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Commissioning of the CMS experiment and the cosmic run at four tesla

Journal of Instrumentation 5:3 (2010)

Authors:

S Chatrchyan, V Khachatryan, AM Sirunyan, W Adam, B Arnold, H Bergauer, T Bergauer, M Dragicevic, M Eichberger, J Erö, M Friedl, R Frühwirth, VM Ghete, J Hammer, S Hansel, M Hoch, N Hörmann, J Hrubec, M Jeitler, G Kasieczka, K Kastner, M Krammer, D Liko, I De Magrans Abril, I Mikulec, F Mittermayr, B Neuherz, M Oberegger, M Padrta, M Pernicka, H Rohringer, S Schmid, R Schöfbeck, T Schreiner, R Stark, H Steininger, J Strauss, A Taurok, F Teischinger, T Themel, D Uhl, P Wagner, W Waltenberger, G Walzel, E Widl, CE Wulz, V Chekhovsky, O Dvornikov, I Emeliantchik, A Litomin, V Makarenko, I Marfin, V Mossolov, N Shumeiko, A Solin, R Stefanovitch, J Suarez Gonzalez, A Tikhonov, A Fedorov, A Karneyeu, M Korzhik, V Panov, R Zuyeuski, P Kuchinsky, W Beaumont, L Benucci, M Cardaci, EA De Wolf, E Delmeire, D Druzhkin, M Hashemi, X Janssen, T Maes, L Mucibello, S Ochesanu, R Rougny, M Selvaggi, H Van Haevermaet, P Van Mechelen, N Van Remortel, V Adler, S Beauceron, S Blyweert, J D'Hondt, S De Weirdt, O Devroede, J Heyninck, A Kalogeropoulos, J Maes, M Maes, MU Mozer, S Tavernier, W Van Doninck, P Van Mulders, I Villella, O Bouhali, EC Chabert, O Charaf, B Clerbaux, G De Lentdecker

Abstract:

The CMS Collaboration conducted a month-long data-taking exercise known as the Cosmic Run At Four Tesla in late 2008 in order to complete the commissioning of the experiment for extended operation. The operational lessons resulting from this exercise were addressed in the subsequent shutdown to better prepare CMS for LHC beams in 2009. The cosmic data collected have been invaluable to study the performance of the detectors, to commission the alignment and calibration techniques, and to make several cosmic ray measurements. The experimental setup, conditions, and principal achievements from this data-taking exercise are described along with a review of the preceding integration activities. © 2010 IOP Publishing Ltd and SISSA.
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Commissioning of the CMS High-Level Trigger with cosmic rays

Journal of Instrumentation 5:3 (2010)

Authors:

S Chatrchyan, V Khachatryan, AM Sirunyan, W Adam, B Arnold, H Bergauer, T Bergauer, M Dragicevic, M Eichberger, J Erö, M Friedl, R Frühwirth, VM Ghete, J Hammer, S Hansel, M Hoch, N Hörmann, J Hrubec, M Jeitler, G Kasieczka, K Kastner, M Krammer, D Liko, I De Magrans Abril, I Mikulec, F Mittermayr, B Neuherz, M Oberegger, M Padrta, M Pernicka, H Rohringer, S Schmid, R Schöfbeck, T Schreiner, R Stark, H Steininger, J Strauss, A Taurok, F Teischinger, T Themel, D Uhl, P Wagner, W Waltenberger, G Walzel, E Widl, CE Wulz, V Chekhovsky, O Dvornikov, I Emeliantchik, A Litomin, V Makarenko, I Marfin, V Mossolov, N Shumeiko, A Solin, R Stefanovitch, J Suarez Gonzalez, A Tikhonov, A Fedorov, A Karneyeu, M Korzhik, V Panov, R Zuyeuski, P Kuchinsky, W Beaumont, L Benucci, M Cardaci, EA De Wolf, E Delmeire, D Druzhkin, M Hashemi, X Janssen, T Maes, L Mucibello, S Ochesanu, R Rougny, M Selvaggi, H Van Haevermaet, P Van Mechelen, N Van Remortel, V Adler, S Beauceron, S Blyweert, J D'Hondt, S De Weirdt, O Devroede, J Heyninck, A Kalogeropoulos, J Maes, M Maes, MU Mozer, S Tavernier, W Van Doninck, P Van Mulders, I Villella, O Bouhali, EC Chabert, O Charaf, B Clerbaux, G De Lentdecker

