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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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G. Bassompierre,
G. Bologna,
D. Boget,
M. Chevallier,
S. Costa,
J. Dufournaud,
M. Farizon,
B. Farizon-Mazuy,
A. Feliciello,
M. J. Gaillard,
R. Garfagnini,
R. Genre,
M. Gouanère,
B. Ille,
R. Kirsch,
P. Lautesse,
M. Richard,
E. Rossetto,
D. Sillou,
M. Spighel
[show abstract]
[hide abstract]
ABSTRACT: We give upper bounds on the photoproduction in overcritical electric fields of a neutral light boson which could explain the correlated e+e- production seen at GSI-Darmstadt in heavy-ion-atom collisions.
EPL (Europhysics Letters) 07/2007; 22(4):239. · 2.17 Impact Factor
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O. Samoylov,
D. Naumov,
V. Cavasinni,
P. Astier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
M. Banner, G. Bassompierre,
K. Benslama, [......],
T. Vinogradova,
F.V. Weber,
T. Weisse,
F.F. Wilson,
L.J. Winton,
B.D. Yabsley,
H. Zaccone,
K. Zuber,
P. Zuccon,
The Nomad Collaboration
[show abstract]
[hide abstract]
ABSTRACT: A search for exotic Θ+ baryon via Θ+→p+K0
S decay mode in the NOMAD νμN data is reported. The special background generation procedure was developed. The proton identification criteria are tuned
to maximize the sensitivity to the Θ+ signal as a function of xF which allows to study the Θ+ production mechanism. We do not observe any evidence for the Θ+ state in the NOMAD data. We provide an upper limit on Θ+ production rate at 90% CL as 2.13×10-3 per neutrino interaction.
European Physical Journal C 12/2006; 49(2):499-510. · 3.63 Impact Factor
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P. Astier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
M. Banner, G. Bassompierre,
K. Benslama,
N. Besson,
I. Bird,
B. Blumenfeld,
F. Bobisut,
J. Bouchez
[show abstract]
[hide abstract]
ABSTRACT: We present the results of a search for νμ→νe oscillations in the NOMAD experiment at CERN. The experiment looked for the appearance of νe in a predominantly νμ wide-band neutrino beam at the CERN SPS. No evidence for oscillations was found. The 90% confidence limits obtained are Δm2
Physics Letters B - PHYS LETT B. 01/2003; 570(1):19-31.
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P. Astier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
M Banner, G Bassompierre,
K. Benslama,
N Besson,
I. Bird,
B Blumenfeld, [......],
H. Degaudenzi,
T Del Prete,
A. De Santo,
T Dignan,
L Di Lella,
E do Couto e Silva,
J Dumarchez,
M. Ellis,
T Fazio,
R Ferrari
[show abstract]
[hide abstract]
ABSTRACT: A search was made among charged current events collected in the NOMAD experiment for the reaction: +N ! +D + hadrons ,! D A high purity D sample composed of 35 events was extracted. The D yield in charged current interactions was measured to be T = (0:79 Sigma 0:17(stat:) Sigma 0:10(syst:))%. The mean fraction of the hadronic jet energy taken by the D is 0:67 Sigma 0:02(stat) Sigma 0:02(syst:). The distributions of the fragmentation variables z, and x F for D are also presented.
02/2002;
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P. Astier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
M Banner, G Bassompierre,
K. Benslama,
N Besson,
I. Bird,
B Blumenfeld, [......],
H. Degaudenzi,
T Del Prete,
A. De Santo,
T Dignan,
L Di Lella,
E do Couto e Silva,
J Dumarchez,
M. Ellis,
T Fazio,
R Ferrari
[show abstract]
[hide abstract]
ABSTRACT: A study of strange particle production in charged current interactions has been performed using the data from the NOMAD experiment. Yields of neutral strange particles (K s , , ) have been measured. Mean multiplicities are reported as a function of the event kinematic variables E , W as well as of the variables describing particle behaviour within a hadronic jet: x F , z and p T . Decays of resonances and heavy hyperons with identified K s and in the final state have been analyzed. Clear signals corresponding to K have been observed.
