1

Division I Sciences humaines et socialesDivision II Mathématiques, sciences naturelles et de l'ingénieurDivision III Biologie et médecineAdresse case postale 8232, 3001 BerneTéléphone +41 (0)31 308 22 22Telefax +41 (0)31 301 30 09e-mail div1@snf.ch / div2@snf.ch / div3@snf.ch

Rapport scientifique

intermédiaire final

Un rapport est considéré comme final lorsque la durée du subside est écoulée. Lerapport doit être envoyé au Fonds national en deux exemplaires. Prière d'établir unrésumé et de répondre en page 2 à chaque question de manière à éviter toutmalentendu. La signature personnelle du/de la bénéficiaire responsable doit figurer enpage 2 des deux exemplaires du rapport; elle est indispensable pour la validité de cedernier.Toute question, proposition ou remarque ne concernant pas directement le rapport doitêtre transmise séparément au FNRS.

Ce rapport concerne le subside no: 20-68'092.02Il est établi pour la période du 01.10.2002 au 30.09.2003

Titre du projet de recherche: High-Energy Hadron Interactions : CDF at the Tevatron and ATLAS at the CERN LHC

Nom et prénom du/de la bénéficiaire: CLARK AllanTéléphone direct : 022 379 62 75 Date de remise du rapport: 14.11.2003Téléphone secrétariat: 022 379 63 69 e-mail: Allan.Clark@cern.ch

Avez-vous obtenu un subside pour poursuivre ce projet?oui, numéro 200020-101975 nonRésumé (10-15 lignes) des résultats obtenus et de leur signification; ce résumé peutêtre mis à la disposition de milieux intéressés.

Hadron interactions at the highest possible collision energies allow a detailed study of theStandard Model for strong and electroweak interactions, as well as stringent searches forextensions or deviations from the Standard Model.

The CDFII detector has collected a total of 270pb-1 since data taking started in April 2001, at acollision energy of √s = 1.96 TeV. Of that 200 pb-1 is of physics analysis quality, nearly twicethe previous total. Data taking will continue until at least 2007.

Construction of the ATLAS detector at the CERN Large Hadron Collider (LHC) is well advanced,and the experiment is expected to collect data from 2007 at a pp collision energy of Vs = 14TeV.

2

a) Résumé (2-4 pages) des résultats obtenus et de leur signification :• Présentez en grandes lignes l'avancement de vos recherches en y

situant les publications parues, soumises et prévues, mentionnées ci-dessous aux points b), c) et d).

• Citez les principaux résultats acquis.• Indiquez schématiquement les contributions de vos employé(e)s

FNS.• Commentez le cas échéant les modifications significatives

apportées au plan de recherche prévu.• Indiquez des événements importants (mutations au niveau du

personnel, participation à des conférences, distinctions scientifiques,etc.).

Veuillez utiliser des feuilles séparées.

b) Publications résultant des recherches effectuées: un exemplaire de chaquepublication parue au cours de la période subsidiée est à joindre à ce rapport (pourla Division I, joindre deux exemplaires de chaque publication).Veuillez en établir la liste sur une feuille séparée.

c) Publications à l'impression: veuillez nous remettre ces publications (avecmention du numéro du subside) avec votre prochain rapport ; s’il s’agit ici d’unrapport final, veuillez nous envoyer un exemplaire des publications dès leurparution.

Veuillez en établir la liste sur une feuille séparée.

d) Autres publications: prévoyez-vous d'autres publications découlant de cetterecherche?

oui non

Si oui, veuillez nous remettre ces publications (avec mention du numéro dusubside) avec votre prochain rapport ; s’il s’agit ici d’un rapport final, veuilleznous envoyer un exemplaire des publications dès leur parution.

e) Brevets:

Les démarches nécessaires ont-elles été ou vont-elles être entreprises ?

oui non

Si oui, veuillez indiquer le nom du déposant, le titre et le numéro du brevet oucommuniquez-nous ces indications en temps voulu.

Lieu et date: Signature du/de labénéficiaire responsable:

Genève, le 11 novembre 2003Annexes (points a-c, e)nombre total de pages 34

Dans leurs rapports finaux, les bénéficiaires responsables doivent donner desrenseigne-ments détaillés au sujet de l’état et de l’utilisation future du matériel de valeur durable

(unités d’un prix d’acquisition supérieur à CHF 20'000.-)acquis grâce au subsidedu FNS (cf. art. 42 du Règlement relatif aux octrois de subsides).

3

a) HIGH-ENERGY INTERACTIONS: CDF AT THE TEVATRONAND ATLAS DETECTOR AT THE CERN LHC

Responsibles: A. G. Clark, A. Blondel, X. Wu.

Physicists: M. Campanelli, M. Mangin-Brinet, B. Mikulec, I. Riu, L. Rosselet, A. Straessner

Doctoral students:M. Diaz Gomez, M. Donega, M. D’Onofrio, Y. Liu, S. Moëd, A. Sfyrla, S. Vallecorsa,A. Zsenei

+ Departmental technical support.

ATLAS development and construction activities at the University of Geneva (DPNC) arefocussed on:- the fabrication, test and integration of forward silicon modules, meeting stringent

electrical and mechanical specifications, for the high-precision central silicontracking detector (SCT) of ATLAS;

- the design and construction of 4 carbon fibre sandwich cylinders and associatedbrackets to support silicon modules of the SCT, and the subsequent mechanical andsystem integration of the assembled barrel detector layers;

- the development, construction and integration of off-detector read-out electronics(“RODs”) for the Liquid Argon calorimeter of ATLAS;

- data acquisition associated with the electronics developments noted above; and- the development of analysis activities in preparation for data collection.

A detailed triennial report was presented in February 2003 [1]. This brief summaryconcentrates on activities since that time:- the final preparation and start of forward silicon module assembly and test;- the delivery and furbishing of the barrel support for SCT modules;- integration activities related to the SCT;- assembly and test of the final pre-production prototype (ROD) motherboard for read-

out of the ATLAS Liquid Argon calorimeter;- simulation and computing activities with the physics groups of the ATLAS

Collaboration.

The declared objectives for the period October 2002 - September 2003 were not met, fortwo reasons:- equipment funding cuts prevented or delayed some planned activities, and limited

travel funds prevented a proper participation at a number of important ATLAS andCDF activities;

- delays of component supply due to technical quality control issues delayed (andcontinues to delay) the fabrication of modules as described below.

4

The upgraded CDF experiment (CDFII) has collected data from pp collisions at anenergy of √s = 1.96 TeV since April 2001, and has been fully commissioned sinceJanuary 2002. A total integrated luminosity of 270 pb-1 has been collected, of which 200pb-1 is of physics quality. Machine limitations have restricted the collection of data andthe total integrated luminosity until 2007 has been revised downwards to ~3- 4 fb-1. Forthis reason Fermilab has cancelled a planned Run 2B silicon upgrade. The Geneva groupcontinues its maintenance responsibilities for the CDF silicon trigger (SVT), andparticipates in operational activities. Physics analyses by the group since the March 2003report are also summarised below.

