| Records |
| Author |
Brzezinski, K.; Oliver, J.F.; Gillam, J.; Rafecas, M. |
| Title |
Study of a high-resolution PET system using a Silicon detector probe |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physics in Medicine and Biology |
Abbreviated Journal |
Phys. Med. Biol. |
| Volume |
59 |
Issue |
20 |
Pages |
6117-6140 |
| Keywords |
PET; high-resolution imaging; Si detectors; PET insert |
| Abstract |
A high-resolution silicon detector probe, in coincidence with a conventional PET scanner, is expected to provide images of higher quality than those achievable using the scanner alone. Spatial resolution should improve due to the finer pixelization of the probe detector, while increased sensitivity in the probe vicinity is expected to decrease noise. A PET-probe prototype is being developed utilizing this principle. The system includes a probe consisting of ten layers of silicon detectors, each a 80 x 52 array of 1 x 1 x 1 mm(3) pixels, to be operated in coincidence with a modern clinical PET scanner. Detailed simulation studies of this system have been performed to assess the effect of the additional probe information on the quality of the reconstructed images. A grid of point sources was simulated to study the contribution of the probe to the system resolution at different locations over the field of view (FOV). A resolution phantom was used to demonstrate the effect on image resolution for two probe positions. A homogeneous source distribution with hot and cold regions was used to demonstrate that the localized improvement in resolution does not come at the expense of the overall quality of the image. Since the improvement is constrained to an area close to the probe, breast imaging is proposed as a potential application for the novel geometry. In this sense, a simplified breast phantom, adjacent to heart and torso compartments, was simulated and the effect of the probe on lesion detectability, through measurements of the local contrast recovery coefficient-to-noise ratio (CNR), was observed. The list-mode ML-EM algorithm was used for image reconstruction in all cases. As expected, the point spread function of the PET-probe system was found to be non-isotropic and vary with position, offering improvement in specific regions. Increase in resolution, of factors of up to 2, was observed in the region close to the probe. Images of the resolution phantom showed visible improvement in resolution when including the probe in the simulations. The image quality study demonstrated that contrast and spill-over ratio in other areas of the FOV were not sacrificed for this enhancement. The CNR study performed on the breast phantom indicates increased lesion detectability provided by the probe. |
| Address |
[Brzezinski, K.; Oliver, J. F.; Gillam, J.; Rafecas, M.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46980 Valencia, Spain, Email: brzezinski@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 |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000343092300011 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1963 |
| Permanent link to this record |
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| Author |
Gillam, J.E.; Solevi, P.; Oliver, J.F.; Casella, C.; Heller, M.; Joram, C.; Rafecas, M. |
| Title |
Sensitivity recovery for the AX-PET prototype using inter-crystal scattering events |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physics in Medicine and Biology |
Abbreviated Journal |
Phys. Med. Biol. |
| Volume |
59 |
Issue |
15 |
Pages |
4065-4083 |
| Keywords |
positron emission tomography (PET); inter-crystal scattering; sensitivity |
| Abstract |
The development of novel detection devices and systems such as the AX-positron emission tomography (PET) demonstrator often introduce or increase the measurement of atypical coincidence events such as inter-crystal scattering (ICS). In more standard systems, ICS events often go undetected and the small measured fraction may be ignored. As the measured quantity of such events in the data increases, so too does the importance of considering them during image reconstruction. Generally, treatment of ICS events will attempt to determine which of the possible candidate lines of response (LoRs) correctly determine the annihilation photon trajectory. However, methods of assessment often have low success rates or are computationally demanding. In this investigation alternative approaches are considered. Experimental data was taken using the AX-PET prototype and a NEMA phantom. Three methods of ICS treatment were assessed-each of which considered all possible candidate LoRs during image reconstruction. Maximum likelihood expectation maximization was used in conjunction with both standard (line-like) and novel (V-like in this investigation) detection responses modeled within the system matrix. The investigation assumed that no information other than interaction locations was available to distinguish between candidates, yet the methods assessed all provided means by which such information could be included. In all cases it was shown that the signal to noise ratio is increased using ICS events. However, only one method, which used full modeling of the ICS response in the system matrix-the V-like model-provided enhancement in all figures of merit assessed in this investigation. Finally, the optimal method of ICS incorporation was demonstrated using data from two small animals measured using the AX-PET demonstrator. |
| Address |
[Gillam, John E.; Solevi, Paola; Oliver, Josep F.; Rafecas, Magdalena] Univ Valencia, CSIC, IFIC, Valencia, Spain, Email: john.gillam@sydney.edu.au |
| 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 |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000340056800006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
|
| Call Number |
IFIC @ pastor @ |
Serial |
1879 |
| Permanent link to this record |
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| 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 |
