S. Paramesvaran

A new tracking detector is under development for use by the CMS experiment at the High-Luminosity LHC (HL-LHC). A crucial requirement of this upgrade is to provide the ability to reconstruct all charged particle tracks with transverse momentum above 2–3 GeV within 4 μs so they can be used in the Level-1 trigger decision. A concept for an FPGA-based track finder using a fully time-multiplexed architecture is presented, where track candidates are reconstructed using a projective binning algorithm based on the Hough Transform, followed by a combinatorial Kalman Filter. A hardware demonstrator using MP7 processing boards has been assembled to prove the entire system functionality, from the output of the tracker readout boards to the reconstruction of tracks with fitted helix parameters. It successfully operates on one eighth of the tracker solid angle acceptance at a time, processing events taken at 40 MHz, each with up to an average of 200 superimposed proton-proton interactions, whilst satisfying the latency requirement. The demonstrated track-reconstruction system, the chosen architecture, the achievements to date and future options for such a system will be discussed.

The Compact Muon Solenoid (CMS) experiment has implemented a sophisticated two-level online selection system that achieves a rejection factor of nearly 105. During Run II, the LHC will increase its centre-of-mass energy up to 13 TeV and progressively reach an instantaneous luminosity of 2 × 1034 cm−2 s−1. In order to guarantee a successful and ambitious physics programme under this intense environment, the CMS Trigger and Data acquisition (DAQ) system has been upgraded. A novel concept for the L1 calorimeter trigger is introduced: the Time Multiplexed Trigger (TMT) . In this design, nine main processors receive each all of the calorimeter data from an entire event provided by 18 preprocessors. This design is not different from that of the CMS DAQ and HLT systems. The advantage of the TMT architecture is that a global view and full granularity of the calorimeters can be exploited by sophisticated algorithms. The goal is to maintain the current thresholds for calorimeter objects and improve the performance for their selection. The performance of these algorithms will be demonstrated, both in terms of efficiency and rate reduction. The callenging aspects of the pile-up mitigation and firmware design will be presented.

When the LHC resumes operation in 2015, the higher centre-of-mass energy and high-luminosity conditions will require significantly more sophisticated algorithms to select interesting physics events within the readout bandwidth limitations. The planned upgrade to the CMS calorimeter trigger will achieve this goal by implementing a flexible system based on the μTCA standard, with modules based on Xilinx Virtex-7 FPGAs and up to 144 optical links running at speeds of 10 Gbps. The upgrade will improve the energy and position resolution of physics objects, enable much improved isolation criteria to be applied to electron and tau objects and facilitate pile-up subtraction to mitigate the effect of the increased number of interactions occurring in each bunch crossing. The design of the upgraded system is summarised with particular emphasis placed on the results of prototype testing and the experience gained which is of general application to the design of such systems.

A new tracking system is under development for operation in the CMS experiment at the High Luminosity LHC. It includes an outer tracker which will construct stubs, built by correlating clusters in two closely spaced sensor layers for the rejection of hits from low transverse momentum tracks, and transmit them off-detector at 40 MHz. If tracker data is to contribute to keeping the Level-1 trigger rate at around 750 kHz under increased luminosity, a crucial component of the upgrade will be the ability to identify tracks with transverse momentum above 3 GeV/c by building tracks out of stubs. A concept for an FPGA-based track finder using a fully time-multiplexed architecture is presented, where track candidates are identified using a projective binning algorithm based on the Hough Transform. A hardware system based on the MP7 MicroTCA processing card has been assembled, demonstrating a realistic slice of the track finder in order to help gauge the performance and requirements for a full system. This paper outlines the system architecture and algorithms employed, highlighting some of the first results from the hardware demonstrator and discusses the prospects and performance of the completed track finder.

Results from the completed Phase 1 Upgrade of the Compact Muon Solenoid (CMS) Level-1 Calorimeter Trigger are presented. The upgrade was performed in two stages, with the first running in 2015 for proton and heavy ion collisions and the final stage for 2016 data taking. The Level-1 trigger has been fully commissioned and has been used by CMS to collect over 43 fb−1 of data since the start of the Run II of the Large Hadron Collider (LHC). The new trigger has been designed to improve the performance at high luminosity and large number of simultaneous inelastic collisions per crossing (pile-up). For this purpose it uses a novel design, the Time Multiplexed Trigger (TMT), which enables the data from an event to be processed by a single trigger processor at full granularity over several bunch crossings. The TMT design is a modular design based on the μTCA standard. The trigger processors are instrumented with Xilinx Virtex-7 690 FPGAs and 10 Gbps optical links. The TMT architecture is flexible and the number of trigger processors can be expanded according to the physics needs of CMS. Sophisticated and innovative algorithms are now the core of the first decision layer of the experiment. The system has been able to adapt to the outstanding performance of the LHC, which ran with an instantaneous luminosity well above design. The performance of the system for single physics objects are presented along with the optimizations foreseen to maintain the thresholds for the harsher conditions expected during the LHC Run II and Run III periods.

