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D. Abbaneo,
G. Abbiendi,
M. Abbrescia,
S. Abdullin,
A. Abdulsalam,
B.S. Acharya,
D. Acosta,
J.G. Acosta,
A. Adair,
W. Adam, [......],
M.H. Zoeller,
O. Zorba,
P. Zotto,
W. Zou,
G. Zumerle,
M. Zupan,
A. Zuranski,
R. Zuyeuski,
M. Zvada,
P. Zych
[show abstract]
[hide abstract]
ABSTRACT: The Higgs boson was postulated nearly five decades ago within the framework of the standard model of particle physics and
has been the subject of numerous searches at accelerators around the world. Its discovery would verify the existence of a
complex scalar field thought to give mass to three of the carriers of the electroweak force—the W+, W–, and Z0 bosons—as well as to the fundamental quarks and leptons. The CMS Collaboration has observed, with a statistical significance
of five standard deviations, a new particle produced in proton-proton collisions at the Large Hadron Collider at CERN. The
evidence is strongest in the diphoton and four-lepton (electrons and/or muons) final states, which provide the best mass resolution
in the CMS detector. The probability of the observed signal being due to a random fluctuation of the background is about 1
in 3 × 106. The new particle is a boson with spin not equal to 1 and has a mass of about 1.25 giga–electron volts. Although its measured
properties are, within the uncertainties of the present data, consistent with those expected of the Higgs boson, more data
are needed to elucidate the precise nature of the new particle.
Science 12/2012; 338(6114):1569-1575. · 31.20 Impact Factor
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V. Andreev,
X. Aslanoglou,
A. Azman,
M. N. Bakirci,
S. Başeğmez, W. Beaumont,
J. Blocki,
K. Borras,
A. Campbell,
S. Çerçi, [......],
S. Reucroft,
M. Ripert,
K. Shileev,
K. Sogut,
J. Swain,
V. Tiflov,
A. Kayis-Topaksu,
H. Van Haevermaet,
P. Van Mechelen,
E. de Wolf
[show abstract]
[hide abstract]
ABSTRACT: We present performance studies of a full-length prototype for the CASTOR quartz-tungsten sampling calorimeter, installed in
the very forward region of the CMS experiment at the LHC. The response linearity and energy resolution, the uniformity, as
well as the showers’ spatial properties in the prototype have been studied with electrons, pions and muons of various energies.
A special study was also carried out for testing the light-output with a 90-degree cut of the quartz plates of the calorimeter.
The data were taken during the CASTOR test beam at CERN/SPS in 2007.
European Physical Journal C 04/2012; 67(3):601-615. · 3.63 Impact Factor
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M G Albrow,
R B Appleby,
M Arneodo,
G Atoian,
I L Azhgirey,
R Barlow,
I S Bayshev, W Beaumont,
L Bonnet,
A Brandt, [......],
M R M Warren,
G Weiglein,
T Wengler,
S N White,
B Winter,
Y Yao,
D Zaborov,
A Zampieri,
M Zeller,
A Zhokin
[show abstract]
[hide abstract]
ABSTRACT: We present the FP420 R&D project, which has been studying the key aspects of the development and installation of a silicon tracker and fast-timing detectors in the LHC tunnel at 420 m from the interaction points of the ATLAS and CMS experiments. These detectors would measure precisely very forward protons in conjunction with the corresponding central detectors as a means to study Standard Model (SM) physics, and to search for and characterise new physics signals. This report includes a detailed description of the physics case for the detector and, in particular, for the measurement of Central Exclusive Production, pp→p++p, in which the outgoing protons remain intact and the central system may be a single particle such as a SM or MSSM Higgs boson. Other physics topics discussed are γγ and γp interactions, and diffractive processes. The report includes a detailed study of the trigger strategy, acceptance, reconstruction efficiencies, and expected yields for a particular pp→pHp measurement with Higgs boson decay in the b mode. The document also describes the detector acceptance as given by the LHC beam optics between the interaction points and the FP420 location, the machine backgrounds, the new proposed connection cryostat and the moving (``Hamburg'') beam-pipe at 420 m, and the radio-frequency impact of the design on the LHC. The last part of the document is devoted to a description of the 3D silicon sensors and associated tracking performances, the design of two fast-timing detectors capable of accurate vertex reconstruction for background rejection at high-luminosities, and the detector alignment and calibration strategy.
