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Author |
Valiente-Dobon, J.J.; Poves, A.; Gadea, A.; Fernandez-Dominguez, B. |
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Title |
Broken mirror symmetry in S-36 and Ca-36 |
Type |
Journal Article |
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Year |
2018 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
98 |
Issue |
1 |
Pages |
011302 - 5pp |
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Keywords |
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Abstract |
Shape coexistence is a ubiquitous phenomenon in the neutron-rich nuclei belonging to (or sitting at the shores of) the N = 20 island of inversion (IoI). Exact isospin symmetry predicts the same behavior for their mirrors and the existence of a proton-rich IoI around Z = 20, centered in the (surely unbound) nucleus Ca-32. In this article we show that in Ca-36 and S-36, Coulomb effects break dramatically the mirror symmetry in the excitation energies due to the different structures of the intruder and normal states. The mirror energy difference (MED) of their 2(+) states is known to be very large at – 246 keV. We reproduce this value and predict the first excited state in Ca-36 to be a 0(+) at 2.7 MeV, 250 keV below the first 2(+). In its mirror S-36 the 0(+) lies at 55keV above the 2(+) measured at 3.291 MeV. Our calculations predict a huge MED of -720 keV, that we dub the “colossal” mirror energy difference. A possible reaction mechanism to access the O-2(+) in Ca-36 will be discussed. In addition, we theoretically address the MEDs of the A = 34, T = 3 and A = 32, T = 4 mirrors. |
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Address |
[Valiente-Dobon, J. J.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, Legnaro, Italy |
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Amer Physical Soc |
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English |
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ISSN |
2469-9985 |
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Conference |
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Notes |
WOS:000439059400001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3661 |
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Permanent link to this record |
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Author |
Boso, A. et al; Gadea, A.; Huyuk, T. |
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Title |
Neutron Skin Effects in Mirror Energy Differences: The Case of Mg-23-Na-23 |
Type |
Journal Article |
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Year |
2018 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
121 |
Issue |
3 |
Pages |
032502 - 5pp |
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Keywords |
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Abstract |
Energy differences between analogue states in the T = 1/2 Mg-23-Na-23 mirror nuclei have been measured along the rotational yrast bands. This allows us to search for effects arising from isospin-symmetrybreaking interactions (ISB) and/or shape changes. Data are interpreted in the shell model framework following the method successfully applied to nuclei in the f(7/2) shell. It is shown that the introduction of a schematic ISB interaction of the same type of that used in the f(7/2) shell is needed to reproduce the data. An alternative novel description, applied here for the first time, relies on the use of an effective interaction deduced from a realistic charge-dependent chiral nucleon-nucleon potential. This analysis provides two important results: (i) The mirror energy differences give direct insight into the nuclear skin; (ii) the skin changes along the rotational bands are strongly correlated with the difference between the neutron and proton occupations of the s(1/2) “halo” orbit. |
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Address |
[Boso, A.; Lenzi, S. M.; Recchia, F.; Zuker, A. P.; John, P. R.; Mengoni, D.; Michelagnoli, C.] Univ Padua, Dipartimento Fis & Astron, I-135131 Padua, Italy, Email: alberto.boso@npl.co.uk |
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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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Edition |
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ISSN |
0031-9007 |
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Expedition |
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Conference |
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Notes |
WOS:000439286800004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3668 |
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Author |
Bazeia, D.; Marques, M.A.; Olmo, G.J. |
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Title |
Small and hollow magnetic monopoles |
Type |
Journal Article |
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Year |
2018 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
98 |
Issue |
2 |
Pages |
025017 - 8pp |
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Keywords |
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Abstract |
We deal with the presence of magnetic monopoles in a non-Abelian model that generalizes the standard 't Hooft-Polyakov model in three spatial dimensions. We investigate the energy density of the static and spherically symmetric solutions to find first order differential equations that solve the equations of motion. The system is further studied and two distinct classes of solutions are obtained, one that can also be described by analytical solutions and is called a small monopole, since it is significantly smaller than the standard 't Hooft-Polyakov monopole. The other type of structure is the hollow monopole, since the energy density is endowed with a hole at its core. The hollow monopole can be smaller or larger than the standard monopole, depending on the value of the parameter that controls the magnetic permeability of the model. |
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Address |
[Bazeia, D.; Marques, M. A.; Olmo, Gonzalo J.] Univ Fed Paraiba, Dept Fis, BR-58051970 Joao Pessoa, Paraiba, Brazil |
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Publisher |
Amer Physical Soc |
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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 |
2470-0010 |
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:000439545000007 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3672 |
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Permanent link to this record |
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Author |
Barbero, J.F.; Ferreiro, A.; Navarro-Salas, J.; Villaseñor, E.J.S. |
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Title |
Adiabatic expansions for Dirac fields, renormalization, and anomalies |
Type |
Journal Article |
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Year |
2018 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
98 |
Issue |
2 |
Pages |
025016 - 11pp |
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Keywords |
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Abstract |
We introduce an iterative method to univocally determine the adiabatic expansion of the modes of Dirac fields in spatially homogeneous external backgrounds. We overcome the ambiguities found in previous studies and use this new procedure to improve the adiabatic regularization/renormalization scheme. We provide details on the application of the method for Dirac fields living in a four-dimensional Friedmann-Lemaitre-Robertson-Walker spacetime with a Yukawa coupling to an external scalar field. We check the consistency of our proposal by working out the conformal anomaly. We also analyze a two-dimensional Dirac field in Minkowski space coupled to a homogeneous electric field and reproduce the known results on the axial anomaly. The adiabatic expansion of the modes given here can be used to properly characterize the allowed physical states of the Dirac fields in the above external backgrounds. |
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Address |
[Barbero G, J. Fernando] CSIC, Inst Estruct Mat, E-28006 Madrid, Spain, Email: fbarbero@iem.cfmac.csic.es; |
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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 |
2470-0010 |
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:000439414000006 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
3673 |
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Permanent link to this record |
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Author |
n_TOF Collaboration (Damone, L. et al); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A. |
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Title |
Be-7 (n,p)Li-7 Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN |
Type |
Journal Article |
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Year |
2018 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
121 |
Issue |
4 |
Pages |
042701 - 7pp |
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Keywords |
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Abstract |
We report on the measurement of the Be-7(n,p)Li-7 cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n_TOF facility at CERN. This reaction plays a key role in the lithium yield of the big bang nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements performed on this reaction did not cover the energy window of interest for BBN, and they showed a large discrepancy between each other. The measurement was performed with a Si telescope and a high-purity sample produced by implantation of a Be-7 ion beam at the ISOLDE facility at CERN. While a significantly higher cross section is found at low energy, relative to current evaluations, in the region of BBN interest, the present results are consistent with the values inferred from the time-reversal Li-7(p,n)Be-7 reaction, thus yielding only a relatively minor improvement on the so-called cosmological lithium problem. The relevance of these results on the near-threshold neutron production in the p + Li-7 reaction is also discussed. |
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Address |
[Damone, L.; Barbagallo, M.; Mastromarco, M.; Colonna, N.; Mazzone, A.; Tagliente, G.; Variale, V.] Ist Nazl Fis Nucl, Sez Bari, Bari, Italy, Email: alberto.mengoni@enea.it |
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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 |
0031-9007 |
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:000439547100004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3674 |
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Permanent link to this record |