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Author Alvarez-Ruso, L.; Ledwig, T.; Martin Camalich, J.; Vicente Vacas, M.J.
Title Nucleon mass and pion-nucleon sigma term from a chiral analysis of lattice QCD data Type Journal Article
Year 2013 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 88 Issue 5 Pages 054507 - 20pp
Keywords
Abstract The pion mass dependence of the nucleon mass within the covariant SU(2) baryon chiral perturbation theory both without and with explicit Delta(1232) degrees of freedom up to order p(4) is investigated. By fitting to a comprehensive set of lattice QCD data in 2 and 2 + 1 flavors from several collaborations, for pion masses M-pi < 420 MeV, we obtain low energy constants of natural size that are compatible with pion-nucleon scattering data. Our results are consistent with the rather linear pion mass dependence showed by lattice QCD. In the 2 flavor case we have also performed simultaneous fits to nucleon mass and sigma(pi N) data. As a result of our analysis, which encompasses the study of finite volume corrections and discretization effects, we report a value of sigma(pi N) = 41(5)(4) MeV in the 2 flavor case and sigma(pi N) = 52(3)(8) MeV for 2 + 1 flavors, where the inclusion of the Delta(1232) resonance changes the results by around 9 MeV. In the 2 flavor case we are able to set independently the scale for lattice QCD data, given by a Sommer scale of r(0) = 0.493(23) fm.
Address [Alvarez-Ruso, L.] Univ Valencia, Ctr Mixto, CSIC, Inst Fis Corpuscular IFIC, E-46071 Valencia, Spain, Email: alvarez@ific.uv.es;
Corporate Author (up) Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000324636100005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1603
Permanent link to this record
 
 
Author Emmanuel-Costa, D.; Simoes, C.; Tortola, M.
Title The minimal adjoint-SU (5) x Z(4) GUT model Type Journal Article
Year 2013 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 054 - 30pp
Keywords Neutrino Physics; GUT; Discrete and Finite Symmetries
Abstract An extension of the adjoint SU (5) model with a flavour symmetry based on the Z(4) group is investigated. The Z(4) symmetry is introduced with the aim of leading the up-and down-quark mass matrices to the Nearest-Neighbour-Interaction form. As a consequence of the discrete symmetry embedded in the SU (5) gauge group, the charged lepton mass matrix also gets the same form. Within this model, light neutrinos get their masses through type-I, type-III and one-loop radiative seesaw mechanisms, implemented, respectively, via a singlet, a triplet and an octet from the adjoint fermionic 24 fields. It is demonstrated that the neutrino phenomenology forces the introduction of at least three 24 fermionic multiplets. The symmetry SU (5) x Z(4) allows only two viable zero textures for the effective neutrino mass matrix. It is showed that one texture is only compatible with normal hierarchy and the other with inverted hierarchy in the light neutrino mass spectrum. Finally, it is also demonstrated that Z(4) freezes out the possibility of proton decay through exchange of coloured Higgs triplets at tree-level.
Address [Emmanuel-Costa, D.; Simoes, C.] Univ Lisbon, Inst Super Tecn, Dept Fis, P-1049001 Lisbon, Portugal, Email: david.costa@ist.utl.pt;
Corporate Author (up) Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000325495200002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1604
Permanent link to this record
 
