| Records |
| Author |
Krzysiek, M. et al; Gadea, A.; Huyuk, T.; Barrientos, D. |
| Title |
Study of the soft dipole modes in Ce-140 via inelastic scattering of O-17 |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physica Scripta |
Abbreviated Journal |
Phys. Scr. |
| Volume |
89 |
Issue |
5 |
Pages  |
054016 - 6pp |
| Keywords |
pygmy dipole resonances; inelastic scattering; AGATA detector; gamma spectroscopy |
| Abstract |
The main aim of this study was a deeper understanding of the nuclear structure properties of the soft dipole modes in Ce-140, excited via inelastic scattering of weakly bound O-17 projectiles. An important aim was to investigate the 'splitting' of the PDR into two parts: a low-energy isoscalar component dominated by neutron-skin oscillations and a higher-energy component lying on the tail of the giant dipole resonance of a rather isovector character. This was already observed for this nucleus, investigated in (alpha, alpha') and (gamma,gamma') experiments. The experiment was performed at Laboratori Nazionali di Legnaro, Italy. Inelastic scattering of O-17 ion beam at 20 MeV A(-1) was used to excite the resonance modes in the Ce-140 target. Gamma-rays were registered by five triple clusters of AGATA-Demonstrator and nine large volume scintillators (LaBr3). The scattered O-17 ions were identified by two Delta E – E Si telescopes of the TRACE array mounted inside the scattering chamber. The telescopes consisted of two segmented Si-pad detectors, each of 60 pixels. Very preliminary data have shown a strong domination of the E1 transitions in the 'pygmy' region with a character more similar to the one obtained in alpha scattering experiment. |
| Address |
[Krzysiek, M.; Kmiecik, M.; Maj, A.; Bednarczyk, P.; Ciemala, M.; Fornal, B.; Grebosz, J.; Mazurek, K.; Meczynski, W.; Zieblinski, M.] Polish Acad Sci, H Niewodniczanski Inst Nucl Phys, Krakow, Poland, Email: mateusz.krzysiek@ifj.edu.pl |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
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 |
0031-8949 |
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:000335785300016 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1790 |
| Permanent link to this record |
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| Author |
Liang, W.H.; Xiao, C.W.; Oset, E. |
| Title |
Baryon states with open beauty in the extended local hidden gauge approach |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
89 |
Issue |
5 |
Pages |
054023 - 15pp |
| Keywords |
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| Abstract |
In this paper, we examine the interaction of (B) over barN, (B) over bar Delta, (B) over bar *N, and (B) over bar*Delta states, together with their coupled channels, by using a mapping from the light meson sector. The assumption that the heavy quarks act as spectators at the quark level automatically leads us to the results of the heavy quark spin symmetry for pion exchange and reproduces the results of the Weinberg Tomozawa term, coming from light vector exchanges in the extended local hidden gauge approach. With this dynamics we look for states dynamically generated from the interaction and find two states with nearly zero width, which we associate to the A(b)(5912) and A(b)(5920) states. The states couple mostly to (B) over bar *N, which are degenerate with the Weinberg Tomozawa interaction. The difference of masses between these two states, with J = 1/2 and 3/2, respectively, is due to pion exchange connecting these states to intermediate (B) over barN states. In addition to these two A(b) states, we find three more states with I = 0, one of them nearly degenerate in two states of J = 1/2, 3/2. Furthermore, we also find eight more states in I = 1, two of them degenerate in J = 1/2, 3/2, and another two degenerate in J = 1/2, 3/2, 5/2. |
| Address |
[Liang, W. H.] Guangxi Normal Univ, Dept Phys, Guilin 541004, Peoples R China, Email: liangwh@gxnu.edu.cn |
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Thesis |
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| Publisher |
Amer 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 |
1550-7998 |
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:000334303600003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1761 |
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| Author |
Gomez Dumm, D.; Noguera, S.; Scoccola, N.N.; Scopetta, S. |
| Title |
Pion distribution amplitude and the pion-photon transition form factor in a nonlocal chiral quark model |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
89 |
Issue |
5 |
Pages |
054031 - 14pp |
| Keywords |
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| Abstract |
We study the pion distribution amplitude (pi DA) in the context of a nonlocal chiral quark model. The corresponding Lagrangian reproduces the phenomenological values of the pion mass and decay constant, as well as the momentum dependence of the quark propagator obtained in lattice calculations. It is found that the obtained pi DA has two symmetric maxima, which arise from the new contributions generated by the nonlocal character of the interactions. This pi DA is applied to leading order and next-to-leading order calculations of the pion-photon transition form factor. Implications of the results are discussed. |
