Punzi, G., Baldini, W., Bassi, G., Contu, A., Fantechi, R., He, J. B., et al. (2024). Detector-embedded reconstruction of complex primitives using FPGAs. Nucl. Instrum. Methods Phys. Res. A, 1069, 169782–4pp.
Abstract: The slowdown of Moore's law and the growing requirements of future HEP experiments with ever-increasing data rates pose important computational challenges for data reconstruction and trigger systems, encouraging the exploration of new computing methodologies. In this work we discuss a FPGA-based tracking system, relying on a massively parallel pattern recognition approach, inspired by the processing of visual images by the natural brain (“retina architecture”). This method allows a large efficiency of utilisation of the hardware, low power consumption and very low latencies. Based on this approach, a device has been designed within the LHCb Upgrade-II project, with the goal of performing track reconstruction in the forward acceptance region in real-time during the upcoming Run 4 of the LHC. This innovative device will perform track reconstruction before the event-building, in a short enough time to provide pre-reconstructed tracks (“primitives”) transparently to the processor farm, as if they had been generated directly by the detector. This allows significant savings in higher-level computing resources, enabling handling higher luminosities than otherwise possible. The feasibility of the project is backed up by the results of tests performed on a realistic hardware prototype, that has been opportunistically processing actual LHCb data in parallel with the regular DAQ in the LHC Run 3.
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Belle-II DEPFET and PXD Collaborations(Ahlburg, P. et al), & Marinas, C. (2024). The new and complete Belle II DEPFET pixel detector: Commissioning and previous operational experience. Nucl. Instrum. Methods Phys. Res. A, 1068, 169763–6pp.
Abstract: The Belle II experiment at the SuperKEKB collider in Tsukuba, Japan, has collected e+e- + e – collision data between 2019 and 2022. After reaching a record-breaking instantaneous luminosity of 4.71x1034 . 71x10 34 cm -2 s -1 and recording a dataset corresponding to 424 fb -1 , it completed its first planned long shutdown phase in December 2023. Aside from upgrades of the collider and detector maintenance, the shutdown was used for the installation of the two-layer Pixel VerteX Detector (PXD). As the innermost sub-detector, multiple scattering effects need to be reduced. PXD utilizes the Depleted P-channel Field Effect Transistor (DEPFET) technology, allowing for a material budget of 0.21% X0 0 per layer. Each of the tracker's 40 modules consists of an array of 250x768 pixels with a pitch ranging from 50 μmx 55 μm for the inner to 85 μmx 55 μm for the outer layer yielding high gain and high signal-to-noise ratio while retaining about 99% hit efficiency. This article discusses the experience of the 4-year operation of the previous single-layer PXD in harsh background conditions as well as commissioning and testing of the fully-populated PXD2 during Long Shutdown 1.
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Babeluk, M. et al, Lacasta, C., Marinas, C., Mazorra de Cos, J., & Vobbilisetti, V. (2024). The OBELIX chip for the Belle II VTX upgrade. Nucl. Instrum. Methods Phys. Res. A, 1067, 169659–3pp.
Abstract: The OBELIX depleted monolithic active CMOS pixel sensor (DMAPS) is currently developed for the upgrade of the vertex detector of the Belle II experiment located at Tsukuba/Japan. The pixel matrix of OBELIX is inherited from the TJ-Monopix2 chip, but the periphery includes additional features to improve performance and allow the integration into a larger detector system. The new features include a trigger unit to process trigger signals, a precision timing module and a possibility to transmit low granularity hit information with low latency to contribute to the Belle II trigger. Additionally, low dropout voltage regulators and an ADC to monitor power consumption and substrate temperature is developed. This paper will focus on the trigger contribution capabilities of the OBELIX chip.
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Miyagawa, P. S. et al, Bernabeu, P., Lacasta, C., Solaz, C., & Soldevila, U. (2024). Analysis of the results from Quality Control tests performed on ATLAS18 Strip Sensors during on-going production. Nucl. Instrum. Methods Phys. Res. A, 1064, 169457–9pp.
Abstract: The ATLAS experiment will replace its existing Inner Detector with the new all -silicon Inner Tracker (ITk) to cope with the operating conditions of the forthcoming high -luminosity phase of the LHC (HL-LHC). The outer regions of the ITk will be instrumented with similar to 18000 ATLAS18 strip sensors fabricated by Hamamatsu Photonics K.K. (HPK). With the launch of full-scale sensor production in 2021, the ITk strip sensor community has undertaken quality control (QC) testing of these sensors to ensure compliance with mechanical and electrical specifications agreed with HPK. The testing is conducted at seven QC sites on each of the monthly deliveries of similar to 500 sensors. This contribution will give an overview of the QC procedures and analysis; the tests most likely to determine pass/fail for a sensor are IV, long-term leakage current stability, full strip test and visual inspection. The contribution will then present trends in the results and properties following completion of similar to 60% of production testing. It will also mention challenges overcome through collaborative efforts with HPK during the early phases of production. With less than 5% of sensors rejected by QC testing, the overall production quality has been very good.
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Bach, E. et al, Bernabeu, J., Lacasta, C., Solaz, C., & Soldevila, U. (2024). Analysis of the quality assurance results from the initial part of production of the ATLAS18 ITK strip sensors. Nucl. Instrum. Methods Phys. Res. A, 1064, 169435–8pp.
