G. Coignet

The AMS-02 electromagnetic calorimeter

Abstract The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a lead-scintillanting fibers sampling calorimeter characterized by high granularity that allows to image the longitudinal and lateral showers development, a key issue to provide high electron/hadron discrimination. The light collection system and the FE electronics are designed to let the calorimeter operate over a wide energy range from few GeV up to 1 TeV. A full-scale prototype of the e.m. calorimeter was tested at Cern in October 2001 using electrons and pions beams with energy ranging from 3 to 100 GeV. Effective sampling thickness, linearity and energy resolution were measured.

Conceptual Design of a Multipurpose Beauty Factory Based on Superconducting Cavities

Abstract The conceptual design of a high luminosity (1033–1034 cm−2 s−1) beauty factory (W = 10–20 GeV) based on a superconducting linear collider with recirculators and damping rings is discussed in detail. Such an accelerator complex opens not only the possibility of performing interesting experiments in the energy range where c c and b b quark pairs are abundantly produced, but can continuous linear accelerator for nuclear physics and can support competitive programs in the field of synchrotron light and power FELs. Around it the new techniques needed for future high luminosity TeV linear colliders could be developed and, at a later stage, be used to build a Z factory or a toponium factory.

The Electromagnetic Calorimeter Trigger System for the AMS-02 Experiment

AMS-02 is an astroparticle experiment designed for a very precise measurement of the primary cosmic rays spectrum. The experiment will operate on board the ISS at a 400 km altitude for a period of about 3 years. The main scientific goals of the experiment are the search for antimatter, for dark matter and the study of gamma rays. In AMS-02 the electromagnetic calorimeter plays a key role for its high capability to measure e+, e- and gamma spectra and to suppress the background generated by p and He nuclei. To directly detect photons the calorimeter must provide a stand alone trigger. The proposed trigger, presented in this article, will have the capability to detect photons with energy above 4 GeV with an efficiency of about 100%. The hardware implementation comprises an analog section, comparing the photomultiplier signal with a given threshold, and a digital section applying the trigger selection algorithm.

A reduced scale e.m. calorimeter prototype for the AMS-02 experiment

A reduced scale prototype of the Pb-SciFi sampling e.m. calorimeter for the AMS-02 experiment was tested at CERN SPS beam line X5 at energies from 5 to 250 GeV. The detector was equalized with minimum ionizing particles and calibrated with electron beams. Effective sampling thickness, linearity and energy resolution were measured (C) 2002 Elsevier Science B.V. All rights reserved.

Searches for new physics

Most of the recent researches for new physics performed with high energy accelerators are reviewed: Results are reported for Minimal and Non Minimal Standard Model Higgs bosons, SUSY particles, Rare Decays of Z and tau, Leptoquarks and Leptogluons, and Compositeness. No evidence for a positive signal is reported, but significant and constraining limits are placed.

ELECTROMAGNETIC CALORIMETER FOR THE AMS-02 EXPERIMENT

The electromagnetic calorimeter (ECAL) of the AMS-02 experiment is a 3-dimensional sampling calorimeter, made of lead and scintillating fibers. The detector allows for a high granularity, with 18 samplings in the longitudinal direction, and 72 sampling in the lateral direction. The ECAL primary goal is to measure the energy of cosmic rays up to few TeV, however, thanks to the fine grained structure, it can also provide the separation of positrons from protons, in the GeV to TeV region. A direct measurement of high energy photons with accurate energy and direction determination can also be provided.

A superconducting radiofrequency e+e− linear collider for bottom quark and nuclear physics studies

Abstract The design of an accelerator complex based on recirculated linacs is presented. It could be used as a b- b hadron factory and simultaneously it could provide nearly continuous beams for nuclear physics studies. The expected performances of this accelerator are given. The main components and the associated developments are mentioned. The characteristics of the associated detector requested to perform an original b- b physics program are also listed. Finally, possible extensions offered by the accelerator complex are presented.