Lund University Publications
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Lund University Lund University Publications2000-01-01T00:00+00:001dailyElectromagnetic properties of low-lying states in neutron-deficient Hg isotopes : Coulomb excitation of <sup>182</sup>Hg, <sup>184</sup>Hg, <sup>186</sup>Hg and <sup>188</sup>Hg
https://lup.lub.lu.se/search/publication/cc141899-5b77-48c8-8d17-c25a91823ed2
Wrzosek-Lipska, K.Rezynkina, K.Bree, N.Zielińska, M.Gaffney, L. P.Petts, A.Andreyev, A.Bastin, B.Bender, M.Blazhev, A.Bruyneel, B.Butler, P. A.Carpenter, M. P.Cederkäll, J.Clément, E.Cocolios, T. E.Deacon, A. N.Diriken, J.Ekström, A.Fitzpatrick, C.Fraile, L. M.Fransen, ChFreeman, S. J.García-Ramos, J. E.Geibel, K.Gernhäuser, R.Grahn, T.Guttormsen, M.Hadinia, B.Hadyńska-Klȩk, K.Hass, M.Heenen, P. H.Herzberg, R. D.Hess, H.Heyde, K.Huyse, M.Ivanov, O.Jenkins, D. G.Julin, R.Kesteloot, N.Kröll, ThKrücken, R.Larsen, A. C.Lutter, R.Marley, P.Napiorkowski, P. J.Orlandi, R.Page, R. D.Pakarinen, J.Patronis, N.Peura, P. J.Piselli, E.Próchniak, L.Rahkila, P.Rapisarda, E.Reiter, P.Robinson, A. P.Scheck, M.Siem, S.Singh Chakkal, K.Smith, J. F.Srebrny, J.Stefanescu, I.Tveten, G. M.Van Duppen, P.Van de Walle, J.Voulot, D.Warr, N.Wiens, A.Wood, J. L.2019-08-01The neutron-deficient mercury isotopes serve as a classical example of shape coexistence, whereby at low energy near-degenerate nuclear states characterized by different shapes appear. The electromagnetic structure of even-mass 182-188 Hg isotopes was studied using safe-energy Coulomb excitation of neutron-deficient mercury beams delivered by the REX-ISOLDE facility at CERN. The population of 01,2+, 21,2+ and 41+ states was observed in all nuclei under study. Reduced E2 matrix elements coupling populated yrast and non-yrast states were extracted, including their relative signs. These are a sensitive probe of shape coexistence and may be used to validate nuclear models. The experimental results are discussed in terms of mixing of two different configurations and are compared with three different model calculations: the Beyond Mean Field model, the Interacting Boson Model with configuration mixing and the General Bohr Hamiltonian. Partial agreement with experiment was observed, hinting to missing ingredients in the theoretical descriptions.http://lup.lub.lu.se/record/cc141899-5b77-48c8-8d17-c25a91823ed2http://dx.doi.org/10.1140/epja/i2019-12815-2scopus:85071016875engEuropean Physical Journal A; 55(8), no 130 (2019)ISSN: 1434-6001Subatomic PhysicsElectromagnetic properties of low-lying states in neutron-deficient Hg isotopes : Coulomb excitation of 182Hg, 184Hg, 186Hg and 188Hgcontributiontojournal/articleinfo:eu-repo/semantics/articletextStrong Neutron Pairing in core+4n Nuclei
https://lup.lub.lu.se/search/publication/793ff7c0-850b-4298-8099-46c01b582f5e
Revel, A.Marqués, F. M.Sorlin, O.Aumann, T.Caesar, C.Holl, M.Panin, V.Vandebrouck, M.Wamers, F.Alvarez-Pol, H.Atar, L.Avdeichikov, V.Beceiro-Novo, S.Bemmerer, D.Benlliure, J.Bertulani, C. A.Boillos, J. M.Boretzky, K.Borge, M. J.G.Caamaño, M.Casarejos, E.Catford, W. N.Cederkäll, J.Chartier, M.Chulkov, L.Cortina-Gil, D.Cravo, E.Crespo, R.Datta Pramanik, U.Díaz Fernández, P.Dillmann, I.Elekes, Z.Enders, J.Ershova, O.Estradé, A.Farinon, F.Fraile, L. M.Freer, M.Galaviz, D.Geissel, H.Gernhäuser, R.Golubev, P.Göbel, K.Hagdahl, J.Heftrich, T.Heil, M.Heine, M.Heinz, A.Henriques, A.Knyazev, A.2018-04-12The emission of neutron pairs from the neutron-rich N=12 isotones C18 and O20 has been studied by high-energy nucleon knockout from N19 and O21 secondary beams, populating unbound states of the two isotones up to 15 MeV above their two-neutron emission thresholds. The analysis of triple fragment-n-n correlations shows that the decay N19(-1p)C18∗→C16+n+n is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a C14 core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay O21(-1n)O20∗→O18+n+n, attributed to its formation through the knockout of a deeply bound neutron that breaks the O16 core and reduces the number of pairs.http://lup.lub.lu.se/record/793ff7c0-850b-4298-8099-46c01b582f5ehttp://dx.doi.org/10.1103/PhysRevLett.120.152504pmid:29756867scopus:85045325864engPhysical Review Letters; 120(15), no 152504 (2018)ISSN: 0031-9007Subatomic PhysicsStrong Neutron Pairing in core+4n Nucleicontributiontojournal/articleinfo:eu-repo/semantics/articletextQuasifree (p,pN) scattering of light neutron-rich nuclei near N=14
https://lup.lub.lu.se/search/publication/fb06d318-5c3f-4566-b707-28ddd667c9b4
