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Author Dorigo, T. et al; Ramos, A.; Ruiz de Austri, R.
Title Toward the end-to-end optimization of particle physics instruments with differentiable programming Type Journal Article
Year 2023 Publication (down) Reviews in Physics Abbreviated Journal Rev. Phys.
Volume 10 Issue Pages 100085 - pp
Keywords
Abstract The full optimization of the design and operation of instruments whose functioning relies on the interaction of radiation with matter is a super-human task, due to the large dimensionality of the space of possible choices for geometry, detection technology, materials, data-acquisition, and information-extraction techniques, and the interdependence of the related parameters. On the other hand, massive potential gains in performance over standard, “experience-driven” layouts are in principle within our reach if an objective function fully aligned with the final goals of the instrument is maximized through a systematic search of the configuration space. The stochastic nature of the involved quantum processes make the modeling of these systems an intractable problem from a classical statistics point of view, yet the construction of a fully differentiable pipeline and the use of deep learning techniques may allow the simultaneous optimization of all design parameters.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6096
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Author Gonzalez-Iglesias, D.; Gimeno, B.; Esperante, D.; Martinez-Reviriego, P.; Martin-Luna, P.; Fuster-Martinez, N.; Blanch, C.; Martinez, E.; Menendez, A.; Fuster, J.; Grudiev, A.
Title Non-resonant ultra-fast multipactor regime in dielectric-assist accelerating structures Type Journal Article
Year 2024 Publication (down) Results in Physics Abbreviated Journal Results Phys.
Volume 56 Issue Pages 107245 - 12pp
Keywords Multipactor; Dielectric accelerating structures; RF particle accelerators; Plasma discharge
Abstract The objective of this work is the evaluation of the risk of suffering a multipactor discharge in an S-band dielectric-assist accelerating (DAA) structure for a compact low-energy linear particle accelerator dedicated to hadrontherapy treatments. A DAA structure consists of ultra-low loss dielectric cylinders and disks with irises which are periodically arranged in a metallic enclosure, with the advantage of having an extremely high quality factor and very high shunt impedance at room temperature, and it is therefore proposed as a potential alternative to conventional disk-loaded copper structures. However, it has been observed that these structures suffer from multipactor discharges. In fact, multipactor is one of the main problems of these devices, as it limits the maximum accelerating gradient. Because of this, the analysis of multipactor risk in the early design steps of DAA cavities is crucial to ensure the correct performance of the device after fabrication. In this paper, we present a comprehensive and detailed study of multipactor in our DAA design through numerical simulations performed with an in-house developed code based on the Monte-Carlo method. The phenomenology of the multipactor (resonant electron trajectories, electron flight time between impacts, etc.) is described in detail for different values of the accelerating gradient. It has been found that in these structures an ultra-fast non-resonant multipactor appears, which is different from the types of multipactor theoretically studied in the scientific literature. In addition, the effect of several low electron emission coatings on the multipactor threshold is investigated. Furthermore, a novel design based on the modification of the DAA cell geometry for multipactor mitigation is introduced, which shows a significant increase in the accelerating gradient handling capabilities of our prototype.
Address [Gonzalez-Iglesias, Daniel; Gimeno, Benito; Esperante, Daniel; Martinez-Reviriego, Pablo; Martin-Luna, Pablo; Fuster-Martinez, Nuria; Blanch, Cesar; Martinez, Eduardo; Menendez, Abraham; Fuster, Juan] CSIC UV, Inst Fis Corpuscular IF, c Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: daniel.gonzalez-iglesias@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 2211-3797 ISBN Medium
Area Expedition Conference
Notes WOS:001133850600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5866
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Author Gisbert, H.; Pich, A.
Title Direct CP violation in K-0 -> pi pi : Standard Model Status Type Journal Article
Year 2018 Publication (down) Reports on Progress in Physics Abbreviated Journal Rep. Prog. Phys.
