Records |
Author |
Gillam, J.E.; Solevi, P.; Oliver, J.F.; Rafecas, M. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Simulated one-pass list-mode: an approach to on-the-fly system matrix calculation |
Type |
Journal Article |
Year |
2013 |
Publication |
Physics in Medicine and Biology |
Abbreviated Journal |
Phys. Med. Biol. |
Volume |
58 |
Issue |
7 |
Pages |
2377-2394 |
Keywords |
|
Abstract |
In the development of prototype systems for positron emission tomography a valid and robust image reconstruction algorithm is required. However, prototypes often employ novel detector and system geometries which may change rapidly under optimization. In addition, developing systems generally produce highly granular, or possibly continuous detection domains which require some level of on-the-fly calculation for retention of measurement precision. In this investigation a new method of on-the-fly system matrix calculation is proposed that provides advantages in application to such list-mode systems in terms of flexibility in system modeling. The new method is easily adaptable to complicated system geometries and available computational resources. Detection uncertainty models are used as random number generators to produce ensembles of possible photon trajectories at image reconstruction time for each datum in the measurement list. However, the result of this approach is that the system matrix elements change at each iteration in a non-repetitive manner. The resulting algorithm is considered the simulation of a one-pass list (SOPL) which is generated and the list traversed during image reconstruction. SOPL alters the system matrix in use at each iteration and so behavior within the maximum likelihood-expectation maximization algorithm was investigated. A two-pixel system and a small two dimensional imaging model are used to illustrate the process and quantify aspects of the algorithm. The two-dimensional imaging system showed that, while incurring a penalty in image resolution, in comparison to a non-random equal-computation counterpart, SOPL provides much enhanced noise properties. In addition, enhancement in system matrix quality is straightforward (by increasing the number of samples in the ensemble) so that the resolution penalty can be recovered when desired while retaining improvement in noise properties. Finally the approach is tested and validated against a standard (highly accurate) system matrix using experimental data from a prototype system-the AX-PET. |
Address |
[Gillam, J. E.; Solevi, P.; Oliver, J. F.; Rafecas, M.] Univ Valencia, CSIC, IFIC, Inst Fis Corpuscular, Valencia, Spain, Email: john.gillam@ific.uv.es |
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 |
0031-9155 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000316181300024 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
1370 |
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.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; 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.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; 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 ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC |
Type |
Journal Article |
Year |
2013 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
Volume |
73 |
Issue |
3 |
Pages |
2305 - 34pp |
Keywords |
|
Abstract |
The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of root s = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K-s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5 % for central isolated hadrons and 1-3 % for the final calorimeter jet energy scale. |
Address |
SUNY Albany, Albany, NY 12222 USA |
Corporate Author |
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Thesis |
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Publisher |
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 |
1434-6044 |
ISBN |
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Medium |
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Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000318290600002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1428 |
Permanent link to this record |
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Author |
Hernandez, E.; Nieves, J.; Vicente Vacas, M.J. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Single pion production in neutrino-nucleus scattering |
Type |
Journal Article |
Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
87 |
Issue |
11 |
Pages |
113009 - 11pp |
Keywords |
|
Abstract |
We study 1 pi production in both charged and neutral current neutrino-nucleus scattering for neutrino energies below 2 GeV. We use a theoretical model for one pion production at the nucleon level that we correct for medium effects. The results are incorporated into a cascade program that apart from production also includes the pion final state interaction inside the nucleus. Besides, in some specific channels coherent pi production is also possible and we evaluate its contribution as well. Our results for total and differential cross sections are compared with recent data from the MiniBooNE Collaboration. The model provides an overall acceptable description of the data, better for neutral-current than for charged-current channels, although the theory is systematically below the data. Differential cross sections, folded with the full neutrino flux, show that most of the missing pions lie in the forward direction and at high energies. |
Address |
[Hernandez, E.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain |
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 |
|
Area |
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Expedition |
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Conference |
|
Notes |
WOS:000320769600004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
|
Call Number |
IFIC @ pastor @ |
Serial |
1485 |
Permanent link to this record |
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Author |
Davesne, D.; Pastore, A.; Navarro, J. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Skyrme effective pseudopotential up to the next-to-next-to-leading order |
Type |
Journal Article |
