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Author Bombacigno, F.; Boudet, S.; Montani, G.
Title Generalized Ashtekar variables for Palatini f(R) models Type Journal Article
Year 2021 Publication Nuclear Physics B Abbreviated Journal Nucl. Phys. B
Volume (down) 963 Issue Pages 115281 - 21pp
Keywords
Abstract We consider special classes of Palatini f(R) theories, featured by additional Loop Quantum Gravity inspired terms, with the aim of identifying a set of modified Ashtekar canonical variables, which still preserve the SU(2) gauge structure of the standard theory. In particular, we allow for affine connection to be endowed with torsion, which turns out to depend on the additional scalar degree affecting Palatini f( R) gravity, and in this respect we successfully construct a novel Gauss constraint. We analyze the role of the additional scalar field, outlining as it acquires a dynamical character by virtue of a non vanishing Immirzi parameter, and we describe some possible effects on the area operator stemming from such a revised theoretical framework. Finally, we compare our results with earlier studies in literature, discussing differences between metric and Palatini approaches. It is worth noting how the Hamiltonian turns out to be different in the two cases. The results can be reconciled when the analysis is performed in the Einstein frame.
Address [Bombacigno, Flavio] Univ Valencia, CSIC, Ctr Mixto, Dept Fis Teor, Valencia 46100, Spain, Email: flavio.bombacigno@ext.uv.es;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0550-3213 ISBN Medium
Area Expedition Conference
Notes WOS:000613579500003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4706
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Author HAWC Collaboration (Alfaro, R. et al); Salesa Greus, F.
Title Galactic Gamma-Ray Diffuse Emission at TeV Energies with HAWC Data Type Journal Article
Year 2024 Publication Astrophysical Journal Abbreviated Journal Astrophys. J.
Volume (down) 961 Issue 1 Pages 104 - 14pp
Keywords
Abstract Galactic gamma-ray diffuse emission (GDE) is emitted by cosmic rays (CRs), ultra-relativistic protons, and electrons, interacting with gas and electromagnetic radiation fields in the interstellar medium. Here we present the analysis of teraelectronvolt diffuse emission from a region of the Galactic plane over the range in longitude of l is an element of[43 degrees, 73 degrees], using data collected with the High Altitude Water Cherenkov (HAWC) detector. Spectral, longitudinal, and latitudinal distributions of the teraelectronvolt diffuse emission are shown. The radiation spectrum is compatible with the spectrum of the emission arising from a CR population with an index similar to that of the observed CRs. When comparing with the DRAGON base model, the HAWC GDE flux is higher by about a factor of 2. Unresolved sources such as pulsar wind nebulae and teraelectronvolt halos could explain the excess emission. Finally, deviations of the Galactic CR flux from the locally measured CR flux may additionally explain the difference between the predicted and measured diffuse fluxes.
Address [Alfaro, R.; Rojas, D. Avila; Belmont-Moreno, E.; Espinoza, C.; Hernandez, S.; Leon Vargas, H.; Sandoval, A.; Serna-Franco, J.] Univ Nacl Autonoma Mexico, Inst Fis, Ciudad De Mexico, Mexico, Email: amid.nayerhoda@ifj.edu.pl
Corporate Author Thesis
Publisher IOP Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-637x ISBN Medium
Area Expedition Conference
Notes WOS:001188034600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6022
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Author Schreeck, H.; Paschen, B.; Wieduwilt, P.; Ahlburg, P.; Andricek, L.; Dingfelder, J.; Frey, A.; Lutticke, F.; Marinas, C.; Richter, R.; Schwenker, B.