Volume 81 Issue 7 Pages 076201 - 22pp
Keywords Kaon decays; CP violation; Standard Model
Abstract In 1988 the NA31 experiment presented the first evidence of direct CP violation in the K-0 -> pi pi decay amplitudes. A clear signal with a 7.2 sigma statistical significance was later established with the full data samples from the NA31, E731, NA48 and KTeV experiments, confirming that CP violation is associated with a Delta S = 1 quark transition, as predicted by the Standard Model. However, the theoretical prediction for the measured ratio epsilon'/epsilon has been a subject of strong controversy along the years. Although the underlying physics was already clarified in 2001, the recent release of improved lattice data has revived again the theoretical debate. We review the current status, discussing in detail the different ingredients that enter into the calculation of this observable and the reasons why seemingly contradictory predictions were obtained in the past by several groups. An update of the Standard Model prediction is presented and the prospects for future improvements are analysed. Taking into account all known short-distance and long-distance contributions, one obtains Re (epsilon' / epsilon) = (15 +/- 7) . 10(-4), in good agreement with the experimental measurement.
Address [Gisbert, Hector; Pich, Antonio] Univ Valencia, CSIC, IFIC, Dept Fis Teor, Apt Correus 22085, E-46071 Valencia, Spain, Email: Antonio.Pich@ific.uv.es
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 0034-4885 ISBN Medium
Area Expedition Conference
Notes WOS:000436545600001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3641
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Author Curtin, D. et al; Hirsch, M.
Title Long-lived particles at the energy frontier: the MATHUSLA physics case Type Journal Article
Year 2019 Publication (down) Reports on Progress in Physics Abbreviated Journal Rep. Prog. Phys.
Volume 82 Issue 11 Pages 116201 - 133pp
Keywords Large Hadron Collider; long-lived particles; hierarchy problem; dark matter; baryogenesis; neutrinos; simplified models
Abstract We examine the theoretical motivations for long-lived particle (LLP) signals at the LHC in a comprehensive survey of standard model (SM) extensions. LLPs are a common prediction of a wide range of theories that address unsolved fundamental mysteries such as naturalness, dark matter, baryogenesis and neutrino masses, and represent a natural and generic possibility for physics beyond the SM (BSM). In most cases the LLP lifetime can be treated as a free parameter from the μm scale up to the Big Bang Nucleosynthesis limit of similar to 10(7) m. Neutral LLPs with lifetimes above similar to 100 m are particularly difficult to probe, as the sensitivity of the LHC main detectors is limited by challenging backgrounds, triggers, and small acceptances. MATHUSLA is a proposal for a minimally instrumented, large-volume surface detector near ATLAS or CMS. It would search for neutral LLPs produced in HL-LHC collisions by reconstructing displaced vertices (DVs) in a low-background environment, extending the sensitivity of the main detectors by orders of magnitude in the long-lifetime regime. We study the LLP physics opportunities afforded by a MATHUSLA-like detector at the HL-LHC, assuming backgrounds can be rejected as expected. We develop a model-independent approach to describe the sensitivity of MATHUSLA to BSM LLP signals, and compare it to DV and missing energy searches at ATLAS or CMS. We then explore the BSM motivations for LLPs in considerable detail, presenting a large number of new sensitivity studies. While our discussion is especially oriented towards the long-lifetime regime at MATHUSLA, this survey underlines the importance of a varied LLP search program at the LHC in general. By synthesizing these results into a general discussion of the top-down and bottom-up motivations for LLP searches, it is our aim to demonstrate the exceptional strength and breadth of the physics case for the construction of the MATHUSLA detector.
Address [Curtin, David] Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada, Email: dcurtin@physics.utoronto.ca
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 0034-4885 ISBN Medium
Area Expedition Conference
Notes WOS:000499698000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4215
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Author Kasieczka, G. et al; Sanz, V.
Title The LHC Olympics 2020: a community challenge for anomaly detection in high energy physics Type Journal Article
Year 2021 Publication (down) Reports on Progress in Physics Abbreviated Journal Rep. Prog. Phys.
Volume 84 Issue 12 Pages 124201 - 64pp
Keywords anomaly detection; machine learning; unsupervised learning; weakly supervised learning; semisupervised learning; beyond the standard model; model-agnostic methods
Abstract A new paradigm for data-driven, model-agnostic new physics searches at colliders is emerging, and aims to leverage recent breakthroughs in anomaly detection and machine learning. In order to develop and benchmark new anomaly detection methods within this framework, it is essential to have standard datasets. To this end, we have created the LHC Olympics 2020, a community challenge accompanied by a set of simulated collider events. Participants in these Olympics have developed their methods using an R&D dataset and then tested them on black boxes: datasets with an unknown anomaly (or not). Methods made use of modern machine learning tools and were based on unsupervised learning (autoencoders, generative adversarial networks, normalizing flows), weakly supervised learning, and semi-supervised learning. This paper will review the LHC Olympics 2020 challenge, including an overview of the competition, a description of methods deployed in the competition, lessons learned from the experience, and implications for data analyses with future datasets as well as future colliders.