Year |
2013 |
Publication |
Journal of Physics G |
Abbreviated Journal |
J. Phys. G |
Volume |
40 |
Issue |
9 |
Pages |
095104 - 8pp |
Keywords |
|
Abstract |
The explicit form of the next-to-next-to-leading order ((NLO)-L-2) of the Skyrme effective pseudopotential compatible with all required symmetries and especially with gauge invariance is presented in a Cartesian basis. It is shown in particular that for such a pseudopotential there is no spin-orbit contribution and that the D-wave term suggested in the original Skyrme formulation does not satisfy the invariance properties. The six new (NLO)-L-2 terms contribute to both the equation of state and the Landau parameters. These contributions to symmetric nuclear matter are given explicitly and discussed. |
Address |
[Davesne, D.] Univ Lyon, F-69622 Lyon, France, Email: davesne@ipnl.in2p3.fr |
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 |
0954-3899 |
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:000323135200010 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1558 |
Permanent link to this record |
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Author |
Antonelli, V.; Miramonti, L.; Pena-Garay, C.; Serenelli, A. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Solar Neutrinos |
Type |
Journal Article |
Year |
2013 |
Publication |
Advances in High Energy Physics |
Abbreviated Journal |
Adv. High. Energy Phys. |
Volume |
2013 |
Issue |
|
Pages |
351926 - 34pp |
Keywords |
|
Abstract |
The study of solar neutrinos has given a fundamental contribution both to astroparticle and to elementary particle physics, offering an ideal test of solar models and offering at the same time relevant indications on the fundamental interactions among particles. After reviewing the striking results of the last two decades, which were determinant to solve the long standing solar neutrino puzzle and refine the Standard Solar Model, we focus our attention on the more recent results in this field and on the experiments presently running or planned for the near future. The main focus at the moment is to improve the knowledge of the mass and mixing pattern and especially to study in detail the lowest energy part of the spectrum, which represents most of the solar neutrino spectrum but is still a partially unexplored realm. We discuss this research project and the way in which present and future experiments could contribute to make the theoretical framework more complete and stable, understanding the origin of some “anomalies” that seem to emerge from the data and contributing to answer some present questions, like the exact mechanism of the vacuum to matter transition and the solution of the so-called solar metallicity problem. |
Address |
Univ Milan, Dipartimento Fis, I-20133 Milan, Italy, Email: vito.antonelli@mi.infn.it |
Corporate Author |
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Thesis |
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Publisher |
Hindawi Publishing Corporation |
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 |
1687-7357 |
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:000316881700001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1392 |
Permanent link to this record |
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Author |
Perez, A.; Romanelli, A. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Spatially Dependent Decoherence and Anomalous Diffussion of Quantum Walks |
Type |
Journal Article |
Year |
2013 |
Publication |
Journal of Computational and Theoretical Nanoscience |
Abbreviated Journal |
J. Comput. Theor. Nanosci. |
Volume |
10 |
Issue |
7 |
Pages |
1591-1595 |
Keywords |
Decoherence; Quantum Walk; Non-Translational Invariance |
Abstract |
We analyze the long time behavior of a discrete time quantum walk subject to decoherence with a strong spatial dependence, acting on one half of the lattice. We show that, except for limiting cases on the decoherence parameter, the quantum walk at late times behaves sub-ballistically, meaning that the characteristic features of the quantum walk are not completely spoiled. Contrarily to expectations, the asymptotic behavior is non Markovian, and depends on the amount of decoherence. This feature can be clearly shown on the long time value of the Generalized Chiral Distribution (GCD). |
Address |
[Perez, A.] Univ Valencia, Dept Fis Teor, CSIC, E-46100 Burjassot, Spain |
Corporate Author |
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Thesis |
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Publisher |
Amer Scientific Publishers |
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 |
1546-1955 |
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:000322605800007 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1528 |
Permanent link to this record |
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Author |
Navarro, J.; Polls, A. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Spin instabilities of infinite nuclear matter and effective tensor interactions |
Type |
Journal Article |
Year |
2013 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
87 |
Issue |
4 |
Pages |
044329 - 11pp |
Keywords |
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Abstract |
We study the effects of the tensor force, present in modern effective nucleon-nucleon interactions, in the spin instability of nuclear and neutron matter. Stability conditions of the system against certain very low energy excitation modes are expressed in terms of Landau parameters. It is shown that in the spin case, the stability conditions are equivalent to the condition derived from the spin susceptibility, which is obtained as the zero-frequency and long-wavelength limit of the spin response function calculated in the random phase approximation. Zero-range forces of the Skyrme type and finite-range forces of M3Y and Gogny type are analyzed. It is shown that for the Skyrme forces considered, the tensor effects are sizable and tend to increase the spin instability, which appears at smaller densities than in the case that the tensor is not taken into account. On the contrary, the tensor contribution of finite-range forces to the spin susceptibility is small or negligible for both isospin channels of symmetric nuclear matter as well as for neutron matter. A comparison with the spin susceptibility provided by realistic interactions is also presented. |