 
Author Watanabe, H. et al; Montaner-Piza, A.
Title Isomers in Pd-128 and Pd-126: Evidence for a Robust Shell Closure at the Neutron Magic Number 82 in Exotic Palladium Isotopes Type Journal Article
Year 2013 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 111 Issue 15 Pages 152501 - 5pp
Keywords
Abstract The level structures of the very neutron-rich nuclei Pd-128 and Pd-126 have been investigated for the first time. In the r-process waiting-point nucleus Pd-128, a new isomer with a half-life of 5.8(8) μs is proposed to have a spin and parity of 8(+) and is associated with a maximally aligned configuration arising from the g(9/2) proton subshell with seniority v = 2. For Pd-126, two new isomers have been identified with half-lives of 0.33(4) and 0.44(3) μs. The yrast 2(+) energy is much higher in Pd-128 than in Pd-126, while the level sequence below the 8(+) isomer in Pd-128 is similar to that in the N = 82 isotone Cd-130. The electric quadrupole transition that depopulates the 8(+) isomer in Pd-128 is more hindered than the corresponding transition in Cd-130, as expected in the seniority scheme for a semimagic, spherical nucleus. These experimental findings indicate that the shell closure at the neutron number N = 82 is fairly robust in the neutron-rich Pd isotopes.
Address [Watanabe, H.] Beihang Univ, Int Res Ctr Nuclei & Particles Cosmos, Beijing 100191, Peoples R China, Email: hiroshi@ribf.riken.jp
Corporate Author (up) Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000325372500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1605
Permanent link to this record
 
 
Author Dai, L.R.; Oset, E.
Title Tests on the molecular structure of f(2)(1270), f'(2) (1525) from psi(nS) and Upsilon(nS) decays Type Journal Article
Year 2013 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 49 Issue 10 Pages 130 - 6pp
Keywords
Abstract Based on previous studies that support the vector-vector molecular structure of the f(2)'(1270), f 2 (1525), K * 0 2 (1430), f0(1370) and f0(1710) resonances, we make predictions for the.(2S) decay into.(f) f2(1270),.(f) f 2 (1525), K* 0 (892) K * 0 2 (1430) and the radiative decay of.(1S),.(2S),.(2S) into.f2(1270),.f 2 (1525),.f0(1370),.f0(1710). Agreement with experimental data is found for three available ratios, without using free parameters, and predictions are done for other cases.
Address
Corporate Author (up) Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000325828600002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1607
Permanent link to this record
 
 
Author Mason, P.J.R. et al; Algora, A.
Title Half-life of the yrast 2(+) state in W-188: Evolution of deformation and collectivity in neutron-rich tungsten isotopes Type Journal Article
Year 2013 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 88 Issue 4 Pages 044301 - 6pp
Keywords
Abstract The half-life of the yrast I-pi = 2(+) state in the neutron-rich nucleus W-188 has been measured using fast-timing techniques with the HPGe and LaBr3:Ce array at the National Institute of Physics and Nuclear Engineering, Bucharest. The resulting value of t(1/2) = 0.87(12) ns is equivalent to a reduced transition probability of B(E2;2(1)(+) -> 0(1)(+)) = 85(12) W.u. for this transition. The B(E2;2(1)(+) -> 0(1)(+)) is compared to neighboring tungsten isotopes and nuclei in the Hf, Os, and Pt isotopic chains. Woods-Saxon potential energy surface (PES) calculations have been performed for nuclei in the tungsten isotopic chain and predict prolate deformed minima with rapidly increasing gamma softness for W184-192 and an oblate minimum for W-194.
Address [Mason, P. J. R.; Podolyak, Zs.; Regan, P. H.; Stevenson, P. D.; Alexander, T.; Alharbi, T.; Bowry, M.; Britton, R.; Bunce, M.; Gelletly, W.; Rice, S.; Townsley, C.; Wilson, E.; Wood, R. T.] Univ Surrey, Dept Phys, Guildford GU2 7XH, Surrey, England
Corporate Author (up) Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000325163700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1606
Permanent link to this record
 
