| 1. |
- Schael, S, et al.
(author)
-
Precision electroweak measurements on the Z resonance
- 2006
-
In: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
-
Research review (peer-reviewed)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Mason, P, et al.
(author)
-
Octupole signatures in Ba-124,Ba-125
- 2005
-
In: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 31:10, s. S1729-S1733
-
Journal article (peer-reviewed)abstract
- The gamma decay of the nuclei Ba-121,Ba-125 has been investigated with the EUROBALL array, using the reaction Ni-64+Ni-64 at E-beam = 255 and 261 MeV. Six new E1 transitions have been found in the nucleus Ba-125, suggesting a significant role of octupole correlations in the origin of its parity doublets. The J(pi) = 3(-) level of the nucleus Ba-124 has been identified for the first time. Its excitation energy is in very good agreement with a prediction based on a microscopic model including octupole interactions.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Basu, Anwesha, et al.
(author)
-
Highly deformed band structures due to core excitations in Xe 123
- 2021
-
In: Physical Review C. - 2469-9985. ; 103:1
-
Journal article (peer-reviewed)abstract
- High-spin states in Xe123 were populated in the Se80(Ca48, 5n)Xe123 reaction at a beam energy of 207 MeV. γ-ray coincidence events were recorded with the Gammasphere spectrometer. Four new high-spin bands have been discovered in this nucleus. The bands are compared with those calculated within the framework of cranked Nilsson-Strutinsky and cranked Nilsson-Strutinsky-Bogoliubov models. It is concluded that the configurations of the bands involve two-proton excitations across the Z=50 as well as excitation of neutrons across the N=82 shell gaps resulting in a large deformation, 2≈0.30 and γ≈5°C.
|
|
| 8. |
- Riley, M A, et al.
(author)
-
Beyond band termination in Er-157 and the search for wobbling excitations in strongly deformed Hf-174
- 2005
-
In: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 31:10, s. 1735-1740
-
Journal article (peer-reviewed)abstract
- High-spin terminating bands in heavy nuclei were first identified in nuclei around Er-158(90). While examples of special terminating states have been identified in a number of erbium isotopes, almost nothing is known about the states lying beyond band termination. In the present work the high-spin structure of Er-157 has been studied using the Gammasphere spectrometer. The subject of triaxial superdeformation and 'wobbling' modes in Lu nuclei has rightly attracted a great deal of attention. Very recently, four strongly or superdeformed (SD) sequences have been observed in Hf-174 and ultimate cranker calculations predict, such structures may have significant triaxial deformation. We have performed two experiments in an attempt to verify the possible triaxial nature of these bands. A lifetime measurement was performed to confirm the large (and similar) deformation of the bands. In addition, a high-statistics, thin-target experiment was run to search for linking transitions between the SD bands and possible wobbling modes.
|
|
| 9. |
- Riley, M. A., et al.
(author)
-
Observation of states beyond band termination in Er-156,Er-157,Er-158 and strongly deformed structures in Hf-173,Hf-174,Hf-175
- 2006
-
In: Physica Scripta. - 0031-8949. ; T125, s. 123-126
-
Journal article (peer-reviewed)abstract
- High-spin terminating bands in heavy nuclei were first identified in nuclei around Er-158(90). While examples of terminating states have been identified in a number of erbium isotopes, almost nothing is known about the states lying beyond band termination. In the present work, the high-spin structure of Er-156,Er-157,Er-158 has been studied using the Gammasphere spectrometer. The subject of triaxial superdeformation and 'wobbling' modes in Lu nuclei has rightly attracted a great deal of attention. Very recently four strongly or superdeformed (SD) sequences have been observed in Hf-174, and cranking calculations using the Ultimate Cranker code predict that such structures may have significant triaxial deformation. We have performed two experiments in an attempt to verify the possible triaxial nature of these bands. A lifetime measurement was performed to confirm the large (and similar) deformation of the bands. In addition, a high-statistics, thin-target experiment took place to search for linking transitions between the SD bands, possible wobbling modes, and new SD band structures.
|
|
| 10. |
- Yadav, R. B., et al.
