LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 25

Search options

  1. Article ; Online: Broad resonances in light nuclei studied with β- and γ-spectroscopy

    Fynbo H. O. U.

    EPJ Web of Conferences, Vol 66, p

    2014  Volume 07006

    Abstract: Recent work on broad nuclear resonances in 12C are discussed. An attempt is made to formulate pressing currently open questions, which should be adressed in future studies. A new method for identifying and studying broad resonances is presented, and ... ...

    Abstract Recent work on broad nuclear resonances in 12C are discussed. An attempt is made to formulate pressing currently open questions, which should be adressed in future studies. A new method for identifying and studying broad resonances is presented, and first results discussed.
    Keywords Physics ; QC1-999 ; Science ; Q
    Language English
    Publishing date 2014-03-01T00:00:00Z
    Publisher EDP Sciences
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  2. Article ; Online: Emergence of Clusters: Halos, Efimov States, and Experimental Signals.

    Hove, D / Garrido, E / Sarriguren, P / Fedorov, D V / Fynbo, H O U / Jensen, A S / Zinner, N T

    Physical review letters

    2018  Volume 120, Issue 5, Page(s) 52502

    Abstract: We investigate the emergence of halos and Efimov states in nuclei by use of a newly designed model that combines self-consistent mean-field and three-body descriptions. Recent interest in neutron heavy calcium isotopes makes ^{72}Ca (^{70}Ca+n+n) an ... ...

    Abstract We investigate the emergence of halos and Efimov states in nuclei by use of a newly designed model that combines self-consistent mean-field and three-body descriptions. Recent interest in neutron heavy calcium isotopes makes ^{72}Ca (^{70}Ca+n+n) an ideal realistic candidate on the neutron dripline, and we use it as a representative example that illustrates our broadly applicable conclusions. By smooth variation of the interactions we simulate the crossover from well-bound systems to structures beyond the threshold of binding, and find that halo configurations emerge from the mean-field structure for three-body binding energy less than ∼100  keV. Strong evidence is provided that Efimov states cannot exist in nuclei. The structure that bears the most resemblance to an Efimov state is a giant halo extending beyond the neutron-core scattering length. We show that the observable large-distance decay properties of the wave function can differ substantially from the bulk part at short distances, and that this evolution can be traced with our combination of few- and many-body formalisms. This connection is vital for interpretation of measurements such as those where an initial state is populated in a reaction or by a beta decay.
    Language English
    Publishing date 2018-02-02
    Publishing country United States
    Document type Journal Article
    ZDB-ID 208853-8
    ISSN 1079-7114 ; 0031-9007
    ISSN (online) 1079-7114
    ISSN 0031-9007
    DOI 10.1103/PhysRevLett.120.052502
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 58/153: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Book ; Online: New experimental $^{23}$Na($\alpha,p$)$^{26}$Mg Reaction Rate for Massive Star and Type-Ia Supernova models

    Hubbard, N. J. / Diget, C. Aa. / Fox, S. P. / Fynbo, H. O. U. / Howard, A. M. / Kirsebom, O. S. / Laird, A. M. / Munch, M. / Parikh, A. / Pignatari, M. / Tomlinson, J. R.

    2021  

    Abstract: The $^{23}$Na($\alpha,p$)$^{26}$Mg reaction has been identified as having a significant impact on the nucleosynthesis of several nuclei between Ne and Ti in type-Ia supernovae, and of $^{23}$Na and $^{26}$Al in massive stars. The reaction has been ... ...

    Abstract The $^{23}$Na($\alpha,p$)$^{26}$Mg reaction has been identified as having a significant impact on the nucleosynthesis of several nuclei between Ne and Ti in type-Ia supernovae, and of $^{23}$Na and $^{26}$Al in massive stars. The reaction has been subjected to renewed experimental interest recently, motivated by high uncertainties in early experimental data and in the statistical Hauser-Feshbach models used in reaction rate compilations. Early experiments were affected by target deterioration issues and unquantifiable uncertainties. Three new independent measurements instead are utilizing inverse kinematics and Rutherford scattering monitoring to resolve this. In this work we present directly measured angular distributions of the emitted protons to eliminate a discrepancy in the assumptions made in the recent reaction rate measurements, which results in cross sections differing by a factor of 3. We derive a new combined experimental reaction rate for the $^{23}$Na($\alpha,p$)$^{26}$Mg reaction with a total uncertainty of 30% at relevant temperatures. Using our new $^{23}$Na($\alpha,p$)$^{26}$Mg rate, the $^{26}$Al and $^{23}$Na production uncertainty is reduced to within 8%. In comparison, using the factor of 10 uncertainty previously recommended by the rate compilation STARLIB, $^{26}$Al and $^{23}$Na production was changing by more than a factor of 2. In type-Ia supernova conditions, the impact on production of $^{23}$Na is constrained to within 15%.

