A spectrometer for the measurement of anomalies in angular correlation of electrons and positrons internally produced in excited 8Be and 4He
Hugo Natal da Luz
Institute of Experimental and Applied Physics, CTU in Prague
Abstract: Recent studies on excited states of 8Be and 4He show large discrepancies from the theoretical expectation in the emission angle of electron-positron pairs from Internal Pair Production. According to the Standard Model, the angular distribution should peak at 0° and decrease monotonically with increasing angles. However, measurements carried out at ATOMKI, in Debrecen, Hungary, have shown extra structures in those distributions in the form of peaks around 140° in 8Be and 115° in 4He. These effects can be explained by a new boson with a mass around 17 MeV, commonly referred as X17.
Different research groups are trying to repeat the measurements either to confirm or disprove this effect. The measurements must be done with systems of different types of detectors, to guarantee better angular and energy resolution. A higher precision will provide a better knowledge of the properties of the X17.
In this seminar, after some context on experimental setup and the instrumentation related to the measurements in the emission of electron-positron pairs, including those proposed by other labs, I will describe the spectrometer under construction in the IEAP, that is expected to provide increased precision in the measurements. The spectrometer will be based in Time Projection Chambers under a magnetic field for the energy measurements and in thin Timepix3 detectors inside the vacuum tube, followed by Multiwire Proportional Counters in the gas volume for angular measurements.
Seminar takes place on Tuesday, June 16th 2020 at 2:00 PM
in the IEAP meeting room, Praha 1, Husova 240/5.
| Ing. Bartoloměj Biskup, Ph.D. seminar organizer |
doc. Ing. Ivan Štekl, CSc. director of IEAP |
doc. Dr. André Sopczak IEEE CS - NPSS chair |
NUCLEAR & PLASMA SCIENCES SOCIETY CHAPTER
IEEE Czechoslovakia section
http://www.ieee.cz/en/nps
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