A.1. THE ATLAS DETECTOR AT LHC

A.1.1 The ATLAS Silicon Tracker (SCT)

A. SCT module component procurement and quality assurance

Figure 1 shows an exploded view of the different module components for the SCTforward silicon modules.

Figure 1 : Exploded view of the SCT outer forward module. The figure shows back-to-back silicon detectors sandwiching a TPG cooling spine, and AlN cross-bars formechanical strength. The hybrid is at the end of the detector.

The silicon sensor procurement and quality assurance (QA) is complete, including anadditional order for spares due to losses resulting from more extended moduleprototyping than anticipated. The quality of delivered sensors was excellent, with <1% ofwafers outside specifications (see section 3.2.1 of [1]).

5

The Geneva group is partly responsible for the supply of the front-end ABCD3Telectronic readout chip, previously developed by the CERN, Cracow and Geneva groups.The ABCD3T is fabricated by ATMEL S.A. in a radiation hard DMILL technology. Atotal of 924 wafers were ordered and a subsequent order of 37 wafers was made forspares.a) The tolerance of the ABCD3T chips to proton and neutron irradiation is less than

expected on the basis of initial prototype studies. This is a concern for the long termtracker performance in ATLAS (see below). An initiative to develop an equivalentchip using a deep submicron process (IBM) was not chosen by the collaboration.

b) ATMEL has announced the closing of their production line in December 2003, and hasdelivered only 85% of the chips. ATMEL and CERN are currently negotiating asolution to this problem. In practice, defective chips will be used, resulting in a smalldetector inefficiency.

The other components suffering from procurement problems are the central spine, and thehybrid.

The central spine of the module is a key component, since it uses high conductivitycarbon (TPG) to thermally cool the modules. They are fabricated in Russia, in acooperation agreement with MPI (Munich). Supplies have been delayed by contractualissues, and by poor QA.

The hybrid is a complex structure consisting of a multi-layer kapton film that is glued toa carbon substrate that supplies a crucial themal path to the cooling tubes.a) The electrical behaviour of the hybrid satisfies the required technical specifications

before irradiation, but does not meet the design specifications after radiation from 24GeV protons of 1.5 x 1014 p. cm-2 (50% of the maximum dose expected after 10 yearsof LHC operation). This is largely due to the ABCD3T chip performance, and isdescribed below and in [1]. Despite this, the hybrid is expected to remain functionalfor the full 10 year period.

b) The fabrication by Cicorel S.A. and the subsequent furbishing and test by Hybrid S.A.have been suspended because of problems of de-lamination between the kapton filmand the carbon substrate. The problem is being investigated.

B. SCT module construction and quality assurance.

Figure 2 shows a forward SCT module. The Geneva is responsible for the constructionof 624 forward modules (including spares) and has developed module assembly and QAfacilities to meet that requirement. These facilities are fully functional.

6

Figure 2 : Photograph of an SCT outer forward module (K5 hybrid).

The design and the fabrication of new jigs for the assembly phase 1 (detector to spineassembly) and assembly phase 2 (Hybrid attachment with the fanins) were completed. Inthe assembly phase 1, 3 sets of jigs were made: the detector transfer plates (to suck thedetector once they are aligned to the microns relative to reference pins), the gluing base(receiving the 2 transfer plates and the spine and its handling frame). In the assemblyphase 2, 3 sets were made which are composed of: the main jig that receives theassembled detector to spine and the hybrids, the fanin bridges, the handling system forthe location pad (see Figure 3).

Figure 3 : Phase 2 assembly – Fixation of the precision location pad

7

All the assembly sets have been tested with dummy modules and pre-series electricalmodules. Based on the excellent results obtained with the XY survey of all the modulesmade so far (the tail of the distributions are at less than half of the tolerance – see Figure4 below), we are confident of meeting the required QA using the Geneva tooling. The Zsurvey of the detector surface showed good results inside the tolerances of +/- 115microns. Nevertheless, the wide spread of the profiles is a concern. It is thought that abowing of the spines and sensors may result in a stressed spine-detector structure afterglueing. The glue layer can absorb a part of this effect, but it has been decided to rejectany spines that show a distortion of more than 0.5 mm.

The wire bonding is the last step of the assembly and remains an important and delicateoperation. The H&K 815 wire bonder bought last year is a success but close operatorcontrol remains important, and is a limitation to the speed. Problems includecontamination or oxidation of the wire bonding pads, and accumulated dust. Whenanomalies are detected, the automatic operation is stopped and a manual intervention ismade with newly optimized bonding parameters. Only 4 wires remained unbonded(~0.0046% failure).

The key issues remaining are:a) The facilities, and available technical staff, permit the construction of 2 modules per

day, allowing in practice the construction of 624 modules in 18-20 months. Because ofdifficulties of component supply only 15 production modules had been fabricated, ofwhich 14 satisfied the mechanical and electrical specification. The ATLAS schedulerequires the completion of module production by September 2004, which is evidentlyincompatible with the planned production rate.

b) The module production rate could be increased by operating 2 or more shifts. Thissolution would require additional skilled technical staff, and additional jigs, withresulting financial implications.

c) Even if a solution can be found, it is unlikely that the component procurement can besignificantly improved.

At each stage of the module production, QA is enforced for the components before themodule assembly, and the metrology and functionality of the module during and afterassembly. The tests that are performed during production are summarized below :a) Tests before the module assembly:

- The silicon sensors are re-tested immediately before assembly in a dry N2

atmosphere. The I-V dependence is measured at bias voltages up to 500 volts.- A rigorous visual and electrical hybrid inspection is made before assembly. Typical

problems include damaged chips, broken bond wires, etc.b) Tests during and after the module assembly:

- I-V tests are made following each assembly step- The module is fully tested before and after thermal cycling, before being sent for

long-term tests and burn-in.

8

A package has been developed by Geneva to provide a statistical representation of themodule production and QA status, at any time and for any module production site, on thebasis of the SCT production database (also developed by Geneva). All of the SCTinstitutes use this package.

For a given module type, production period and assembly site, data are collected from thedata base for:- the noise (in electrons), noise occupancy and gain of each module chip,- the module operating temperature,- the number of defective channels found while testing the module,- the module leakage currents at 150V and 350V,- the metrology measurement parameters in all 3 dimensions.The query also generates for each module a list of tests for which the information was notentered to the database. This provides an easy way to identify missing tests or problemswith the tests uploaded to the database. A ROOT application then provides a graphicalstatistical representation, making the identification of specification errors easy. Whererelevant, the accepted specified ranges are marked on the plots. Figure 4 shows anexample of the metrology parameter display for a sample of forward outer modules, andFigure 5 shows the average module noise for all production modules built so far inGeneva.

Figure 4 : An example of the metrology parameter display for a sample of forward outermodules. Specification limits are shown in red.

9

Figure 5 : The average module noise for all production modules built so far in Geneva.

