (black Pn, α form) and chairlike (blue Pn, β form) structures. The existence of these phases is attributed to pseudo-Jahn-Teller (PJT) instability of planar hexagonal P6(6-) rings. In both cases, the condition for vibronic instability of the planar P6(6-) rings is satisfied. Doping with electron donors like tetrathiafulvalene and tetraamino-tetrathiafulvalene and electron acceptors like tetracyanoquinodimethane and tetracyanoethylene convert blue Pn into N-type and black Pn into efficient P-type semiconductors, respectively. Interestingly, pristine blue Pn, an indirect gap semiconductor, gets converted into a direct gap semiconductor on electron or hole doping. Because of comparatively smaller undulation in blue Pn (with respect to black Pn), the van der Waals interactions between the dopants and blue Pn is stronger. PJT distortions for two-dimensional phosphorus provides a unified understanding of structural features and chemical reactivity in its different phases.
Lee, Stephen; Hoffmann, Roald
2002-05-01
Transition metal elements, alloys, and intermetallic compounds often adopt the body centered cubic (bcc) and face centered cubic (fcc) structures. By comparing quantitative density functional with qualitative tight-binding calculations, we analyze the electronic factors which make the bcc and fcc structures energetically favorable. To do so, we develop a tight-binding function, DeltaE(star), a function that measures the energetic effects of transferring electrons within wave vector stars. This function allows one to connect distortions in solids to the Jahn-Teller effect in molecules and to provide an orbital perspective on structure determining deformations in alloys. We illustrate its use by considering first a two-dimensional square net. We then turn to three-dimensional fcc and bcc structures, and distortions of these. Using DeltaE(star), we rationalize the differences in energy of these structures. We are able to deduce which orbitals are responsible for instabilities in seven to nine valence electron per atom (e(-)/a) bcc systems and five and six e(-)/a fcc structures. Finally we demonstrate that these results account for the bcc and fcc type structures found in both the elements and binary intermetallic compounds of group 4 through 9 transition metal atoms. The outline of a theory of metal structure deformations based on loss of point group operation rather than translational symmetry is presented.
Waplak, S
2002-01-01
The EPR (electron paramagnetic resonance) spectra of non-Jahn-Teller (JT) Mn sup 2 sup + and JT Cu sup 2 sup + ions have been studied for alpha- or beta-LAS structure modification in the temperature range of 4.2-480 K. The experimental evidence for JT glass with frozen-in random strain fields due to the presence of the JT Cu sup 2 sup + ions is presented.
Decay Properties of the Halo Nucleus $^{11}$Li
2002-01-01
During the past years a considerable experimental effort has been devoted to the production and study of nuclei close to the neutron and proton drip-lines. The most spectacular phenomenon encountered is the occurrence of neutron halos in the loosely bound neutron rich nuclei. \\\\ \\\\ Another interesting feature, observed at ISOLDE, which most likely is connected to the halo structure, is the very strong (super-allowed) Gamow-Teller $\\beta$- transitions to highly excited states which are systematically observed for the lightest neutron rich drip-line nuclei. These transitions might be viewed as arising from the quasi-free $\\beta$ -decay of the halo neutrons. It is proposed to make a detailed study of the $\\beta$- strength function for $^{11}$Li, a nuclide having a half-life of 8.2 ms and a Q $\\beta$-value of 20.73~MeV. \\\\ \\\\ So far only a lower limit of the Gamow-Teller transition rate to highly excited states ($\\approx$~18.5~MeV) in the daughter nucleus has been obtained from measurements of $\\beta$-delayed tri...
Contribution of the radioactive decay to the study of the structure of N=Z nuclei of mass A>70
International Nuclear Information System (INIS)
Longour, Christophe
1999-01-01
Radioactive decay study gives an access to the interaction which rules the β decay process as well as the structure of the nuclear states involved. This work describes the observation of the decay of N = Z nuclei with mass A > 70. For the odd-odd N = Z nuclei 78 Y, 82 Nb and 86 Tc, the decay has been established as superallowed Fermi type transitions. The results pave the way for more precise measurements and extend the mass range nowadays used to understand the behaviour of the weak interaction in the nuclear matter. The observation of the decay of the even-even N = Z 72 Kr leads us to build the Gamow-Teller strength distribution from which some clues about the ground state deformation of this isotope can be obtained. More complete experimental observation and some developments of the calculations used to interpret the distribution of the Gamow-Teller strength are needed. Finally, this work describes the developments and tests of a prototype detector the aim of which to determine the contribution of β particles to energy distribution observed in germanium detector. The tests we have performed show that this prototype can identify and reject 80% of the β particles emitted by a source with a 2,3 MeV end-point. The very satisfactory performances of this prototype need now to be confirmed under experimental conditions. (author)
Energy Technology Data Exchange (ETDEWEB)
D' Alkaine, C.V.; de O. Brito, G.A. [Group of Electrochemistry and Polymers, DQ-UFSCar, Rodovia Washington Luis, Km 235, CP 676, 13565-905 Sao Carlos (SP) (Brazil)
2009-06-01
We propose an explanation for the production of an electrochemically active area during the electrochemical formation of lead-acid battery negative plates based on solid-state reactions. Our proposal is supported by experimental data. This study includes a critical review of the literature on charge/discharge mechanisms, porosity, and BET area. The critical review, through the latter two parameters, indicates the existence of both macro and micropores in positive plates, but only macropores in negative plates, with characteristic surface roughness. In the present paper the surface sulfation of the precursor is controlled using various acidic, neutral and alkaline solutions during an electrochemical formation process that does not include soaking. Our results confirm that variable roughness can be produced at the negative plate macropore surfaces. The morphological changes produced by different formation conditions are assessed by measuring the macroporosity, BET area, and capacity of single negative plates. Based on these concepts, a method was developed and applied to measure independently the contributions of geometrical surface macroporosity and roughness to the negative plate capacity. (author)
Walén test and de Hoffmann-Teller frame of interplanetary large-amplitude Alfvén waves
International Nuclear Information System (INIS)
Chao, J. K.; Hsieh, Wen-Chieh; Lee, L. C.; Yang, L.
2014-01-01
In this study, three methods of analysis are compared to test the Walén relation. Method 1 requires a good de Hoffmann-Teller (HT) frame. Method 2 uses three components separately to find the frame that is slightly modified from Method 1. This method is intended to improve the accuracy of the HT frame and able to demonstrate the anisotropic property of the fluctuations. The better the relation is, the closer the slope of a regression fitting the data of plasma versus Alfvén velocities is to 1. However, this criterion is based on an average HT frame, and the fitted slope does not always work for the Walén test because the HT frame can change so fast in the high-speed streams. We propose Method 3 to check the Walén relation using a sequence of data generated by taking the difference of two consecutive values of plasma and Alfvén velocities, respectively. The difference data are independent of the HT frame. We suggest that the ratio of the variances between plasma and Alfvén velocities is a better parameter to qualify the Walén relation. Four cases in two solar wind streams are studied using these three methods. Our results show that when the solar wind HT frame remains stable, all three methods can predict Alfvénic fluctuations well, but Method 3 can better predict the Walén relation when solar wind contains structures with several small streams. A simulated case also demonstrates that Method 3 is better and more robust than Methods 1 and 2. These results are important for a better understanding of Alfvénic fluctuations and turbulence in the solar wind.
International Nuclear Information System (INIS)
Hoffmann, S.K.
2000-01-01
Temperature cw-EPR and pulsed EPR electron spin echo experiments were performed for a low concentration of Cu 2+ ions in cubic SrF 2 crystals. The well resolved EPR spectrum at low temperatures (below 30 K) with parameters g parallel = 2.493, g perpendicular = 2.083, A parallel = 121, A perpendicular = 8.7, A parallel ( 19 F) = 135, A parallel ( 19 F) = 33.0 (A-values in 10 -4 cm -1 ) is transformed continuously into a single broad line above 225 K on heating, due to the g-factor shift and EPR line broadening. These data along with the angular variation EPR data are described in terms of a pseudo-Jahn-Teller effect of (T 2g +A 2u )x(a 1g +e g +t 1u ) type producing six off-centre positions of the Cu 2+ ion in the fluorine cube. Above 30 K a two-step averaging g -factor process occurs and is governed by vibronic dynamics between potential wells of the off-centre positions. This dynamics governs the electron spin relaxation in the whole temperature range. The electron spin-lattice relaxation rate 1/T 1 grows rapidly by six orders of magnitude in the temperature range 30-100 K and is determined by the Orbach-type process with excitations to two excited vibronic levels of energy 83 and 174 cm -1 . For higher temperatures the relaxation is dominated by overbarrier jumps leading to the isotropic EPR spectrum above 225 K. The phase memory time T M has the rigid lattice value 3.5 μs determined by nuclear spectral diffusion and its temperature variation is governed by the vibronic dynamics indicating that the excitations between vibronic levels produce a dephasing of the electron spin precessional motion. (author)
Energy Technology Data Exchange (ETDEWEB)
Aguado, F [DCITIMAC, Facultad de Ciencias, Universidad de Cantabria, Santander 39005 (Spain); RodrIguez, F [DCITIMAC, Facultad de Ciencias, Universidad de Cantabria, Santander 39005 (Spain); Valiente, R [Departamento de Fisica Aplicada, Universidad de Cantabria, Santander 39005 (Spain); Hanfland, M [ESRF, BP220, 156 rue des Martires, 38043 Grenoble Cedex (France); Itie, J P [Universite Pierre et Marie Curie, B77 4 Place Jussieu 75252 Paris Cedex 05 (France)
2007-08-29
This work investigates the effect of pressure on the Jahn-Teller distortion (JTD) associated with the axially elongated CuCl{sub 6} octahedra in the A{sub 2}CuCl{sub 4} perovskite layer (A: Rb, CH{sub 3}NH{sub 3}, C{sub 2}H{sub 5}NH{sub 3}, C{sub 3}H{sub 7}NH{sub 3}). The aim is to elucidate whether pressure favours disappearance of the JTD in the antiferrodistortive (AFD) structure exhibited by Cu{sup 2+} within the layers or whether it induces tilts of the CuCl{sub 6} octahedra preserving the molecular distortion associated with the JT effect. We have carried out x-ray absorption (XAS) and x-ray diffraction (XRD) experiments under pressure along the compound series, whose interlayer distances at ambient pressure vary from 7.77 to 12.33 A. The use of both XAS and XRD techniques allows us a complete local- and crystal-structure characterization in Rb{sub 2}CuCl{sub 4} as a function of pressure in the 0-16 GPa range. We show that pressure reduces the axial (long) and equatorial (short) Cu-Cl distances, R{sub ax} and R{sub eq}, as well as the intralayer and interlayer Cu-Cu distances, d{sub Cu-Cu} and d{sub inter}. Interestingly, the variation of R{sub ax} is an order of magnitude bigger than that of the corresponding R{sub eq}, yielding a reduction of the JTD. However, no evidence of JTD suppression has been observed below 16 GPa. Pressure-induced CuCl{sub 6} tilting preserves the JTD in a wide pressure range. Estimates based on structural data suggest that JT suppression would occur at about 40 GPa.
International Nuclear Information System (INIS)
Aguado, F; RodrIguez, F; Valiente, R; Hanfland, M; Itie, J P
2007-01-01
This work investigates the effect of pressure on the Jahn-Teller distortion (JTD) associated with the axially elongated CuCl 6 octahedra in the A 2 CuCl 4 perovskite layer (A: Rb, CH 3 NH 3 , C 2 H 5 NH 3 , C 3 H 7 NH 3 ). The aim is to elucidate whether pressure favours disappearance of the JTD in the antiferrodistortive (AFD) structure exhibited by Cu 2+ within the layers or whether it induces tilts of the CuCl 6 octahedra preserving the molecular distortion associated with the JT effect. We have carried out x-ray absorption (XAS) and x-ray diffraction (XRD) experiments under pressure along the compound series, whose interlayer distances at ambient pressure vary from 7.77 to 12.33 A. The use of both XAS and XRD techniques allows us a complete local- and crystal-structure characterization in Rb 2 CuCl 4 as a function of pressure in the 0-16 GPa range. We show that pressure reduces the axial (long) and equatorial (short) Cu-Cl distances, R ax and R eq , as well as the intralayer and interlayer Cu-Cu distances, d Cu-Cu and d inter . Interestingly, the variation of R ax is an order of magnitude bigger than that of the corresponding R eq , yielding a reduction of the JTD. However, no evidence of JTD suppression has been observed below 16 GPa. Pressure-induced CuCl 6 tilting preserves the JTD in a wide pressure range. Estimates based on structural data suggest that JT suppression would occur at about 40 GPa
Effective axial-vector strength and β-decay systematics
Delion, D. S.; Suhonen, J.
2014-09-01
We use the weak axial-vector coupling strength g_{\\text{A}} as a key parameter to reproduce simultaneously the available data for both the Gamow-Teller \\beta^- and \\beta^+/\\text{EC} decay rates in nine triplets of isobars with mass numbers A=70,78,100,104,106,110,116,128,130 . We use the proton-neutron quasiparticle random-phase approximation (pnQRPA) with schematic dipole interaction containing particle-particle and particle-hole parts with mass-dependent strengths. Our analysis points to a strongly quenched effective value g_{\\text{A}}\\approx 0.3 , with a relative error of 28%. We then perform a systematic computation of 218 experimentally known \\beta^- and \\beta^+/\\text{EC} decays with quite a remarkable success. The presently extracted value of g_{\\text{A}} should be taken as an effective one, specific for a given nuclear theory framework. Present studies suggest that the effective g_{\\text{A}} is suitable for the description of decay transitions to 1^+ states at moderate excitation, below the Gamow-Teller giant resonance region.
International Nuclear Information System (INIS)
Sharp, R.R. Jr.; Hill, D.E.
1978-05-01
During July-August 1976, 2026 natural waters and 2085 bottom sediments were collected from 2209 sample locations (at a nominal density of one location each 23 km 2 ) on streams and small lakes throughout the Teller, Bendeleben, Candle, and western one-third of the Kateel River NTMS quadrangles, Alaska. Total uranium was measured in the waters by fluorometry and in the sediments and a few waters by delayed-neutron counting. The uranium content of the waters ranged from below the detection limit of 0.02 parts per billion (ppB) to a high of 14.50 ppB, averaging 0.44 ppB, and that of the sediments ranged from a low of 0.2 parts per million (ppM) to a high of 107.4 ppM, averaing 3.93 ppM. The uranium data for water and sediment are separately presented--as computer listings that include pertinent field measurements from each location, as graphically portrayed concentration overlays at 1:250,000 scale for each quadrangle, and as reduced figures showing contours drawn at various concentration levels for each quadrangle--and their areal distributions are compared and correlated with the known features and uranium showings. A test of increasingly detailed methods of data evaluation shows that the more extensive the evaluation, the more useful the reconnaissance uranium data are likely to be. The validity and potential usefulness of the HSSR uranium data are conclusively substantiated by the fact that evidence of all 23 of the reported uranium showings in the 50,000-km 2 study area can be discerned. Several new locations of interest for further field investigation are identified in each of the quadrangles, and most notably in the Bendeleben Mountains. However, the data presented would appear equally useful in guiding field investigation around the uranium occurrences already known, as noteworthy samples often come from close by but on tributary drainages adjacent, opposite, or above them
Nucleon charge-exchange reactions at intermediate energy
International Nuclear Information System (INIS)
Alford, W.P.; Spicer, B.M.
1997-01-01
An historical review of the development of ideas pertaining to Gamow-Teller giant resonances is given, and a description of the emergence of techniques for the study of charge exchange reactions - particularly the technical advances which yielded the recent volume of new date. The present status of charge exchange reactions is reviewed and assessed. Evidence is presented from the 14 C(p,n) reaction for the dominance of the spin-isospin component of the nucleon-nucleon interaction in intermediate energy reactions. In (p,n) reactions the Gamow-Teller giant resonance dominates the spectra, with higher multipoles contributing. By contrast, in (n,p) reactions in the heavier nuclei, the Gamow-Teller transitions are substantially Pauli-blocked and the spin dipole resonance dominates, with contributions from higher multipoles. Discussions of the multipole decomposition process, used to obtain from the data the contributions of the different multipoles, and the contributions of the multipoles, are given
The beta strength function structure in β+ decay of lutetium, thulium and cesium isotopes
International Nuclear Information System (INIS)
Alkhazov, G.D.; Bykov, A.A.; Vitman, V.D.; Naumov, Yu.V.; Orlov, S.Yu.
1981-01-01
The spectra of total γ-absorption in the decays of some Lutecium, Thulium and Cesium isotopes have been measured. The probabilities for level population in the decay of the isotopes have been determined. The deduced beta strength functions reveal pronounced structure. Calculations of the strength functions using the Saxon-Woods potential and the residual Gamow-Teller interaction are presented. It is shown that in β + decay of light Thulium and Cesium isotopes the strength function comprises more than 70% of the Gamow-Teller excitations with μsub(tau) = +1. This result is the first direct observation of the Gamow-Teller resonance in β + decay of nuclei with Tsub(z) > O. (orig.)
Nucleus as a chiral filter: the role of the Δ(1232)
International Nuclear Information System (INIS)
Rho, Mannque.
1982-03-01
We describe how two different modes of chiral symmetry can be seen in nuclei. In particular, it is shown that the nuclear axial charge or more precisely the O + O - , ΔT=1 transition at zero momentum transfer probe the nuclear configuration wherein the axial charge gsub(A) is effectively enhanced in nuclear medium due to soft pions, symptomatic of the Goldstone realization of chiral symmetry in the medium while the Gamow-Teller resonances probe the configuration wherein soft pions are no longer operative, suggesting an approach toward the Wigner realization of chiral symmetry. Using the celebrated Adler-Weisberger relation, it is argued that the observed approximately 50% quenching of the Gamow-Teller strength reflects the possibility that the Gamow-Teller operator sees the quarks inside the bag, blind to the Goldstone vacuum outside. Some implications on chiral phase transitions are also discussed
Isovector excitations in charge independent systems
International Nuclear Information System (INIS)
Menezes, D.P.
1986-01-01
A method for building states with good isospin, from states given by the action of an isovector excitation operator on states of the parent multiplet is developed. This new method is a generalization of Toki's method and is applicable to cases involving any isovector excitation operator and a parent state, which is not a double magic nucleus. Once obtained these states with well defined isospin, it is shown how to do a Tamm-Dancoff calculation for determining the energy levels. The transition matrix elements of an isotensor operator are also calculated. An application of this formalism to the Gamow-Teller transition strength in 90 Zr is studied. In this case, besides the double magic configuration, the 2 particles - 2 holes (Π1g 9/2 ) 2 (υ 2p 1/2 -1 ) 2 configuration is also considered. (author) [pt
Sum rules for nuclear excitations with the Skyrme-Landau interaction
International Nuclear Information System (INIS)
Liu Kehfei; Luo Hongde; Ma Zhongyu; Feng Man; Shen Qingbiao
1991-01-01
The energy-weighted sum rules for electric, magnetic, Fermi and Gamow-Teller transitions with the Skyrme-Landau interaction are derived from the double commutators and numerically calculated in a HF + RPA formalism. As a numerical check of the Thouless theorem, our self-consistent calculations show that the calculated RPA strengths exhaust more than 85% of the sum rules in most cases. The well known non-energy-weighted sum rules for Fermi and Gamow-Teller transitions are also checked numerically. The sum rules are exhausted by more than 94% in these cases. (orig.)
DEFF Research Database (Denmark)
Reynisson, J.; Wilbrandt, R.; Brinck, V.
2002-01-01
. The physical and chemical properties of the excited singlet state of the trioxatriangulenium (TOTA(+)) carbenium ion are investigated by experimental and Computational means. The degeneracy of the lowest excited states is counteracted by Jahn-Teller-type distortion, which leads to vibronic broadening...... of the long wavelength absorption band. A strong fluorescence is observed at 520 nm (tau(n) = 14.6 ns, phi(n) = 0.12 in deaerated acetonitrile). The fluorescence is quenched by 10 aromatic electron donors predominantly via a dynamic charge transfer mechanism, but ground state complexation is shown...... triphenylenes is studied separately. Phosphorescence spectra, triplet lifetimes, and triplet-triplet absorption spectra are provided. In the discussion, TOTA(+) is compared to the unsubstituted xanthenium ion and its 9-phenyl derivative with respect to the excited state properties....
International Nuclear Information System (INIS)
Bengtsson, R.; Krumlinde, J.; Moeller, P.; Nix, J.R.; Zhang, J.
1983-01-01
We study nuclear potential-energy surfaces, ground-state masses and shapes calculated by use of a Yukawa-plus-exponential macroscopic model and a folded-Yukawa single-particle potential for 4023 nuclei ranging from 16 O to 279 112. We discuss extensively the transition from spherical to deformed shapes and study the relation between shape changes and the mass corresponding to the ground-state minimum. The calculated values for the ground-state mass and shape show good agreement with experimental data throughout the periodic system, but some discrepancies remain that deserve further study. We also discuss the effect of deformation on Gamow-Teller #betta#-strength functions
International Nuclear Information System (INIS)
Pratiwi, B N; Suparmi, A; Cari, C; Yunianto, M; Husein, A S
2016-01-01
We apllied asymptotic iteration method (AIM) to obtain the analytical solution of the Dirac equation in case exact pseudospin symmetry in the presence of modified Pcischl- Teller potential and trigonometric Scarf II non-central potential. The Dirac equation was solved by variables separation into one dimensional Dirac equation, the radial part and angular part equation. The radial and angular part equation can be reduced into hypergeometric type equation by variable substitution and wavefunction substitution and then transform it into AIM type equation to obtain relativistic energy eigenvalue and wavefunctions. Relativistic energy was calculated numerically by Matlab software. And then relativistic energy spectrum and wavefunctions were visualized by Matlab software. The results show that the increase in the radial quantum number n_r causes decrease in the relativistic energy spectrum. The negative value of energy is taken due to the pseudospin symmetry limit. Several quantum wavefunctions were presented in terms of the hypergeometric functions. (paper)
The {sup 152}Sm(p,n) reaction measurements in inverse kinematics
Energy Technology Data Exchange (ETDEWEB)
Pohl, Moritz [Goethe Univ. Frankfurt am Main (Germany); Collaboration: S405-Collaboration
2013-07-01
Under stellar conditions, low-lying excited states in nuclei are in thermal equilibrium with the ground state. If those excited states undergo β-decays with a higher rate than the ground state, the β-decay half-life of this nucleus is dominated by the excited state. The corresponding life-times are extremely difficult to measure directly on earth, since the de-excitation occurs mostly via internal transition. For the understanding of the processes occurring during a star collapse, simulations are a crucial tool. To provide a detailed view on those processes and the underlying theoretical models, also to test and improve the simulation networks, information extracted from experiments is needed. Unfortunately, some reactions can not be reproduced directly in laboratories. This applies for example to electron capture processes, which can lead to excited states energetically forbidden on earth. Those reactions are dominated by the so called Gamow-Teller distribution B(GT). If the β-decay occurs via the Gamow-Teller transition, charge exchange reactions allow to investigate the decay strength. In order to verify the method of measuring the B(GT) strength of unstable heavy nuclei via inverse kinematics, the reaction p({sup 152}Sm,{sup 152}Eu)n was used as a test case. This measurement allows to set constraints on the temperature dependent electron capture of {sup 152}Eu, which is an important s-process branching point. The s405 experiment took place at the R{sup 3}B/LAND setup at GSI. A newly developed Low Energy Neutron detector Array (LENA) was used to measure the recoil neutrons, which are emitted at large angles relatively to the incoming beam. To determine the detector response, a GEANT3 simulation was performed. Preliminary results are presented.
Search for the signature of a halo structure in the p(6He,6Li)n reaction
International Nuclear Information System (INIS)
Cortina-Gil, M.D.; Roussel-Chomaz, P.; Mittig, W.; Casandjian, J.M.; Chartier, M.; Alamanos, N.; Auger, F.; Fekou-Youmbi, V.; Blumenfeld, Y.; and others.
1995-01-01
The elastic scattering p( 6 He, 6 He)p and charge exchange reaction p( 6 He, 6 Li)n have been measured in reverse kinematics with a secondary 6 He beam. The angular distributions for these reactions were obtained. In the case of the charge exchange reaction, the ratio of the cross section for the Gamow-Teller transition to the ground state, and for the Fermi transition to the isobaric analog state is a measure of the relative strength of the two components of the exchange interaction. This ratio is found compatible with existing systematics for stable T=1 nuclei, and no clear signature of a halo structure was found in the present data. (author)
Meson exchange currents in nuclei; the triton beta decay as an example
International Nuclear Information System (INIS)
Jaus, W.
1976-01-01
The method used to reduce the four-dimensional Bethe-Salpeter equation to the three-dimensional Schroedinger equation, thus defining a potential in terms of the field theoretic interaction, can be generalized to define a consistent exchange by considering the relativistic interaction of a current with a bound state of nucleons. This covariant approach allows a unified treatment of exchange current effects, renormalization of the nuclear wave function due to meson exchange, relativistic corrections and negative energy contributions to the wave function and it is discussed in detail how these effects influence the Gamow-Teller matrix element for the decay 3 H→ 3 He + e + antiγ. One and two-meson exchange processes are calculated including nucleon resonances in intermediate states, and good agreement of theoretical and experimental predictions for the GT matrix element is found. (Auth.)
