This thesis presents the design qualification and construction of the Beam Scintillator Counter (BSC) for the CMS Collaboration at CERN in 2007 - 2008. The BSC detector is designed to aid in the commissioning of the Compact Muon Solenoid (CMS) during the first 2 years of operation and provide technical triggering for beam halo and minimum-bias events. Using plastic scintillator tiles mounted at both ends of CMS, it will detect minimum ionizing particles through the low-to-mid luminosity phases of the Large Hadron Collider (LHC) commissioning. During these early phases, the BSC will provide probably the most interesting and widely used data of any of the CMS sub-detectors and will be employed in the track based alignment procedure of the central tracker and commissioning of the Forward Hadron Calorimeter.

Heidelberg, Univ., Diss., 2007. / Online publiziert: 2008.

Techn. Univ., Diss., 2002--Darmstadt

The position reconstruction performance of the Electromagnetic Endcap Calorimeter (EMEC) is assessed in terms of its response to electrons. The electromagnetic and hadronic endcap calorimeter modules of the ATLAS detector are exposed to beams of electrons, pions, and muons in the energy range 6 GeV ≤ E ≤ 200 GeV at several impact positions in the pseudo-rapidity 1.6 ≤ |η| ≤ 1.8 in a beam test at CERN. The EMEC is a lead-liquid argon sampling calorimeter with a unique accordion structure designed to provide complete hermiticity and excellent energy and position resolution, the attribute on which several physics measurements envisioned at the LHC will depend. Unlike the real ATLAS situation, the beam test setup used a non-pointing geometry in η due to the experimental constraints. Hence, the position resolution of the EMEC is evaluated in the φ direction only and found to be at least as good as σφ = (4.36 ± 0.10)/ √E (12.64 ± 0.82) / E (0.00 ± 0.10) in milliradians.

The High Radiation to Materials facility employs a high intensity pulsed beam imposing several challenges on the beam position monitors. Diamond has been shown to be a resilient material with its radiation hardness and mechanical strength, while it is also simple due to its wide bandgap removing the need for doping. A new type of diamond based beam position monitor has been constructed, which includes a hole in the center of the diamond where the majority of the beam is intended to pass through. This increases the longevity of the detectors as well as allowing them to be used for high intensity beams. The purpose of this thesis is to evaluate the performance of the detectors in the High Radiation to Materials facility for various beam parameters, involving differences in position, size, bunch intensity and bunch number. A prestudy consisting of calibration of the detectors using single incident particles is also presented. The detectors are shown to work as intended after a recalibration of the algorithm, albeit with a slightly lower precision than requested, giving a promising new beam position monitoring system. They work for the full intensity range and a single bunch resolution is achieved. Functionality is also shown with backscattering from dense targets.

Dissertação (mestrado)—Universidade de Brasília, Centro de Desenvolvimento Sustentável, 2008. / Submitted by Diogo Trindade Fóis (diogo_fois@hotmail.com) on 2009-09-22T12:31:49Z No. of bitstreams: 1 2008_RafaelPintoDuarte.pdf: 1983234 bytes, checksum: 83fa3233679c7ddf1b16f5c6ddb04f19 (MD5) / Approved for entry into archive by Gomes Neide(nagomes2005@gmail.com) on 2010-02-08T17:37:13Z (GMT) No. of bitstreams: 1 2008_RafaelPintoDuarte.pdf: 1983234 bytes, checksum: 83fa3233679c7ddf1b16f5c6ddb04f19 (MD5) / Made available in DSpace on 2010-02-08T17:37:13Z (GMT). No. of bitstreams: 1 2008_RafaelPintoDuarte.pdf: 1983234 bytes, checksum: 83fa3233679c7ddf1b16f5c6ddb04f19 (MD5) Previous issue date: 2008-03-11 / Este trabalho analisa o papel da cooperação internacional no processo de desenvolvimento científico e tecnológico brasileiro, tendo como base a cooperação entre o Brasil e a Organização Européia para Pesquisa Nuclear (CERN). Analisa a agenda internacional nas estratégias nacionais de desenvolvimento em C&T desde os anos 1970. Propõe uma visão estratégica de um ciclo que envolve intercâmbio e colaborações científicas internacionais como etapas iniciais que levam à Cooperação Internacional (CI), esta última verdadeiramente capaz de gerar desenvolvimento científico. O estudo de caso sobre a participação de cientistas brasileiros no CERN mostra que a CI só gera desenvolvimento científico se contar com a participação do Estado para garantir investimentos e apoio institucional aos cientistas brasileiros no longo prazo. Assim a CI torna-se elemento indispensável para a elaboração e execução de políticas públicas que vislumbrem o desenvolvimento científico e tecnológico nacional. _______________________________________________________________________________ ABSTRACT / The present work studies the role of international cooperation on the Brazilian scientific and technological (S&T) development process, based on the case of the cooperation among Brazil and the European Organization for Nuclear Research (CERN). It starts at an analysis of the national strategies for S&T development since the 1970’s. The studies lead to a suggestion of a new strategic approach of a system beginning starting at activities of international S&T interchange and collaborations as initial stage that lead to International Cooperation, seen as the only one capable of create S&T development. The case of the Brazilian activities at CERN shows that International Cooperation generates S&T development only with long term assured financial and institutional support of the Government. The results point to the assumption that International Cooperation is an essential element for elaboration and execution of public policies that aim national development on science and technology.