(author)
-
Identification of triaxial strongly deformed bands in Hf-168
- 2008
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 78:4
-
Journal article (peer-reviewed)abstract
- Possible decay pathways associated with three candidates for triaxial strongly deformed (TSD) bands in Hf-168 have been investigated. The spin and excitation energy of the strongest band, TSD1, were determined approximately based on gamma-ray coincidence relationships. Discrete links were established for the second band. The overall agreement between the observed properties of the bands and cranking calculations using the ULTIMATE CRANKER code provides strong support for an interpretation where band TSD1 is associated with a TSD minimum, (epsilon(2),gamma)similar to(0.43,20(degrees)), involving the pi(i(13/2))(2) and the nu(j(15/2)) high-j orbitals. This constitutes the first identification of a TSD band in Hf isotopes, which has been long-predicted by theoretical studies. The second band is understood as being associated with a near-prolate shape and a deformation enhanced with respect to the normal deformed bands. It is proposed to be built on the pi(i(13/2)h(9/2))circle times nu(i(13/2))(2) configuration.
|
|
| 11. |
- Bhowal, S., et al.
(author)
-
Development of collective structures over noncollective excitations in Nd-139
- 2011
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 84:2
-
Journal article (peer-reviewed)abstract
- High-spin states in Nd-139 were investigated using the reaction Zr-96(Ca-48,5n) at a beam energy of 195 MeV and gamma-ray coincidences were acquired with the Euroball spectrometer. Apart from several dipole bands at medium excitation energy, three quadrupole bands have been observed at high spin. Linking transitions connecting two of the high-spin bands to low-energy states have been observed. Calculations based on the cranked-Nilsson-Strutinsky formalism have been used to assign configurations for the high-spin quadrupole bands.
|
|
| 12. |
- Petrache, C. M., et al.
(author)
-
Triaxiality at high spins in Nd nuclei
- 2006
-
In: Physica Scripta. - 0031-8949. ; T125, s. 212-213
-
Journal article (peer-reviewed)abstract
- The level structure of Nd-140(80) has been established up to spin 48 by in-beam gamma-ray spectroscopy using the Zr-96(Ca-48, 4n) reaction. High-fold gamma-ray coincidences were measured with the EUROBALL spectrometer. Twelve new rotational bands have been discovered at high spins, showing the change from a spherical single-particle behaviour at low spins to a deformed regime with stable triaxiality at high spins. Possible configurations are assigned to the observed bands on the basis of configuration-dependent cranked Nilsson-Strutinsky calculations.
|
|
| 13. |
- Basu, Anwesha, et al.
(author)
-
Evolution of collective and noncollective structures in Xe 123
- 2020
-
In: Physical Review C. - 2469-9985. ; 101:2
-
Journal article (peer-reviewed)abstract
- An experiment involving a heavy-ion-induced fusion-evaporation reaction was carried out where high-spin states of Xe123 were populated in the Se80(Ca48,5n)Xe123 reaction at 207 MeV beam energy. Gamma-ray coincidence events were recorded with the Gammasphere Ge detector array. The previously known level scheme was confirmed and enhanced with the addition of five new band structures and several interband transitions. Cranked Nilsson-Strutinsky (CNS) calculations were performed and compared with the experimental results in order to assign configurations to the bands.
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
- Nag, Somnath, et al.
(author)
-
Observation of high-spin bands with large moments of inertia in Xe 124
- 2016
-
In: Physical Review C - Nuclear Physics. - 0556-2813. ; 94:3
-
Journal article (peer-reviewed)abstract
- High-spin states in Xe124 have been populated using the Se80(Ca48,4n) reaction at a beam energy of 207 MeV and high-multiplicity, γ-ray coincidence events were measured using the Gammasphere spectrometer. Six high-spin bands with large moments of inertia, similar to those observed in neighboring nuclei, have been observed. The experimental results are compared with calculations within the framework of the cranked Nilsson-Strutinsky model. It is suggested that the configurations of the bands involve excitations of protons across the Z=50 shell gap coupled to neutrons within the N=50-82 shell or excited across the N=82 shell closure.
|
|
| 17. |
- Nag, Somnath, et al.
(author)
-
Revised level structure of Te-120
- 2014
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 90:3
-
Journal article (peer-reviewed)abstract
- The level scheme of the nucleus Te-120, populated in the reaction Se-80(Ca-48, alpha 4n), was reinvestigated using gamma-ray coincidence data measured with the Gammasphere spectrometer. Previously, five high-spin rotational bands were discovered in this nucleus. The present reinvestigation revealed that the decay of band b1 is more complex than suggested in the earlier work and that it cannot be uniquely determined. Furthermore, a number of new transitions are added to the level scheme. The implications for the spin assignments and excitation energies of the five bands and for comparisons with cranked Nilsson-Strutinsky calculations are discussed.
|
|
| 18. |
- Singh, Purnima, et al.
