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13 results on '"RICH NUCLEI"'

1. First beta-decay spectroscopy of In-135 and new beta-decay branches of In-134

Author

Piersa-Silkowska, M, Korgul, A, Benito, J, Fraile, LM, Adamska, E, Andreyev, AN, Alvarez-Rodriguez, R, Barzakh, AE, Benzoni, G, Berry, T, Borge, MJG, Carmona, M, Chrysalidis, K, Correia, JG, Costache, C, Cubiss, JG, Goodacre, T Day, De Witte, H, Fedorov, D, Fedosseev, VN, Fernandez-Martinez, G, Fijalkowska, A, Fynbo, H, Galaviz, D, Galve, P, Garcia-Diez, M, Greenlees, PT, Grzywacz, R, Harkness-Brennan, LJ, Henrich, C, Huyse, M, Ibanez, P, Illana, A, Janas, Z, Johnston, K, Jolie, J, Judson, DS, Karanyonchev, V, Kicinska-Habior, M, Konki, J, Koszuk, L, Kurcewicz, J, Lazarus, I, Lica, R, Lopez-Montes, A, Mach, H, Madurga, M, Marroquin, I, Marsh, B, Martinez, MC, Mazzocchi, C, Miernik, K, Mihai, C, Marginean, N, Marginean, R, Negret, A, Nacher, E, Ojala, J, Olaizola, B, Page, RD, Pakarinen, J, Pascu, S, Paulauskas, S, Perea, A, Pucknell, V, Rahkila, P, Raison, C, Rapisarda, E, Rezynkina, K, Rotaru, F, Rothe, S, Rykaczewski, KP, Regis, J-M, Schomacker, K, Silkowski, M, Simpson, G, Sotty, C, Stan, L, Stanoiu, M, Stryjczyk, M, Sanchez-Parcerisa, D, Sanchez-Tembleque, V, Tengblad, O, Turturica, A, Udias, JM, Van Duppen, P, Vedia, V, Villa, A, Vinals, S, Wadsworth, R, Walters, WB, Warr, N, and Wilkins, SG

Subjects
ISOMER, Science & Technology, NEUTRON EMISSION PROBABILITIES, Physics, MODEL, Physics, Nuclear, NUCLEAR-DATA SHEETS, STATES, Physical Sciences, ISOTOPES, PICOSECOND LIFETIME MEASUREMENTS, RICH NUCLEI, HALF-LIVES, SN-132
Abstract

ispartof: PHYSICAL REVIEW C vol:104 issue:4 status: published

Published
2021

2. First beta-decay spectroscopy of In-135 and new beta-decay branches of In-134

Author

Benito García, Jaime, Fraile Prieto, Luis Mario, Carmona, M., Galve Lahoz, Pablo, García Díez, P., Ibañez, P., López Montes, A., Martínez, M. C., Sánchez Parcerisa, Daniel, Sánchez Tembleque, Víctor, Udías Moinelo, José Manuel, Vedia Fernández, María Victoria, Villa, A., otros, ..., Benito García, Jaime, Fraile Prieto, Luis Mario, Carmona, M., Galve Lahoz, Pablo, García Díez, P., Ibañez, P., López Montes, A., Martínez, M. C., Sánchez Parcerisa, Daniel, Sánchez Tembleque, Víctor, Udías Moinelo, José Manuel, Vedia Fernández, María Victoria, Villa, A., and otros, ...