 
Author ANTARES Collaboration (Adrian-Martinez, S. et al); Barrios-Marti, J.; Bigongiari, C.; Emanuele, U.; Gomez-Gonzalez, J.P.; Hernandez-Rey, J.J.; Lambard, G.; Mangano, S.; Sanchez-Losa, A.; Yepes, H.; Zornoza, J.D.; Zuñiga, J.
Title Measurement of the atmospheric nu (mu) energy spectrum from 100 GeV to 200 TeV with the ANTARES telescope Type Journal Article
Year 2013 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 73 Issue 10 Pages 2606 - 12pp
Keywords
Abstract Atmospheric neutrinos are produced during cascades initiated by the interaction of primary cosmic rays with air nuclei. In this paper, a measurement of the atmospheric energy spectrum in the energy range 0.1-200 TeV is presented, using data collected by the ANTARES underwater neutrino telescope from 2008 to 2011. Overall, the measured flux is similar to 25 % higher than predicted by the conventional neutrino flux, and compatible with the measurements reported in ice. The flux is compatible with a single power-law dependence with spectral index gamma (meas)=3.58 +/- 0.12. With the present statistics the contribution of prompt neutrinos cannot be established.
Address
Corporate Author (up) Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000325778600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1608
Permanent link to this record
 
 
Author Brown, J.M.C.; Gillam, J.E.; Paganin, D.M.; Dimmock, M.R.
Title Laplacian Erosion: An Image Deblurring Technique for Multi-Plane Gamma-Cameras Type Journal Article
Year 2013 Publication IEEE Transactions on Nuclear Science Abbreviated Journal IEEE Trans. Nucl. Sci.
Volume 60 Issue 5 Pages 3333-3342
Keywords
Abstract Laplacian Erosion, an image deblurring technique for multi-plane Gamma-cameras, has been developed and tested for planar imaging using a GEANT4 Monte Carlo model of the Pixelated Emission Detector for RadioisOtopes (PEDRO) as a test platform. A contrast and Derenzo-like phantom composed of I-125 were both employed to investigate the dependence of detection plane and pinhole geometry on the performance of Laplacian Erosion. Three different pinhole geometries were tested. It was found that, for the test system, the performance of Laplacian Erosion was inversely proportional to the detection plane offset, and directly proportional to the pinhole diameter. All tested pinhole geometries saw a reduction in the level of image blurring associated with the pinhole geometry. However, the reduction in image blurring came at the cost of signal to noise ratio in the image. The application of Laplacian Erosion was shown to reduce the level of image blurring associated with pinhole geometry and improve recovered image quality in multi-plane Gamma-cameras for the targeted radiotracer I-125.
Address
Corporate Author (up) Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0018-9499 ISBN Medium
Area Expedition Conference
Notes WOS:000325827200020 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1609
Permanent link to this record
 
 
Author Cabello, J.; Torres-Espallardo, I.; Gillam, J.E.; Rafecas, M.
Title PET Reconstruction From Truncated Projections Using Total-Variation Regularization for Hadron Therapy Monitoring Type Journal Article
Year 2013 Publication IEEE Transactions on Nuclear Science Abbreviated Journal IEEE Trans. Nucl. Sci.
Volume 60 Issue 5 Pages 3364-3372
Keywords
Abstract Hadron therapy exploits the properties of ion beams to treat tumors by maximizing the dose released to the target and sparing healthy tissue. With hadron beams, the dose distribution shows a relatively low entrance dose which rises sharply at the end of the range, providing the characteristic Bragg peak that drops quickly thereafter. It is of critical importance in order not to damage surrounding healthy tissues and/or avoid targeting underdosage to know where the delivered dose profile ends-the location of the Bragg peak. During hadron therapy, short-lived beta(+)-emitters are produced along the beam path, their distribution being correlated with the delivered dose. Following positron annihilation, two photons are emitted, which can be detected using a positron emission tomography (PET) scanner. The low yield of emitters, their short half-life, and the wash out from the target region make the use of PET, even only a few minutes after hadron irradiation, a challenging application. In-beam PET represents a potential candidate to estimate the distribution of beta(+)-emitters during or immediately after irradiation, at the cost of truncation effects and degraded image quality due to the partial rings required of the PET scanner. Time-of-flight (ToF) information can potentially be used to compensate for truncation effects and to enhance image contrast. However, the highly demanding timing performance required in ToF-PET makes this option costly. Alternatively, the use of maximum-a-posteriori-expectation-maximization (MAP-EM), including total variation (TV) in the cost function, produces images with low noise, while preserving spatial resolution. In this paper, we compare data reconstructed with maximum-likelihood-expectation-maximization (ML-EM) and MAP-EM using TV as prior, and the impact of including ToF information, from data acquired with a complete and a partial-ring PET scanner, of simulated hadron beams interacting with a polymethyl methacrylate (PMMA) target. The results show that MAP-EM, in the absence of ToF information, produces lower noise images and more similar data compared to the simulated beta(+) distributions than ML-EM with ToF information in the order of 200-600 ps. The investigation is extended to the combination of MAP-EM and ToF information to study the limit of performance using both approaches.
Address
Corporate Author (up) Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0018-9499 ISBN Medium
Area Expedition Conference
Notes WOS:000325827200023 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1610
Permanent link to this record
 