(author)
-
High-spin rotational bands in I-123
- 2012
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 86:6
-
Journal article (peer-reviewed)abstract
- High-spin states in I-123 were populated in the reaction Se-80(Ca-48,p4n)I-123 at a beam energy of 207 MeV and gamma-ray coincidence events were measured using the Gammasphere spectrometer. Three weakly populated, high-spin rotational bands have been discovered with characteristics similar to those of the long collective bands recently observed in other nuclei of this mass region. Configuration assignments are proposed based on calculations within the framework of the cranked Nilsson-Strutinsky approach. DOI: 10.1103/PhysRevC.86.067305
|
|
| 19. |
- Al-Khatib, A, et al.
(author)
-
Transition to non-collective states at high spin in Xe-124
- 2008
-
In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 36:1, s. 21-29
-
Journal article (peer-reviewed)abstract
- Excited states in Xe-124 were populated in the reaction Se-82(Ca-48, 6n) Xe-124 and gamma-ray coincidence relationships were measured with the Gammasphere spectrometer. Two new bands are observed and several of the previously known bands are extended in the high-as well as in the low-spin region. Two irregular high-spin structures are also added. The irregularities are a fingerprint of a transition from collective to non-collective behaviour. Configuration assignments to the new structures are proposed on the basis of systematics and by comparing experimental properties with calculations within the framework of the cranking model.
|
|
| 20. |
|
|
| 21. |
- Jensen, DR, et al.
(author)
-
Coexisting wobbling and quasiparticle excitations in the triaxial potential well of Lu-163
- 2004
-
In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 19:2, s. 173-185
-
Journal article (peer-reviewed)abstract
- High-spin states of the nucleus Lu-163 have been populated through the fusion-evaporation reaction La-139(Si-29, 5n) with a beam energy of 157 MeV. In addition to the two lowest excited triaxial strongly deformed (TSD) bands, recently interpreted as one- and two-phonon wobbling excitations, a third excited TSD band has been firmly established decaying to the yrast TSD band. The assignment of this band as a three-quasiparticle band shows together with the normal deformed (ND) level scheme the presence not only of shape coexistence between ND and TSD structures, but also an interplay of wobbling and quasiparticle excitations in the triaxial strongly deformed potential well of Lu-163.
|
|
| 22. |
- Marsh, J. C., et al.
(author)
-
Identification of triaxial strongly deformed bands in Hf-164
- 2013
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 88:4
-
Journal article (peer-reviewed)abstract
- Two new rotational bands of distinct character have been identified in Hf-164. They are suggested to correspond to the long-anticipated triaxial strongly deformed (TSD) bands predicted by theoretical studies. The bands have been linked to known states, and the level spins and energies could be determined. The bands are also substantially stronger in intensity and are located at lower spins than the previously observed TSD bands in Hf-168, hereby making Hf-164 the best even-even system so far for the study of TSD structures in the A similar to 160 mass region. Cranking calculations based on the modified-oscillator model suggest that the bands are associated with four-quasiparticle configurations that involve high-j intruder (i(13/2))(2) proton orbitals.
|
|
| 23. |
- Nag, Somnath, et al.
(author)
-
Collective and noncollective excitations in Te-122
- 2013
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 88:4
-
Journal article (peer-reviewed)abstract
- High-spin states in Te-122 were populated in the reaction Se-82(Ca-48, alpha 4n) Te-122 at a beam energy of 200 MeV and gamma-ray coincidences weremeasured with the Gammasphere spectrometer. The previously known level scheme was extended to considerably higher spin. Maximally aligned states and several high-energy transitions feeding into some of these levels were observed. In addition, seven collective high-spin bands were discovered for the first time in this nucleus. The experimental results are compared with cranked Nilsson-Strutinsky model calculations and possible configuration assignments to the new high-spin structures are discussed.
|
|
| 24. |
- Neusser, A, et al.
