Search results for "Collider"
showing 10 items of 1690 documents
Search for an Invisibly Decaying Z′ Boson at Belle II in e+e−→μ+μ−(e±μ∓) Plus Missing Energy Final States
2020
Theories beyond the standard model often predict the existence of an additional neutral boson, the Z′. Using data collected by the Belle II experiment during 2018 at the SuperKEKB collider, we perform the first searches for the invisible decay of a Z′ in the process e+e-→μ+μ-Z′ and of a lepton-flavor-violating Z′ in e+e-→e±μZ′. We do not find any excess of events and set 90% credibility level upper limits on the cross sections of these processes. We translate the former, in the framework of an Lμ-Lτ theory, into upper limits on the Z′ coupling constant at the level of 5×10-2-1 for MZ′≤6 GeV/c2.
Higgs boson self-coupling measurements using ratios of cross sections
2013
We consider the ratio of cross sections of double-to-single Higgs boson production at the Large Hadron Collider at 14 TeV. Since both processes possess similar higher-order corrections, leading to a cancellation of uncertainties in the ratio, this observable is well-suited to constrain the trilinear Higgs boson self-coupling. We consider the scale variation, parton density function uncertainties and conservative estimates of experimental uncertainties, applied to the viable decay channels, to construct expected exclusion regions. We show that the trilinear self-coupling can be constrained to be positive with a 600/fb LHC dataset at 95% confidence level. Moreover, we demonstrate that we expe…
Measuring anomalous couplings inH→WW*decays at the International Linear Collider
2013
The measurement of the Higgs coupling to $W$ bosons is an important test of our understanding of the electroweak symmetry-breaking mechanism. We study the sensitivity of the International Linear Collider (ILC) to the presence of anomalous $H{W}^{+}{W}^{\ensuremath{-}}$ couplings using $ZH\ensuremath{\rightarrow}\ensuremath{\nu}\overline{\ensuremath{\nu}}W{W}^{*}\ensuremath{\rightarrow}\ensuremath{\nu}\overline{\ensuremath{\nu}}4j$ events. Using an effective Lagrangian approach, we calculate the differential decay rates of the Higgs boson including the effects of new dimension-five operators. We present a Monte Carlo simulation of events at the ILC, using a full detector simulation based on …
Limits on anomalous trilinear gauge couplings fromWW→e+e−,WW→e±μ∓, andWW→μ+μ−events frompp¯collisions ats=1.96 TeV
2006
Limits are set on anomalous WW gamma and WWZ trilinear gauge couplings using W+W--> e(+)nu(e)e(-)(nu) over bar (e), W+W--> e(+/-)nu(e)mu(-/+)nu(mu), and W+W-->mu(+)nu(mu)mu(-)(nu) over bar (mu) events. The data set was collected by the Run II D0 detector at the Fermilab Tevatron Collider and corresponds to approximately 250 pb(-1) of integrated luminosity at root s=1.96 TeV. Under the assumption that the WW gamma couplings are equal to the WWZ couplings and using a form factor scale of Lambda=2.0 TeV, the combined 95% C.L. one-dimensional coupling limits from all three channels are -0.32 <Delta kappa < 0.45 and -0.29 <lambda < 0.30.
Footprints of a left-right symmetric model in a muon collider
2000
Abstract The double charged Higgs bosons, Δ ±± , are one of the benchmarks of left-right symmetric models. We discuss their production and demonstrate that even for small values of the Δ ++ l − l − coupling, they would produce observable signals at muon colliders.
A large Streamer Chamber muon tracking detector in a high-flux fixed-target application.
1999
Arrays of limited streamer tubes of the Iarocci type were deployed in our experiment at CERN as part of a forward muon detector system with provisions for the beam to pass through the center of each panel in the array. A total of 16 4 m x 4 m panels were assembled with inductive readout strips on both sides of each panel. An active feedback system. was deployed to regulate the high voltage to the streamer tubes to insure a constant efficiency for minimum ionizing particles. The arrays were operated in this environment for over five years of data taking. Streamer tube track-reconstruction efficiencies and tube replacement rates are reported. (C) 1999 Elsevier Science B.V. All rights reserved.
Optimal filtering algorithm implementation in FPGAs for the ATLAS TileCal Read-Out drivers
2011
TileCal is the hadronic calorimeter of the ATLAS experiment in the LHC (CERN). Its Read-Out Drivers (RODs) process, in real time, the digitized information coming from the front-end electronics and send it to the Read-Out System. Data processing in the ROD boards is performed in Processing Unit Mezzanine Cards that use commercial DSPs to run the Optimal Filtering (OF) algorithms.
Implementation and Performance of the Signal Reconstruction in the ATLAS Hadronic Tile Calorimeter
2012
AbstractThe Tile Calorimeter (TileCal) for the ATLAS experiment at the CERN Large Hadron Collider (LHC) is currently taking data with proton-proton collisions. The Tile Calorimeter is a sampling calorimeter with steel as absorber and scintillators as active medium. The scintillators are read-out by wavelength shifting fibers coupled to photomultiplier tubes (PMT). The analogue signals from the PMTs are amplified, shaped and digitized by sampling the signal every 25ns. The TileCal front-end electronics allows to read-out the signals produced by about 10000 channels measuring energies ranging from ∼30 MeV to ∼2 TeV. The read-out system is designed to reconstruct the data in real-time fulfilli…
The ATLAS TileCal read-out drivers signal reconstruction
2009
TileCal is the hadronic calorimeter of the ATLAS experiment at the LHC collider at CERN. The Read-Out Drivers (ROD) are the core of the off-detector electronics. The main components of the RODs are the Digital Signal Processor (DSP) placed on the Processing Unit (PU) dautherboards. This paper describes the DSP code and its performance with calibration and real data. The code is divided into two different parts: the first part contains the core functionalities and the second one the reconstruction algorithms. The core acts as an operating system and it controls the configuration, the data reception, transmission, online monitoring and the synchronization between front-end data and the Trigge…
The UA4/2 experiment at the CERN SpS collider
1997
Abstract The UA4/2 experiment performed at CERN to measure the ratio of the real to the imaginary part of the forward elastic scattering amplitude is described. The accent is placed on the improvements with respect to the previous UA4 experiment, especially on the much improved design of the high-β insertion and a high-resolution, highly multiplexed scintillating fiber tracking detector.