International Nuclear Information System (INIS)
Onishi, T K; Gelberg, A; Sakurai, H; Yoneda, K; Aoi, N; Imai, N; Baba, H; Brentano, P von; Fukuda, N; Ichikawa, Y; Ishihara, M; Iwasaki, H; Kameda, D; Kishida, T; Lisetskiy, A F; Ong, H J; Osada, M; Otsuka, T; Suzuki, M K; Ue, K; Utsuno, Y; Watanabe, H
2006-01-01
The Gamow-Teller transition of 46 Cr to the N = Z odd-odd nucleus 46 V has been observed for the first time. By means of β-γ coincidence measurements, a γ-ray peak at 993 keV corresponding to the decay of the 1 + 1 state in 46 V was observed. The branching ratio of the decay to this state was found to be b GT = 0.25 ± 0.050. The half-life of 46 Cr was measured to be T 1/2 = 240 ± 140 ms. The transition strength was determined to be B(GT) = 0.64 ± 0.20. This result was compared with theoretical calculations
Studies of the fluorescent excited state of impurities in ionic crystals
International Nuclear Information System (INIS)
Romestain, Robert
1972-01-01
The author of this research thesis first presents experimental methods used in this research: principles (recall on the optical spectrum of an impurity in a solid, use of fluorescence polarization) and techniques (sample preparation, liquid helium cryostat, application of a disturbance, optical detection). Then, he reports the study of the Mn ++ ion in a tetrahedron crystalline field, the study of the Jahn Teller effect on the excited state of the F + centre in CaO, and the study by double resonance of a specific excited state of this same centre in CaO
Spectroscopy of the doubly magic nucleus {sup 100}Sn and its decay
Energy Technology Data Exchange (ETDEWEB)
Hinke, Christoph B.
2010-07-23
The nucleus {sup 100}Sn has been the aim of a number of experimental approaches. It is of great interest for various reasons. It is presumably the heaviest particle-stable N=Z nucleus and at the same time doubly magic. Its beta decay is of particular importance because it is expected to be the purest Gamow-Teller decay in the nuclear chart and thus allows to study the question of the missing Gamow-Teller strength/the Gamow-Teller quenching due to core polarisation effects. From the beta-coincident decay spectroscopy of the daughter nucleus {sup 100}In information about the proton-neutron interaction in this region of the nuclear chart can be obtained. Simultaneously with the implantation of the nucleus in the detector setup after production the search for delayed gamma radiation from a predicted isomeric state in {sup 100}Sn could yield first insight into the structure of excited states in this exotic nucleus. This work presents investigation results concerning the spectroscopy of the doubly magic nucleus {sup 100}Sn and its decay. The experiment was performed in March 2008 at the accelerator facilities of the GSI Helmholtz Zentrum Darmstadt. The neutron deficient nucleus was produced in a projectile fragmentation reaction of a {sup 124}Xe primary beam impinging on a Beryllium target with an energy of 1 GeV x A. After a separation from other fragmentation products and a unique identification {sup 100}Sn was stopped in an implantation detector consisting of highly segmented silicon strip detectors for decay spectroscopy. Beside the determination of the half life it was possible to detect the total energy of the emitted particle radiation in the implantation detector as well as the emitted gamma radiation with a surrounding array of Germanium detectors. With a number of approximately 70 successfully observed decays of {sup 100}Sn a half life of T{sub 1/2}=1.16{+-}0.20s was obtained. The beta endpoint energy of the single channel decay yielded a value of E{sub {beta
Spectroscopy of the doubly magic nucleus 100Sn and its decay
International Nuclear Information System (INIS)
Hinke, Christoph B.
2010-01-01
The nucleus 100 Sn has been the aim of a number of experimental approaches. It is of great interest for various reasons. It is presumably the heaviest particle-stable N=Z nucleus and at the same time doubly magic. Its beta decay is of particular importance because it is expected to be the purest Gamow-Teller decay in the nuclear chart and thus allows to study the question of the missing Gamow-Teller strength/the Gamow-Teller quenching due to core polarisation effects. From the beta-coincident decay spectroscopy of the daughter nucleus 100 In information about the proton-neutron interaction in this region of the nuclear chart can be obtained. Simultaneously with the implantation of the nucleus in the detector setup after production the search for delayed gamma radiation from a predicted isomeric state in 100 Sn could yield first insight into the structure of excited states in this exotic nucleus. This work presents investigation results concerning the spectroscopy of the doubly magic nucleus 100 Sn and its decay. The experiment was performed in March 2008 at the accelerator facilities of the GSI Helmholtz Zentrum Darmstadt. The neutron deficient nucleus was produced in a projectile fragmentation reaction of a 124 Xe primary beam impinging on a Beryllium target with an energy of 1 GeV x A. After a separation from other fragmentation products and a unique identification 100 Sn was stopped in an implantation detector consisting of highly segmented silicon strip detectors for decay spectroscopy. Beside the determination of the half life it was possible to detect the total energy of the emitted particle radiation in the implantation detector as well as the emitted gamma radiation with a surrounding array of Germanium detectors. With a number of approximately 70 successfully observed decays of 100 Sn a half life of T 1/2 =1.16±0.20s was obtained. The beta endpoint energy of the single channel decay yielded a value of E β 0 =3.29±0.20 MeV. The resultant Gamow-Teller
International Nuclear Information System (INIS)
Saito, T.Y.; Wu, Y.; Ishikawa, S.; Sasakawa, T.
1990-01-01
Triton β-decay has been calculated using wave functions for 3 He and 3 H obtained from (Coulomb-modified) Faddeev equations for various interactions. We get a value for the Gamow-Teller matrix element of √3 (0.962±0.002) without regards to two- or three-nucleon inteactions. This value agrees with the experimental value. (orig.)
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
Charge exchange probes of nuclear structure and interactions with emphasis on (p,n)
International Nuclear Information System (INIS)
Goodman, C.D.
1980-01-01
New results from (p,n) studies at IUCF show that it is possible to observe Gamow-Teller (GT) strength and extract GT matrix elements from (p,n) measurements. The charge exchange reactions ( 6 Li, 6 He) and (π + ,π 0 ) involve different projectile quantum numbers, and the relationships of these reactions to (p,n) is discussed
Low-energy Electro-weak Reactions
International Nuclear Information System (INIS)
Gazit, Doron
2012-01-01
Chiral effective field theory (EFT) provides a systematic and controlled approach to low-energy nuclear physics. Here, we use chiral EFT to calculate low-energy weak Gamow-Teller transitions. We put special emphasis on the role of two-body (2b) weak currents within the nucleus and discuss their applications in predicting physical observables.
Searches for exotic interactions in nuclear beta decay
Energy Technology Data Exchange (ETDEWEB)
Naviliat-Cuncic, O. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, 640 S Shaw Lane, East Lansing MI 48824 (United States)
2016-07-07
This contribution presents current efforts in the search for exotic interactions in nuclear β decay using a calorimetric technique for the measurement of the β energy spectrum shape. We describe the criteria for the choice of sensitive candidates in Gamow-Teller transitions and present the status of measurements performed in {sup 6}He and {sup 20}F decay.
Prof. Ikeda’s important contributions to nuclear physics
Brink, D M
2010-01-01
Professor Ikeda has made many fundamental contributions to nuclear physics, especially to the theory of Gamow-Teller giant resonances, to nuclear cluster physics, to hypernuclear physics, and to the physics of neutron-rich nuclei. He also has played an important role in the education of young researchers in Japan and on the contacts between theoreticians and experimentalists.
Configuration mixing for spin-isospin modes
International Nuclear Information System (INIS)
Ichimura, Munetake
2005-01-01
Development of theories of configuration mixing is reviewed, concentrating on their application to spin-isospin modes, especially to the Gamow-Teller transitions. This talk is divided into three historical stages, the first order configuration mixing as the first stage, the second order configuration mixing as the second stage, and the delta-isobar-hole mixing as the third stage
Structure of the two-neutrino double-β decay matrix elements within perturbation theory
Štefánik, Dušan; Šimkovic, Fedor; Faessler, Amand
2015-06-01
The two-neutrino double-β Gamow-Teller and Fermi transitions are studied within an exactly solvable model, which allows a violation of both spin-isospin SU(4) and isospin SU(2) symmetries, and is expressed with generators of the SO(8) group. It is found that this model reproduces the main features of realistic calculation within the quasiparticle random-phase approximation with isospin symmetry restoration concerning the dependence of the two-neutrino double-β decay matrix elements on isovector and isoscalar particle-particle interactions. By using perturbation theory an explicit dependence of the two-neutrino double-β decay matrix elements on the like-nucleon pairing, particle-particle T =0 and T =1 , and particle-hole proton-neutron interactions is obtained. It is found that double-β decay matrix elements do not depend on the mean field part of Hamiltonian and that they are governed by a weak violation of both SU(2) and SU(4) symmetries by the particle-particle interaction of Hamiltonian. It is pointed out that there is a dominance of two-neutrino double-β decay transition through a single state of intermediate nucleus. The energy position of this state relative to energies of initial and final ground states is given by a combination of strengths of residual interactions. Further, energy-weighted Fermi and Gamow-Teller sum rules connecting Δ Z =2 nuclei are discussed. It is proposed that these sum rules can be used to study the residual interactions of the nuclear Hamiltonian, which are relevant for charge-changing nuclear transitions.
Jahn-Teller effect in van der Waals complexes; Ar-C6H6 + and Ar-C6D6 +.
Avoird, A. van der; Lotrich, VF
2004-01-01
The two asymptotically degenerate potential energy surfaces of argon interacting with the X (2)E(1g) ground state benzene(+) cation were calculated ab initio from the interaction energy of the neutral Ar-benzene complex given by Koch et al. [J. Chem. Phys. 111, 198 (1999)] and the difference of the
De Witte, H; Borzov, I N; Caurier, E; Cederkäll, J; De Smet, A; Eckhaudt, S; Fedorov, D V; Fedosseev, V; Franchoo, S; Górska, M; Grawe, H; Huber, G; Huyse, M; Janas, Z; Köster, U; Kurcewicz, W; Kurpeta, J; Plochocki, A; Van Duppen, P; Van de Vel, K; Weissman, L
2004-01-01
The neutron-rich isotope /sup 218/Bi has been produced in proton- induced spallation of a uranium carbide target at the ISOLDE facility at CERN, extracted from the ion source by the pulsed-release technique and resonant laser ionization, and its beta decay is studied for the first time. A half-life of 33(1)s was measured and is discussed in the self-consistent continuum-quasi particle-random- phase approximation framework that includes Gamow-Teller and first- forbidden transitions. A level scheme was constructed for /sup 218 /Po, and a deexcitation pattern of stretched E2 transitions 8/sup +/ to 6/sup +/ to 4/sup +/ to 2/sup +/ to 0/sup +/ to the ground state is suggested. Shell-model calculations based on the Kuo-Herling interaction reproduce the experimental results satisfactorily. (28 refs).
Evolution of single-particle structure and beta-decay near 78Ni
Directory of Open Access Journals (Sweden)
Borzov I. N.
2012-12-01
Full Text Available The extended self-consistent beta-decay model has been applied for bet-decay rates and delayed neutron emission probabilities of spherical neutron-rich isotopes near the r-process paths. Unlike a popular global FRDM+RPA model, in our fully microscopic approach, the Gamow-Teller and first-forbidden decays are treated on the same footing. The model has been augmented by blocking of the odd particle in order to account for important ground-state spin-parity inversion effect which has been shown to exist in the region of the most neutron-rich doubly-magic nucleus 78Ni. Finally, a newly developed form of density functional DF3a has been employed which gives a better spin-orbit splitting due to the modified tensor components of the density functional.
International Nuclear Information System (INIS)
Haeusser, O.; Sawafta, R.; Jeppesen, R.G.
1988-01-01
Forward-angle cross sections for 1 + , T = 1 and 1 + , T = 0 states in 28 Si excited by the (p,p') reaction have been measured to determine the energy dependence of important pieces of the effective nucleon-nucleus interaction. The isovector spin-transfer transitions depend on energy as expected from distorted-wave impulse approximation calculations based on the dominant V/sub Σ//sub tau/ part of the Franey-Love interaction. The parts of this interaction responsible for exciting the 9.5 MeV isosca- lar spin-flip transition predict a weaker energy dependence than is observed experimentally. The summed Gamow-Teller strength for isovector transitions below 14.5 MeV is found to be (0.89 +- 0.09) times the result of large-scale shell model calculations
Isospin Mixing In N $\\approx$ Z Nuclei
Srnka, D; Versyck, S; Zakoucky, D
2002-01-01
Isospin mixing in N $\\approx$ Z nuclei region of the nuclear chart is an important phenomenon in nuclear physics which has recently gained theoretical and experimental interest. It also forms an important nuclear physics correction in the precise determination of the $ft$-values of superallowed 0$^+ \\rightarrow 0^+ \\beta$- transitions. The latter are used in precision tests of the weak interaction from nuclear $\\beta$- decay. We propose to experimentally measure isospin mixing into nuclear ground states in the N $\\approx$ Z region by determining the isospin forbidden Fermi-component in the Gamow-Teller dominated $J^{\\pi} \\rightarrow J^{\\pi} \\beta$- transitions through the observation of anisotropic positron emission from oriented nuclei. First measurements were carried out with $^{71}$As and are being analyzed now.
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.
Towards the improvement of spin-isospin properties in nuclear energy density functionals
International Nuclear Information System (INIS)
Roca-Maza, X.; Colò, G.; Liang, H. Z.; Sagawa, H.; Meng, J.; Ring, P.; Zhao, P. W.
2016-01-01
We address the problem of improving existing nuclear Energy Density Functionals (EDFs) in the spin-isospin channel. For that, we propose two different ways. The first one is to carefully take into account in the fitting protocol some of the key ground state properties for an accurate description of the most studied spin-isospin resonances: the Gamow-Teller Resonance (GTR) [1]. The second consists in providing a strategy to build local covariant EDF keeping the main features from their non-local counterparts [2]. The RHF model based on a Lagrangian where heavy mesons carry the nuclear effective interaction have been shown to be successful in the description of spin-isospin resonances [3]. (paper)
Taddeucci, T. N.; Rapaport, J.; Bainum, D. E.; Goodman, C. D.; Foster, C. C.; Gaarde, C.; Larsen, J.; Goulding, C. A.; Horen, D. J.; Masterson, T.; Sugarbaker, E.
1982-02-01
Information concerning the ratio of the isovector effective interaction strengths |JστJτ| may be obtained from the ratio of (p,n) Gamow-Teller and isobaric analog state 0° differential cross sections. We have examined 0° (p,n) data for the energy range 5-200 MeV and find that for energies larger than 50 MeV and for targets with A=7-42 the product of the interaction-strength and distortion-factor ratios |JστJτ|(NστNτ)12 appears to be mass independent and linear as a function of bombarding energy. NUCLEAR REACTIONS 7Li, 13, 14C, 26Mg, 37Cl, 41Ca(p,n), measured σ(θ=0°), GT, IAS transitions, Ep=60-200 MeV. Deduced energy dependence, interaction strength ratio |JστJτ|.
International Nuclear Information System (INIS)
Paar, N.; Niksic, T.; Marketin, T.; Vretenar, D.; Ring, P.
2005-01-01
The excitation phenomena in unstable nuclei are investigated in the framework of the relativistic quasiparticle random-phase approximation (RQRPA) in the relativistic Hartree-Bogolyubov model (RHB) which is extended to include effective interactions with explicit density-dependent meson-nucleon couplings. The properties of the pygmy dipole resonance (PDR) are examined in 132 Sn and within isotopic chains, showing that already at moderate proton-neutron asymmetry the PDR peak energy is located above the neutron emission threshold. A method is suggested for determining the size of the neutron skin within an isotopic chain, based on the measurement of the excitation energies of the Gamow-Teller resonance relative to the isobaric analog state. In addition, for the first time the relativistic RHB+RQRPA model, with tensor ω meson-nucleon couplings, is employed in calculations of β-decay half-lives of nuclei of the relevance for the r-process. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Paar, N. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); University of Zagreb, Physics Department, Faculty of Science (Croatia); University of Washington, Institute for Nuclear Theory, Seattle (United States); Niksic, T. [University of Zagreb, Physics Department, Faculty of Science (Croatia); University of Washington, Institute for Nuclear Theory, Seattle (United States); Marketin, T.; Vretenar, D. [University of Zagreb, Physics Department, Faculty of Science (Croatia); Ring, P. [Physik-Department der Technischen Universitaet Muenchen, Garching (Germany)
2005-09-01
The excitation phenomena in unstable nuclei are investigated in the framework of the relativistic quasiparticle random-phase approximation (RQRPA) in the relativistic Hartree-Bogolyubov model (RHB) which is extended to include effective interactions with explicit density-dependent meson-nucleon couplings. The properties of the pygmy dipole resonance (PDR) are examined in {sup 132}Sn and within isotopic chains, showing that already at moderate proton-neutron asymmetry the PDR peak energy is located above the neutron emission threshold. A method is suggested for determining the size of the neutron skin within an isotopic chain, based on the measurement of the excitation energies of the Gamow-Teller resonance relative to the isobaric analog state. In addition, for the first time the relativistic RHB+RQRPA model, with tensor {omega} meson-nucleon couplings, is employed in calculations of {beta}-decay half-lives of nuclei of the relevance for the r-process. (orig.)
Beta decay and muon capture rates in a self-consistent relativistic framework
Energy Technology Data Exchange (ETDEWEB)
Marketin, Tomislav; Paar, Nils; Niksic, Tamara; Vretenar, Dario [Physics Department, Faculty of Science, University of Zagreb (Croatia); Ring, Peter [Physik-Department, Technische Universitaet Muenchen, D-85748 Muenchen (Germany)
2009-07-01
A fully consistent calculation of muon capture and beta decay rates is presented, based on a microscopic theoretical framework describing the semileptonic weak interaction processes. Nuclear ground state is determined using the Relativistic Hartree-Bogolyubov (RHB) model with density dependent meson-nucleon coupling constants, and transition rates are calculated via proton-neutron relativistic quasiparticle RPA using the same interaction as in the RHB equations. Muon capture rates are calculated for a wide range of nuclei along the valley of stability, from {sup 12}C to {sup 244}Pu, with accuracy of approximately 30%, using the interaction DD-ME2. Previous studies of beta decay rates have only taken into account Gamow-Teller transitions. We extend this approach by including forbidden transitions and systematically study their contribution to decay rates of exotic nuclei along the r-process path, which are important for constraining the conditions in which nucleosynthesis takes place.
And Gamow said, Let there be a Hot Universe
Indian Academy of Sciences (India)
of relativity, in 1915, to describe the nature of space and time, the ... past, there would have been no space between the stars. Even earlier ... Big Bang. Fusion, not Fission. Lemaitre had suggested that after starting off as the. 'primeval atom', the Universe would split into subatomic particles by repeated fission. Yet, spectra of ...
Hosain, M. A.; Le Floch, J.-M.; Krupka, J.; Tobar, M. E.
2018-01-01
The impurity paramagnetic ion, Cu2+ substitutes Al in the SrLaAlO4 single crystal lattice, this results in a CuO6 elongated octahedron, and the resulting measured g-factors satisfy four-fold axes variation condition. The aggregate frequency width of the electron spin resonance with the required minimum level of impurity concentration has been evaluated in this single crystal SrLaAlO4 at 20 millikelvin. Measured parallel hyperfine constants, A\\Vert Cu , were determined to be -155.7×10-4~cm-1, ~ -163.0×10-4~cm-1, ~ -178.3×10-4~cm-1 and -211.1×10-4~cm-1 at 9.072~GHz~(WGH4, 1, 1) for the nuclear magnetic quantum number M_I=+\\frac{3}{2}, +\\frac{1}{2}, -\\frac{1}{2} , and -\\frac{3}{2} respectively. The anisotropy of the hyperfine structure reveals the characteristics of the static Jahn-Teller effect. The second-order-anisotropy term, ˜ (\\fracspin{-orbit~coupling}{10D_q}){\\hspace{0pt}}2 , is significant and cannot be disregarded, with the local strain dominating over the observed Zeeman-anisotropy-energy difference. The Bohr electron magneton, β=9.23× 10-24 JT-1 , (within -0.43% so-called experimental error) has been found using the measured spin-Hamiltonian parameters. Measured nuclear dipolar hyperfine structure parameter P\\Vert=12.3×10-4~cm-1 shows that the mean inverse third power of the electron distance from the nucleus is ≃ 5.23 a.u. for Cu2+ ion in the substituted Al3+ ion site assuming nuclear electric quadruple moment Q=-0.211 barn.
Ulanov, V A; Hoffmann, S K; Zaripov, M M
2003-01-01
Pressure and temperature variations of the spin-Hamiltonian parameters and electron paramagnetic resonance (EPR) linewidths of non-central Jahn-Teller [CuF sub 4 F sub 4] sup 6 sup - complexes in SrF sub 2 crystal were studied by continuous-wave EPR. It was found that the static spin-Hamiltonian parameters, found at T = 85 K and at normal pressure (g sub | sub | = 2.491, g sub p sub e sub r sub p sub e sub n sub d sub i sub c sub u sub l sub a sub r = 2.083, a sub p sub a sub r sub a sub l sub l sub e sub l = 360, a sub p sub e sub r sub p sub e sub n sub d sub i sub c sub u sub l sub a sub r = 26, A sub x sub ' sub ' = 96, A sub y sub ' sub ' = 99, A sub z sub ' sub ' = 403 and beta sub e sub x sub p = 17 diameter), are slightly changed with hydrostatic pressure and, at T = 85 K and P = 550 MPa, become equal to g sub | sub | = 2.489, g sub p sub e sub r sub p sub e sub n sub d sub i sub c sub u sub l sub a sub r = 2.083, a sub | sub | 348, a sub p sub e sub r sub p sub e sub n sub d sub i sub c sub u sub l s...
International Nuclear Information System (INIS)
Morais, M.C.; Lichtenthaele, R.; Arazi, A.; Hojman, D.; Cardona, M.A.; Fimiani, L.; Carnelli, P.F.; Marti, G.V.; Pacheco, A.J.; Martinez Heimann, D.; Negri, A.E.; Capurro, O.A.; Niello, Fernandez; Montero, P.
2011-01-01
Full text: The 16 O+ 12 C elastic scattering was investigated considering the effect of exchange of an alpha particle between projectile and target leading to the same nuclei of the entrance channel (elastic transfer). Angular distributions were analyzed in an energy range from 8.55 MeV to 56.57 MeV in the center of mass frame. The Coulomb barrier is around 11MeV for this system. Measurements of angular distributions of elastic and inelastic transfer reactions to states of the 16 O in the 16 O+ 12 C system were performed at the TANDAR Laboratory in Buenos Aires, using an 16 O beam of E lab = 46; 26 MeV. The transfer angular distributions were analyzed by DWBA using the computer code FRESCO. Those measurements provided the spectroscopic factors of 12 C + α → 16 O for the ground state and for J π = 2 + and J π = 1 - 16 O excited states, both just below the α-threshold at 7.16 MeV. The Asymptotic Normalization Coefficient (ANC) for the J π = 2 + state was obtained (1.05 ±0,13(10 5 fm -1/2 )) and used to calculate the reduced width of this state, with this value a R-matrix calculation was performed to determine the astrophysical S-factor in energies around the Gamow peak, S(E2)=37keVb. (author)
New quasibound states of the compound nucleus in α -particle capture by the nucleus
Maydanyuk, Sergei P.; Zhang, Peng-Ming; Zou, Li-Ping
2017-07-01
We generalize the theory of nuclear decay and capture of Gamow that is based on tunneling through the barrier and internal oscillations inside the nucleus. In our formalism an additional factor is obtained, which describes distribution of the wave function of the the α particle inside the nuclear region. We discover new most stable states (called quasibound states) of the compound nucleus (CN) formed during the capture of α particle by the nucleus. With a simple example, we explain why these states cannot appear in traditional calculations of the α capture cross sections based on monotonic penetrabilities of a barrier, but they appear in a complete description of the evolution of the CN. Our result is obtained by a complete description of the CN evolution, which has the advantages of (1) a clear picture of the formation of the CN and its disintegration, (2) a detailed quantum description of the CN, (3) tests of the calculated amplitudes based on quantum mechanics (not realized in other approaches), and (4) high accuracy of calculations (not achieved in other approaches). These peculiarities are shown with the capture reaction of α +44Ca . We predict quasibound energy levels and determine fusion probabilities for this reaction. The difference between our approach and theory of quasistationary states with complex energies applied for the α capture is also discussed. We show (1) that theory does not provide calculations for the cross section of α capture (according to modern models of the α capture), in contrast with our formalism, and (2) these two approaches describe different states of the α capture (for the same α -nucleus potential).