(author)
-
Superdeformed band at very high spin in Nd-140
- 2004
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 70:6
-
Journal article (peer-reviewed)abstract
- A new high-spin superdeformed band has been discovered in Nd-140(60)80. It was populated in the Zr-96(Ca-48,4n) reaction and investigated using the EUROBALL gamma-ray spectrometer array. The band is observed in the approximate spin range of I=36 to 66. It is associated with shell gaps around Z=60 and at N=80 at large deformation. These gaps produce a pronounced minimum in the calculated total Routhian surfaces at a quadrupole deformation of epsilon(2)=0.45. The new band which lies between the high-deformation bands in the Aapproximate to130 region and the superdeformed bands in Aapproximate to150 nuclei provides insight into the development of the deformation between these two regions. Two possible configurations are suggested involving four neutrons of i(13/2) origin (nu6(4)) and either six protons of h(11/2)/h(9/2) origin (pi5(6)) or five protons of h(11/2)/h(9/2) and one of i(13/2) origin (pi5(5)6(1)).
|
|
| 25. |
- Singh, Purnima, et al.
(author)
-
Highly deformed high-spin band in I-125
- 2011
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 84:2
-
Journal article (peer-reviewed)abstract
- High-spin states in I-125 have been investigated using the reaction Se-82(Ca-48, p4n) at a beam energy of 200 MeV and gamma-ray coincidence events were detected using the Gammasphere spectrometer. A deformed rotational band, extending up to I-pi = 95/2(-), was observed for the first time in a heavier odd-A iodine nucleus. The characteristics of the band are very similar to those of the highly deformed bands observed recently in neighboring nuclei and it is essentially identical to one of the previously known bands in Xe-126. The experimental results are compared to cranked Nilsson-Strutinsky calculations and possible configurations for the band are discussed.
|
|
| 26. |
- Singh, Purnima, et al.
(author)
-
Noncollective aligned and antialigned states in I-125
- 2010
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 82:3
-
Journal article (peer-reviewed)abstract
- High-spin states in I-125 were populated using the reaction Se-82(Ca-48, p4n) at a beam energy of 200 MeV and gamma-ray coincidence events were acquired with the Gammasphere spectrometer. The level scheme of I-125 was extended considerably. In particular, maximally aligned states involving all eleven particles outside the Sn-114 core were observed. Comparison with cranked Nilsson-Strutinsky calculations suggests that three of these states are the final I-max states in terminating bands with all spin vectors aligned along a common axis. In two of these, one spin vector is antialigned and points in the opposite direction. In one of the states two spin vectors are antialigned. This is the first observation of a state with such a structure.
|
|
| 27. |
- Zerrouki, T., et al.
(author)
-
Shape evolution and magnetic rotation in Nd-141
- 2015
-
In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 51:4
-
Journal article (peer-reviewed)abstract
- The high-spin states in Nd-141 were investigated using the Zr-96(Ca-48, 3n) reaction and the EU-ROBALL array. The level scheme has been extended up to an excitation energy of around 16MeV and spin 81/2. Two new bands of dipole transitions and three bands presumably of quadrupole transitions were identified and their connections to low-lying states were established. Cranked Nilsson-Strutinsky and tilted axis cranking calculations are combined in the interpretation of the observed dipole bands. The high-spin bands with assigned quadrupole transitions are interpreted as triaxial bands, while the dipole bands appear in the calculations to exhibit a shape evolution from low-deformation triaxial to spherical shape. They can be classified as magnetic rotation, with transition probabilities that show the characteristic decrease with angular momentum caused by the shears mechanism.
|
|
| 28. |
|
|
| 29. |
- Herskind, B., et al.
(author)
-
Charged particle feeding of hyperdeformed nuclei in the A=118-126 region
- 2006
-
In: Physica Scripta. - 0031-8949 .- 1402-4896. ; T125, s. 108-114
-
Journal article (peer-reviewed)abstract
- A breakthrough was recently obtained in the analysis of the so-called Hyper-Long-HyperDeformed (HLHD) experiment made at the EUROBALL-IV gamma-detector array (EB). The Ni-64 + Ni-64 double right arrow Ba-128* fusion reaction was studied at E-beam = 255 and 261 MeV, reaching the highest angular momentum that the compound nuclei can accommodate. To date no discrete HD rotational bands have been identified. However, rotational patterns in the form of ridge-structures in three-dimensional (3D) rotational mapped spectra are identified with dynamic moments of inertia J((2)) ranging from 71 to 111h(2) MeV-1 in 12 different nuclei selected by charged particle- and/or gamma-gating. The four nuclei, Te-118, Cs-124, Cs-125 and Xe-124 found with moment of inertia J((2)) >= 100h(2) MeV-1, are most likely hyperdeformed, the remaining nuclei with smaller values of J((2)), are considered to be superdeformed, in qualitative agreement with recent theoretical calculations.
|
|
| 30. |
- Jensen, DR, et al.