Abstract

Artículo firmado por 93 autores. M.P.-S. acknowledges the funding support from the Polish National Science Center under Grants No. 2019/33/N/ST2/03023 and No. 2020/36/T/ST2/00547 (Doctoral scholarship ETIUDA). J.B. acknowledges support from the Universidad Complutense de Madrid under the Predoctoral Grant No. CT27/16CT28/16. This work was partially funded by the Polish National Science Center under Grants No. 2020/39/B/ST2/02346, No. 2015/18/E/ST2/00217, and No. 2015/18/M/ST2/00523, by the Spanish government via Projects No. FPA2017-87568-P, No. RTI2018-09886 8-B-I00, No. PID2019-104390GB-I00, and No. PID2019-104714GB-C21, by the U.K. Science and Technology Facilities Council (STFC), the German BMBF under Contract No. 05P18PKCIA, by the Portuguese FCT under the Projects No. CERN/FIS-PAR/0005/2017, and No. CERN/FIS-TEC/0003/2019, and by the Romanian IFA Grant CERN/ISOLDE. The research leading to these results has received funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 654002. M.Str. acknowledges the funding from the European Union's Horizon 2020 research and innovation program under Grant Agreement No. 771036 (ERC CoG MAIDEN). J.P. acknowledges support from the Academy of Finland (Finland) with Grant No. 307685. Work at the University of York was supported under STFC Grants No. ST/L005727/1 and No. ST/P003885/1., The beta decay of the neutron-rich In-134 and In-135 was investigated experimentally in order to provide new insights into the nuclear structure of the tin isotopes with magic proton number Z = 50 above the N = 82 shell. The beta-delayed gamma-ray spectroscopy measurement was performed at the ISOLDE facility at CERN, where indium isotopes were selectively laser-ionized and on-line mass separated. Three beta-decay branches of In-134 were established, two of which were observed for the first time. Population of neutron-unbound states decaying via. rays was identified in the two daughter nuclei of In-134, Sn-134 and Sn-133, at excitation energies exceeding the neutron separation energy by 1 MeV. The beta-delayed one- and two-neutron emission branching ratios of In-134 were determined and compared with theoretical calculations. The beta-delayed one-neutron decay was observed to be dominant beta-decay branch of In-134 even though the Gamow-Teller resonance is located substantially above the two-neutron separation energy of Sn-134. Transitions following the beta decay of In-135 are reported for the first time, including. rays tentatively attributed to Sn-135. In total, six new levels were identified in Sn-134 on the basis of the beta.. coincidences observed in the In-134 and In-135 beta decays. A transition that might be a candidate for deexciting the missing neutron single-particle 13/2(+) state in Sn-133 was observed in both beta decays and its assignment is discussed. Experimental level schemes of Sn-134 and Sn-135 are compared with shell-model predictions. Using the fast timing technique, half-lives of the 2(+), 4(+), and 6(+) levels in Sn-134 were determined. From the lifetime of the 4(+) state measured for the first time, an unexpectedly large B(E2; 4(+)-> 2(+)) transition strength was deduced, which is not reproduced by the shell-model calculations., Unión Europea. Horizonte 2020, Ministerio de Economía y Competitividad (MINECO), Polish National Science Center, Universidad Complutense de Madrid, U.K. Science and Technology Facilities Council (STFC) UK Research & Innovation (UKRI) Science & Technology Facilities Council (STFC), German BMBF Federal Ministry of Education & Research (BMBF), Portuguese FCT Portuguese Foundation for Science and Technology, Romanian IFA Grant CERN/ISOLDE, Comisión Europea, Academy of Finland, STFC UK Research & Innovation (UKRI) Science & Technology Facilities Council (STFC), Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub

Published
2021

3. Effective proton-neutron interaction near the drip line from unbound states in F-25,F-26

Author

Kalantar-Nayestanaki, N., Najafi, M., Rigollet, C., and Research unit Nuclear & Hadron Physics

