Track Trigger Research Articles

53 - Comparative Study of Artificial Intelligence Triggering Technique and Conventional Bolus Tracking Triggering Technique in Coronary CT Angiography

53 - Comparative Study of Artificial Intelligence Triggering Technique and Conventional Bolus Tracking Triggering Technique in Coronary CT Angiography

Performance of the ATLAS L1 Transition Radiation Tracker Trigger in Heavy-ion Collisions at the LHC

Performance of the ATLAS L1 Transition Radiation Tracker Trigger in Heavy-ion Collisions at the LHC

Intel Stratix 10 FPGA design for track reconstruction for the ATLAS experiment at the HL-LHC

The fast reconstruction of charged particle tracks with high efficiency and track quality is an essential part of the online data selection for the ATLAS experiment at the High Luminosity LHC.Dedicated custom designed hardware boards and software simulations have been developed to assess the feasibility of a Hardware Tracking Trigger (HTT) system.The Pattern Recognition Mezzanine (PRM), as part of the HTT system, has been designed to recognize track candidates in silicon detectors with Associative Memory ASICs and to select and reconstruct tracks using linearized algorithms implemented in an Intel Stratix 10 MX FPGA.The highly parallelized FPGA design makes extensive use of the integrated High-Bandwidth-Memory.In this paper, the FPGA design for the PRM board is presented. Its functionalities have been verified in both simulations and hardware tests on an Intel Stratix 10 MX development kit.

Operation of the Neural z-Vertex Track Trigger for Belle II in 2021 - a Hardware Perspective

To reduce the background the z-Vertex Track Trigger estimates the collision origin in the Belle II experiment using neural networks. The main part is a pre-trained multilayer perceptron. The task of this perceptron is to estimate the z-vertex of the collision to suppress background from outside the interaction point. For this, a low latency real-time FPGA implementation is needed. We present an overview of the architecture and the FPGA implementation of the neuronal network and the preprocessing. We also show the handling of missing input data through preprocessing with specially trained neuronal networks implemented in hardware. For this, we will show the results of the z-vertex estimation and the latency for the implementation in the Belle II trigger system. Major update for the preprocessing stage utilizing a 3D Hough transformation processing step is ongoing.

A digital approach to asthma self-management in adults: Protocol for a pragmatic randomized controlled trial

Asthma self-management can improve symptom control, but adherence to established self-management behaviors is often poor. With adult asthma uncontrolled in over 60% of U.S. cases, there is a need for scalable, cost-effective tools to improve asthma outcomes. Here we describe a protocol for the Asthma Digital Study, a 24-month, decentralized, pragmatic, open-label, randomized controlled trial investigating the impact of a digital asthma self-management (DASM) program on asthma outcomes in adults. The program leverages consumer-grade devices with a smartphone app to provide “smart nudges,” symptom logging, trigger tracking, and other features. Participants are recruited (target N = 900) from throughout the U.S., and randomized to a DASM or control arm (1:1). Co-primary outcomes at one year are a) asthma-associated costs for acute care and b) change from baseline in Asthma Control Test™ scores. Findings may inform decisions around adoption of digital tools for asthma self-management.Trial registration:clinicaltrials.gov identifier: NCT04609644. Registered: Oct 30, 2020.

Two-particle Bose–Einstein correlations in { pp } collisions at mathbf {sqrt{s} = 13} TeV measured with the ATLAS detector at the LHC

This paper presents studies of Bose–Einstein correlations (BEC) in proton–proton collisions at a centre-of-mass energy of 13 TeV, using data from the ATLAS detector at the CERN Large Hadron Collider. Data were collected in a special low-luminosity configuration with a minimum-bias trigger and a high-multiplicity track trigger, accumulating integrated luminosities of 151 upmu b^{-1} and 8.4 nb^{-1}, respectively. The BEC are measured for pairs of like-sign charged particles, each with |eta | < 2.5, for two kinematic ranges: the first with particle p_{mathrm {T}} > 100 MeV and the second with particle p_{mathrm {T}} > 500 MeV. The BEC parameters, characterizing the source radius and particle correlation strength, are investigated as functions of charged-particle multiplicity (up to 300) and average transverse momentum of the pair (up to 1.5 GeV). The double-differential dependence on charged-particle multiplicity and average transverse momentum of the pair is also studied. The BEC radius is found to be independent of the charged-particle multiplicity for high charged-particle multiplicity (above 100), confirming a previous observation at lower energy. This saturation occurs independent of the transverse momentum of the pair.

