supported by

Collaborative Research Centre 16

Subnuclear Structure of Matter

Project overview

Hadron properties

Project area A deals with the spectroscopy of baryon resonances. Double polarization experiments are performed to unravel the properties of the pertinent resonances. These data are further investigated in a dedicated multi-channel partial wave analysis together with many other available data sets. These investigations are complemented by theoretical studies using large-Nc QCD, finite volume effective field theories and various functional methods.

Hadron dynamics

Project area B deals with the photoproduction of mesons to unravel the underlying production dy-
namics. Recoil polarization measurements will be performed as an important ingredient towards a
complete experiment. This is complemented by studies of in-medium properties of vector and heavy
pseudoscalar mesons. On the theoretical side, effective field theories are used to study meson decays
as well as resonance excitations in chiral unitary approaches. A dedicated coupled channel partial
wave analysis of photo- and hadro- induced meson production is also performed. Furthermore, the
extraction of neutron properties from light nuclei is studied.

Hadron structure

Project area C is devoted to a study of QCD-dynamics of pseudoscalar and vector mesons and their
decays. Properties of flavor singlet pseudoscalar mesons are calculated using lattice QCD. In addition,
chiral effective field theories of and with instable particles are developed.

Instrumentation

Project area D deals with polarized target, detector and accelerator physics. A new “4π-continuous mode” target will be finalized and new target materials will be developed. Research on accelerator physics will lead to enhanced beam polarization, intensity and quality. An installation of a new APD- readout of the Crystal Barrel calorimeter will significantly improve the timing and tracking possibilities for the Crystal Barrel/TAPS set-up. The projects will benefit the double polarization experiments considerably and in addition pave the way to double polarization measurements off the neutron.