01/2002;
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P. Astier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
M Banner, G Bassompierre,
N Besson,
I. Bird,
B Blumenfeld,
F. Bobisut, [......],
T Del Prete,
A. De Santo,
T Dignan,
L Di Lella,
E do Couto e Silva,
J Dumarchez,
M. Ellis,
T Fazio,
G J Feldman,
R Ferrari
[show abstract]
[hide abstract]
ABSTRACT: F.J.P. Soler h;t G. Sozzi D. Steele b;i U. Stiegler M. Stipcevi'c Th. Stolarczyk M. Tareb-Reyes G.N. Taylor V. Tereshchenko A. Toropin A.-M. Touchard S.N. Tovey h;k M.-T. Tran E. Tsesmelis J. Ulrichs L. Vacavant M. Valdata-Nappi d;1 V. Valuev f;j F. Vannucci K.E. Varvell M. Veltri V. Vercesi G. Vidal-Sitjes J.-M. Vieira T. Vinogradova F.V. Weber c;h T. Weisse F.F. Wilson L.J. Winton B.D. Yabsley H. Zaccone K. Zuber P. Zuccon LAPP, Annecy, France Johns Hopkins Univ., Baltimore, MD, USA Harvard Univ., Cambridge, MA, USA Univ. of Calabria and INFN, Cosenza, Italy Dortmund Univ., Dortmund, Germany JINR, Dubna, Russia Univ. of Florence and INFN, Florence, Italy CERN, Geneva, Switzerland University of Lausanne, Lausanne, Switzerland UCLA, Los Angeles, CA, USA University of Melbourne, Melbourne, Australia Inst. Nucl. Research, INR Moscow, Russia Univ. of Padova and INFN, Padova, Italy LPNHE, Univ. of P
05/2001;
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P. Astier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
M Banner, G Bassompierre,
K. Benslama,
N Besson,
I. Bird,
B Blumenfeld, [......],
J Dumarchez,
M. Ellis,
T Fazio,
G J Feldman,
R Ferrari,
D. Ferrere,
V. Flaminio,
M Fraternali,
J-M Gaillard,
E. Gangler
[show abstract]
[hide abstract]
ABSTRACT: We report on a search for heavy neutrinos (# 4 ) produced in the decay D s ## 4 at the SPS proton target followed by the decay # 4 e - in the NOMAD detector. Both decays are expected to occur if # 4 is a component of # # . From the analysis of the data collected during the 1996-1998 runs with 4.1 protons on target, a single candidate event consistent with background expectations was found. This allows to derive for the first time an upper limit on the mixing strength between the heavy neutrino and the tau neutrino in the # 4 mass range from 10 to 190 MeV. Windows between the SN1987a and Big Bang Nucleosynthesis lower limits and our result are still open for future experimental searches. The results obtained are used to constrain an interpretation of the time anomaly observed in the KARMEN1 detector.
04/2001;
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P. Astier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
M Banner, G Bassompierre,
K. Benslama,
N Besson,
I. Bird,
B Blumenfeld, [......],
L Di Lella,
E do Couto e Silva,
J Dumarchez,
M. Ellis,
T Fazio,
G J Feldman,
R Ferrari,
D. Ferr Ere,
V. Flaminio,
M Fraternali
[show abstract]
[hide abstract]
ABSTRACT: cevi c Th. Stolarczyk M. Tareb-Reyes G.N. Taylor V. Tereshchenko A. Toropin A.-M. Touchard S.N. Tovey M.-T. Tran E. Tsesmelis Preprint submitted to Elsevier Preprint 15 January 2001 J. Ulrichs L. Vacavant M. Valdata-Nappi d;1 V. Valuev f;j F. Vannucci K.E. Varvell M. Veltri V. Vercesi G. Vidal-Sitjes J.-M. Vieira T. Vinogradova F.V. Weber c;h T. Weisse F.F. Wilson L.J. Winton B.D. Yabsley H. Zaccone K. Zuber P. Zuccon LAPP, Annecy, France Johns Hopkins Univ., Baltimore, MD, USA Harvard Univ., Cambridge, MA, USA Univ. of Calabria and INFN, Cosenza, Italy Dortmund Univ., Dortmund, Germany JINR, Dubna, Russia Univ. of Florence and INFN, Florence, Italy CERN, Geneva, Switzerland University of Lausanne, Lausanne, Switzerland UCLA, Los Angeles, CA, USA University of Melbourne, Melbourne, Australia Inst. Nucl. Research, INR Moscow, Russia Univ. of Padova and INFN, Padova, Italy LPNHE, Univ. of Paris VI and VII
