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Author Orce, J.N. et al; Rubio, B.
Title Search for two-phonon octupole excitations in Gd-146 Type Journal Article
Year 2016 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 52 Issue 6 Pages 166 - 7pp
Keywords
Abstract The low-spin structure of the nearly spherical nucleus Gd-146 was studied using the Sm-144(He-4, 2n) fusion-evaporation reaction. High-statistics gamma-gamma coincidence measurements were performed at iThemba LABS with 7x10(9) gamma-gamma coincidence events recorded. Gated gamma-ray energy spectra show evidence for the 6(2)(+) -> 3(1)(-) -> 0(1)(+) cascade of E3 transitions in agreement with recent findings by Caballero and co-workers, but with a smaller branching ratio of I-gamma = 4.7(10) for the 6(2)(+) -> 3(1)(-) 1905.1 keV gamma ray. Although these findings may support octupole vibrations in spherical nuclei, sophisticated beyond mean-field calculations including angular-momentum projection are required to interpret in an appropriate way the available data due to the failure of the rotational model assumptions in this nucleus.
Address (down) [Orce, J. N.; Raju, M. Kumar; Khumalo, N. A.; Dinoko, T. S.; Easton, J.; Kheswa, N.; Herbert, M. S.; Masiteng, P. L.; Noncolela, S. P.; Shirinda, O.; Sithole, P. S.] Univ Western Cape, Dept Phys, P-B X17, ZA-7535 Bellville, South Africa, Email: jnorce@uwc.ac.za
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000378999800002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2750
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Author Olmo, G.J.; Rubiera-Garcia, D.; Sanchez-Puente, A.
Title Classical resolution of black hole singularities via wormholes Type Journal Article
Year 2016 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 76 Issue 3 Pages 143 - 6pp
Keywords
Abstract In certain extensions of General Relativity, wormholes generated by spherically symmetric electric fields can resolve black hole singularities without necessarily removing curvature divergences. This is shown by studying geodesic completeness, the behavior of time-like congruences going through the divergent region, and by means of scattering of waves off the wormhole. This provides an example of the logical independence between curvature divergences and space-time singularities, concepts very often identified with each other in the literature.
Address (down) [Olmo, Gonzalo J.; Sanchez-Puente, A.] Univ Valencia, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@csic.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000375302500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2655
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Author Olmo, G.J.; Rubiera-Garcia, D.; Sanchez-Puente, A.
Title Impact of curvature divergences on physical observers in a wormhole space-time with horizons Type Journal Article
Year 2016 Publication Classical and Quantum Gravity Abbreviated Journal Class. Quantum Gravity
Volume 33 Issue 11 Pages 115007 - 12pp
Keywords Singularities; black holes; metric-affine geometry
Abstract The impact of curvature divergences on physical observers in a black hole space-time, which, nonetheless, is geodesically complete is investigated. This space-time is an exact solution of certain extensions of general relativity coupled to Maxwell's electrodynamics and, roughly speaking, consists of two Reissner-Nordstrom (or Schwarzschild or Minkowski) geometries connected by a spherical wormhole near the center. We find that, despite the existence of infinite tidal forces, causal contact is never lost among the elements making up the observer. This suggests that curvature divergences may not be as pathological as traditionally thought.
Address (down) [Olmo, Gonzalo J.; Sanchez-Puente, A.] Univ Valencia, CSIC, Ctr Mixto, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@csic.es;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0264-9381 ISBN Medium
Area Expedition Conference
Notes WOS:000377442000010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2728
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Author Oliver, J.F.; Rafecas, M.
Title Modelling Random Coincidences in Positron Emission Tomography by Using Singles and Prompts: A Comparison Study Type Journal Article
Year 2016 Publication PLoS One Abbreviated Journal PLoS ONE
Volume 11 Issue 9 Pages e0162096 - 22pp
Keywords
Abstract Random coincidences degrade the image in Positron Emission Tomography, PET. To compensate for their degradation effects, the rate of random coincidences should be estimated. Under certain circumstances, current estimation methods fail to provide accurate results. We propose a novel method, “Singles-Prompts” (SP), that includes the information conveyed by prompt coincidences and models the pile-up. The SP method has the same structure than the well-known “Singles Rate” (SR) approach. Hence, SP can straightforwardly replace SR. In this work, the SP method has been extensively assessed and compared to two conventional methods, SR and the delayed window (DW) method, in a preclinical PET scenario using Monte-Carlo simulations. SP offers accurate estimates for the randoms rates, while SR and DW tend to overestimate the rates (similar to 10%, and 5%, respectively). With pile-up, the SP method is more robust than SR (but less than DW). At the image level, the contrast is overestimated in SR-corrected images, + 16%, while SP produces the correct value. Spill-over is slightly reduced using SP instead of SR. The DW images values are similar to those of SP except for low-statistic scenarios, where DW behaves as if randoms were not compensated for. In particular, the contrast is reduced, -16%. In general, the better estimations of SP translate into better image quality.
