The silicon strip tracker of the CMS experiment has been completed and inserted into the CMS detector in late 2007. The largest sub-system of the tracker is its end cap system, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted into the TEC support structures. Each end cap consists of 144 petals, and the insertion of these petals into the end cap structure is referred to as TEC integration. The two end caps were integrated independently in Aachen (TEC+) and at CERN (TEC–). This note deals with the integration of TEC+, describing procedures for end cap integration and for quality control during testing of integrated sections of the end cap and presenting results from the testing. V. Adler, R. Adolphi, M. Ageron, J.-L. Agram, B. Atz, T. Barvich, G. Baulieu, W. Beaumont, F. Beissel, T. Bergauer, J.D. Berst, P. Blüm, E. Bock, F. Bögelsbacher, W. de Boer, J.-L. Bonnet, A. Bonnevaux, G. Boudoul, O. Bouhali, W. Braunschweig, R. Bremer (né Brauer), J.M. Brom, E. Butz, E. Chabanat, E. Chabert, B. Clerbaux, D. Contardo, B. De Callatay, P. Dehm, C. Delaere, R. Della Negra, J.-P. Dewulf, J. D’Hondt, F. Didierjean, A. Dierlamm, G. Dirkes, M. Dragicevic, F. Drouhin, J.P. Ernenwein, H. Esser, N. Estre, M. Fahrer, L. Feld, J. Fernandez, B. Florins, A. Flossdorf, G. Flucke, G. Flügge, J.C. Fontaine, K. Freudenreich, M. Frey, M. Friedl, A. Furgeri, N. Giraud, U. Goerlach, R. Goorens, P. Graehling, G. Gregoire, E. Gregoriev, L. Gross, S. Hänsel, R. Haroutunian, F. Hartmann, S. Heier, Th. Hermanns, D. Heydhausen, J. Heyninck, J. Hosselet, J. Hrubec, D. Jahn, P. Juillot, J. Kaminski, W. Karpinski, G. Kaussen, Th. Keutgen, R. Klanner, K. Klein, S. König, M. Kosbow, M. Krammer, B. Ledermann, V. Lemaitre, G. de Lentdecker, A. Linn, A. Lounis, K. Lübelsmeyer, N. Lumb, C. Maazouzi, T. Mahmoud, D. Michotte, O. Militaru, L. Mirabito, Th. Müller, L. Neukermans, C. Ollivetto, J. Olzem, A. Ostapchuk, D. Pandoulas, U. Pein, M. Pernicka, S. Perries, C. Piaseki, G. Pierschel, K. Piotrzkowski, M. Poettgens, O. Pooth, X. Rouby, A. Sabellek, S. Schael, N. Schirm, P. Schleper, S. Schmitz, A. Schultz von Dratzig, R. Siedling, H.-J. Simonis, A. Stahl, P. Steck, G. Steinbrück, M. Stoye, R. Strub, S. Tavernier, D. Teyssier, A. Theel, B. Trocme, F. Udo, M. Vander Donckt, C. Vander Velde, P. Van Hove, P. Vanlaer, L. Van Lancker, R. van Staa, S. Vanzetto, M. Weber, T. Weiler, S. Weseler, J. Wickens, B. Wittmer, M. Wlochal, E. de Wolf, V. Zhukov, M. H. Zoeller. 0) Corresponding author, katja.klein@rwth-aachen.de 1) Institut für Hochenergiephysik der Österreichischen Akademie der Wissenschaften (HEPHY), Vienna, Austria 2) Universiteit Antwerpen, Antwerpen, Belgium 3) Université Libre de Bruxelles (ULB), Brussels, Belgium 4) Vrije Universiteit Brussel (VUB), Brussels, Belgium 5) Institut de Physique Nucléaire, Université Catholique de Louvain, Louvain-la-Neuve, Belgium 6) Institut de Physique Nucléaire de Lyon, Université Claude Bernard Lyon-1, CNRS/IN2P3, Lyon, France 7) Groupe de Recherches en Physique des Hautes Energies (GRPHE), Université de Haute Alsace, Mulhouse, France 8) Institut Pluridisciplinaire Hubert Curien (IPHC), CNRS/IN2P3 et Université Louis Pasteur, Strasbourg, France 9) I. Physikalisches Institut, RWTH Aachen University, Aachen, Germany 10) III. Physikalisches Institut, RWTH Aachen University, Aachen, Germany 11) Institute for Experimental Physics, University of Hamburg, Hamburg, Germany 12) Institut fur Experimentelle Kernphysik (IEKP), Universität Karlsruhe, Karlsruhe, Germany 13) Eidgenössische Technische Hochschule, Zürich, Switzerland 14) Also at CERN, European Organization for Nuclear Research, Geneva, Switzerland 15) Now at CSIC-Universidad de Cantabria, Santander, Spain 16) Now at DESY, Hamburg, Germany 17) Now at Institute for Experimental Physics, University of Hamburg, Hamburg, Germany 18) Now at Paul Scherrer Institut, Villigen, Switzerland 19) Deceased 20) Now at Imperial College, London, England 21) Now at LPSC/INPG, Grenoble 1 University, France 22) Now at CERN, European Organization for Nuclear Research, Geneva, Switzerland 23) Also at INP MSU, Moscow, Russia