(author)
-
Evidence for second-phonon nuclear wobbling
- 2002
-
In: Physical Review Letters. - 1079-7114. ; 89:14
-
Journal article (peer-reviewed)abstract
- The nucleus Lu-163 has been populated through the reaction La-139(Si-29,5n) with a beam energy of 157 MeV. Three triaxial, strongly deformed (TSD) bands have been observed with very similar rotational properties. The first excited TSD band has earlier been assigned as a one-phonon wobbling excitation built on the lowest-lying (yrast) TSD band. The large B(E2)(out)/B(E2)(in) value obtainable for one of four observed transitions between the second and first excited TSD bands is in good agreement with particle-rotor calculations for a two-phonon wobbling excitation.
|
|
| 31. |
- Leguillon, R., et al.
(author)
-
High-spin spectroscopy of Nd-140
- 2013
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 88:1
-
Journal article (peer-reviewed)abstract
- The population of the high-spin states in Nd-140 was investigated using the reaction Zr-96(Ca-48,4n). The results from two experiments, one with the EUROBALL array and one with the JUROGAM II + RITU + GREAT setup employing the recoil decay tagging technique, have been combined to develop a very detailed level scheme for Nd-140. Twelve bands of quadrupole transitions and eleven bands of dipole transitions were identified and their connections to low-lying states were established. Calculations using the cranked Nilsson-Strutinsky and the tilted axis cranking models were used to interpret the observed structures. The overall good agreement between the experimental results and the calculations assuming a triaxial shape of the nucleus strongly support the existence of a stable triaxial shape at high spins in this mass region.
|
|
| 32. |
|
|
| 33. |
- Schonwasser, G, et al.
(author)
-
Coexisting normal and triaxial superdeformed structures in Lu-165
- 2004
-
In: Nuclear Physics, Section A. - : Elsevier BV. - 0375-9474. ; 735:3-4, s. 393-424
-
Journal article (peer-reviewed)abstract
- High-spin states in Lu-165 were populated in the La-139(Si-30, 4n) reaction at a beam energy of 152 MeV and gamma-ray coincidences were measured with the EUROBALL spectrometer array. Nine new rotational bands were discovered, known band structures were considerably extended and many inter-band transitions were found. Structures with normal deformation coexist with bands associated with the strongly deformed triaxial energy minima found in calculations. Three of these triaxial bands form a family of wobbling excitations with phonon quanta n(w) = 0, 1 and 2. The wobbling mode is a unique signature of nuclear triaxiality. Configuration assignments are discussed for the observed band structures. An exchange of configuration between two of the new bands due to mixing is observed, resulting in different signature partnerships at low and high spins.
|
|
| 34. |
- Schonwasser, G, et al.
(author)
-
One- and two-phonon wobbling excitations in triaxial Lu-165
- 2003
-
In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 552:1-2, s. 9-16
-
Journal article (peer-reviewed)abstract
- High-spin states in Lu-165 have been investigated by in-beam gamma-ray coincidence spectroscopy using the EUROBALL spectrometer array. Two new excited rotational bands have been discovered with features similar to a previously known triaxial superdeformed band in that nucleus. Comparison of the decay pattern of these bands, in particular the unusually large E2 transition strength from the first excited to the yrast superdeformed band, to theoretical calculations shows that they belong to a family of wobbling excitations with phonon numbers n(w) = 0, 1 and 2. These results, together with evidence for nuclear wobbling in the neighbouring isotopes Lu-163 and Lu-167, firmly establish this mode of excitation in the A = 165 mass region. The observation of wobbling is a unique signature of stable nuclear triaxiality. (C) 2002 Elsevier Science B.V. All rights reserved.
|
|
| 35. |
|
|
| 36. |
- Wang, S. Y., et al.
(author)
-
High-spin level scheme of Cs-126
- 2004
-
In: Gaoneng wuli yu he wuli. - 0254-3052. ; 28:5, s. 491-494
-
Journal article (peer-reviewed)abstract
- High-spin states of Cs-126 have been populated via the Cd-116(N-14, 4n) Cs-126 reaction. The experiment was performed at Niels Bohr Institute in Denmark in 1991. After careful data analysis, most of the previously-known bands have been pushed up to much higher spins and 3 new rotational sequences have been identified. Spin, parity and configuration assignments are tentatively proposed for all of the observed bands.
|
|
| 37. |
- Herskind, B., et al.