C. SCT Production Database

The SCT production data base, developed and maintained by Geneva, has operated stablyfor more than 2 years. New utilities were recently completed to allow SCT users to accessand upload data from the module production. The last important developments are thefollowing:- an extension of the data structure and implementation of the utilities to handle the

barrel module metrology survey data;- the creation of an attribute to allow external file formats (cad, doc, ppt, xls); - the creation of generic test definitions and the corresponding upload and consultation

tools, allowing uploading of any test data in a raw data mode without considering anyadditional tables or extension of the structure,

- an upgrade of the database software and hardware in mid-2003 by the DepartementInformatique of Geneva University, that consisted of a new host SUN machine, anupgrade to Oracle 9i Kernel, a latest Oracle Application server and an upgrade to theDesigner 6i (Oracle Development Tool Kit).

More than 4Gbytes space has already been used by the SCT collaboration including apart of the component data already produced and a third of the barrel modules. Theforward module production has not started yet.

D. SCT K5 module electrical and thermal performance.

Electrical Performance

During 2002, a total of eighteen prototype modules were built and extensively tested onsingle module test benches. An ATLAS note published by the group in August 2003 [2]

10

summarizes the electrical performance of all these prototype modules. Figure 6 shows themean measured noise (e- ENC) and the gain (mV/fC) of each of the 12 ASIC chips for thenon irradiated prototype end-cap modules. The average e- ENC for the outer modules (theleast favorable case in terms of noise, due to the long detector strips) is about 1430 e-.The noise occupancy values, corrected for the calibration capacitance variation and forthe temperature as explained in [2] are well below the foreseen limit of 5x10-4 and theefficiency in terms of working channels is >99%. The typical timewalk that has beenmeasured for non-irradiated modules varies between 11 and 14 ns. The non-irradiatedmodules are thus well inside the specifications.

Figure 6 : a) Average ENC noise for prototype K5 modules, correcting for calibrationfactor and normalizing to the foreseen SCT operating temperature.

b) Average module gain corrected for each module with the appropriatecalibration factor.

Seven modules were irradiated at different fluences, with a 24 GeV proton beam at theCERN PS. Four (K5 305, 308, 503, 504) were irradiated with the nominal fluence of~3x1014 protons/cm2, simulating 10 years of ATLAS operation. Two (K5 310, K5 303)were irradiated to half the dose (fluence of about 1.5x1014 protons/cm2). The remainingmodule (K5 312) underwent a full irradiation in two steps: initially to half the dose, andthen four months later to reach the total fluence [3]. The data summarized in Table 1 arecorrected both for calibration capacitor variation and for temperature, as explained in [2].

module#

gain(mV/fC)

threshold.spread@ 1fC (e- ENC)

Noisee- ENC

Occupancyx 10 - 4

303 43 460 1899 5.0310 37 480 1995 8.7312 38 530 2115 15.6305 27.6 614 2433 158308 30.5 634 2208 71.8503 29.0 655 2427 107504 27.7 697 2307 89.8

Table 1 : Electrical performance of half-irradiated (303,310,312) and fully irradiated outermodules.

11

Figure 7 shows the evolution of the e- ENC with the irradiation dose. The noise limits(red line) are reached when the modules are half-irradiated, that is after about 7 years [4]if operated at the foreseen threshold of 1 fC.

For the five fully irradiated modules under study, the noise level is around 2300 e- ENC,and the noise occupancy between 27 and 160x10-4, while the specifications are 1800 e-ENC and 5x10-4 respectively. To reach the noise occupancy level required by thespecifications, higher threshold operation will then be required with a correspondingexpected loss in tracking efficiency.

Figure 7 : Variation of the ENC noise with fluence. The red line represents thespecification limit.

Beam test

The test beam set-up is described in [5]. The tracking efficiency is measured by requiringa binary module hit < 150 µm from the position of the track as extrapolated from ananalog telescope. Efficiency vs threshold curves are reconstructed by scanning thediscriminator over a large range of values, corresponding to charges of 0.7 - 6 fC. Thenoise occupancy is counted in dedicated noise events taken with a software trigger in theout-of-spill period. Figures 8 and 9 show the efficiency around the envisaged operationalthreshold of 1 fC, and the noise occupancy on a logarithmic scale, modules before andafter irradiation. The efficiency and noise occupancy limits are indicated. Afterirradiation, the discriminator threshold needs to be increased to meet the required noiseoccupancy specification of 5x10-4, at the price of the efficiency.

12

Figure 8 : Efficiency (l.h.s. axis) and noise occupancy (r.h.s. axis) averaged over all non-irradiated modules.

Figure 9 : Efficiency (l.h.s. axis) and noise occupancy (r.h.s. axis) averaged over fullyirradiated K5 305 and K5 308.

In September 2003, a small combined test beam run was made gathering the SCT,Tile|Cal, MDT, RPC and TGC sub-systems of ATLAS. Data successfully propagatedthrough the DataFlow (ROD emulator, SFI, EB, EF, SFO) to standard ATLAS data files.Even though some elements were missing or at a preliminary stage (for example a SingleBoard Computer was used to act as a ROD emulator for the SCT) this experience was agood starting point for next year’s combined test beam.

Thermal performance

Extensive studies were performed on different cooling block concepts, and on theintrinsic thermal performance of modules, and these summarized in an ATLAS note [6].

13

The thermal runaway in particular was measured with an inner module (the most criticalthermal design because of its single cooling point) mounted on a PEEK split block [6]and cooled with a conventional liquid chiller. For this measurement, the atmospherictemperature was tuned to the surface temperature of the detectors, to reduce the heatexchange of the detectors with the environment. As shown in Figure 10, the runawaypoint is well above the specification value of 240 µW/mm2 even with the lower heattransfer coefficient of the monophase liquid coolant.

Figure 10 : Rescaled thermal runaway plot to different coolant temperatures: black dots(measured) Tcool= –5oC, stars Tcool= –15oC, white dots Tcool= –22oC.

The heat load coming from convection is estimated to increase the detector temperatureby about 2oC, thus leaving the module within the specifications. However, this resultshould be treated cautiously, as the result of a measurement on a single module.

The performance of the end-cap modules (electrical, thermal and beam test) was thecontent of a contribution to the Frontier Detectors for Frontier Physics conference [7].

E. SCT KB module electrical and thermal performance.

As a backup to the K5 module design, the Geneva, CERN and Melbourne groupsdeveloped an alternative module design. The KB module, which used the same hybrid asthat used for SCT modules in the barrel region, was shown to be electrically andmechanically satisfactory. However, because K5 hybrid prototypes operatedsatisfactorily, the SCT Collaboration rejected this option in February 2002. The Genevagroup completed the development of the KB option with the construction of 7 prototypemodules that operated well. A full discussion of the electrical, mechanical and thermalperformance of these modules is given in [1]. Since February 2003, two ATLAS noteshave been published by the group [8, 9] and a final NIM publication is in preparation.

F. SCT Barrel Mechanics

The production of the four cylinders (B3-B6) of the barrel SCT support is complete, andall barrels have been delivered to the University of Geneva. The smallest barrel has been

14

fully equipped with brackets for the module support (Figures 11 and 12) and has beentransported to the Rutherford Appleton Laboratory (RAL) where cooling units andelectrical harnesses are being added. In the near future, the barrel will be transported toOxford University where barrel modules will be assembled on to the barrel. Theremaining barrels (B4-B6) remain in Geneva until the completion of work on B3 at RAL.Barrel B6 is ready for transport to RAL, and furbishing of the remaining barrels isnearing completion (Figure 13).