04/2001;
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P. Astier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
G. Ballocchi,
M Banner, G Bassompierre,
K. Benslama,
N Besson,
I. Bird, [......],
J Dumarchez,
M. Ellis,
T Fazio,
G J Feldman,
R Ferrari,
V. Flaminio,
M Fraternali,
J-M Gaillard,
E. Gangler,
A Geiser
[show abstract]
[hide abstract]
ABSTRACT: This paper presents the results of an analysis of opposite sign dimuon events carried out by the NOMAD collaboration. The distributions of various kinematic variables are compared with a theoretical model of dimuon production, constructed within the framework of leading order QCD, to yield a determination of the charm quark mass, m c , the strange quark fraction of the nucleon sea, , and the average semileptonic branching ratio, B c . The paper is organised as follows : Section 2 outlines the theoretical description of opposite sign dimuon production within the framework of leading order QCD and Section 3 gives a brief description of the neutrino beam. The detector is described in Section 4 along with a description of the simulation programs used in the analysis (Section 4.2), a description of the data selection process and a discussion of the background determination. Section 5 presents details of the analysis and Section 6 contains a discussion and a comparison with the results of other experiments. Finally, Section 7 summarizes the results. 4 2 Theory In the Standard Model, an opposite sign dimuon event is produced when a neutrino interacts, via a charged current, with a strange (s) or down (d) quark, producing a charm (c) quark. The charm quark fragments into a charmed hadron (most frequently a D meson) which can then decay semileptonically resulting in a final state containing two oppositely charged muons : the primary
07/2000;
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P Astier,
D Autiero,
A Baldisseri,
M Baldo-Ceolin,
G Ballocchi,
M Banner, G Bassompierre,
K Benslama,
N Besson,
I Bird,
B Blumenfeld,
F Bobisut
[show abstract]
[hide abstract]
ABSTRACT: In the context of a two-flavour approximation we reinterpret the published NOMAD limit on νμ→ντ oscillations in terms of νe→ντ oscillations. At 90% C.L. we obtain sin22θeτ
Physics Letters B - PHYS LETT B. 01/2000; 471(4):406-410.
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P. Astier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
G. Ballocchi,
M Banner, G Bassompierre,
K. Benslama,
N Besson,
I. Bird, [......],
G J Feldman,
R Ferrari,
D. Ferrere,
V. Flaminio,
M Fraternali,
J-M Gaillard,
E. Gangler,
A Geiser,
D. Gibin,
S. Gninenko
[show abstract]
[hide abstract]
ABSTRACT: In the context of a two-flavour approximation we reinterpret the published NOMAD limit on # # # # oscillations in terms of # e # # # oscillations. At 90% C.L. we obtain sin 2 2# e# < 5.2 10 -2 for large #m 2 , while for sin 2 2# e# = 1 the confidence region includes #m 2 < 11 eV 2 /c 4 . Key words: neutrino oscillations 1 Introduction In a recent article [1], we have reported results from a search for # # # # oscillations using the NOMAD detector to look for # # appearance in the CERN wide-band neutrino beam. The detection of the potential oscillation signal relies on the identification of # # charged-current (CC) interactions using kinematic criteria. The analysis described in Ref. [1] was based on data collected in the 1995, 1996 and 1997 runs, corresponding to approximately 950 000 # CC events in the detector fiducial volume. No oscillation signal was observed. Since the beam contains a small but significant # e component, # # 's can in principle also be pro...