(author)
-
Light charged particles as gateway to hyperdeformation
- 2007
-
In: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 38:4, s. 1421-1430
-
Journal article (peer-reviewed)abstract
- The Euroball-IV gamma-detector array, equipped with the ancillary charged particle detector array DIAMANT was used to study the residues of the fusion reaction Ni-64 + Ni-64 double right arrow Ba-128 at E-beam. = 255 and 261 MeV, in an attempt to reach the highest angular momentum and verify the existence of predicted hyperdeformed rotational bands. No discrete hyperdeformed bands were identified, but nevertheless a breakthrough was obtained through a systematic search for rotational ridge structures with very large moments of inertia J(2) >= 100 h(2) MeV((-1)), in agreement with theoretical predictions for hyperdeformed shapes. Evidence for hyperdeformation was obtained by charged particle + gamma-ray gating, selecting triple correlated ridge structures in the continuum of each of the nuclei, Te-118, Xe-124 and Cs-124,Cs-125. In 7 additional nuclei, rotational ridges were also identified with J(2) = 71-77h(2) MeV((-1)), which most probably correspond to superdeformed shape. The angular distributions of the emitted charged particles show an excess in forward direction over expectations from pure compound evaporation, which may indicate that in-complete fusion plays an important role in the population of very elongated shapes.
|
|
| 38. |
- Jensen, DR, et al.
(author)
-
Wobbling phonon excitations, coexisting with normal deformed structures in Lu-163
- 2002
-
In: Nuclear Physics, Section A. - 0375-9474. ; 703:1-2, s. 3-44
-
Journal article (peer-reviewed)abstract
- Wobbling is a rotational mode unique to a triaxial body. The Lu-Hf isotopes with N similar to 94 at high spin provide a possible region of nuclei with pronounced triaxiality. We have investigated Lu-163 through the fusion-evaporation reaction La-139(Si-29,5n)Lu-163 with a beam energy of 152 MeV. Three excited bands decaying into the known, presumably triaxial, superdeformed (TSD) band built on the i(13/2) proton orbital are observed. The electromagnetic properties of the connecting transitions from the two strongest populated excited TSD bands have been investigated. New particle-rotor calculations in which one i(13/2) quasiproton is coupled to the core of triaxial shape produce a variety of bands, whose properties can clearly be interpreted either as "wobbling" or "cranking" motion of the core. Evidence for the assignment of the excited TSD bands as one, and possibly even two wobbling phonon modes built on the yrast TSD band in Lu-163 is given. These triaxial bands coexist with bands built on quasiparticle excitations in the normal deformed (ND) minimum for which new data are also presented.
|
|
| 39. |
- Schnack-Petersen, H, et al.
(author)
-
Superdeformed triaxial bands in Lu-163,165
- 1995
-
In: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 594:2, s. 175-202
-
Journal article (peer-reviewed)abstract
- An experimental investigation of the nucleus 165Lu, using the reactions 138Ba(31P,4n) 165Lu and 150Sm(19F,4n) 165Lu at beam energies of E = 155 and 95 MeV, respectively, has been performed. Among other additions to the existing level scheme, a new band, with transition energies almost identical to a strongly deformed (β2 0.42) πi13/2[660 1/2+] band recently discovered in 163Lu has been established. A theoretical analysis of the structure of the two Lu isotopes, 165Lu and 163Lu is carried out by detailed calculations of total potential energy surfaces for specific configurations. By a diabatic treatment of crossings specific proton configurations as πi13/2[660 1/2+] are identified throughout the deformation space and as a function of spin. It is found as a general feature that well deformed local minima of considerable nonaxial symmetry coexist with a normal deformed global minimum. The depth of these local minima depend on configuration. The structure of the different global and local minima found in these surfaces are analysed and discussed in terms of occupation of available basis configurations and their orientation relative to the rotation axis. The strongly deformed minima are found to belong to a group of superdeformed triaxial structures, expected to appear at low energies for certain favourable combinations of proton and neutron numbers.
|
|
| 40. |
- Schonwasser, G, et al.
(author)
-
Lifetimes of triaxial superdeformed states in Lu-163 and Lu-164
- 2002
-
In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 13:3, s. 291-296
-
Journal article (peer-reviewed)abstract
- Lifetimes of states in the yrast superdeformed bands of Lu-163 and Lu-164 were determined in a Doppler-shift attenuation-method experiment. From fractional Doppler shifts and line shapes, average transition quadrupole moments, Q(t) = 8.2(-0.6)(+1.0) b and 7.1(-0.6)(+0.5) 1), were deduced for one of the bands in Lu-163 OX -0.6 and Lu-164, respectively. These values are much larger than the quadrupole moment of the normal-deformed yrast band in Yb-163, Q(t) = 4.9(-0.4)(+1.34) b, that was also determined in this experiment. Comparison to cranking calculations indicates that both superdeformed bands correspond to a local potential energy minimum with a pronounced triaxiality, gamma similar to 20degrees.
|
|
| 41. |
- Simpson, J., et al.
