Recent CMS results related to jet production measurements as well as measurements of the strong coupling constant are discussed. In particular, results are described related to jet production cross ...sections, which pose a central test to perturbative QCD predictions, as well as hadronic event shape measurements, and measurements of αS with data taken at center-of-mass energy of 7 TeV and 8 TeV collected with the CMS detector.
We present the meta-crystals concept, an approach that consists of using both undoped and properly doped heavy crystal fibers of identical material as the active medium of a calorimeter. The undoped ...fibers behave as Cherenkov radiators while the doped ones behave as scintillators. A dual readout calorimeter can be built with its sensitive volume composed of a mixture of both types of crystals. In addition if the calorimeter is adequately finely segmented it can also function as a particle flow calorimeter at the same time. In this way one could possibly combine the advantages of both the particle flow concept and the dual-readout scheme. We discuss the approach of dual readout calorimetry with meta-crystals made of Lutetium Aluminium Garnet (LuAG) and present studies on the material development, first testbeam activities and results based on simulation for understanding the performance trends. We close with a brief outlook on open issues and further R&D needed to proceed from an ideal conceptual case to the design of a realistic detector.
Tests of a Digital Hadron Calorimeter Bilki, Burak; Butler, John; May, Ed ...
Journal of physics. Conference series,
04/2011, Letnik:
293, Številka:
1
Journal Article
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Odprti dostop
In the context of developing a hadron calorimeter with extremely fine granularity for the application of Particle Flow Algorithms to the measurement of jet energies at a future lepton collider, we ...report on extensive tests of a small scale prototype calorimeter. The calorimeter contained up to 10 layers of Resistive Plate Chambers (RPCs) with 2560 1×1 cm2 readout pads, interleaved with steel absorber plates. The tests included both long-term Cosmic Ray data taking and measurements in particle beams, where the response to broadband muons and to pions and positrons with energies in the range of 1 – 16 GeV was established. Detailed measurements of the chambers efficiency as function of beam intensity have also been performed using 120 GeV protons at varying intensity. The data are compared to simulations based on GEANT4 and to analytical calculations of the rate limitations.
The meta-crystals concept is an approach that consists of using both undoped and properly doped heavy crystal fibers of identical material as the active medium of a calorimeter. The undoped fibers ...behave as Cherenkov radiators while the doped ones behave as scintillators. A dual readout calorimeter can be built with its sensitive volume composed of a mixture of both types of crystals. In addition if the calorimeter is adequately finely segmented it can also function as a particle flow calorimeter at the same time. In this way one could possibly combine the advantages of both the particle flow concept and the dual-readout scheme. We discuss the approach of dual readout calorimetry with meta-crystals made of Lutetium Aluminium Garnet (LuAG). We briefly present studies on the material development and first testbeam activities and then focus on performance expectation studies based on simulation. We discuss in more detail the results from generic systematic scannings of the design parameters of a dual readout calorimeter. The design parameters under study include transverse and longitudinal granularity, sampling frequency/readout fraction of the scintillation/ionisation and the Cherenkov signals, total length of calorimeter, mixture of homogeneous and sampling dual readout components, corresponding composition etc. We close with a brief outlook on open issues and further R&D needed to proceed from an ideal conceptual case to the design of a realistic detector.
In the context of developing a hadron calorimeter with extremely fine granularity for the application of Particle Flow Algorithms to the measurement of jet energies at a future lepton collider, we ...report on extensive tests of a small scale prototype calorimeter. The calorimeter contained up to 10 layers of Resistive Plate Chambers (RPCs) with 2560 1 \times 1 cm2 readout pads, interleaved with steel absorber plates. The tests included both long-term Cosmic Ray data taking and measurements in particle beams, where the response to broadband muons and to pions and positrons with energies in the range of 1 - 16 GeV was established. Detailed measurements of the chambers efficiency as function of beam intensity have also been performed using 120 GeV protons at varying intensity. The data are compared to simulations based on GEANT4 and to analytical calculations of the rate limitations.
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