Subjects
RICH NUCLEI, Nuclear Experiment, DETECTOR
Abstract

Background: Odd-odd nuclei, around doubly closed shells, have been extensively used to study proton-neutron interactions. However, the evolution of these interactions as a function of the binding energy, ultimately when nuclei become unbound, is poorly known. The F-26 nucleus, composed of a deeply bound pi 0d(5/2) proton and an unbound v0d(3/2) neutron on top of an O-24 core, is particularly adapted for this purpose. The coupling of this proton and neutron results in a J(pi) = 1(1)(+) - 4(1)(+) multiplet, whose energies must be determined to study the influence of the proximity of the continuum on the corresponding proton-neutron interaction. The J(pi) = 1(1)(+), 2(1)(+), 4(1)(+) bound states have been determined, and only a clear identification of the J(pi) = 3(1)(+) is missing. Purpose: We wish to complete the study of the J(pi) = 1(1)(+) - 4(1)(+) multiplet in F-26, by studying the energy and width of the J(pi) = 3(1)(+) unbound state. The method was first validated by the study of unbound states in F-25, for which resonances were already observed in a previous experiment. Method: Radioactive beams of Ne-26 and Ne-27, produced at about 440AMeV by the fragment separator at the GSI facility were used to populate unbound states in F-25 and F-26 via one-proton knockout reactions on a CH2 target, located at the object focal point of the (RB)-B-3/LAND setup. The detection of emitted. rays and neutrons, added to the reconstruction of the momentum vector of the A - 1 nuclei, allowed the determination of the energy of three unbound states in F-25 and two in F-26. Results: Based on its width and decay properties, the first unbound state in F-25, at the relative energy of 49(9) keV, is proposed to be a J(pi) = 1/ 2(-) arising from a p1/2 proton- hole state. In F-26, the first resonance at 323(33) keV is proposed to be the J(pi) = 3(1)(+) member of the J(pi) = 1(1)(+) - 4(1)(+) multiplet. Energies of observed states in F-25,F-26 have been compared to calculations using the independent-particle shell model, a phenomenological shell model, and the ab initio valence-space in-medium similarity renormalization group method. Conclusions: The deduced effective proton- neutron interaction is weakened by about 30-40% in comparison to the models, pointing to the need for implementing the role of the continuum in theoretical descriptions or to a wrong determination of the atomic mass of F-26.

Published
2017

4. Effective proton-neutron interaction near the drip line from unbound states in F-25,F-26

Subjects
RICH NUCLEI, DETECTOR
Abstract

Background: Odd-odd nuclei, around doubly closed shells, have been extensively used to study proton-neutron interactions. However, the evolution of these interactions as a function of the binding energy, ultimately when nuclei become unbound, is poorly known. The F-26 nucleus, composed of a deeply bound pi 0d(5/2) proton and an unbound v0d(3/2) neutron on top of an O-24 core, is particularly adapted for this purpose. The coupling of this proton and neutron results in a J(pi) = 1(1)(+) - 4(1)(+) multiplet, whose energies must be determined to study the influence of the proximity of the continuum on the corresponding proton-neutron interaction. The J(pi) = 1(1)(+), 2(1)(+), 4(1)(+) bound states have been determined, and only a clear identification of the J(pi) = 3(1)(+) is missing.Purpose: We wish to complete the study of the J(pi) = 1(1)(+) - 4(1)(+) multiplet in F-26, by studying the energy and width of the J(pi) = 3(1)(+) unbound state. The method was first validated by the study of unbound states in F-25, for which resonances were already observed in a previous experiment.Method: Radioactive beams of Ne-26 and Ne-27, produced at about 440AMeV by the fragment separator at the GSI facility were used to populate unbound states in F-25 and F-26 via one-proton knockout reactions on a CH2 target, located at the object focal point of the (RB)-B-3/LAND setup. The detection of emitted. rays and neutrons, added to the reconstruction of the momentum vector of the A - 1 nuclei, allowed the determination of the energy of three unbound states in F-25 and two in F-26.Results: Based on its width and decay properties, the first unbound state in F-25, at the relative energy of 49(9) keV, is proposed to be a J(pi) = 1/ 2(-) arising from a p1/2 proton- hole state. In F-26, the first resonance at 323(33) keV is proposed to be the J(pi) = 3(1)(+) member of the J(pi) = 1(1)(+) - 4(1)(+) multiplet. Energies of observed states in F-25,F-26 have been compared to calculations using the independent-particle shell model, a phenomenological shell model, and the ab initio valence-space in-medium similarity renormalization group method.Conclusions: The deduced effective proton- neutron interaction is weakened by about 30-40% in comparison to the models, pointing to the need for implementing the role of the continuum in theoretical descriptions or to a wrong determination of the atomic mass of F-26.

Published
2017

5. Beyond the neutron drip line

Subjects
Nuclear Theory, RICH NUCLEI, PARTICLE STABILITY, Nuclear Experiment, DETECTOR, RELATIVISTIC HEAVY-IONS
Abstract

The very neutron-rich oxygen isotopes O-25 and O-26 are investigated experimentally and theoretically. The unbound states are populated in an experiment performed at the R3B-LAND setup at GSI via proton-knockout reactions from F-26 and F-27 at relativistic energies around 442 and 414 MeV/nucleon, respectively. From the kinematically complete measurement of the decay into O-24 plus one or two neutrons, the O-25 ground-state energy and width are determined, and upper limits for the O-26 ground-state energy and lifetime are extracted. In addition, the results provide indications for an excited state in O-26 at around 4 MeV. The experimental findings are compared to theoretical shell-model calculations based on chiral two- and three-nucleon (3N) forces, including for the first time residual 3N forces, which are shown to be amplified as valence neutrons are added.