(author)
-
Discrete line γ-ray spectroscopy in the (50-60)ℏ spin domain of 161,162Er
- 2000
-
In: Physical Review C - Nuclear Physics. - 0556-2813. ; 62:2, s. 243211-243218
-
Journal article (peer-reviewed)abstract
- Very high spin states (I=50-60ℏ) have been observed in the transitional nuclei 161Er and 162Er using the Euroball γ-ray spectrometer. In 161Er, three bands are observed well above spin 50ℏ. In the positive parity, positive signature (+, + 1/2) band a discontinuity in the regular rotational behavior occurs at 109/2+ and a splitting into two branches occurs at 97/2- in the negative parity, positive signature (-, + 1/2) band. The ( -, - 1/2) band continues in a regular fashion to 115/2-, tentatively (119/2-). In 162Er the positive parity, even spin (+, 0) yrast band is observed to continue smoothly up to 58+ (60+) and the negative parity, even spin (-,0) and odd spin (-,1) bands are extended from 30- to 34- and from 31- to 47- (49-), respectively. The high spin experimental spectra are compared with both a simple model involving the occupation of specific single neutron states in the absence of neutron pair correlations and with more detailed cranked Nilsson-Strutinsky calculations in which both proton and neutron pairing correlations are neglected. The very high spin domain is found to comprise a series of unpaired rotational bands. Unpaired band crossings between bands with different neutron and proton configurations are identified in 161Er. There is no evidence for aligned oblate or terminating states being close to the yrast line in 161,162Er up to spin ≈60ℏ in contrast to the lighter Er isotopes.
|
|
| 42. |
- Singh, A. K., et al.
(author)
-
Absence of paired crossing in the positive parity bands of Cs 124
- 2018
-
In: Physical Review C. - 2469-9985. ; 97:2
-
Journal article (peer-reviewed)abstract
- High-spin states in Cs124 were populated in the Ni64(Ni64,p3n) reaction and the Gammasphere detector array was used to measure γ-ray coincidences. Both positive- and negative-parity bands, including bands with chiral configurations, have been extended to higher spin, where a shape change has been observed. The configurations of the bands before and after the alignment are discussed within the framework of the cranked Nilsson-Strutinsky model. The calculations suggest that the nucleus undergoes a shape transition from triaxial to prolate around spin I≃22 of the positive-parity states. The alignment gain of 8â.,, observed in the positive-parity bands, is due to partial alignment of several valence nucleons. This indicates the absence of band crossing due to paired nucleons in the bands.
|
|
| 43. |
- Wang, S. Y., et al.
(author)
-
Band structures in I-123
- 2006
-
In: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 32:3, s. 283-294
-
Journal article (peer-reviewed)abstract
- Excited states of I-123 were populated via the Cd-116(N-14, alpha 3n) reaction at 65 MeV. The resultant gamma-rays were detected using standard gamma-ray spectroscopic techniques with the NORDBALL detector array. Two previously known positive-parity Delta I = 2 sequences have been extended up to 31/2(+) and 41/2(+). In addition, a number of Delta I = 1 transitions linking the two Delta I = 2 sequences have been observed. It is suggested that both Delta I = 2 sequences are based on a common configuration. This Delta I = 1 band is proposed to be built predominantly on the 97/2[404]7/2(+) oblate configuration, based on the energylevel spectra, B(MI)/B(E2) ratios and the theoretical predictions from the particle-rotor model. The previously identified Delta I = 1 rotational band built on the prolate g(9/2)[404]9/2(+) orbital has also been extended to higher spins. Another previously identified but weakly populated Delta I = 1 band is confirmed and is proposed to be built on the d(5/2)[413]5/2' configuration with the ground state of I-123 as the bandhead.
|
|
| 44. |
- Wang, S. Y., et al.