Probing naturally light singlets with a displaced vertex trigger

We investigate the physics case for a dedicated trigger on a low mass, hadronic displaced vertex at the high luminosity LHC, relying on the CMS phase II track trigger. We estimate the trigger efficiency with a simplified simulation of the CMS track trigger and show that the L1 trigger rate from fake vertices, B meson decays and secondary interactions with the detector material can likely be brought down to the kHz level with a minimal set of cuts. While it would with any doubt be a severe experimental challenge to implement, we conclude that a displaced vertex trigger could open qualitatively new parameter space for exotic Higgs decays, exotic B decays and even direct production of light resonances. We parametrize the physics potential in terms of a singlet scalar mixing with the Standard Model Higgs and an axion-like particle with a coupling to gluons, and review a number or relevant models motivated by the hierarchy and strong CP problems, Dark Matter and baryogenesis.

Searching for exotic B -meson decays enabled by the CMS L1 track trigger

The CMS phase II track trigger may allow for a displaced dimuon vertex trigger with qualitatively lower $p_T$ thresholds than existing dimuon triggers. With this technique, we show that the CMS reach for exotic $B$-meson decays involving a displaced dimuon resonance, such as a light, Higgs-mixed scalar, can be competitive with that of LHCb and Belle II.

Tracking Triggers for the HL-LHC

Hardware-based track reconstruction in the CMS and ATLAS trigger systems for the high-luminosity upgrade of the LHC (HL-LHC) will provide unique capabilities. In this review, we present an overview of earlier track trigger systems at hadron colliders, in particular those at the Tevatron CDF and DØ experiments. We discuss the plans of the CMS and ATLAS experiments to implement hardware-based track reconstruction for the HL-LHC. Particular focus is placed on the track trigger capability of the upgraded CMS experiment. We discuss the challenges and opportunities of this novel capability, review the alternatives that were considered for its implementation, and discuss its expected performance. The planned track trigger systems for CMS and ATLAS have different goals, and we compare and contrast the two approaches.

Development of the Level-1 track trigger with Central Drift Chamber detector in Belle II experiment and its performance in SuperKEKB 2019 Phase 3 operation

The Level-1 trigger system (TRG) in the Belle II experiment is designed to summarize real-time sub-detectors information by using FPGA chips for the central data acquisition (DAQ) system, and it includes several sub-trigger systems for triggering various types of physics events in interest. The main focus in this report is CDCTRG: the track trigger system with Central Drift Chamber (CDC) detector, which is responsible for the real-time trajectory reconstruction of charged particles with various algorithms: Track-Segment Finder, 2D, 3D, Neuro-3D, and short tracking. CDCTRG is necessary for specific types of physics, such as hadronic and μ pair. This paper will introduce the design of the hardware system and algorithm implementation in FPGAs. Development, validation and performance of each CDCTRG module during SuperKEKB beam collision operation will also be discussed in detail.

A 3D track finder for the Belle II CDC L1 trigger

Machine learning methods are integrated into the pipelined first level (L1) track trigger of the upgraded flavor physics experiment Belle II at KEK in Tsukuba, Japan. The novel triggering techniques cope with the severe background from events outside the small collision region provided by the new SuperKEKB asymmetric-energy electron-positron collider. Using the precise drift-time information of the central drift chamber which provides axial and stereo wire layers, a neural network L1 trigger estimates the 3D track parameters of tracks, based on input from the axial wire planes provided by a 2D track finder. An extension of this 2D Hough track finder to a 3D finder is proposed, where the single hit representations in the Hough plane are trained using Monte Carlo. This 3D finder improves the track finding efficiency by including the stereo sense wires as input. The estimated polar track angle allows a specialization of the subsequent neural networks to sectors in the polar angle.

