Susygen3, an Event Generator for Linear Colliders

The Monte Carlo program \texttt{SUSYGEN}, initially designed for computing distributions and generating events for supersymmetric particle production in $e^+e^-$ collisions, has now been upgraded to study supersymmetric processes at linear colliders by the inclusion of beamstrahlung, beam polarization, spin correlations and complex couplings including CP violating phases. It continues to offer, in the new context, the possibility to study the production and decay of supersymmetric particles within the most general minimal standard supersymmetric model (MSSM), the minimal supergravity model (MSUGRA) or the gauge mediated supersymmetry breaking model (GMSB), with or without assuming R-parity conservation.Comment: 5 pages, 3figures. Contribution to the Proceedings of the International Workshop on Linear Colliders, Sitges (Spain

Compilation of SUSY particle spectra from Snowmass 2001 benchmark models

A comparative study of supersymmetric particle spectra calculated by the programs ISAJET, SUSYGEN and PYTHIA is presented for various SUSY scenarios defined at the Snowmass 2001 workshop.Comment: 91 pages, 26 figure

Chargino searches at LEP for complex MSSM parameters

We reanalyze the results of the chargino searches at LEP (on the basis of the DELPHI 189 GeV data sample), including the possibility of complex MSSM parameters. We point out the possible differences between the complex- and real-parameter analysis. We check that the regions excluded by ``standard'' analyses remain generally robust against the introduction of complex parameters, with the exception of light sneutrino and low $\tan\beta$ scenario, where additional constraints like those given by the $Z^0$ width or electric dipole moment measurements are necessary.Comment: 27 pages, 16 figures, uses axodraw.st

Recherche de sélectrons et de smuons dans l'expérience DELPHI au LEP

The main topic of this Thesis is the minimal supersymmetric extension of the Standard Model (MSSM). In the first part, we reanalyze the results of the chargino searches at LEP (on the basis of the DELPHI 189 GeV data sample) including the possibility of complex MSSM parameters. We study how they affect the present limits and how these limits are restored by the use of the experimental upper limit on the electric dipole moment of electron. In the second part, we use the Helicity Amplitude Method for cross section calculation. With this technique, we evaluate the main supersymmetric particle production cross sections at leptonic colliders. We also show how the spin correlations are important when one attempts to evaluate the MSSM parameters, using the angular distribution of final particles. In the last section, an analysis for selectron and smuon searches with the DELPHI detector at LEP is presented. To extract the selectron and smuon signal (two acoplanar electrons or muons of opposite charge) from the Standard Model background (W+W- and gamma gamma processes), we develop an analysis based on a Neural Network for each selectron and smuon mass hypothesis. The analysis of data for a center of mass energy from 184 to 202 GeV, for an equivalent integrated luminosity of 440 pb-1 , did not show any significant deviation of the number of events from the Standard Model predictions. This enables us to put a lower bound on the selectron and the smuon masses.Dans cette thèse, nous traitons de l'extension supersymétrique minimale du Modèle Standard (MSSM). Dans un premier temps, Nous analysons les conséquences de l'introduction des phases supersymétriques dans le MSSM. Nous examinons la stabilité des limites obtenues sans phases pour la recherche de charginos pour une énergie de 189 GeV par l'expérience DELPHI du LEP. Ensuite, nous montrons l'importance des corrélations de spin pour l'extraction des paramètres du MSSM à partir des distributions angulaires des particules finales. Pour celà nous utilisons la méthode des amplitudes d'hélicité pour le calcul des sections efficaces associées à la production des particules supersymétriques. Enfin, nous développons une analyse pour la recherche des partenaires supersymétriques des électrons et des muons (sélectrons et smuons) lors des collisions électron positron avec le détecteur DELPHI du LEP. Nous utilisons une méthode fondée sur un réseau de neurones pour extraire le signal (deux leptons acoplanaires de même saveur et de charges opposées) des processus issus du Modèle Standard (les processus W+W- et les processus à deux photons). L'analyse des données recueillies pour les énergies de collision de 184 à 202 GeV, soit une luminosité équivalente de 440pb-1 n'a montré aucune déviation significative par rapport aux prédictions du Modèle Standard. Nous avons donc établi une limite inférieure sur la masse du sélectron et du smuon

Development of thin pixel sensors and a novel interconnection technology for the SLHC

We present an R&D activity aiming to develop a new detector concept in the framework of the ATLAS pixel detector upgrade in view of the Super-LHC. The new devices combine 75–150 μm thick pixels sensors with a vertical integration technology. A new production of thin pixel sensors on n- and p-type material is under way at the MPI Semiconductor Laboratory. These devices will be connected to the ATLAS read-out electronics with the new Solid–Liquid InterDiffusion technique as an alternative to the bump-bonding process. We also plan for the signals to be extracted from the back of the electronics wafer through Inter-Chip-Vias. The compatibility of the Solid–Liquid InterDiffusion process with the silicon sensor functionality has already been demonstrated by measurements on two wafers hosting diodes with an active thickness of 50 μm

A repository for beyond-the-standard-model tools

To aid phenomenologicalstudies of Beyond-the-Standard-Model (BSM)physics scenarios, a web repository for BSM calculational tools hasbeen created. We here present brief overviews of the relevant codes,ordered by topic as well as by alphabet. The online version of the repository may be found at http://www.ippp.dur.ac.uk/montecarlo/BSM

Les Houches physics at TeV colliders 2005 beyond the standard model working group: Summary report

The work contained herein constitutes a report of the Beyond the Standard Model'' working group for the Workshop Physics at TeV Colliders, Les Houches, France, 2-20 May, 2005. We present reviews of current topics as well as original research carried out for the workshop. Supersymmetric and non-supersymmetric models are studied, as well as computational tools designed in order to facilitate their phenomenology