Published
2013

6. Beyond the neutron drip line: The unbound oxygen isotopes O-25 and O-26

Author

Caesar, C., Simonis, J., Adachi, T., Aksyutina, Y., Alcantara, J., Altstadt, S., Alvarez-Pol, H., Ashwood, N., Aumann, T., Avdeichikov, V., Barr, M., Beceiro, S., Bemmerer, D., Benlliure, J., Bertulani, C. A., Boretzky, K., Borge, M. J. G., Burgunder, G., Caamano, M., Casarejos, E., Catford, W., Cederkaell, J., Chakraborty, S., Chartier, M., Chulkov, L., Cortina-Gil, D., Pramanik, U. Datta, Fernandez, P. Diaz, Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fraile, L. M., Freer, M., Freudenberger, M., Fynbo, H. O. U., Galaviz, D., Geissel, H., Gernhaeuser, R., Golubev, P., Diaz, D. Gonzalez, Hagdahl, J., Heftrich, T., Heil, M., Kalantar-Nayestanaki, N., Rigollet, C., Streicher, B., Van de Walle, J., and KVI - Center for Advanced Radiation Technology

Subjects
Nuclear Theory, RICH NUCLEI, PARTICLE STABILITY, Nuclear Experiment, DETECTOR, RELATIVISTIC HEAVY-IONS
Abstract

The very neutron-rich oxygen isotopes O-25 and O-26 are investigated experimentally and theoretically. The unbound states are populated in an experiment performed at the R3B-LAND setup at GSI via proton-knockout reactions from F-26 and F-27 at relativistic energies around 442 and 414 MeV/nucleon, respectively. From the kinematically complete measurement of the decay into O-24 plus one or two neutrons, the O-25 ground-state energy and width are determined, and upper limits for the O-26 ground-state energy and lifetime are extracted. In addition, the results provide indications for an excited state in O-26 at around 4 MeV. The experimental findings are compared to theoretical shell-model calculations based on chiral two- and three-nucleon (3N) forces, including for the first time residual 3N forces, which are shown to be amplified as valence neutrons are added.

Published
2013

7. Precision measurement of Li-11 moments: Influence of halo neutrons on the Li-9 core

Author

Neugart, R, Balabanski, DL, Blaum, K, Borremans, D, Himpe, P, Kowalska, M, Lievens, Peter, Mallion, S, Neyens, Gerda, Vermeulen, N, and Yordanov, DT

Subjects
halo nuclei, nuclear moments, be-11, magnetic-moment, shell-model, rich nuclei, moments, spin
Abstract

The electric quadrupole moment and the magnetic moment of the Li-11 halo nucleus have been measured with more than an order of magnitude higher precision than before, vertical bar Q vertical bar = 33.3(5) mb and mu = +3.6712(3)mu(N), revealing a 8.8(1.5)% increase of the quadrupole moment relative to that of Li-9. This result is compared to various models that aim at describing the halo properties. In the shell model an increased quadrupole moment points to a significant occupation of the 1d orbits, whereas in a simple halo picture this can be explained by relating the quadrupole moments of the proton distribution to the charge radii. Advanced models so far fail to reproduce simultaneously the trends observed in the radii and quadrupole moments of the lithium isotopes. 4 pages, 4 figures, 1 table ispartof: Physical Review Letters vol:101 issue:13 ispartof: location:United States status: published

