Projects attempting the direct detection of WIMP dark matter share the common problem of eliminating sources of background or using techniques to distinguish background events from true signals. ...Although experiments such as DarkSide have achieved essentially background free exposures through careful choice of materials and application of efficient veto techniques, there will still be a high burden of proof to convince the greater scientific community when a discovery is claimed. A directional signature in the data would provide extremely strong evidence to distinguish a true WIMP signal from that of an isotropic background. Two-phase argon time projection chambers (TPCs) provide an experimental apparatus which can both be scaled to the ton-scale size required to accommodate the low cross-section expected for WIMP interactions and have an anisotropy that could be exploited to evaluate the polar angles of the resulting nuclear recoils from WIMP collisions with target nuclei. Our studies show that even a modest resolution in the polar angle reconstruction would offer a powerful tool to detect a directional signature. In this contribution, the status of the ReD experiment, which is under construction at Naples University, will be also shown. The aim of the project is to assess and enhance the directionality of two-phase argon TPCs. ReD will use a small TPC exposed to a beam of mono-energetic neutrons to study the so called “columnar recombination” in liquid argon. This development could have high impact on the future experiments in the field, opening up the potential to find conclusive evidence for dark matter or disprove the WIMP hypothesis at and above the mass range explored by planned accelerator experiments.
This correction provides updated acknowledgements:
This work was supported by Istituto Nazionale di Fisica Nucleare; the Swiss National Science Foundation Ambizione Grant (No. 154833); a Deutsche ...Forschungsgemeinschaft research grant; an excellence initiative of Heidelberg University; Marie Sklodowska-Curie Innovative Training Network Fellowship of the European Commission’s Horizon 2020 Programme (No. 721559 AVA); European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement ANGRAM No 748826; European Research Council under the European Union’s Seventh Framework Program FP7/2007-2013 (Grants Nos. 291242 and 277762); Austrian Ministry for Science, Research, and Economy; Research Council of Norway; Bergen Research Foundation; John Templeton Foundation; Ministry of Education and Science of the Russian Federation and Russian Academy of Sciences; and the European Social Fund within the framework of realizing the project, in support of intersectoral mobility and quality enhancement of research teams at Czech Technical University in Prague (Grant No. CZ.1.07/2.3.00/30.0034).
This correction provides updated acknowledgements:This work was supported by Istituto Nazionale di Fisica Nucleare; the Swiss National Science Foundation Ambizione Grant (No. 154833); a Deutsche ...Forschungsgemeinschaft research grant; an excellence initiative of Heidelberg University; Marie Sklodowska-Curie Innovative Training Network Fellowship of the European Commission’s Horizon 2020 Programme (No. 721559 AVA); European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement ANGRAM No 748826; European Research Council under the European Union’s Seventh Framework Program FP7/2007-2013 (Grants Nos. 291242 and 277762); Austrian Ministry for Science, Research, and Economy; Research Council of Norway; Bergen Research Foundation; John Templeton Foundation; Ministry of Education and Science of the Russian Federation and Russian Academy of Sciences; and the European Social Fund within the framework of realizing the project, in support of intersectoral mobility and quality enhancement of research teams at Czech Technical University in Prague (Grant No. CZ.1.07/2.3.00/30.0034).
The AEgIS experiment aims at producing antihydrogen (and eventually measuring the effects of the Earth gravitational field on it) with a method based on the charge exchange reaction between ...antiproton and Rydberg positronium. To be precise, antiprotons are delivered by the CERN Antiproton Decelerator (AD) and are trapped in a multi-ring Penning trap, while positronium is produced by a nanoporous silica target and is excited to Rydberg states by means of a two steps laser excitation. New Monte Carlo simulations are presented in this paper in order to investigate the current status of the AEgIS experiment
1
and to interpret the recently collected data
2
.
AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is an experiment that aims to perform the first direct measurement of the gravitational acceleration g of antihydrogen in the ...Earth’s field. A cold antihydrogen beam will be produced by charge exchange reaction between cold antiprotons and positronium excited in Rydberg states. Rydberg positronium (with quantum number
n
between 20 and 30) will be produced by a two steps laser excitation. The antihydrogen beam, after being accelerated by Stark effect, will fly through the gratings of a moiré deflectometer. The deflection of the horizontal beam due to its free fall will be measured by a position sensitive detector. It is estimated that the detection of about 10
3
antihydrogen atoms is required to determine the gravitational acceleration with a precision of 1%. In this report an overview of the AEgIS experiment is presented and its current status is described. Details on the production of slow positronium and its excitation with lasers are discussed.
PDF