Selected results from tau analyses performed using the BaBar detector at the SLAC National Accelerator Laboratory are presented. A precise measurement of the tau mass and the tau{+} tau{-} mass difference is undertaken using the hadronic decay mode tau- --> pi+ pi- pi- nu. In addition an investigation into the strange decay modes tau- --> K0S pi- pi0 nu and tau- --> K0S pi- nu is also presented, including a fit to the tau- --> K0S pi-nu invariant mass spectrum. Precise values for the Mass and Width of the K*(892) are obtained.

The Compact Muon Solenoid (CMS) employs a sophisticated two-level online triggering system that has a rejection factor of up to 105. Since the beginning of Run II of LHC, the conditions that CMS operates in have become increasingly challenging. The centre-of-mass energy is now 13 TeV and the instantaneous luminosity currently peaks at 1.5 ×1034 cm−2s−1. In order to keep low physics thresholds and to trigger efficiently in such conditions, the CMS trigger system has been upgraded. A new trigger architecture, the Time Multiplexed Trigger (TMT) has been introduced which allows the full granularity of the calorimeters to be exploited at the first level of the online trigger. The new trigger has also benefited immensely from technological improvements in hardware. Sophisticated algorithms, developed to fully exploit the advantages provided by the new hardware architecture, have been implemented. The new trigger system started taking physics data in 2016 following a commissioning period in 2015, and since then has performed extremely well. The hardware and firmware developments, electron and photon algorithms together with their performance in challenging 2016 conditions is presented.

The Compact Muon Solenoid (CMS) experiment at CERN is scheduled for a major upgrade in the next decade in order to meet the demands of the new High Luminosity Large Hadron Collider.Amongst others, a new tracking system is under development including an outer tracker capable of rejecting low transverse momentum particles by looking at the coincidences of hits (stubs) in two closely spaced sensor layers in the same tracker module.Accepted stubs are transmitted off-detector for further processing at 40 MHz.In order to maintain under the increased luminosity the Level-1 trigger rate at 750 kHz, tracker data need to be included in the decision making process.For this purpose, a system architecture has to be developed that will be able to identify particles with transverse momentum above 3 GeV/c by building tracks out of stubs, while achieving an overall processing latency of maximum 4us.Targeting these requirements the current paper presents an FPGA-based track finding architecture that identifies track candidates in real-time and bases its functionality on a fully time-multiplexed approach.As a proof of concept, a hardware system has been assembled targeting the MP7 MicroTCA processing card that features a Xilinx Virtex-7 FPGA, demonstrating a realistic slice of the track finder.The paper discusses the algorithms' implementation and the efficient utilisation of the available FPGA resources, it outlines the system architecture, and presents some of the hardware demonstrator results.

Selected results from {tau} analyses performed using the BABAR detector at the SLAC National Accelerator Laboratory are presented. A precise measurement of the {tau} mass and the {tau}{sup +}{tau}{sup -} mass difference is undertaken using the hadronic decay mode {tau}{sup {+-}} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup {+-}}{nu}{sub {tau}}. In addition an investigation into the strange decay modes {tau}{sup -} {yields} K{sub S}{sup 0}{pi}{sup -}{pi}{sup 0}{nu}{sub {tau}} and {tau}{sup -} {yields} K{sub S}{sup 0}{pi}{sup -}{nu}{sub {tau}} is also presented, including a fit to the {tau}{sup -} {yields} K{sub S}{sup 0}{pi}{sup -}{nu}{sub {tau}} invariant mass spectrum. Precise values for M(K*(892)) and {Lambda}(K*(892)) are obtained.