Tracking triggering mechanisms for soft-sediment deformation structures in the Late Cretaceous Uberaba Formation, Bauru Basin, Brazil

Abstract Soft-sediment deformation (SSD) structures are widespread in the sedimentary record, and numerous triggering mechanisms can induce its development, including glaciation, earthquakes, overloading, ground-water fluctuations, and wave movement. The Late Cretaceous Uberaba Formation preserves SSD structures as small- and large-scale load casts and associated flame structures, pseudonodules, and convolute laminations observed in the contact of three well-defined intervals among fine- to coarse-grained lithic and conglomeratic sandstone with fine-grained arkose and mudstone beds. Based on the morphology of the SSD structures, sedimentary facies of the Uberaba Formation, and similarities with previous observations in the geological record and laboratory models, these features are assigned to liquefaction-fluidization processes as the major deformational mechanism triggered by seismic and aseismic agents. We propose that a deformation occurred just after the sedimentation triggered by seismic shock waves and overloading, induced by the sudden deposition of coarse-grained sandy debris on fine-grained sediments. Some of these structures can be classified as seismites, providing evidence of intraplate seismicity within the inner part of the South American Platform during the Late Cretaceous. This seismic activity is likely related to the uplift of the Alto Paranaiba High along reactivations of regional structures inherited from Proterozoic crustal discontinuities and coeval explosive magmatism of the Minas-Goias Alkaline Province.

National Association for Gun Rights, Inc. v. Mangan et al. - Amicus Brief for the U.S. Supreme Court

At issue in National Association for Gun Rights, Inc. v. Mangan, No. 19-767 (U.S..), was whether government may trigger Track 1, political-committee(-like) burdens for a particular organization. Attached is a copyrighted draft — dated June 2, 2020 — of the amicus brief that the author would have filed with the parties' consent — as indicated on page 1, footnote 4 — if the Supreme Court had not denied certiorari on June 1, 2020. The Supreme Court has applied constitutional scrutiny and established the two-track system under which government may regulate—i.e., require disclosure of—political speech. E.g., Buckley v. Valeo, 424 U.S. 1, 63-64, 79-82 (1976) (per curiam); Randy Elf, The Constitutionality of State Law Triggering Burdens on Political Speech and the Current Circuit Splits, 29 Regent U.L. Rev. 35, 35-37 & nn.1-12 (2016) (“Triggering”). This action does not address Track 2, non-political-committee disclosure requirements. Instead, this action addresses law triggering Track 1, political-committee(-like) burdens. The Ninth Circuit has a different two-track system for state law. Triggering at 54 & n.109. However, the Ninth Circuit should have conformed its law to Supreme Court case law, under which government may trigger Track 1 burdens only for “organizations” that are “under the control of” candidates in their capacities as candidates, or for “organizations” having “the major purpose” under Buckley, 424 U.S. at 79; Triggering at 48 & n.84, and engaging in more than small-scale speech, Sampson v. Buescher, 625 F.3d 1247, 1249, 1251, 1261 (10th Cir. 2010); Triggering at 62-64 & nn.153-54. Moreover, “the appeal-to-vote test—once known as the ‘functional equivalent of express advocacy’—no longer affects whether government may ban, otherwise limit, or regulate speech, and the appeal-to-vote test is vague. It has no place in law.” Triggering at 77.

To catch a long-lived particle: hit selection towards a regional hardware track trigger implementation

Conventional searches for new phenomena at collider experiments tend to focus on prompt particles, produced at the interaction point and decaying rapidly. New physics models including long-lived particles that travel a substantial distance in the detectors before decaying provide an interesting alternative, especially in light of the lack of new phenomena at the current LHC experiments, and could solve unanswered questions of the Standard Model. Long-lived particles have characteristic experimental signatures that, while making them clearly distinct from other processes, also could make them potentially invisible to current data-acquisition methods. Specific trigger strategies need to be in place to target long-lived particles. In this paper, we investigate the use of tracker information at trigger level to identify displaced signatures. We propose two methods that can be implemented at hardware-level: one based on the Hough transform, and another based on pattern matching with patterns trained on displaced tracks.