Journal of Instrumentation 09/2009; 4(10):T10001. · 1.87 Impact Factor
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The CMS Collaboration,
S Chatrchyan,
G Hmayakyan,
V Khachatryan,
A M Sirunyan,
W Adam,
T Bauer,
T Bergauer,
H Bergauer,
M Dragicevic, [......],
G Abdullaeva,
A Avezov,
M I Fazylov,
E M Gasanov,
A Khugaev,
Y N Koblik,
M Nishonov,
K Olimov,
A Umaraliev,
B S Yuldashev
[show abstract]
[hide abstract]
ABSTRACT: The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 1034 cm−2 s−1 (1027 cm−2 s−1). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4π solid angle. Forward sampling calorimeters extend the pseudorapidity coverage to high values (|η| ≤ 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t.
Journal of Instrumentation 08/2008; 3(08):S08004. · 1.87 Impact Factor
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W Adam,
T Bergauer,
M Dragicevic,
M Friedl,
R Frühwirth,
S Hänsel,
J Hrubec,
M Krammer,
M Pernicka,
W Waltenberger, [......],
S Korjenevski,
D Miner,
D Orbaker,
L Christofek,
R Hooper,
G Landsberg,
D Nguyen,
M Narain,
T Speer,
K V Tsang
[show abstract]
[hide abstract]
ABSTRACT: During summer 2006 a fraction of the CMS silicon strip tracker was operated in a comprehensive slice test called the Magnet Test and Cosmic Challenge (MTCC). At the MTCC, cosmic rays detected in the muon chambers were used to trigger the readout of all CMS sub-detectors in the general data acquisition system and in the presence of the 4 T magnetic field produced by the CMS superconducting solenoid. This document describes the operation of the Tracker hardware and software prior, during and after data taking. The performance of the detector as resulting from the MTCC data analysis is also presented.
Journal of Instrumentation 07/2008; 3(07):P07006. · 1.87 Impact Factor
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M. G. Albrow,
R. B. Appleby,
M Arneodo,
G. Atoian,
I. L. Azhgirey,
R Barlow,
I. S. Bayshev, W Beaumont,
L. Bonnet,
A Brandt, [......],
M. R. M. Warren,
G. Weiglein,
T Wengler,
S N White,
B. Winter,
Y Yao,
D. Zaborov,
A Zampieri,
M. Zeller,
A Zhokin
[show abstract]
[hide abstract]
ABSTRACT: We present the FP420 R&D project, which has been studying the key aspects of the development and installation of a silicon tracker and fast-timing detectors in the LHC tunnel at 420 m from the interaction points of the ATLAS and CMS experiments. These detectors would measure precisely very forward protons in conjunction with the corresponding central detectors as a means to study Standard Model (SM) physics, and to search for and characterise New Physics signals. This report includes a detailed description of the physics case for the detector and, in particular, for the measurement of Central Exclusive Production, pp --> p + phi + p, in which the outgoing protons remain intact and the central system phi may be a single particle such as a SM or MSSM Higgs boson. Other physics topics discussed are gamma-gamma and gamma-p interactions, and diffractive processes. The report includes a detailed study of the trigger strategy, acceptance, reconstruction efficiencies, and expected yields for a particular p p --> p H p measurement with Higgs boson decay in the b-bbar mode. The document also describes the detector acceptance as given by the LHC beam optics between the interaction points and the FP420 location, the machine backgrounds, the new proposed connection cryostat and the moving ("Hamburg") beam-pipe at 420 m, and the radio-frequency impact of the design on the LHC. The last part of the document is devoted to a description of the 3D silicon sensors and associated tracking performances, the design of two fast-timing detectors capable of accurate vertex reconstruction for background rejection at high-luminosities, and the detector alignment and calibration strategy. Comment: 178 pages, 128 figures. Updated Timing section. Figures compressed to marginal resolution due to arxiv.org file size requirements. A higher quality document accessible at http://www.fp420.com/papers.html
06/2008;
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W Beaumont,
T. Beckers,
C. Van Dyck,
J. De Troy,
F Verbeure,
V Zhukov,
O Bouhali,
O Devroede,
F. Iacopi,
G De Lentdecker,
F Udo,
Er Velde,
W Van Doninck,
L Van Lancker,
K. Bernier,
I. Boulogne,
E Daubie
[show abstract]
[hide abstract]
ABSTRACT: Micro Strip Gas Counters with robust gold strips have been developed at IMEC, the Interuniversity Microelectronics Center at Leuven, in Belgium. The electroless plating technology was used, allowing to achieve a strip thickness of up to 1.6 m on 10x10 cm 2 substrates. Results on signal to noise ratio, spark rate, resulting damages and detector occupancy are presented for counters exposed to various intensities of heavily ionizing particles. a) On leave of absence from INP MSU, Moscow, present address: IIHE, ULB, Belgium b) Supported by the F.R.I.A., Fonds pour la Formation a la Recherche dans l'Industrie et l'Agriculture. c) Research director FWO d) Supported by the I.I.S.N., Institut Interuniversitaire des Sciences Nucleaires e) Collaborateur Scientifique F.N.R.S. 1 Introduction. Micro Strip Gas Counters (MSGC's) are foreseen to equip the outermost part of the CMS tracker [1]. It was shown by Monte Carlo simulations that the physics goals of the experiment can be ach...
