Search results for "Positron energy"

showing 2 items of 2 documents

Improved search for heavy neutrinos in the decay π→eν

2018

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.

PhysicsPhysics::Instrumentation and Detectors010308 nuclear & particles physicsAstrophysics::High Energy Astrophysical PhenomenaHigh Energy Physics::PhenomenologySpectrum (functional analysis)Pontecorvo–Maki–Nakagawa–Sakata matrix01 natural sciencesSpectral linePositron energyNuclear physicsPion0103 physical sciencesHigh Energy Physics::ExperimentInvariant massNeutrino010306 general physicsOrder of magnitudePhysical Review D
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Image quality analysis of

2019

Background 44Sc has been increasingly investigated as a potential alternative to 68Ga in the development of tracers for positron emission tomography (PET). The lower mean positron energy of 44Sc (0.63 MeV) compared to 68Ga (0.83 MeV) can result in better spatial image resolutions. However, high-energy γ-rays (1157 keV) are emitted at high rates (99.9%) during 44Sc decay, which can reduce image quality. Therefore, we investigated the impact of these physical properties and performed an unbiased performance evaluation of 44Sc and 68Ga with different imaging phantoms (image quality phantom, Derenzo phantom, and three-rod phantom) on two preclinical PET scanners (Mediso nanoScan PET/MRI, Siemen…

Positron rangeSmall animal PETImage qualityPositron energyPhantom studyScandium-44ResolutionOriginal ResearchEJNMMI physics
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