Performance Study of the First 2-D Prototype of Vertically Integrated Pattern Recognition Associative Memory

Extremely fast pattern recognition capabilities are necessary to find and fit billions of tracks at the hardware trigger level produced every second anticipated at high-luminosity Large Hadron Collider (HL-LHC) running conditions. Associative memory (AM)-based approaches for fast pattern recognition have been proposed as a potential solution to the tracking trigger. However, at the HL-LHC, there is much less time available, and the speed performance must be improved over previous systems while maintaining a comparable number of patterns. The vertically integrated pattern recognition AM (VIPRAM) project aims to achieve the target pattern density and performance goal using 3DIC technology. The first step taken in the VIPRAM work was the development of a 2-D prototype ( protoVIPRAM00 ) in which the AM building blocks were designed to be compatible with the 3-D integration. In this article, we present the results from extensive performance studies of the protoVIPRAM00 chip in both realistic HL-LHC and extreme conditions. Results indicate that the chip operates at the design frequency of 100 MHz with perfect correctness in realistic conditions and conclude that the building blocks are ready for 3-D stacking. We also present performance boundary characterization of the chip under extreme conditions.

First-level muon track trigger for future hadron collider experiments

Abstract Single muon triggers are crucial for the physics programmes as hadron collider experiments. To be sensitive to electroweak processes, single muon triggers with transverse momentum thresholds down to 20 GeV and dimuon triggers with even lower thresholds are required. In order to keep the rates of these triggers at an acceptable level these triggers have to be highly selective, i.e. they must have small accidental trigger rates and sharp trigger turn-on curves. The muon systems of the LHC experiments and experiments at future colliders like FCC-hh will use two muon chamber systems for the muon trigger, fast trigger chambers like RPCs with coarse spatial resolution and much slower precision chambers like drift–tube chambers with high spatial resolution. The data of the trigger chambers are used to identify the bunch crossing in which the muon was created and for a rough momentum measurement while the precise measurements of the muon trajectory by the precision chambers are ideal for an accurate muon momentum measurement. A concept for the muon trigger of the baseline detector for the FCC-hh which exploits the precision measurements of drift–tube chambers is presented including the description and the test of a compact muon track reconstruction algorithm.

Hardware demonstrator of a compact first-level muon track trigger for future hadron collider experiments

Single muon triggers are crucial for the physics programmes at hadron collider experiments. To be sensitive to electroweak processes, single muon triggers with transverse momentum thresholds down to 20 GeV and dimuon triggers with even lower thresholds are required. In order to keep the rates of these triggers at an acceptable level these triggers have to be highly selective, i.e. they must have small accidental trigger rates and sharp trigger turn-on curves. The muon systems of the LHC experiments and experiments at future colliders like FCC-hh will use two muon chamber systems for the muon trigger, fast trigger chambers like RPCs with coarse spatial resolution and much slower precision chambers like drift-tube chambers with high spatial resolution. The data of the trigger chambers are used to identify the bunch crossing in which the muon was created and for a rough momentum measurement while the precise measurements of the muon trajectory by the precision chambers are ideal for an accurate muon momentum measurement. A compact muon track finding algorithm is presented, where muon track candidates are reconstructed using a binning algorithm based on a 1D Hough Transform. The algorithm has been designed and implemented on a System-On-Chip device. A hardware demonstration using Xilinx Evaluation boards ZC706 has been set-up to prove the concept. The system has demonstrated the feasibility to reconstruct muon tracks with a good angular resolution, whilst satisfying latency constraints. The demonstrated track-reconstruction system, the chosen architecture, the achievements to date and future options for such a system will be discussed.

Search for Highly Ionizing Particles with the Pixel Detector at Belle II

The Belle II experiment, located at the SuperKEKB collider at the high-energy research facility KEK in Tsukuba, Japan, started operation in 2018. Compared to the predecessor experiment Belle, Belle II plans to increase the peak luminosity by a factor of about 40, by employing nano-beam technology in the interaction region. In particular the new, innermost sub-detector of Belle II the Pixel Vertex Detector (PXD) - is in close proximity to the interaction point. This allows for the detection of particles, which do not leave a signal in the outer sub-detectors. Among these, Highly Ionizing Particles (HIPs) encounter a characteristically high energy loss, limiting their penetration depth into the detector. Anti-deuterons and magnetic monopoles as possible HIPs are considered. Without a signal in the outer sub-detectors, no track trigger is issued, resulting in possible information loss. The possibility of identifying HIPs solely with information provided by the PXD is presented, by using neural network algorithms operating in a multidimensional parameter space of PXD cluster data.