Journal of Education Finance, 2017
2017-01-01
In 2016, a group of school finance scholars and public school practitioners gathered in Jacksonville, Florida, for the National Education Finance Academy's annual conference to discuss, among an array of topics, the state of P-20 finance in all 50 states. At the roundtable discussion, 36 states were represented, and scholars representing 30 states…
Energy Technology Data Exchange (ETDEWEB)
Holland, D.M.P., E-mail: david.holland@stfc.ac.uk [Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom); Shaw, D.A. [Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom); Stener, M.; Decleva, P. [Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L. Giorgieri, I-34127 Trieste (Italy); Consorzio Interuniversitario Nazionale per la Scienze e Tecnologia dei Materiali, INSTM, Unità di Trieste (Italy); CNR-IOM, Trieste (Italy); Coriani, S. [Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L. Giorgieri, I-34127 Trieste (Italy); Consorzio Interuniversitario Nazionale per la Scienze e Tecnologia dei Materiali, INSTM, Unità di Trieste (Italy); Aarhus Institute of Advanced Studies, Aarhus University, 8000 Aarhus C (Denmark)
2016-09-30
Highlights: • The valence shell photoabsorption spectrum of s-triazine has been measured. • Electronic structure calculated with TDDFT and coupled cluster approaches. • Assignments proposed for Rydberg and valence states. • Mixing between Rydberg and valence states important. - Abstract: The absolute photoabsorption cross section of s-triazine has been measured between 4 and 40 eV, and is dominated by bands associated with valence states. Structure due to Rydberg excitations is both weak and irregular. Jahn-Teller interactions affect the vibronic structure observed in the Rydberg absorption bands due to excitation from the 1e″ or 6e′ orbitals. The interpretation of the experimental spectrum has been guided by transition energies and oscillator strengths, for Rydberg and valence states, calculated with the time-dependent version of density functional theory and with the coupled cluster linear response approach. The theoretical studies indicate that Rydberg/Rydberg and Rydberg/valence mixing is important.
The (n,p) reaction as a probe of nuclear structure
International Nuclear Information System (INIS)
Jackson, K.P.; Celler, A.
1988-08-01
An account is given of some results of studies of the (n,p) reaction on nuclear targets at TRIUMF. The (n,p) reaction, inducing spin flip transitions in isospin space, appears to exhibit a unique sensitivity to certain aspects of nuclear structure. The TRIUMF facility is the first to exploit the (n,p) reaction as a detailed probe of nuclear structure at energies above 65 MeV. In the (n,p) reaction Fermi transitions are absent, but there is a dramatic impact on Gamow-Teller and other collective transactions. Some nuclear transition matrix elements can be estimated on the basis of (n,p) measurements. Experiments have been carried out at TRIUMF on Li 6 , Fe 5 4, and Zr 9 0 targets. The calibration of the (n,p) reaction as a probe of the Gamow-Teller strength B + GT has been achieved for three targets. (L.L.) (45 refs., 10 figs.)
International Nuclear Information System (INIS)
Rykaczewski, Krzysztof Piotr; Karny, M.; Batist, L.; Banu, A.; Becker, F.; Blazhev, A.; Burkard, K.; Bruchle, W.; Doring, J.; Faestermann, T.; Gorska, M.; Grawe, H.; Janas, Z.; Jungclaus, A.; Kavatsyuk, M.; Kavatsyuk, O.; Kirchner, R.; La Commara, M.; Mandal, S.; Mazzocchi, C.; Miernik, K.; Mukha, I.; Muralithar, S.; Plettner, C.; Plochocki, A.; Roeckl, E.; Romoli, M.; Schadel, M.; Schmidt, K.; Schwengner, R.; Zylicz, J.
2005-01-01
The β-decay of 102 Sn was studied by using high-resolution germanium detectors as well as a Total Absorption Spectrometer (TAS). A decay scheme has been constructed based on the γ-γ coincidence data. The total experimental Gamow-Teller strength B GT exp of 102 Sn was deduced from the TAS data to be 4.2(9). A search for β-delayed γ-rays of 100 Sn decay remained unsuccessful. However, a Gamow-Teller hindrance factor h = 2.2(3), and a cross-section of about 3nb for the production of 100 Sn in fusion-evaporation reaction between 58 Ni beam and 50 Cr target have been estimated from the data on heavier tin isotopes. The estimated hindrance factor is similar to the values derived for lower shell nuclei
Action–angle variables, ladder operators and coherent states
International Nuclear Information System (INIS)
Campoamor-Stursberg, R.; Gadella, M.; Kuru, Ş.; Negro, J.
2012-01-01
This Letter is devoted to the building of coherent states from arguments based on classical action–angle variables. First, we show how these classical variables are associated to an algebraic structure in terms of Poisson brackets. In the quantum context these considerations are implemented by ladder type operators and a structure known as spectrum generating algebra. All this allows to generate coherent states and thereby the correspondence of classical–quantum properties by means of the aforementioned underlying structure. This approach is illustrated with the example of the one-dimensional Pöschl–Teller potential system. -- Highlights: ► We study the building of coherent states from classical action–angle variables arguments. ► The classical variables are associated to an algebraic structure in terms of Poisson brackets. ► In the quantum context these considerations are implemented by ladder type operators. ► All this allows to formulate coherent states and the correspondence of classical–quantum properties.
Quark-spin isospin sum rules and the Adler-Weisberger relation in nuclei
International Nuclear Information System (INIS)
Delorme, J.; Ericson, M.
1982-01-01
We use a quark model to extend the classical Gamow-Teller sum rule for the difference of the β - and β + strengths to excitations of the nucleon (mainly the Δ isobar). A schematic model illustrates the realization of the new sum rule when a particle-hole force is introduced. We discuss the connection of our result with the model-independent Adler-Weisberger sum rule. (orig.)
International Nuclear Information System (INIS)
Horowitz, C.J.; Macfarlane, M.H.; Serot, B.D.
1989-01-01
In this period covered by this report (April 1, 1988 to March 31, 1989), work focused on six main areas: Relativistic Theories of Nuclear Structure and Saturation; Relativistic Descriptions of Proton- Nucleus and Electron-Nucleus Scattering; Nonrelativistic Theory of Nucleon-Nucleus Reactions; Gamow-Teller Excitations in Nuclear Charge- Exchange Reactions; Relativistic Many-Body Theory at Finite Temperature and Density and Relativistic Atomic Physics of High Z Atoms. Results and publications in these areas are summarized in this report
Measurement of Angular Correlations in the Decay of Polarized Neutrons
DEFF Research Database (Denmark)
Christensen, Carl Jørgen; Krohn, V.E.; Ringo, G.R.
1970-01-01
The electron-momentum-neutron-spin correlation coefficient was found to be A=-0.115±0.008, and the antineutrino-momentum-neutron-spin correlation coefficient was found to be B=1.00±0.05. The value of A leads to |GA/GV|=1.26±0.02 for the ratio of Gamow-Teller-to-Fermi coupling constants in β decay...
Beta-delayed particle decay of 17Ne
International Nuclear Information System (INIS)
Morton, A.C.; Chow, J.C.; King, J.D.; Boyd, R.N.; Bateman, N.P.T.; Buchmann, L.; D'Auria, J.M.; Davinson, T.; Dombsky, M.; Galster, W.; Gete, E.; Giesen, U.; Iliadis, C.; Jackson, K.P.; Powell, J.; Roy, G.; Shotter, A.
2002-01-01
The β-delayed particle decay of 17 Ne has been studied via proton-γ coincidences, time-of-flight measurements and the ''ratio-cut technique'', allowing cleanly-separated proton and α-particle spectra to be obtained. A complete set of proton and α branching ratios for the decay of 14 excited states in 17 F to the ground and excited states of 16 O and 13 N has been determined and branching ratios for the β decay of 17 Ne to these states have been deduced. From the branching ratios, f A t values and reduced Gamow-Teller matrix elements were calculated; no indication of isospin mixing in the isobaric analog state in 17 F was observed. From the measurement of proton-γ angular correlations, combined with the selection rules for an allowed β decay, we obtain J π =((1)/(2)) - for states at 8.436 and 9.450 MeV and ((3)/(2)) - for the state at 10.030 MeV in 17 F. Probabilities for the β-delayed pα decay to 12 C through the tails of the subthreshold 7.117 and 6.917 MeV states in 16 O have been calculated and the feasibility of using such decays to provide information about the rates for the E1 and E2 components of the 12 C(α,γ) 16 O reaction is discussed
Nucleon charge-exchange reactions at intermediate energy
Energy Technology Data Exchange (ETDEWEB)
Alford, W.P. [Western Ontario Univ., London, ON (Canada). Dept. of Physics]|[TRIUMF, Vancouver, BC (Canada); Spicer, B.M. [Melbourne Univ., Parkville, VIC (Australia). School of Physics
1997-12-31
An historical review of the development of ideas pertaining to Gamow-Teller giant resonances is given, and a description of the emergence of techniques for the study of charge exchange reactions - particularly the technical advances which yielded the recent volume of new date. The present status of charge exchange reactions is reviewed and assessed. Evidence is presented from the {sup 14}C(p,n) reaction for the dominance of the spin-isospin component of the nucleon-nucleon interaction in intermediate energy reactions. In (p,n) reactions the Gamow-Teller giant resonance dominates the spectra, with higher multipoles contributing. By contrast, in (n,p) reactions in the heavier nuclei, the Gamow-Teller transitions are substantially Pauli-blocked and the spin dipole resonance dominates, with contributions from higher multipoles. Discussions of the multipole decomposition process, used to obtain from the data the contributions of the different multipoles, and the contributions of the multipoles, are given. 226 refs., 19 figs.
Experimental study of radiative pion capture on 13C, 20Ne, 90Zr, 19F and 12C
International Nuclear Information System (INIS)
Martoff, C.J.
1980-11-01
Photon spectra for 50 13 C, 19 F, 20 Ne, and 90 Zr. The e + e - pair spectrometer system used has resolution 850 keV fwhm and photon detection efficiency 5 x 10 -6 . The total radiative capture branching ratios measured are 13 C (1.66 +- 0.25)%, 19 F (2.40 +- 0.48)%, 20 Ne (1.60 +- 0.24)%, and 90 Zr (2.1 +- 0.5)%. The partial radiative capture branching ratios to four bound states and two resonances in 20 F, and two bound states and three resonances in 13 B have also been measured. The branching ratio for 13 C(π - ,γ) 13 B g.s. is (6.1 +- 1.2) x 10 -4 . Comparison of this result with the beta decay rate of 13 B shows that (84 +- 16)% of the pion capture amplitude is accounted for by the Gamow-Teller matrix element. Further analysis suggests that much of the remaining strength is E2. The measured branching ratios to resonant states in 13 C(π - ,γ) 13 B are shown to be in agreement with detailed shell model calculations. The total single-particle strength in these transitions is shown to be approximately half as large as that of the T = 3/2 part of the E1 photoresonance (the Giant Dipole Resonance) in 13 C. The branching ratio for 20 Ne(π - ,γ) 20 F (T = 1, J/sup π/ = 1 + , E/sub x/ = 1.06 MeV) is 0.91 +- 0.52).10 -4 . Comparison with the electroexcitation of the analog giant M1 state in 20 Ne (11.24 MeV) shows that the M1 transition amplitude is less than (46 +- 14)% Gamow-Teller. This result is in agreement with detailed shell model calculations of the M1 transition. The photon spectrum for radiative pion capture from flight (reaction 12 C(π + T = 44 MeV, γ at 90 0 )) has been measured. 13 figures, 12 tables
Orbital physics in sulfur spinels: ordered, liquid and glassy ground states
International Nuclear Information System (INIS)
Buettgen, N; Hemberger, J; Fritsch, V; Krimmel, A; Muecksch, M; Nidda, H-A Krug von; Lunkenheimer, P; Fichtl, R; Tsurkan, V; Loidl, A
2004-01-01
Measurements of magnetization M(T, H), heat capacity C(T), NMR lineshift K(T) and linewidth Δ(T), neutron scattering S(Q, ω, T) and broadband dielectric spectroscopy ε(ω, T) provide experimental evidence of the different orbital ground states in the cubic sulfur spinels under investigation. In all compounds, the tetrahedrally coordinated Jahn-Teller ions Fe 2+ are characterized by a degeneracy of the orbital degrees of freedom. Particularly, we found a long-range orbital ordering in polycrystalline (PC) FeCr 2 S 4 , and a glassy freezing of the orbital degrees of freedom in FeCr 2 S 4 (single crystals) (SCs). In contrast, FeSc 2 S 4 belongs to the rare class of spin-orbital liquids, where quantum fluctuations accompanying the glassy freezing of the orbitals suppress long-range magnetic order
Directory of Open Access Journals (Sweden)
Hyewon Kong
2018-06-01
Full Text Available Employees’ emotional-labor strategies, experienced affects, and emotional exhaustion in the workplace may vary over time within individuals, even within the same day. However, previous studies on these relationships have not highlighted their dynamic properties of these relationships. In addition, although the effects of surface and deep acting on emotional exhaustion have been investigated in emotional-labor research, empirical studies on these relationships still report mixed results. Thus, we suggest that moderators may affect the relationship between emotional labor and emotional exhaustion. Also, this study examines the relationship between emotional labor and emotional exhaustion within individuals by repeated measurements, and verifies the mediating effect of a negative affect state. Finally, our study confirms the moderating effects that affective commitment has on the relationship between emotional labor and emotional exhaustion. Data was collected from tellers who had a high degree of interaction with clients at banks based in South Korea. A total of 56 tellers participated in the survey and responded for five working days. A total of 616 data entries were collected from the 56 respondents. We used a hierarchical linear model (HLM to examine our hypothesis. The results showed that surface-acting emotional labor increases emotional exhaustion; furthermore, the relationship between surface acting emotional labor and emotional exhaustion is mediated by a negative affect state within individuals. In addition, this study verified that affective commitment buffers the negative effects that surface acting emotional labor has on emotional exhaustion. These results suggest that emotional labor is a dynamic process within individuals, and that emotional exhaustion caused by emotional labor differs among individuals, and is dependent upon factors such as the individual’s level of affective commitment.
African Journals Online (AJOL)
Dr. Miles R. Cone
The state and society are mutual symbionts as far as their political, economic and social relationships .... consequences have played a role in the African state's deviation from the 'strong state' ideal. .... International Olympic Committee (IOC).
Spin states of reduced fullerenes (C60 and C120O) by CW and pulsed EPR
International Nuclear Information System (INIS)
Boas, J.F.; Drew, S.C.; Pilbrow, J.R.; Boyd, P.D.W.; Paul, P.; Reed, C.A.; Sun, D.
2003-01-01
Full text: The ESTN (Electron Spin Transient Nutation) EPR (Electron Paramagnetic Resonance) experiments reported at Wagga 2002 showed that the spin states of the reduced fullerenes C 120 O (2-), C 120 O (3-) and C 120 O (4-) were S = 1, S = 1/2 and S = 1 respectively. Further experiments using CW (Continuous Wave) EPR have confirmed the results of Paul et al. and have now shown that these states are the ground states of these anions. In the case of C 60 (3-), the recent CW and ESTN EPR experiments have shown that the electronic ground state of this anion is S = 1/2. The observation of ground states of low multiplicity for these anions is contrary to expectations based on MO calculations and the application of Hund's rules. A series of CW EPR experiments on C 60 (3-) have shown that some previous results may need to be re-interpreted. This arises from the delineation of the effects of microwave power, modulation amplitude and frequency, sample temperature and freezing rate on the EPR spectrum which is the combination of a broad line, attributed to C 60 (3-), and a 'spike' attributed to C 120 O impurities and other oxygen related species. Our results cast doubt on the existence of Jahn-Teller effects at low temperatures and of a low-lying spin quartet excited state
Spin-state blockade in Te6+-substituted electron-doped LaCoO3
Tomiyasu, Keisuke; Koyama, Shun-Ichi; Watahiki, Masanori; Sato, Mika; Nishihara, Kazuki; Onodera, Mitsugi; Iwasa, Kazuaki; Nojima, Tsutomu; Yamasaki, Yuuichi; Nakao, Hironori; Murakami, Youichi
2015-03-01
Perovskite-type LaCoO3 (Co3+: d6) is a rare inorganic material with sensitive and characteristic responses among low, intermediate, and high spin states. For example, in insulating nonmagnetic low-spin states below about 20 K, light hole doping (Ni substitution) induces much larger magnetization than expected; over net 10μB/hole (5μB/Ni) for 1μB/hole (1μB/Ni), in which the nearly isolated dopants locally change the surrounding Co low-spin states to magnetic ones and form spin molecules with larger total spin. Further, the former is isotropic, whereas the latter exhibits characteristic anisotropy probably because of Jahn-Teller distortion. In contrast, for electron doping, relatively insensitive spin-state responses were reported, as in LaCo(Ti4+) O3, but are not clarified, and are somewhat controversial. Here, we present macroscopic measurement data of another electron-doped system LaCo(Te6+) O3 and discuss the spin-state responses. This study was financially supported by Grants-in-Aid for Young Scientists (B) (No. 22740209 and 26800174) from the MEXT of Japan.
Electron localization, polarons and clustered states in manganites
International Nuclear Information System (INIS)
Mannella, N.
2004-01-01
Full text: A recent multi-spectroscopic study of prototypical colossal magnetoresistance (CMR) compounds La 1-x Sr x MnO 3 (LSMO, x = 0.3, 0.4) using photoemission (PE), x-ray absorption (XAS), x-ray emission (XES) and extended x-ray absorption e structure (EXAFS) has exposed a dramatic change in the electronic structure on crossing the ferromagnetic-to-paramagnetic transition temperature (T C ). In particular, this investigation revealed an increase of the Mn magnetic moment by ca. 1 Bohr magneton and charge transfer to the Mn atom on crossing T C concomitant with the presence of Jahn-Teller distortions, thus providing direct evidence of lattice polaron formation. These results thus challenge the belief of some authors that the LSMO compounds are canonical double-exchange (DE) systems in which polaron formation is unimportant, and thus help to unify the theoretical description of the CMR oxides. The relationship of these data to other recent work suggesting electron localization, polarons and phase separation, along with additional measurements of magnetic susceptibility indicating the formation of ferromagnetic clusters in the metallic paramagnetic state above T C will be discussed
Is neutrinoless double beta decay suppressed
International Nuclear Information System (INIS)
Tomoda, T.
1989-01-01
Much effort has been devoted to the study of nuclear double beta decay, since the observation of a neutrinoless double beta (OνΒΒ) decay would be clear evidence that the electron neutrino is a Majorana particle. The OνΒΒ decay is caused by a finite Majorana neutrino mass and/or an admixture of right-handed leptonic currents. In order to relate these quantities to OνΒΒ decay rates, we need nuclear matrix elements, which are model dependent. One of the possibilities of testing nuclear models employed in such analysis is to calculate the experimentally known rates of ΒΒ decay with emission of two neutrinos (2νΒΒ decay) which occurs independently of the nature of the neutrino. There was a long-standing difficulty in such attempts that the calculated 2νΒΒ decay rates turned out to be always too large by one to two orders of magnitude. Trying to overcome such difficulty, Klapdor and Grotz as well as Vogel and Zirnbauer showed in their calculation using schematic effective interactions such that 2νΒΒ decay rates can get reduced considerably due to the nuclear ground state correlations. This paper reports that the suppression is ascribed to that of the virtual Gamow-Teller transitions from the excited 1 + states of the intermediate odd-odd -even nucleus
Low-spin structure of 51,35,86Br and 50,36,86Kr nuclei: The role of the g7 /2 neutron orbital
Urban, W.; Sieja, K.; Materna, T.; Czerwiński, M.; Rząca-Urban, T.; Blanc, A.; Jentschel, M.; Mutti, P.; Köster, U.; Soldner, T.; de France, G.; Simpson, G. S.; Ur, C. A.; Bernards, C.; Fransen, C.; Jolie, J.; Regis, J.-M.; Thomas, T.; Warr, N.
2016-10-01
Low-spin excited levels in 51,35,86Br and 50,36,86Kr, populated following β- decay and the neutron-induced fission of 235U, were measured using the Lohengrin fission-fragment separator and the EXILL array of Ge detectors at the PF1B cold-neutron facility of the Institute Laue-Langevin Grenoble. Improved populations of excited levels in 86Br remove inconsistencies existing in the literature on this nucleus. Directional-linear-polarization correlations, analyzed using newly developed formulas, as well as precise angular correlations allowed the unique 1- and 2- spin and parity assignments to the ground state of 86Br and the 4016.3-keV level in 86Kr, respectively. Based on these results we propose that the Gamow-Teller β- decays of 86Se and 86Br involve the ν g7 /2→π g9 /2 transition in addition to the ν p3 /2→π p3 /2 transition proposed earlier. In 86Kr we have identified 11+, 23+, and 31+ levels, analogous to the mixed-symmetry states in 94Mo, which in 86Kr are from proton excitations, only. Large-scale, shell-model calculations with refined interactions reproduce well excitations in 86Br and 86Kr and support our interpretations.
Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge
Brown, B A; Horoi, M
2015-01-01
The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...
International Nuclear Information System (INIS)
Suzuki, T.; Sagawa, H.
2000-01-01
Complete text of publication follows. Spin and isospin modes in nuclei are investigated. We discuss some of the following topics. 1. Spin-dipole excitations in 12 C and 16 O are studied (1). Effects of tensor and spin-orbit interactions on the distribution of the strengths are investigated, and neutral current neutrino scattering cross sections in 16 O are obtained for heavy-flavor neutrinos from the supernovae. 2. Gamow-Teller (GT) and spin-dipole (SD) modes in 208 Bi are investigated. Quenching and fragmentation of the GT strength are discussed (2). SD excitations and electric dipole (E1) transitions between the GT and SD states are studied (3). Calculated E1 strengths are compared with the sum rule values obtained within the 1p-1h and 1p-1h + 2p-2h configuration spaces. 3. Coulomb displacement energy (CDE) of the IAS of 14 Be is calculated, and the effects of the halo on the CDE and the configuration of the halo state are investigated. 4. Spreading width of IAS and isospin dependence of the width are investigated (4). Our formula for the width explains very well the observed isospin dependence (5). (author)
Isospin Symmetry of Transitions Probed by Weak and Strong Interactions
Roeckl, E
2002-01-01
Under the assumption that isospin is a good quantum number, isospin symmetry is expected for the transitions from the ground states of the pair of T = 1, T$_{z}$ = $\\pm$ 1 nuclei to excited states of the T = 0 nucleus situated in between the pair. In order to study the isospin symmetry of these transitions, we propose to perform an accurate comparison of Gamow-Teller (GT) transitions for the A = 58 system. This system is the heaviest for which such a comparison is possible. The $^{58}$Ni(T$_{z}$ = 1 ) $\\rightarrow^{58}$Cu(T$_{z}$ = 0 ) GT transitions are presently studied by using high-resolution charge exchange reaction at RNCP Osaka, while those of $^{58}$Zn(T$_{z}$ = -1) $\\rightarrow^{58}$Cu will be investigated in the $\\beta$-decay study at ISOLDE. Due to the large $Q\\scriptstyle_\\textrm{EC}$-value of $^{58}$Zn, GT transitions can be observed up to high excitation energies in $^{58}$Cu. In order to reach this goal, it is proposed to measure $\\beta$-delayed protons and $\\gamma$-rays by using a dedicated de...
Elucidation of impact of tensor force on the β decay of magic and semi-magic nuclei
International Nuclear Information System (INIS)
Minato, Futoshi
2016-01-01
The authors theoretically examined the β decay of neutron-rich nuclei with a magic number and semi-magic number, using a proton-neutron random phase approximation method. The tensor force previously believed to have a significant impact on the development of the structure of unstable nuclei was found to potentially have an impact on β decay, too. This paper introduces how β decay half-life is reproduced by the tensor force, with a focus on its microscopic mechanism. It was found that the tensor force plays an important role in the β decay of 34 Si, 68,78 Ni, and 132 Sn. Although the calculation of Gamow-Teller transition (GT transition) leaves room for theoretical confirmation, it is clear that the tensor force has a large impact on the 1+ excited state of GT transition. Therefore, for the reliable prediction of the β decay half-life of unknown nuclei, it is necessary to take into account the impact of tensor force. β decay, along with the mass, radius, and excited state, is one of the characteristics possessed by unstable nuclei, and it is important to increase the knowledge of nuclear structure theory so as to be able to systematically predict the probability of β decay. (A.O.)
The Structure of the Heavy Calcium Isotopes and the Effective Interaction in the sd-fp Shell
Dorvaux, O; Nowacki, F; Courtin, S; Marechal, F; Siiskonen, T M; Perrot, F; Pietri, S B
2002-01-01
Nuclei with 40 $<$ A $<$ 56, near the stability line, are very well described in the frame of the shell model. However, when the number of neutrons increases, the situation becomes more complex which explains why the interaction can be found very dissimilar within different calculations. Heavy Ca isotopes, because of the simplicity of their wave-functions, correspond to the optimal choice to fix unambiguously the interaction in this mass region.\\\\ It is proposed to measure the $\\beta$-decay of $^{51, 52, 53}$K with the help of an utmost performing neutron (TONNERRE array) and $\\gamma$- (Miniball clusters) detection, allowing efficient coincidence measurements. This will allow the lowest lying Gamow-Teller states to be located in $^{51, 52, 53}$Ca, and the still unknown properties of natural parity states to be investigated. The awaited results should allow to settle the n-n interaction in the fp shell and the Gnp matrix accross the sd and fp shells, one step farther from stability, by comparison with fu...
U.S. Department of Health & Human Services — Payment measures – state data. This data set includes state-level data for the payment measures associated with an episode of care for heart attack, heart failure,...
Supersqueezed states from squeezed states
International Nuclear Information System (INIS)
Nieto, M.M.