 
Author Oliver, J.F.; Fuster-Garcia, E.; Cabello, J.; Tortajada, S.; Rafecas, M.
Title Application of Artificial Neural Network for Reducing Random Coincidences in PET Type Journal Article
Year 2013 Publication IEEE Transactions on Nuclear Science Abbreviated Journal IEEE Trans. Nucl. Sci.
Volume 60 Issue 5 Pages 3399-3409
Keywords
Abstract Positron Emission Tomography (PET) is based on the detection in coincidence of the two photons created in a positron annihilation. In conventional PET, this coincidence identification is usually carried out through a coincidence electronic unit. An accidental coincidence occurs when two photons arising from different annihilations are classified as a coincidence. Accidental coincidences are one of the main sources of image degradation in PET. Some novel systems allow coincidences to be selected post-acquisition in software, or in real time through a digital coincidence engine in an FPGA. These approaches provide the user with extra flexibility in the sorting process and allow the application of alternative coincidence sorting procedures. In this work a novel sorting procedure based on Artificial Neural Network (ANN) techniques has been developed. It has been compared to a conventional coincidence sorting algorithm based on a time coincidence window. The data have been obtained from Monte-Carlo simulations. A small animal PET scanner has been implemented to this end. The efficiency (the ratio of correct identifications) can be selected for both methods. In one case by changing the actual value of the coincidence window used, and in the other by changing a threshold at the output of the neural network. At matched efficiencies, the ANN-based method always produces a sorted output with a smaller random fraction. In addition, two differential trends are found: the conventional method presents a maximum achievable efficiency, while the ANN-based method is able to increase the efficiency up to unity, the ideal value, at the cost of increasing the random fraction. Images reconstructed using ANN sorted data (no compensation for randoms) present better contrast, and those image features which are more affected by randoms are enhanced. For the image quality phantom used in the paper, the ANN method decreases the spill-over ratio by a factor of 18%.
Address
Corporate Author (up) Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0018-9499 ISBN Medium
Area Expedition Conference
Notes WOS:000325827200027 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1611
Permanent link to this record
 
 
Author Barrientos, D.; Gonzalez, V.; Bellato, M.; Gadea, A.; Bazzacco, D.; Blasco, J.M.; Bortolato, D.; Egea, F.J.; Isocrate, R.; Pullia, A.; Rampazzo, G.; Sanchis, E.; Triossi, A.
Title Multiple Register Synchronization With a High-Speed Serial Link Using the Aurora Protocol Type Journal Article
Year 2013 Publication IEEE Transactions on Nuclear Science Abbreviated Journal IEEE Trans. Nucl. Sci.
Volume 60 Issue 5 Pages 3521-3525
Keywords
Abstract In this work, the development and characterization of a multiple synchronous registers interface communicating with a high-speed serial link and using the Aurora protocol is presented. A detailed description of the developing process and the characterization methods and hardware test benches are also included. This interface will implement the slow control buses of the digitizer cards for the second generation of electronics for the Advanced GAmma Tracking Array (AGATA).
Address
Corporate Author (up) Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0018-9499 ISBN Medium
Area Expedition Conference
Notes WOS:000325827700014 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1612
Permanent link to this record