The upgraded CMS Pixel Tracker Detector installed during the 2016-2017 extended year-end technical stop consists of four layers in the barrel region and three disks on both sides in the forward region. This made it possible to perform a real fit on quadruplet of hits selected by a Cellular Automaton algorithm to form the pixel tracks. Pixel tracks are an important component of the CMS...
Particle physicists at the Large Hadron Collider (LHC) investigate the properties of matter at length scales one million times smaller than the atom by colliding together high-energy protons 40 million times per second and observing the decay products of the collisions. ATLAS is one of two general-purpose detectors that reconstruct the interactions and as part of a wide range of physics goals...
Track finding with GPGPU-implemented fourth order Runge-Kutta (RK) method is investigated to track electrons from muon decay in the COMET Phase-I drift chamber. The COMET Phase-I experiment is aiming for discovering the neutrinoless, coherent transition of a muon to an electron in the field of an aluminium nucleus, $\mu^-N \rightarrow e^-N$, with a single event sensitivity of $3\times10^{-15}$...
One of the major components of the Belle II trigger system is the neural network trigger. Its task is to estimate the z-Vertex particle tracks observed in the experiments drift chamber. The trigger is implemented on FPGAs to ensure flexibility during operation and leverage their IO capabilities. Meanwhile the implementation has to estimate the vertex in a few hundred nanoseconds to fulfill the...
In the High Luminosity LHC, planned to start with Run4 in 2026, the ATLAS experiment will be equipped with the Hardware Track Trigger (HTT) system, a dedicated hardware system able to reconstruct tracks in the silicon detectors with short latency. This HTT will be composed of about 700 ATCA boards, based on new technologies available on the market, like high speed links and powerful FPGAs, as...
The growing exploration of machine learning algorithms in particle physics offers new solutions to simulation, reconstruction, and analysis. These new machine learning solutions often lead to increased parallelization and faster reconstructions times on dedicated hardware, here specifically Field Programmable Gate Arrays (FPGAs). We explore the possibility that applications of machine learning...
The RD53 Collaboration was established in 2013 to develop the next generation of pixel readout chips for the High Luminosity LHC detector upgrades. This proposal is to extend the scope of the collaboration to design the final pixel readout chip for the ATLAS and CMS upgrade detectors. A common design is proposed that can be fabricated with different pixel matrix sizes. The proposed work plan...
For the HL-LHC, the CMS and ATLAS collaborations have defined the detector geometry of their respective timing layers. Even though both collaborations have selected UFSD in their baseline design, the requirements for the two experiments differ in key aspects such as with pixel size, radiation hardness, number of layers. In this contribution we review the requirements and challenges in the...
It is foreseen to significantly increase the luminosity of the LHC by upgrading towards the HL- LHC (High Luminosity LHC) in order to harvest the maximum physics potential. Especially the Phase-II-Upgrade foreseen for 2023 will mean unprecedented radiation levels, significantly beyond the limits of the silicon trackers currently employed. All-silicon central trackers are being studied in...
The LHC machine is planning an upgrade program, which will smoothly bring the luminosity at about $5-7.5x10^{34}~\mathrm{cm}^{-2}\mathrm{s}^{-1}$ in 2028, to possibly reach an integrated luminosity of 3000-4500 fb$^{-1}$ by the end of 2039. This High-Luminosity LHC scenario, HL-LHC, will require a preparation program of the LHC detectors known as Phase-2 upgrade. The current CMS Outer Tracker,...
The LHCb Collaboration is planning an Upgrade II, a flavour physics experiment for the
high luminosity LHC era. This will be installed in LS4 (2030) and targets an instantaneous luminosity of 1 to $2 \times 10^{34$} cm$^{-2}$ s$^{-1}$ so as to collect an integrated luminosity of at least 300fb^{-1}. Modest
consolidation of the current experiment will also be introduced in LS3 (2025).
The...
For the Belle II experiment at the SuperKEKB asymmetric electron-positron collider (KEK, Japan) the concept of a first level track trigger, realized by neural networks, is presented. Using the input from a traditional Hough-based 2D track finder, the stereo wire layers of the Belle II Central Drift Chamber are used to reconstruct by neural methods the origin of the tracks along the beam ("z")...
Tracking in high-density environments, such as the core of TeV jets, is particularly challenging both because combinatorics quickly diverge and because tracks may not leave anymore individual "hits" but rather large clusters of merged signals in the innermost tracking detectors. In the CMS collaboration, this problem has been addressed in the past with cluster splitting algorithms, working...
In the transition to Run 3 in 2021, LHCb will undergo a major luminosity upgrade, going from 1.1 to 5.6 expected visible Primary Vertices (PVs) per event, and will adopt a purely software trigger. This has fueled increased interest in alternative highly-parallel and GPU friendly algorithms for tracking and reconstruction. We will present a novel prototype algorithm for vertexing in the LHCb...