Figure 11. Exploded view of bracket components mounted on the barrel cylinders

Figure 12 : Photograph barrel 3, fully equipped with brackets.

15

Figure 13 : Photograph of the SCT barrel support structure during QA of the assemblyprocedure (barrels B4-B5+B6).

G. SCT Integration

At the time of the submitted research plan, the SCT schedule planned the first assembledbarrel at CERN in April 2003, with the remaining assembled barrels arriving beforeNovember 2003. This schedule is now being re-evaluated. The first barrel will not reachCERN before April 2004.

The Geneva group will take an active part in the development of the detector controlsystem (DCS). The safe operation of the detector at all test stages and in the finalexperiment is crucial because of its cost and fragility. The SCT DCS project issubdivided into 4 interconnected parts: the CIC (central infrastructure control) project,the MOPS (modules and power supplies) project, the SCT cooling project and theenvironmental DCS project. The latter is a Geneva responsibility. It consists ofmonitoring the temperature at key locations along the cooling pipes on all the barrels andendcap disks, as well as on the support structure and the thermal enclosure. The humidityand pressure must also be monitored within the thermal enclosure. Moreover, actionshave to be taken in case of abnormal conditions and appropriate warnings and alarms beissued. A detailed failure analysis is therefore required. In case of warnings the operatorsmay be allowed to take manual actions, but alarms will lead to automatic reactions of theDCS system through a hard-wired interlock matrix.

Figure 14 represents a simplified schematic drawing of the first stage of theenvironmental DCS project. A first version of the project must be prepared before thearrival of the first barrel at CERN. Temperature (NTC), humidity (h) and pressure (p)sensors will have to be monitored via modules called ELMBs. The same information willbe fed into an interlock box (IBOX), which will send over-threshold signals to theinterlock matrix resulting in a certain reaction on the power supplies of the SCT modules.

16

Due to the entanglement of the different DCS projects and the various testing stages(single barrel acceptance tests, full barrel tests, endcap acceptance tests and inner detectorintegration), modularity and flexibility of the environmental DCS project will represent amajor concern from the conception of the project and throughout its development.

Figure 14 : Schematic drawing of the SCT DCS project with emphasis in the environmentalDCS project.

Finally, mechanical preparations are being made in Geneva for the assembly of the 4SCT barrels together, and for the assembly of the full barrel SCT into the Inner Detectorvolume (Figure 15)

Figure 15 : Schematic of the assembly tooling for the 4 SCT barrels.

A.1.2. The Liquid Argon Calorimeter Readout

Since the report in February 2003 [1], activities have concentrated on testing the ReadOutDriver (ROD) board prototypes for the Liquid Argon (LAr) calorimeters. The board, anessential part of the calorimeter readout system, is responsible for calculating the energy

17

and the time relative to the peak of the signal for each of the calorimeter cells. It consistsof a mother board and four mezzanine boards called Processing Unit (PU) boards.Geneva is responsible for the ROD mother boards of all LAr calorimeters, i.e.approximately 200 boards. A good description of the full system can be found in [10].

Four prototype ROD mother boards were built in 2003. Figure 16 shows the current RODmother board prototype. It also shows the water cooling system for the Glink chips(under the copper plate on the figure). Four dummy PUs (shown in Figure 17) and adeserializer board have also been designed and built by Geneva to test the complete RODmother board including all possible data paths. Using an extra board that includes theVME interface, the quality of the full data transfer through the board could be tested.

Figure 16 : Picture of the ROD mother board prototype in the University of Geneva

Neither bad connections nor short circuits were found in the board. The list of testsincludes:

- test of the input optical links by using a tester board, borrowed by SMU (USA);- test of the performance of the water cooling using different glues with the temperature

of each Glink chip read through VME;- test of all data paths including the staging path (possibility of running the ROD board

with only two PUs instead of four);- test of the VME chip and the interrupts with the new VME CPU;- test of the Trigger Timing and Control FPGA (Field Programmable Gate Array);- test of the ROD mother board together with the final PU, built by LAPP-Annecy

(France);- test of the transition module (built by Paris-Orsay, France) together with the ROD

mother board;- finalisation of the output controller FPGA software program.

18

Figure 17 : Picture of the dummy Processing Unit board.

Since the hadronic tile calorimeter group of ATLAS decided to use the same ROD boardfor reading out their data, a collaboration between Valencia (Spain) and the University ofGeneva developed during 2003. Involvement of the University of Geneva includes testsof the Glink chips at 40 MHz (a 80 MHz clock is used by the LAr calorimeters),implementation of specific tasks in the FPGA chip that receives the data in the RODmother board, and help in the VME interface implementation.

Using the common ATLAS-LAr online software, different programs have beendeveloped and written in order to test the ROD boards. Figure 18 shows the graphicaluser interface of one of the mostly commonly used programs. This program provides thefull functionality needed to test the complete board including all data paths.

Figure 18 : Graphical User Interface of the test program of the ROD board developed andused in the University of Geneva.

A complete ROD crate test (with 14 ROD boards and other modules such as thetransition modules) was foreseen in 2003 together with other crates before launching theproduction of the full ROD system. Due to financial constraints, only 5 ROD boards willbe used for this test. The test also includes the trigger timing and control, the front-endand the data acquisition readout systems. Thus this will be a significant but incomplete

19

test of the full system with all interfaces working together. This test is foreseen to takeplace between November 2003 and February 2004 at CERN. For this reason, aproduction of three new ROD mother boards slightly modified with respect to the currentprototype is ongoing. No big changes have been implemented apart from the addition oftwo drivers of the JTAG chain and the type of fuse.

Two different beam tests are foreseen for the liquid argon calorimeters in 2004: oneincluding a full LAr end-cap, and another one with the barrel liquid argon calorimetertogether with the tile calorimeter and other detectors. The final ROD boards will be usedto read out all test beam data. This will also help testing the RODs together with thetrigger. The complete production of 200 boards will be launched in 2004, after asuccessful ROD crate test and test beam data taking. The first modules ready to beinstalled in ATLAS are expected end of 2004. No cost over-runs are expected.

A.1.3. ATLAS Physics and Simulation Activities

Fast Simulation of the ATLAS Liquid Argon Calorimeter

Simulation of physics events in the ATLAS detector is performed using the GEANT4simulation package [11] in a complete object oriented (OO) C++ environment. Recentcomparisons [12] between GEANT4 simulation and ATLAS test-beam results show verygood agreement. This is due to the more detailed modelling of the physics processes withrespect to the previously used GEANT3 package. However, more computing time (CPUtime) is spent in the event simulation process, especially for electromagnetic showers inthe ATLAS Liquid Argon (LAr) calorimeter. Therefore, the activities of our groupconcentrate on improving the timing performance of the simulation. The detailed showermodelling is replaced by a faster algorithm that reproduces the shower shape and energydeposition in the calorimeter. The GEANT4 software already provides a tool that triggersthe fast simulation model in user-defined detector volumes. In this way, fast simulation isapplied only for pre-defined sub-detectors, like the LAr calorimeter, while the simulationfor other sub-detectors is still performed in full detail.