1992-01-01
Using super-Baker-Campbell-Hausdorff relations on the elements of the supergroup OSP(2/2), we derive the supersqueeze operator and the supersqueezed states, which are the supersymmetric generalization of the squeezed states of the harmonic oscillator
Lim, Edward C
1974-01-01
Excited States, Volume I reviews radiationless transitions, phosphorescence microwave double resonance through optical spectra in molecular solids, dipole moments in excited states, luminescence of polar molecules, and the problem of interstate interaction in aromatic carbonyl compounds. The book discusses the molecular electronic radiationless transitions; the double resonance techniques and the relaxation mechanisms involving the lowest triplet state of aromatic compounds; as well as the optical spectra and relaxation in molecular solids. The text also describes dipole moments and polarizab
International Nuclear Information System (INIS)
Raduta, A.A.; Delion, D.S.; Faessler, A.
1997-01-01
The suppression mechanism of the Gamow-Teller double beta decay amplitude M GT is studied using a many body Hamiltonian which describes a composite system of protons and neutrons moving in a projected spherical single particle basis. Alike nucleons interact through pairing while protons and neutrons by a separable dipole-dipole force both in the particle-hole (ph) and particle-particle (pp) channels. The spin-flip and non-spin-flip components of the QRPA phonons have a differents contribution to the M GT values. The relative magnitudes and phases depend both on the strength of the particle-particle interaction (g pp ) and on the nuclear deformation. The deformation yields a fragmentation of the M GT value on one hand and washes out the separation of states of pure spin-flip and non-spin-flip structures. Due to this effect M GT has only one fragmented resonance structure in the low part of the spectrum. (orig.)
Interplay of quasiparticle-vibration coupling and pairing correlations on β-decay half-lives
Niu, Y. F.; Niu, Z. M.; Colò, G.; Vigezzi, E.
2018-05-01
The nuclear β-decay half-lives of Ni and Sn isotopes, around the closed shell nuclei 78Ni and 132Sn, are investigated by computing the distribution of the Gamow-Teller strength using the Quasiparticle Random Phase Approximation (QRPA) with quasiparticle-vibration coupling (QPVC), based on ground-state properties obtained by Hartree-Fock-Bogoliubov (HFB) calculations. We employ the effective interaction SkM* and a zero-range effective pairing force. The half-lives are strongly reduced by including the QPVC. We study in detail the effects of isovector (IV) and isoscalar (IS) pairing. Increasing the IV strength tends to increase the lifetime for nuclei in the proximity of, but lighter than, the closed-shell ones in QRPA calculations, while the effect is significantly reduced by taking into account the QPVC. On the contrary, the IS pairing mainly plays a role for nuclei after the shell closure. Increasing its strength decreases the half-lives, and the effect at QRPA and QRPA+QPVC level is comparable. The effect of IS pairing is particularly pronounced in the case of the Sn isotopes, where it turns out to be instrumental to obtain good agreement with experimental data.
The nuclear spin response to intermediate energy protons and deuterons at low momentum transfer
International Nuclear Information System (INIS)
Baker, F.T.; Djalali, C.; Glashausser, C.; Lenske, H.; Love, W.G.; Tomasi-Gustafsson, E.; Wambach, J.
1997-01-01
Measurements of polarization transfer in the inelastic scattering of intermediate energy protons and deuterons have yielded a wealth of data on the spin response of nuclei. This work complements the well-known studies of Gamow-Teller strength in charge-exchange reactions. The emphasis here is on a consistent determination of the S=1, T=0 response, practical only with deuterons, and on the proper separation of S=0 and S=1 strength in proton spectra for appropriate comparison with sum rules. We concentrate on two nuclei, 40 Ca and 12 C, at momentum transfers below about 1 fm -1 and on excitations up to about 50 MeV. The continuum second random phase approximation provides the primary theoretical tool for calculating and interpreting the response in terms of properties of the nucleon-nucleon force inside the nuclear medium. The reaction mechanism is described by the DWIA, applied here to continuum proton scattering almost as rigorously as it is usually applied to low energy excitations. A new DWIA formalism for the description of spin observables in deuteron scattering is used. Comparison of the proton and deuteron data with each other and with RPA/DWIA calculations yields interesting insights into the current state of understanding of collectivity and the nuclear spin response. (orig.)
International Nuclear Information System (INIS)
Hannen, V.M.; Van den Berg, A.M.; Bieber, R.K.; Harakeh, M.N.; De Huu, M.A.; Kruesemann, B.A.M.; Van der Werf, S.Y.; Woertche, H.J.; Amos, K.; Deb, P.K.; Ellinghaus, F.; Frekers, D.; Rakers, S.; Schmidt, R.; Hagemann, M.
2001-01-01
Cross sections and analyzing powers for the 11 B(p.p') reaction have been measured using a 150 MeV polarized proton beam from the AGOR cyclotron at KVI. For the stronger inelastic transitions, also spin-flip probabilities have been extracted. A fully microscopic distorted-wave analysis of the elastic and inelastic data has been made, using density-dependent effective interactions and input from shell-model calculations in a complete (0+2) ℎω model space for normal parity transitions and in a 1 ℎω model space for non-normal parity transitions. With the help of these model calculations spin-isovector M1 strengths for the negative-parity states at excitation energies of 2.125 MeV (J π = 1/2 - ), 4.445 MeV (J π 5/2 - ), 5.020 MeV (J π = 3/2 - ) and 8.920 MeV (J π 5/2 - ) have been extracted and compared to known Gamow-Teller strengths for the analog transitions to 11 C
High-precision branching-ratio measurement for the superallowed β+ emitter 74Rb
Dunlop, R.; Ball, G. C.; Leslie, J. R.; Svensson, C. E.; Towner, I. S.; Andreoiu, C.; Chagnon-Lessard, S.; Chester, A.; Cross, D. S.; Finlay, P.; Garnsworthy, A. B.; Garrett, P. E.; Glister, J.; Hackman, G.; Hadinia, B.; Leach, K. G.; Rand, E. T.; Starosta, K.; Tardiff, E. R.; Triambak, S.; Williams, S. J.; Wong, J.; Yates, S. W.; Zganjar, E. F.
2013-10-01
A high-precision branching-ratio measurement for the superallowed β+ decay of 74Rb was performed at the TRIUMF Isotope Separator and Accelerator (ISAC) radioactive ion-beam facility. The scintillating electron-positron tagging array (SCEPTAR), composed of 10 thin plastic scintillators, was used to detect the emitted β particles; the 8π spectrometer, an array of 20 Compton-suppressed HPGe detectors, was used for detecting γ rays that were emitted following Gamow-Teller and nonanalog Fermi β+ decays of 74Rb; and the Pentagonal Array of Conversion Electron Spectrometers (PACES), an array of 5 Si(Li) detectors, was employed for measuring β-delayed conversion electrons. Twenty-three excited states were identified in 74Kr following 8.241(4)×108 detected 74Rb β decays. A total of 58 γ-ray and electron transitions were placed in the decay scheme, allowing the superallowed branching ratio to be determined as B0=99.545(31)%. Combined with previous half-life and Q-value measurements, the superallowed branching ratio measured in this work leads to a superallowed ft value of 3082.8(65) s. Comparisons between this superallowed ft value and the world-average-corrected Ft¯ value, as well as the nonanalog Fermi branching ratios determined in this work, provide guidance for theoretical models of the isospin-symmetry-breaking corrections in this mass region.
Improvements of mass formula and β-decay gross theory
International Nuclear Information System (INIS)
Tachibana, Takahiro
1987-01-01
The nuclear mass greatly decreases when the number of protons Z and neutrons N is simultaneously equal to a magic number (mutual support of magicities). The mass also tends to decrease due to deformation as both N and Z are away from the magic numbers (mutual support of deformations). These two effects are introduced to a nuclear mass formula containing a constant-type shell term to derive a new formula. The mass excess is expressed by a sum of three parts, i.e. gross part, even-odd part and shell part. The gross part, which represents the general nature, consists of two rest mass terms and a coulomb term. The even-odd part is of a typical form with a correction term. The shell part consists of a proton shell term, neutron shell term, third term expressing the two mutual support effects, and fourth term representing a decrease in coulomb energy due to deformation of the nucleus. The improvements made in the β-decay gross theory are associated with the single particle intensity function D 0 GT (E,ε). They are intended for: (1) reproducing the peak that accounts for about a half of the Gamow-Teller intensity, which has recently been found in (p,n) reactions at energies above the isobaric analogue state and (2) explaining the other half by an exponential-type D 0 GT (E,ε). (Nogami, K.)
Relativistic mean field theory for unstable nuclei
International Nuclear Information System (INIS)
Toki, Hiroshi
2000-01-01
We discuss the properties of unstable nuclei in the framework of the relativistic mean field (RMF) theory. We take the RMF theory as a phenomenological theory with several parameters, whose form is constrained by the successful microscopic theory (RBHF), and whose values are extracted from the experimental values of unstable nuclei. We find the outcome with the newly obtained parameter sets (TM1 and TMA) is promising in comparison with various experimental data. We calculate systematically the ground state properties of even-even nuclei up to the drip lines; about 2000 nuclei. We find that the neutron magic shells (N=82, 128) at the standard magic numbers stay at the same numbers even far from the stability line and hence provide the feature of the r-process nuclei. However, many proton magic numbers disappear at the neutron numbers far away from the magic numbers due to the deformations. We discuss how to describe giant resonances for the case of the non-linear coupling terms for the sigma and omega mesons in the relativistic RPA. We mention also the importance of the relativistic effect on the spin observables as the Gamow-Teller strength and the longitudinal and transverse spin responses. (author)
Observables in muon capture on 23Na and the effective weak couplings ga and gp
International Nuclear Information System (INIS)
Johnson, B.L.; Gorringe, T.P.; Armstrong, D.S.; Bauer, J.; Hasinoff, M.D.; Kovash, M.A.; Measday, D.F.; Moftah, B.A.; Porter, R.; Wright, D.H.
1996-01-01
We report measurements of capture rates and hyperfine dependences in muon capture on 23 Na to various states in Ne and F isotopes. We also report comparisons of the capture rates and hyperfine dependences for six 23 Na → 23 Ne transitions with the 1s-0d shell model with the empirical effective interaction of Brown and Wildenthal and the realistic effective interaction of Kuo and Brown. Fits to the data with the Brown and Wildenthal interaction yield an effective coupling g a = -1.01 ± 0.07 and an effective coupling ratio g p /g a = 6.5 ± 2.4. The value of g a is consistent with values of g a extracted from β + /β - decay and (p,n)/(n,p) charge exchange data, and the value of g p /g a is consistent with the predictions of PCAC and pion-pole dominance. We evaluate the nuclear model dependence of these values of g a and g p /g a and examine the role of the Gamow-Teller and other matrix elements in the 23 Na → 23 Ne transitions. copyright 1996 The American Physical Society
Temperature dependence of pair correlations in nuclei in the iron region
International Nuclear Information System (INIS)
Langanke, K.; Dean, D.J.; Oak Ridge National Lab., TN; Radha, P.B.; Koonin, S.E.
1996-01-01
We use the shell-model Monte Carlo approach to study thermal properties and pair correlations in 54,56,58 Fe and in 56 Cr. The calculations are performed with the modified Kuo-Brown interaction in the complete 1p0f model space. We find generally that the proton-proton and neutron-neutron J=0 pairing correlations, which dominate the ground-state properties of even-even nuclei, vanish at temperatures around 1 MeV. This pairing phase transition is accompanied by a rapid increase in the moment of inertia and a partial unquenching of the M1 strength. We find that the M1 strength totally unquenches at higher temperatures, related to the vanishing of isoscalar proton-neutron correlations, which persist to higher temperatures than the pairing between like nucleons. The Gamow-Teller strength is also correlated to the isoscalar proton-neutron pairing and hence also unquenches at a temperature larger than that of the pairing phase transition. (orig.)
Measurement of the resonance at E(lab)=1422 keV in 36Ar(p, γ)37K
International Nuclear Information System (INIS)
Iliadis, C.; Meissner, J.; Wiescher, M.
1993-01-01
Measurements of Gamow-Teller (GT) transition strengths provide information both about the nature of the weak interaction and about the structure of nuclear wave functions. A recent measurement of the Β-delayed proton decay of 37 Ca resulted in a GT strength distribution which disagreed strongly with the results from a forward angle 37 Cl(p,n) 37 Ar experiment. Both results should be identical as long as isospin is a good quantum number. The largest disagreements between the two experiments were found at excitation energies below the isobaric analog state at 5.0 MeV. It has been noted that the discrepancies could be removed if the level at 3.24 MeV in 37 K predominantly decays through the γ-channel rather than the proton channel. Therefore, we have measured the corresponding resonance at 1.42 MeV in the reaction 36 Ar(p,γ) 37 K. The implications with regard to the GT distribution below the IAS will be discussed
Nuclear spin-isospin excitations from covariant quasiparticle-vibration coupling
Robin, Caroline; Litvinova, Elena
2016-09-01
Methods based on the relativistic Lagrangian of quantum hadrodynamics and nuclear field theory provide a consistent framework for the description of nuclear excitations, naturally connecting the high- and medium-energy scales of mesons to the low-energy domain of nucleonic collective motion. Applied in the neutral channel, this approach has been quite successful in describing the overall transition strength up to high excitation energies, as well as fine details of the low-lying distribution. Recently, this method has been extended to the description of spin-isospin excitations in open-shell nuclei. In the charge-exchange channel, the coupling between nucleons and collective vibrations generates a time-dependent proton-neutron effective interaction, in addition to the static pion and rho-meson exchange, and introduces complex configurations that induce fragmentation and spreading of the resonances. Such effects have a great impact on the quenching of the strength and on the computing of weak reaction rates that are needed for astrophysics modeling. Gamow-Teller transitions in medium-mass nuclei and associated beta-decay half-lives will be presented. Further developments aiming to include additional ground-state correlations will also be discussed. This work is supported by US-NSF Grants PHY-1404343 and PHY-1204486.
Weak-interaction rates in stellar conditions
Sarriguren, Pedro
2018-05-01
Weak-interaction rates, including β-decay and electron captures, are studied in several mass regions at various densities and temperatures of astrophysical interest. In particular, we study odd-A nuclei in the pf-shell region, which are involved in presupernova formations. Weak rates are relevant to understand the late stages of the stellar evolution, as well as the nucleosynthesis of heavy nuclei. The nuclear structure involved in the weak processes is studied within a quasiparticle proton-neutron random-phase approximation with residual interactions in both particle-hole and particle-particle channels on top of a deformed Skyrme Hartree-Fock mean field with pairing correlations. First, the energy distributions of the Gamow-Teller strength are discussed and compared with the available experimental information, measured under terrestrial conditions from charge-exchange reactions. Then, the sensitivity of the weak-interaction rates to both astrophysical densities and temperatures is studied. Special attention is paid to the relative contribution to these rates of thermally populated excited states in the decaying nucleus and to the electron captures from the degenerate electron plasma.
Progress in research, April 1, 1992--March 31, 1993, Texas A and M University Cyclotron Institute
Energy Technology Data Exchange (ETDEWEB)
NONE
1993-07-01
This Institute annual report for the period 1 April 1992--31 March 1993 covers a period which has seen the initial runs of three new spectrometers which constitute a major portion of the new detection capabilities developed for this facility. These devices are the Proton Spectrometer (PSP), the Mass Achromat Recoil Mass Spectrometer (MARS), and the Multipole dipole Multipole (MDM) Particle Spectrometer. These devices are now available to pursue the studies of Gamow Teller states, reactions of astrophysical interest, and giant resonance studies for which they were constructed, as well as for other experiments. A beam analysis system which will deliver high resolution beams to the MDM spectrometer is currently under construction. With the completion of these spectrometer projects, the facility emphasis is now focused on the development of the full capabilities of the K500 cyclotron and on the research program. During the report period, the ECR-K500 cyclotron combination operated 5,849 hours. Theoretical work reported in this document ranges from nuclear structure calculations using the IBM-2 model to calculations of kaon production and the in-medium properties of the rho and phi mesons, the latter as a probe of the QCD phase transition. Nuclear dynamics and exotic shapes and fragmentation modes of hot nuclei are also addressed. In atomic physics, new measurements of x-ray emission from highly ionized ions, of molecular dissociation and of surface interactions are reported.
Progress in research, April 1, 1992 - March 31, 1993, Texas A and M University Cyclotron Institute
International Nuclear Information System (INIS)
1993-07-01
This Institute annual report for the period 1 April 1992--31 March 1993 covers a period which has seen the initial runs of three new spectrometers which constitute a major portion of the new detection capabilities developed for this facility. These devices are the Proton Spectrometer (PSP), the Mass Achromat Recoil Mass Spectrometer (MARS), and the Multipole dipole Multipole (MDM) Particle Spectrometer. These devices are now available to pursue the studies of Gamow Teller states, reactions of astrophysical interest, and giant resonance studies for which they were constructed, as well as for other experiments. A beam analysis system which will deliver high resolution beams to the MDM spectrometer is currently under construction. With the completion of these spectrometer projects, the facility emphasis is now focused on the development of the full capabilities of the K500 cyclotron and on the research program. During the report period, the ECR-K500 cyclotron combination operated 5,849 hours. Theoretical work reported in this document ranges from nuclear structure calculations using the IBM-2 model to calculations of kaon production and the in-medium properties of the rho and phi mesons, the latter as a probe of the QCD phase transition. Nuclear dynamics and exotic shapes and fragmentation modes of hot nuclei are also addressed. In atomic physics, new measurements of x-ray emission from highly ionized ions, of molecular dissociation and of surface interactions are reported
Conserving RPA and the response of 48Ca
International Nuclear Information System (INIS)
Brand, M.G.E.; Allaart, K.; Dickhoff, W.H.
1988-01-01
The connection between the single-particle self-energy and the corresponding conserving particle-hole (ph) interaction, discussed long ago by Kadanoff and Baym, is employed to study the response of 48 Ca. Second order self-energy contributions are taken into account in the construction of the energy dependent ph interaction. From this perspective it is possible to make contact with other approaches which also aim to incorporate the coupling to 2p2h excitations within the RPA framework. The method is used to study both the discrete low-energy states as well as the giant resonances in both 48 Ca and 48 Sc using a realistic G matrix interaction based on meson exchange. The calculated strength distribution compares favorably with experimental but the strength below 15 MeV is still somewhat too large as compared to experiment for all types of excitations. The quenching of magnetic and Gamow-Teller strength due to 2p2h admixture amounts to about 30%. (orig.)
Shell structure from N=Z (100Sn) to N>>Z (78Ni)
International Nuclear Information System (INIS)
Grawe, H.
2003-01-01
The shell structure of 100 Sn shows striking resemblance to 56 Ni one major shell below. Large-scale shell model calculations employing realistic interactions derived from effective NN potentials and allowing for up to 4p4h excitations of the 100 Sn core account very well for the spectroscopy of key neighbours 102,103 Sn, 98 Cd and 94 Ag, as inferred from level energies, isomerism, E2 strengths and Gamow-Teller (GT) decay of high-spin states. Recent β- decay studies of 101-104 Sn using the sulphurisation ISOL technique open the perspective to study the 100 Sn GT resonance. At N>>Z the persistence of the N=50 and the weakness of the N=40 shells are traced back to the monopole interaction in S=0 proton-neutron (πν) pairs of nucleons, a scenario which can be generalised to account for the new N=6,16(14),34(32) magicity in light neutron-rich nuclei. (orig.)
Superconductivity, Mott-Hubbard states, and molecular orbital order in intercalated fullerides
Iwasa, Y
2003-01-01
This article reviews the current status of chemically doped fullerene superconductors and related compounds, with particular focus on Mott-Hubbard states and the role of molecular orbital degeneracy. Alkaline-earth metal fullerides produce superconductors of several kinds, all of which have states with higher valence than (C sub 6 sub 0) sup 6 sup - , where the second lowest unoccupied molecular orbital (the LUMO + 1 state) is filled. Alkali-metal-doped fullerides, on the other hand, afford superconductors only at the stoichiometry A sub 3 C sub 6 sub 0 (A denotes alkali metal) and in basically fcc structures. The metallicity and superconductivity of A sub 3 C sub 6 sub 0 compounds are destroyed either by reduction of the crystal symmetry or by change in the valence of C sub 6 sub 0. This difference is attributed to the narrower bandwidth in the A sub 3 C sub 6 sub 0 system, causing electronic instability in Jahn-Teller insulators and Mott-Hubbard insulators. The latter metal-insulator transition is driven by...
Indian Academy of Sciences (India)
Metropolis N, Rosenblueth A, Rosenblueth M, Teller A and Teller E 1953 Equation of state calculations by fast computing machines; J. Chem. Phys, 21 1087-1092 ... its properties and use for automated interpretation; Geophysics 37 507-517 y.
Spin-state responses to light impurity substitution in low-spin perovskite LaCoO3
Tomiyasu, Keisuke; Kubota, Yuuki; Shimomura, Saya; Onodera, Mitsugi; Koyama, Syun-Ichi; Nojima, Tsutomu; Ishihara, Sumio; Nakao, Hironori; Murakami, Youichi
2013-06-01
We studied the spin-state responses to light impurity substitution in low-spin perovskite LaCoO3 (Co3+: d6) through magnetization, x-ray fluorescence, and electrical resistivity measurements of single-crystal LaCo0.99M0.01O3 (M = Cr, Mn, Fe, Ni). In the magnetization curves measured at 1.8 K, a change in the spin-state was not observed for Cr, Mn, or Fe substitution but was observed for Ni substitution. Strong magnetic anisotropy was also found in the Ni-substituted sample. The fluorescence measurements revealed that the valences were roughly estimated to be Cr3+, Mn(4-δ)+, Fe(3+δ')+, and Ni3+. From the observed chemical trends, we propose that the chemical potential is a key factor in inducing the change of the low-spin state. By expanding a model of the ferromagnetic spin-state heptamer generated by hole doping [Podlesnyak , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.101.247603 101, 247603 (2008)], the emergence of highly anisotropic spin-state molecular ferromagnets induced by low-spin Ni3+ with Jahn-Teller activity is suggested. We also discuss applicability of the present results to other materials with Fe (d6).
Surface-hopping trajectories for OH(A{sup 2}Σ{sup +}) + Kr: Extension to the 1A″ state
Energy Technology Data Exchange (ETDEWEB)
Perkins, T.; McCrudden, G.; Brouard, M., E-mail: mark.brouard@chem.ox.ac.uk [The Department of Chemistry, The Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom); Herráez-Aguilar, D.; Aoiz, F.J., E-mail: aoiz@quim.ucm.es [Departamento de Química Física, Facultad de Química, Universidad Complutense, 28040 Madrid (Spain); Kłos, J., E-mail: jklos@umd.edu [Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742 (United States)
2015-04-14
We present a new trajectory surface hopping study of the rotational energy transfer and collisional quenching of electronically excited OH(A) radicals by Kr. The trajectory surface hopping calculations include both electronic coupling between the excited 2{sup 2}A′ and ground 1{sup 2}A′ electronic states, as well as Renner-Teller and Coriolis roto-electronic couplings between the 1{sup 2}A′ and 1{sup 2}A″, and the 2{sup 2}A′ and 1{sup 2}A″ electronic states, respectively. The new calculations are shown to lead to a noticeable improvement in the agreement between theory and experiment in this system, particularly with respect to the OH(X) rotational and Λ-doublet quantum state populations, compared with a simpler two-state treatment, which only included the electronic coupling between the 2{sup 2}A′ and 1{sup 2}A′ states. Discrepancies between the predictions of theory and experiment do however remain, and could arise either due to errors in the potential energy surfaces and couplings employed, or due to the limitations in the classical treatment of non-adiabatic effects.
International Nuclear Information System (INIS)
Wang, F.; Ping, J.L.; Quing, D.; Goldman, T.
2005-01-01
The pentaquark state recently discovered has been discussed based on various quark model calculations. Odd parity for the state cannot be ruled out theoretically because the contributions related to nontrivial color structures have not been studied completely. Other multiquark states, especially dibaryons, have been discussed also. A strangeness -3 NΩ dibaryons, have been shown to have a width as small as 12-22 keV and should be detectable in Ω-high-productivity reactions such as at RHIC, COMPAS, and the planned JHF and FAIR projects [ru
Histories and Horoscopes: The Ethnographer as Fortune-Teller.
Hamilton, Mary
1998-01-01
Focuses on different ways participants in a research project may understand the research and use it themselves by describing how 20 adult students and 14 community members, participants in a recent ethnographic study of adult literacy in England, responded to the invitation to collaborate with researchers in interpreting interview data. (SLD)
North Carolina Tales Fly with Fourth Grade Tellers
Westman, Gretchen Daub
2008-01-01
In fourth grade, North Carolina students are required to write their own personal narratives. The teachers felt that telling a story would be a great stepping stone toward writing one. Rather than focusing on grammar and the mechanics of writing, students could focus on story development and creativity. In this article, the author describes how…
Patients as story-tellers of healthcare journeys.