Address |
Univ Valencia, Inst Fis Corpuscular, CSIC, E-46071 Valencia, Spain |
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 |
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:000317866200005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
1408 |
Permanent link to this record |
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Author |
D'Ambrosio, G.; Greynat, D.; Vulvert, G. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Standard model and new physics contributions to K (L) and K (S) into four leptons |
Type |
Journal Article |
Year |
2013 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
Volume |
73 |
Issue |
12 |
Pages |
2678 - 10pp |
Keywords |
|
Abstract |
We study the K (L) and K (S) decays into four leptons (, , ) where we use a form factor motivated by vector meson dominance, and show the dependence of the branching ratios and spectra from the slopes. A precise determination of short-distance contribution to K (L) ->mu μis affected by our ignorance on the sign of the amplitude but we show a possibility to measure the sign of this amplitude by studying K (L) and K (S) decays in four leptons. We also investigate the effect of New Physics contributions for these decays. |
Address |
[D'Ambrosio, Giancarlo; Greynat, David] Ist Nazl Fis Nucl, Sez Napoli, I-80126 Naples, Italy, Email: gdambros@na.infn.it; |
Corporate Author |
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Thesis |
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Publisher |
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 |
1434-6044 |
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:000328342900001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1661 |
Permanent link to this record |
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Author |
Tortola, M. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Status of three-neutrino oscillation parameters |
Type |
Journal Article |
Year |
2013 |
Publication |
Fortschritte der Physik-Progress of Physics |
Abbreviated Journal |
Fortschritte Phys.-Prog. Phys. |
Volume |
61 |
Issue |
4-5 |
Pages |
427-440 |
Keywords |
Neutrino mass and mixing; neutrino oscillations; solar and atmospheric neutrinos; reactor and accelerator neutrinos |
Abstract |
Here we review the current status of global fits to neutrino oscillation data within the three-flavour framework. In our analysis we include the most recent data from solar and atmospheric neutrino experiments as well as the latest results from the long-baseline accelerator neutrino experiments and the recent measurements of reactor neutrino disappearance reported by Double Chooz, Daya Bay and RENO. We present updated determinations for the two neutrino mass splittings and the three mixing angles responsible for neutrino oscillations that, for the first time, have all been measured with 1 sigma accuracies ranging from 3 to 15%. A weak sensitivity for the CP violating phase is also reported from the global analysis. |
Address |
Univ Valencia, Inst Fis Corpuscular, AHEP Grp, CSIC, Valencia 46071, Spain, Email: mariam@ific.uv.es |
Corporate Author |
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Thesis |
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Publisher |
Wiley-V C H Verlag Gmbh |
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 |
0015-8208 |
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:000317019900005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
1411 |
Permanent link to this record |
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Author |
Tolos, L.; Cabrera, D.; Garcia-Recio, C.; Molina, R.; Nieves, J.; Oset, E.; Ramos, A.; Romanets, O.; Salcedo, L.L. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
Strangeness and charm in nuclear matter |
Type |
Journal Article |
Year |
2013 |
Publication |
Nuclear Physics A |
Abbreviated Journal |
Nucl. Phys. A |
Volume |
914 |
Issue |
|
Pages |
461-471 |
Keywords |
Strange mesons; Transparency ratio; Dynamically-generated baryon resonances; Open charm in matter; D-mesic nuclei |
Abstract |
The properties of strange (K, (K) over bar and (K) over bar*) and open-charm (D, (D) over bar and D*) mesons in dense matter are studied using a unitary approach in coupled channels for meson-baryon scattering. In the strangeness sector, the interaction with nucleons always comes through vector-meson exchange, which is evaluated by chiral and hidden gauge Lagrangians. For the interaction of charmed mesons with nucleons we extend the SU(3) Weinberg-Tomozawa Lagrangian to incorporate spin-flavor symmetry and implement a suitable flavor symmetry breaking. The in-medium solution for the scattering amplitude accounts for Pauli blocking effects and meson self-energies. On one hand, we obtain the K, (K) over bar and (K) over bar* spectral functions in the nuclear medium and study their behaviour at finite density, temperature and momentum. We also make an estimate of the transparency ratio of the gamma A -> K+ K*(-) A' reaction, which we propose as a tool to detect in-medium modifications of the (K) over bar* meson. On the other hand, in the charm sector, several resonances with negative parity are generated dynamically by the s-wave interaction between pseudoscalar and vector meson multiplets with 1/2(+) and 3/2(+) baryons. The properties of these states in matter are analyzed and their influence on the open-charm meson spectral functions is studied. We finally discuss the possible formation of D-mesic nuclei at FAIR energies. |
Address |
[Tolos, Laura] Fac Ciencies, Inst Ciencias Espacio IEEC CSIC, E-08193 Bellaterra, Barcelona, Spain, Email: tolos@ice.csic.es |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
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 |
0375-9474 |
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:000324847700066 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1598 |
Permanent link to this record |