A first fast simulation prototype [13] of a lead-LAr sampling calorimeter wassuccessfully implemented in GEANT4. In this prototype, a simple geometrical structureof parallel lead plates with Liquid Argon gaps was chosen. The showers in the samplingstructure produced by electrons of different energies were simulated. The longitudinaland radial shape of the electromagnetic showers was parameterised in such a way that theshape agrees with the full GEANT4 simulation. The parameterisation followed thedescription of Reference [14], which gives parameterised formulae for average showershapes. A typical Gamma-function is used for the longitudinal part. The lateral shape isdescribed by a fraction of polynomials, separating core and tail of the radial shower.Fluctuations and correlations of the parameters are taken into account in a consistent way.Good agreement between the fast and full simulation was measured [13]. However, thisparameterisation was not found to be adequate for the more complicated geometricalstructure of the LAr calorimeter of ATLAS. A barrel segment of the LAr barrelcalorimeter (M0 module), shown in Figure 19, as used in a test-beam setup [15] is

20

simulated. In ATLAS the lead absorber plates have an accordion shape interleaved withliquid Argon gaps. Due to this, the lateral shower shape is significantly different fromshowers in parallel-plate geometry. After a long study, an appropriate parameterisationwas found using a pair of Gamma-functions also for the radial shower shape. As it can beseen in Figure 20, the fast shower algorithm nicely reproduces the detailed GEANT4 test-beam simulation. Good results are found for different energy ranges (1-100 GeV) andangular ranges (η from 0 to 0.8).

The time spent in simulating one electron shower scales with energy. In full simulationmode it is proportional to the number particles in the shower that are needed to betracked. The scaling applies also to the fast shower model because the number of singleenergy depositions is also proportional to the incident electron energy. The gain in CPUtime therefore depends on the energy of the electron entering the LAr volume. The gainin speed is about a factor of 10 at 1 GeV and about a factor of 50 at 1TeV. Here, only thesimulation time of the LAr calorimeter is taken into account.

Currently, work is in progress to implement the fast shower model in the softwarepackage ATHENA, which is the OO/C++ framework for the complete simulation of theATLAS detector. Studies involving the full ATLAS geometry are important to verify thegain in computing time as well as the shower description. It is planned that these studieswill be part of the next ATLAS data challenge (DC2) that is foreseen for spring 2004.

Figure 19 : Barrel module of the ATLAS electromagnetic calorimeter

21

0 100 200 300 400 500

0

10

20

30

Longitudinal Profile

Shower Depth d/mm

Figure 20 : Longitudinal shower profile of 10 GeV electrons in the LAr calorimeter. Thedots with error bars represent the result of the full simulation. It is compared tothe fast shower simulation, shown as a histogram

Measuring the top quark mass in ATLAS

A sample of 500,000 fully simulated tt events is now being produced (S. Moëd). Thesample will be used for the reconstruction of the top quark mass. A reconstruction of thetop mass with ATLAS simulated events has been done already using 'smeared' events andis reported in the ATLAS TDR, a later study using fully simulated DC1 events waspresented in a scientific draft note.

However the simulation for the current study includes a full η coverage that did notpreviously exist and in addition the ATLAS reconstruction tools and options haveimproved. The goals of this analysis are:- an improvement of the former analyses;- an evaluation and testing of software, using the LHC computiong facilities at CSCS

Manno;- an understanding of the impact of jet algorithms and jet energy scale on the analysis;

and- most importantly, the testing and subsequent improvement the b-tagging efficiency.

Looking at the decay chain tt → W+bW−b → qqb l−νb, the lνb decay is tagged using ahigh-pT lepton and b-tag on one jet, leaving an unbiased sample of 3-jet qq bconfigurations for which the b-jet can be identified kinematically. It allows a largesample of both b and light quark jets to be isolated and provides a good environment tostudy the performance of the b-tagging algorithm.

22

Heavy Ion Collisions

The feasibility study of using the ATLAS detector with heavy-ion beams at 5.5A TeVcollision energy has continued (L. Rosselet). Both jet quenching and dissociation ofheavy flavour bosons, which are very promising signatures of a quark-gluon plasma(QGP) formation, seem to be accessible in ATLAS. The possibility of observingquarkonia production via their decay in µ’s, and, hence, their expected suppression by aQGP formation, is also being studied. The idea is that color screening effect in QGPprevents the various Ψ,Υ and χ states to be formed when the color screening lengthbecomes smaller than the size of the resonances, allowing this way to probe the nuclearpotential. We first focused on the Υ study in Pb+Pb collisions. As previously reported,the stand-alone µ-system gives insufficient mass resolution (460 MeV) to separate the Υstates. An algorithm has been developed to match µ candidates to tracks in the innerdetector. It uses combined information from the SCT and PIXEL detectors, and from theµ-spectrometer, but not from the TRT because its large occupancy in heavy-ion collisionsmakes it unusable. The matching is done by selection on the χ2 of a global track fitbetween the different detectors, keeping the best combinations. A χ2 cut and geometrycuts are applied after back-extrapolation to the vertex. The optimization has been done bycomparison of a sample of Υ events with a sample of HIJING [16] events used asbackground, after full processing through GEANT and the standard ATLASreconstruction package. The large µ-background coming from π and K in-flight decaysbefore the calorimeter is suppressed both by a 3 GeV minimum pT cut and the χ2 cut ofthe matching algorithm. The mass resolution, which ranges from 110 MeV to 150 MeVdepending on the pseudo-rapidity η of the decay µ’s, is improved. A maximum η cutapplied on the µ’s reduces the resolution but also the acceptance, and a compromisebetween acceptance and resolution has to be found to clearly separate Υ states withmaximum statistics. Typically, limiting the acceptance to the barrel only (|η|<1) wouldprovide a resolution of 126 MeV, sufficient to separate Υ and Υ’ states (Figure 21), witha combined acceptance and efficiency of 8.7%.

Figure 21 : ΥΥΥΥ and ΥΥΥΥ’ invariant mass showing the separation between ΥΥΥΥ and ΥΥΥΥ’ for thebarrel alone.

23

The signal/background ratio is 2.0 and the purity of the signal, without taking intoaccount the Υ’ contamination, is in the 94-99% range depending on the cuts. The numberof Υ → µ+µ−accumulated in one month of Pb+Pb running is expected to be 2x104, whichshould allow the study of the Υ state for different centrality values of the collision.

A di-muon trigger using a µ pT cut in the 3-4 GeV range is being investigated. A J/Ψstudy is also under way.

A.2. The CDF Experiment

The upgraded CDF detector has been accumulating physics quality data since February2002. The data sample accumulated on tape is 270 pb-1, of which about 200 pb-1 is ofgood quality, roughly twice that of Run1. A full data analyses program is well underway.Fermilab has established a realistic Tevatron operational plan, aiming for doubling thedata each year for the next two years, giving CDF close to 1 fb-1 by the end of 2005. Thisis roughly one order of magnitude more data than Run1.