Address (down) [Oliver, Josep F.; Rafecas, M.] Inst Fis Corpuscular IFIC UV CSIC, Valencia, Spain, Email: josep.f.oliver@uv.es
Corporate Author Thesis
Publisher Public Library Science Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-6203 ISBN Medium
Area Expedition Conference
Notes WOS:000383255200040 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2825
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Author Nacher, E.; Rubio, B.; Algora, A.; Cano-Ott, D.; Tain, J.L.; Gadea, A.; Agramunt, J.; Gierlik, M.; Karny, M.; Janas, Z.; Roeckl, E.; Blazhev, A.; Collatz, R.; Doring, J.; Hellstrom, M.; Hu, Z.; Kirchner, R.; Mukha, I.; Plettner, C.; Shibata, M.; Rykaczewski, K.; Batist, L.; Moroz, F.; Wittmann, V.; Valiente-Dobon, J.J.
Title Observations of the Gamow-Teller resonance in the rare-earth nuclei above Gd-146 populated in beta decay Type Journal Article
Year 2016 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 93 Issue 1 Pages 014308 - 13pp
Keywords
Abstract The rare-earth region of the nuclear table around the quasi-doubly magic nucleus Gd-146 is one of the very few places in which the Gamow-Teller (GT) resonance can be populated in beta decay. The appropriate technique to study such a phenomenon is total absorption spectroscopy, thanks to which one can measure the B(GT) distribution in beta-decay experiments even when it is very fragmented and lies at high excitation energy in the daughter nucleus. Results on the GT resonance measured in the beta decay of the odd-Z, N = 83 nuclei Tb-148, Ho-150, and Tm-152 are presented in this work and compared with shell-model calculations. The tail of the resonance is clearly observed up to the limit imposed by the Q value. This observation is important in the context of the understanding of the “quenching” of the GT strength.
Address (down) [Nacher, E.; Rubio, B.; Algora, A.; Cano-Ott, D.; Tain, J. L.; Gadea, A.; Agramunt, J.] Univ Valencia, CSIC, IFIC, Valencia 46071, Spain, Email: berta.rubio@ific.uv.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000368298200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2522
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Author Moschner, K. et al; Algora, A.
Title Relativistic Coulomb excitation of Kr-88 Type Journal Article
Year 2016 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 94 Issue 5 Pages 054323 - 5pp
Keywords
Abstract To investigate the systematics of mixed-symmetry states in N = 52 isotones, a relativistic Coulomb excitation experiment was performed during the PreSPEC campaign at the GSI Helmholtzzentrum fur Schwerionenforschung to determine E2 transition strengths to 2(+) states of the radioactive nucleus Kr-88. Absolute transition rates could be measured towards the first and third 2+ states. For the latter a mixed-symmetry character is suggested on the basis of the indication for a strong M1 transition to the fully symmetric 2(1)(+) state, extending the knowledge of the N = 52 isotones below Z = 40. A comparison with the proton-neutron interacting boson model and shell-model predictions is made and supports the assignment.
Address (down) [Moschner, K.; Blazhev, A.; Jolie, J.; Warr, N.; Braun, N.; Hackstein, M.; Naqvi, F.; Reiter, P.; Rudigier, M.; Taprogge, J.; Thomas, T.; Wendt, A.] Univ Cologne, Inst Kernphys, Cologne, Germany
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000388821800005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2910
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Author Montanari, D. et al; Gadea, A.