    Comment: 13 pages, 8 figures, 4 tables
    Keywords Nuclear Experiment ; Astrophysics - Solar and Stellar Astrophysics ; Nuclear Theory
    Subject code 306
    Publishing date 2021-03-16
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  4. Article ; Online: 23Na(α,p)26Mg Reaction Rate at Astrophysically Relevant Energies.

    Howard, A M / Munch, M / Fynbo, H O U / Kirsebom, O S / Laursen, K L / Diget, C Aa / Hubbard, N J

    Physical review letters

    2015  Volume 115, Issue 5, Page(s) 52701

    Abstract: The production of 26Al in massive stars is sensitive to the 23Na(α,p)26Mg cross section. Recent experimental data suggest the currently recommended cross sections are underestimated by a factor of ∼40. We present here differential cross sections for the ... ...

    Abstract The production of 26Al in massive stars is sensitive to the 23Na(α,p)26Mg cross section. Recent experimental data suggest the currently recommended cross sections are underestimated by a factor of ∼40. We present here differential cross sections for the 23Na(α,p)26Mg reaction measured in the energy range E(c.m.)=1.7-2.5  MeV. Concurrent measurements of Rutherford scattering provide absolute normalizations that are independent of variations in target properties. Angular distributions are measured for both p0 and p1 permitting the determination of total cross sections. The results show no significant deviation from the statistical model calculations upon which the recommended rates are based. We therefore retain the previous recommendation without the increase in cross section and resulting stellar reaction rates by a factor of 40, impacting the 26Al yield from massive stars by more than a factor of 3.
    Language English
    Publishing date 2015-07-31
    Publishing country United States
    Document type Journal Article
    ZDB-ID 208853-8
    ISSN 1079-7114 ; 0031-9007
    ISSN (online) 1079-7114
    ISSN 0031-9007
    DOI 10.1103/PhysRevLett.115.052701
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 58/153: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  5. Article ; Online: Discovery of an Exceptionally Strong β-Decay Transition of ^{20}F and Implications for the Fate of Intermediate-Mass Stars.

    Kirsebom, O S / Jones, S / Strömberg, D F / Martínez-Pinedo, G / Langanke, K / Röpke, F K / Brown, B A / Eronen, T / Fynbo, H O U / Hukkanen, M / Idini, A / Jokinen, A / Kankainen, A / Kostensalo, J / Moore, I / Möller, H / Ohlmann, S T / Penttilä, H / Riisager, K /
    Rinta-Antila, S / Srivastava, P C / Suhonen, J / Trzaska, W H / Äystö, J

    Physical review letters

    2020  Volume 123, Issue 26, Page(s) 262701

    Abstract: A significant fraction of stars between 7 and 11 solar masses are thought to become supernovae, but the explosion mechanism is unclear. The answer depends critically on the rate of electron capture on ^{20}Ne in the degenerate oxygen-neon stellar core. ... ...

    Abstract A significant fraction of stars between 7 and 11 solar masses are thought to become supernovae, but the explosion mechanism is unclear. The answer depends critically on the rate of electron capture on ^{20}Ne in the degenerate oxygen-neon stellar core. However, because of the unknown strength of the transition between the ground states of ^{20}Ne and ^{20}F, it has not previously been possible to fully constrain the rate. By measuring the transition, we establish that its strength is exceptionally large and that it enhances the capture rate by several orders of magnitude. This has a decisive impact on the evolution of the core, increasing the likelihood that the star is (partially) disrupted by a thermonuclear explosion rather than collapsing to form a neutron star. Importantly, our measurement resolves the last remaining nuclear physics uncertainty in the final evolution of degenerate oxygen-neon stellar cores, allowing future studies to address the critical role of convection, which at present is poorly understood.
    Language English
    Publishing date 2020-01-22
    Publishing country United States
    Document type Journal Article
    ZDB-ID 208853-8
    ISSN 1079-7114 ; 0031-9007
    ISSN (online) 1079-7114
    ISSN 0031-9007
    DOI 10.1103/PhysRevLett.123.262701
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 58/153: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  6. Article ; Online: ^{133}In: A Rosetta Stone for Decays of r-Process Nuclei.