12/1999;
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E. Auffray,
P Baillon,
D Barney, G Bassompierre,
Y. Benhammou,
A. Blick,
P Bloch,
P Bonamy,
J Bourotte,
L. Buiron, [......],
G Davies,
P. Depasse,
K Deiters,
M Diemoz,
L Dobrzynski,
S. Donskov,
H El-Mamouni,
C Ercoli,
J L Faure,
S. Gninenko
[show abstract]
[hide abstract]
ABSTRACT: Further tests of lead tungstate crystal matrices made in high energy electron beams in 1996, using new crystals, new APDs and an improved test setup confirm that an energy resolution of better than 0.6% at 100 GeV can be obtained when the longitudinal uniformity of the struck crystal is adequate. Light loss measurements under low dose irradiation are reported. It is shown that there is no loss of energy resolution after irradiation and it is demonstrated that the calibration change due to light loss can be tracked with a precision monitoring system. Successful tests with a preshower device, equipped with silicon strip detector readout, are also described. To be submitted to Nucl. Instr. and Meth. 2 1 RWTH 1, Aachen, Germany 2 LAPP, Annecy, France 3 University of Bristol, Bristol, U. K. 4 Rutherford Appleton Laboratory, Didcot, U.K. 5 CERN, Geneva, Switzerland 6 Saclay, Gif-sur-Yvette, France 7 Imperial College of Science Technology and Medicine, London, U.K. 8 ...
01/1998;
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J. Altegoer,
C. Angelini,
P. Astier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
G. Ballocchi,
M. Banner,
S. Basa, G. Bassompierre,
K. Benslama,
N. Besson
[show abstract]
[hide abstract]
ABSTRACT: NOMAD is a neutrino oscillation experiment designed to search for nutau appearance in the CERN-SPS wide band numu beam. Signal detection relies on the identification of nutau charged current interactions using kinematic criteria. The analysis of the 1995 data sample yields no oscillation signal. Combining all studied tau decay modes, a limit of sin22thetamutau < 4.2x10-3 is obtained for large Deltam2 at the 90% confidence level.
Physics Letters B - PHYS LETT B. 01/1998; 431:219-236.
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G Bassompierre,
M. Bermond,
M. Berthet,
T. Bertozzi,
C. Engster,
T Fazio,
G. Gaillard,
J-M Gaillard,
L. Mossuz,
E. Palazzini,
P. Petit,
P. Petitpas,
A Placci,
D. Sillou,
R. Sottile,
V. Valuev
[show abstract]
[hide abstract]
ABSTRACT: this paper, whereas charge integration leaves more flexibility in the off-line treatment. 2.3.2 Detector gas mixture The gas mixture chosen for the proportional detector of the TRD is made of 80% Xe, 20% CH 4 :
12/1997;
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[show abstract]
[hide abstract]
ABSTRACT: this paper we describe the algorithms developed for electron-pion discrimination by the NOMAD TRD and their performance. We review the design of the TRD and the principles of the electron identification in sections 2 and 3. The algorithms developed for the recognition of electrons are described in section 4 and discussed in section 5. The identification performance obtained on the data are described in section 6.
12/1997;
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J. Altegoer,
M. Anfreville,
C Angelini,
P. Astier,
M. Authier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
M Banner,
S. Basa, [......],
T Del Prete,
L Di Lella,
T Dignan,
E do Couto e Silva,
I. Donnelly,
J Dumarchez,
C. Engster,
T Fazio,
G J Feldman,
R Ferrari
[show abstract]
[hide abstract]
ABSTRACT: NOMAD is a neutrino oscillation experiment designed to search for ø appearance in the CERN-SPS wide band predominantly ¯ beam. Signal detection is based on the identification of ø charged current interactions with the help of kinematic criteria. After the completion of the detector in August, 1995 the experiment has been successfully taking data till the end of 1996. The detector performances are in good agreement with our expectations. Preliminary analysis based on the 1995 data sample allows NOMAD to achieve the limit of 4 Theta 10 Gamma3 on sin 2 2` ¯ø for large Deltam 2 . NOMAD will continue to run during 1997. If no evidence for oscillations is found in all the NOMAD data the sensitivity to the oscillation parameters is expected to be improved by an order of magnitude with respect to the current limit. a Univ. of Massachusetts, Amherst, USA b LAPP, Annecy, France c Univ. of Calabria INFN, Cosenza, Italy d CERN, Geneva, Switzerland e Dortmund Univ., Dortmund, G...
