Johann Marton

Marton has as the following main areas of scientific interest: (1) Low-energy strong interaction with strangeness. The field of low-energy strong interaction involving strangeness is full of surprises and recent experiments using x-ray spectroscopy of kaonic atoms succeeded in solving long-standing puzzles. Marton is member of the SIDDHARTA Collaboration and Collaborations at J-PARC (E15, E17) and he is spokesperson of the networking activity LEANNIS (Low Energy Antikaon Nucleon and Nuclei Interaction Studies) in the EU project (FP7) HadronPhysics3 which is devoted to this research field and brings together experimentalists and theoreticians.
Recently the abnormal strong interaction shift of the 2p state of kaonic helium-4 was disproved in experiments of our group at KEK/Japan and finally with SIDDHARTA at LNF/Italy.
The precision x-ray spectroscopy made remarkable progress in the our experiment at DAFNE. New data of the strong interaction observables of kaonic hydrogen (i.e. the strong interaction induced energy shift and width of the 1s ground state) were measured with a precision surpassing all previous experimental results. These results have strong impact on the theory since they are providing the constraints at threshold.
The results on kaonic atoms are also important for the question of the existence of kaonic nuclear systems where indications on the existence of K-pp were found. The nature of Lambda(1405) is a key issue in the understanding of antikaon-nucleon interaction but is still unclear and is subject of models with the assumption of a one or two pole structure. SIDDHARTA2 at DAFNE will attack the open problems. Furthermore, experiments on this subject are under way at J-PARC/Japan.
(2) Strong interaction studies with antiproton annihilation (PANDA at FAIR). In the charm quark region many charmonium states were discovered – however, precision data are still to be measured. The precise resonance scanning method of PANDA with antiprotons stored in a storage ring can study these charmonium states directly by proton-antiproton annihilation. Moreover, new hadronic objects of up-to-now unexplained nature – called X, Y, Z – were discovered by experiments at B factories (Babar, Belle). The PANDA (antiProton-ANnihilation at DArmstadt) experiment at the future FAIR research center (Facility for Antiproton and Ion Research) can largely contribute in clarifying these new states. The PANDA physics program covers a broad range of scientific topics in hadron physics covering precision meson spectroscopy in the charmonium range, studies of in-medium modification and the search for new exotic objects. Marton has been a member of the PANDA Collaboration for more than 10 years and involved in many tasks like R&D for Cherenkov detectors, timing detectors and the internal target system.