Abstract The DUNE neutrino experiment far detector has a fiducial mass of 40 kt. The O(1M) readout channels are distributed over the four 10 kt modules and need to be synchronized with respect to each other to a precision of O(10 ns). The entire system needs to be synchronized with respect to GPS time to O(100 ns). The system needs to be reliable, simple and affordable. Clock and synchronization information are encoded on the same fibre using a protocol based on duty cycle shift keying (DCSK) with 8b10b encoding to ensure DC-balance. The use of DCSK allows the clock to be recovered directly by PLL based clock generators without needing to use a separate clock and data recovery (CDR) device. Small scale tests show a timing jitter at the endpoint of ≈10 ps with respect to the timing master.

The High-Luminosity LHC will open an unprecedented window on the weak-scale nature of the universe, providing high-precision measurements of the standard model as well as searches for new physics beyond the standard model. Such precision measurements and searches require information-rich datasets with a statistical power that matches the high-luminosity provided by the Phase-2 upgrade of the LHC. Efficiently collecting those datasets will be a challenging task, given the harsh environment of 200 proton-proton interactions per LHC bunch crossing. For this purpose, the trigger and data acquisition system of the Compact Muon Solenoid (CMS) experiment will be entirely replaced. Novel design choices have been explored, including ATCA prototyping platforms with SoC controllers and newly available interconnect technologies with serial optical links with data rates up to 28 Gb/s. Trigger data analysis will be performed through sophisticated algorithms, including widespread use of Machine Learning, in large FPGAs, such as the Xilinx Ultrascale family. The system will process over 60 Tb/s of detector data with an event rate of 750 kHz. Since the Technical Design Report was approved comprehensive progress has been made in several areas related to prototyping hardware platforms, optical interconnect testing, algorithm development in HLS and VHDL, as well testing between subsystems on real hardware. Recent results in all these areas will be presented.

The CMS Level-1 calorimeter trigger is being upgraded in two stages to maintain performance as the LHC increases pile-up and instantaneous luminosity in its second run. In the first stage, improved algorithms including event-by-event pile-up corrections are used. New algorithms for heavy ion running have also been developed. In the second stage, higher granularity inputs and a time-multiplexed approach allow for improved position and energy resolution. Data processing in both stages of the upgrade is performed with new, Xilinx Virtex-7 based AMC cards.

The CMS collaboration is preparing a major upgrade of its detector, so it can operate during the high luminosity run of the LHC from 2026. The upgraded tracker electronics will reconstruct the trajectories of charged particles within a latency of a few microseconds, so that they can be used by the level-1 trigger. An emulation framework, CIDAF, has been developed to provide a reference for a proposed FPGA-based implementation of this track finder, which employs a Time-Multiplexed (TM) technique for data processing.

The Compact Muon Solenoid (CMS) experiment is currently installing upgrades to their Calorimeter Trigger for LHC Run 2 to ensure that the trigger thresholds can stay low, and physics data collection will not be compromised. The electronics will be upgraded in two stages. Stage-1 for 2015 will upgrade some electronics and links from copper to optical in the existing calorimeter trigger so that the algorithms can be improved and we do not lose valuable data before stage-2 can be fully installed by 2016. Stage-2 will fully replace the calorimeter trigger at CMS with a micro-TCA and optical link system. It requires that the updates to the calorimeter back-ends, the source of the trigger primitives, be completed. The new system's boards will utilize Xilinx Virtex-7 FPGAs and have hundreds of high-speed links operating at up to 10 Gbps to maximize data throughput. The integration, commissioning, and installation of stage-1 in 2015 will be described, as well as the integration and parallel installation of the stage-2 in 2015, for a fully upgraded CMS calorimeter trigger in operation by 2016.