Title Pair neutron transfer in Ni-60+Sn-116 probed via gamma-particle coincidences Type Journal Article
Year 2016 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 93 Issue 5 Pages 054623 - 6pp
Keywords
Abstract We performed a gamma-particle coincidence experiment for the Ni-60 + Sn-116 system to investigate whether the population of the two-neutron pickup channel leading to Ni-62 is mainly concentrated in the ground-state transition, as has been found in a previous work [D. Montanari et al., Phys. Rev. Lett. 113, 052501 (2014)]. The experiment has been performed by employing the PRISMA magnetic spectrometer coupled to the Advanced Gamma Tracking Array (AGATA) demonstrator. The strength distribution of excited states corresponding to the inelastic, one-and two-neutron transfer channels has been extracted. We found that in the two-neutron transfer channel the strength to excited states corresponds to a fraction (less than 24%) of the total, consistent with the previously obtained results that the 2n channel is dominated by the ground-state to ground-state transition.
Address (down) [Montanari, D.; Bazzacco, D.; Mengoni, D.; Montagnoli, G.; Recchia, F.; Scarlassara, F.; Ur, C. A.] Univ Padua, Dipartimento Fis & Astron, I-35131 Padua, Italy
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000376921400006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2705
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Author Moline, A.; Schewtschenko, J.A.; Palomares-Ruiz, S.; Boehm, C.; Baugh, C.M.
Title Isotropic extragalactic flux from dark matter annihilations: lessons from interacting dark matter scenarios Type Journal Article
Year 2016 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 08 Issue 8 Pages 069 - 23pp
Keywords dark matter simulations; dark matter theory; gamma ray theory
Abstract The extragalactic gamma-ray and neutrino emission may have a contribution from dark matter (DM) annihilations. In the case of discrepancies between observations and standard predictions, one could infer the DM pair annihilation cross section into cosmic rays by studying the shape of the energy spectrum. So far all analyses of the extragalactic DM signal have assumed the standard cosmological model (ACDM) as the underlying theory. However, there are alternative DM scenarios where the number of low-mass objects is significantly suppressed. Therefore the characteristics of the gamma-ray and neutrino emission in these models may differ from ACDM as a result. Here we show that the extragalactic isotropic signal in these alternative models has a similar energy dependence to that in ACDM, but the overall normalisation is reduced. The similarities between the energy spectra combined with the flux suppression could lead one to misinterpret possible evidence for models beyond ACDM as being due to CDM particles annihilating with a much weaker cross section than expected.
Address (down) [Moline, Angeles] Univ Tecn Lisboa, Inst Super Tecn, CFTP, Av Rovisco Pais 1, P-1049001 Lisbon, Portugal, Email: maria.moline@ist.utl.pt;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000389859100053 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2900
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Author Molina, R.; Doring, M.; Oset, E.
Title Determination of the compositeness of resonances from decays: The case of the B-s(0) -> J/Psi f(1)(1285) Type Journal Article
Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 93 Issue 11 Pages 114004 - 10pp
Keywords
Abstract We develop a method to measure the amount of compositeness of a resonance, mostly made as a bound state of two hadrons, by simultaneously measuring the rate of production of the resonance and the mass distribution of the two hadrons close to threshold. By using different methods of analysis we conclude that the method allows one to extract the value of 1-Z with about 0.1 of uncertainty. The method is applied to the case of the (B) over bar (0)(s) -> J/Psi f(1)(1285) decay, by looking at the resonance production and the mass distribution of K (K) over bar*.
Address (down) [Molina, R.; Doring, M.] George Washington Univ, Inst Nucl Studies, 725 21st St NW, Washington, DC 20052 USA, Email: oset@ific.uv.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000377303000002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2719
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Author Miranda, O.G.; Valle, J.W.F.
Title Neutrino oscillations and the seesaw origin of neutrino mass Type Journal Article
Year 2016 Publication Nuclear Physics B Abbreviated Journal Nucl. Phys. B
Volume 908 Issue Pages 436-455
Keywords
Abstract The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, has brought neutrino physics to the precision era. We note that CP effects in oscillation phenomena could be difficult to extract in the presence of unitarity violation. As a result upcoming dedicated leptonic CP violation studies should take into account the non-unitarity of the lepton mixing matrix. Restricting non-unitarity will shed light on the seesaw scale, and thereby guide us towards the new physics responsible for neutrino mass generation.
Address (down) [Miranda, O. G.] IPN, Ctr Invest & Estudios Avanzados, Dept Fis, Apdo Postal 14-740, Mexico City 07000, DF, Mexico, Email: omr@fis.cinvestav.mx
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0550-3213 ISBN Medium
Area Expedition Conference
Notes WOS:000377334000028 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2716
Permanent link to this record