12/1999;
-
[show abstract]
[hide abstract]
ABSTRACT: Results are presented from the exposure of a CMS performance prototype MSGC to a fast neutron beam having an average energy of 20 MeV and an intensity of 7 10 6 neutrons/mm 2 /s. A fluence equivalent to 3 years of LHC operation has been accumulated without damages to the detector. The stability of the MSGC operation in a heavily ionising particle flux is reported and the estimation of their production by neutrons is discussed. a) Research director FWO b) On leave of absence from INP MSU, Moscow c) Supported by the F.R.I.A., Fonds pour la Formation a la Recherche dans l'Industrie et l'Agriculture. d) Collaborateur Scientifique F.N.R.S. 1 Introduction In the CMS setup, the outer part of the inner tracker will be equiped with MSGC counters and, in this region, one expects a flux of 10 4 minimum ionizing particles (MIPS) per mm 2 and per second. The neutron flux in this region was estimated in [1] as 10 4 n/mm 2 /s (E n ? 100 KeV). Although these neutrons canno...
04/1998;
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Intensity Hadron Beam,
D Abbaneo,
E Albert,
F Angelini,
C Bastie, W Beaumont,
B. Bell,
R. Bellazzini,
M Bozzo,
I. Boulogne,
H Breuker,
A. Brez,
R Castaldi,
V Chorowicz,
A Giassi,
T. Henke,
L. Latronico,
M Loreti,
N. Lumb,
R. Malina
[show abstract]
[hide abstract]
ABSTRACT: A set of CMS MicroStrip Gas Chambers (MSGC) was exposed to a high intensity 3GeV=c pion beam at a CERN PS facility for a period of two weeks. The performance of the detectors is reported in terms of stability of efficiency and response to minimum ionising particles as well as to more heavily ionising fragments generated by nuclear interactions. Submitted to Nuclear Inst. and Methods in Physics Research, A 1) Organisation Europeene pour la Recherche Nucleaire, Geneve, Switzerland 2) Inter Universitaire Instelling Antwerpen, UIA, Antwerp, Belgium 3) Universita degli Studi and Istituto Nazionale Fisica Nucleare, Pisa, Italy 4) Inter University Institute for High Energies, ULD-VUB, Brussels, Belgium 5) Inter Universite Mons Hainaut, UMH, Mons, Belgium 6) Institut de Recherches Subatomiques, Strasbourg, France 7) Institut de Physique Nucleaire de Lyon, Villeurbanne, France 8) GRPHE, Universite de Haut Alsace, Mulhouse, France 9) Universitaa degli Studi and Istituto Nazional...