Using the ARGUS detector at the e+e storage ring DORIS II at DESY, we have studied lepton energy spectra in ~decays. We present a "pseudo-rest-frame" technique in which the second r in the event, decaying into a heavy hadronic system, is used as reference. This method allows for the first measurement of the Michel Parameter 7/ in ~decays. We also determine the Michel Parameter p in 7" --~ e~u decays with a precision comparable to the present world average. The measured values of the parameters p = 0.735 40.036 40.020 and r 1 = 0.03 40.18 40.12 are in good agreement with standard V-A coupling at the ~--~,-W vertex. 0370-2693/95/$09.50 Q 1995 Elsevier Science B.V. All rights reserved S S D I 0 3 7 0 2 6 9 3 ( 9 4 ) 0 1 3 8 6 1 442 ARGUS Collaboration/Physics Letters B 341 (1995) 441-447 Michel parameters [ 1-3 ] describing the space-time structure of the weak leptonic decays have been determined with high accuracy [4]. All values are in perfect agreement with the Standard Model predictions. The 7lepton discovered in 1975 [5], with its two leptonic decays 7" ~ e~ , and 7" --~/x~u, offers a unique opportunity to study the universality of the charged weak interaction. Describing the leptonic 7" decay by the most general four-fermion Hamiltonian we get the following matrix element [6]:

We report on the performance of a large micro-pattern detector with two gas electron multiplier foils and a two-layer readout structure at ground potential. The two readout layers each have a 406μm pitch and cross at an effective angle of 6.7°. This structure allows for two orthogonal coordinates to be determined. Using a muon beam at CERN together with a silicon tracking system, the position resolutions of the two coordinates are measured to be 50μm and 1 mm respectively (1 standard deviation). The muon detection efficiency for the two-dimensional space points reaches 96%. The detector was found to be well operational over a wide range in the settings of the different electrical fields.

An analysis of the reaction yy ~ r/c was l~erformed in five different decay channels of the r/c: /~sK+~r ~, K+K-Tr+~ ", 27r+21r , ~b~b and 2K+2K . A value Fry(r/c) = ( 11.3 + 4.2) keV was obtained for the radiative decay width by combining the results from the first four channels. Using our result on the two-photon width we also determined the branching ratio for the decay r/c --~ 2K+2K . 0370-2693/94/$07.00 (~) 1994 Elsevier Science B.V. All rights reserved SSDI 0 3 7 0 2 6 9 3 ( 9 4 ) 0 1 1 1 6-8 ARGUS Collaboration / Physics Letters B 338 (1994) 390-396 391 The measurements of the radiative decay widths of hadrons have proved to be one of the most important tools to study the composition and the properties of the bound states of strong interactions. While for light quarks the understanding of the binding forces is still on a more phenomenological level, in heavy quark systems, such as charmonium, fundamental tests of QCD dynamics can be made. One of the important quantities in the charmonium system is the relation between the leptonic decay width of the J/qt and the two-photon width of the r/c which is to the lowest order given by (see for example [ 1 ] ) Frr (r&) = 3e~( Ms/¢ )2. r,+e_ ( J l Cs ) " --~< QCD corrections have been calculated to order as by Barbieri et al. [2] resulting in the relation Frr(~7~) = Fete ( J / O ) " (1 ~a+O.OT~ which, together . . . . _0.05.1, with Fe+ e(J/~b) = (5.36:t:0.29) keV [31, yields the prediction Frr(r/c) = (8.6 + 0.6) keV. Furthermore, with the assumption that the hadronic r/c decays can be described by the lowest order two-gluon diagram one obtains the ratio of the hadronic to two-photon partial width Fhadrons(~'lc)/Fyr(rlc) proportional to ( a s / a ) 2. This relation could in principle be used to determine as. However, in this case the QCD radiative corrections seem to be too large to provide a reliable prediction. The radiative decay width Frt(r/~) has been measured by two different methods: in photon-photon collision experiments [4-7] and by the measurement of the process p/~ --* ~ [ 8 ]. The most significant results I DESY, IfH Zeuthen 2 Supported by the German Bundesministerium for Forschung und Technologic, under contract number 05413051P. 3 Supported by the German Bundesministerium for Forschung und Technologie, under contract number 056DDI 1P. 4 Supported by the German Bundesministerium ?dr Forschung und Technologie, under contract number 054ERI2R 5 Supported by the German Bundesministerium ?dr Forschung und Technologie, under contract number 055HD21P. 6 University of Toronto, Toronto, Ontario, Canada. 7 McGill University, Montreal, Quebec, Canada. 8 Supported by the Natural Sciences and Eagineering Research Council, Canada. 9 Supported by the German Bundesministerium ?dr Forschung und Technologie, under contract number 055KA l 1R l0 Supported by the Ministry of Science and Technology of the Republic of SIovenia and the Intemationales Bilro KfA, Jiilich. were obtained from the analysis of the decay channel r/¢ --* K~sK+cr :F, where a good identification of the/~s was achieved by determining its decay vertex. The results range from 4 to 27 keV and have large errors because of the small number of collected r& events and uncertainties in the knowledge of r/c branching ratios. The present analysis aims at improving the precision of the Fr~ (r/c) measurement by using several decay channels of the r/c meson. The data used in this analysis were collected using the ARGUS detector at the e+e storage ring DORIS II at DESY, and correspond to an integrated luminosity of 473 pb t . The beam energies varied between 4.7 and 5.3 GeV. The ARGUS detector and details about its trigger and its particle identification capabilities were described elsewhere [9]. In what follows, we describe the main features of the analysis, while details can be found in Refs. [10,11]. The two-photon production of the r/c was studied in e+e interactions via the reaction