The upgraded CDF detector is functioning very well. All detector sub-systems, includingthe delicate silicon tracking system, are in stable running condition. Offline software,calibration and detector alignment have reached a mature stage, making high qualityphysics analyses possible. Preliminary results using CDF run II data have already beenpresented at international conferences, among which are some interesting new results incharm and B physics that were made possible by the Silicon Vertex Trigger (SVT), ofwhich Geneva has made an important contribution. Currently a final reprocessing of thefull data sample is on-going and is expected to be completed by December 2003.

The Geneva group continues to carry out its duty of maintenance of the SVT. Severaltrigger implementations for B physics and Exotic physics groups have been made, andare continuously being monitored and tuned for increasing machine luminosity. SeveralRun II analyses in charm physics, rare B decays and QCD physics are in good progress.

A.2.1 SVT

The Silicon Vertex Tracker (SVT) is a hardware level-2 trigger system that reconstructscharged tracks with a precise impact parameter to identify those from a secondary vertex,such as the B-hadron decay vertex. The Geneva group built the Associative MemorySequencer (AMS) of SVT and is responsible for its operation through Run II. This deviceis a major innovation in hadron collider detector technology. It has opened up the wholenew field of hadronique c-quark and b-quark physics at hadron colliders, and it will alsocontribute to the measurement of the top quark mass and the search for new particles.

The AMS boards works very well due to their robust design. In the past year no failurehas occurred. However we are keeping a test stand in working condition in Geneva inorder to be ready for any necessary repairs (Y. Liu, M. Campanelli). Besides being

24

responsible for the AMS boards, the group is also actively involved with the operation ofthe SVT and the study of its performance (M. Campanelli, X. Wu).

A.2.2 Physics trigger implementations

Due to an overwhelming QCD background, it is vital at a hadron collider to deviseappropriate triggers for various interesting event signatures. Exploiting the triggercapabilities of the SVT, the group (X. Wu) has designed, implemented and verifiedseveral physics triggers that utilize information from SVT. This substantially enhancesthe physics reach of data analyses at CDF.

- Rare B dimuon triggers [17]. Five complementary triggers paths have beenimplemented to collect low mass di-muon events covering various muon detectors anddifferent kinematic regions. This trigger is sensitive to any rare B decays having twomuons in the final state. Since the di-muon trigger rate is dominated by background offake muon pairs of low mass, by making cuts on the SVT impact parameter rather thana low mass cut it is possible to preserve signals in the low mass region (~1 GeV) whichis important for new physics searches.This trigger is fully functional and has collected adata sample that is being used in the rare B analysis of A. Zsenei.

- Inclusive high pT b-jet trigger [18]. This trigger is devised to be an inclusive high pT b-jet trigger, made possible for the first time at a hadron collider by SVT. This datasample can be used in multitude of studies such as QCD studies and search for newparticles decaying to final states containing b-quark, such as Higgs and SUSY particles.This trigger is also fully functional. This trigger has collected a large data sampleenriched in b-quarks. Studies are underway (S. Vellecorsa, X. Wu) to understand thecomposition of this data sample and to develop first sets of analysis using this datasample.

- Photon+b-jet trigger. Some new physics processes predicted events containing isolatedphotons and high pT b-jets, such as some SUSY models with the Gauge MediatedSUSY Breaking (GMSB) mechanism. We have implemented a trigger for such events,using SVT at level 2 to identify b-jets. This data sample is also useful for importantQCD studies of photon plus c-quark and photon plus b-quark production. Using SVTallows the photon ET threshold to be lowered, otherwise impossible because hightrigger rates. This trigger has also been collecting data. An analysis to use sample tostudy photon plus b-quark is planned.

These triggers are continuously being monitored and tuned for increasing machineluminosity (X. Wu). The latest modification was the addition of the requirement ofconfirming SVT tracks with level-3 silicon tracks. One of us (X. Wu) continues to servesas the co-convener of the Exotic Trigger/dataset subgroup.

25

A.2.3. Run 2 data analyses

The group’s Run 2 analyses have evolved from its Run 1 experience, and has profitedfrom its deep involvement in the SVT hardware and SVT-related trigger implementation.Since the last report, the group has made significant progress in Run 2 data analyses.Several analyses are at the final stage, with preliminary results qualified by theCollaboration to be shown at conferences. As new students join the group, new analyseshave also been started or are being investigated. Our current lines of analysis are: QCDdiphoton production, excited charm states, rare B decays and b-quark production usingvertex tagging.

Photon analysis.

The group’s interest in photon analyses originated from its development of the photon+b-jet trigger. In the past year the group continued to made important contributions to thephoton analysis, including dataset validation, trigger efficiency studies and the calibrationof the Central Shower-Max detectors (CES). Y. Liu has been the responsible person forthe photon dataset validation, as well as the librarian of the CES simulation software. Histhesis subject is the measurement of the di-photon cross section; a comparison of the di-photon cross section with QCD predictions is very topical since it is sensitive to higherorder effects and previously measured cross sections showed some discrepancies withtheoretical predictions. The 4-momentum of particles in the di-photon final state can beprecisely determined due to the fine resolution of EM calorimeter. The imbalance in thetransverse momentum of the two photons provides a clear probe of the transversemomentum of the colliding partons. At collider energies, most of the transversemomentum of the incoming partons can be attributed to multiple soft gluon emissionsprior to the collision, of which the effect to di-photon production can be resummed by theCollins-Soper-Sterman (CSS) formalism. The Tevatron is a good laboratory for makingprecision comparison to di-photon data. This subject is also interesting for the LHCbecause it is the irreducible background of the H→γγ signal.

Di-photons are selected from the 12 GeV isolated diphoton trigger from a data sample of108 pb-1. The basic offline photon cuts are: central (|η|< 0.9), ET>13 GeV, isolated(energy in a cone 0.4 around the photon < 1GeV), shower-max detector (CES) profilecompatible with an electromagnetic shower. In total 573 diphoton candidates areselected, a large fraction of which are background events coming from 0π decays. Themain difficulty of the analysis is the background estimation. For photons with ET < 35GeV, a method using the shower shape information obtained with the CES developed inRun 1 was adapted. The constants are recalibrated with η→γγ events and checked with Wand Z electrons. For higher energy photons, a method using the pre-shower detector(CPR) is used. After background subtraction, 256 ± 44 events out of the 573 candidatesare estimated as diphoton events.

After trigger, acceptance and efficiency correction, the preliminary di-photon crosssection as function of the di-photon mass is shown in Figure 22, where predictions fromLO and NLO calculations (DIPHOX [19]) are superimposed. The invariant mass

26

distribution is very well predicted by the calculation. However, some deviation at the lowend of the di-photon system pT (commonly called qT) distribution between data and theDIPHOX prediction is noticed (Figure 23), which is because the effect of soft gluonradiation at initial state is not included in the DIPHOX calculation, while ResBos, aprogram that re-sums the soft gluons, is able to describe the qT distribution pretty well.

This preliminary result [20] has passed a review by the collaboration for presentation atpublic conferences. The plan is to extend the analysis to include the full data sample(~200 pb-1) and prepare a publication before Summer 2004.

Figure 22 : The measured di-photon cross section as a function of the di-photon mass. Thesmaller error bars indicate statistical errors only, the larger error bars indicatestatistical and systemic errors added in quadrature.

