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Seminars in Physics and Astronomy

Measuring di-electron Dalitz decays of baryon resonances with HADES and PANDA

by Jacek Biernat (Uppsala University)

Thursday, 18 January 2018 from to (Europe/Stockholm)
at Å12167
Description

Abstract:

The first part of the talk will be devoted to the investigation of di-electron pair production in quasi-free n – p interactions using deuterium beams on proton target at kinetic energy of 1.25GeV/u . Detection of spectator proton from deuterium breakup at forward angles (0.3◦ < θ < 7◦) and electron-positron pairs and proton in High Acceptance Dielectron Spectrometer (HADES) located at GSI allows for detailed analysis of the exclusive pair production in the n – p → np e+ e - reaction. Obtained exclusive distributions will be compared to the corresponding one obtained from pp collisions at the same energy. The results will be compared with predictions obtained from available calculations. In particular interpretations of a striking difference in the pair production in both reactions will be discussed. Hence providing an explanation in the e+ e - pair production difference observed in the previous inclusive analysis.

The second part will be focused on  a proposal of measurement of electromagnetic Hyperon Decays (Hyperon -> Lambda e+e-) for the future experiment PANDA@GSI will be presented. The example of on Lambda(1520) Dalitz decay in to e+ e- will be presented. Studying the signal form this channel gives the possibility of probing the eFF (Electromagnetic Form Factors) which carry information about hadron structure. The main focus of the seminar is to present details of a simulation of the  Lambda(1520) Dalitz decay in to a pair e+ e-  produced via pbar-p collision at 4 GeV/c,  its reconstruction and detection in the PANDA detector and finally an estimation of the production rate and signal to background rate had been performed.
The results will be compared with similar simulations done for HADES experiment also
proposed to study such transitions but in pp collisions.