09/1997;
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J. Altegoer,
M. Anfreville,
C Angelini,
P. Astier,
M. Authier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
M Banner,
S. Basa, [......],
T Del Prete,
L Di Lella,
T Dignan,
E do Couto e Silva,
I. Donnelly,
J Dumarchez,
C. Engster,
T Fazio,
G J Feldman,
R Ferrari
[show abstract]
[hide abstract]
ABSTRACT: The NOMAD experiment has been optimized to detect primary electrons with good efficiency. e charged current interactions can be analysed to search for a ¯ ! e signal: no evidence for such a signal is observed in the NOMAD data collected during 1995 run. Comparing the ratio e = ¯ of observed e and ¯ charged current interactions to expectations shows no evidence for oscillations. A preliminary limit of sin 2 2` ! 1:8 Theta 10 Gamma3 can be set for high Deltam 2 . a Univ. of Massachusetts, Amherst, USA b LAPP, Annecy, France c Univ. of Calabria INFN, Cosenza, Italy d CERN, Geneva, Switzerland e Dortmund Univ., Dortmund, Germany f JINR, Dubna, Russia g Univ. of Florence INFN, Florence, Italy h Harvard Univ., Boston, USA i Johns Hopkins Univ., Baltimore, USA j University of Lausanne, Lausanne, Switzerland k UCLA, Los Angeles, USA l University of Melbourne, Melbourne, Australia m Inst. Nucl. Research, INR Moscow, Russia n Univ. of Padova INFN, Padov...
09/1997;
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J. Altegoer,
M. Anfreville,
C Angelini,
P. Astier,
M. Authier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
M Banner,
S. Basa, [......],
T Del Prete,
L Di Lella,
T Dignan,
E do Couto e Silva,
I. Donnelly,
J Dumarchez,
C. Engster,
T Fazio,
G J Feldman,
R Ferrari
[show abstract]
[hide abstract]
ABSTRACT: NOMAD is a short baseline neutrino oscillation experiment searching for ¯ ! ø and ¯ ! e oscillations in the CERN SPS wide band neutrino beam. The experiment has been collecting data since July 1995 and the data taking will continue until at least the end of 1997. A preliminary analysis based on the 1995 data sample allows NOMAD to set 90% confidence limits of sin 2 2` ¯ø ! 3:4 Theta 10 Gamma3 for ¯ ! ø and sin 2 2` ¯e ! 2 Theta 10 Gamma3 for ¯ ! e oscillations at large Deltam 2 . a Univ. of Massachusetts, Amherst, USA b LAPP, Annecy, France c Univ. of Calabria INFN, Cosenza, Italy d CERN, Geneva, Switzerland e Dortmund Univ., Dortmund, Germany f JINR, Dubna, Russia g Univ. of Florence INFN, Florence, Italy h Harvard Univ., Boston, USA i Johns Hopkins Univ., Baltimore, USA j University of Lausanne, Lausanne, Switzerland k UCLA, Los Angeles, USA l University of Melbourne, Melbourne, Australia m Inst. Nucl. Research, INR Moscow, Russia n ...
09/1997;
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J. Altegoer,
C Angelini,
P. Astier,
D. Autiero,
A. Baldisseri,
M. Baldo-Ceolin,
G. Ballocchi,
M Banner,
S. Basa, G Bassompierre, [......],
G Feldman,
R Ferrari,
D. Ferrere,
V. Flaminio,
M Fraternali,
J-M Gaillard,
P. Galumian,
E. Gangler,
A Geiser,
D. Gibin
[show abstract]
[hide abstract]
ABSTRACT: The NOMAD experiment is currently collecting data at the CERN SPS. The detector is now being completed, as specified in the original proposal, and has been further improved. All subdetectors are functioning well. The experiment is searching for ¯ ! ø neutrino oscillations and is sensitive to the mass difference squared Deltam 2 ? 0:7 eV 2 . Maximal sensitivity with respect to existing experimental limits is obtained for Deltam 2 ? 20 eV 2 where, if no oscillations events are seen, the excluded domain would improve by an order of magnitude. Preliminary measurements are presented from the 1994 and 1995 data samples. 1 Univ. of Massachusetts, Amherst, USA 2 LAPP, Annecy, France 3 Univ. of Calabria INFN, Cosenza, Italy 4 CERN, Geneva, Switzerland 5 Dortmund Univ., Dortmund, Germany 6 Dubna Univ., JINR, Russia 7 Univ. of Florence INFN, Florence, Italy 8 Harvard Univ., Boston, USA 9 Johns Hopkins Univ., Baltimore, USA 10 University of Lausanne, Lausanne, Switze...
09/1995;