Figure 23 : The measured di-photon cross section as a function of the qT. The histogram(green) is from the ResBos NLO calculation.

27

Rare B studies.

The study of rare B decays with dimuon final states is one of the strong points of hadroncolliders compared to the B factories. The clean final states allow to trigger and select therelevant events out of the overwhelming background, making it possible to take fulladvantage of the much larger b-quark production cross section at hadron colliders. Asmentioned above, a set of rare B triggers designed explicitly for rare B decays has beendeveloped by the Geneva Group. A first study being carried out is on the decay of

*0 KBd−+→ µµ .

The analysis (A. Zsenei) is at the point of being completed. The analysis starts with a pre-selection in order to reduce the dataset size to a manageable level. That is followed by thebaseline selection where the pre-selection cuts are refined in order to eliminate the mostobvious backgrounds while maintaining very high efficiency. Then, an optimization isperformed on three variables considered to have the strongest background rejectionpower. These are the transverse decay length, the pointing angle and the isolation. Thefirst one is a strong rejection criterion, because the lifetime of B mesons is relativelylong, while the background is mostly short-lived. The pointing angle is the angle betweenthe momentum of the B meson and its flight path in the transverse plane, and is anotherstrong discriminating variable. The isolation measures the fraction of the momentumcarried by the daughters of the B meson in a local region around the B. This fractionshould be large, and as it is hard to model with Monte Carlo simulations data must beused to derive the efficiency. In order to do that, **0 KKJBd

−+→Ψ→ µµ has beenchosen as the reference decay (Figure 24).

All the efficiencies, except for that of the transverse decay length, the pointing angle andthe isolation, were derived from the *0 KBd

−+→ µµ Monte Carlo. The MC simulationwas checked for quality by comparing the distributions of relevant variables from MCand from the data. The three optimization variables were checked for correlations in orderto be able to perform the optimization on samples with higher statistical significance. Asexpected, the transverse decay length and the pointing angle were found to be correlated,but not the other variables. In the optimization procedure the *0 KJBd Ψ→ signal isextracted from the dimuon mass region around the ΨJ mass, while the background isderived from the fitted background shape from the two sidebands around the B mass(excluding the ΨJ and ψ(2S) resonances.

As the time of this report the optimization is almost complete and the box containing thesignal region is ready to be opened. Because of the limited data sample size, only a limit,or an observation of low significance is expected.

28

Figure 24 : The reference *KJBd ΨΨΨΨ→→→→0 peak after baseline selection.

Charm Physics.

The group’s study of orbitally-excited charm mesons is at an advanced stage (M.Campanelli). This analysis uses a data sample of heavy flavor hadronic decays triggeredby the SVT.

The total angular momentum of a meson is the vector sum of the spin of the two quarksand their relative angular momentum. In the case of mesons with one heavy quark, if wedefine sQ and sq the spin of the heavy and light quark, respectively, it will be

qs L �

�

�

�

++= QsJ , with L �

the angular momentum. In the limit of ∞→Qm the meson mass

only depends on L �

�

�

+= qq sj , and the two orbitally-excited 1L = doublets ( *1D , *

0D ) and

( *2D , 1D ) would be degenerate in mass. The hyperfine splitting due to the finite charm

mass introduces a small mass difference, especially interesting to study for the 3/2jq =

states, the doublets ( D*2 , 1D ), whose suppressed D-wave leads to width of about 20

MeV, for a mass splitting of about 40 MeV. Those two channels decay in the same finalstate: +−++−++ →→→ πππ KDDDDD sd

00 ,* ,*** (where **D represents D*

2 and 1D ), but the two different helicity states lead to decay distributions in the angleα between the slow pion sπ and decay pion dπ in the +*D rest frame. For pure D-wave,

1D decays are distributed as α2cos 31+ , while D*2 decays as α2sin .

Those states are observable in CDF thanks to the SVT trigger for hadronic b decays. Wesearch for a 0D among the displaced tracks that triggered the SVT, then for a ±*Drequiring the small difference in invariant mass between the three-body and the two-bodysystem. Finally, another pion of opposite charge is associated to the charged *D , tocreate a neutral **D system. To get a better resolution, we plot in Figure 25 the massdifference between the **D and the *D , where both peaks from the 1D and the D*

2

can be seen.

29

To exploit the knowledge of the different decay behavior of the two states, we perform anunbinned likelihood fit using as input the mass difference and the helicity distribution.The two mass peaks are fitted with a Breit-Wigner function convoluted with a gaussian totake into account the resolution of the apparatus. The background is described by a 4-parameter function, plus a possible contribution from the broad states, described as anadditional broad resonance, The statistical significance of this measurement is a factor 2better than present PDG average, and evaluation of systematic errors is presently understudy.

Figure 25 : Mass difference between the **D and the *D system.

Inclusive b-quark production cross section.

Measurements of the b-quark production cross section at pp colliders provide animportant quantitative test of QCD. The mass of the b-quark is considered large enoughto justify perturbative expansions in the strong coupling constant sα . Consequently dataon b-quark production are expected to be adequately described by calculations at thenext-to-leading order (NLO) in sα . Past measurements of inclusive b-quark productionwere done by CDF at Run 1 using exclusive +B decays and the result indicated an excesswith respect to the NLO QCD predictions. A critical reanalysis of the theoreticalprediction gives today a discrepancy of Data/Theory = 1.7±0.5(theo) ±0.5(exp.), less thanwhat it was until two years ago (~ 3). The reduction in the discrepancy comes fromimproved knowledge in various areas, among which the fragmentetion process of goingfrom a perturbative b quark to a B hadron.

The group (M. D’Onofrio) has taken on the responsibility to perform a measurement ofthe inclusive b-quark production cross section using jets, which will extend the upperreach of the measurement using exclusive decays in order to explore the behavior at highpT. In addition, corrections on fragmentation and decay to which the theory is subject toare probably smaller with jets than with exclusive decays.

30

The analysis uses the good tracking capabilities of the CDF detector to tag b-jets byreconstructing secondary vertices. The algorithm (SECVTX) uses displaced tracksassociated with jets if they are within a cone of 0.4 in the η-ϕ space of jet axis. Thesearch for secondary vertices is defined in two steps (or pass) with selection based on thesignificance of the impact parameter and of the decay length Lxy. Only jets withtransverse energy more than 10 GeV and |η|< 2 are considered by the SECVTX: amongthem, a tagged jet is defined as positive tagged if the distance Lxy between the primaryand secondary vertex is more than 0, negative tagged if Lxy <0.

A MonteCarlo study has been made to understand the problems of the analysis and tovalidate the b-tagging capability, related to the signal and background, of the SECVTXalgorithm. Preliminary studies show that in a general QCD Monte Carlo (Pythia with PT

cut on both partons from hard scattering varying from 18 GeV to 40 GeV) there is a 2.5%of events with at least 1 b-jet taggable (acceptance limit of SECVTX, 2 good tracks in thejet subcone of 0.4). A 5% is instead associated with c-jets, which, together withmistagged jets, constitutes the main source of background. The MC study has beenfocalized in the evaluation of tagging efficiency (Figure 26a) and in searching for goodvariables to discriminate b-jets, c-jets and light quark-jets. Figure 26b shows that amongpositive tagged jets only a fraction of 60% is associated with b quark, while the rest isshared between c-jets and light quark jets. Figure 27 shows that the invariant mass of alltracks used by the algorithm to construct a secondary vertex in the jet, so called "tagmass", is clearly a good discriminating variable useful to determine the samplecomposition of jet data. A comparison with inclusive jets from the jet data sample isunder way. First preliminary results on inclusive b-jet cross section are foreseen forwinter-summer conferences 2004.