    Xu, Z Y / Madurga, M / Grzywacz, R / King, T T / Algora, A / Andreyev, A N / Benito, J / Berry, T / Borge, M J G / Costache, C / De Witte, H / Fijalkowska, A / Fraile, L M / Fynbo, H O U / Gottardo, A / Halverson, C / Harkness-Brennan, L J / Heideman, J / Huyse, M /
    Illana, A / Janiak, Ł / Judson, D S / Korgul, A / Kurtukian-Nieto, T / Lazarus, I / Lică, R / Lozeva, R / Marginean, N / Marginean, R / Mazzocchi, C / Mihai, C / Mihai, R E / Morales, A I / Page, R D / Pakarinen, J / Piersa-Siłkowska, M / Podolyák, Zs / Sarriguren, P / Singh, M / Sotty, Ch / Stepaniuk, M / Tengblad, O / Turturica, A / Van Duppen, P / Vedia, V / Viñals, S / Warr, N / Yokoyama, R / Yuan, C X

    Physical review letters

    2023  Volume 131, Issue 2, Page(s) 22501

    Abstract: The β decays from both the ground state and a long-lived isomer of ^{133}In were studied at the ISOLDE Decay Station (IDS). With a hybrid detection system sensitive to β, γ, and neutron spectroscopy, the comparative partial half-lives (logft) have been ... ...

    Abstract The β decays from both the ground state and a long-lived isomer of ^{133}In were studied at the ISOLDE Decay Station (IDS). With a hybrid detection system sensitive to β, γ, and neutron spectroscopy, the comparative partial half-lives (logft) have been measured for all their dominant β-decay channels for the first time, including a low-energy Gamow-Teller transition and several first-forbidden (FF) transitions. Uniquely for such a heavy neutron-rich nucleus, their β decays selectively populate only a few isolated neutron unbound states in ^{133}Sn. Precise energy and branching-ratio measurements of those resonances allow us to benchmark β-decay theories at an unprecedented level in this region of the nuclear chart. The results show good agreement with the newly developed large-scale shell model (LSSM) calculations. The experimental findings establish an archetype for the β decay of neutron-rich nuclei southeast of ^{132}Sn and will serve as a guide for future theoretical development aiming to describe accurately the key β decays in the rapid-neutron capture (r-) process.
    Language English
    Publishing date 2023-07-28
    Publishing country United States
    Document type Journal Article
    ZDB-ID 208853-8
    ISSN 1079-7114 ; 0031-9007
    ISSN (online) 1079-7114
    ISSN 0031-9007
    DOI 10.1103/PhysRevLett.131.022501
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 58/153: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  7. Article: Distinction between sequential and direct three-body decays.

    Alvarez-Rodríguez, R / Fynbo, H O U / Jensen, A S / Garrido, E

    Physical review letters

    2008  Volume 100, Issue 19, Page(s) 192501

    Abstract: We discuss the three-body decay mechanisms of many-body resonances. Sequential decays proceed via two-body configurations after emission of the third particle. In direct decay all three particles leave their interaction regions simultaneously. The ... ...

    Abstract We discuss the three-body decay mechanisms of many-body resonances. Sequential decays proceed via two-body configurations after emission of the third particle. In direct decay all three particles leave their interaction regions simultaneously. The intermediate paths within the interaction regions are not observables and are only accessible through models. The momentum distributions carry, apart from polarization, all possible information about decay modes and resonance structure. In this context we discuss detailed results for the decay of the (9)Be(5/2(-)) resonance.
    Language English
    Publishing date 2008-05-16
    Publishing country United States
    Document type Journal Article
    ZDB-ID 208853-8
    ISSN 1079-7114 ; 0031-9007
    ISSN (online) 1079-7114
    ISSN 0031-9007
    DOI 10.1103/PhysRevLett.100.192501
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 58/153: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  8. Article: Energy distributions from three-body decaying many-body resonances.