Published
2008

8. A data analysis method for isochronous mass spectrometry using two time-of-flight detectors at CSRe

Author

Yan Xinliang, Meng Wang, Xiao-Lin Tu, Wei Zhang, C. Y. Fu, Wen Ge, Yuan-Ming Xing, Xiang-Cheng Chen, R.J. Chen, Qi Zeng, Zhang Yu-Hu, D.W. Liu, Yuri A. Litvinov, Yuan You-Jin, Xu Hu-Shan, Ge Zhuang, W. Huang, Xu Xing, Sergey Litvinov, Hu Xue-Jing, Shuai Peng, Zhou Xiao-Hong, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM SNO), and Université Paris-Saclay-Univ. Paris-Sud-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Accelerator Physics (physics.acc-ph), Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, cooler storage ring, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], EXPERIMENTAL STORAGE-RING, isochronous mass spectrometry, GSI, Nuclear physics, symbols.namesake, Nuclide, Nuclear Experiment (nucl-ex), Nuclear Experiment, Instrumentation, Analysis method, [PHYS]Physics [physics], Physics, Detector, Mode (statistics), Astronomy and Astrophysics, Instrumentation and Detectors (physics.ins-det), simulation, LANZHOU, exotic nuclei, LIVED EXOTIC NUCLEI, Time of flight, Lorentz factor, Isochronous mass spectrometry, symbols, Physics - Accelerator Physics, two TOF detectors, RICH NUCLEI, Storage ring, FRS-ESR FACILITY
Abstract

The concept of isochronous mass spectrometry (IMS) applying two time-of-flight (TOF) detectors originated many years ago at GSI. However, the corresponding method for data analysis has never been discussed in detail. Recently, two TOF detectors have been installed at CSRe and the new working mode of the ring is under test. In this paper, a data analysis method for this mode is introduced and tested with a series of simulations. The results show that the new IMS method can significantly improve mass resolving power via the additional velocity information of stored ions. This improvement is especially important for nuclides with Lorentz factor $\gamma$-value far away from the transition point $\gamma _t$ of the storage ring CSRe., Comment: published in Chinese Physics C Vol. 39, No. 10 (2015) 106201

Published
2015
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9. Evidence for a spin-aligned neutron-proton paired phase from the level structure of 92Pd

Author

Cederwall, Bo, Ghazi Moradi, Farnaz, Bäck, Torbjörn, Johnson, Arne, Blomqvist, Jan-Erik, Clément, E., de France, G., Wadsworth, R., Andgren, Karin, Lagergren, Karin, Dijon, A., Jaworski, G., Liotta, Roberto, Qi, Chong, Nyakó, B. M., Nyberg, J., Palacz, M., Al-Azri, H., Algora, A., de Angelis, G., Atac Nyberg, Ayse, Bhattacharyya, S., Brock, T., Brown, J. R., Davies, P., Di Nitto, A., Dombrádi, Zs., Gadea, A., Gál, J., Hadinia, Baharak, Johnston-Theasby, F., Joshi, P., Juhász, K., Julin, R., Jungclaus, A., Kalinka, G., Kara, S. O., Khaplanov, Anton, Kownacki, J., La Rana, G., Lenzi, S. M., Molnár, J., Moro, R., Napoli, D. R., Nara Singh, B. S., Persson, Andreas, Recchia, F., Sandzelius, Mikael, Scheurer, J. -N, Sletten, G., Sohler, D., Söderström, P. -A, Taylor, M. J., Timár, J., Valiente-Dobón, J. J., Vardaci, E., Williams, S., Cederwall, Bo, Ghazi Moradi, Farnaz, Bäck, Torbjörn, Johnson, Arne, Blomqvist, Jan-Erik, Clément, E., de France, G., Wadsworth, R., Andgren, Karin, Lagergren, Karin, Dijon, A., Jaworski, G., Liotta, Roberto, Qi, Chong, Nyakó, B. M., Nyberg, J., Palacz, M., Al-Azri, H., Algora, A., de Angelis, G., Atac Nyberg, Ayse, Bhattacharyya, S., Brock, T., Brown, J. R., Davies, P., Di Nitto, A., Dombrádi, Zs., Gadea, A., Gál, J., Hadinia, Baharak, Johnston-Theasby, F., Joshi, P., Juhász, K., Julin, R., Jungclaus, A., Kalinka, G., Kara, S. O., Khaplanov, Anton, Kownacki, J., La Rana, G., Lenzi, S. M., Molnár, J., Moro, R., Napoli, D. R., Nara Singh, B. S., Persson, Andreas, Recchia, F., Sandzelius, Mikael, Scheurer, J. -N, Sletten, G., Sohler, D., Söderström, P. -A, Taylor, M. J., Timár, J., Valiente-Dobón, J. J., Vardaci, E., and Williams, S.