Figure 26 : a) (left) Tagging efficiency for b-jets (green), c-jets (red) and light-quark jets(blue).

b) (right) Fraction of b-jet(green), c-jet(red) and light-quark jets (blue) inpositive-tagged jets.

31

Figure 27 : Distributions of tag-mass for b-jets (green), c-jets (red) and light-quark jets(blue) for hard scattering pt cut of 18 GeV (left) and 40 GeV (right).

As mentioned previously, since November 1 2001 A.-S. Nicollerat from ETHZ hasjoined the group as a visitor to work on luminosity measurements using forward Wevents. Since October 2003, two other students and one senior physicist from ETH (A.Lister, J. Ehlers and G. Dissertori) have also joined the group to participate in CDF dataanalysis.

32

References

[1] A. Clark et al., Scientific Report for the years 2000-2002 and prospective plans,February 2003.

[2] M. Mangin-Brinet et al., Electrical test results from ATLAS-SCT end-capmodules, ATL-INDET-2003-008.

[3] P.J. Dervan et al, Irradiation of ATLAS SCT Modules and Detectors in 2002.[4] ATLAS Inner Detector Technical Design Report, Vol II, CERN/LHCC 97-17.[5] Beam tests of ATLAS SCT Modules, ATL-INDET note in preparation[6] M. Donega et al., Thermal performance of the ATLAS-SCT forward modules,

ATL-INDET-2003-010[7] M. Mangin-Brinet et al, ATLAS-SCT End-cap module performance and status of

production, Nucl. Instr. Methods, to be published.[8] M. D'Onofrio et al, Electrical performance of ATLAS-SCT KB end-cap modules

ATL-INDET-2003-007; Geneva : CERN, 20 May 2003 . - 16 p[9] M. Donega et al, Thermal performance measurements on ATLAS-SCT KB

forward modules, ATL-INDET-2003-008; Geneva : CERN, 16 May 2003 . - 21 p[10] A. Blondel et al, The ATLAS Liquid Argon calorimeters Readout system,

Proceedings of the IEEE Nuclear Science Symposium conference in Portland(USA), October 2003.

[11] S. Agostinelli et al., GEANT4 – A Simulation Toolkit, Nuclear Instruments andMethods A 506 (2003) 250.

[12] A. Dell’Acqua, Status of the Physics Validation Studies Using GEANT4 inATLAS, CHEP-2003-MOMT003, June 2003.

[13] F. Mazzucato, First study on the integration of a fast shower parameterization inGEANT4, ATL-COM-PHYS-2003-005.

[14] G. Grindhammer et al., The Fast Simulation of Electromagnetic and HadronicShowers, Nuclear Instruments and Methods A 290 (1990) 469;G. Grindhammer et al., The Parameterised Simulation of ElectromagneticShowers in Homogeneous and Sampling Calorimeters, hep-ex/0001020..

[15] B. Aubert et al., Performance of the ATLAS Electromagnetic Calorimeter BarrelModule 0, Nuclear Instruments and Methods A 500 (2003) 202.

[16] ref 4 of last year report (heavy ions)[17] Allan Clark, Xin Wu, Andras Zsenei, Run II Dimuon Trigger for Rare B Decays,

CDF Internal Note 5635, May 16, 2001.[18] Allan Clark, Xin Wu, High pT b-jet Trigger for Run II, CDF Internal Note 4901,

February 26, 1999.[19] Yanwen Liu, Xin Wu, Di-photon Central-Central cross-section measurement at

CDF Run II, CDF Internal Note 6312, September 22, 2003.[20] T. Binoth, J-Ph. Guillet, E. Pilon, M. Werlen, A full nest-to-leading order study of

photon pair production in hadronic collisions, Eur.Phys.J C16, 311-330(2000)

33

b) The following articles have been published since our last report

HIGH-ENERGY INTERACTIONS : CDF AT THE TEVATRON ANDATLAS AT THE CERN LHC

1. Search for Lepton Flavor Violating Decays of a Heavy Neutral Particle in ppCollisions at s = 1.8 TeVD. Acosta et al., The CDF Collaboration, Phys. Rev. Lett. 91, 171602 (2003).

2. Central Pseudorapidity Gaps in Events with a Leading Antiproton at theFermilab Tevatron pp ColliderD. Acosta et al., The CDF Collaboration, Phys. Rev. Lett. 91, 011802 (2003).

3. Momentum Distribution of Charged Particles in Jets in Dijet Events inpp Collisions at s = 1.8 TeV and Comparisons to Perturbative QCD

PredictionsD. Acosta et al., The CDF Collaboration, Phys. Rev. D68, 012003 (2003).

4. Search for Supersymmetric Partner of the Top Quark in Dilepton Events frompp Collisions at s = 1.8 TeV

D. Acosta, The CDF Collaboration, Phys. Rev. Lett. 90, 251801 (2003)

5. Search for Associated Production of ΥΥΥΥ and Vector Boson in pp Collisions ats = 1.8 TeV

D. Acosta et al., The CDF Collaboration, Phys. Rev. Lett. 90, 221803 (2003).

6. Search for Long-lived Charged Massive Particles in pp Collisions at s = 1.8TeVD. Acosta et al., The CDF Collaboration, Phys. Rev. Lett. 90, 131801 (2003).

7. Search for W' Boson Decaying to a Top and Bottom Quark Pair in 1.8 TeVpp Collisions

D. Acosta et al., The CDF Collaboration, Phys. Rev. Lett. 90, 081802 (2003).

8. Limits on Extra Dimensions and New Particle Production in the ExclusivePhoton and Missing Energy Signature in pp Collisions at s = 1.8 TeVD. Acosta et al., The CDF Collaboration, Phys. Rev. Lett. 89, 281801 (2002)

34

9. Search for Radiative b-Hadron Decays in pp Collisions at s = 1.8 TeVD. Acosta et al., The CDF Collaboration, Phys. Rev. D66, 112002 (2002)

10. Cross Section for Forward ψψψψ/J Production in pp Collisions at s = 1.8 TeVD. Acosta et al., The CDF Collaboration, Phys. Rev. D66, 092001 (2002)

11. Measurement of the Ratio of b Quark Production Cross Sections in ppCollisions at s = 630 GeV and s = 1800 GeVD. Acosta et al., The CDF Collaboration, Phys. Rev. D66, 032002 (2002)

12. A Study of −−−−++++ππππππππψψψψ→→→→ 0(*)0 K/JB Decays with the Collider Detector at FermilabT. Affolder et al., The CDF Collaboration, Phys. Rev. Lett. 071801 (2002)