With the upgrade of the LHC to high luminosity, an increased rate of collisions will place a higher computational burden on track reconstruction algorithms. Typical algorithms such as the Kalman Filter and Hough-like Transformation scale worse than quadratically. However, the energy function of a traditional method for tracking, the geometric Denby-Peterson (Hopfield) network method, can be...
D-Wave Systems Quantum Annealer (QA) finds the ground state of a Hamiltonian expressed as:
$$ O(a;b;q)= \sum_{i=1}^{N} a_i q_i +\sum_i^{N} \sum_{j < i}^{N} b_{ij} q_i q_j $$
This Quantum Machine Instruction (QMI) is equivalent to a Quadratic Unconstrained Binary Optimization (QUBO) and can be transformed easily into an Ising model or a Hopfield network.
Following Stimpfl-Abele[1], we...
To address the unprecedented scale of HL-LHC data, the HEP.TrkX project has been investigating a variety of machine learning approaches to particle track reconstruction. The most promising of these solutions, a graph neural network, processes the event as a graph that connects track measurements (detector hits corresponding to nodes) with candidate line segments between the hits (corresponding...
The P̅ANDA (antiP̅roton ANnihilation at Drmstadt) experiment at the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, will investigate the behavior of QCD in the mass range of the charmonium. As a fixed target experiment, most of the generated particle will have a forward boost. Therefore, the PANDA detector consists of a Central Spectrometer (CS), directly around...
Starting from 2020, future development projects for the Large Hadron Collider will constantly bring nominal luminosity increase, with the ultimate goal of reaching a peak luminosity of 5 · 1034 cm−2 s−1 for ATLAS and CMS experiments planned for the High Luminosity LHC (HL-LHC) upgrade. This rise in luminosity will directly result in an increased number of simultaneous proton collisions...
At the LHC, many proton-proton collisions are happening at a single beam crossing which leads to thousands of particles emerging from the interaction region and vast amount of data to be analyzed by the reconstruction software.
The finding of trajectories from charged particles in the tracking devices is a particularly challenging task due to two main factors. Firstly, deciding whether a...
Report from RAMP challenge November on fast vertexing
As a part of the future circular collider conceptual design study for hadron–hadron physics (FCC-hh), conceptual designs of the tracking detectors are being developed to facilitate the accurate measurement of particle products resulting from the 100-TeV collisions.
In the next decade, high-luminosity upgrades to the LHC will confront detectors with an order of magnitude increase in particle collisions. This will push track reconstruction software and hardware beyond current capabilities. The current track reconstruction approaches based on track seeding and track following allow for large contingency and hence are not optimal in terms of computational...
A full replacement of the muon trigger system in the CMS (Compact Muon Solenoid) detector is envisaged for operating at the maximum instantaneous luminosities expected in HL-LHC (High Luminosity Large Hadron Collider) of about $5-7.5x10^{34} cm^{-2}s^{-1}$. Under this scenario, the new on detector electronics that is being designed for the DT (Drift Tubes) detector will forward all the chamber...
The upcoming PANDA (anti-Proton ANnihilation at DArmstadt) experiment at FAIR (Facility for Anti-proton and Ion Research) offers unique possibilities for performing hyperon physics such as extraction of spin observables. Due to their relatively long-lived nature, the displaced decay vertices of hyperons impose a particular challenge on the track reconstruction and event building. The foreseen...
The LHCb experiment is dedicated to the study of the c- and b-hadrons decays, including long living particles such as Ks and strange baryons (Lambda, Xi, etc... ). These kind of particles are difficult to reconstruct from LHCb tracking systems since they escape the detection in the first tracker. In this talk the performance of the tracking algorithms for detecting long living particles are...
The alignment of the ATLAS Inner Detector is performed with a track-based algorithm. The aim of the detector alignment is to provide an accurate description of the detector geometry such that track parameters are accurately determined and bias free.
A new analysis with a detailed scrutiny of the track-hit residuals allows to study the deformation shape of the Pixels and IBL modules. The...
Timepix and Timepix3 Detectors are 256x256 hybrid active pixel detectors, capable of tracking ionizing particles as isolated clusters of pixels. To efficiently analyze such clusters at potentially high rates, we introduce multiple randomized pattern recognition algorithms inspired by computer vision. Offering desirable probabilistic bounds on accuracy and complexity, the presented methods are...
Having started data taking at the beginning of 2018, the Belle II experiment is a substantial upgrade of the Belle detector, operating at the SuperKEKB collider at the KEK laboratory in Japan. The experiment represents the cumulative effort from the collaboration of experimental and detector physics, computing, and software development. Taking everything learned from the previous Belle...