Abstract: The production of strip sensors for the ATLAS Inner Tracker (ITk) started in 2021. Since then, a Quality Assurance (QA) program has been carried out continuously, by using specific test structures, in parallel to the Quality Control (QC) inspection of the sensors. The QA program consists of monitoring sensor-specific characteristics and the technological process variability, before and after the irradiation with gammas, neutrons, and protons. After two years, half of the full production volume has been reached and we present an analysis of the parameters measured as part of the QA process. The main devices used for QA purposes are miniature strip sensors, monitor diodes, and the ATLAS test chip, which contains several test structures. Such devices are tested by several sites across the collaboration depending on the type of samples (non-irradiated components or irradiated with protons, neutrons, or gammas). The parameters extracted from the tests are then uploaded to a database and analyzed by Python scripts. These parameters are mainly examined through histograms and timeevolution plots to obtain parameter distributions, production trends, and meaningful parameter-to-parameter correlations. The purpose of this analysis is to identify possible deviations in the fabrication or the sensor quality, changes in the behavior of the test equipment at different test sites, or possible variability in the irradiation processes. The conclusions extracted from the QA program have allowed test optimization, establishment of control limits for the parameters, and a better understanding of device properties and fabrication trends. In addition, any abnormal results prompt immediate feedback to a vendor.
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Escrig, S. et al, Bernabeu, J., Lacasta, C., & Solaz, C. (2024). First test of energy response of the micro-vertex detection system for the WASA-FRS Experiments. Nucl. Instrum. Methods Phys. Res. A, 1064, 169392–4pp.
Abstract: The hypernuclei, which are nuclei that contain the quark s, have been studied for more than 50 years. Notwithstanding, the recent experiments using high-energy heavy-ion induced reactions have challenged their current understanding. The high multiplicity of particles generated in the reaction allows for the measurement of the interaction point of the primary beam with the target. Then, a micro-vertex detection system for the WASA-FRS Experiments has been developed. Several experimental tests have been performed with Sr-90 and Bi-207 beta sources and a 10-MeV proton beam at the CMAM tandem accelerator, and their results are reported.
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Belle II VTX Collaboration(Babeluk, M. et al)., Marinas, C., & Mazorra de Cos, J. (2024). The DMAPS upgrade of the Belle II vertex detector. Nucl. Instrum. Methods Phys. Res. A, 1064, 169428–5pp.
Abstract: The Belle II experiment at KEK in Japan considers an upgrade for the vertex detector system in line with the accelerator upgrade for higher luminosity at long shutdown 2 planned for 2028. One proposal for the upgrade of the vertex detector called VTX aims to improve background robustness and reduce occupancy using small and fast pixels. VTX accommodates the OBELIX depleted monolithic active CMOS pixel sensor (DMAPS) on all five proposed layers. OBELIX is specifically developed for the VTX application and based on the TJ-Monopix2 chip initially developed to meet the requirements of the outer layers of the ATLAS inner tracker (ITk). This paper will review recent tests of the TJ-Monopix2 chip as well as various design aspects of the OBELIX-1 chip currently under development.
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Nascimento, J. R., Olmo, G. J., Petrov, A. Y., & Porfirio, P. J. (2024). On metric-affine bumblebee model coupled to scalar matter. Nucl. Phys. B, 1004, 116577–10pp.
Abstract: We consider the coupling of the metric-affine bumblebee gravity model to scalar matter and calculate the lower -order contributions to two -point functions of bumblebee and scalar fields in the weak gravity approximation. We also obtain the one -loop effective potentials for both scalar and vector fields.
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ANTARES Collaboration(Albert, A. et al), Alves, S., Calvo, D., Carretero, V., Gozzini, R., Hernandez-Rey, J. J., et al. (2024). Searches for Neutrinos in the Direction of Radio-bright Blazars with the ANTARES Telescope. Astrophys. J., 964(1), 3–13pp.
Abstract: Active galaxies, especially blazars, are among the most promising extragalactic candidates for high-energy neutrino sources. To date, ANTARES searches included these objects and used GeV-TeV gamma-ray flux to select blazars. Here, a statistically complete blazar sample selected by their bright radio emission is used as the target for searches of origins of neutrinos collected by the ANTARES neutrino telescope over 13 yr of operation. The hypothesis of a neutrino-blazar directional correlation is tested by pair counting and a complementary likelihood-based approach. The resulting posttrial p-value is 3.0% (2.2 sigma in the two-sided convention). Additionally, a time-dependent analysis is performed to search for temporal clustering of neutrino candidates as a means of detecting neutrino flares in blazars. None of the investigated sources alone reaches a significant flare detection level. However, the presence of 18 sources with a pretrial significance above 3 sigma indicates a p = 1.4% (2.5 sigma in the two-sided convention) detection of a time-variable neutrino flux. An a posteriori investigation reveals an intriguing temporal coincidence of neutrino, radio, and gamma-ray flares of the J0242+1101 blazar at a p = 0.5% (2.9 sigma in the two-sided convention) level. Altogether, the results presented here suggest a possible connection of neutrino candidates detected by the ANTARES telescope with radio-bright blazars.
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HAWC Collaboration(Alfaro, R. et al), & Salesa Greus, F. (2024). Galactic Gamma-Ray Diffuse Emission at TeV Energies with HAWC Data. Astrophys. J., 961(1), 104–14pp.
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.
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