Address [Kasieczka, Gregor] Univ Hamburg, Inst Expt Phys, Hamburg, Germany, Email: gregor.kasieczka@uni-hamburg.de;
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 0034-4885 ISBN Medium
Area Expedition Conference
Notes WOS:000727698500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5039
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Author Borsato, M. et al; Zurita, J.; Henry, L.; Jashal, B.K.; Oyanguren, A.
Title Unleashing the full power of LHCb to probe stealth new physics Type Journal Article
Year 2022 Publication (down) Reports on Progress in Physics Abbreviated Journal Rep. Prog. Phys.
Volume 85 Issue 2 Pages 024201 - 45pp
Keywords LHCb; stealth physics; BSM physics; hidden sectors; long-lived particles; dark matter
Abstract In this paper, we describe the potential of the LHCb experiment to detect stealth physics. This refers to dynamics beyond the standard model that would elude searches that focus on energetic objects or precision measurements of known processes. Stealth signatures include long-lived particles and light resonances that are produced very rarely or together with overwhelming backgrounds. We will discuss why LHCb is equipped to discover this kind of physics at the Large Hadron Collider and provide examples of well-motivated theoretical models that can be probed with great detail at the experiment.
Address [Borsato, M.] Heidelberg Univ, Phys Inst, Heidelberg, Germany, Email: xabier.cid.vidal@cern.ch
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 0034-4885 ISBN Medium
Area Expedition Conference
Notes WOS:000762056700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5151
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Author AbdusSalam, S.S. et al; Eberhardt, O.
Title Simple and statistically sound recommendations for analysing physical theories Type Journal Article
Year 2022 Publication (down) Reports on Progress in Physics Abbreviated Journal Rep. Prog. Phys.
Volume 85 Issue 5 Pages 052201 - 11pp
Keywords particle physics; statistics; methodology
Abstract Physical theories that depend on many parameters or are tested against data from many different experiments pose unique challenges to statistical inference. Many models in particle physics, astrophysics and cosmology fall into one or both of these categories. These issues are often sidestepped with statistically unsound ad hoc methods, involving intersection of parameter intervals estimated by multiple experiments, and random or grid sampling of model parameters. Whilst these methods are easy to apply, they exhibit pathologies even in low-dimensional parameter spaces, and quickly become problematic to use and interpret in higher dimensions. In this article we give clear guidance for going beyond these procedures, suggesting where possible simple methods for performing statistically sound inference, and recommendations of readily-available software tools and standards that can assist in doing so. Our aim is to provide any physicists lacking comprehensive statistical training with recommendations for reaching correct scientific conclusions, with only a modest increase in analysis burden. Our examples can be reproduced with the code publicly available at Zenodo.
Address [AbdusSalam, Shehu S.; Fowlie, Andrew] Shahid Beheshti Univ, Dept Phys, Tehran, Iran, Email: andrew.j.fowlie@njnu.edu.cn
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 0034-4885 ISBN Medium
Area Expedition Conference
Notes WOS:000791574900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5221
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Author Perez-Calatayud, J.; Ballester, F.; Tedgren, C.; DeWerd, L.A.; Papagiannis, P.; Rivard, M.J.; Siebert, F.A.; Vijande, J.
Title GEC-ESTRO ACROP recommendations on calibration and traceability of HE HDR-PDR photon-emitting brachytherapy sources at the hospital level Type Journal Article
Year 2022 Publication (down) Radiotherapy and Oncology Abbreviated Journal Radiother. Oncol.
Volume 176 Issue Pages 108-117
Keywords Brachytherapy; High energy; Calibration; Dosimetry; HDR-PDR
Abstract The vast majority of radiotherapy departments in Europe using brachytherapy (BT) perform temporary implants of high-or pulsed-dose rate (HDR-PDR) sources with photon energies higher than 50 keV. Such techniques are successfully applied to diverse pathologies and clinical scenarios. These recommen-dations are the result of Working Package 21 (WP-21) initiated within the BRAchytherapy PHYsics Quality Assurance System (BRAPHYQS) GEC-ESTRO working group with a focus on HDR-PDR source cal-ibration. They provide guidance on the calibration of such sources, including practical aspects and issues not specifically accounted for in well-accepted societal recommendations, complementing the BRAPHYQS WP-18 Report dedicated to low energy BT photon emitting sources (seeds). The aim of this report is to provide a European-wide standard in HDR-PDR BT source calibration at the hospital level to maintain high quality patient treatments.