Building particle tracks is the most computationally intense step of event reconstruction at the LHC. With the increased instantaneous luminosity and associated increase in pileup expected from the High-Luminosity LHC, the computational challenge of track finding and fitting requires novel solutions. The current track reconstruction algorithms used at the LHC are based on Kalman-filter methods...
In LHC Run 3, ALICE will increase the data taking rate significantly to 50 kHz continuous readout of minimum bias Pb-Pb collisions instead of around 1 kHz triggered readout..
The reconstruction strategy of the online offline computing upgrade foresees a first synchronous online reconstruction stage during data taking enabling detector calibration, and a posterior calibrated asynchronous...
Computing time is becoming a key issue for tracking algorithms both online and off-line. Programming using adequate data structures can largely improve the efficiency of the reconstruction in terms of time response. We propose using one such data structure, called R-tree, that performs a fast, flexible and custom spatial indexing of the hits based on a neighbourhood organization. The overhead...
The CMS experiment at the LHC is designed to study a wide range of high energy physics phenomena. It employs a large all-silicon tracker within a 3.8T magnetic solenoid, which allows precise measurements of transverse momentum (pT) and vertex position.
This tracking detector will be upgraded to coincide with the installation of the High-Luminosity LHC, which will provide luminosities of up...
The tracking system of the Belle II consists of the silicon vertex detector and cylindrical drift chamber, both operating in a magnetic field created by the main solenoid of 1.5 T and final focusing magnets. The drift chamber consists of 56 layers of sense wires, arranged in interleaved axial and stereo superlayers, to assist track finding and provide full 3D tracking. The drift chamber serves...
Conformal tracking is the innovative track reconstruction strategy adopted for the detector designed for CLIC.
It features a pattern recognition in a conformal-mapped plane, where helix trajectories of charged particles in a magnetic field are projected into straight lines, followed by a Kalman-Filter-based fit in global space.
The nearest neighbour search is optimized by means of fast...
The High Luminosity LHC (HL-LHC) aims to increase the LHC data-set by an order of magnitude in order to increase its potential for discoveries. Starting from the middle of 2026, the HL-LHC is expected to reach the peak instantaneous luminosity of $7.5\times 10^{34}\text{cm}^{-2}\text{s}^{-1}$ which corresponds to up to about 200 inelastic proton-proton collisions per bunch crossing. To cope...
Beginning in 2021, the upgraded LHCb experiment will use a triggerless readout system collecting data at an event rate of 30 MHz. A software-only High Level Trigger will enable unprecedented flexibility for trigger selections. During the first stage (HLT1), a sub-set of the full offline track reconstruction for charged particles is run to select particles of interest based on single or...
The performances on data of the silicon standalone track finder based on the Sector Map concept developed for the Belle II vertex detector (VXD) will be presented.
The Belle II VXD is a combined tracking system composed by two layers of DEPFET pixel detectors married with four layers of double sided silicon strip sensors (SVD).
The VXD is recording e+ e- collisions occurring at the interaction...
To explore what our universe is made of, scientists at CERN are colliding protons, essentially recreating mini big bangs, and meticulously observing these collisions with intricate silicon detectors.
While orchestrating the collisions and observations is already a massive scientific accomplishment, analyzing the enormous amounts of data produced from the experiments is becoming an...
Remote sensing for earth observation is a tool that provides large information to monitor the vegetation, ice, water, sea levels, atmosphere temperature and wind, among other physical phenomena. This information comes in the form of multi and hyper spectral images covering the whole spectrum of emission of the sun. This information needs to be prepared and accommodated to be used, needs to be...
The CMOS sensors are emerging as one of the main candidate technologies for future tracking detectors in high luminosity colliders. Its capability of integrating the sensing diode into the CMOS wafer hosting the front-end electronics allows for reduced noise and higher signal sensitivity. They are suitable for high radiation environments due to the possibility of applying high depletion...
A variety of Beyond the Standard Model (BSM) theories predict new particles with macroscopic lifetimes of $c\tau\geq {\cal O}(1~{\rm mm})$ that could be created in proton-proton collisions at the Large Hadron Collider (LHC). Such theories often give rise to signatures that require dedicated tracking and vertexing techniques beyond conventional tracking algorithms. In this talk, a variety of...
We present a novel 4D fast tracking system, based on rad-hard pixel detectors and front-end electronics, capable of reconstructing four dimensional particle trajectories in real time using precise space and time information of the hits. The fast track finding system that we are proposing is designed for the high-luminosity phase of LHC and has embedded tracking capabilities. A massively...