No description available.

Title: Measurement of the B0 d meson lifetime at ATLAS detector Author: Pavel Řezníček Department: Institute of Particle and Nuclear Physics Supervisor of the doctoral thesis: Dr. Zdeněk Doležal Supervisor's e-mail address: Zdenek.Dolezal@mff.cuni.cz Abstract: The lifetime of B0 d mesons is determined from their decays B0 d → J/ψK∗0 reconstructed in ATLAS experiment at the LHC using pp collision data at a center-of-mass energy of 7 TeV and corresponding to integrated luminosity of 40 pb−1 . The lifetime, extracted from the simultaneous unbinned maximum likelihood mass-lifetime fit, is 1.51±0.04 (stat.)±0.04 (syst.) ps. A total number of 2750±90 (stat.) signal B0 d decays are observed in the measurement, with a fit- ted B0 d mass of 5363.7 ± 1.2 (stat.) MeV. Both the extracted B0 d meson mass and lifetime are within the determined errors consistent with the world average values. Although the achieved precision is still significantly lower than the one of the world average value, the measurement successfully tested the feasibility of the fit-method and allowed to cross-check ATLAS detector performance. Keywords: CERN, LHC, ATLAS, B-physics, B-hadron, Lifetime

This thesis presents the ADT transverse instability detection system, the next generation of instability detection in the LHC at CERN, Geneva. The system is presented after a thorough study of underlying causes for instabilities in high energy particle accelerators, current parallel programming paradigms, the available hardware and software at CERN and possible instability detection techniques. The requirements for the system involve handling vast amounts of data which need to be analyzed in real-time and in this data detect rapid amplitude growth while limiting the computational resources required to a minimum. The result of this thesis was a system that could generate a trigger when an instability was detected, which was used to save data from observation instruments around the LHC. A fixed display in the CERN control centre was also created which allows scientists and operators at CERN to monitor the oscillation amplitude of all particle bunches. The conclusion is that the complete system will be a valuable asset at CERN to help further develop the LHC.

Neutral current Drell-Yan production in proton-proton collisions at the LHC was studied with the ATLAS detector. The 20.1 inverse femtobarn data set used in this precision measurement was collected in 2012 during which the LHC collided protons at a centre-of-mass energy of 8 TeV. The production rate or differential cross-section was measured in three-dimensions: invariant mass, absolute rapidity, and cosine of the polar angle in the Collins-Soper frame. A measurement of the forward-backward asymmetry was obtained from the differential cross-section by summing over the forward and the backward events and taking their difference. The three-dimensional differential cross-section measurement presented in this dissertation can be used to constrain the invariant mass- and rapidity-dependent parton distribution functions of the proton and the forward-backward asymmetry results can be used to extract a measurement of the weak mixing angle. / Graduate