Lamprell, Klay; Braithwaite, Jeffrey
2016-09-01
There are gaps in our comprehension of patients' subjective experiences as they engage with and transit through the healthcare environments implicated in their treatment trajectories. Patients' stories, unlike patient experience data gathered in questionnaires and surveys, express the deeply personal, narrative nature of the journeys that patients take, creating opportunities for qualitative healthcare research. Yet narrative capabilities and propensities vary with individuals, and are affected by the stresses of illness and treatment. This article extends the growing interest in narrative competence training for both practitioners and patients with the investigation of a story-telling model that could facilitate patients to narrate their experiences of healthcare systems. This model is derived from the literary arts. In fiction and autobiography, the journey arc of the central character is often one in which he or she is compelled to leave the comfort of everyday life and face a series of extraordinary events involving challenge and change which forces the character towards practical, intellectual, psychological and philosophical adjustments that define, by the end of the story, the character's 'new normal'. This pattern is known as the 'hero journey'. Its parallels with patients' experiences of healthcare and the way people narrate their stories of illness have long been recognised. We present here a new idea for applying this model as a narrative structure by which patients may construct their stories about being in and moving through the healthcare system. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
On the path to fusion energy. Teller lecture 2005
International Nuclear Information System (INIS)
Tabak, M.
2007-01-01
There is a need to develop alternate energy sources in the coming century because fossil fuels will become depleted and their use may lead to global climate change. Inertial fusion can become such an energy source, but significant progress must be made before its promise is realized. The high-density approach to inertial fusion suggested by Nuckolls et al. leads reaction chambers compatible with civilian power production. Methods to achieve the good control of hydrodynamic stability and implosion symmetry required to achieve these high fuel densities will be discussed. Fast Ignition, a technique that achieves fusion ignition by igniting fusion fuel after it is assembled, will be described along with its gain curves. Fusion costs of energy for conventional hotspot ignition will be compared with those of Fast Ignition and their capital costs compared with advanced fission plants. Finally, techniques that may improve possible Fast Ignition gains by an order of magnitude and reduce driver scales by an order of magnitude below conventional ignition requirements are described. (author)
Norris Bradbury and Edward Teller: A Fission-Fusion Reaction
Energy Technology Data Exchange (ETDEWEB)
Meade, Roger Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2018-02-12
On a bright, sunny day in October 1945, a boisterous and jubilant crowd assembled in front of Fuller Lodge to watch as the Army-Navy “E” Award, a prestigious national honor given for “Excellence in Production” during World War II, was presented to the Los Alamos Laboratory. Major General Leslie Groves, the commanding officer of the Manhattan Project; Navy Commodore William S. (Deak) Parsons, the wartime leader of the Laboratory’s Ordnance Division; Robert Sproul, the President of the University of California; and J. Robert Oppenheimer accepted the award on behalf of the Laboratory.
International Development Research Centre (IDRC) Digital Library (Canada)
But as members of the international community, we can take advantage of .... The connections and their effects, between people and states, are not just more ...... children's IQs and are linked to attention disorders, aggression, and delinquency.
National Oceanic and Atmospheric Administration, Department of Commerce — Quarterly newsletter published by the American Association of State Climatologists. Library includes volumes 1 through 21, for the years 1977-1997.
U.S. Department of Health & Human Services — A list of a variety of averages for each state or territory as well as the national average, including each quality measure, staffing, fine amount and number of...
U.S. Department of Health & Human Services — A list of the state averages for the HCAHPS survey responses. HCAHPS is a national, standardized survey of hospital patients about their experiences during a recent...
International Nuclear Information System (INIS)
Morini, Filippo; Deleuze, Michael Simon; Watanabe, Noboru; Kojima, Masataka; Takahashi, Masahiko
2015-01-01
The influence of nuclear dynamics in the electronic ground state on the (e,2e) momentum profiles of dimethyl ether has been analyzed using the harmonic analytical quantum mechanical and Born-Oppenheimer molecular dynamics approaches. In spite of fundamental methodological differences, results obtained with both approaches consistently demonstrate that molecular vibrations in the electronic ground state have a most appreciable influence on the momentum profiles associated to the 2b 1 , 6a 1 , 4b 2 , and 1a 2 orbitals. Taking this influence into account considerably improves the agreement between theoretical and newly obtained experimental momentum profiles, with improved statistical accuracy. Both approaches point out in particular the most appreciable role which is played by a few specific molecular vibrations of A 1 , B 1 , and B 2 symmetries, which correspond to C–H stretching and H–C–H bending modes. In line with the Herzberg-Teller principle, the influence of these molecular vibrations on the computed momentum profiles can be unraveled from considerations on the symmetry characteristics of orbitals and their energy spacing
International Nuclear Information System (INIS)
Brouillard, F.
1983-01-01
This chapter considers the formation of Rydberg atoms; their radiative decay; their behavior in electric and electromagnetic fields; and their collisions with atoms and ions. Discusses electron capture into high excited states; laser excitation of Rydberg states; Stark shift and Stark mixing; field ionization; ionization in oscillating fields; thermal collisions of Rydberg atoms; fast collisions of Rydberg atoms; n-changing collisions; and charge exchange. Points out that a large amount of experimental work has been done on collisions of Rydberg atoms with neutral perturbers at thermal energies, and most of it concerns the destruction of Rydberg alkali atoms in collisions with rare gases
Multi-State Vibronic Interactions in Fluorinated Benzene Radical Cations.
Faraji, S.; Köppel, H.
2009-06-01
Conical intersections of potential energy surfaces have emerged as paradigms for signalling strong nonadiabatic coupling effects. An important class of systems where some of these effects have been analyzed in the literature, are the benzene and benzenoid cations, where the electronic structure, spectroscopy, and dynamics have received great attention in the literature. In the present work a brief overview is given over our theoretical treatments of multi-mode and multi-state vibronic interactions in the benzene radical cation and some of its fluorinated derivatives. The fluorobenzene derivatives are of systematic interest for at least two different reasons. (1) The reduction of symmetry by incomplete fluorination leads to a disappearance of the Jahn-Teller effect present in the parent cation. (2) A specific, more chemical effect of fluorination consists in the energetic increase of the lowest σ-type electronic states of the radical cations. The multi-mode multi-state vibronic interactions between the five lowest electronic states of the fluorobenzene radical cations are investigated theoretically, based on ab initio electronic structure data, and employing the well-established linear vibronic coupling model, augmented by quadratic coupling terms for the totally symmetric vibrational modes. Low-energy conical intersections, and strong vibronic couplings are found to prevail within the set of tilde{X}-tilde{A} and tilde{B}-tilde{C}-tilde{D} cationic states, while the interactions between these two sets of states are found to be weaker and depend on the particular isomer. This is attributed to the different location of the minima of the various conical intersections occurring in these systems. Wave-packet dynamical simulations for these coupled potential energy surfaces, utilizing the powerful multi-configuration time-dependent Hartree method are performed. Ultrafast internal conversion processes and the analysis of the MATI and photo-electron spectra shed new light
Olson, Cathy Applefeld
2013-01-01
When a music teacher is named Teacher of the Year for an entire state, one just know a special story awaits. The narrative of Heidi Welch, director of music at Hillsboro-Deering High School in New Hampshire, does not disappoint. Welch, who grew up in abject poverty and was often homeless, developed her love of music through memorizing and singing…
African Journals Online (AJOL)
Dr. Miles R. Cone
colonial history is the 'artificial nature' of Africa's state borders and the notion that statehood ..... Source: Central Intelligence Agency, 2003b. Scientia .... As a virtue of the lack of faith in the country's banking system, this move had the opposite ...
African Journals Online (AJOL)
principals randomly selected from one hundred secondary schools in Cross River State. The data collected ... There was no siyriificant influerlce of gender on principals' leadership styles effectiveness. ... result of the cultural stereotyping of males and females by .... schools were single sex boys, another 10 were single sex ...
Nuclear spin and isospin excitations
International Nuclear Information System (INIS)
Osterfeld, F.
1992-01-01
A review is given of our present knowledge of collective spin-isospin excitations in nuclei. Most of this knowledge comes from intermediate-energy charge-exchange reactions and from inelastic electron- and proton-scattering experiments. The nuclear-spin dynamics is governed by the spin-isospin-dependent two-nucleon interaction in the medium. This interaction gives rise to collective spin modes such as the giant Gamow-Teller resonances. An interesting phenomenon is that the measured total Gamow-Teller transition strength in the resonance region is much less than a model-independent sum rule predicts. Two physically different mechanisms have been discussed to explain this so-called quenching of the total Gamow-Teller strength: coupling to subnuclear degrees of freedom in the form of Δ-isobar excitation and ordinary nuclear configuration mixing. Both detailed nuclear structure calculations and extensive analyses of the scattering data suggest that the nuclear configuration mixing effect is the more important quenching mechanism, although subnuclear degrees of freedom cannot be ruled out. The quenching phenomenon occurs for nuclear-spin excitations at low excitation energies (ω∼10--20 MeV) and small-momentum transfers (q≤0.5 fm -1 ). A completely opposite effect is anticipated in the high (ω,q)-transfer region (0≤ω≤500 MeV, 0.5≤q≤3 fm -1 ). The nuclear spin-isospin response might be enhanced due to the attractive pion field inside the nucleus. Charge-exchange reactions at GeV incident energies have been used to study the quasifree peak region and the Δ-resonance region. An interesting result of these experiments is that the Δ excitation in the nucleus is shifted downwards in energy relative to the Δ excitation of the free proton
State of the States 2016: Arts Education State Policy Summary
Aragon, Stephanie
2016-01-01
The "State of the States 2016" summarizes state policies for arts education identified in statute or administrative code for all 50 states and the District of Columbia. Information is based on a comprehensive search of state education statute and codes on each state's relevant websites. Complete results from this review are available in…
Energy Technology Data Exchange (ETDEWEB)
Nakata, Hidehiko [Waseda Univ., Tokyo (Japan). Dept. of Physics; Tachibana, Takahiro; Yamada, Masami
1997-03-01
Recently the gross theory of nuclear {beta}-decay was refined for odd-odd nuclei. In this refinement, the effect of the selection rule of {beta}-transitions from the ground states of odd-odd nuclei to those of even-even nuclei was taken into account based on a statistical consideration. The transitions to the first 2{sup +} excited states in even-even nuclei were also taken into account according to the selection rule approximately. In that study, it was found that the transitions between 1{sup -} ground states of the odd-odd nuclei and 0{sup +} ground states of even-even nuclei, belonging to the first-forbidden transitions of rank 1, are strongly hindered. A reduction factor was introduced for the transitions to the ground states of even-even nuclei to take into account this hindrance. It was also found that the strength functions of the Gamow-Teller transitions obtained from the conventional gross theory are underestimated by a factor of about 3. In order to improve this underestimation, the Lorentz-type function was adopted for the one-particle strength function in the model instead of the hyperbolic-secant-type function. In the present study we have newly analyzed the experimental ft-values of odd-A nuclei, and found that the first-forbidden transitions of rank 1 are also considerably hindered between the ground states. Following the above refinement we have calculated the {beta}-ray spectra of some odd-odd short-lived fission products with the use of the refined gross theory. These results are compared not only with the experiments by Rudstam et al. but also with the conventional gross theory. (author)
Toward a measurement of weak magnetism in {sup 6}He decay
Energy Technology Data Exchange (ETDEWEB)
Huyan, X.; Naviliat-Cuncic, O., E-mail: naviliat@nscl.msu.edu; Bazin, D.; Gade, A.; Hughes, M.; Liddick, S.; Minamisono, K.; Noji, S.; Paulauskas, S. V.; Simon, A. [Michigan State University, National Superconducting Cyclotron Laboratory (United States); Voytas, P. [Wittenberg University, Department of Physics (United States); Weisshaar, D. [Michigan State University, National Superconducting Cyclotron Laboratory (United States)
2016-12-15
Sensitive searches for exotic scalar and tensor couplings in nuclear and neutron decays involve precision measurements of the shape of the β-energy spectrum. We have performed a high statistics measurement of the β-energy spectrum in the allowed Gamow-Teller decay of {sup 6}He with the aim to first find evidence of the contribution due to the weak magnetism form factor. We review here the motivation, describe the principle of the measurement, summarize the theoretical corrections to the allowed phase space, and anticipate the expected statistical precision.
Charge exchange reactions and the efficiency of solar neutrino detectors
International Nuclear Information System (INIS)
Austin, S.M.; Anantaraman, N.; Love, W.G.
1994-01-01
The efficiencies of solar neutrino detectors are often based in part on weak interaction strengths determined by (p,n) and other charge exchange reactions. Although the (p,n) determinations are surprisingly good, it is shown that they may be inaccurate for important Gamow-Teller transitions whose strengths are a small fraction of the sum rule limit. This emphasizes the importance of direct calibration with ν sources for detectors such as 127 I and 115 In where direct β-decay information cannot be obtained. It may also bear on recent attempts to compare charge exchange and beta decay in the mass-37 system
Energy Technology Data Exchange (ETDEWEB)
Kucuk, L.; Oktem, Y.; Cakirli, R.B.; Ganioglu, E.; Susoy, G. [Istanbul University, Department of Physics, Istanbul (Turkey); Orrigo, S.E.A.; Montaner-Piza, A.; Rubio, B. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Fujita, Y. [Osaka University, Department of Physics, Toyonaka, Osaka (Japan); Osaka University, Research Center for Nuclear Physics, Ibaraki, Osaka (Japan); Gelletly, W. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); University of Surrey, Department of Physics, Guildford, Surrey (United Kingdom); Blank, B.; Ascher, P.; Giovinazzo, J.; Grevy, S. [Centre d' Etudes Nucleaires de Bordeaux Gradignan, CNRS/IN2P3 - Universite de Bordeaux, Gradignan (France); Adachi, T.; Fujita, H.; Tamii, A. [Osaka University, Research Center for Nuclear Physics, Ibaraki, Osaka (Japan); Algora, A. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Inst. of Nuclear Research of the Hung. Acad. of Sciences, Debrecen (Hungary); France, G. de; Oliveira Santos, F. de; Thomas, J.C. [Grand Accelerateur National d' Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Caen (France); Marques, F.M. [Laboratoire de Physique Corpusculaire de Caen, ENSICAEN, UNICAEN, IN2P3/CNRS, Caen (France); Molina, F. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Comision Chilena de Energia Nuclear, Casilla 188-D, Santiago (Chile); Perrot, L. [IPN Orsay, Orsay (France); Raabe, R. [Grand Accelerateur National d' Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Caen (France); KU Leuven, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); Srivastava, P.C. [Grand Accelerateur National d' Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Caen (France); Indian Institute of Technology, Department of Physics, Roorkee (India)
2017-06-15
We have measured the β-decay half-lives of 16 neutron-deficient nuclei with T{sub z} = -1/2 and -1, ranging from chromium to germanium. They were produced in an experiment carried out at GANIL and optimized for the production of {sup 58}Zn, for which in addition we present the decay scheme and absolute Fermi and Gamow-Teller transition strengths. Since all of these nuclei lie on the rp-process pathway, the T{sub 1/2} values are important ingredients for the rp-process reaction flow calculations and for models of X-ray bursters. (orig.)
International Nuclear Information System (INIS)
Lienard, E.; Ban, G.; Blieck, J.; Durand, D.; Duval, F.; Flechard, X.; Herbane, M.; Labalme, M.; Lemiere, Y.; Mauger, F.; Mery, A.; Naviliat-Cuncic, O.; Rodriguez, D.; Thomas, J. C.
2006-01-01
We report on the status of the LPCTrap experiment, devoted to measure the β-ν angular correlation in the pure Gamow-Teller decay of 6 He. This measurement is motivated by the search for the presence of tensor type contributions to the weak interaction. The 6 He ions are confined in a novel transparent Paul trap. The β particles and the recoil ions are detected in coincidence to deduce the angular correlation parameter. The commissioning run performed in 2005 has given the proof of principle of this experiment. Up to 10 5 coincidences were recorded during a second run in 2006.
Measurement of the electron-neutrino angular correlation in 6He decay
International Nuclear Information System (INIS)
Naviliat-Cuncic, O.; Ban, G.; Durand, D.; Duval, F.; Flechard, X.; Herbane, M.; Labalme, M.; Lienard, E.; Mauger, F.; Mery, A.; Rodriguez-Rubiales, D.
2006-01-01
We report on the status of an experiment aiming to determine the angular correlation coefficient between the electron and the anti-neutrino in the pure Gamow-Teller decay of 6He. Such measurement is motivated by the search for the presence of tensor type contributions to the weak interaction. The experiment uses a setup where 6He ions are confined in a novel transparent Paul trap. Electrons and recoiling ions are detected in coincidence to deduce the angular correlation coefficient. First direct in trap decays have been recorded
Measurement Of The β-ν Correlation In 6He Using A Transparent Paul Trap
International Nuclear Information System (INIS)
Lienard, E.; Ban, G.; Darius, G.; Durand, D.; Flechard, X.; Herbane, M.; Labalme, M.; Mauger, F.; Mery, A.; Naviliat-Cuncic, O.; Rodriguez, D.
2006-01-01
The angular correlation between the electron and the neutrino in nuclear β-decay constitutes a sensitive observable to search for the existence of exotic couplings in the weak interaction. In this contribution, we describe the progress of the LPCTrap experiment, devoted to measure the β-ν angular correlation in the pure Gamow-Teller (GT) decay of 6He using a transparent Paul trap. We present a first coincidence spectrum, obtained during the commissioning run, which is the first β-recoil coincidence measurement obtained from any ion trap
Testing Lorentz invariance in β decay
Directory of Open Access Journals (Sweden)
Sytema A.
2014-03-01
Experimentally we exploit the Gamow-Teller transition of polarized 20Na, where we can test the dependence of the β-decay rate on the spin orientation of 20Na. The polarization degree is measured using the β asymmetry, while the decay rate is measured by the γ yield. A change in the γ rate, when reversing the spin, implies Lorentz invariance violation. The decay rate should depend on sidereal time and the polarization direction relative to the rotation axis of the earth. The method of the measurement will be presented, together with the first results.
Sizeable beta-strength in ^{31}Ar^{ (beta 3p) decay}
DEFF Research Database (Denmark)
T. Koldste, G.; Blank, B.; J. G. Borge, M.
2014-01-01
We present for the first time precise spectroscopic information on the recently discovered decay mode beta-delayed 3p-emission. The detection of the 3p events gives an increased sensitivity to the high energy part of the Gamow-Teller strength distribution from the decay of 31Ar revealing that as ...... that as much as 30% of the strength resides in the beta-3p decay mode. A simplified description of how the main decay modes evolve as the excitation energy increases in 31Cl is provided....
Limits on Tensor Coupling from Neutron $\\beta$-Decay
Pattie Jr, Robert W.; Hickerson, Kevin P.; Young, Albert R.
2013-01-01
Limits on the tensor couplings generating a Fierz interference term, b, in mixed Gamow-Teller Fermi decays can be derived by combining data from measurements of angular correlation parameters in neutron decay, the neutron lifetime, and $G_{\\text{V}}=G_{\\text{F}} V_{ud}$ as extracted from measurements of the $\\mathcal{F}t$ values from the $0^{+} \\to 0^{+}$ superallowed decays dataset. These limits are derived by comparing the neutron $\\beta$-decay rate as predicted in the standard model with t...
Beta Neutrino Correlation Measurement with Trapped Radioactive Ions
International Nuclear Information System (INIS)
Velten, Ph.; Ban, G.; Durand, D.; Flechard, X.; Lienard, E.; Mauger, F.; Naviliat-Cuncic, O.; Mery, A.; Rodriguez, D.; Thomas, J.-C.
2010-01-01
The beta-neutrino angular correlation coefficient provides a sensitive observable to search for physics beyond the standard electroweak model in nuclear beta decay. We address here the measurement of this parameter in the pure Gamow-Teller transition of 6 He. A deviation from the standard model prediction would indicate the existence of tensor like couplings, possibly mediated by new bosons like leptoquarks. The aim of the LPCTrap experiment is to measure this coefficient with a statistical uncertainty of 0.5% using a novel transparent Paul trap. The status of the experiment is briefly presented along with the work in progress.
Multipole decomposition analysis of the 27Al, 90Zr, 208Pb(p, n) reactions at 295 MeV
International Nuclear Information System (INIS)
Wakasa, T.; Greenfield, M.B.; Koori, N.; Okihana, A.; Hatanaka, K.
1996-01-01
Differential cross sections at θ lab between 0 and 15 and the polarization transfer D NN at zero degrees for the 27 Al, 90 Zr, 208 Pb(p,n) reactions are measured at a bombarding energy of 295 MeV. A multipole decomposition (MD) technique is applied to extract L=0, L=1, and L≥2 contributions to the cross sections. The summed Gamow-Teller strength B(GT) is compared with shell-model calculations for the 27 Al(p,n) and 90 Zr(p,n) reactions. The usefulness of the polarization transfer observable in the MD analysis is discussed. (orig.)
International Nuclear Information System (INIS)
Grotz, K.; Klapdor, H.V.; Metzinger, J.
1986-01-01
Calculations of the neutrino capture cross sections for /sup 69,71/Ga based on a microscopic treatment of the Gamow-Teller matrix elements are presented. A strong enhancement of the cross section for highly energetic neutrinos is found compared to previous phenomenological estimates. As a consequence, the present assumptions on the signal from 8 B neutrinos in 71 Ga have to be revised. A non-negligible solar model dependent background of 8 B neutrinos has to be expected in a gallium solar neutrino experiment together with the pp signal. The calculations yield a larger sensitivity of the gallium detector than assumed previously for galactic neutrinos
Role of chiral symmetry in nuclear physics
International Nuclear Information System (INIS)
Rho, M.
1985-01-01
Spurred by some recent experiments in electron scattering, the author reassesses the role that chiral symmetry plays in nuclear structure. Though difficult to formulate precisely, some of the ideas put forward many years ago, combined with the recent revival of the Skyrmion picture of the nucleon, are seen to be more relevant now than ever. Three relevant experiments and theoretical interpretations are discussed: M1 transitions in p(n,γ)d and d(e,e')np; axial charge transition in 16 N → 16 O + e + neutrino; and Gamow-Teller transitions and isobar currents. (Auth.)
Computational nuclear structure: Challenges, rewards, and prospects
International Nuclear Information System (INIS)
Dean, D.J.
1997-12-01
The shell model Monte Carlo technique (SMMC) transforms the traditional nuclear shell model problem into a path-integral over auxiliary fields. Applications of the method to studies of various properties of fp-shell nuclei, including Gamow-Teller strengths and distributions, are reviewed. Part of the future of nuclear structure physics lies in the study of nuclei far from beta-stability. The author discusses preliminary work on proton deficient Xe isotopes, and on neutron rich nuclei in the sd-Jp shells
Very proton-rich nuclei with N asymptotically equals 82
International Nuclear Information System (INIS)
Nolte, E.
1984-01-01
The proton-rich nuclei with N asymptotically equals 82 show beautifully properties, which are perfectly described by the nuclear shell model. Some of these properties are the occurrence of seniority isomerism in the proton-rich N=82 isotones and the perfect description of the corresponding life times by the seniority scheme as well as the observation of favoured Gamow-Teller β transitions in this nuclear region and the dependence of the corresponding ft values on the number of the envolved nucleons. (author)
Probing the N = Z Line via β Decay
International Nuclear Information System (INIS)
Markku Oinonen
1999-01-01
This contribution reports several beta-decay studies performed at ISOLDE On-Line Mass Separator at CERN recently for nuclei close to N = Z line. Beta decay of 58 Zn provides a possibility to compare Gamow-Teller strength extracted from complementary beta-decay studies and charge-exchange reactions. Measurement on beta-decay half-life of 70 Kr shows importance of experimental information in modeling the path of the astrophysical rp process. Decay of 71 Kr is an example of a mirror beta decay and extends the systematics of these particular decays towards highly deformed region close to A = 80
Electron-capture Rates for pf-shell Nuclei in Stellar Environments and Nucleosynthesis
Suzuki, Toshio; Honma, Michio; Mori, Kanji; Famiano, Michael A.; Kajino, Toshitaka; Hidakai, Jun; Otsuka, Takaharu
Gamow-Teller strengths in pf-shell nuclei obtained by a new shell-model Hamltonian, GXPF1J, are used to evaluate electron-capture rates in pf-shell nuclei at stellar environments. The nuclear weak rates with GXPF1J, which are generally smaller than previous evaluations for proton-rich nuclei, are applied to nucleosynthesis in type Ia supernova explosions. The updated rates are found to lead to less production of neutron-rich nuclei such as 58Ni and 54Cr, thus toward a solution of the problem of over-production of neutron-rich isotopes of iron-group nuclei compared to the solar abundance.
International Nuclear Information System (INIS)
Sugarbaker, E.
1995-01-01
I review available techniques for extraction of weak interaction rates in nuclei. The case for using hadron charge exchange reactions to estimate such rates is presented and contrasted with alternate methods. Limitations of the (p,n) reaction as a probe of Gamow-Teller strength are considered. Review of recent comparisons between beta-decay studies and (p,n) is made, leading to cautious optimism regarding the final usefulness of (p,n)- derived GT strengths to the field of astrophysics. copyright 1995 American Institute of Physics
Weak interaction rates for Kr and Sr waiting-point nuclei under rp-process conditions
International Nuclear Information System (INIS)
Sarriguren, P.
2009-01-01
Weak interaction rates are studied in neutron deficient Kr and Sr waiting-point isotopes in ranges of densities and temperatures relevant for the rp process. The nuclear structure is described within a microscopic model (deformed QRPA) that reproduces not only the half-lives but also the Gamow-Teller strength distributions recently measured. The various sensitivities of the decay rates to both density and temperature are discussed. Continuum electron capture is shown to contribute significantly to the weak rates at rp-process conditions.