Abstract:

The CMS High-Level Trigger (HLT) is responsible for ensuring that data samples with potentially interesting events are recorded with high efficiency and good quality. This paper gives an overview of the HLT and focuses on its commissioning using cosmic rays. The selection of triggers that were deployed is presented and the online grouping of triggered events into streams and primary datasets is discussed. Tools for online and offline data quality monitoring for the HLT are described, and the operational performance of the muon HLT algorithms is reviewed. The average time taken for the HLT selection and its dependence on detector and operating conditions are presented. The HLT performed reliably and helped provide a large dataset. This dataset has proven to be invaluable for understanding the performance of the trigger and the CMS experiment as a whole. © 2010 IOP Publishing Ltd and SISSA.
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Drift Time Measurement in the ATLAS Liquid Argon Electromagnetic Calorimeter using Cosmic Muons

European Physical Journal C 70:3 (2010) 755-785

Authors:

The ATLAS Collaboration, G Aad, B Abbott, J Abdallah, AA Abdelalim, A Abdesselam, O Abdinov, B Abi, M Abolins, H Abramowicz, H Abreu, BS Acharya, DL Adams, TN Addy, J Adelman, C Adorisio, P Adragna, T Adye, S Aefsky, JA Aguilar-Saavedra, M Aharrouche, SP Ahlen, F Ahles, A Ahmad, H Ahmed, M Ahsan, G Aielli, T Akdogan, TPA Åkesson, G Akimoto, AV Akimov, A Aktas, MS Alam, MA Alam, J Albert, S Albrand, M Aleksa, IN Aleksandrov, F Alessandria, C Alexa, G Alexander, G Alexandre, T Alexopoulos, M Alhroob, M Aliev, G Alimonti, J Alison, M Aliyev, PP Allport, SE Allwood-Spiers, J Almond, A Aloisio, R Alon, A Alonso, MG Alviggi, K Amako, C Amelung, VV Ammosov, A Amorim, G Amorós, N Amram, C Anastopoulos, T Andeen, CF Anders, KJ Anderson, A Andreazza, V Andrei, XS Anduaga, A Angerami, F Anghinolfi, N Anjos, A Antonaki, M Antonelli, S Antonelli, J Antos, B Antunovic, F Anulli, S Aoun, G Arabidze, I Aracena, Y Arai, ATH Arce, JP Archambault, S Arfaoui, JF Arguin, T Argyropoulos, E Arik, M Arik, AJ Armbruster, O Arnaez, C Arnault, A Artamonov, D Arutinov, M Asai, S Asai, R Asfandiyarov, S Ask, B Åsman, D Asner, L Asquith

Abstract:

The ionization signals in the liquid argon of the ATLAS electromagnetic calorimeter are studied in detail using cosmic muons. In particular, the drift time of the ionization electrons is measured and used to assess the intrinsic uniformity of the calorimeter gaps and estimate its impact on the constant term of the energy resolution. The drift times of electrons in the cells of the second layer of the calorimeter are uniform at the level of 1.3% in the barrel and 2.8% in the endcaps. This leads to an estimated contribution to the constant term of (0.290.040.05)% in the barrel and (0.540.040.06)% in the endcaps. The same data are used to measure the drift velocity of ionization electrons in liquid argon, which is found to be 4.61±0.07 mm/μs at 88.5 K and 1 kV/mm. © 2010 CERN for the benefit of the ATLAS collaboration.
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Events with an isolated lepton and missing transverse momentum and measurement of W production at HERA

Journal of High Energy Physics 2010:3 (2010)

Authors:

