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Author |
Abdullahi, A.M. et al; Lopez-Pavon, J. |
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Title |
The present and future status of heavy neutral leptons |
Type |
Journal Article |
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Year |
2023 |
Publication |
Journal of Physics G |
Abbreviated Journal |
J. Phys. G |
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Volume |
50 |
Issue |
2 |
Pages  |
020501 - 100pp |
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Keywords |
Neutrinos; beyond the standard model; sterile neutrinos |
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Abstract |
The existence of nonzero neutrino masses points to the likely existence of multiple Standard Model neutral fermions. When such states are heavy enough that they cannot be produced in oscillations, they are referred to as heavy neutral leptons (HNLs). In this white paper, we discuss the present experimental status of HNLs including colliders, beta decay, accelerators, as well as astrophysical and cosmological impacts. We discuss the importance of continuing to search for HNLs, and its potential impact on our understanding of key fundamental questions, and additionally we outline the future prospects for next-generation future experiments or upcoming accelerator run scenarios. |
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Address |
[Abdullahi, Asli M.; Plestid, Ryan] Fermilab Natl Accelerator Lab, Theoret Phys Dept, POB 500, Batavia, IL 60510 USA, Email: shoemaker@vt.edu |
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Publisher |
IOP Publishing Ltd |
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Language |
English |
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ISSN |
0954-3899 |
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Conference |
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Notes |
WOS:000918351600001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5486 |
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Author |
Albiol, F.; Corbi, A.; Albiol, A. |
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Title |
Densitometric Radiographic Imaging With Contour Sensors |
Type |
Journal Article |
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Year |
2019 |
Publication |
IEEE Access |
Abbreviated Journal |
IEEE Access |
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Volume |
7 |
Issue |
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Pages |
18902-18914 |
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Keywords |
Conventional X-ray imaging; contour data; densitometric images; dynamic range; depth information |
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Abstract |
We present the technical/physical foundations of a new imaging technique that combines ordinary radiographic information (generated by conventional X-ray settings) with the patient's volume to derive densitometric images. Traditionally, these images provide quantitative information about tissues densities. In our approach, they graphically enhance either soft or bony regions. After measuring the patient's volume with contour recognition devices, the physical traversed lengths within it (as the Roentgen beam intersects the patient) are calculated and pixel-wise associated with the original radiograph (X). In order to derive this map of lengths (L), the camera equations of the X-ray system and the contour sensor are determined. The patient's surface is also translated to the point-of-view of the X-ray beam and all its entrance/exit points are sought with the help of ray-casting methods. The derived L is applied to X as a physical operation (subtraction), obtaining soft tissue-(D-S) or bone-enhanced (D'(B)) figures. In the D-S type, the contained graphical information can be linearly mapped to the average electronic density (traversed by the X-ray beam). This feature represents an interesting proof-of-concept of associating density data to radiographs, but most important, their intensity histogram is objectively compressed, i.e., the dynamic range is more shrunk (compared against the corresponding X). This leads to other advantages: improvement in the visibility of border/edge areas (high gradient), extended manual window level/width manipulations during screening, and immediate correction of underexposed X instances. In the D-B' type, high-density elements are highlighted and easier to discern. All these results can be achieved with low-energy beam exposures, saving costs and dose. Future work will deepen this clinical side of our research. In contrast with other image-based modifiers, the proposed method is grounded on the measurement of a physical entity: the span of the X-ray beam within a body while undertaking a radiographic examination. |
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Address |
[Albiol, Francisco; Corbi, Alberto] CSIC, Inst Fis Corpuscular, Paterna 46980, Spain, Email: kiko@ific.uv.es |
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Publisher |
Ieee-Inst Electrical Electronics Engineers Inc |
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Language |
English |
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Edition |
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ISSN |
2169-3536 |
ISBN |
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Expedition |
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Conference |
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Notes |
WOS:000459591800001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
3920 |
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Author |
Coves, A.; Maestre, H.; Archiles, R.; Andres, M.V.; Gimeno, B. |
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Title |
Surface-Impedance Formulation for Hollow-Core Waveguides Based on Subwavelength Gratings |
Type |
Journal Article |
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Year |
2022 |
Publication |
IEEE Access |
Abbreviated Journal |
IEEE Access |
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Volume |
10 |
Issue |
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Pages |
18843-18854 |
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Keywords |
Electromagnetic waveguides; Optical waveguides; Planar waveguides; Gratings; Surface waves; Surface impedance; Optical surface waves; Surface impedance; hollow-core waveguide; surface-relief grating |