(author)
-
Structure of the pi g(7/2) 404 7/2(+) band in odd proton nucleus I-123
- 2004
-
In: Chinese Physics Letters. - 0256-307X .- 1741-3540. ; 21:6, s. 1024-1026
-
Journal article (peer-reviewed)abstract
- High spin states of the odd proton nucleus I-123 have been populated in the reaction Cd-116(N-14, 5n2p) at a beam energy of 65 MeV. Two previously known positive-parity DeltaI = 2 sequences have been extended up to 31/2(+) and 41/2(+). In addition, a number of DeltaI = 1 transitions linking the two DeltaI = 2 sequences have been observed. It is suggested that both the DeltaI = 2 sequences are built upon the oblate pi(g) (7/2)[404]7/2(+) Nilsson configuration.
|
|
| 45. |
- Atac, A, et al.
(author)
-
Single-step link of the superdeformed band in Eu-143
- 1996
-
In: ZEITSCHRIFT FUR PHYSIK A-HADRONS AND NUCLEI. - : SPRINGER VERLAG. - 0939-7922. ; 355:4, s. 343-344
-
Journal article (other academic/artistic)abstract
- A discrete gamma-ray transition with an energy of 3360.6 keV deexciting the second lowest SD state in Eu-143 has been discovered. It carries 3.2 % of the full intensity of the band and feeds into a nearly spherical state which is above the I = 35/2((+)),
|
|
| 46. |
- Axelsson, A, et al.
(author)
-
Single-step link from yrast SD band in Eu-143
- 1997
-
In: PROGRESS IN PARTICLE AND NUCLEAR PHYSICS. - : PERGAMON PRESS LTD. - 0146-6410. ; 38, s. 51-52
-
Journal article (other academic/artistic)abstract
- A discrete gamma-ray transition from the yrast SD band to the region of near-yrast discrete normal-deformed states has been identified in Eu-143. It has an energy of 3360.6 keV and an intensity corresponding to 3.2% of the full intensity of the SD band an
|
|
| 47. |
- Bundgaard, E., et al.
(author)
-
Matrix Organization and Merit Factor Evaluation as a Method to Address the Challenge of Finding a Polymer Material for Roll Coated Polymer Solar Cells
- 2015
-
In: Advanced Energy Materials. - : Wiley. - 1614-6840 .- 1614-6832. ; 5:10, s. Art. no. 1402186-
-
Journal article (peer-reviewed)abstract
- The results presented demonstrate how the screening of 104 light-absorbing low band gap polymers for suitability in roll coated polymer solar cells can be accomplished through rational synthesis according to a matrix where 8 donor and 13 acceptor units are organized in rows and columns. Synthesis of all the polymers corresponding to all combinations of donor and acceptor units is followed by characterization of all the materials with respect to molecular weight, electrochemical energy levels, band gaps, photochemical stability, carrier mobility, and photovoltaic parameters. The photovoltaic evaluation is carried out with specific reference to scalable manufacture, which includes large area (1 cm(2)), stable inverted device architecture, an indium-tin-oxide-free fully printed flexible front electrode with ZnO/PEDOT:PSS (poly(3,4-ethylenedioxythiophene):polystyrene sulfonate), and a printed silver comb back electrode structure. The matrix organization enables fast identification of active layer materials according to a weighted merit factor that includes more than simply the power conversion efficiency and is used as a method to identify the lead candidates. Based on several characteristics included in the merit factor, it is found that 13 out of the 104 synthesized polymers outperformed poly(3-hexylthiophene) under the chosen processing conditions and thus can be suitable for further development.
|
|
| 48. |
|
|
| 49. |
- Hamamoto-Kuroda, Ikuko, et al.
(author)
-
Quantized wobbling excitations with alignments
- 2003
-
In: Physical Review C (Nuclear Physics). - 0556-2813. ; 67:1: 014319
-
Journal article (peer-reviewed)abstract
- The wobbling excitations in the presence of an appreciable amount of alignment are expected to appear more easily at lower angular momenta of the yrast spectra, compared with those in the textbook example. The large B(E2;I-->I-1) value for Delta(n) over cap =1 transitions where (n) over cap expresses the number of wobbling phonons is shown to be a strongly increasing function of the triaxiality parameter gamma, especially for gammagreater than or similar to+20degrees, while it is relatively independent of moments of inertia. On the other hand, the relation of the wobbling phonon energy to the total angular momentum may be used to extract quantitative information on nuclear moments of inertia. It is concluded that the gamma value of the triaxial, strongly deformed bands in Lu-163 is about equal to +20degrees and may be slightly increasing as a function of I.
|
|
| 50. |
|
|
