Records |
Author |
Cederwall, B. et al; Algora, A.; Gadea, A. |
Title |
Evidence for a spin-aligned neutron-proton paired phase from the level structure of Pd-92 |
Type |
Journal Article |
Year |
2011 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
469 |
Issue |
7328 |
Pages |
68-71 |
Keywords |
|
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. |
Address |
[Cederwall, B.; Moradi, F. Ghazi; Back, T.; Johnson, A.; Blomqvist, J.; Andgren, K.; Lagergren, K.; Liotta, R.; Qi, C.; Hadinia, B.; Khaplanov, A.; Persson, A.; Sandzelius, M.] Royal Inst Technol, Dept Phys, SE-10691 Stockholm, Sweden, Email: cederwall@nuclear.kth.se |
Corporate Author |
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Thesis |
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Publisher |
Nature Publishing Group |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0028-0836 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000285921600032 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
588 |
Permanent link to this record |
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Author |
ATLAS Collaboration (Aad, G. et al); Amoros, G.; Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Escobar, C.; Ferrer, A.; Fuster, J.; Garcia, C.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Kaci, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Miñano, M.; Mitsou, V.A.; Moles-Valls, R.; Moreno Llacer, M.; Oliver Garcia, E.; Perez Garcia-Estañ, M.T.; Ros, E.; Salt, J.; Solans, C.A.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Villaplana Perez, M.; Vos, M.; Wildauer, A. |
Title |
Measurement of the inelastic proton-proton cross-section at sqrt(s)=7 TeV with the ATLAS detector |
Type |
Journal Article |
Year |
2011 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat. Commun. |
Volume |
2 |
Issue |
|
Pages |
463 - 14pp |
Keywords |
|
Abstract |
The dependence of the rate of proton-proton interactions on the centre-of-mass collision energy, root s, is of fundamental importance for both hadron collider physics and particle astrophysics. The dependence cannot yet be calculated from first principles; therefore, experimental measurements are needed. Here we present the first measurement of the inelastic proton-proton interaction cross-section at a centre-of-mass energy, root s, of 7 TeV using the ATLAS detector at the Large Hadron Collider. Events are selected by requiring hits on scintillation counters mounted in the forward region of the detector. An inelastic crosssection of 60.3 +/- 2.1 mb is measured for xi > 5x10(-6), where xi is calculated from the invariant mass, M(X), of hadrons selected using the largest rapidity gap in the event. For diffractive events, this corresponds to requiring at least one of the dissociation masses to be larger than 15.7 GeV. |
Address |
[Bechtle, P; Kuutmann, EB; Boehler, M; Ehrenfeld, W; Ferrara, V; Fischer, G; Glazov, A; Goebel, M; Fajardo, LSG; Da Costa, JGPF; Gosdzik, B; Gregor, IM; Hiller, KH; Hristova, I; Husemann, U; Belenguer, MJ; Johnert, S; Karnevskiy, M; Katzy, J; Kono, T; Lankford, AJ; Lobodzinska, E; Ludwig, D; Mattig, S; Medinnis, M; Mijovic, L; Monig, K; Naumann, T; Nozicka, M; Cavalcanti, TP; Petschull, D; Piec, SM; Placakyte, R; Qin, Z; Rubinskiy, I; Stelzer, HJ; Tackmann, K; Terwort, M; Vankov, P; Viti, M; Wildt, MA; Zhu, H] DESY, D-2000 Hamburg, Germany, Email: atlas.publications@cern.ch |
Corporate Author |
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Thesis |
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Publisher |
Nature Publishing Group |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2041-1723 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000294807200005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
758 |
Permanent link to this record |
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Author |
Mondragon, A.; Mondragon, M.; Peinado, E. |
Title |
Neutrino Masses, Mixings, and FCNC's in an S(3) Flavor Symmetric Extension of the Standard Model |
Type |
Journal Article |
Year |
2011 |
Publication |
Physics of Atomic Nuclei |
Abbreviated Journal |
Phys. Atom. Nuclei |
Volume |
74 |
Issue |
7 |
Pages |
1046-1054 |
Keywords |
|
Abstract |