Run 2 of the LHC represents one of the most challenging scientific environments for real time data analysis and processing. The steady increase in instantaneous luminosity will result in the CMS detector producing around 150 TB/s of data, only a small fraction of which is useful for interesting Physics studies. During 2015 the CMS collaboration will be completing a total upgrade of its Level 1 Trigger to deal with these conditions. In this talk a description of the major components of this complex system will be described. This will include a discussion of custom-designed electronic processing boards, built to the uTCA specification with AMC cards based on Xilinx 7 FPGAs and a network of high-speed optical links. In addition, novel algorithms will be described which deliver excellent performance in FPGAs and are combined with highly stable software frameworks to ensure a minimal risk of downtime. This upgrade is planned to take data from 2016. However a system of parallel running has been developed that will allow CMS to install, commission and operate it alongside the current Trigger to assess and validate performance with LHC collision data. This systems combination of state-of-the-art electronics, firmware and software could have many interesting applications for particle physics, astronomy and other areas. Presented at ACAT2016 17th International workshop on Advanced Computing and Analysis Techniques in physics research The next step in real time data processing for large scale Physics experiments Sudarshan Paramesvaran, on behalf of the CMS Collaboration University of Bristol, Bristol BS8 1TH, UK E-mail: sudarshan.paramesvaran@bristol.ac.uk Abstract. Run 2 of the LHC represents one of the most challenging scientific environments for real time data analysis and processing. The steady increase in instantaneous luminosity will result in the CMS detector producing around 150 TB/s of data, only a small fraction of which is useful for interesting Physics studies. During 2015 the CMS collaboration will be completing a total upgrade of its Level 1 Trigger to deal with these conditions. In this talk a description of the major components of this complex system will be described. This will include a discussion of custom-designed electronic processing boards, built to the uTCA specification with AMC cards based on Xilinx 7 FPGAs and a network of high-speed optical links. In addition, novel algorithms will be described which deliver excellent performance in FPGAs and are combined with highly stable software frameworks to ensure a minimal risk of downtime. This upgrade is planned to take data from 2016. However a system of parallel running has been developed that will allow CMS to install, commission and operate it alongside the current Trigger to assess and validate performance with LHC collision data. This system’s combination of state-of-the-art electronics, firmware and software could have many interesting applications for particle physics, astronomy and other areas. Run 2 of the LHC represents one of the most challenging scientific environments for real time data analysis and processing. The steady increase in instantaneous luminosity will result in the CMS detector producing around 150 TB/s of data, only a small fraction of which is useful for interesting Physics studies. During 2015 the CMS collaboration will be completing a total upgrade of its Level 1 Trigger to deal with these conditions. In this talk a description of the major components of this complex system will be described. This will include a discussion of custom-designed electronic processing boards, built to the uTCA specification with AMC cards based on Xilinx 7 FPGAs and a network of high-speed optical links. In addition, novel algorithms will be described which deliver excellent performance in FPGAs and are combined with highly stable software frameworks to ensure a minimal risk of downtime. This upgrade is planned to take data from 2016. However a system of parallel running has been developed that will allow CMS to install, commission and operate it alongside the current Trigger to assess and validate performance with LHC collision data. This system’s combination of state-of-the-art electronics, firmware and software could have many interesting applications for particle physics, astronomy and other areas.

The hadron calorimeters of the CMS experiment have successfully recorded data at 7 TeV and 8 TeV center-of-mass energy during 2011 and 2012 LHC operation. The performance of all systems (barrel, end-cap, forward and the outer calorimeters) are discussed and results from the full 2011 dataset are shown on noise rejection, calibration, collision timing, and identification of jet candidates and for other salient features. In addition, the CMS collaboration is planning improvements to the hadron calorimeters which include the replacement of the HPD photodetectors with SiPMs, increased depth segmentation in the calorimeter, and the inclusion of TDC capability. The status of the Research and Development for these upgrades will be discussed, including the testing of the upgraded microTCA readout electronics during current LHC data taking.

The hadron calorimeters of the CMS experiment have successfully recorded data at 7 TeV and 8 TeV center-of-mass energy during 2011 and 2012 LHC operation. The performance of all systems (barrel, end-cap, forward and the outer calorimeters) are discussed and results from the full 2011 dataset are shown on noise rejection, calibration, collision timing, and identification of jet candidates and for other salient features. In addition, the CMS collaboration is planning improvements to the hadron calorimeters which include the replacement of the HPD photodetectors with SiPMs, increased depth segmentation in the calorimeter, and the inclusion of TDC capability. The status of the Research and Development for these upgrades will be discussed, including the testing of the upgraded microTCA readout electronics during current LHC data taking.

A new tracking detector is under development for use by the CMS experiment at the High-Luminosity LHC (HL-LHC).A crucial component of this upgrade will be the ability to reconstruct within a few microseconds all charged particle tracks with transverse momentum above 3 GeV, so they can be used in the Level-1 trigger decision.A concept for an FPGA-based track finder using a fully time-multiplexed architecture is presented, where track candidates are reconstructed using a projective binning algorithm based on the Hough Transform followed by a track fitting based on the linear regression technique.A hardware demonstrator using MP7 processing boards has been assembled to prove the entire system, from the output of the tracker readout boards to the reconstruction of tracks with fitted helix parameters.It successfully operates on one eighth of the tracker solid angle at a time, processing events taken at 40 MHz, each with up to 200 superimposed proton-proton interactions, 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.