As high energy physics experiments reach higher luminosities and intensities, the computing burden for real time data processing and reduction grows. Following the developments in the computing ...landscape, multi-core processors such as graphics processing units (GPUs) are increasingly used for such tasks. These proceedings provide an introduction to the GPU architecture and describe how it maps to common tasks in real time data processing. In addition, specific use cases of GPUs in the trigger systems of five different high energy physics experiments are presented.
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, Volume:
1014
Journal Article
Peer reviewed
Open access
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.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the present work of the PIENU experiment, heavy neutrinos were sought in pion decays π+→μ+ν at rest by examining the observed muon energy spectrum for extra peaks in addition to the expected peak ...for a light neutrino. No evidence for heavy neutrinos was observed. Upper limits were set on the neutrino mixing matrix |Uμi|2 in the neutrino mass region of 15.7–33.8 MeV/c2, improving on previous results by an order of magnitude.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A search for massive neutrinos has been made in the decay π+→e+ν. No evidence was found for extra peaks in the positron energy spectrum indicative of pion decays involving massive neutrinos (π→e+νh). ...Upper limits (90% C.L.) on the neutrino mixing matrix element |Uei|2 in the neutrino mass region 60–135 MeV/c2 were set and are an order of magnitude improvement over previous results.
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A new measurement of the branching ratio R_{e/μ}=Γ(π^{+}→e^{+}ν+π^{+}→e^{+}νγ)/Γ(π^{+}→μ^{+}ν+π^{+}→μ^{+}νγ) resulted in R_{e/μ}^{exp}=1.2344±0.0023(stat)±0.0019(syst)×10^{-4}. This is in agreement ...with the standard model prediction and improves the test of electron-muon universality to the level of 0.1%.
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The MuPix Telescope is a particle tracking telescope, optimized for tracking low momentum particles at high rates. It is based on the novel High-Voltage Monolithic Active Pixel Sensors (HV-MAPS), ...designed for the Mu3e tracking detector. The telescope represents a first application of the HV-MAPS technology and also serves as test bed of the Mu3e readout chain. The telescope consists of up to eight layers of the newest prototypes, the MuPix7 sensors, which send self-triggered data via fast serial links to FPGAs, where the data is time-ordered and sent to the PC. A particle hit rate of 1 MHz per layer could be processed. Online tracking is performed with a subset of the incoming data. The general concept of the telescope, chip architecture, readout concept and online reconstruction are described. The performance of the sensor and of the telescope during test beam measurements are presented.
The three body pion decays ... where X is a weakly interacting neutral boson, were searched for using the full data set from the PIENU experiment. An improved limit on ... in the mass range ... and a ...first result for ... in the region ... were obtained. The Majoron-neutrino coupling model was also constrained using the current experimental result of the ... branching ratio.(ProQuest: ... denotes formulae omitted.)
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A search for direct CP violation in the Cabibbo-suppressed decay D-s(+) -> K-K+ K+ and in the doubly Cabibbo-suppressed decay D+ -> K- K+ K+ is reported. The analysis is performed with data ...collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of 13TeV corresponding to an integrated luminosity of 5.6 fb(-1). The search is conducted by comparing the D-(s)(+) and D-(s)(-) Dalitz-plot distributions through a model-independent binned technique, based on fits to the K-K+K+ invariantmass distributions, with a total of 0.97 (1.27) million D-s(+) (D+) signal candidates. The results are given as p-values for the hypothesis of CP conservation and are found to be 13.3% for the D+ -> K-K+ K+ decay and 31.6% for the D+ -> K-K+ K+ decay. No evidence for CP violation is observed in these decays.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Charged lepton flavor violating muon decay μ+ → e+XH, where XH is a massive neutral boson, was sought by searching for extra peaks in the muon decay μ+ → e+ν¯ν energy spectrum in the mXH mass region ...47.8–95.1 MeV/c2. No signal was found and 90% confidence level upper limits were set on the branching ratio Γ(μ+ → e+XH)/Γ(μ+ → e+ν¯ν) at the level of 10−5 for this region.
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The pion branching ratio,
R
π
=
Γ
(
π
+
→
e
+
ν
e
+
π
+
→
e
+
ν
e
γ
)
Γ
(
π
+
→
μ
+
ν
μ
+
π
+
→
μ
+
ν
μ
γ
)
, provides a sensitive test of lepton universality and constraints on many new physics ...scenarios. The theoretical uncertainty on the Standard Model prediction of
R
π
is 0.02 %, a factor of twenty smaller than the experimental uncertainty. The analysis of a subset of data taken by the PIENU experiment will be presented. The result,
R
π
= (1.2344 ± 0.0023(
s
t
a
t
) ± 0.0019(
s
y
s
t
)) ⋅ 10
−4
1
, is consistent with the Standard Model prediction and represents a 0.1 % constraint on lepton non-universality.
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