By introducing three Higgs fields that are SU(2) doublets and a flavor permutational symmetry, S(3), in the theory, we extend the concepts of flavor and generations to the Higgs sector and formulate a Minimal S(3)-Invariant Extension of the Standard Model. The mass matrices of the neutrinos and charged leptons are re-parameterized in terms of their eigenvalues, then the neutrino mixing matrix, V(PMNS), is computed and exact, explicit analytical expressions for the neutrino mixing angles as functions of the masses of neutrinos and charged leptons are obtained in excellent agreement with the latest experimental data. We also compute the branching ratios of some selected flavor-changing neutral current (FCNC) processes, as well as the contribution of the exchange of neutral flavor-changing scalars to the anomaly of the magnetic moment of the muon, as functions of the masses of charged leptons and the neutral Higgs bosons. We find that the S(3) x Z(2) flavor symmetry and the strong mass hierarchy of the charged leptons strongly suppress the FCNC processes in the leptonic sector, well below the present experimental bounds by many orders of magnitude. The contribution of FCNC's to the anomaly of the muon's magnetic moment is small, but not negligible. |
Address |
[Mondragon, A; Mondragon, M] Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico, Email: mondra@fisica.unam.mx |
Corporate Author |
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Thesis |
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Publisher |
Maik Nauka/Interperiodica/Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1063-7788 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000294027000011 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
723 |
Permanent link to this record |
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Author |
Pastor, S. |
Title |
Light Neutrinos in Cosmology |
Type |
Journal Article |
Year |
2011 |
Publication |
Physics of Particles and Nuclei |
Abbreviated Journal |
Phys. Part. Nuclei |
Volume |
42 |
Issue |
4 |
Pages |
628-640 |
Keywords |
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Abstract |
Neutrinos can play an important role in the evolution of the Universe, modifying some of the cosmological observables. We describe how the precision of present cosmological data can be used to learn about neutrino properties, in particular their mass. We show how the analysis of current cosmological observations provides an upper bound on the sum of neutrino masses, with improved sensitivity from future cosmological measurements. |
Address |
Univ Valencia, CSIC, Inst Fis Corpuscular, Ed Inst Invest, Valencia 40071, Spain |
Corporate Author |
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Thesis |
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Publisher |
Maik Nauka/Interperiodica/Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1063-7796 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000300084900011 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
906 |
Permanent link to this record |
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Author |
Algora, A. et al; Jordan, D.; Tain, J.L.; Rubio, B.; Agramunt, J.; Perez-Cerdan, A.B.; Molina, F.; Caballero, L.; Nacher, E. |
Title |
Improvements on Decay Heat Summation Calculations by Means of Total Absorption Gamma-ray Spectroscopy Measurements |
Type |
Journal Article |
Year |
2011 |
Publication |
Journal of the Korean Physical Society |
Abbreviated Journal |
J. Korean Phys. Soc. |
Volume |
59 |
Issue |
2 |
Pages |
1479-1482 |
Keywords |
Decay heat; Total absorption; Trap-assisted spectroscopy |
Abstract |
The decay heat of fission products plays an important role in predictions of the heat released by nuclear fuel in reactors. In this contribution we present results of the analysis of the measurement of the beta decay of some refractory isotopes that were considered possible important contributors to the decay heat in reactors. The measurements presented here were performed at the IGISOL facility of the University of Jyvaskyla, Finland. In our measurements we have combined for the first time a Penning trap (JYFLTRAP), which was used as a high resolution isobaric separator, with a total absorption spectrometer. The results of the measurements as well as their consequences for decay heat summation calculations are discussed. |
Address |
[Algora, A; Jordan, D; Tain, JL; Rubio, B; Agramunt, J; Caballero, L; Nacher, E; Perez-Cerdan, AB; Molina, F] Univ Valencia, CSIC, IFIC, Valencia, Spain, Email: algora@ific.uv.es |
Corporate Author |
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Thesis |
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Publisher |
Korean Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0374-4884 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000294080700005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
729 |
Permanent link to this record |