|
Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000335785300016 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1790 |
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| Author |
Greynat, D.; Sesma, J.; Vulvert, G. |
| Title |
Derivatives of the Pochhammer and reciprocal Pochhammer symbols and their use in epsilon-expansions of Appell and Kampe de Feriet functions |
Type |
Journal Article |
| Year |
2014 |
Publication |
Journal of Mathematical Physics |
Abbreviated Journal |
J. Math. Phys. |
| Volume |
55 |
Issue |
4 |
Pages |
043501 - 16pp |
| Keywords |
|
| Abstract |
Useful expressions of the derivatives, to any order, of Pochhammer and reciprocal Pochhammer symbols with respect to their arguments are presented. They are building blocks of a procedure, recently suggested, for obtaining the e-expansion of functions of the hypergeometric class related to Feynman integrals. The procedure is applied to some examples of such kind of functions taken from the literature. |
| Address |
[Greynat, David] Ist Nazl Fis Nucl, Dipartimento Fis, Sez Napoli, I-80126 Naples, Italy, Email: david.greynat@gmail.com; |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Inst Physics |
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 |
0022-2488 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000336084100030 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1799 |
| Permanent link to this record |
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| |
| Author |
Taprogge, J. et al; Gadea, A.; Montaner-Piza, A. |
| Title |
Identification of a millisecond isomeric state in Cd-129(81) via the detection of internal conversion and Compton electrons |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
738 |
Issue |
|
Pages |
223-227 |
| Keywords |
Isomeric decays; Transition strengths; Shell model calculations |
| Abstract |
The decay of an isomeric state in the neutron-rich nucleus Cd-129 has been observed via the detection of internal conversion and Compton electrons providing first experimental information on excited states in this nucleus. The isomer was populated in the projectile fission of a U-238 beam at the Radioactive Isotope Beam Factory at RIKEN. From the measured yields of gamma-rays and internal conversion electrons, a multipolarity of E3 was tentatively assigned to the isomeric transition. A half-life of T-1/2 = 3.6(2) ms was determined for the new state which was assigned a spin of (21/2(+)), based on a comparison to shell model calculations performed using state-of-the-art realistic effective interactions. |
| Address |
[Taprogge, J.; Jungclaus, A.] CSIC, Inst Estruct Mat, Madrid 28006, Spain, Email: andrea.jungclaus@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 |
0370-2693 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000344624900036 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2021 |
| Permanent link to this record |
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| |
| Author |
AGATA Collaboration (Pellegri, L. et al); Gadea, A. |
| Title |
Pygmy dipole resonance in Sn-124 populated by inelastic scattering of O-17 |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
738 |
Issue |
|
Pages |
519-523 |
| Keywords |
Low-lying electric dipole excitations Sn-124; Isospin character |
| Abstract |
The gamma decay from the high-lying states of Sn-124 was measured using the inelastic scattering of O-17 at 340 MeV. The emitted gamma rays were detected with high resolution with the AGATA demonstrator array and the scattered ions were detected in two segmented Delta E-E silicon telescopes. The angular distribution was measured both for the gamma rays and the scattered O-17 ions. An accumulation of E1 strength below the particle threshold was found and compared with previous data obtained with (gamma,gamma') and (alpha,alpha'gamma) reactions. The present results of elastic scattering, and excitation of E2 and E1 states were analysed using the DWBA approach. From this comprehensive description the isoscalar component of the 1-excited states was extracted. The obtained values are based on the comparison of the data with DWBA calculations including a form factor deduced using a microscopic transition density. |
| Address |
[Pellegri, L.; Bracco, A.; Crespi, F. C. L.; Leoni, S.; Camera, F.; Avigo, R.; Benzoni, G.; Blasi, N. a; Boiano, C.; Bottoni, S.; Brambilla, S.; Ceruti, S.; Giaz, A.; Million, B.; Morales, A. I.; Nicolini, R.; Vandone, V.; Wieland, O.; Pullia, A.] INFN Sez Milano, I-20133 Milan, Italy, Email: angela.bracco@mi.infn.it |
| 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 |
0370-2693 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
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Conference |
|
| Notes |
WOS:000344624900078 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2024 |
| Permanent link to this record |
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| Author |
DELPHI Collaboration (Abdallah, J. et al); Costa, M.J.; Ferrer, A.; Fuster, J.; Garcia, C.; Oyanguren, A.; Perepelitsa, V.; Salt, J.; Tortosa, P. |
| Title |
Measurement of the electron structure function F-2(e) at LEP energies |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
737 |
Issue |
|
Pages |
39-47 |
| Keywords |
|
| Abstract |
The hadronic part of the electron structure function F-2(e) has been measured for the first time, using e(+)e(-) data collected by the DELPHI experiment at LEP, at centre-of-mass energies of root s = 91.2-209.5 GeV. The data analysis is simpler than that of the measurement of the photon structure function. The electron structure function F-2(e) data are compared to predictions of phenomenological models based on the photon structure function. It is shown that the contribution of large target photon virtualities is significant. The data presented can serve as a cross-check of the photon structure function F-2(gamma) analyses and help in refining existing parameterizations. |
| Address |
[Lamsa, J.] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA |
