scholarly journals The data acquisition and reduction challenge at the Large Hadron Collider

Author(s):  
Sergio Cittolin

The Large Hadron Collider detectors are technological marvels—which resemble, in functionality, three-dimensional digital cameras with 100 Mpixels—capable of observing proton–proton (pp) collisions at the crossing rate of 40 MHz. Data handling limitations at the recording end imply the selection of only one pp event out of each 10 5 . The readout and processing of this huge amount of information, along with the selection of the best approximately 200 events every second, is carried out by a trigger and data acquisition system, supplemented by a sophisticated control and monitor system. This paper presents an overview of the challenges that the development of these systems has presented over the past 15 years. It concludes with a short historical perspective, some lessons learnt and a few thoughts on the future.

2010 ◽  
Vol 25 (10) ◽  
pp. 749-766
Author(s):  
VIVIAN O'DELL

The CMS Trigger and Data Acquisition Systems have been installed and commissioned and are awaiting data at the Large Hadron Collider. In this article, we describe what factors drove the design and architecture of the systems.


2020 ◽  
Vol 245 ◽  
pp. 07044
Author(s):  
Frank Berghaus ◽  
Franco Brasolin ◽  
Alessandro Di Girolamo ◽  
Marcus Ebert ◽  
Colin Roy Leavett-Brown ◽  
...  

The Simulation at Point1 (Sim@P1) project was built in 2013 to take advantage of the ATLAS Trigger and Data Acquisition High Level Trigger (HLT) farm. The HLT farm provides around 100,000 cores, which are critical to ATLAS during data taking. When ATLAS is not recording data, such as the long shutdowns of the LHC, this large compute resource is used to generate and process simulation data for the experiment. At the beginning of the second long shutdown of the large hadron collider, the HLT farm including the Sim@P1 infrastructure was upgraded. Previous papers emphasised the need for simple, reliable, and efficient tools and assessed various options to quickly switch between data acquisition operation and offline processing. In this contribution, we describe the new mechanisms put in place for the opportunistic exploitation of the HLT farm for offline processing and give the results from the first months of operation.


2015 ◽  
Vol 30 (34) ◽  
pp. 1530061 ◽  
Author(s):  
Douglas M. Gingrich

The possibility of producing nonperturbative low-scale gravity states in collider experiments was first discussed in about 1998. The ATLAS and CMS experiments have searched for nonperturbative low-scale gravity states using the Large Hadron Collider with a proton–proton center-of-mass energy of 8 TeV. These experiments have now seriously confronted the possibility of producing nonperturbative low-scale gravity states which were proposed over 17 years ago. I will summarize the results of the searches, give a personal view of what they mean, and make some predictions for 13 TeV center-of-mass energy. I will also discuss early ATLAS 13 TeV center-of-mass energy results.


2018 ◽  
Vol 182 ◽  
pp. 02119
Author(s):  
Liaoshan Shi

In this report, we present the latest ATLAS results on the measurement of the cross sections and couplings of the Higgs boson in the fermionic decay modes, H → μ+μ-, H → τ+τ- and H → bb. The searches are performed with proton-proton collision data delivered by the Large Hadron Collider during Run 1 and the first two years of Run 2 at √s = 7, 8 and 13 TeV.


2013 ◽  
Vol 53 (A) ◽  
pp. 518-523
Author(s):  
Arno Straessner

The Large Hadron Collider (LHC) and the two multi-purpose detectors, ATLAS and CMS, have been operated successfully at record centre-of-mass energies of 7 ÷ 8TeV. This paper presents the main physics results from proton–proton collisions based on a total luminosity of 2 × 5 fb<sup>−1</sup>. The most recent results from Standard Model measurements, Standard Model and MSSM Higgs searches, as well as searches for supersymmetric and exotic particles are reported. Prospects for ongoing and future data taking are presented.


2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Ya-Hui Chen ◽  
Fu-Hu Liu ◽  
Roy A. Lacey

Transverse momentum (pT) and rapidity (y) spectra ofZbosons and quarkonium states (some charmoniumcc¯mesons such asJ/ψandψ(2S)and some bottomoniumbb¯mesons such asΥ(1S),Υ(2S), andΥ(3S)) produced in proton-proton (pp) and lead-lead (Pb-Pb) collisions at the large hadron collider (LHC) are uniformly described by a hybrid model of two-component Erlang distribution forpTspectrum and two-component Gaussian distribution foryspectrum. The former distribution results from a multisource thermal model, and the latter one results from the revised Landau hydrodynamic model. The modelling results are in agreement with the experimental data measured in pp collisions at center-of-mass energiess=2.76and 7 TeV and in Pb-Pb collisions at center-of-mass energy per nucleon pairsNN=2.76 TeV. Based on the parameter values extracted frompTandyspectra, the event patterns (particle scatter plots) in two-dimensionalpT-yspace and in three-dimensional velocity space are obtained.


2021 ◽  
Vol 251 ◽  
pp. 04019
Author(s):  
Andrei Kazarov ◽  
Adrian Chitan ◽  
Andrei Kazymov ◽  
Alina Corso-Radu ◽  
Igor Aleksandrov ◽  
...  

The ATLAS experiment at the Large Hadron Collider (LHC) operated very successfully in the years 2008 to 2018, in two periods identified as Run 1 and Run 2. ATLAS achieved an overall data-taking efficiency of 94%, largely constrained by the irreducible dead-time introduced to accommodate the limitations of the detector read-out electronics. Out of the 6% dead-time only about 15% could be attributed to the central trigger and DAQ system, and out of these, a negligible fraction was due to the Control and Configuration subsystem. Despite these achievements, and in order to improve even more the already excellent efficiency of the whole DAQ system in the coming Run 3, a new campaign of software updates was launched for the second long LHC shutdown (LS2). This paper presents, using a few selected examples, how the work was approached and which new technologies were introduced into the ATLAS Control and Configuration software. Despite these being specific to this system, many solutions can be considered and adapted to different distributed DAQ systems.


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