Deformation of the N=Z nucleus $^{76}$Sr using $\\beta$-decay studies
Nacher, E; Rubio, B; Taín, J L; Cano-Ott, D; Courtin, S; Dessagne, P; Maréchal, F; Miehé, C; Poirier, E; García-Borge, M J; Escrig, D; Jungclaus, A; Sarriguren, P; Tengblad, O; Gelletly, W; Fraile-Prieto, L M; Le Scornet, G; Dessagne, Ph.; Miehe, Ch.
2004-01-01
A novel method of deducing the deformation of the N=Z nucleus $^{76}$Sr is presented. It is based on the comparison of the experimental Gamow-Teller strength distribution B(GT) from its $\\beta$-decay with the results of QRPA calculations. This method confirms previous indications of the strong prolate deformation of this nucleus in a totally independent and novel way. The measurement has been carried out with a large Total Absorption Gamma Spectrometer, "Lucrecia", newly installed at CERN-ISOLDE.
International Nuclear Information System (INIS)
Neill, R.H.
1985-01-01
Expectations by States in fulfilling their responsibilities in the disposal of radioactive wastes as defined in the Nuclear Waste Policy Act are discussed. Specific areas include informational needs, participation in the process of site selection and characterization, access to technical data in a timely manner, and development of consultation and cooperation agreements. Experiences in New Mexico over the past seven years in conducting an independent technical review of the WIPP Project are described. A discussion is included of avoidable factors that contribute to public concern of radioactive waste disposal on relative risk, voluntary versus involuntary risk, technological needs, changes in disposal practices, public health concerns and enforcement of regulations
Effect of Co substitution on magnetic ground state in Sm0.5Ca0.5MnO3
International Nuclear Information System (INIS)
Xu, Xiaolong; Li, Yu; Hou, Feifei; Cheng, Qian; Su, Runzhou
2015-01-01
Highlights: • Polycrystalline Sm 0.5 Ca 0.5 Mn 1−x Co x O 3 were prepared by standard solid-state reaction. • The orthorhombic deformation and normalized slope were calculated for each sample. • Critical slowing down model and dynamic scaling equation are applied in some samples. • Canted antiferromagnetic state via spin glass state, changes to ferrimagnetic state. - Abstract: The effect of cobalt doping on the structural and magnetic properties of polycrystalline Sm 0.5 Ca 0.5 Mn 1−x Co x O 3 (0 ⩽ x ⩽ 0.20) has been studied. Powder X-ray diffraction (XRD), dc magnetization and ac susceptibility measurements have been performed. The orthorhombic deformation caused by the Jahn–Teller (JT) effect can be counterbalanced by Co 3+ doping. Meanwhile, antiferromagnetic (AFM), spin glass (SG) and phase separation (PS) ferrimagnetic states appear, successively, with the increase of x. The critical slowing down model and the dynamic scaling equation were applied in some samples. The existence of two distinct length scales for SG and finite FM (ferromagnetic) order is the source of the progressive deviation which exists in the dynamic scaling fitting for x = 0.05. Moreover, the small peaks at ∼8 K in χ″(T) curves are believed to be induced by the canted moments of Mn ions as observed in Nd 2/3 Ca 1/3 MnO 3
Analytical equation of state with three-body forces: Application to noble gases
International Nuclear Information System (INIS)
Río, Fernando del; Díaz-Herrera, Enrique; Guzmán, Orlando; Moreno-Razo, José Antonio; Ramos, J. Eloy
2013-01-01
We developed an explicit equation of state (EOS) for small non polar molecules by means of an effective two-body potential. The average effect of three-body forces was incorporated as a perturbation, which results in rescaled values for the parameters of the two-body potential. These values replace the original ones in the EOS corresponding to the two-body interaction. We applied this procedure to the heavier noble gases and used a modified Kihara function with an effective Axilrod-Teller-Muto (ATM) term to represent the two- and three-body forces. We also performed molecular dynamics simulations with two- and three-body forces. There was good agreement between predicted, simulated, and experimental thermodynamic properties of neon, argon, krypton, and xenon, up to twice the critical density and up to five times the critical temperature. In order to achieve 1% accuracy of the pressure at liquid densities, the EOS must incorporate the effect of ATM forces. The ATM factor in the rescaled two-body energy is most important at temperatures around and lower than the critical one. Nonetheless, the rescaling of two-body diameter cannot be neglected at liquid-like densities even at high temperature. This methodology can be extended straightforwardly to deal with other two- and three-body potentials. It could also be used for other nonpolar substances where a spherical two-body potential is still a reasonable coarse-grain approximation
State of the States, 2012: Arts Education State Policy Summary
Arts Education Partnership (NJ1), 2012
2012-01-01
The "State of the States 2012" summarizes state policies for arts education identified in statute or code for all 50 states and the District of Columbia. Information is based primarily on results from the AEP Arts Education State Policy Survey conducted in 2010-11, and updated in April 2012.
Coherent states: a contemporary panorama Coherent states: a contemporary panorama
Twareque Ali, S.; Antoine, Jean-Pierre; Bagarello, Fabio; Gazeau, Jean-Pierre
2012-06-01
magnetic field (Hall-Mitchell) a paper on CS for a quantum particle on a Möbius strip (Cirilo-Lombardo) a discussion of quantization on the circle (Chadzitaskos et al); SUSY CS for Pöschl-Teller potentials (Bergeron et al); generalized Bargmann functions and von Neumann lattices (Vourdas et al); partial reconstruction for a finite CS system, using the Fock-Bargmann representation (Calixto et al); phase operators for SU(3) irreps, thus for finite quantum systems (de Guise); semiclassical CS in periodic potentials (Carles-Sparber) complexified CS with non-Hermitian Hamiltonians (Graefe-Schubert) minimal uncertainty states in the context of (semisimple) group representation theory (Oszmaniec); localization operators in the time-frequency domain, i.e., in Gabor analysis (Muzhikyan-Avanesyan) and, finally, two papers about fermionic CS (Daoud-Kibler and Trifonov). This brief description illustrates perfectly the extreme versatility of the CS concept. As already stressed, coherent states constitute nowadays a flourishing research topic, with applications to a wide spectrum of domains. Indeed, CS are everywhere in physics: condensed matter physics, atomic physics, nuclear and particle physics, quantum optics, dynamics—both quantum and classical potentials—quantum gravity, quantization and quantum information theory. On the other hand, CS have grown into a fully-fledged domain in mathematics, incorporating many tools such as group representations, POV measures, frames, holomorphic functions, orthogonal polynomials and so on. Interestingly enough, the majority of contributions to this special issue (22 out of 37) are mathematically minded, demonstrating the widespread interest CS have generated in various areas of mathematics. A third field related to CS (but almost not represented in the present collection) is signal processing. Indeed both Gabor analysis and wavelet analysis derive in the first place from CS theory, namely, CS associated to the Weyl-Heisenberg and the ax
Energy Technology Data Exchange (ETDEWEB)
Zhou, Linsen [Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Institute of Theoretical and Computational Chemistry, Nanjing University, Nanjing 210093 (China); Xie, Daiqian, E-mail: dqxie@nju.edu.cn, E-mail: hguo@unm.edu [Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Institute of Theoretical and Computational Chemistry, Nanjing University, Nanjing 210093 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Guo, Hua, E-mail: dqxie@nju.edu.cn, E-mail: hguo@unm.edu [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States)
2015-03-28
A detailed quantum mechanical characterization of the photodissociation dynamics of H{sub 2}O at 121.6 nm is presented. The calculations were performed using a full-dimensional wave packet method on coupled potential energy surfaces of all relevant electronic states. Our state-to-state model permits a detailed analysis of the OH(X{sup ~}/A{sup ~}) product fine-structure populations as a probe of the non-adiabatic dissociation dynamics. The calculated rotational state distributions of the two Λ-doublet levels of OH(X{sup ~}, v = 0) exhibit very different characteristics. The A′ states, produced mostly via the B{sup ~}→X{sup ~} conical intersection pathway, have significantly higher populations than the A″ counterparts, which are primarily from the B{sup ~}→A{sup ~} Renner-Teller pathway. The former features a highly inverted and oscillatory rotational state distribution, while the latter has a smooth distribution with much less rotational excitation. In good agreement with experiment, the calculated total OH(X{sup ~}) rotational state distribution and anisotropy parameters show clear even-odd oscillations, which can be attributed to a quantum mechanical interference between waves emanating from the HOH and HHO conical intersections in the B{sup ~}→X{sup ~} non-adiabatic pathway. On the other hand, the experiment-theory agreement for the OH(A{sup ~}) fragment is also satisfactory, although some small quantitative differences suggest remaining imperfections of the ab initio based potential energy surfaces.
International Nuclear Information System (INIS)
Zhou, Linsen; Xie, Daiqian; Guo, Hua
2015-01-01
A detailed quantum mechanical characterization of the photodissociation dynamics of H 2 O at 121.6 nm is presented. The calculations were performed using a full-dimensional wave packet method on coupled potential energy surfaces of all relevant electronic states. Our state-to-state model permits a detailed analysis of the OH(X ~ /A ~ ) product fine-structure populations as a probe of the non-adiabatic dissociation dynamics. The calculated rotational state distributions of the two Λ-doublet levels of OH(X ~ , v = 0) exhibit very different characteristics. The A′ states, produced mostly via the B ~ →X ~ conical intersection pathway, have significantly higher populations than the A″ counterparts, which are primarily from the B ~ →A ~ Renner-Teller pathway. The former features a highly inverted and oscillatory rotational state distribution, while the latter has a smooth distribution with much less rotational excitation. In good agreement with experiment, the calculated total OH(X ~ ) rotational state distribution and anisotropy parameters show clear even-odd oscillations, which can be attributed to a quantum mechanical interference between waves emanating from the HOH and HHO conical intersections in the B ~ →X ~ non-adiabatic pathway. On the other hand, the experiment-theory agreement for the OH(A ~ ) fragment is also satisfactory, although some small quantitative differences suggest remaining imperfections of the ab initio based potential energy surfaces
Zhou, Linsen; Xie, Daiqian; Guo, Hua
2015-03-01
A detailed quantum mechanical characterization of the photodissociation dynamics of H2O at 121.6 nm is presented. The calculations were performed using a full-dimensional wave packet method on coupled potential energy surfaces of all relevant electronic states. Our state-to-state model permits a detailed analysis of the OH( X ˜ / A ˜ ) product fine-structure populations as a probe of the non-adiabatic dissociation dynamics. The calculated rotational state distributions of the two Λ-doublet levels of OH( X ˜ , v = 0) exhibit very different characteristics. The A' states, produced mostly via the B ˜ → X ˜ conical intersection pathway, have significantly higher populations than the A″ counterparts, which are primarily from the B ˜ → A ˜ Renner-Teller pathway. The former features a highly inverted and oscillatory rotational state distribution, while the latter has a smooth distribution with much less rotational excitation. In good agreement with experiment, the calculated total OH( X ˜ ) rotational state distribution and anisotropy parameters show clear even-odd oscillations, which can be attributed to a quantum mechanical interference between waves emanating from the HOH and HHO conical intersections in the B ˜ → X ˜ non-adiabatic pathway. On the other hand, the experiment-theory agreement for the OH( A ˜ ) fragment is also satisfactory, although some small quantitative differences suggest remaining imperfections of the ab initio based potential energy surfaces.
Zhou, Linsen; Xie, Daiqian; Guo, Hua
2015-03-28
A detailed quantum mechanical characterization of the photodissociation dynamics of H2O at 121.6 nm is presented. The calculations were performed using a full-dimensional wave packet method on coupled potential energy surfaces of all relevant electronic states. Our state-to-state model permits a detailed analysis of the OH(X̃/Ã) product fine-structure populations as a probe of the non-adiabatic dissociation dynamics. The calculated rotational state distributions of the two Λ-doublet levels of OH(X̃, v = 0) exhibit very different characteristics. The A' states, produced mostly via the B̃→X̃ conical intersection pathway, have significantly higher populations than the A″ counterparts, which are primarily from the B̃→Ã Renner-Teller pathway. The former features a highly inverted and oscillatory rotational state distribution, while the latter has a smooth distribution with much less rotational excitation. In good agreement with experiment, the calculated total OH(X̃) rotational state distribution and anisotropy parameters show clear even-odd oscillations, which can be attributed to a quantum mechanical interference between waves emanating from the HOH and HHO conical intersections in the B̃→X̃ non-adiabatic pathway. On the other hand, the experiment-theory agreement for the OH(Ã) fragment is also satisfactory, although some small quantitative differences suggest remaining imperfections of the ab initio based potential energy surfaces.
Quantum States Transfer by Analogous Bell States
International Nuclear Information System (INIS)
Mei Di; Li Chong; Yang Guohui; Song Heshan
2008-01-01
Transmitting quantum states by channels of analogous Bell states is studied in this paper. We analyze the transmitting process, constructed the probabilitic unitary operator, and gain the largest successful transfer quantum state probability.
International Nuclear Information System (INIS)
Raduta, A. A.; Delion, D. S.; Faessler, A.
1998-01-01
The suppression mechanism of the Gamow-Teller double beta decay amplitude M GT is studied using a many body Hamiltonian which describes a composite system of protons and neutrons moving in a projected spherical single particle basis. Alike nucleons interact through pairing, while protons and neutrons by a separable dipole-dipole force both in the particle-hole (ph) and particle-particle (pp) channels. The spin-flip and non-spin-flip components of the QRPA phonons have different contributions to the M GT value. The relative magnitudes and phases depend on both the strength of the particle-particle interaction (g pp ) and nuclear deformation. The deformation yields a fragmentation of the M GT value on one hand and washes out the separation of states of pure spin-flip and non spin-flip structures. Due to this effect, M GT has only one fragmented resonance structure in the low part of the spectrum. The mechanism of M GT suppression is different for spherical and deformed nuclei. While for spherical situation the resonances of pure spin-flip and non spin-flip character are separated in energy, for deformed case the two resonances coincide. In both cases, approaching the critical value of g pp , where the Random Phase Approximation (RPA) breaks down, a lot of strength is accumulated in the lowest RPA state. The difference is that, while in the spherical case this has a non spin-flip nature, in the deformed case the state is a mixture of both types of configurations. (authors)
Progress in research, April 1, 1981-March 31, 1982
International Nuclear Information System (INIS)
Youngblood, D.H.
1982-06-01
During the year April 1, 1981 to March 31, 1982 a wide variety of both experimental and theoretical programs were underway, and some examples of recent work in areas of current interest are described. The transition nucleus 148 Sm has been shown to have considerable mixing of the giant quadrupole and monopole resonances; no distinct separate monopole resonances; no distinct separate monopole is observed. Massive transfer reaction have been shown to be an excellent means of producing nuclei within a narrow range of angular momentum for gamma ray spectroscopic studies; in some cases, states in neutron-rich nuclei have been produced which cannot be populated with the usual compound nuclear reactions. Evidence has been obtained for a large spin enhancement in heavy-ion induced fission due to the excitation of collective modes. The analyzing powers A/sub y/ and A/sub yy/ for the 1 H(d,n)2p breakup reaction have been measured at 42.4 MeV at 0 0 and 18 0 . High resolution measurements of x-ray emission in heavy-ion collisions have provided new evidence for resonant electron transfer, and have led to the observation of aligned atomic states in helium-like heavy ions. In theoretical efforts a quantum mechanical theory of fission was shown to lead to the barrier-state formula for fission lifetimes of excited nuclei. The first continuum RPA computation of a Gamow-Teller resonance was completed and pions were shown to be responsible for the enhancement of subthreshold K - production in heavy-ion collision
Towards 100Sn: Studies on neutron-deficient even isotopes of tin
International Nuclear Information System (INIS)
Rathke, G.E.
1987-02-01
Neutron-deficient 108,106,104 Sn isotopes were produced by heavy ion induced fusion reactions using high-intensity 59 Ni beams from the UNILAC of the GSI. Their decay properties were studied by techniques of gamma and conversion electron spectroscopy employing the mass separator on-line to the UNILAC. Earlier information on the 108 Sn → 108 In and 106 Sn → 106 In decays was complemented and improved in the course of this work. The new nucleus 104 Sn and its decay to excited states in 104 In was identified and studied for the first time. These investigations yield the following results: the mass of 104 Sn and of nuclei linked to it by alpha decay or proton radioactivity, 108 Te, 112 Xe and 109 I, 113 Cs, respectively were determined from the measured Q EC value of 104 Sn and the known mass value of 104 In. These are nuclei very close or beyond the proton drip line. In addition, information on the quenching of the fast Gamow-Teller beta decay of the even neutron-deficient tin isotopes was obtained. This complements investigations on the N = 50 isotones 94 Ru and 96 Pd, and allows a systematic comparison of these transition strengths for nuclei near the doubly magic 100 Sn. The spreading of the vertical strokeπg 9/2 -1 vg 7/2 , 1 + > configuration over several states, due to residual interactions, and the centroid energies of these magnetic dipole states were determined for the corresponding odd-odd indium isotopes. (orig./HSI)
Beta-decay rate and beta-delayed neutron emission probability of improved gross theory
Koura, Hiroyuki
2014-09-01
A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for unmeasured nuclei are adopted from the KTUY nuclear mass formula, which is based on the spherical-basis method. Considering the properties of the integrated Fermi function, we can roughly categorized energy region of excited-state of a daughter nucleus into three regions: a highly-excited energy region, which fully affect a delayed neutron probability, a middle energy region, which is estimated to contribute the decay heat, and a region neighboring the ground-state, which determines the beta-decay rate. Some results will be given in the presentation. A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for
Palmer, Michael H.; Vrønning Hoffmann, Søren; Jones, Nykola C.; Coreno, Marcello; de Simone, Monica; Grazioli, Cesare
2018-06-01
The vacuum ultraviolet (VUV) spectrum for CH2F2 from a new synchrotron study has been combined with earlier data and subjected to detailed scrutiny. The onset of absorption, band I and also band IV, is resolved into broad vibrational peaks, which contrast with the continuous absorption previously claimed. A new theoretical analysis, using a combination of time dependent density functional theory (TDDFT) calculations and complete active space self-consistent field, leads to a major new interpretation. Adiabatic excitation energies (AEEs) and vertical excitation energies, evaluated by these methods, are used to interpret the spectra in unprecedented detail using theoretical vibronic analysis. This includes both Franck-Condon (FC) and Herzberg-Teller (HT) effects on cold and hot bands. These results lead to the re-assignment of several known excited states and the identification of new ones. The lowest calculated AEE sequence for singlet states is 11B1 ˜ 11A2 expected; the onset of the 15.5 eV band shows a set of vibrational peaks, but the vibration frequency does not correspond to any of the photoelectron spectral (PES) structure and is clearly valence in nature. The routine use of PES footprints to detect Rydberg states in VUV spectra is shown to be inadequate. The combined effects of FC and HT in the VUV spectral bands lead to additional vibrations when compared with the PES.
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The nuclear deformation versus spin-flip like excitations and the suppression of the 2νββ amplitude
International Nuclear Information System (INIS)
Raduta, A.A.; Delion, D.S.; Faessler, Amand
1997-01-01
We were the first who investigated the influence of spin-flip and non-spin-flip configuration on the separation of the transition amplitude of the Gamow-Teller double beta decay. A realistic Hamiltonian and a projected spherical single particle basis is considered, while the effects are generated by three antagonistic sources: spin-flip, non-spin-flip like excitation and nuclear deformation. Moreover, by a smooth variation of a deformation parameter one could bridge the spherical and deformed pictures. Although our application is not aimed at describing the experimental situation we chose as input data those corresponding to the transition 82 Se → 82 Kr. For near spherical case there are two resonances in M GT , one having a spin-flip structure and identified as GT resonance and one of non-spin-flip structure, placed at low energy. For large deformation and vanishing g pp coupling constant there are two resonances of spin-flip and non-spin-flip natures (ΔI = 1 and 0, respectively) and located at the same energy, what indicates that the deformation acts against the separation of this resonances. In conclusion, our calculation showed that the mechanism of M GT suppression is different for spherical and deformed nuclei. In both cases approaching the critical value of g pp where the RPA breaks down, a lot of strength is accumulated in lowest RPA state and, while in the spherical case this has a non spin-flip nature, in the deformed case the state is a mixture of both types of configurations
Minimal nuclear energy density functional
Bulgac, Aurel; Forbes, Michael McNeil; Jin, Shi; Perez, Rodrigo Navarro; Schunck, Nicolas
2018-04-01
We present a minimal nuclear energy density functional (NEDF) called "SeaLL1" that has the smallest number of possible phenomenological parameters to date. SeaLL1 is defined by seven significant phenomenological parameters, each related to a specific nuclear property. It describes the nuclear masses of even-even nuclei with a mean energy error of 0.97 MeV and a standard deviation of 1.46 MeV , two-neutron and two-proton separation energies with rms errors of 0.69 MeV and 0.59 MeV respectively, and the charge radii of 345 even-even nuclei with a mean error ɛr=0.022 fm and a standard deviation σr=0.025 fm . SeaLL1 incorporates constraints on the equation of state (EoS) of pure neutron matter from quantum Monte Carlo calculations with chiral effective field theory two-body (NN ) interactions at the next-to-next-to-next-to leading order (N3LO) level and three-body (NNN ) interactions at the next-to-next-to leading order (N2LO) level. Two of the seven parameters are related to the saturation density and the energy per particle of the homogeneous symmetric nuclear matter, one is related to the nuclear surface tension, two are related to the symmetry energy and its density dependence, one is related to the strength of the spin-orbit interaction, and one is the coupling constant of the pairing interaction. We identify additional phenomenological parameters that have little effect on ground-state properties but can be used to fine-tune features such as the Thomas-Reiche-Kuhn sum rule, the excitation energy of the giant dipole and Gamow-Teller resonances, the static dipole electric polarizability, and the neutron skin thickness.
Optimal resource states for local state discrimination
Bandyopadhyay, Somshubhro; Halder, Saronath; Nathanson, Michael
2018-02-01
We study the problem of locally distinguishing pure quantum states using shared entanglement as a resource. For a given set of locally indistinguishable states, we define a resource state to be useful if it can enhance local distinguishability and optimal if it can distinguish the states as well as global measurements and is also minimal with respect to a partial ordering defined by entanglement and dimension. We present examples of useful resources and show that an entangled state need not be useful for distinguishing a given set of states. We obtain optimal resources with explicit local protocols to distinguish multipartite Greenberger-Horne-Zeilinger and graph states and also show that a maximally entangled state is an optimal resource under one-way local operations and classical communication to distinguish any bipartite orthonormal basis which contains at least one entangled state of full Schmidt rank.
International Nuclear Information System (INIS)
Tokoro, Hiroko; Hashimoto, Kazuhito; Ohkoshi, Shin-ichi
2007-01-01
A charge transfer phase transition with thermal hysteresis loop is observed in a series of rubidium manganese hexacyanoferrates, RbMn[Fe(China) 6 ] (1), Rb 0.88 Mn[Fe(China) 6 ] 0.96 .0.6H 2 O (2), and Rb 0.97 Mn[Fe(China) 6 ] 0.99 .0.2H 2 O (3). This phase transition is accompanied by a structural change from cubic (F4-bar 3m) to tetragonal (I4-bar m2). Its high-temperature (HT) and low-temperature (LT) phases are composed of Mn II (S=2/5)NC-Fe III (S=1/2) and Mn III (S=2)-NC-Fe II (S=0), respectively. The phase transition is caused by a metal-to-metal charge transfer from Mn II to Fe III and a Jahn-Teller distortion of the produced Mn III ion. At the ferromagnetic state in LT phase of 2, the photo-induced phase transition is observed, i.e., magnetization is quenched by the irradiation with only one shot of laser pulse. This phenomenon is caused by a photo-induced phase transition from the LT phase to the HT phase. In 3, optical switching between LT and HT phases at room temperature in paramagnetic region is observed
Uncertainties in constraining low-energy constants from {sup 3}H β decay
Energy Technology Data Exchange (ETDEWEB)
Klos, P.; Carbone, A.; Hebeler, K. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, ExtreMe Matter Institute EMMI, Darmstadt (Germany); Menendez, J. [University of Tokyo, Department of Physics, Tokyo (Japan); Schwenk, A. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, ExtreMe Matter Institute EMMI, Darmstadt (Germany); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)
2017-08-15
We discuss the uncertainties in constraining low-energy constants of chiral effective field theory from {sup 3}H β decay. The half-life is very precisely known, so that the Gamow-Teller matrix element has been used to fit the coupling c{sub D} of the axial-vector current to a short-range two-nucleon pair. Because the same coupling also describes the leading one-pion-exchange three-nucleon force, this in principle provides a very constraining fit, uncorrelated with the {sup 3}H binding energy fit used to constrain another low-energy coupling in three-nucleon forces. However, so far such {sup 3}H half-life fits have only been performed at a fixed cutoff value. We show that the cutoff dependence due to the regulators in the axial-vector two-body current can significantly affect the Gamow-Teller matrix elements and consequently also the extracted values for the c{sub D} coupling constant. The degree of the cutoff dependence is correlated with the softness of the employed NN interaction. As a result, present three-nucleon forces based on a fit to {sup 3}H β decay underestimate the uncertainty in c{sub D}. We explore a range of c{sub D} values that is compatible within cutoff variation with the experimental {sup 3}H half-life and estimate the resulting uncertainties for many-body systems by performing calculations of symmetric nuclear matter. (orig.)