    Alvarez-Rodríguez, R / Jensen, A S / Fedorov, D V / Fynbo, H O U / Garrido, E

    Physical review letters

    2007  Volume 99, Issue 7, Page(s) 72503

    Abstract: We compute energy distributions of three particles emerging from decaying many-body resonances. We reproduce the measured energy distributions from decays of two archetypal states chosen as the lowest 0+ and 1+ resonances in 12C populated in beta decays. ...

    Abstract We compute energy distributions of three particles emerging from decaying many-body resonances. We reproduce the measured energy distributions from decays of two archetypal states chosen as the lowest 0+ and 1+ resonances in 12C populated in beta decays. These states are dominated by sequential, through the 8Be ground state, and direct decays, respectively. These decay mechanisms are reflected in the "dynamic" evolution from small, cluster or shell-model states, to large distances, where the coordinate or momentum space continuum wave functions are accurately computed.
    Language English
    Publishing date 2007-08-17
    Publishing country United States
    Document type Journal Article
    ZDB-ID 208853-8
    ISSN 1079-7114 ; 0031-9007
    ISSN (online) 1079-7114
    ISSN 0031-9007
    DOI 10.1103/PhysRevLett.99.072503
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 58/153: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  9. Article ; Online: 11Li structural information from inclusive break-up measurements

    Fernández-García J. P. / Cubero M. / Acosta L. / Alcorta M. / Alvarez M. A. G. / Borge M. J. G. / Buchmann L. / Diget C. A. / Falou H. A. / Fulton B. R. / Fynbo H. O. U. / Galaviz D. / Gómez-Camacho J. / Kanungo R. / Lay J. A. / Madurga M. / Martel I. / Moro A. M. / Mukha I. /
    Nilsson T. / Rodríguez-Gallardo M. / Sánchez-Benítez A. M. / Shotter A. / Tengblad O. / Walden P.

    EPJ Web of Conferences, Vol 88, p

    2015  Volume 01003

    Abstract: Structure information of 11Li halo nucleus has been obtained from the inclusive break-up measurements of the 11Li+208Pb reactions at energies around the Coulomb barrier (Elab = 24.3 and 29.8 MeV). The effective break-up energy and the slope of B(E1) ... ...

    Abstract Structure information of 11Li halo nucleus has been obtained from the inclusive break-up measurements of the 11Li+208Pb reactions at energies around the Coulomb barrier (Elab = 24.3 and 29.8 MeV). The effective break-up energy and the slope of B(E1) distribution close to the threshold have been extracted from the experimental data.
    Keywords Science ; Q ; Physics ; QC1-999
    Publishing date 2015-01-01T00:00:00Z
    Publisher EDP Sciences
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  10. Article ; Online: Improved limit on direct α decay of the Hoyle state.

    Kirsebom, O S / Alcorta, M / Borge, M J G / Cubero, M / Diget, C Aa / Fraile, L M / Fulton, B R / Fynbo, H O U / Galaviz, D / Jonson, B / Madurga, M / Nilsson, T / Nyman, G / Riisager, K / Tengblad, O / Turrión, M

    Physical review letters

    2012  Volume 108, Issue 20, Page(s) 202501

    Abstract: The current evaluation of the triple-α reaction rate assumes that the α decay of the 7.65 MeV, 0+ state in 12C, commonly known as the Hoyle state, proceeds sequentially via the ground state of 8Be. This assumption is challenged by the recent ... ...

    Abstract The current evaluation of the triple-α reaction rate assumes that the α decay of the 7.65 MeV, 0+ state in 12C, commonly known as the Hoyle state, proceeds sequentially via the ground state of 8Be. This assumption is challenged by the recent identification of two direct α-decay branches with a combined branching ratio of 17(5)%. If correct, this would imply a corresponding reduction in the triple-α reaction rate with important astrophysical consequences. We have used the 11B(3He,d) reaction to populate the Hoyle state and measured the decay to three α particles in complete kinematics. We find no evidence for direct α-decay branches, and hence our data do not support a revision of the triple-α reaction rate. We obtain an upper limit of 5×10(-3) on the direct α decay of the Hoyle state at 95% C.L., which is 1 order of magnitude better than a previous upper limit.
    Language English
    Publishing date 2012-05-18
    Publishing country United States
    Document type Journal Article
    ZDB-ID 208853-8
    ISSN 1079-7114 ; 0031-9007
    ISSN (online) 1079-7114
    ISSN 0031-9007
    DOI 10.1103/PhysRevLett.108.202501
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 58/153: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top