Technical design of the phase I Mu3e experiment Arndt, K.; Augustin, H.; Baesso, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2021, Letnik:
1014
Journal Article
Recenzirano
Odprti dostop
The Mu3e experiment aims to find or exclude the lepton flavour violating decay μ→eee at branching fractions above 10−16. A first phase of the experiment using an existing beamline at the Paul ...Scherrer Institute (PSI) is designed to reach a single event sensitivity of 2⋅10−15. We present an overview of all aspects of the technical design and expected performance of the phase I Mu3e detector. The high rate of up to 108 muon decays per second and the low momenta of the decay electrons and positrons pose a unique set of challenges, which we tackle using an ultra thin tracking detector based on high-voltage monolithic active pixel sensors combined with scintillating fibres and tiles for precise timing measurements.
The RD53A is a prototype of the readout chip that will be used in the Compact Muon Solenoid (CMS) pixel detector after the High-Lumi LHC (HL-LHC) upgrade is complete beyond 2025. A new feature of the ...chip enables the writing of configuration commands between triggers during operation. This feature can be used to compensate for a detuning of the pixels due to radiation damage or temperature fluctuations over time. This paper studies the efficiency of such a method as well as its side-effects and the dependency on its parameters using an equivalent software implementation.
Lutetium-Yttrium Orthosilicate doped with Cerium (LYSO), as a bright scintillating crystal, is a candidate for calorimetry applications in strong ionising-radiation fields and large high-energy ...hadron fluences are expected at the CERN Large Hadron Collider after the planned High-Luminosity upgrade. There, proton–proton collisions will produce fast hadron fluences up to ~5×1014cm−2 in the large-rapidity regions of the calorimeters.
The performance of LYSO has been investigated, after exposure to different fluences of 24GeVc−1 protons. Measured changes in optical transmission as a function of proton fluence are presented, and the evolution over time due to spontaneous recovery at room temperature is studied.
The activation of materials will also be an issue in the described environment. Studies of the ambient dose induced by LYSO and its evolution with time, in comparison with other scintillating crystals, have also been performed through measurements and FLUKA simulations.
A measurement of the inclusive deep inelastic neutral current
e
+
p
scattering cross section is reported in the region of four-momentum transfer squared, 12 GeV
2
≤
Q
2
≤150 GeV
2
, and Bjorken
x
, ...2×10
−4
≤
x
≤0.1. The results are based on data collected by the H1 Collaboration at the
ep
collider HERA at positron and proton beam energies of
E
e
=27.6 GeV and
E
p
=920 GeV, respectively. The data are combined with previously published data, taken at
E
p
=820 GeV. The accuracy of the combined measurement is typically in the range of 1.3–2%. A QCD analysis at next-to-leading order is performed to determine the parton distributions in the proton based on H1 data.
The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the ...Tevatron delivered 12fb−1 of integrated luminosity of pp¯ collisions at s=1.96TeV. The physics at CDF includes precise measurements of the masses of the top quark and W boson, measurement of CP violation and Bs mixing, and searches for Higgs bosons and new physics signatures, all of which require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2–5 years of operation, radiation doses up to 2Mrad (0.02Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, and the improvements made along the way to ensure their optimal performance for collecting high quality physics data. In addition, we describe the quantities and methods used to monitor radiation damage in the sensors for optimal performance and summarize the detector performance quantities important to CDF's physics program, including vertex resolution, heavy flavor tagging, and silicon vertex trigger performance.
•We have operated the CDF II silicon detector system well beyond its design lifetime.•We describe design of each component, its performance parameters and resource needs.•A history of operational experience and mitigation of encountered problems is given.•Novel methods were found to mitigate wirebond resonance and cooling system corrosion.•Radiation aging effects on silicon sensors from a decade long exposure are presented.
The anticipated performance of calorimeter crystals in the environment expected after the planned High-Luminosity upgrade of the Large Hadron Collider (HL-LHC) at CERN has to be well understood, ...before informed decisions can be made on the need for detector upgrades. Throughout the years of running at the HL-LHC, the detectors will be exposed to considerable fluences of fast hadrons that have been shown to cause cumulative transparency losses in Lead Tungstate scintillating crystals. In this study, we present direct evidence of the main underlying damage mechanism. Results are shown from a test that yields a direct insight into the nature of the hadron-specific damage in Lead Tungstate calorimeter crystals exposed to 24GeV/c protons.
Diamond pixel modules Asner, D.; Barbero, M.; Bellini, V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2011, Letnik:
636, Številka:
1
Journal Article
Recenzirano
With the commissioning of the LHC in 2010 and upgrades expected in 2015, ATLAS and CMS are planning to upgrade their innermost tracking layers with radiation hard technologies. Chemical Vapor ...Deposition diamond has been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of BaBar, Belle, CDF and all LHC experiments. This material is now being considered as a sensor material for use very close to the interaction region where the most extreme radiation conditions exist. Recently the RD42 collaboration constructed, irradiated and tested polycrystalline and single-crystal chemical vapor deposition diamond sensors to the highest fluences expected at the super-LHC. We present beam test results of chemical vapor deposition diamond up to fluences of 1.8×10
16
protons/cm
2 illustrating that both polycrystalline and single-crystal chemical vapor deposition diamonds follow a single damage curve. We also present beam test results of irradiated complete diamond pixel modules.
Single top production at CDF Wallny, R
Journal of physics. Conference series,
05/2008, Letnik:
110, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The CDF Collaboration has analyzed 955 pb-1 of CDF II data collected between March 2002 and February 2006 to search for electroweak single top quark production at the Tevatron. We employ three ...different analysis techniques to search for a single top signal: multivariate likelihood functions; neural networks; the matrix element analysis technique. The sensitivities to a single top signal at the rate predicted by the Standard Model are 2.1 σ, 2.6 σ and 2.5 σ, respectively. The first two analyses observe a deficit of single top-like events and set upper limits on the production cross section. The matrix element analysis observes a 2.3 σ single top excess and measures a combined t-channel and s-channel cross section of 2.7-1.3+1.5pb.
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