| 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 |
0370-2693 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000342757700008 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1965 |
| Permanent link to this record |
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| Author |
Valcarce, A.; Garcilazo, H.; Vijande, J. |
| Title |
Heavy baryon spectroscopy with relativistic kinematics |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
733 |
Issue |
|
Pages |
288-295 |
| Keywords |
|
| Abstract |
We present a comparative Faddeev study of heavy baryon spectroscopy with nonrelativistic and relativistic kinematics. We show results for different standard hyperfine interactions with both kinematics in an attempt to learn about the light quark dynamics. We highlight the properties of particular states accessible in nowadays laboratories that would help in discriminating between different dynamical models. The advance in the knowledge of light quark dynamics is a key tool for the understanding of the existence of exotic hadrons. |
| Address |
[Valcarce, A.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain |
| 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 |
0370-2693 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
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Conference |
|
| Notes |
WOS:000336430400050 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1806 |
| Permanent link to this record |
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| Author |
Scandale, W et al; Lari, L. |
| Title |
Deflection of high energy protons by multiple volume reflections in a modified multi-strip silicon deflector |
Type |
Journal Article |
| Year |
2014 |
Publication |
Nuclear Instruments & Methods in Physics Research B |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. B |
| Volume |
338 |
Issue |
|
Pages |
108-111 |
| Keywords |
Accelerator; Beam collimation; Crystal; Channeling; Volume reflection |
| Abstract |
The effect of multiple volume reflections in one crystal was observed in each of several bent silicon strips for 400 GeV/c protons. This considerably increased the particle deflections. Some particles were also deflected due to channeling in one of the subsequent strips. As a result, the incident beam was strongly spread because of opposite directions of the deflections. A modified multi-strip deflector produced by periodic grooves on the surface of a thick silicon plate was used for these measurements. This technique provides perfect mutual alignment between crystal strips. Such multi-strip deflector may be effective for collider beam halo collimation and a study is planned at the CERN SPS circulating beam. |
| Address |
[Scandale, W.; Arduini, G.; Butcher, M.; Cerutti, F.; Gilardoni, S.; Lari, L.; Lechner, A.; Losito, R.; Masi, A.; Mereghetti, A.; Metral, E.; Mirarchi, D.; Montesano, S.; Redaelli, S.; Schoofs, P.; Smirnov, G.] CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland |
| 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 |
0168-583x |
ISBN |
|
Medium |
|
| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000343390400016 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1974 |
| Permanent link to this record |
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| Author |
Brown, J.M.C.; Dimmock, M.R.; Gillam, J.E.; Paganin, D.M. |
| Title |
A low energy bound atomic electron Compton scattering model for Geant4 |
Type |
Journal Article |
| Year |
2014 |
Publication |
Nuclear Instruments & Methods in Physics Research B |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. B |
| Volume |
338 |
Issue |
|
Pages |
77-88 |
| Keywords |
Compton scattering; Geant4; Radiation transport modelling; Monte Carlo method |
| Abstract |
A two-body fully relativistic three-dimensional scattering framework has been utilised to develop an alternative Compton scattering computational model to those adapted from Ribberfors' work for Monte Carlo modelling of Compton scattering. Using a theoretical foundation that ensures the conservation of energy and momentum in the relativistic impulse approximation, this new model, the Monash University Compton scattering model, develops energy and directional algorithms for both the scattered photon and ejected Compton electron from first principles. The Monash University Compton scattering model was developed to address the limitation of the Compton electron directionality algorithms of other computational models adapted from Ribberfors' work. Here the development of the Monash University Compton scattering model, including its implementation in a Geant4 low energy electromagnetic physics class, G4LowEPComptonModel, is outlined. Assessment of the performance of G4LowEPComptonModel was undertaken in two steps: (1) comparison with respect to the two standard Compton scattering classes of Geant4 version 9.5, G4LivermoreComptonModel and G4PenelopeComptonModel, and (2) experimental comparison with respect to Compton electron kinetic energy spectra obtained from the Compton scattering of 662 key photons off the K-shell of gold. Both studies illustrate that the Monash University Compton scattering model, and in turn G4LowEPComptonModel, is a viable replacement for the majority of computational models that have been adapted from Ribberfors' work. It was also shown that the Monash University Compton scattering model is able to reproduce the Compton scattering triply differential cross-section Compton electron kinetic energy spectra of 662 keV photons K-shell scattering off of gold to within experimental uncertainty. |
| Address |
[Brown, J. M. C.; Paganin, D. M.] Monash Univ, Sch Phys, Clayton, Vic 3800, Australia, Email: jeremy.brown@cern.ch |
| 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 |
0168-583x |
ISBN |
|
Medium |
|
| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000343390400012 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1973 |
| Permanent link to this record |