03/1998;
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W Adam,
T Bergauer,
M Dragicevic,
M Friedl,
R. Fruehwirth,
S. Haensel,
J Hrubec,
M Krammer,
M Oberegger,
M Pernicka, [......],
S. Korjenevski,
D Miner,
D Orbaker,
L Christofek,
R Hooper,
G Landsberg,
D Nguyen,
M Narain,
T Speer,
KV Tsang
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O Bouhali,
S Bachmann,
S. Barthe, W Beaumont,
T. Beckers,
F Beissel,
Ya Benhammou,
A M Bergdolt,
K. Bernier,
I. Boulogne, [......],
Fred Udo,
W K Van Doninck,
C. Van Dyck,
L Van Lancker,
C Van der Velde,
P Vanlaer,
P G Verdini,
R Wortmann,
A Zghiche,
V Zhukov
[show abstract]
[hide abstract]
ABSTRACT: The CMS MF1 milestone was set in order to evaluate system aspects of the CMS forward-backward MSGC tracker, to check the design and feasibility of mass production and to set up assembly and test procedures. We describe the construction and the experience gained with the operation of a system of 38 MSGC detectors assembled in six multi-substrate detector modules corresponding to the geometry of the forward-backward MSGC tracker in CMS. These modules were equipped with MSGCs mounted side by side, forming a continuous detector surface of about 0.2 m2. Different designs were tried for these modules. The problems encountered are presented with the proposed solutions. Operation conditions for the 38 MSGCs are reported from an exposure to a muon beam at the CERN SPS. Gain uniformity along the wedge-shaped strip pattern and across the detector modules are shown together with the detection efficiency, the spatial resolution, alignment and edge studies.
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O A Grachov,
B. Metzler,
M Murray,
J Snyder,
L. Stiles,
J Wood,
V Zhukova, W Beaumont,
S Ochesanu,
P. Debbins,
D Ingram,
E Norbeck,
Y. Onel,
E García
[show abstract]
[hide abstract]
ABSTRACT: The CMS Zero Degree Calorimeters, ZDCs, will measure photons and neutrons emitted with |eta|> 8.6 from Pb+Pb, p+Pb and p+p collisions at sqrt(Snn)=5.5, 8.8 and 14 TeV respectively. The calorimeter consists of an electromagnetic part segmented in the horizontal direction and an hadronic part segmented into four units in depth. In addition CMS will have access to data from a segmented shower maximum detector being built for luminosity measurements. We will present detailed results from tests beam measurements taken at the CERN SPS. These data will be used to extrapolate the utility of the ZDCs to measure photons, and possibly pi0s in p+p and ultra-peripheral heavy-ion collisions. Data from the hadronic section can be used to estimate the number of participants in heavy ion-collisions. In addition we will discuss plans to use the detector to measure the reaction plane, thereby extending the sensitivity of the central detectors in CMS.
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S. Chatrchyan,
G Hmayakyan,
V Khachatryan,
AM Sirunyan,
W Adam,
T Bauer,
T Bergauer,
H Bergauer,
M Dragicevic,
J. Ero, [......],
M. Baarmand,
L Baksay,
S Guragain,
M. Hohlmann,
H Mermerkaya,
R Ralich,
I Vodopiyanov,
MR Adams,
IM Anghel,
L Apanasevich
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MG Albrow,
RB Appleby,
M Arneodo,
G. Atoian,
IL Azhgirey,
R Barlow,
IS Bayshev, W Beaumont,
L. Bonnet,
A Brandt, [......],
MRM Warren,
G. Weiglein,
T Wengler,
SN White,
B. Winter,
Y Yao,
D. Zaborov,
A Zampieri,
M. Zeller,
A Zhokin
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W Adam,
T Bergauer,
M Dragicevic,
M Friedl,
R. Fruehwirth,
S. Haensel,
J Hrubec,
M Krammer,
M Oberegger,
M Pernicka, [......],
S. Korjenevski,
D Miner,
D Orbaker,
L Christofek,
R Hooper,
G Landsberg,
D Nguyen,
M Narain,
T Speer,
KV Tsang
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CMS Collaboration,
W Adam,
T Bergauer,
M Dragicevic,
M Friedl,
R. Fruehwirth,
S. Haensel,
J Hrubec,
M Krammer,
M Oberegger, [......],
S. Korjenevski,
D Miner,
D Orbaker,
L Christofek,
R Hooper,
G Landsberg,
D Nguyen,
M Narain,
T Speer,
KV Tsang
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W Adam,
T Bergauer,
M Dragicevic,
M Friedl,
R Frühwirth,
S Hansel,
J Hrubec,
M Krammer,
M Oberegger,
M Pernicka, [......],
S. Korjenevski,
D Miner,
D Orbaker,
L Christofek,
R Hooper,
G Landsberg,
D Nguyen,
M Narain,
T Speer,
K V Tsang
[show abstract]
[hide abstract]
ABSTRACT: The results of the CMS tracker alignment analysis are presented using the data from cosmic tracks, optical survey information, and the laser alignment system at the Tracker Integration Facility at CERN. During several months of operation in the spring and summer of 2007, about five million cosmic track events were collected with a partially active CMS Tracker. This allowed us to perform first alignment of the active silicon modules with the cosmic tracks using three different statistical approaches; validate the survey and laser alignment system performance; and test the stability of Tracker structures under various stresses and temperatures ranging from +15C to -15C. Comparison with simulation shows that the achieved alignment precision in the barrel part of the tracker leads to residual distributions similar to those obtained with a random misalignment of 50 (80) microns in the outer (inner) part of the barrel.