The increasing track multiplicity in ATLAS poses new challenges for primary vertex reconstruction software, reaching to over 70 inelastic proton-proton collisions per beam crossing during Run-2 of the LHC and even more extreme vertex density in the next upcoming Runs. One way to get around these challenges, is to take a global approach to the track assignment to primary vertices, as opposed to...
A novel combination of data analysis techniques is proposed for the
reconstruction of all tracks of primary charged particles, as well as of
daughters of displaced vertices (decays, photon conversions, nuclear
interactions), created in high energy collisions. Instead of performing a
classical trajectory building or an image transformation, an efficient use of
both local and global information...
In the ATLAS experiment at the LHC, the primary-track reconstruction algorithm utilizes iterative track-finding seeded from combinations of silicon detector measurements. As all realistic combinations of space-points have been made, there are a number of track candidates where space-points overlap, or have been incorrectly assigned. This necessitates an ambiguity-solving stage. In the...
The physics goals the Belle II experiment require an exceptionally good alignment of all the components of the Belle II tracker. The Belle II tracker is composed of the DEPFET based pixel silicon detector, four layers of double sided silicon strip detector, a low material budget drift chamber, all three operating in a solenoidal 1.5 T B field, which is affected by the final focusing system of...
This contribution describes the experience with application of different ML methods to a physics analysis case. The use case chosen has been the classification of ttbar events coming from BSM or from SM and we have taken the datasets provided in a repository of simulated events. The features of these events are represented by their kinematic observables.
The initial objective was to compare...
To ensure particle tracking can be maintained in HEP colliders with high luminosity environments requires increased sensor granularity to keep the occupancies at levels acceptable for pattern recognition In addition the data must be readout fast enough to avoid pile up. Therefore the increase in luminosity and granularity requires read out of large data sets at high rates.
In ATLAS the data...
Pixel Front-End Controller (Pixel FEC) is responsible for programming the front-end chips and distributing the trigger, clock and fast signals to the modules in the CMS Phase-1 Pixel detector. An upgrade of the Pixel FEC firmware was undertaken and was successfully integrated within the online software. It was commissioned and deployed for the operation at the beginning of 2018. The upgrade...
Tracking in high density environments, particularly in high energy jets, plays an important role in many physics analyses at the LHC. In such environments, it is possible that two highly collinear particles contribute to the same hits as they travel through the ATLAS pixel detector and semiconductor tracker. If the two particles are sufficiently collinear, it is possible that only a single...
The LHC Run-III, scheduled to start taking data in 2021, will pose new challenges to event reconstruction as experiments are forced to move to more sophisticated software-based event filters to exploit the physics potential offered by the upgraded accelerator.
In particular, the LHCb experiment will install a new Vertex Locator (VELO), moving to pixel sensors with a trigger-less readout. ...
Vertex selection algorithms at the LHC have thus far relied primarily upon the hardness of the hard-scatter (HS) vertex relative to vertices from pileup (PU). The high PU environment at the HL-LHC will, however, introduce major experimental challenges for the correct selection of the HS vertex. In particular, the expected average PU vertex density of $~ 2$ $vtx/mm$ at $z=0$ can often lead to...
With the next-generation Timepix3 hybrid pixel detector, new possibilities and challenges have arisen. The Timepix3 segments active sensor area of 2cm² into a square matrix of 256 x 256 pixels. In each pixel, the ToA (Time of Arrival, with a precision of 1.56 ns) and ToT (Time over Threshold, energy) are measured simultaneously in data-driven, self-triggered, read-out scheme.
This...
In High Energy Physics (HEP), as in other fields, one frequently faces the problem of reconstructing the evolution of a dynamic system from a set of experimental measurements. Most of reconstruction programs use similar methods. However, in general they are reimplemented for each specific experimental setup. Some examples are fitting algorithms (i.e. Kalman Filter), equations for propagation,...
The CMS experiment at CERN will undergo significant improvements to cope with a 5-fold increase in instantaneous luminosity for the High Luminosity LHC (HL-LHC) era. In particular the endcap calorimetry will suffer from very high radiation levels and unprecedented event pile-up. The CMS HGCAL is being designed to replace the existing CMS endcap electromagnetic and hadronic calorimeters. It...
Many standard model extensions predict long-lived massive particles that can be detected by looking for displaced decay vertices in the inner detector volume. Current approaches to seek for these events in high-energy particle collisions rely on the presence of additional energetic signatures to make an online selection during data-taking. Enabling trigger-level reconstruction of displaced...
For the post High Luminosity LHC era, several accelerator projects are under study with an aim to increase the discovery potential for new physics at both the high energy and intensity frontier. The hadron-hadron based Future Circular Collider(FCC-hh) is one such project with the goal to collide proton-proton beams at $\sqrt{s} \sim 100$TeV with a bunch crossing rate of 25ns. Some of the major...
