Beta asymmetry parameter in the decay of 114In

The beta asymmetry parameter A for the pure Gamow-Teller decay of 114In is reported. The low temperature nuclear orientation method was combined with a GEANT4 based simulation code allowing for the first time to address in detail the effects of scattering and of the magnetic field. The result, A = -0.994 +/- 0.010stat +/- 0.010syst, constitutes the most accurate value for the asymmetry parameter of a nuclear beta transition to date. The value is in agreement with the Standard Model prediction of A = -1 and provides new limits on tensor type charged weak currents.Comment: 11 pages, 2 figures; additional information was added on systematic effects, the magnetic field map and the calculation of the Qcos(theta) value

Performance of Geant4 in simulating semiconductor particle detector response in the energy range below 1 MeV

Geant4 simulations play a crucial role in the analysis and interpretation of experiments providing low energy precision tests of the Standard Model. This paper focuses on the accuracy of the description of the electron processes in the energy range between 100 and 1000 keV. The effect of the different simulation parameters and multiple scattering models on the backscattering coefficients is investigated. Simulations of the response of HPGe and passivated implanted planar Si detectors to \beta{} particles are compared to experimental results. An overall good agreement is found between Geant4 simulations and experimental data

Seasonal and site-specific variation in vapour and aerosol phase PAHs over Flanders (Belgium) and their relation with anthropogenic activities

Peer reviewe

The impact of urbanisation on chipmunks, arboreal and flying squirrels: a global systematic review

The current, rapid urbanisation process impacts global biodiversity and can be a driver for phenotypic changes in mammals that persist in cities. Animals display different response strategies in urban environments compared to natural areas, but patterns may differ among species. To better comprehend this process, we focused on a limited number of species that are present in many urban green spaces around the globe.The aim of this systematic review is to investigate which response strategies chipmunks, arboreal and flying squirrels use to cope with urban environments, exploring whether there are general response patterns, and to reveal potential adaptations to life in urban areas. We included studies that compared trait differences among conspecifics living in different areas along an urbanisation gradient (rural-urban) and studies comparing individuals or populations between urban areas with different environmental characteristics.The effects of urbanisation on chipmunks, arboreal and flying squirrels, at the individual and at the population levels, were identified in nine topics. Included articles explored at least one of these topics and their key findings were described.Effects of urbanisation are evident in all considered topics. However, we found contrasting patterns between species or even among individuals of the same species studied in different geographical areas. Overall, we reported two knowledge gaps: some phenotypic traits were considered in few studies, and many species, especially those living in the Global South, where urban growth rate is higher, have not been studied.This systematic review suggests that urbanisation can be an important driver for adaptation in small mammals, underlining the complexity and differentiation of response patterns. Since target species have important ecological and social roles, additional comparative studies, increasing our understanding of processes that determine their presence in cities, are essential for urban green planning which aims to conserve biodiversity

First detection and energy measurement of recoil ions following beta decay in a Penning trap with the WITCH experiment

The WITCH experiment (Weak Interaction Trap for CHarged particles) will search for exotic interactions by investigating the beta-neutrino angular correlation via the measurement of the recoil energy spectrum after beta decay. As a first step the recoil ions from the beta-minus decay of 124In stored in a Penning trap have been detected. The evidence for the detection of recoil ions is shown and the properties of the ion cloud that forms the radioactive source for the experiment in the Penning trap are presented.Comment: 9 pages, 6 figures (9 figure files), submitted to European Physical Journal

The MuPix Telescope: A Thin, high Rate Tracking Telescope

The MuPix Telescope is a particle tracking telescope, optimized for tracking low momentum particles and 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 data self-triggered 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.Comment: Proceedings TWEPP 2016, 8 pages, 7 figure