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Combination of standard model Higgs searches at CDF

Proceedings of Science 120 (2010)

Abstract:

We present the latest combination of searches for a standard model (SM) Higgs boson in pp¯ collisions at √s = 1.96 TeV recorded by the CDF II detector at the Fermilab Tevatron. Using data corresponding to 2.3-5.9 fb−1 of integrated luminosity, we perform searches in a number of different production and decay modes and then combine them to improve sensitivity. No excess in data above that expected from backgrounds is observed; therefore, we set upper limits on the production cross section times branching fraction as a function of the SM Higgs boson mass (mH). The combined observed (expected) limit is 1.9 (1.8) times the SM prediction at mH = 115 GeV/c2 and 1.0 (1.1) times the SM prediction at mH = 165 GeV/c2.

Commissioning and performance of the CMS silicon strip tracker with cosmic ray muons

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:

During autumn 2008, the Silicon Strip Tracker was operated with the full CMS experiment in a comprehensive test, in the presence of the 3.8 T magnetic field produced by the CMS superconducting solenoid. Cosmic ray muons were detected in the muon chambers and used to trigger the readout of all CMS sub-detectors. About 15 million events with a muon in the tracker were collected. The efficiency of hit and track reconstruction were measured to be higher than 99% and consistent with expectations from Monte Carlo simulation. This article details the commissioning and performance of the Silicon Strip Tracker with cosmic ray muons. © 2010 IOP Publishing Ltd and SISSA.

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.

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.

CryoEDM: A cryogenic experiment to measure the neutron electric dipole moment

Journal of Physics: Conference Series 251:1 (2010)

Authors:

CA Baker, Balashov, V Francis, K Green, MGDVD Grinten, PS Iaydjiev, Ivanov, A Khazov, MAH Tucker, DL Wark, A Davidson, Grozier, M Hardiman, PG Harris, Karamath, K Katsika, JM Pendlebury, SJM Peeters, DB Shiers, PN Smith, CM Townsley, I Wardell, C Clarke, S Henry, Hans Kraus, M McCann, P Geltenbort, H Yoshiki

Abstract:

We have constructed an instrument, CryoEDM, to measure the neutron electric dipole moment to a precision of 10-28 e cm at the Institut Laue-Langevin. The main characteristic is that it is operating entirely in a cryogenic environment, at temperatures of 0.7 K within superfluid helium. Ultracold neutrons are produced in a superthermal source and stored within the superfluid in a storage cell which is held in a magnetic and electric field. NMR measurements are carried out to look for any shifts in the neutron Larmor precession frequency associated with the electric field and the neutrons are detected in-situ in the superfluid. Low temperature SQUID magnetometry is used to monitor the magnetic field. We report on the current status of the project that is now being commissioned and give an outlook on the future exploitation of the instrument. © 2010 IOP Publishing Ltd.