Using the ARGUS detector at the e+e- storage ring DORIS II, we have searched for the real and imaginary part of the electric dipole formfactor d_tau of the tau lepton in the production of tau pairs at q^2=100 GeV^2. This is the first direct measurement of this CP violating formfactor. We applied the method of optimised observables which takes into account all available information on the observed tau decay products. No evidence for CP violation was found, and we derive the following results: Re(d_tau)=(1.6+-.9)*10^(-16) ecm and Im(d_tau)=(-0.2+-0.8)*10^(-16) ecm, where statistical and systematic errors have been combined.

This paper describes the performances of a large volume drift chamber with complete digitization of the output pulses. The electronics used in this test include wide-band (700MHz) amplifiers and fast (1 Gsample/s) digitizers. The gas mixture selected for drift chamber operation (80% He–20% CH4) and the signal processing mentioned above allow the measurement of the primary ionization clusters. The improvement in the (wire) impact parameter evaluation of the primary particle is sizeable.

In order to check the system aspects of the forward–backward MSGC tracker designed for the future CMS experiment at LHC, 38 trapezoidal MSGC counters assembled in six multi-substrates detector modules were built and exposed to a muon beam at the CERN SPS. Results on the gain uniformity along the wedge-shaped strip pattern and across the detector modules are shown together with measurements of the detection efficiency and the spatial resolution.

Using the ARGUS detector at the e(+)e(-) storage ring DORIS II, we have measured the Michel parameters rho,xi, and xi delta for tau(+/-) --> l (+/-) v (v) under bar decays in tau-pair events produced at center of mass energies in the region of the tau resonances. Using tau(-/+) --> rho(-/+) v as spin analyzing tags, we find rho(e) = 0.68 +/- 0.04 +/- 0.08, xi(e) = 1.12 +/- 0.20 +/- 0.09, xi delta(e) = 0.57 +/- 0.14 +/- 0.07, rho(mu)= 0.69 +/- 0.06 +/- 0.08, xi(mu) = 1.25 +/- 0.27 +/- 0.14 and xi delta(mu) = 0.72 +/- 0.18 +/- 0.10. In addition, we report the combined ARGUS results on rho, xi, and xi delta using this work and previous measurements. (C) 1998 Elsevier Science B.V. All rights reserved.

The performance of a prototype drift chamber operating in a He-based gas mixture as a specific ionisation detector is presented. In spite of the small number of primary ions, Helium performs quite satisfactorily in measuring energy losses for charged particles: with 50 GeV/c pions, we have measured in a 90% He-10% iC(4)H(10) mixture a relative energy loss resolution of 3.1% with 75 samples 3 cm long, using a modified Truncated Mean technique with 80% accepted fraction.The dependence of the resolution on several parameters such as the operating voltage, the truncation fraction, the number and length of the samples is discussed. (C) 1998 Elsevier Science B.V. All rights reserved.

The CP violation physics program and the detector design are described. The current status of KLOE is summarized.

The status of the construction of the KLOE Drift Chamber is reviewed. With its 4m diameter, it will be the biggest drift chamber ever built. The stringing of 52000 wires is a titanic effort: details are given about the semiautomatic system, the quality tests on wires and the monitoring of end-plates deformations.

For the first time an electrostatic method of wire tension measurement (WTM) is used for drift chamber construction. It became possible due to the use of a digital approach to sense the wire oscillations induced by an alternating potential. The method has excellent signal-to-noise ratio, high accuracy which is well above the stringing requirements and reasonable measuring time. The WTM system implemented in a CAMAC–Machintosh–Labview environment is now in use for the KLOE drift chamber stringing control and for monitoring the end-plate deformation.