44 research outputs found
Mesons in Nuclei: eta and omega mesons
Data on the photoproduction of omega mesons on nuclei have been re-analyzed
in search for in-medium modifications. The data were taken with the Crystal
Barrel(CB)/TAPS detector system at the ELSA accelerator facility in Bonn. The
extracted omega line shape was found to be sensitive to the background
subtraction. In experiments at the tagged photon facility of the Mainz MAMI
accelerator photoproduction of mesons from light nuclear targets (deuteron and
3He) has been studied. The experiments used the combined Crystal Ball/TAPS
setup in Mainz. Measurements of eta- and pi0-photoproduction off a liquid
3He-target have been used for the search for the formation of eta-mesic 3He.
The installation of the WASA detector at COSY opened a unique possibility to
search for the 4He-eta bound state with high statistics and high acceptance. We
are conducting a search via an exclusive measurement of the excitation function
for the dd -> 3He p pi- reaction.Comment: Proceedings of New Frontiers In QCD 2010: Exotic Hadron Systems And
Dense Matter 18 Jan - 19 Mar 2010, Kyoto, Japa
Hadrons in Nuclei: Experiments and Perspectives
The question of the origin of hadron masses is one major issue in the
understanding of the strong interaction. The challenge is addressed by
searching for indications of in-medium modifications of hadron properties and
studying hadrons in nuclei. The quest driving in-medium studies is to
understand the origin of hadron masses in the context of spontaneous chiral
symmetry breaking.
The experimental status of the modification of hadron properties in the
nuclear medium is discussed including experiments using hadron, heavy-ion, and
photon beams. Particular emphasis is put on the production of light mesons from
nuclei.
A number of experimental programs is underway to provide a detailed
comparison of properties of free hadrons and hadrons embedded in nuclei. The
existing experimental efforts are discussed and possibilities are introduced
for the new WASA-at-COSY facility, initially focussed on investigations of
symmetries and symmetry breaking, to contribute to the field.Comment: To appear in the proceedings of 23rd International Nuclear Physics
Conference (INPC 2007), Tokyo, Japan, 3-8 Jun 200
Experiments on Hadrons in Nuclei: ω and η mesons
Data on the photoproduction of ω mesons on nuclei have been re-analyzed in search for in-medium modifications. The data were taken with the Crystal Barrel(CB)/TAPS detector system at the ELSA accelerator facility in Bonn. The extracted ω line shape was found to be sensitive to the background subtraction.In experiments at the tagged photon facility of the Mainz MAMI accelerator photoproduction of mesons from light nuclear targets (deuteron and 3He) has been studied. The experiments used the combined Crystal Ball/TAPS setup in Mainz. Measurements of η- and π0-photoproduction off a liquid 3He-target have been used for the search for the formation of η-mesic 3He. The installation of the WASA detector at COSY opened a unique possibility to search for the 4He – η bound state with high statistics and high acceptance
Electromagnetic Transition Form Factors of Light Mesons
Electromagnetic transition form factors provide basic knowledge of the structure of hadrons and address the validity of vector meson dominance. Transition form factors are of renewed interest due to the impact on the interpretation of the g-2 measurements