| Address |
[Gomez Dumm, D.] Univ Nacl La Plata, CONICET, IFLP, Dept Fis, RA-1900 La Plata, Argentina |
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Thesis |
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| Publisher |
Amer 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 |
1550-7998 |
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:000334304700006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1775 |
| Permanent link to this record |
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| Author |
Wendt, A. et al; Algora, A. |
| Title |
Isospin symmetry in the sd shell: Transition strengths in the neutron-deficient sd shell nucleus Ar-33 |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
| Volume |
90 |
Issue |
5 |
Pages |
054301 - 7pp |
| Keywords |
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| Abstract |
Reduced transition strengths of the deexciting transitions from the first two excited states in Ar-33 were measured in a relativistic Coulomb excitation experiment at the GSI Helmholtz center. The radioactive ion beam was produced by fragmentation of a primary Ar-36 beam on a Be-9 target followed by the selection of the reaction product of interest via the GSI Fragment Separator. The (33A)r beam hit a secondary Au-197 target with an energy of approximately 145 MeV/nucleon. An array of high-purity germanium cluster detectors and large-volume BaF2 scintillator detectors were employed for gamma-ray spectroscopy at the secondary target position. The Lund-York-Cologne Calorimeter was used to track the outgoing ions and to identify the nuclear reaction channels. For the two lowest energy excited states of Ar-33 the reduced transition strengths have been determined. With these first results the T-z = -3/2 nucleus Ar-33 is now, together with Na-21 (T-z = -1/2), the only neutron-deficient odd-A sd shell nucleus in which experimental transition strengths are available. The experimental values are compared to results of shell-model calculations which describe simultaneously mirror-energy differences and transition-strength values of mirror pairs in the sd shell in a consistent way. |
| Address |
[Wendt, A.; Taprogge, J.; Reiter, P.; Blazhev, A.; Braun, N.; Geibel, K.; Hackstein, M.; Moschner, K.; Siebeck, B.; Warr, N.] Univ Cologne, Inst Kernphys, Cologne, Germany |
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Thesis |
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| Publisher |
Amer 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 |
0556-2813 |
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:000344489100002 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2005 |
| Permanent link to this record |
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| Author |
Ledwig, T.; Martin Camalich, J.; Geng, L.S.; Vicente Vacas, M.J. |
| Title |
Octet-baryon axial-vector charges and SU(3)-breaking effects in the semileptonic hyperon decays |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
90 |
Issue |
5 |
Pages |
054502 - 16pp |
| Keywords |
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| Abstract |
The octet-baryon axial-vector charges and the g(1)/f(1) ratios measured in the semileptonic hyperon decays are studied up to O(p(3)) using the covariant baryon chiral perturbation theory with explicit decuplet contributions. We clarify the role of different low-energy constants and find a good convergence for the chiral expansion of the axial-vector charges of the baryon octet, g(1)(0), with O(p(3)) corrections typically around 20% of the leading ones. This is a consequence of strong cancellations between different next-to-leading- order terms. We show that considering only nonanalytic terms is not enough and that analytic terms appearing at the same chiral order play an important role in this description. The same effects still hold for the chiral extrapolation of the axial-vector charges and result in a rather mild quark-mass dependence. As a result, we report a determination of the leading-order chiral couplings, D = 0.623(61)(17) and F = 0.441(47)(2), as obtained from a completely consistent chiral analysis up to O(p(3)). Furthermore, we note that the appearance of an unknown low-energy constant precludes the extraction of the proton octet charge from semileptonic decay data alone, which is relevant for an analysis of the composition of the proton spin. |
| Address |
[Ledwig, T.; Vicente Vacas, M. J.] Univ Valencia, CSIC, Inst Invest Paterna, Dept Fis Teor, Paterna 46980, Spain, Email: ledwig@ific.uv.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Amer 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 |
1550-7998 |
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:000341264600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1899 |
| Permanent link to this record |