Title Effects of gamma irradiation on DEPFET pixel sensors for the Belle II experiment Type Journal Article
Year 2020 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 959 Issue Pages 163522 - 9pp
Keywords DEPFET; Radiation damage; Particle tracking detectors; Belle II
Abstract For the Belle II experiment at KEK (Tsukuba, Japan) the KEKB accelerator was upgraded to deliver a 40 times larger instantaneous luminosity than before, which requires an increased radiation hardness of the detector components. As the innermost part of the Belle II detector, the pixel detector (PXD), based on DEPFET (DEpleted P-channel Field Effect Transistor) technology, is most exposed to radiation from the accelerator. An irradiation campaign was performed to verify that the PXD can cope with the expected amount of radiation. We present the results of this measurement campaign in which an X-ray machine was used to irradiate a single PXD half-ladder to a total dose of 266 kGy. The half-ladder is from the same batch as the half-ladders used for Belle II. According to simulations, the total accumulated dose corresponds to 7-10 years of Belle II operation. While individual components have been irradiated before, this campaign is the first full system irradiation. We discuss the effects on the DEPFET sensors, as well as the performance of the front-end electronics. In addition, we present efficiency studies of the half-ladder from beam tests performed before and after the irradiation.
Address [Schreeck, Harrison; Wieduwilt, Philipp; Frey, Ariane; Schwenker, Benjamin] Georg August Univ Gottingen, Phys Inst 2, Friedrich Hund Pl 1, D-37077 Gottingen, Germany, Email: harrison.schreeck@phys.uni-goettingen.de
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000518368800016 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4316
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Author Ljungvall, J.; Perez-Vidal, R.M.; Lopez-Martens, A.; Michelagnoli, C.; Clement, E.; Dudouet, J.; Gadea, A.; Hess, H.; Korichi, A.; Labiche, M.; Lalovic, N.; Li, H.J.; Recchia, F.
Title Performance of the Advanced GAmma Tracking Array at GANIL Type Journal Article
Year 2020 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 955 Issue Pages 163297 - 13pp
Keywords AGATA spectrometer; GANIL facility; gamma-ray tracking; Nuclear structure; HPGe detectors
Abstract The performance of the Advanced GAmma Tracking Array (AGATA) at GANIL is discussed, on the basis of the analysis of source and in-beam data taken with up to 30 segmented crystals. Data processing is described in detail. The performance of individual detectors are shown. The efficiency of the individual detectors as well as the efficiency after gamma-ray tracking are discussed. Recent developments of gamma-ray tracking are also presented. The experimentally achieved peak-to-total is compared with simulations showing the impact of back-scattered gamma rays on the peak-to-total in a gamma-ray tracking array. An estimate of the achieved position resolution using the Doppler broadening of in-beam data is also given. Angular correlations from source measurements are shown together with different methods to take into account the effects of gamma-ray tracking on the normalization of the angular correlations.
Address [Ljungvall, J.; Lopez-Martens, A.; Dudouet, J.; Korichi, A.] Univ Paris Saclay, Univ Paris Sud, CNRS IN2P3, CSNSM, F-91405 Orsay, France, Email: joa.ljungvall@csnsm.in2p3.fr
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000508940400029 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4276
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Author Babiano, V.; Balibrea, J.; Caballero, L.; Calvo, D.; Ladarescu, I.; Mira Prats, S.; Domingo-Pardo, C.
Title First i-TED demonstrator: A Compton imager with Dynamic Electronic Collimation Type Journal Article
Year 2020 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume (down) 953 Issue Pages 163228 - 9pp
Keywords Compton imaging; Position-sensitive detectors; Monolithic crystals; Silicon photomultiplier
Abstract i-TED consists of both a total energy detector and a Compton camera primarily intended for the measurement of neutron capture cross sections by means of the simultaneous combination of neutron time-of-flight (TOF) and gamma-ray imaging techniques. TOF allows one to obtain a neutron-energy differential capture yield, whereas the imaging capability is intended for the discrimination of radiative background sources, that have a spatial origin different from that of the capture sample under investigation. A distinctive feature of i-TED is the embedded Dynamic Electronic Collimation (DEC) concept, which allows for a trade-off between efficiency and image resolution. Here we report on some general design considerations and first performance characterization measurements made with an i-TED demonstrator in order to explore its gamma-ray detection and imaging capabilities.
Address [Babiano, V; Balibrea, J.; Caballero, L.; Calvo, D.; Ladarescu, I; Mira Prats, S.; Domingo-Pardo, C.] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: domingo@ific.uv.es
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000506419900045 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4250
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