Performance Study of the CMS Ecal Electronics using electrons from 15 GeV to 250 GeV

The experimental conditions and physics goals of LHC experiments set challenging specifications for detectors and their readout electronics. The CMS Electromagnetic Calorimeter (Ecal) is an example of a complex system in which every component needs to be understood in detail in order to ensure the quality of the physics results. In 2006, 9 ECAL supermodules were exposed to an electron test beam in the energy range from 15 GeV and 250 GeV. Many aspects of the calorimeter response have been studied in detail. We will describe the results of these studies, with emphasis on the contribution of the electronics to linearity, resolution and noise of the system

b hadron production, spectroscopy and properties at CMS

Precise measurements of production and properties of hadrons containing a b quark, performed using data collected by the CMS experiment at the LHC, are reported. These are important to investigate underlying mechanisms in QCD describing heavy quarks. The dependencies on transverse momentum and rapidity are investigated. Comparisons with theory expectations and among different collision energies are provided

Status and perspectives of the Pierre Auger cosmic ray observatory

The problem of the origin of Ultra High Energy Cosmic Rays, that is those with an energy of the Primary above 1019 eV, is a challenging one. The expected flux at those energies is around 1/yr/km2, thus requiring an unprecedented size of the detector in order to achieve consistent statistics. The Pierre Auger Observatory will be the largest cosmic ray detector ever built, consisting of two sites, one for each hemisphere, equipped with 1600 water Cherenkov detectors and four fluorescence detectors, covering each 3000 km 2. The combination of the two techniques, referred to as the hybrid technique, results in unprecedented accuracy in the reconstruction of the air showers. The concept has been validated with an Engineering Array of 32 water tanks and two fluorescence telescopes, during which the apparatus demonstrated very good performances. This paper will summarize the features of the data, the reconstruction methods and the strategy toward completion of the full Observatory

The LiTE-DTU: A Data Conversion and Compression ASIC for the Readout of the CMS Electromagnetic Calorimeter

International audienceThe high-luminosity phase of operation of the CERN Large Hadron Collider (HL-LHC) will pose new challenges to the detectors and their readout electronics. In particular, the Compact Muon Solenoid (CMS) barrel electromagnetic calorimeter will require a full redesign of the electronic readout chain in order to cope with the increase in luminosity and trigger rate. In this framework, a new application-specific integrated circuit (ASIC) integrating A/D conversion, lossless data compression, and high-speed transmission has been developed and tested. The ASIC, named Lisboa-Torino Ecal Data Transmission Unit (LiTE-DTU), is designed in a commercial CMOS 65-nm process and embeds two 12-bit, 160-MS/s analog-to-digital converters (ADCs), a data selection and compression logic, and a 1.28-Gb/s output serial link. The high-speed 1.28-GHz clock is generated internally from the 160-MHz input by a clock multiplication phase-locked loop (PLL). The circuit has been designed implementing radiation-tolerant techniques in order to work in the harsh environment of the HL-LHC upgrade. The LiTE-DTU is currently in the preproduction phase. A sample of 600 chips has been tested and incorporated into front-end (FE) boards for systems performance testing