The high instantaneous luminosities expected following the upgrade of the Large Hadron Collider (LHC) to the High-Luminosity LHC (HL-LHC) pose major experimental challenges for the CMS experiment. A ...central component to allow efficient operation under these conditions is the reconstruction of charged particle trajectories and their inclusion in the hardware-based trigger system. There are many challenges involved in achieving this: a large input data rate of about 20–40 Tb/s processing a new batch of input data every 25 ns, each consisting of about 15,000 precise position measurements and rough transverse momentum measurements of particles (“stubs”); performing the pattern recognition on these stubs to find the trajectories; and producing the list of trajectory parameters within 4 μs. This paper describes a proposed solution to this problem, specifically, it presents a novel approach to pattern recognition and charged particle trajectory reconstruction using an all-FPGA solution. The results of an end-to-end demonstrator system, based on Xilinx Virtex-7 FPGAs, that meets timing and performance requirements are presented along with a further improved, optimized version of the algorithm together with its corresponding expected performance.
Measurement and monitoring of the luminosity in the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN will be essential both for physics measurements (e.g., production ...cross-sections of top, Higgs and SUSY) and for accurate simulation of rate dependent detector characteristics. Our proposal for a CMS luminosity monitoring system consists of a set of small angle diamond pixel telescopes. These telescopes are situated close to the beam pipe where radiation levels are very high and room for mechanical structures and services is quite limited. The CMS pixel readout chip provides a fast over-threshold signal that will be used to monitor the bunch-to-bunch luminosity variations by counting the number of particles that hit the telescope array in each beam crossing. The proposed system will determine the individual bunch-to-bunch luminosity variations to a precision of better than 1% over a 1
s time scale.
In this paper, we review recent theoretical progress and the latest experimental results in jet substructure from the Tevatron and the LHC. We review the status of and outlook for calculation and ...simulation tools for studying jet substructure. Following up on the report of the Boost 2010 workshop, we present a new set of benchmark comparisons of substructure techniques, focusing on the set of variables and grooming methods that are collectively known as 'top taggers'. To facilitate further exploration, we have attempted to collect, harmonize and publish software implementations of these techniques.
These proceedings are a summary of four lectures given at the Theoretical Advanced Study Institute in Elementary Particle Physics (TASI) in 2009. These lectures provide a basic introduction to ...experimental particle physics and the Large Hadron Collider experiments at CERN, with many general examples from the (still running) Fermilab Tevatron.
Measurement of the K L Charge Asymmetry Alavi-Harati, A.; Alexopoulos, T.; Arenton, M. ...
Physical review letters,
05/2002, Letnik:
88, Številka:
18
Journal Article
We present results of a search for a new form of hadronic matter, a six-quark, dibaryon state called the H{sup 0} , a state predicted to exist in several theoretical models. Analyzing data collected ...by experiment E799-II at Fermilab, we searched for the decay H{sup 0}{yields}{lambda}p{pi}{sup -} and found no candidate events. We place an upper limit on B(H{sup 0}{yields}{lambda}p{pi}{sup -} )d{sigma}{sub H}/d{omega}/( d{sigma}{sub {xi}}/d{omega}) and, in the context of published models, exclude the region of lightly bound mass states just below the {lambda}{lambda} mass threshold, 2.194<M{sub H}<2.231 GeV /c{sup 2} , with lifetimes from {approx}5x10{sup -10} sec to {approx}1x10{sup -3} sec . (c) 2000 The American Physical Society.
The high instantaneous luminosities expected following the upgrade of the Large Hadron Collider (LHC) to the High Luminosity LHC (HL-LHC) pose major experimental challenges for the CMS experiment. A ...central component to allow efficient operation under these conditions is the reconstruction of charged particle trajectories and their inclusion in the hardware-based trigger system. There are many challenges involved in achieving this: a large input data rate of about 20--40 Tb/s; processing a new batch of input data every 25 ns, each consisting of about 15,000 precise position measurements and rough transverse momentum measurements of particles ("stubs''); performing the pattern recognition on these stubs to find the trajectories; and producing the list of trajectory parameters within 4 \(\mu\,\)s. This paper describes a proposed solution to this problem, specifically, it presents a novel approach to pattern recognition and charged particle trajectory reconstruction using an all-FPGA solution. The results of an end-to-end demonstrator system, based on Xilinx Virtex-7 FPGAs, that meets timing and performance requirements are presented along with a further improved, optimized version of the algorithm together with its corresponding expected performance.
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