Citizens for Responsibility and Ethics in Washington et al. v. FEC (New Models) - Amicus Brief for the D.C. Circuit

At issue in Citizens for Responsibility and Ethics in Washington et al. v. FEC, No. 19-5161 (D.C. Cir.), is whether government may trigger Track 1, political-committee(-like) burdens for a particular organization. Attached is a copyrighted amicus brief that the author filed with the parties' consent, as indicated on page 1, footnote 5. The Supreme Court has applied constitutional scrutiny and established the two-track system under which government may regulate—i.e., require disclosure of—political speech. E.g., Buckley v. Valeo, 424 U.S. 1, 63-64, 79-82 (1976) (per curiam); Randy Elf, The Constitutionality of State Law Triggering Burdens on Political Speech and the Current Circuit Splits, 29 Regent U.L. Rev. 35, 35-37 & nn.1-12 (2016) (“Triggering”). This action does not address Track 2, non-political-committee disclosure requirements. Instead, this action addresses law triggering Track 1, political-committee(-like) burdens. Government may trigger such burdens only for “organizations” that are “under the control of” candidates in their capacities as candidates, or for “organizations” having “the major purpose” under Buckley, 424 U.S. at 79; Triggering at 48 & n.84, and engaging in more than small-scale speech, Sampson v. Buescher, 625 F.3d 1247, 1249, 1251, 1261 (10th Cir. 2010); Triggering at 62-64 & nn.153-54. One method of determining the Buckley major purpose asks whether an organization devotes the majority of its spending to contributions to, or independent expenditures for, candidates or ballot measures, Triggering at 60-61 & nn.147-50, with “independent expenditure” meaning Buckley express advocacy that is not coordinated with a candidate, id. at 36 n.9, 61 n.150, 67 & nn.168-71. No constitutional method of determining the Buckley major purpose includes contributions other than contributions to candidates or ballot measures, or independent spending other than independent expenditures properly understood. Id. at 60-61 & nn.147-50. This excludes contributions to others. This also excludes the appeal-to-vote test. Id. at 60 n.148, 70 & n.184. Indeed, “the appeal-to-vote test—once known as the ‘functional equivalent of express advocacy’—no longer affects whether government may ban, otherwise limit, or regulate speech, and the appeal-to-vote test is vague. It has no place in law.” Id. at 77. The last page of the attached copyrighted brief is a newspaper column by the author. It summarizes Triggering and is cited in Triggering at 85 n.278.

Characterisation of the MONDO detector response to neutrons by means of a FLUKA Monte Carlo simulation

Particle therapy is increasingly used for the treatment of solid tumours, especially when the tolerance of organs at risk for conventional radiotherapy becomes dose limiting. To take full advantage of the particle therapy potential, the beam range in tissues has to be precisely known and the secondary particles production during the treatment has to be accurately characterised, as it can lead to unwanted dose deposition far from the target volume. Secondary neutrons can release a remarkable dose, also far from the tumour, increasing the probability of secondary cancer late insurgence in the patient. Currently, the treatment planning system software used in clinical routine suffer from the lack of high precision data related to the secondary neutron production in particle therapy treatments.The aim of the MONDO (MOnitor for Neutron Dose in hadrOntherapy) project is to develop a tracking detector for secondary neutrons in the energy range of 20−400 MeV. Neutrons flux, energy spectra and angular distribution will become experimentally available by tracking the recoil protons produced after two consecutive neutron elastic scattering interactions in a 10×10×20cm3 matrix of scintillating fibres.A Monte Carlo simulation based on the FLUKA code was developed to optimise the MONDO detector layout, define the tracker trigger logic, evaluate the background contamination and possible strategies for its reduction: preliminary results are reported in this manuscript.A 4×4×4.8cm3 detector prototype was tested with protons at the APSS Proton Therapy Centre in Trento (Italy), where calibration and efficiency measurements were performed. Experimental and simulated results were compared.