1,663 research outputs found
Commissioning of CMS Forward Hadron Calorimeters with Upgraded Multi-anode PMTs and {\mu}TCA Readout
The high flux of charged particles interacting with the CMS Forward Hadron
Calorimeter PMT windows introduced a significant background for the trigger and
offline data analysis. During Long Shutdown 1, all of the original PMTs were
replaced with multi-anode, thin window photomultiplier tubes. At the same time,
the back-end electronic readout system was upgraded to {\mu}TCA readout. The
experience with commissioning and calibration of the Forward Hadron Calorimeter
is described as well as the {\mu}TCA system. The upgrade was successful and
provided quality data for Run 2 data-analysis at 13 TeV
SNOWMASS WHITE PAPER - SLHC Endcap 1.4<y<4 Hadron Optical Calorimetry Upgrades in CMS with Applications to NLC/T-LEP, Intensity Frontier, and Beyond
Radiation damage in the plastic scintillator and/or readout WLS fibers in the
HE endcap calorimeter 1.4<y<4 in the CMS experiment at LHC and SLHC will
require remediation after 2018. We describe one alternative using the existing
brass absorber in the Endcap calorimeter, to replace the plastic scintillator
tiles with BaF2 tiles, or quartz tiles coated with thin(1-5 micron) films of
radiation-hard pTerphenyl(pTP) or the fast phosphor ZnO:Ga. These tiles would
be read-out by easily replaceable arrays of straight, parallel WLS fibers
coupled to clear plastic-cladded quartz fibers of proven radiation resistance.
We describe a second alternative with a new absorber matrix extending to
1.4<y<4 in a novel Analog Particle Flow Cerenkov Compensated Calorimeter, using
a dual readout of quartz tiles and scintillating (plastic, BaF2, or pTP/ ZnO:Ga
thin film coated quartz, or liquid scintillator) tiles, also using easily
replaceable arrays of parallel WLS fibers coupled to clear quartz transmitting
fibers for readout. An Analog Particle Flow Scintillator-Cerenkov Compensated
Calorimeter has application in NLC/T-LEP detectors and Intensity Frontier
detectors
Snowmass White Paper CMS Upgrade: Forward Lepton-Photon System
This White Paper outlines a proposal for an upgraded forward region to extend
CMS lepton (e, mu) and photon physics reach out to 2.2<eta<5 for LHC and SLHC,
which also provides better performance for the existing or new forward hadron
calorimetry for jet energy and (eta, phi) measurements, especially under
pileup/overlaps at high lumi, as LHC luminosity, energy and radiation damage
increases
CMS HCAL Installation and Commissioning
The installation and commissioning of the Hadron Calorimeter system of the CMS detector is described and the performance of the various monitoring systems, the progress in the calibration work and the current plans for the HCAL calorimeter are summarized
Total Absorption Dual Readout Calorimetry R&D
Abstract This calorimetry R&D focuses on establishing a proof of concept for totally active hadron calorimetry. The research program involves evaluating the performance of the different crystal and glass samples in combination with different light collection and readout alternatives to optimize simultaneous collection of Cerenkov and scintillation light components for application of the Dual Readout technique to total absorption calorimetry. We performed initial studies in two short test beam phases in April and November 2010 at Fermilab. Here we present first measurements from these two beam tests
High Order QCD Predictions for Inclusive Production of W
Predictions of fiducial cross sections, differential cross sections, and lepton charge asymmetry are presented for the production of W± bosons with leptonic decay up to next-to-next-to-leading order (NNLO) in perturbative QCD. Differential cross sections of W± bosons and W boson lepton charge asymmetry are computed as a function of lepton pseudorapidity for a defined fiducial region in pp collisions at s=13 TeV. Numerical results of fiducial W± cross section predictions are presented with the latest modern PDF models at next-to-leading order (NLO) and NNLO. It is found that the CT14 and NNPDF 3.0 predictions with NNLO QCD corrections are about 4% higher than the NLO CT14 and NNPDF 3.0 predictions while MMHT 2014 predictions with NLO QCD corrections are smaller than its NNLO QCD predictions by approximately 6%. In addition, the NNLO QCD corrections reduce the scale variation uncertainty on the cross section by a factor of 3.5. The prediction of central values and considered uncertainties are obtained using FEWZ 3.1 program
Beam Test Results of the RADiCAL -- a Radiation Hard Innovative EM Calorimeter
High performance calorimetry conducted at future hadron colliders, such as
the FCC-hh, poses a significant challenge for applying current detector
technologies due to unprecedented beam luminosities and radiation fields.
Solutions include developing scintillators that are capable of separating
events at the sub-fifty picosecond level while also maintaining performance
after extreme and constant neutron and ionizing radiation exposure. The RADiCAL
is an approach that incorporates radiation tolerant materials in a sampling
'shashlik' style calorimeter configuration, using quartz capillaries filled
with organic liquid or polymer-based wavelength shifters embedded in layers of
tungsten plates and LYSO crystals. This novel design intends to address the
Priority Research Directions (PRD) for calorimetry listed in the DOE Basic
Research Needs (BRN) workshop for HEP Instrumentation. Here we report
preliminary results from an experimental run at the Fermilab Test Beam Facility
in June 2022. These tests demonstrate that the RADiCAL concept is capable of <
50 ps timing resolution.Comment: 5 pages, 10 figures, SCINT22 conferenc
Status of Muon Collider Research and Development and Future Plans
The status of the research on muon colliders is discussed and plans are
outlined for future theoretical and experimental studies. Besides continued
work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy
collider, many studies are now concentrating on a machine near 0.1 TeV (CoM)
that could be a factory for the s-channel production of Higgs particles. We
discuss the research on the various components in such muon colliders, starting
from the proton accelerator needed to generate pions from a heavy-Z target and
proceeding through the phase rotation and decay ()
channel, muon cooling, acceleration, storage in a collider ring and the
collider detector. We also present theoretical and experimental R & D plans for
the next several years that should lead to a better understanding of the design
and feasibility issues for all of the components. This report is an update of
the progress on the R & D since the Feasibility Study of Muon Colliders
presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A.
Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics
(Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics,
Accelerators and Beam
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