Abstract

Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work(1) that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing(2-6), in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus Pd-92. Gamma rays emitted following the Ni-58(Ar-36,2n)Pd-92 fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution c-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction(2-6). We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling(7,8)) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis., QC 20110501

Published
2011
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10. Contrasting behavior in the rotational structure of the T-z=1/2 nuclei Kr-73 and Rb-75 : A possible fingerprint of T=0 neutron-proton pairing correlations

Author

Wyss, Ramon, Davies, Paul John, Satula, Wojtek, Wadsworth, Robert, Wyss, Ramon, Davies, Paul John, Satula, Wojtek, and Wadsworth, Robert

Abstract

Three different rotational bands have been observed to high spin in Rb-75 using Gammasphere. The structures are similar, but not identical to those found in the neighboring T-z=1/2 nucleus Kr-73. Conventional total Routhian surface (TRS) calculations with T=1 pairing are able to reproduce the rotational bands in Rb-75 with extreme accuracy, but they completely fail in reproducing the spectra and decay pattern of the negative parity bands in Kr-73. Simple qualitative arguments are put forward to show that the decay pattern observed in the negative parity bands in Kr-73 can be accounted for by means of T=0 pair correlations. To further corroborate this scenario, deformation, and pairing self-consistent TRS calculations, including schematic T=1 and T=0 pairing, are performed for the first time indicating the onset of dynamical T=0 pair-correlations at high angular momenta., QC 20100525

Published
2007
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11. Cranking in isospace - Applications to neutron-proton pairing and the nuclear symmetry energy

Author

Satula, Wojtek, Wyss, Ramon, Rafalski, M., Satula, Wojtek, Wyss, Ramon, and Rafalski, M.

Abstract

Isoscalar pairing interaction and nuclear symmetry energy are investigated by means of the iso-cranking technique. Iso-cranking represents the lowest order approximation to isospin projection after variation. Due to its internal simplicity, it offers a very intuitive understanding of the structure of the nuclear symmetry energy as well as the response of the isoscalar and isovector pairing versus isospin., QC 20100525 QC 20111017

Published
2005
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12. Cranking in isospace

Author

Glowacz, S., Satula, Wojtek, Wyss, Ramon, Glowacz, S., Satula, Wojtek, and Wyss, Ramon

Abstract

The response of isovector and isoscalar pair fields to generalized rotation in isospace is studied. Analytical expressions for constant gap solutions for different limiting cases of the model are derived. In particular, the connections between gauge angles among pairing gaps and the position of the iso-cranking axis are investigated in N = Z nuclei. The two domains of collective and noncollective rotation in space are generalized to isospace. The amplitudes for pair-transfer of T = 0 and T = 1 pairs are calculated. It is shown that the structure of the T = 0 state in odd-odd nuclei prevents any enhancement of pair transfer also in the presence of strong isoscalar pairing correlations. The energy differences of the T = 0 and T = 1 excitations in odd-odd nuclei are qualitatively reproduced by Total-Routhian-Surface calculations., QC 20100525

Published
2004
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13. A number projected model with generalized pairing interaction

Author

Satula, W., Wyss, Ramon, Satula, W., and Wyss, Ramon

Abstract

A mean-held model with a generalized pairing interaction that accounts for neutron-proton pairing is presented. Both the BCS as well as number-projected solutions of the model are presented. For the latter case the Lipkin-Nogami projection technique was extended to encompass the case of nonseparable proton-neutron systems. The influence of the projection on various pairing phases is discussed. In particular, it is shown that number-projection allows For mixing of different pairing phases but, simultanously, acts destructively on the proton-neutron correlations, The basic implications of proton-neutron pairing correlations on nuclear masses are discussed. It is shown that these correlations may provide a natural microscopic explanation of the Wigner energy lacking in mean-field models. A possible phase transition from isovector to isoscalar pairing condensate at high angular momenta is also discussed. In particular predictions for the dynamical moments of inertia for the superdeformed band in Ru-88 are given., QC 20100525

Published
2000
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