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Author |
Pino, F.; Roe, N.; Orero, A.; Falcon, C.; Rojas, S.; Benlloch, J.M.; Ros, D.; Pavia, J. |
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Title |
Development of a variable-radius pinhole SPECT system with a portable gamma camera |
Type |
Journal Article |
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Year |
2011 |
Publication  |
Revista Española de Medicina Nuclear |
Abbreviated Journal |
Rev. Esp. Med. Nucl. |
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Volume |
30 |
Issue |
5 |
Pages |
286-291 |
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Keywords |
SPECT; Small animal; Pinhole; Portable gamma camera; Continuous scintillator |
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Abstract |
Objective: To develop a small-animal SPECT system using a low cost commercial portable gamma camera equipped with a pinhole collimator, a continuous scintillation crystal and a position-sensitive photomultiplier tube. Material and methods: The gamma camera was attached to a variable radius system, which enabled us to optimize sensitivity and resolution by adjusting the radius of rotation to the size of the object. To investigate the capability of the SPECT system for small animal imaging, the dependence of resolution and calibration parameters on radius was assessed and acquisitions of small phantoms and mice were carried out. Results: Resolution values, ranging from 1.0 mm for a radius of 21.4 mm and 1.4 mm for a radius of 37.2 mm were obtained, thereby justifying the interest of a variable radius SPECT system. Conclusions: The image quality of phantoms and animals were satisfactory, thus confirming the usefulness of the system for small animal SPECT imaging. |
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Address |
[Pino, F; Roe, N; Ros, D] Univ Barcelona, Fac Med, Unitat Biofis, Barcelona 7, Spain, Email: fpino@iconcologia.net |
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Elsevier Science Inc |
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English |
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ISSN |
0212-6982 |
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Notes |
WOS:000294659400004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
753 |
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Author |
Ikeno, N.; Kimura, R.; Yamagata-Sekihara, J.; Nagahiro, H.; Jido, D.; Itahashi, K.; Geng, L.S.; Hirenzaki, S. |
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Title |
Precision Spectroscopy of Deeply Bound Pionic Atoms and Partial Restoration of Chiral Symmetry in Medium |
Type |
Journal Article |
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Year |
2011 |
Publication |
Progress of Theoretical Physics |
Abbreviated Journal |
Prog. Theor. Phys. |
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Volume |
126 |
Issue |
3 |
Pages |
483-509 |
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Abstract |
We study theoretically the formation spectra of deeply bound pionic atoms expected to be observed by experiments with high energy resolution at RIBF/RIKEN, and we discuss in detail the possibilities to extract new information on the pion properties at finite density from the observed spectra, which may provide information on partial restoration of chiral symmetry in medium. We find that the non-yrast pionic states such as 2s are expected to be seen in the (d,(3)He) spectra, which will be helpful to reduce uncertainties of the theoretical calculations in the neutron wave functions in nucleus. The observation of the 2s state with the ground is state is also helpful to reduce the experimental uncertainties associated in the calibration of the absolute excitation energy. We find that the nuclear densities probed by atomic pions are quite stable and almost constant for various atomic states and various nuclei. Effects of the pion wave function renormalization to the formation spectra are also evaluated. |
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Address |
[Ikeno, N; Kimura, R; Nagahiro, H; Hirenzaki, S] Nara Womens Univ, Dept Phys, Nara 6308506, Japan |
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Progress Theoretical Physics Publication Office |
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English |
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ISSN |
0033-068x |
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Notes |
WOS:000295760400008 |
Approved |
no |
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Is ISI |
no |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
784 |
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Author |
Fujita, Y.; Rubio, B.; Gelletly, W. |
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Title |
Spin-isospin excitations probed by strong, weak and electro-magnetic interactions |
Type |
Journal Article |
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Year |
2011 |
Publication |
Progress in Particle and Nuclear Physics |
Abbreviated Journal |
Prog. Part. Nucl. Phys. |
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Volume |
66 |
Issue |
3 |
Pages |
549-606 |
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Keywords |
Gamow-Teller transitions; beta decay; Charge-exchange reactions; Isospin symmetry; High resolution; Proton-rich nuclei |
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Abstract |
Gamow-Teller (GT) transitions are the most common weak interaction processes of spin-isospin (sigma tau) type in atomic nuclei. They are of interest not only in nuclear physics but also in astrophysics; they play an important role in supernovae explosions and nucleosynthesis. The direct study of weak decay processes, however, gives relatively limited information about GT transitions and the states excited via GT transitions (GT states); beta decay can only access states at excitation energies lower than the decay Q-value, and neutrino-induced reactions have very small cross-sections. However, one should note that beta decay has a direct access to the absolute GT transition strengths B(GT) from a study of half-lives, Q(beta)-values and branching ratios. They also provide information on GT transitions in nuclei far-from-stability. Studies of M1 gamma transitions provide similar information. In contrast, the complementary charge-exchange (CE) reactions, such as the (p, n) or ((3)He, t) reactions at intermediate beam energies and 0 degrees, can selectively excite GT states up to high excitation energies in the final nucleus. It has been found empirically that there is a close proportionality between the cross-sections at 0 degrees and the transition strengths B(GT) in these CE reactions. Therefore, CE reactions are useful tools to study the relative values of B(GT) strengths up to high excitation energies. In recent ((3)He, t) measurements, one order-of-magnitude improvement in the energy resolution has been achieved. This has made it possible to make one-to-one comparisons of GT transitions studied in CE reactions and beta decays. Thus GT strengths in ((3)He, t) reactions can be normalised by the beta-decay values. In addition, comparisons with closely related M1 transitions studied in gamma decay or electron inelastic scattering [(e, e')1, and furthermore with “spin” M I transitions that can be studied by proton inelastic scattering [(p, p')[ have now been made possible. In these comparisons, the isospin quantum number T and associated symmetry structure in the same mass A nuclei (isobars) play a key role. Isospin symmetry can extend our scope even to the structures of unstable nuclei that are far from reach at present unstable beam factories. |
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Address |
[Fujita, Y] Osaka Univ, Dept Phys, Osaka 5600043, Japan, Email: fujita@rcnp.osaka-u.ac.jp |
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Publisher |
Elsevier Science Bv |
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English |
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ISSN |
0146-6410 |
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Notes |
WOS:000292473100003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
692 |
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Author |
Pastor, S. |
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Title |
Light Neutrinos in Cosmology |
Type |
Journal Article |
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Year |
2011 |
Publication |
Physics of Particles and Nuclei |
Abbreviated Journal |
Phys. Part. Nuclei |
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Volume |
42 |
Issue |
4 |
Pages |
628-640 |
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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. |
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Address |
Univ Valencia, CSIC, Inst Fis Corpuscular, Ed Inst Invest, Valencia 40071, Spain |
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Thesis |
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Publisher |
Maik Nauka/Interperiodica/Springer |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Abbreviated Series Title |
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Edition |
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ISSN |
1063-7796 |
ISBN |
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Notes |
WOS:000300084900011 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
906 |
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Author |
Mondragon, A.; Mondragon, M.; Peinado, E. |
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Title |
Neutrino Masses, Mixings, and FCNC's in an S(3) Flavor Symmetric Extension of the Standard Model |
Type |
Journal Article |
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Year |
2011 |
Publication |
Physics of Atomic Nuclei |
Abbreviated Journal |
Phys. Atom. Nuclei |
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Volume |
74 |
Issue |
7 |
Pages |
1046-1054 |
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Keywords |
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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. |
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Address |
[Mondragon, A; Mondragon, M] Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico, Email: mondra@fisica.unam.mx |
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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 |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
723 |
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