Alignement strategy for the Inner Detector of ATLAS

002704675 ATLAS is a general-purpose spectrometer in preparation for taking data at the Large Hadron Collider at CERN. It will start operation in autumn 2007. Charged particle tracking is realized by the Inner Detector. The Inner Detector consists of two silicon subsystems: a Pixel Detector and a Semiconductor Tracker complemented by straw proportional gas chambers. In order to exploit the excellent intrinsic resolution of the precision tracking devices high accuracy alignment is required. In this report the strategy to align the sub-detectors of the ATLAS Inner Detector is reviewed, together with the current status of preparation. Both track-based and hardware alignment methods are presented

Least Squares Approach to the Alignment of the Generic High Precision Tracking System

A least squares method to solve a generic alignment problem of high granularity tracking system is presented. The formalism takes advantage of the assumption that the derived corrections are small and consequently uses the first order linear expansion throughout. The algorithm consists of analytical linear expansion allowing for multiple nested fits. E.g. imposing a common vertex for groups of particle tracks is of particular interest. We present a consistent and complete recipe to impose constraints on any set of either implicit or explicit parameters. The baseline solution to the alignment problem is equivalent to the one described in [1]. The latter was derived using purely algebraic methods to reduce the initial large system of linear equations arising from separate fits of tracks and alignment parameters. The method presented here benefits from wider range of applications including problems with implicit vertex fit, physics constraints on track parameters, use of external information to constrain the geometry, etc. The complete formalism is given in [2]. The method has been applied to the full simulation of the ATLAS silicon tracking system. The ultimate goal is to determine ~35,000 degrees of freedom. We present a limited scale exercise exploring various aspects of the solution

Detector Technologies for CLIC

The Compact Linear Collider (CLIC) is a high-energy high-luminosity linear electron-positron collider under development. It is foreseen to be built and operated in three stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively. It offers a rich physics program including direct searches as well as the probing of new physics through a broad set of precision measurements of Standard Model processes, particularly in the Higgs-boson and top-quark sectors. The precision required for such measurements and the specific conditions imposed by the beam dimensions and time structure put strict requirements on the detector design and technology. This includes low-mass vertexing and tracking systems with small cells, highly granular imaging calorimeters, as well as a precise hit-time resolution and power-pulsed operation for all subsystems. A conceptual design for the CLIC detector system was published in 2012. Since then, ambitious R&D programmes for silicon vertex and tracking detectors, as well as for calorimeters have been pursued within the CLICdp, CALICE and FCAL collaborations, addressing the challenging detector requirements with innovative technologies. This report introduces the experimental environment and detector requirements at CLIC and reviews the current status and future plans for detector technology R&D.Comment: 152 pages, 116 figures; published as CERN Yellow Report Monograph Vol. 1/2019; corresponding editors: Dominik Dannheim, Katja Kr\"uger, Aharon Levy, Andreas N\"urnberg, Eva Sickin

HE-LHC: The High-Energy Large Hadron Collider – Future Circular Collider Conceptual Design Report Volume 4

In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100 km tunnel infrastructure, as well as the physics opportunities of these two colliders, and a high-energy LHC, based on FCC-hh technology. This document constitutes the third volume of the FCC Conceptual Design Report, devoted to the hadron collider FCC-hh. It summarizes the FCC-hh physics discovery opportunities, presents the FCC-hh accelerator design, performance reach, and staged operation plan, discusses the underlying technologies, the civil engineering and technical infrastructure, and also sketches a possible implementation. Combining ingredients from the Large Hadron Collider (LHC), the high-luminosity LHC upgrade and adding novel technologies and approaches, the FCC-hh design aims at significantly extending the energy frontier to 100 TeV. Its unprecedented centre-of-mass collision energy will make the FCC-hh a unique instrument to explore physics beyond the Standard Model, offering great direct sensitivity to new physics and discoveries

The Compact Linear Collider (CLIC) - 2018 Summary Report

The Compact Linear Collider (CLIC) is a TeV-scale high-luminosity linear $e^+e^-$ collider under development at CERN. Following the CLIC conceptual design published in 2012, this report provides an overview of the CLIC project, its current status, and future developments. It presents the CLIC physics potential and reports on design, technology, and implementation aspects of the accelerator and the detector. CLIC is foreseen to be built and operated in stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively. CLIC uses a two-beam acceleration scheme, in which 12 GHz accelerating structures are powered via a high-current drive beam. For the first stage, an alternative with X-band klystron powering is also considered. CLIC accelerator optimisation, technical developments and system tests have resulted in an increased energy efficiency (power around 170 MW) for the 380 GeV stage, together with a reduced cost estimate at the level of 6 billion CHF. The detector concept has been refined using improved software tools. Significant progress has been made on detector technology developments for the tracking and calorimetry systems. A wide range of CLIC physics studies has been conducted, both through full detector simulations and parametric studies, together providing a broad overview of the CLIC physics potential. Each of the three energy stages adds cornerstones of the full CLIC physics programme, such as Higgs width and couplings, top-quark properties, Higgs self-coupling, direct searches, and many precision electroweak measurements. The interpretation of the combined results gives crucial and accurate insight into new physics, largely complementary to LHC and HL-LHC. The construction of the first CLIC energy stage could start by 2026. First beams would be available by 2035, marking the beginning of a broad CLIC physics programme spanning 25-30 years

Status of Beyond Standard Model Higgs searches at the LHC On behalf of the ATLAS and CMS Collaborations

An overview of searches for Beyond Standard Model physics phenomena in the Higgs sector from the ATLAS and the CMS experiments in LHC Run 1 is given. Both indirect limits as well as direct searches for various extensions of the scalar sector are covered. The review presents a wide scope of results and concentrates on the most recent analyses