Measurement of the Underlying Event at LHC with the CMS detector

A study of \textit{Underlying Events} (UE) at \textit{Large Hadron Collider} (LHC) with CMS detector under nominal conditions is discussed. Using charged particle and charged particle jets, it will be possible to discriminate between various QCD models with different multiple parton interaction schemes, which correctly reproduce Tevatron data but give different predictions when extrapolated to the LHC energy. This will permit improving and tuning Monte Carlo models at LHC start-up, and opens prospects for exploring QCD dynamics in proton-proton collisions at 14TeV

The Underlying Event at the LHC

We discuss a study of "minimum-bias'' collisions and the "Underlying Event" at CMS (under nominal conditions) by measuring charged particles and muons. The Underlying Event is studied by examining charged particles in the "transverse" region in charged particle jet production and in the central region of Drell-Yan muon-pair production (after removing the muon-pair)

Calorimetry Task Force Report

In this note we summarize the studies and recommendations of the calorimeter simulation task force (CaloTF). The CaloTF was established in February 2008 in order to understand and reconcile the discrepancies observed between the CMS calorimetry simulation and the test beam data recorded during 2004 and 2006. As the result of studies by the CaloTF a new version of Geant4 was developed and introduced in the CMS detector simulation leading to significanly better agreement with test beam data. Fast and flexible parameterizations describing showering in the calorimeter are introduced both in the Full Simulation (with a Gflash-like approach) and in the Fast Simulation. The CaloTF has developed a strategy to rapidly tune the CMS calorimeter simulation using the first LHC collision data when it becomes available. The improvements delivered by the CaloTF have been implemented in the software release CMSSW 2.1.0

PPPC 4 DM ID: A Poor Particle Physicist Cookbook for Dark Matter Indirect Detection

We provide ingredients and recipes for computing signals of TeV-scale Dark Matter annihilations and decays in the Galaxy and beyond. For each DM channel, we present the energy spectra of electrons and positrons, antiprotons, antideuterons, gamma rays, neutrinos and antineutrinos e, mu, tau at production, computed by high-statistics simulations. We estimate the Monte Carlo uncertainty by comparing the results yielded by the Pythia and Herwig event generators. We then provide the propagation functions for charged particles in the Galaxy, for several DM distribution profiles and sets of propagation parameters. Propagation of electrons and positrons is performed with an improved semi-analytic method that takes into account position-dependent energy losses in the Milky Way. Using such propagation functions, we compute the energy spectra of electrons and positrons, antiprotons and antideuterons at the location of the Earth. We then present the gamma ray fluxes, both from prompt emission and from Inverse Compton scattering in the galactic halo. Finally, we provide the spectra of extragalactic gamma rays. All results are available in numerical form and ready to be consumed.Comment: 57 pages with many figures and tables. v4: updated to include a 125 higgs boson, computation and discussion of extragalactic spectra corrected, some other typos fixed; all these corrections and updates are reflected on the numerical ingredients available at http://www.marcocirelli.net/PPPC4DMID.html they correspond to Release 2.

Tracker Operation and Performance at the Magnet Test and Cosmic Challenge

During summer 2006 a fraction of the CMS silicon strip tracker was operated in a comprehensive slice test called the Magnet Test and Cosmic Challenge (MTCC). At the MTCC, cosmic rays detected in the muon chambers were used to trigger the readout of all CMS sub-detectors in the general data acquisition system and in the presence of the 4 T magnetic field produced by the CMS superconducting solenoid. This document describes the operation of the Tracker hardware and software prior, during and after data taking. The performance of the detector as resulting from the MTCC data analysis is also presented

The Limits of Space Radiation Magnetic Shielding: An Updated Analysis

A major problem of long-duration manned missions in the deep space is the flow of high energy charged particles of solar (SPE) and galactic (GCR) origin. SPE has short duration but can be extremely intense and can lead to acute, even lethal, effects. GCR flow is much less intense but is continuous, isotropic, and more energetic; it increases the risk of carcinogenesis and can affect the nervous and cardiovascular systems, restricting the endurance of missions to few months. It is commonly believed that the problem of space radiation can be solved by surrounding the spacecraft habitats with large superconducting magnets, even though a considerable technological effort would be required. However, magnetic shielding has several basic limitations, which restrict the reduction of the radiation dose: they range from the biological effect of the particles in the high region of the GCR spectrum, higher than the shield cutoff energy, to the generation of secondary particles due to the interaction of cosmic rays with magnet and spacecraft materials. The physical and technological constraints of space radiation magnetic shields are discussed in this paper. Despite such limitations, a superconducting magnet could completely eliminate the risk due to SPE. Moreover, it could reduce the GCR adsorbed dose enough to make acceptable the risk of developing long term diseases after a return trip to Mars

Calorimetry Task Force Report

In this note we summarize the progress made by the calorimeter simulation task force (CaloTF) over the past year. The CaloTF was established in February 2008 in order to understand and reconcile the discrepancies observed between the CMS calorimetry simulation and test beam data recorded during 2004 and 2006. The simulation has been significantly improved by using a newer version of Geant4 and an improved physics list for the full CMS detector simulation. Simulation times have been reduced by introducing flexible parameterizations to describe showering in the calorimeter (using a Gflash-like approach) which have been tuned to the test beam data

Test of the Inner Tracker: Silicon Microstrip Modules

The inner portion of the CMS microstrip Tracker consists of 3540 silicon detector modules; its construction has been under full responsibility of seven INFN (Istituto Nazionale di Fisica Nucleare) and University laboratories in Italy. In this note procedures and strategies, which were developed and perfected to qualify the Tracker Inner Barrel and Inner Disks modules for installation, are described. In particular the tests required to select highly reliable detector modules are illustrated and a summary of the results from the full Inner Tracker module test is presented

Experimental verification of the HERD prototype at CERN SPS

<p> The High Energy cosmic-Radiation Detection (HERD) facility is one of several space astronomy payloads of the cosmic light house program onboard China&#39;s Space Station, which is planned for operation starting around 2020 for about 10 years. Beam test with a HERD prototype, to verify the HERD specifications and the reading out method of wavelength shifting fiber and image intensified CCD, was taken at CERN SPS in November, 2015. The prototype is composed of an array of 5&lowast;5&lowast;10 LYSO crystals, which is 1/40th of the scale of HERD calorimeter. Experimental results on the performances of the calorimeter are discussed. &copy; 2016 SPIE.</p