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Abstract |
A rigorous Surface Impedance (SI) formulation for planar waveguides is presented. This modal technique splits the modal analysis of the waveguide in two steps. First, we obtain the modes characteristic equations as a function of the SI and, second, we need to obtain the surface impedance values using either analytical or numerical methods. We validate the technique by comparison with well-known analytical cases: the parallel-plate waveguide with losses and the dielectric slab waveguide. Then, we analyze an optical hollow-core waveguide defined by two high-contrast subwavelength gratings validating our results by comparison with reported values. Finally, we show the potential of our formulation with the analysis of a THz hollow-core waveguide defined by two surface-relief subwavelength gratings, including material losses in our formulation. |
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Address |
[Coves, Angela; Maestre, Haroldo] Univ Miguel Hernandez Elche, Dept Commun Engn I3E, Elche 03202, Spain, Email: angela.coves@umh.es |
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Publisher |
Ieee-Inst Electrical Electronics Engineers Inc |
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Language |
English |
Summary Language |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2169-3536 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000760714900001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
5139 |
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Author |
KM3NeT Collaboration (Aiello, S. et al); Alves Garre, S.; Calvo, D.; Carretero, V.; Colomer, M.; Corredoira, I; Gozzini, S.R.; Hernandez-Rey, J.J.; Khan Chowdhury, N.R.; Manczak, J.; Muñoz Perez, D.; Palacios Gonzalez, J.; Pieterse, C.; Real, D.; Salesa Greus, F.; Thakore, T.; Zornoza, J.D.; Zuñiga, J. |
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Title |
Architecture and performance of the KM3NeT front-end firmware |
Type |
Journal Article |
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Year |
2021 |
Publication |
Journal of Astronomical Telescopes, Instruments and Systems |
Abbreviated Journal |
J. Astron. Telesc. Instrum. Syst. |
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Volume |
7 |
Issue |
1 |
Pages |
016001 - 24pp |
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Keywords |
neutrino telescope; acquisition firmware; time to digital converters; KM3NeT |
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Abstract |
The KM3NeT infrastructure consists of two deep-sea neutrino telescopes being deployed in the Mediterranean Sea. The telescopes will detect extraterrestrial and atmospheric neutrinos by means of the incident photons induced by the passage of relativistic charged particles through the seawater as a consequence of a neutrino interaction. The telescopes are configured in a three-dimensional grid of digital optical modules, each hosting 31 photomultipliers. The photomultiplier signals produced by the incident Cherenkov photons are converted into digital information consisting of the integrated pulse duration and the time at which it surpasses a chosen threshold. The digitization is done by means of time to digital converters (TDCs) embedded in the field programmable gate array of the central logic board. Subsequently, a state machine formats the acquired data for its transmission to shore. We present the architecture and performance of the front-end firmware consisting of the TDCs and the state machine. |
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Address |
[Aiello, Sebastiano; Leonora, Emanuele; Longhitano, Fabio; Randazzo, Nunzio] Ist Nazl Fis Nucl, Sez Catania, Catania, Italy, Email: dacaldia@ific.uv.es; |
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Thesis |
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Publisher |
Spie-Soc Photo-Optical Instrumentation Engineers |
Place of Publication |
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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 |
2329-4124 |
ISBN |
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Conference |
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Notes |
WOS:000636679100031 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4784 |
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| Permanent link to this record |
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Author |
Arrechea, J.; Delhom, A.; Jimenez-Cano, A. |
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Title |
Inconsistencies in four-dimensional Einstein-Gauss-Bonnet gravity |
Type |
Journal Article |
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Year |
2021 |
Publication |
Chinese Physics C |
Abbreviated Journal |
Chin. Phys. C |
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Volume |
45 |
Issue |
1 |
Pages |
013107 - 8pp |
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Keywords |
alternative theories of gravity; singularities; Einstein-Gauss-Bonnet |
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Abstract |
We attempt to clarify several aspects concerning the recently presented four-dimensional Einstein-Gauss-Bonnet gravity. We argue that the limiting procedure outlined in [Phys. Rev. Lett. 124, 081301 (2020)] generally involves ill-defined terms in the four dimensional field equations. Potential ways to circumvent this issue are discussed, alongside remarks regarding specific solutions of the theory. We prove that, although linear perturbations are well behaved around maximally symmetric backgrounds, the equations for second-order perturbations are ill-defined even around a Minkowskian background. Additionally, we perform a detailed analysis of the spherically symmetric solutions and find that the central curvature singularity can be reached within a finite proper time. |
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Address |
[Arrechea, Julio] CSIC, Inst Astrofis Andalucia, Granada, Spain, Email: arrechea@iaa.es; |
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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 |
1674-1137 |
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:000606026400001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
4676 |
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| Permanent link to this record |