Tz=-1 →0 β decays of 54Ni,50Fe,46Cr, and 42Ti and comparison with mirror (3He,t ) measurements
Molina, F.; Rubio, B.; Fujita, Y.; Gelletly, W.; Agramunt, J.; Algora, A.; Benlliure, J.; Boutachkov, P.; Cáceres, L.; Cakirli, R. B.; Casarejos, E.; Domingo-Pardo, C.; Doornenbal, P.; Gadea, A.; Ganioǧlu, E.; Gascón, M.; Geissel, H.; Gerl, J.; Górska, M.; GrÈ©bosz, J.; Hoischen, R.; Kumar, R.; Kurz, N.; Kojouharov, I.; Susam, L. Amon; Matsubara, H.; Morales, A. I.; Oktem, Y.; Pauwels, D.; Pérez-Loureiro, D.; Pietri, S.; Podolyák, Zs.; Prokopowicz, W.; Rudolph, D.; Schaffner, H.; Steer, S. J.; Tain, J. L.; Tamii, A.; Tashenov, S.; Valiente-Dobón, J. J.; Verma, S.; Wollersheim, H.-J.
2015-01-01
We have studied the β decay of the Tz=-1 ,f7 /2 shell nuclei 54Ni,50Fe,46Cr, and 42Ti produced in fragmentation reactions. The proton separation energies in the daughter Tz=0 nuclei are relatively large (≈4 -5 MeV) so studies of the γ rays are essential. The experiments were performed at GSI as part of the Stopped-beam campaign with the RISING setup consisting of 15 Euroball Cluster Ge detectors. From the newly obtained high precision β -decay half-lives, excitation energies, and β branching ratios, we were able to extract Fermi and Gamow-Teller transition strengths in these β decays. With these improved results it was possible to compare in detail the Gamow-Teller (GT) transition strengths observed in beta decay including a sensitivity limit with the strengths of the Tz=+1 to Tz=0 transitions derived from high resolution (3He ,t ) reactions on the mirror target nuclei at RCNP, Osaka. The accumulated B (GT) strength obtained from both experiments looks very similar although the charge exchange reaction provides information on a broader energy range. Using the "merged analysis" one can obtain a full picture of the B (GT) over the full Qβ range. Looking at the individual transitions some differences are observed, especially for the weak transitions. Their possible origins are discussed.
Impact of electron-captures on nuclei near N = 50 on core-collapse supernovae
Titus, R.; Sullivan, C.; Zegers, R. G. T.; Brown, B. A.; Gao, B.
2018-01-01
The sensitivity of the late stages of stellar core collapse to electron-capture rates on nuclei is investigated, with a focus on electron-capture rates on 74 nuclei with neutron number close to 50, just above doubly magic 78Ni. It is demonstrated that variations in key characteristics of the evolution, such as the lepton fraction, electron fraction, entropy, stellar density, and in-fall velocity are about 50% due to uncertainties in the electron-capture rates on nuclei in this region, although thousands of nuclei are included in the simulations. The present electron-capture rate estimates used for the nuclei in this high-sensitivity region of the chart of isotopes are primarily based on a simple approximation, and it is shown that the estimated rates are likely too high, by an order of magnitude or more. Electron-capture rates based on Gamow-Teller strength distributions calculated in microscopic theoretical models will be required to obtain better estimates. Gamow-Teller distributions extracted from charge-exchange experiments performed at intermediate energies serve to guide the development and benchmark the models. A previously compiled weak-rate library that is used in the astrophysical simulations was updated as part of the work presented here, by adding additional rate tables for nuclei near stability for mass numbers between 60 and 110.
DEFF Research Database (Denmark)
Mailund, Thomas
The thesis describes the sweep-line method, a newly developed reduction method for alleviating the state explosion problem inherent in explicit-state state space exploration. The basic idea underlying the sweep-line method is, when calculating the state space, to recognise and delete states...... that are not reachable from the currently unprocessed states. Intuitively we drag a sweep-line through the state space with the invariant that all states behind the sweep-line have been processed and are unreachable from the states in front of the sweep-line. When calculating the state space of a system we iteratively...
Present state of HDTV coding in Japan and future prospect
Murakami, Hitomi
The development status of HDTV digital codecs in Japan is evaluated; several bit rate-reduction codecs have been developed for 1125 lines/60-field HDTV, and performance trials have been conducted through satellite and optical fiber links. Prospective development efforts will attempt to achieve more efficient coding schemes able to reduce the bit rate to as little as 45 Mbps, as well as to apply coding schemes to automated teller machine networks.
Recreation Search DNR State of Alaska Home Menu Parks Home Alaska State Trails Boating Safety Design and Home / Alaska State Trails Alaska State Trails Program Trails in the Spotlight Glacier Lake and Saddle Trails in Kachemak State Park Glacier Lake A Popular route joins the Saddle and Glacier Lake Trails. The
Nabi, Jameel-Un; Böyükata, Mahmut
2016-03-01
We investigate even-even nuclei in the A ∼ 70 mass region within the framework of the proton-neutron quasi-particle random phase approximation (pn-QRPA) and the interacting boson model-1 (IBM-1). Our work includes calculation of the energy spectra and the potential energy surfaces V (β , γ) of Zn, Ge, Se, Kr and Sr nuclei with the same proton and neutron number, N = Z. The parametrization of the IBM-1 Hamiltonian was performed for the calculation of the energy levels in the ground state bands. Geometric shape of the nuclei was predicted by plotting the potential energy surfaces V (β , γ) obtained from the IBM-1 Hamiltonian in the classical limit. The pn-QRPA model was later used to compute half-lives of the neutron-deficient nuclei which were found to be in very good agreement with the measured ones. The pn-QRPA model was also used to calculate the Gamow-Teller strength distributions and was found to be in decent agreement with the measured data. We further calculate the electron capture and positron decay rates for these N = Z waiting point (WP) nuclei in the stellar environment employing the pn-QRPA model. For the rp-process conditions, our total weak rates are within a factor two compared with the Skyrme HF +BCS +QRPA calculation. All calculated electron capture rates are comparable to the competing positron decay rates under rp-process conditions. Our study confirms the finding that electron capture rates form an integral part of the weak rates under rp-process conditions and should not be neglected in the nuclear network calculations.
Energy Technology Data Exchange (ETDEWEB)
Gaudefroy, L
2005-09-15
The study of the N=28 shell closure has been presented as well as its astrophysical implications. Moreover the structure of neutron rich nuclei around N=32/34 and 40 was studied. The N=28 shell closure has been studied trough the one neutron transfer reaction on {sup 44,46}Ar nuclei. Excitation energies of states in {sup 45,47}Ar nuclei have been obtained, as well as their angular momenta and spectroscopic factors. These results were used to show that N=28 is still a good magic number in the argon isotopic chain. We interpreted the evolution of the spin-orbit partner gaps in terms of the tensor monopolar proton-neutron interaction. Thanks to this latter, we showed it is not necessary to summon up a reduction of the intensity of the spin-orbit force in order to explain this evolution in N=29 isotopes from calcium to argon chains. The neutron capture rates on {sup 44,46}Ar have been determined thanks to the results of the transfer reaction. Their influence on the nucleosynthesis of {sup 46,48}Ca was studied. We proposed stellar conditions to account for the abnormal isotopic ratio observed in the Allende meteorite concerning {sup 46,48}Ca isotopes. The beta decay and gamma spectroscopy of neutron rich nuclei in the scandium to cobalt region has been studied. We showed that beta decay process is dominated by the {nu}f{sub 5/2} {yields} {pi}f{sub 7/2} Gamow-Teller transition. Moreover, we demonstrated that the {nu}g{sub 9/2} hinders this process in the studied nuclei, and influences their structure, by implying the existence of isomers. Our results show that N=34 is not a magic number in the titanium chain and the superior ones. (author)
State Traffic Safety Information
Department of Transportation — The State Traffic Safety Information (STSI) portal is part of the larger Fatality Analysis Reporting System (FARS) Encyclopedia. STSI provides state-by-state traffic...
State Transportation Statistics 2014
2014-12-15
The Bureau of Transportation Statistics (BTS) presents State Transportation Statistics 2014, a statistical profile of transportation in the 50 states and the District of Columbia. This is the 12th annual edition of State Transportation Statistics, a ...
Minnesota Department of Natural Resources — This data set is a collection of ArcView shapefiles (by park) of trails within statutory boundaries of individual MN State Parks, State Recreation Areas and State...
State Park Statutory Boundaries
Minnesota Department of Natural Resources — Legislative statutory boundaries for sixty six state parks, six state recreation areas, and eight state waysides. These data are derived principally from DNR's...
Minimally conscious state or cortically mediated state?
Naccache, Lionel
2018-04-01
Durable impairments of consciousness are currently classified in three main neurological categories: comatose state, vegetative state (also recently coined unresponsive wakefulness syndrome) and minimally conscious state. While the introduction of minimally conscious state, in 2002, was a major progress to help clinicians recognize complex non-reflexive behaviours in the absence of functional communication, it raises several problems. The most important issue related to minimally conscious state lies in its criteria: while behavioural definition of minimally conscious state lacks any direct evidence of patient's conscious content or conscious state, it includes the adjective 'conscious'. I discuss this major problem in this review and propose a novel interpretation of minimally conscious state: its criteria do not inform us about the potential residual consciousness of patients, but they do inform us with certainty about the presence of a cortically mediated state. Based on this constructive criticism review, I suggest three proposals aiming at improving the way we describe the subjective and cognitive state of non-communicating patients. In particular, I present a tentative new classification of impairments of consciousness that combines behavioural evidence with functional brain imaging data, in order to probe directly and univocally residual conscious processes.
Far infrared spectroscopy of solids. I. Impurity states in Al2O3. II. Electron-hole droplets in Ge
International Nuclear Information System (INIS)
Aurbauch, R.L.
1975-01-01
Far infrared Fourier transform spectroscopy was used to study the low lying vibronic states of Mn 3+ in Al 2 O 3 and the plasma absorption of electron-hole droplets in Ge. The transmission of Mn-doped samples of Al 2 O 3 was measured in the frequency range from 3 to 30 cm -1 in applied magnetic fields up to 50 kG. Absorption lines were observed due to both ground and excited state transitions. Polarization measurements established that these absorption lines were due to electric dipole transitions. Temperature dependence measurements were used to derive a level diagram for the low lying states of Mn 3+ . A phenomenological model based on an electronic Hamiltonian was developed which successfully describes the data. The empirically determined trigonal field and spin-orbit quenching parameters of this model are 0.7 and 0.1 respectively. This quenching is attributed to the dynamic Jahn--Teller interaction. The plasma absorption of small (α) electron-hole drops in Ge was measured in the frequency range from 30 to 300 cm -1 . The observed absorption is in good agreement with measurements by Vavilov and other workers. A theoretical model which includes both intraband and interband contributions to the dielectric constant in the Rayleigh limit of Mie theory is used to describe the observed lineshape. Measurements of plasma absorption of large (γ) drops in inhomogeneously stressed Ge were made in magnetic fields up to 50 kG. The lineshape at zero applied field was calculated in the large sphere limit of Mie theory including intraband terms and a zero-strain interband term. Qualitative agreement with experiment was obtained. The peak absorption shifted quadratically with applied magnetic field and the total plasma absorption increased. No oscillatory structure was observed in the field-dependence of the total absorption
State nuclear initiatives in the United States
International Nuclear Information System (INIS)
Strauss, P.L.; Stoiber, C.R.
1977-01-01
The paper deals with State nuclear initiatives regarding the role of nuclear power in the energy future of the United States. The question of whether and under what circumstances nuclear facilities should be used to generate electricity was put to the popular vote in several States in 1976. Some general principles of Federal-State relations are discussed with specific reference to nuclear regulations. The initiative mechanism itself is described as well as its legal form and background. The parallel developments in the State and Federal legislative consideration of nuclear issues is reviewed and the suggested reasons for the defeat of the proposals in the seven States concerned are discussed. Finally, the author draws some conclusions on the effects of the 1976 initiatives on future decision-making in the US on energy policy in general and nuclear power in particular. (NEA) [fr
Transcriptome States Reflect Imaging of Aging States.
Eckley, D Mark; Coletta, Christopher E; Orlov, Nikita V; Wilson, Mark A; Iser, Wendy; Bastian, Paul; Lehrmann, Elin; Zhang, Yonqing; Becker, Kevin G; Goldberg, Ilya G
2018-06-14
In this study, we describe a morphological biomarker that detects multiple discrete subpopulations (or "age-states") at several chronological ages in a population of nematodes (Caenorhabditis elegans). We determined the frequencies of three healthy adult states and the timing of the transitions between them across the lifespan. We used short-lived and long-lived strains to confirm the general applicability of the state classifier and to monitor state progression. This exploration revealed healthy and unhealthy states, the former being favored in long-lived strains and the latter showing delayed onset. Short-lived strains rapidly transitioned through the putative healthy state. We previously found that age-matched animals in different age-states have distinct transcriptome profiles. We isolated animals at the beginning and end of each identified state and performed microarray analysis (principal component analysis, relative sample to sample distance measurements, and gene set enrichment analysis). In some comparisons, chronologically identical individuals were farther apart than morphologically identical individuals isolated on different days. The age-state biomarker allowed assessment of aging in a novel manner, complementary to chronological age progression. We found hsp70 and some small heat shock protein genes are expressed later in adulthood, consistent with the proteostasis collapse model.
Tomography of nonclassical states
Bazrafkan, MR; Man'ko, [No Value
2003-01-01
A review of the symplectic tomography method is presented. Superpositions of different types of photon states are considered within the framework of the tomography approach. Such nonclassical photon states as even and odd coherent states, crystallized Schrodinger cat states, and other superposition
DEFF Research Database (Denmark)
Kaspersen, Lars Bo; Schmidt-Hansen, Ulrich
in corporatist theory. In particular, we draw upon a conceptualization of the state developed by Michael Mann and Eric Nordlinger's different forms of state autonomy. We propose a state-centered theoretical focus enabling us to grasp the role of the state in the dynamics of the corporatist system. In the second...... to the development of the `Danish model', but that these actors were often orchestrated by the state. At crucial moments the direction of these different actors was even determined by the state. In the first part of the article, it is argued that the state has been under-theorized and to some extent neglected...
International Nuclear Information System (INIS)
Inoue, J.; Ohtaka, K.
2004-01-01
We study virtual bound states in photonics, which are a vectorial extension of electron virtual bound states. The condition for these states is derived. It is found that the Mie resonant state which satisfies the condition that the size parameter is less than the angular momentum should be interpreted as a photon virtual bound state. In order to confirm the validity of the concept, we compare the photonic density of states, the width of which represents the lifetime of the photon virtual bound states, with numerical results
Cristol, Y
2013-01-01
Solid State Video Cameras reviews the state of the art in the field of solid-state television cameras as compiled from patent literature. Organized into 10 chapters, the book begins with the basic array types of solid-state imagers and appropriate read-out circuits and methods. Documents relating to improvement of picture quality, such as spurious signal suppression, uniformity correction, or resolution enhancement, are also cited. The last part considerssolid-state color cameras.
International Nuclear Information System (INIS)
Roa, Luis; Retamal, Juan Carlos; Saavedra, Carlos
2002-01-01
A proposal for a physical implementation of a quantum-state discrimination protocol using an ion in a linear trap is studied, where two nonorthogonal quantum states are codified using two electronic states of the ion. In addition, a protocol is given for discriminating superpositions of nonorthogonal entangled states between ions inside widely separated optical cavities. The discrimination protocol is extended to the case of N linearly independent nonorthogonal quantum states lying in a space of 2N-1 dimensions
Verification of hypergraph states
Morimae, Tomoyuki; Takeuchi, Yuki; Hayashi, Masahito
2017-12-01
Hypergraph states are generalizations of graph states where controlled-Z gates on edges are replaced with generalized controlled-Z gates on hyperedges. Hypergraph states have several advantages over graph states. For example, certain hypergraph states, such as the Union Jack states, are universal resource states for measurement-based quantum computing with only Pauli measurements, while graph state measurement-based quantum computing needs non-Clifford basis measurements. Furthermore, it is impossible to classically efficiently sample measurement results on hypergraph states unless the polynomial hierarchy collapses to the third level. Although several protocols have been proposed to verify graph states with only sequential single-qubit Pauli measurements, there was no verification method for hypergraph states. In this paper, we propose a method for verifying a certain class of hypergraph states with only sequential single-qubit Pauli measurements. Importantly, no i.i.d. property of samples is assumed in our protocol: any artificial entanglement among samples cannot fool the verifier. As applications of our protocol, we consider verified blind quantum computing with hypergraph states, and quantum computational supremacy demonstrations with hypergraph states.
Crystallized Schroedinger cat states
International Nuclear Information System (INIS)
Castanos, O.; Lopez-Pena, R.; Man'ko, V.I.
1995-01-01
Crystallized Schroedinger cat states (male and female) are introduced on the base of extension of group construction for the even and odd coherent states of the electromagnetic field oscillator. The Wigner and Q functions are calculated and some are plotted for C 2 , C 3 , C 4 , C 5 , C 3v Schroedinger cat states. Quadrature means and dispersions for these states are calculated and squeezing and correlation phenomena are studied. Photon distribution functions for these states are given explicitly and are plotted for several examples. A strong oscillatory behavior of the photon distribution function for some field amplitudes is found in the new type of states
Most energetic passive states.
Perarnau-Llobet, Martí; Hovhannisyan, Karen V; Huber, Marcus; Skrzypczyk, Paul; Tura, Jordi; Acín, Antonio
2015-10-01
Passive states are defined as those states that do not allow for work extraction in a cyclic (unitary) process. Within the set of passive states, thermal states are the most stable ones: they maximize the entropy for a given energy, and similarly they minimize the energy for a given entropy. Here we find the passive states lying in the other extreme, i.e., those that maximize the energy for a given entropy, which we show also minimize the entropy when the energy is fixed. These extremal properties make these states useful to obtain fundamental bounds for the thermodynamics of finite-dimensional quantum systems, which we show in several scenarios.
Lim, Edward C
1982-01-01
Excited States, Volume 6 is a collection of papers that discusses the excited states of molecules. The first paper discusses the linear polyene electronic structure and potential surfaces, considering both the theoretical and experimental approaches in such electronic states. This paper also reviews the theory of electronic structure and cites some experimental techniques on polyene excitations, polyene spectroscopic phenomenology, and those involving higher states of polyenes and their triplet states. Examples of these experimental studies of excited states involve the high-resolution one-pho
Drug Poisoning Mortality by State: United States
U.S. Department of Health & Human Services — This dataset describes drug poisoning deaths at the U.S. and state level by selected demographic characteristics, and includes age-adjusted death rates for drug...
The Welfare State vs. the Redistributive State.
Plattner, Marc F.
1979-01-01
While the principles of progressive taxation and the welfare state have come to be almost universally accepted, it would be a serious error to infer that American policy has ever embraced the idea of income redistribution. (Author)
State diagrams of tokamaks and state transitions
International Nuclear Information System (INIS)
Minardi, E.
1992-01-01
In a simple one-fluid cylindrical model of transport and of dissipative effects, the family of the magnetic states of the Tokamak which correspond to a vanishing entropy production in the confinement region is characterized by a define relation or ''state equation'' involving the relevant parameters of the discharge. An investigation is made as to how the entropy production changes when the current density profile is rearranged by a perturbation which conserves the poloidal magnetic flux. It is shown that for a sufficiently short time interval, that is to say t 2 E τ s where τ E is the energy confinement time and τ s is the resistive time, neighbouring bifurcating equilibria exist which can be reached with a flux-conserving transition and with increase of the magnetic entropy. The family of these new states can also be characterized by a state equation involving the relevant discharge parameters. When the state equations of the two families are simultaneously satisfied by the same set of parameter values, a flux-conserving, entropy-increasing transition may take place between states of the two families. The modifications of the current density and of the temperature profiles involved in the transition and the conditions that the discharge parameters should satisfy in order that the transition could occur are investigated. (author)
Kansas Data Access and Support Center — This dataset is a single centerline highway network representation of the 10,000 miles Kansas State Highway System (Interstate, U.S., and Kansas routes). The state...
C. Spechler, Martin; Ahrens, Joachim; Hoen, Herman W.
2017-01-01
The book specifies the type of economic system that has arisen in Central Asian. It presents three types of state-capitalism established in the former Soviet Union states in Eurasia - crony, dual sector, and predatory capitalism.
... and age-adjusted death rates from unintentional injuries/accidents. Stroke Mortality by State, 2013 - Number of deaths and age-adjusted death rates from cerebrovascular disease. Alzheimer's Disease Mortality by State, 2013 - Number ...
Complications and Deaths - State
U.S. Department of Health & Human Services — Complications and deaths - state data. This data set includes state-level data for the hip/knee complication measure, the Agency for Healthcare Research and Quality...
Complications and Deaths - State
U.S. Department of Health & Human Services — Complications and deaths - state data. This data set includes state-level data for the hip/knee complication measure, the CMS Patient Safety Indicators, and 30-day...
California Natural Resource Agency — State Water Project District boundaries are areas where state contracts provide water to the district in California. This database is designed as a regions polygon...
State Program Integrity Reviews
U.S. Department of Health & Human Services — State program integrity reviews play a critical role in how CMS provides effective support and assistance to states in their efforts to combat provider fraud and...
Malaria Treatment (United States)
... Providers, Emergency Consultations, and General Public. Contact Us Malaria Treatment (United States) Recommend on Facebook Tweet Share Compartir Treatment of Malaria: Guidelines For Clinicians (United States) Download PDF version ...
U.S. Department of Health & Human Services — Payment for heart attack patients measure – state data. This data set includes state-level data for payments associated with a 30-day episode of care for heart...
State Transportation Statistics 2010
2011-09-14
The Bureau of Transportation Statistics (BTS), a part of DOTs Research and Innovative Technology Administration (RITA), presents State Transportation Statistics 2010, a statistical profile of transportation in the 50 states and the District of Col...
State transportation statistics 2009
2009-01-01
The Bureau of Transportation Statistics (BTS), a part of DOTs Research and : Innovative Technology Administration (RITA), presents State Transportation : Statistics 2009, a statistical profile of transportation in the 50 states and the : District ...
State Transportation Statistics 2011
2012-08-08
The Bureau of Transportation Statistics (BTS), a part of DOTs Research and Innovative Technology Administration (RITA), presents State Transportation Statistics 2011, a statistical profile of transportation in the 50 states and the District of Col...
International Nuclear Information System (INIS)
Aron, D.L.
1985-06-01
New data are presented for the 26 Mg(p,n) 26 Al reaction at E/sub p/ = 19.12 and 24.97 MeV, for the 54 Fe(p,n) 54 Co reaction at E/sub p/ = 17.20, 18.60, and 24.60 MeV, and for the 56 Fe(p,n) 56 Co reaction at E/sub p/ = 19.12 and 24.59 MeV. Data were taken with the LLNL Cyclograaff at 16 angles from 3.5 0 to 159.0 0 . A large detector at 23.8 0 with a long neutron flight path collected high resolution spectra. This large detector also collected separate 0 0 high resolution data on the 26 Mg and 56 Fe(p,n) reactions at E/sub p/ = 19 MeV. Absolute differential (p,n) cross sections were extracted for 1 + states in 26 Al, 54 Co, and 56 Co, for the 0 + isobaric analong state (IAS) in 54 Co and 56 Co, for a 2 + state in each residual nucleus, and for the 0.199 MeV 7 + state of 54 Co. No new experimental states were identified. Only relative cross sections were extracted at 0 0 . Experimental angle-integrated cross sections were obtained for all but one state. DWBA79 was used, with the G-matrix effective nucleon-nucleon interaction of Bertsch et al. (with the central triplet-odd component V/sub to/ = O) and the Livermore shell model wave functions to calculate differential (p,n) cross sections to 1 + states and to the 54 Co and 56 Co IAS. Normalization of the DWBA angle-integrated cross sections to measurements for the 54 Co and 56 Co IAS (at E/sub p/ = 24.6 MeV) yielded the renormalized V/sub tau/ = 21.4 +- 2.1 MeV. Normalization of the DWBA angle-integrated cross sections to measurements for the 24.6 MeV 54 Co and 56 Co 1 + states, coupled with the normalization of the wave functions to previously experimentally determined GT strength, yield the renormalized V/sub sigmatau/ = 12.3 +- 1.2 MeV. The experimental Gamow-Teller strength B(GT)/sub exp./ of the T = 1 26 Al state at 9.44 MeV was found to be 0.69; B(GT)/sub exp/ of the T = 1 26 Al state at 10.47 MeV was found to be 0.39
International Nuclear Information System (INIS)
Chattopadhyay, Anjan
2012-01-01
Ab initio-based configuration interaction studies on RbHe and He–Rb–He have explored some key features of the low-lying electronic states of these van der Waals systems. The radiative lifetime of the Rb*He exciplex has been calculated to be around 24.5 ns, which is slightly higher than the HeRb*He lifetime (∼20 ns) and lower than the atomic fluorescence lifetime of Rb, by roughly 3.5 ns. Better exciplex stability of the symmetric triatomic system is evidenced by its higher binding energy value in comparison to the diatomic system by a substantial margin. BSSE-corrected spin–orbit calculations of RbHe have predicted a potential barrier of the 1 2 Π 1/2 state with a height of 15 cm −1 and width of 2.57 Å. The 2 Π u state of the triatomic molecule shows a conical intersection of its Renner–Teller components (1 2 A 1 and 1 2 B 2 ) near a 99° bond angle along the bending path. Their unstable higher excited states (1 2 Σ + 1/2 or 1 2 Σ + g, 1/2 ) can trigger the pumping of the blue side of the ns 2 S 1/2 → np 2 P 3/2 transition, and this may eventually lead to the np 2 P 1/2 →ns 2 S 1/2 lasing transition. The broad fluorescence band with a peak near 11 900 cm −1 is found to arise from the 1 2 Π 3/2 –X 2 Σ + 1/2 transition of RbHe. (paper)
7 CFR 1220.615 - State and United States.
2010-01-01
... 7 Agriculture 10 2010-01-01 2010-01-01 false State and United States. 1220.615 Section 1220.615... CONSUMER INFORMATION Procedures To Request a Referendum Definitions § 1220.615 State and United States. State and United States include the 50 States of the United States of America, the District of Columbia...