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M. Ageron,
A. Albert,
T. Barvich, W. Beaumont,
T. Beckers,
K. Bernier,
P. Blüm,
O. Bouhali,
I. Boulogne,
D. Bouvet, [......],
F. Udo,
W. Van Doninck,
C. Van Dyck,
C. Vander Velde,
P. Vanlaer,
L. Van Lancker,
T. Weiler,
A. Zander,
A. Zghiche,
V. Zhukov
[show abstract]
[hide abstract]
ABSTRACT: A system of detector modules consisting of a large size Gas Electron Multiplier (GEM), coupled to Micro Strip Gas Counters (MSGC), has been exposed to a pion beam at the Paul Scherrer Institute Cyclotron facility. As part of a CMS tracker milestone, the aim of this test was to investigate the robustness of such detectors when exposed to experimental conditions close to what is expected at the Large Hadron Collider (LHC) of CERN. Eighteen detector modules have been operated at voltage settings corresponding to 98% detection efficiency for Minimum Ionizing Particles during a period of 5 weeks. Sparking rates and strip losses have been monitored throughout the exposure. An operation margin of at least a factor of three with respect to the required gas gain has been demonstrated.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
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G. L. Bayatian,
S. Chatrchyan,
G Hmayakyan,
A M Sirunyan,
W Adam,
T Bergauer,
M Dragicevic,
J. Ero,
M Friedl,
R. Fruehwirth, [......],
D Reeder,
W.H. Smith,
D. Wenman,
G. S. Atoyan,
S Dhawan,
V. Issakov,
H Neal,
A. Poblaguev,
M. E. Zeller,
B. S. Yuldashev
[show abstract]
[hide abstract]
ABSTRACT: CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider ( LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking - through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start- up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb(-1) or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, B-s production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb(-1) to 30 fb(-1). The Standard Model processes include QCD, B-physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z(0) boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2-6 describe examples of full analyses, with photons, electrons, muons, jets, missing E-T, B-mesons and tau's, and for quarkonia in heavy ion collisions. Chapters 7-15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model.
Physics Research Publications.
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W Adam,
T Bergauer,
M Friedl,
R. Fruehwirth,
J Hrubec,
M Krammer,
M Pernicka,
W Waltenberger, W Beaumont,
E de Langhe, [......],
J Incandela,
S Kyre,
J Lamb,
R Taylor,
D White,
G Bolla,
D Bortoletto,
A. Garfinkel,
C Rott,
A Roy
[show abstract]
[hide abstract]
ABSTRACT: Inelastic nuclear collisions of hadrons incident on silicon sensors can generate secondary highly ionising particles (HIPs) and deposit as much energy within the sensor bulk as several hundred minimum ionising particles. The large signals generated by these 'HIP events' can momentarily saturate the APV25 front-end readout chip for the silicon strip tracker (SST) sub-detector of the compact muon solenoid (CMS) experiment, resulting in deadtime in the detector readout system. This paper presents studies of this phenomenon through simulation, laboratory measurements and dedicated beam tests. A proposed change to a front-end component to reduce the APV25 sensitivity to HIP events is also examined. The results are used to infer the expected effect on the performance of the CMS SST at the future large hadron collider. The induced inefficiencies are at the percent level and will have a negligible effect on the physics performance of the SST. (c) 2005 Elsevier B.V. All rights reserved.
Physics Research Publications.
