München 2019 – wissenschaftliches Programm
HK 47.3: Vortrag
Donnerstag, 21. März 2019, 14:45–15:00, HS 13
η′ beam asymmetry at threshold using the BGO-OD experiment — •Stefan Alef for the BGO-OD collaboration — Physikalisches Institut Universität Bonn
The unexpected nodal structure of the beam asymmetry recently reported by the GRAAL collaboration in η′ photoproduction very close to threshold could be explained by a previously unobserved very narrow
resonance. Therefor, the measurement is important to be independently confirmed.
This possibility is offered by the BGO-OD experiment. It is well suited for the detection of forward going charged particles which in the threshold region of interest allows the identification of the reaction γ p → η′ p solely based on the proton going in forward direction. This yields unprecedented statistics if in the missing mass analysis of the η′ meson the background can be sufficiently well controlled. A linearly polarized photon beam produced via coherent bremsstrahlung off a diamond radiator makes it possible to measure the η′ beam asymmetry.
In this talk I will present preliminary results on the determination of the η′ beam asymmetry in several energy and angular bins close to threshold.
Supported by DFG (PN 50165297).