7 CFR 1220.129 - State and United States.
2010-01-01
... 7 Agriculture 10 2010-01-01 2010-01-01 false State and United States. 1220.129 Section 1220.129... CONSUMER INFORMATION Soybean Promotion and Research Order Definitions § 1220.129 State and United States. The terms State and United States include the 50 States of the United States of America, the District...
7 CFR 1209.21 - State and United States.
2010-01-01
... 7 Agriculture 10 2010-01-01 2010-01-01 false State and United States. 1209.21 Section 1209.21... Definitions § 1209.21 State and United States. (a) State means any of the several States, the District of Columbia, and the Commonwealth of Puerto Rico. (b) United States means collectively the several States of...
Changing State Digital Libraries
Pappas, Marjorie L.
2006-01-01
Research has shown that state virtual or digital libraries are evolving into websites that are loaded with free resources, subscription databases, and instructional tools. In this article, the author explores these evolving libraries based on the following questions: (1) How user-friendly are the state digital libraries?; (2) How do state digital…
Solid state radiation dosimetry
International Nuclear Information System (INIS)
Moran, P.R.
1976-01-01
Important recent developments provide accurate, sensitive, and reliable radiation measurements by using solid state radiation dosimetry methods. A review of the basic phenomena, devices, practical limitations, and categories of solid state methods is presented. The primary focus is upon the general physics underlying radiation measurements with solid state devices
Buiren, K.; Brouwer, E.
2010-01-01
From economic theory we derive a set of hypotheses on the determination of state aid. Econometric analysis on EU state aid panel data is carried out to test whether the determinants we expect on the basis of theory, correspond to the occurrence of state aid in practice in the EU. We find that
Matrix product state description of Halperin states
Crépel, V.; Estienne, B.; Bernevig, B. A.; Lecheminant, P.; Regnault, N.
2018-04-01
Many fractional quantum Hall states can be expressed as a correlator of a given conformal field theory used to describe their edge physics. As a consequence, these states admit an economical representation as an exact matrix product state (MPS) that was extensively studied for the systems without any spin or any other internal degrees of freedom. In that case, the correlators are built from a single electronic operator, which is primary with respect to the underlying conformal field theory. We generalize this construction to the archetype of Abelian multicomponent fractional quantum Hall wave functions, the Halperin states. These can be written as conformal blocks involving multiple electronic operators and we explicitly derive their exact MPS representation. In particular, we deal with the caveat of the full wave-function symmetry and show that any additional SU(2) symmetry is preserved by the natural MPS truncation scheme provided by the conformal dimension. We use our method to characterize the topological order of the Halperin states by extracting the topological entanglement entropy. We also evaluate their bulk correlation lengths, which are compared to plasma analogy arguments.
Remote state preparation through hyperentangled atomic states
Nawaz, Mehwish; ul-Islam, Rameez-; Ikram, Manzoor
2018-04-01
Hyperentangled states have enhanced channel capacity in quantum processing and have yielded` evident increased communication speed in quantum informatics as a consequence of excessively high information content coded over each quantum entity. In the present article, we intend to demonstrate this fact by utilizing atomic states simultaneously entangled both in internal as well as external degrees of freedom, i.e. the de Broglie motion for remote state preparation (RSP). The results clearly demonstrate that we can efficiently communicate two bit information while manipulating only a single quantum subsystem. The states are prepared and manipulated using atomic Bragg diffraction as well as Ramsey interferometry, both of which are now considered as standard, state of the art tools based on cavity quantum electrodynamics. Since atomic Bragg diffraction is a large interaction time regime and produces spatially well separated, decoherence resistant outputs, the schematics presented here for the RSP offer important perspectives on efficient detection as well as unambiguous information coding and readout. The article summarizes the experimental feasibility of the proposal, culminating with a brief discussion.
Furusawa, Akira
2015-01-01
This book explains what quantum states of light look like. Of special interest, a single photon state is explained by using a wave picture, showing that it corresponds to the complementarity of a quantum. Also explained is how light waves are created by photons, again corresponding to the complementarity of a quantum. The author shows how an optical wave is created by superposition of a "vacuum" and a single photon as a typical example. Moreover, squeezed states of light are explained as "longitudinal" waves of light and Schrödinger's cat states as macroscopic superposition states.
Kemeth, Felix P.; Haugland, Sindre W.; Krischer, Katharina
2018-05-01
Symmetry broken states arise naturally in oscillatory networks. In this Letter, we investigate chaotic attractors in an ensemble of four mean-coupled Stuart-Landau oscillators with two oscillators being synchronized. We report that these states with partially broken symmetry, so-called chimera states, have different setwise symmetries in the incoherent oscillators, and in particular, some are and some are not invariant under a permutation symmetry on average. This allows for a classification of different chimera states in small networks. We conclude our report with a discussion of related states in spatially extended systems, which seem to inherit the symmetry properties of their counterparts in small networks.
Generalized hypergeometric coherent states
International Nuclear Information System (INIS)
Appl, Thomas; Schiller, Diethard H
2004-01-01
We introduce a large class of holomorphic quantum states by choosing their normalization functions to be given by generalized hypergeometric functions. We call them generalized hypergeometric states in general, and generalized hypergeometric coherent states in particular, if they allow a resolution of unity. Depending on the domain of convergence of the generalized hypergeometric functions, we distinguish generalized hypergeometric states on the plane, the open unit disc and the unit circle. All states are eigenstates of suitably defined lowering operators. We then study their photon number statistics and phase properties as revealed by the Husimi and Pegg-Barnett phase distributions. On the basis of the generalized hypergeometric coherent states we introduce new analytic representations of arbitrary quantum states in Bargmann and Hardy spaces as well as generalized hypergeometric Husimi distributions and corresponding phase distributions
Superexcited states of molecules
International Nuclear Information System (INIS)
Nakamura, Hiroki; Takagi, Hidekazu.
1990-01-01
The report addresses the nature and major features of molecule's superexcited states, focusing on their involvement in dynamic processes. It also outlines the quantum defect theory which allows various processes involving these states to be treated in a unified way. The Rydberg state has close relation with an ionized state with a positive energy. The quantum defect theory interprets such relation. Specifically, the report first describes the quantum defect theory focusing on its basic principle. The multi-channel quantum defect theory is then outlined centering on how to describe a Rydberg-type superexcited state. Description of a dissociative double-electron excited state is also discussed. The quantum defect theory is based on the fact that the physics of the motion of a Rydberg electron vary with the region in the electron's coordinate space. Finally, various molecular processes that involve a superexcited state are addressed focusing on autoionization, photoionization, dissociative recombination and bonding ionization of diatomic molecules. (N.K.)
Qutrit magic state distillation
International Nuclear Information System (INIS)
Anwar, Hussain; Browne, Dan E; Campbell, Earl T
2012-01-01
Magic state distillation (MSD) is a purification protocol that plays an important role in fault-tolerant quantum computation. Repeated iteration of the steps of an MSD protocol generates pure single non-stabilizer states, or magic states, from multiple copies of a mixed resource state using stabilizer operations only. Thus mixed resource states promote the stabilizer operations to full universality. MSD was introduced for qubit-based quantum computation, but little has been known concerning MSD in higher-dimensional qudit-based computation. Here, we describe a general approach for studying MSD in higher dimensions. We use it to investigate the features of a qutrit MSD protocol based on the five-qutrit stabilizer code. We show that this protocol distils non-stabilizer magic states, and identify two types of states that are attractors of this iteration map. Finally, we show how these states may be converted, via stabilizer circuits alone, into a state suitable for state-injected implementation of a non-Clifford phase gate, enabling non-Clifford unitary computation. (paper)
State Technologies Advancement Collaborative
Energy Technology Data Exchange (ETDEWEB)
David S. Terry
2012-01-30
The U. S. Department of Energy (DOE), National Association of State Energy Officials (NASEO), and Association of State Energy Research and Technology Transfer Institutions (ASERTTI) signed an intergovernmental agreement on November 14, 2002, that allowed states and territories and the Federal Government to better collaborate on energy research, development, demonstration and deployment (RDD&D) projects. The agreement established the State Technologies Advancement Collaborative (STAC) which allowed the states and DOE to move RDD&D forward using an innovative competitive project selection and funding process. A cooperative agreement between DOE and NASEO served as the contracting instrument for this innovative federal-state partnership obligating funds from DOE's Office of Energy Efficiency and Renewable Energy and Office of Fossil Energy to plan, fund, and implement RDD&D projects that were consistent with the common priorities of the states and DOE. DOE's Golden Field Office provided Federal oversight and guidance for the STAC cooperative agreement. The STAC program was built on the foundation of prior Federal-State efforts to collaborate on and engage in joint planning for RDD&D. Although STAC builds on existing, successful programs, it is important to note that it was not intended to replace other successful joint DOE/State initiatives such as the State Energy Program or EERE Special Projects. Overall the STAC process was used to fund, through three competitive solicitations, 35 successful multi-state research, development, deployment, and demonstration projects with an overall average non-federal cost share of 43%. Twenty-two states were awarded at least one prime contract, and organizations in all 50 states and some territories were involved as subcontractors in at least one STAC project. Projects were funded in seven program areas: (1) Building Technologies, (2) Industrial Technologies, (3) Transportation Technologies, (4) Distributed Energy
Quantum State Engineering Via Coherent-State Superpositions
Janszky, Jozsef; Adam, P.; Szabo, S.; Domokos, P.
1996-01-01
The quantum interference between the two parts of the optical Schrodinger-cat state makes possible to construct a wide class of quantum states via discrete superpositions of coherent states. Even a small number of coherent states can approximate the given quantum states at a high accuracy when the distance between the coherent states is optimized, e. g. nearly perfect Fock state can be constructed by discrete superpositions of n + 1 coherent states lying in the vicinity of the vacuum state.
Energy Technology Data Exchange (ETDEWEB)
Viennot, David, E-mail: david.viennot@utinam.cnrs.fr; Aubourg, Lucile
2016-02-15
We study a theoretical model of closed quasi-hermitian chain of spins which exhibits quantum analogues of chimera states, i.e. long life classical states for which a part of an oscillator chain presents an ordered dynamics whereas another part presents a disordered dynamics. For the quantum analogue, the chimera behaviour deals with the entanglement between the spins of the chain. We discuss the entanglement properties, quantum chaos, quantum disorder and semi-classical similarity of our quantum chimera system. The quantum chimera concept is novel and induces new perspectives concerning the entanglement of multipartite systems. - Highlights: • We propose a spin chain model with long range couplings having purely quantum states similar to the classical chimera states. • The quantum chimera states are characterized by the coexistence of strongly entangled and non-entangled spins in the same chain. • The quantum chimera states present some characteristics of quantum chaos.
International Nuclear Information System (INIS)
Viennot, David; Aubourg, Lucile
2016-01-01
We study a theoretical model of closed quasi-hermitian chain of spins which exhibits quantum analogues of chimera states, i.e. long life classical states for which a part of an oscillator chain presents an ordered dynamics whereas another part presents a disordered dynamics. For the quantum analogue, the chimera behaviour deals with the entanglement between the spins of the chain. We discuss the entanglement properties, quantum chaos, quantum disorder and semi-classical similarity of our quantum chimera system. The quantum chimera concept is novel and induces new perspectives concerning the entanglement of multipartite systems. - Highlights: • We propose a spin chain model with long range couplings having purely quantum states similar to the classical chimera states. • The quantum chimera states are characterized by the coexistence of strongly entangled and non-entangled spins in the same chain. • The quantum chimera states present some characteristics of quantum chaos.
Muonium states in semiconductors
International Nuclear Information System (INIS)
Patterson, B.D.
1987-01-01
There is a brief summary of what is known about the muonium states isotropic, anisotropic and diamagnetic in diamond and zincblende semiconductors. The report deals with muonium spectroscopy, including the formation probabilities, hyperfine parameters and electronic g-factors of the states. The dynamics of the states is treated including a discussion of the transition from isotropic Mu to anisotropic Mu in diamond, temperature-dependent linewidthes in silicon and germanium and effects of daping and radiation damage
Theoretical solid state physics
International Nuclear Information System (INIS)
Anon.
1977-01-01
Research activities at ORNL in theoretical solid state physics are described. Topics covered include: surface studies; particle-solid interactions; electronic and magnetic properties; and lattice dynamics
Burns, Gerald
2013-01-01
Solid State Physics, International Edition covers the fundamentals and the advanced concepts of solid state physics. The book is comprised of 18 chapters that tackle a specific aspect of solid state physics. Chapters 1 to 3 discuss the symmetry aspects of crystalline solids, while Chapter 4 covers the application of X-rays in solid state science. Chapter 5 deals with the anisotropic character of crystals. Chapters 6 to 8 talk about the five common types of bonding in solids, while Chapters 9 and 10 cover the free electron theory and band theory. Chapters 11 and 12 discuss the effects of moveme
International Nuclear Information System (INIS)
Rae, W.D.M.; Merchant, A.C.
1993-01-01
We review clustering in light nuclei including molecular resonances in heavy ion reactions. In particular we study the systematics, paying special attention to the relationships between cluster states and superdeformed configurations. We emphasise the selection rules which govern the formation and decay of cluster states. We review some recent experimental results from Daresbury and elsewhere. In particular we report on the evidence for a 7-α chain state in 28 Si in experiments recently performed at the NSF, Daresbury. Finally we begin to address theoretically the important question of the lifetimes of cluster states as deduced from the experimental energy widths of the resonances. (Author)
International Nuclear Information System (INIS)
Ambruş, Victor E.; Winstanley, Elizabeth
2014-01-01
We revisit the definition of rotating thermal states for scalar and fermion fields in unbounded Minkowski space–time. For scalar fields such states are ill-defined everywhere, but for fermion fields an appropriate definition of the vacuum gives thermal states regular inside the speed-of-light surface. For a massless fermion field, we derive analytic expressions for the thermal expectation values of the fermion current and stress–energy tensor. These expressions may provide qualitative insights into the behaviour of thermal rotating states on more complex space–time geometries
Lim, Edward C
2013-01-01
Excited States, Volume 2 is a collection of papers that deals with molecules in the excited states. The book describes the geometries of molecules in the excited electronic states. One paper describes the geometries of a diatomic molecule and of polyatomic molecules; it also discusses the determination of the many excited state geometries of molecules with two, three, or four atoms by techniques similar to diatomic spectroscopy. Another paper introduces an ordered theory related to excitons in pure and mixed molecular crystals. This paper also presents some experimental data such as those invo
/Fishing License Get a Birth Certificate, Marriage License, etc. Alaska Permanent Fund Dividend Statewide Library Alaska Historical Society Alaska State Museum Sheldon Jackson Museum Industry Facts Agriculture
Energy Technology Data Exchange (ETDEWEB)
Palmer, Michael H., E-mail: m.h.palmer@ed.ac.uk; Ridley, Trevor, E-mail: tr01@staffmail.ed.ac.uk, E-mail: vronning@phys.au.dk, E-mail: nykj@phys.au.dk, E-mail: marcello.coreno@elettra.eu, E-mail: desimone@iom.cnr.it, E-mail: malgorzata.biczysko@shu.edu.cn, E-mail: alberto.baiardi@sns.it, E-mail: kipeters@wsu.edu [School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, Scotland (United Kingdom); Vrønning Hoffmann, Søren, E-mail: tr01@staffmail.ed.ac.uk, E-mail: vronning@phys.au.dk, E-mail: nykj@phys.au.dk, E-mail: marcello.coreno@elettra.eu, E-mail: desimone@iom.cnr.it, E-mail: malgorzata.biczysko@shu.edu.cn, E-mail: alberto.baiardi@sns.it, E-mail: kipeters@wsu.edu; Jones, Nykola C., E-mail: tr01@staffmail.ed.ac.uk, E-mail: vronning@phys.au.dk, E-mail: nykj@phys.au.dk, E-mail: marcello.coreno@elettra.eu, E-mail: desimone@iom.cnr.it, E-mail: malgorzata.biczysko@shu.edu.cn, E-mail: alberto.baiardi@sns.it, E-mail: kipeters@wsu.edu [ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Coreno, Marcello, E-mail: tr01@staffmail.ed.ac.uk, E-mail: vronning@phys.au.dk, E-mail: nykj@phys.au.dk, E-mail: marcello.coreno@elettra.eu, E-mail: desimone@iom.cnr.it, E-mail: malgorzata.biczysko@shu.edu.cn, E-mail: alberto.baiardi@sns.it, E-mail: kipeters@wsu.edu [CNR-ISM, Basovizza Area Science Park, 1-34149 Trieste (Italy); De Simone, Monica, E-mail: tr01@staffmail.ed.ac.uk, E-mail: vronning@phys.au.dk, E-mail: nykj@phys.au.dk, E-mail: marcello.coreno@elettra.eu, E-mail: desimone@iom.cnr.it, E-mail: malgorzata.biczysko@shu.edu.cn, E-mail: alberto.baiardi@sns.it, E-mail: kipeters@wsu.edu [CNR-IOM Laboratorio TASC, Trieste (Italy); Grazioli, Cesare [CNR-IOM Laboratorio TASC, Trieste (Italy); Department of Chemical and Pharmaceutical Sciences, University of Trieste, Trieste (Italy); Zhang, Teng [Department of Physics and Astronomy, University of Uppsala, Uppsala (Sweden); and others
2016-03-28
New photoelectron (PE) and ultra violet (UV) and vacuum UV (VUV) spectra have been obtained for chlorobenzene by synchrotron study with higher sensitivity and resolution than previous work and are subjected to detailed analysis. In addition, we report on the mass-resolved (2 + 1) resonance enhanced multiphoton ionization (REMPI) spectra of a jet-cooled sample. Both the VUV and REMPI spectra have enabled identification of a considerable number of Rydberg states for the first time. The use of ab initio calculations, which include both multi-reference multi-root doubles and singles configuration interaction (MRD-CI) and time dependent density functional theoretical (TDDFT) methods, has led to major advances in interpretation of the vibrational structure of the ionic and electronically excited states. Franck-Condon (FC) analyses of the PE spectra, including both hot and cold bands, indicate much more complex envelopes than previously thought. The sequence of ionic states can be best interpreted by our multi-configuration self-consistent field computations and also by comparison of the calculated vibrational structure of the B and C ionic states with experiment; these conclusions suggest that the leading sequence is the same as that of iodobenzene and bromobenzene, namely: X{sup 2}B{sub 1}(3b{sub 1}{sup −1}) < A{sup 2}A{sub 2}(1a{sub 2}{sup −1}) < B{sup 2}B{sub 2}(6b{sub 2}{sup −1}) < C{sup 2}B{sub 1}(2b{sub 1}{sup −1}). The absorption onset near 4.6 eV has been investigated using MRD-CI and TDDFT calculations; the principal component of this band is {sup 1}B{sub 2} and an interpretation based on the superposition of FC and Herzberg-Teller contributions has been performed. The other low-lying absorption band near 5.8 eV is dominated by a {sup 1}A{sub 1} state, but an underlying weak {sup 1}B{sub 1} state (πσ{sup ∗}) is also found. The strongest band in the VUV spectrum near 6.7 eV is poorly resolved and is analyzed in terms of two ππ{sup ∗} states of
Orthogonalization of correlated states
International Nuclear Information System (INIS)
Fantoni, S.; Pandharipande, V.R.
1988-01-01
A scheme for orthogonalizing correlated states while preserving the diagonal matrix elements of the Hamiltonian is developed. Conventional perturbation theory can be used with the orthonormal correlated basis obtained from this scheme. Advantages of using orthonormal correlated states in calculations of the response function and correlation energy are discussed
Investment Advisors Business Law Charitable Gaming Division of Banking & Securities Laws Relating to Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Government Jobs Federal Jobs Starting a Small Business Living Get a Driver License Get a Hunting
DEFF Research Database (Denmark)
Dahl, Hanne Marlene; Kantola, Johanna
2005-01-01
The article argues from a Nordic, feminist and post-structuralist position that feminism state theories need to be developed methodologically.......The article argues from a Nordic, feminist and post-structuralist position that feminism state theories need to be developed methodologically....
Maximally multipartite entangled states
Facchi, Paolo; Florio, Giuseppe; Parisi, Giorgio; Pascazio, Saverio
2008-06-01
We introduce the notion of maximally multipartite entangled states of n qubits as a generalization of the bipartite case. These pure states have a bipartite entanglement that does not depend on the bipartition and is maximal for all possible bipartitions. They are solutions of a minimization problem. Examples for small n are investigated, both analytically and numerically.
Directory of Open Access Journals (Sweden)
Christoph Wagner
2014-08-01
Full Text Available Formal reasoning about distributed algorithms (like Consensus typically requires to analyze global states in a traditional state-based style. This is in contrast to the traditional action-based reasoning of process calculi. Nevertheless, we use domain-specific variants of the latter, as they are convenient modeling languages in which the local code of processes can be programmed explicitly, with the local state information usually managed via parameter lists of process constants. However, domain-specific process calculi are often equipped with (unlabeled reduction semantics, building upon a rich and convenient notion of structural congruence. Unfortunately, the price for this convenience is that the analysis is cumbersome: the set of reachable states is modulo structural congruence, and the processes' state information is very hard to identify. We extract from congruence classes of reachable states individual state-informative representatives that we supply with a proper formal semantics. As a result, we can now freely switch between the process calculus terms and their representatives, and we can use the stateful representatives to perform assertional reasoning on process calculus models.
International Nuclear Information System (INIS)
Green, P.H.; Watson, D.M.
1989-08-01
This report contains brief discussions on work done in the Solid State Division of Oak Ridge National Laboratory. The topics covered are: Theoretical Solid State Physics; Neutron scattering; Physical properties of materials; The synthesis and characterization of materials; Ion beam and laser processing; and Structure of solids and surfaces
Energy Technology Data Exchange (ETDEWEB)
Green, P.H.; Watson, D.M. (eds.)
1989-08-01
This report contains brief discussions on work done in the Solid State Division of Oak Ridge National Laboratory. The topics covered are: Theoretical Solid State Physics; Neutron scattering; Physical properties of materials; The synthesis and characterization of materials; Ion beam and laser processing; and Structure of solids and surfaces. (LSP)
International Nuclear Information System (INIS)
Reuther, H.
1976-11-01
This paper gives a survey of the present state of the development and the application of solid state track detectors. The fundamentals of the physical and chemical processes of the track formation and development are explained, the different detector materials and their registration characteristics are mentioned, the possibilities of the experimental practice and the most variable applications are discussed. (author)
Bruinessen, M.M. van
2002-01-01
At most times, Kurdish society has existed at the periphery of, and functioned as a buffer between, two or more neighbouring states. From c. 1500 until the First World War, the relevant states were the Ottoman Empire in the west and Safavid, later Qajar Iran in the east (with Russia and the
DEFF Research Database (Denmark)
This book offers an accessible, coherent and informative analysis of contemporary and future foreign policy challenges facing small states in Europe.......This book offers an accessible, coherent and informative analysis of contemporary and future foreign policy challenges facing small states in Europe....
Dissociative State and Competence
Directory of Open Access Journals (Sweden)
Yu-Ju Lin
2007-10-01
Full Text Available This report presents the results of forensic evaluation of the civil competence of a case of alleged dissociative identity disorder (DID and discusses whether such dissociative states substantially jeopardize civil competence. A 40-year-old woman claimed that she had had many personalities since her college days. From the age of 37 to 40, she shopped excessively, which left her with millions of dollars of debt. She ascribed her shopping to a certain identity state, over which she had no control. (In this article, we use the term identity state to replace personality as an objective description of a mental state. She thus raised the petition of civil incompetence. During the forensic evaluation, it was found that the identity states were relatively stable and mutually aware of each other. The switch into another identity state was sometimes under voluntary control. The subject showed consistency and continuity in behavioral patterns across the different identity states, and no matter which identity state she was in, there was no evidence of impairment in her factual knowledge of social situations and her capacity for managing personal affairs. We hence concluded that she was civilly competent despite the claimed DID. Considering that the existence and diagnosis of DID are still under dispute and a diagnosis of DID alone is not sufficient to interdict a person's civil right, important clinical and forensic issues remain to be answered.
DEFF Research Database (Denmark)
Obinger, Herbert; Starke, Peter
2014-01-01
This paper describes welfare state transformation in OECD countries since the 1970s against the background of the post-war settlement. Relying on quantitative macro-data and qualitative information from the literature, we show that welfare states have con-verged, especially regarding various...