Díaz Fernández, P.Alvarez-Pol, H.Crespo, R.Cravo, E.Atar, L.Deltuva, A.Aumann, T.Avdeichikov, V.Beceiro-Novo, S.Bemmerer, D.Benlliure, J.Bertulani, C. A.Boillos, J. M.Boretzky, K.Borge, M. J.G.Caamaño, M.Cabanelas, P.Caesar, C.Casarejos, E.Catford, W.Cederkäll, J.Chartier, M.Chulkov, L. V.Cortina-Gil, D.Datta Pramanik, U.Dillmann, I.Elekes, Z.Enders, J.Ershova, O.Estradé, A.Farinon, F.Fernández-Domínguez, B.Fraile, L. M.Freer, M.Galaviz, D.Geissel, H.Gernhäuser, R.Golubev, P.Göbel, K.Hagdahl, J.Heftrich, T.Heil, M.Heine, M.Heinz, A.Henriques, A.Holl, M.Hufnagel, A.Ignatov, A.Johansson, H. T.Knyazev, A.2018-02-09Background: For many years, quasifree scattering reactions in direct kinematics have been extensively used to study the structure of stable nuclei, demonstrating the potential of this approach. The RB3 collaboration has performed a pilot experiment to study quasifree scattering reactions in inverse kinematics for a stable C12 beam. The results from that experiment constitute the first quasifree scattering results in inverse and complete kinematics. This technique has lately been extended to exotic beams to investigate the evolution of shell structure, which has attracted much interest due to changes in shell structure if the number of protons or neutrons is varied. Purpose: In this work we investigate for the first time the quasifree scattering reactions (p,pn) and (p,2p) simultaneously for the same projectile in inverse and complete kinematics for radioactive beams with the aim to study the evolution of single-particle properties from N=14 to N=15. Method: The structure of the projectiles O23, O22, and N21 has been studied simultaneously via (p,pn) and (p,2p) quasifree knockout reactions in complete inverse kinematics, allowing the investigation of proton and neutron structure at the same time. The experimental data were collected at the R3B-LAND setup at GSI at beam energies of around 400 MeV/u. Two key observables have been studied to shed light on the structure of those nuclei: the inclusive cross sections and the corresponding momentum distributions. Conclusions: The knockout reactions (p,pn) and (p,2p) with radioactive beams in inverse kinematics have provided important and complementary information for the study of shell evolution and structure. For the (p,pn) channels, indications of a change in the structure of these nuclei moving from N=14 to N=15 have been observed, i.e., from the 0d5/2 shell to the 1s1/2. This supports previous observations of a subshell closure at N=14 for neutron-rich oxygen isotopes and its weakening for the nitrogen isotopes.http://lup.lub.lu.se/record/fb06d318-5c3f-4566-b707-28ddd667c9b4http://dx.doi.org/10.1103/PhysRevC.97.024311scopus:85042128067engPhysical Review C; 97(2), no 024311 (2018)ISSN: 2469-9985Subatomic PhysicsQuasifree (p,pN) scattering of light neutron-rich nuclei near N=14contributiontojournal/articleinfo:eu-repo/semantics/articletextQuasifree (p, 2p) Reactions on Oxygen Isotopes : Observation of Isospin Independence of the Reduced Single-Particle Strength
https://lup.lub.lu.se/search/publication/613b71e4-25ef-4711-b80e-2359dca8b2ad
Atar, L.Paschalis, S.Barbieri, C.Bertulani, C. A.Díaz Fernández, P.Holl, M.Najafi, M. A.Panin, V.Alvarez-Pol, H.Aumann, T.Avdeichikov, V.Beceiro-Novo, S.Bemmerer, D.Benlliure, J.Boillos, J. M.Boretzky, K.Borge, M. J.G.Caamaño, M.Caesar, C.Casarejos, E.Catford, W.Cederkall, J.Chartier, M.Chulkov, L.Cortina-Gil, D.Cravo, E.Crespo, R.Dillmann, I.Elekes, Z.Enders, J.Ershova, O.Estrade, A.Farinon, F.Fraile, L. M.Freer, M.Galaviz Redondo, D.Geissel, H.Gernhäuser, R.Golubev, P.Göbel, K.Hagdahl, J.Heftrich, T.Heil, M.Heine, M.Heinz, A.Henriques, A.Hufnagel, A.Ignatov, A.Johansson, H. T.Knyazev, A.2018-01-29Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure of stable and exotic oxygen isotopes at the R3B/LAND setup with incident beam energies in the range of 300-450 MeV/u. The oxygen isotopic chain offers a large variation of separation energies that allows for a quantitative understanding of single-particle strength with changing isospin asymmetry. Quasifree knockout reactions provide a complementary approach to intermediate-energy one-nucleon removal reactions. Inclusive cross sections for quasifree knockout reactions of the type OA(p,2p)NA-1 have been determined and compared to calculations based on the eikonal reaction theory. The reduction factors for the single-particle strength with respect to the independent-particle model were obtained and compared to state-of-the-art ab initio predictions. The results do not show any significant dependence on proton-neutron asymmetry.http://lup.lub.lu.se/record/613b71e4-25ef-4711-b80e-2359dca8b2adhttp://dx.doi.org/10.1103/PhysRevLett.120.052501pmid:29481189scopus:85041303967engPhysical Review Letters; 120(5), no 052501 (2018)ISSN: 0031-9007Subatomic PhysicsQuasifree (p, 2p) Reactions on Oxygen Isotopes : Observation of Isospin Independence of the Reduced Single-Particle Strengthcontributiontojournal/articleinfo:eu-repo/semantics/articletext