The new Facility for Antiproton and Ion Research (FAIR) is currently being built at GSI in Darmstadt (Germany), where the PANDA experiment represents the central part of the hadron physics programme. The field of hadron spectroscopy has gained new momentum by the discovery of various new hadronic resonances especially in the charmonium sector over the past two decades. The nature of many of the so-called charmonium-like exotic XYZ states are, however, not yet understood. Precise measurements of hadron properties are mandatory to sort out different theoretical models and clarify the nature of these new states. A well known example is the X(3872) (now χc1(3872)) --- although being the first of the new charmonium-like states discovered since 2003, the nature of this state is still not understood. The most important ingredients to address this issue are measurements of the mass, natural width and in particular the shape of the χc1(3872). While a high statistic analysis (the most precise one up to now) recently published by LHCb demonstrated very limited power to identify the nature, it will be shown, that high-precision energy scan experiments carried out with pbar-p annihilation at PANDA will have a high impact on resolving the current ambiguities.

Talk given at the GlueX Meeting at Jefferson Lab, Newport News, USA als introduction for a meeting with US groups interested in PANDA