FD Aaron, H Abramowicz, I Abt, L Adamczyk, M Adamus, M Aldaya Martin, C Alexa, V Andreev, S Antonelli, P Antonioli, A Antonov, B Antunovic, M Arneodo, V Aushev, O Bachynska, S Backovic, A Baghdasaryan, A Bamberger, AN Barakbaev, G Barbagli, G Bari, F Barreiro, E Barrelet, W Bartel, D Bartsch, M Basile, K Begzsuren, O Behnke, J Behr, U Behrens, L Bellagamba, A Belousov, A Bertolin, S Bhadra, M Bindi, JC Bizot, C Blohm, T Bołd, EG Boos, M Borodin, K Borras, D Boscherini, D Bot, V Boudry, SK Boutle, I Bozovic-Jelisavcic, J Bracinik, G Brandt, M Brinkmann, V Brisson, I Brock, E Brownson, R Brugnera, N Brümmer, D Bruncko, A Bruni, G Bruni, B Brzozowska, A Bunyatyan, G Buschhorn, PJ Bussey, JM Butterworth, B Bylsma, L Bystritskaya, A Caldwell, AJ Campbell, KB Cantun Avila, M Capua, R Carlin, CD Catterall, K Cerny, V Cerny, S Chekanov, V Chekelian, A Cholewa, J Chwastowski, J Ciborowski, R Ciesielski, L Cifarelli, F Cindolo, A Contin, JG Contreras, AM Cooper-Sarkar, N Coppola, M Corradi, F Corriveau, M Costa, JA Coughlan, G Cozzika, J Cvach, G D’Agostini, JB Dainton, F Dal Corso, K Daum, M Deák, J de Favereau, B Delcourt, M Del Degan, J del Peso, J Delvax

Abstract:

A search for events containing an isolated electron or muon and missing transverse momentum produced in e±p collisions is performed with the H1 and ZEUS detectors at HERA. The data were taken in the period 1994-2007 and correspond to an integrated luminosity of 0.98 fb-1. The observed event yields are in good overall agreement with the Standard Model prediction, which is dominated by single W production. In the e+p data, at large hadronic transverse momentum PTX < 25GeV, a total of 23 events are observed compared to a prediction of 14.0 ±1.9. The total single W boson production cross section is measured as 1.06 ± 0.16 (stat.) ± 0.07 (sys.) pb, in agreement with an Standard Model (SM) expectation of 1.26 ± 0.19 pb.
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Fine synchronization of the CMS muon drift-tube local trigger using cosmic rays

Journal of Instrumentation 5:3 (2010)

Authors:

S Chatrchyan, V Khachatryan, AM Sirunyan, W Adam, B Arnold, H Bergauer, T Bergauer, M Dragicevic, M Eichberger, J Erö, M Friedl, R Frühwirth, VM Ghete, J Hammer, S Hansel, M Hoch, N Hörmann, J Hrubec, M Jeitler, G Kasieczka, K Kastner, M Krammer, D Liko, I De Magrans Abril, I Mikulec, F Mittermayr, B Neuherz, M Oberegger, M Padrta, M Pernicka, H Rohringer, S Schmid, R Schöfbeck, T Schreiner, R Stark, H Steininger, J Strauss, A Taurok, F Teischinger, T Themel, D Uhl, P Wagner, W Waltenberger, G Walzel, E Widl, CE Wulz, V Chekhovsky, O Dvornikov, I Emeliantchik, A Litomin, V Makarenko, I Marfin, V Mossolov, N Shumeiko, A Solin, R Stefanovitch, J Suarez Gonzalez, A Tikhonov, A Fedorov, A Karneyeu, M Korzhik, V Panov, R Zuyeuski, P Kuchinsky, W Beaumont, L Benucci, M Cardaci, EA De Wolf, E Delmeire, D Druzhkin, M Hashemi, X Janssen, T Maes, L Mucibello, S Ochesanu, R Rougny, M Selvaggi, H Van Haevermaet, P Van Mechelen, N Van Remortel, V Adler, S Beauceron, S Blyweert, J D'Hondt, S De Weirdt, O Devroede, J Heyninck, A Kalogeropoulos, J Maes, M Maes, MU Mozer, S Tavernier, W Van Doninck, P Van Mulders, I Villella, O Bouhali, EC Chabert, O Charaf, B Clerbaux, G De Lentdecker

Abstract:

The CMS experiment uses self-triggering arrays of drift tubes in the barrel muon trigger to perform the identification of the correct bunch crossing. The identification is unique only if the trigger chain is correctly synchronized. In this paper, the synchronization performed during an extended cosmic ray run is described and the results are reported. The random arrival time of cosmic ray muons allowed several synchronization aspects to be studied and a simple method for the fine synchronization of the Drift Tube Local Trigger at LHC to be developed. © 2010 IOP Publishing Ltd and SISSA.
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