OPMD

Research group

Research theme

Sub department

About

Related research groups

Identification and filtering of uncharacteristic noise in the CMS hadron calorimeter

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:

Commissioning studies of the CMS hadron calorimeter have identified sporadic uncharacteristic noise and a small number of malfunctioning calorimeter channels. Algorithms have been developed to identify and address these problems in the data. The methods have been tested on cosmic ray muon data, calorimeter noise data, and single beam data collected with CMS in 2008. The noise rejection algorithms can be applied to LHC collision data at the trigger level or in the offline analysis. The application of the algorithms at the trigger level is shown to remove 90% of noise events with fake missing transverse energy above 100 GeV, which is sufficient for the CMS physics trigger operation. © 2010 IOP Publishing Ltd and SISSA.
More details from the publisher

Measurement of the charge ratio of atmospheric muons with the CMS detector

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 692:2 (2010) 83-104

Authors:

V Khachatryan, AM Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Erö, C Fabjan, M Friedl, R Frühwirth, VM Ghete, J Hammer, S Hänsel, M Hoch, N Hörmann, J Hrubec, M Jeitler, G Kasieczka, W Kiesenhofer, M Krammer, D Liko, I Mikulec, M Pernicka, H Rohringer, R Schöfbeck, J Strauss, A Taurok, F Teischinger, W Waltenberger, G Walzel, E Widl, CE Wulz, V Mossolov, N Shumeiko, J Suarez Gonzalez, L Benucci, L Ceard, EA De Wolf, M Hashemi, X Janssen, T Maes, L Mucibello, S Ochesanu, B Roland, R Rougny, M Selvaggi, H Van Haevermaet, P Van Mechelen, N Van Remortel, V Adler, S Beauceron, S Blyweert, J D'Hondt, O Devroede, A Kalogeropoulos, J Maes, M Maes, S Tavernier, W Van Doninck, P Van Mulders, I Villella, EC Chabert, O Charaf, B Clerbaux, G De Lentdecker, V Dero, APR Gay, GH Hammad, PE Marage, C Vander Velde, P Vanlaer, J Wickens, S Costantini, M Grunewald, B Klein, A Marinov, D Ryckbosch, F Thyssen, M Tytgat, L Vanelderen, P Verwilligen, S Walsh, N Zaganidis, S Basegmez, G Bruno, J Caudron, J De Favereau De Jeneret, C Delaere, P Demin, D Favart, A Giammanco, G Grégoire, J Hollar, V Lemaitre, O Militaru, S Ovyn, D Pagano, A Pin, K Piotrzkowski, L Quertenmont

Abstract:

We present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interactions in the atmosphere, using data collected by the CMS detector both at ground level and in the underground experimental cavern at the CERN LHC. Muons were detected in the momentum range from 5 GeV/. c to 1 TeV/. c. The surface flux ratio is measured to be 1.2766±0.0032(stat.)±0.0032(syst.), independent of the muon momentum, below 100 GeV/. c. This is the most precise measurement to date. At higher momenta the data are consistent with an increase of the charge ratio, in agreement with cosmic ray shower models and compatible with previous measurements by deep-underground experiments. © 2010.
More details from the publisher
More details
Details from ArXiV

Measurement of the muon stopping power in lead tungstate

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:

A large sample of cosmic ray events collected by the CMS detector is exploited to measure the specific energy loss of muons in the lead tungstate (PbWO4) of the electromagnetic calorimeter. The measurement spans a momentum range from 5 GeV/c to 1 TeV/c. The results are consistent with the expectations over the entire range. The calorimeter energy scale, set with 120 GeV/c electrons, is validated down to the sub-GeV region using energy deposits, of order 100 MeV, associated with low-momentum muons. The muon critical energy in PbWO4 is measured to be 160+5-68 GeV, in agreement with expectations. This is the first experimental determination of muon critical energy. © 2010 IOP Publishing Ltd and SISSA.
More details from the publisher

Observation of long-range, near-side angular correlations in proton-proton collisions at the LHC

Journal of High Energy Physics 2010:9 (2010)

Authors:

V Khachatryan, AM Sirunyan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Erö, C Fabjan, M Friedl, R Frühwirth, VM Ghete, J Hammer, S Hänsel, C Hartl, M Hoch, N Hörmann, J Hrubec, M Jeitler, G Kasieczka, W Kiesenhofer, M Krammer, D Liko, I Mikulec, M Pernicka, H Rohringer, R Schöfbeck, J Strauss, A Taurok, F Teischinger, W Waltenberger, G Walzel, E Widl, CE Wulz, V Mossolov, N Shumeiko, J Suarez Gonzalez, L Benucci, L Ceard, EA De Wolf, X Janssen, T Maes, L Mucibello, S Ochesanu, B Roland, R Rougny, M Selvaggi, H Van Haevermaet, P Van Mechelen, N Van Remortel, V Adler, S Beauceron, S Blyweert, J D'Hondt, O Devroede, A Kalogeropoulos, J Maes, M Maes, S Tavernier, W Van Doninck, P Van Mulders, I Villella, EC Chabert, O Charaf, B Clerbaux, G De Lentdecker, V Dero, APR Gay, GH Ham-Mad, T Hreus, PE Marage, C Vander Velde, P Vanlaer, J Wickens, S Costantini, M Grunewald, B Klein, A Marinov, D Ryckbosch, F Thyssen, M Tytgat, L Vanelderen, P Verwilligen, S Walsh, N Zaganidis, S Basegmez, G Bruno, J Caudron, J De Favereau De Jeneret, C Delaere, P Demin, D Favart, A Giammanco, G Grégoire, J Hollar, V Lemaitre, O Militaru, S Ovyn, D Pagano, A Pin, K Piotrzkowski

Abstract:

Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (η) and azimuthal angle (φ). Short-range correlations in Δη, which are studied in minimum bias events, are characterized using a simple "independent cluster" parametrization in order to quantify their strength (cluster size) and their extent in η (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 nb-1 data set at 7TeV. In high multiplicity events, a pronounced structure emerges in the two-dimensional correlation function for particle pairs with intermediate px of 1-3 GeV/c, 2.0 < |Δη| < 4.8 and Δφ ≈0. This is the first observation of such a long-range, near-side feature in two-particle correlation functions in pp or pp̄ collisions. © SISSA 2010.
More details from the publisher
Details from ArXiV

Performance and operation of the CMS electromagnetic calorimeter

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 operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75 848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented. © 2010 IOP Publishing Ltd and SISSA.
More details from the publisher