Address [Perez-Calatayud, Jose] La Fe Hosp, Radiotherapy Dept, Valencia, Spain, Email: javier.vijande@uv.es
Corporate Author Thesis
Publisher Elsevier Ireland Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0167-8140 ISBN Medium
Area Expedition Conference
Notes WOS:000880438000006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5466
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Author Viegas, R.; Roser, J.; Barrientos, L.; Borja-Lloret, M.; Casaña, J.V.; Lopez, J.G.; Jimenez-Ramos, M.C.; Hueso-Gonzalez, F.; Ros, A.; Llosa, G.
Title Characterization of a Compton camera based on the TOFPET2 ASIC Type Journal Article
Year 2023 Publication (down) Radiation Physics and Chemistry Abbreviated Journal Radiat. Phys. Chem.
Volume 202 Issue Pages 110507 - 11pp
Keywords Compton camera; Hadron therapy; LaBr3; PETsys TOFPET2; Silicon photomultipliers
Abstract The use of Compton cameras for medical imaging and its interest as a hadron therapy treatment monitoring has increased in the last decade with the development of silicon photomultipliers. MACACOp is a Compton camera prototype designed and assembled at the IRIS group of IFIC-Valencia. This Compton camera is based on monolithic Lanthanum (III) Bromide crystals and silicon photomultipliers, and employs the novel TOFPET2 ASIC as readout electronics. This system emerged as an alternative to MACACO II prototype, with the aim of improving its limited time resolution. To test the performance of the ASIC in a Compton camera setup, the prototype was characterized, both in laboratory and in-beam. A time resolution of 1.5 ns was obtained after time corrections, which improves greatly the performance of the MACACO II. Moreover, the results obtained at high photon energies demonstrate the ability of the system to obtain 1 mm displacements of the reconstructed spots. The results reinforce the potential of the system as a monitoring device for hadron therapy.
Address [Viegas, R.; Roser, J.; Barrientos, L.; Borja-Lloret, M.; Casana, J., V; Hueso-Gonzalez, F.; Ros, A.; Llosa, G.] CSIC UV, Inst Fis Corpuscular IFIC, Valencia, Spain, Email: Rita.Viegas@ific.uv.es
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0969-806x ISBN Medium
Area Expedition Conference
Notes WOS:000870840600006 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5392
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Author Barrientos, L.; Borja-Lloret, M.; Casana, J.V.; Hueso-Gonzalez, F.; Ros, A.; Roser, J.; Senra, C.; Solaz, C.; Viegas, R.; Llosa, G.
Title System characterization and performance studies with MACACO III Compton camera Type Journal Article
Year 2023 Publication (down) Radiation Physics and Chemistry Abbreviated Journal Radiat. Phys. Chem.
Volume 208 Issue Pages 110922 - 13pp
Keywords Compton camera; Scintillator crystals; Silicon photomultipliers
Abstract The IRIS group of IFIC-Valencia has developed a Compton camera prototype. The system detectors are made of Lanthanum (III) bromide scintillator crystals coupled to silicon photomultipliers. Two models of silicon photomultipliers arrays with different micro pixel pitch (25 and 50 μm) have been chosen as possible candidates to improve the response of the new system. Characterization studies with a 22Na point-like source have indicated that the 25 μm photodetector provided better performance in terms of energy resolution (5.2% FWHM at 511 keV) and angular resolution (6.9 degrees FWHM at 1275 keV), and more stability with temperature variations. In addition, MACACO III imaging capabilities have been assessed using a structure composed of thirty-seven 22Na point-like sources. Furthermore, in order to evaluate possible ways of improving the system performance, several studies have been carried out by means of simulations both in realistic and performance improved conditions. In this work, the system performance is evaluated for its future application in different areas.
Address [Barrientos, L.; Borja-Lloret, M.; Casana, J. V.; Hueso-Gonzalez, F.; Ros, A.; Roser, J.; Senra, C.; Solaz, C.; Viegas, R.; Llosa, G.] CSIC UV, Inst Fis Corpuscular IF, Valencia, Spain, Email: Luis.Barrientos@ific.uv.es;
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0969-806x ISBN Medium
Area Expedition Conference
Notes WOS:000962800400001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5511
Permanent link to this record