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The past year 2006 has been a very successful one for the institute: first off, a major milestone has been achieved with the in-time installation of the WASA detector at an internal target station of COSY and its subsequent commissioning. WASA-at-COSY is ready to take data and the collaboration is looking forward to its first data production run, approved by the COSY-PAC and scheduled for spring 2007. Furthermore, after very productive scientific programs, the internal experiment COSY-11 and the external beam experiments at BIG KARL have finished their data taking phases, and are now completing the analysis of the existing data. The following highlights top the list of the important scientific results: • Pentaquark studies: the TOF-collaboration has very carefully analysed their dedicated high-statistics data sample, and did not find a signal for the $\circleddash^{+}$(1540). This finding has been supported by the ANKE-collaboration in a different final state. • Bound $\eta$-nucleus states: data with unprecedented precision for the $^{3}He\eta$ system have been obtained both at ANKE and at COSY-11 in the d p-reaction, exploiting the unique possibilities at the internal COSY beam during the ramp-up of the energy. The very rapid rise of the total cross section close to threshold implies a very large $^{3}He\eta$ scattering length and hence the presence of a quasi-bound state extremely close to threshold. • Hyperon-nucleon interactions: chiral effective field theory has successfully been applied to the interactions between nucleons and hyperons. This paves the way to a model-independent approach of strange quark effects in nuclei. • Accelerator studies: the COSY accelerator has been used for spin manipulations of a polarized deuteron beam, and clear indications for a deuteron spin resonance have been obtained. All results mentioned have recently been submitted for publication. More details and further results can be found in the main text. In addition to WASA, the two other major installations continue to be developed further: [...]

The year 2005 has been a challenging one for the institute: as a consequence of the “mixed results” of the first review in February 2004 within the Research Programme “Physics of Hadrons and Nuclei” in the Research Field “Structure of Matter” of the Helmholtz Centres, IKP was faced with substantial cuts in resources for 2005. An even more serious threat ensued with possible further reductions for the years 2006 – 2009, depending, however, on the outcome of an “in-depth” evaluation of the IKP activities. The review on “COSY and FZJ contributions to FAIR”, conducted by an international committee, and headed by Peter Paul (BNL, USA), took place on two days in April 2005. IKP presented its strategy for the further use of COSY and, in close collaboration with GSI (Darmstadt), the cooperation towards the construction of the FAIR facility. In its report, issued later last year, the committee almost fully supported our plans, and as a result and the financial agreements, which have been negotiated in the meantime, we now have a solid basis for the remainder of the first funding period (2006 – 2009). — I would like to take this opportunity to thank all who contributed to this great success in one way or the other. One of the explicit recommendations of the committee was to give green light for the relocation of the WASA detector from CELSIUS (Uppsala, Sweden) to COSY. The detector dismount at TSL and transfer to FZJ was completed in 2005, and we are now in the process of installing WASA at an internal target station of COSY — more details are given in the main text. Commissioning of WASA is scheduled to begin in the second half of 2006 and first experiments are expected to start in 2007. In connection with the WASA-at-COSY project, the IKP had decided to reduce the amount of COSY beamtime for users in 2005 by about 2000 hours. The increased downtime is needed to install WASA in the COSY ring, but also has the positive side-effect that the cost-savings will be used to finance necessary maintenance and upgrades of WASA detector components and electronics. This was part of the financing concept which has been worked out between the IKP directorate and the FZJ board of management. On the scientific frontier, IKP has made a number of important contributions (details can again be found in the main text): • The ANKE collaboration has found indications for a heavy hyperon state Y$^{0*}$(1480) in the analysis of pp $\rightarrow$ pK$^{+} \pi$X at a beam momentum of 3.65 GeV/c. • The GEM collaboration has determined the mass of the h meson with unprecedented accuracy, exploiting the reaction pd $\rightarrow$ $^{3}He \eta$ and simultaneously pd $\rightarrow$ t$\pi^{+}$ at the BIG KARL magnetic spectrometer (see cover picture and corresponding article). • At COSY the efficiency for flipping the proton spin by means of a small rf dipole has been pushed to more than 99.9%. • The intensity of the polarized ion source for H$^{−}$ was raised to 50$\mu$A, thus doubling its original specification. The involvement of the IKP in the FAIR project to be realized at the GSI was fully honored by the committee. Our efforts are focused on the design and construction of the High Energy Storage Ring (HESR) and significant contributions to the PANDA detector. We are dedicated to make this endeavor a success being aware of its great potential to advance hadron physics and connected fields during the next decades. We have been able to meet the challenges of 2005 not only due to our own efforts, but because we could rely on the support and advice of many people. I like to express our gratitude to all of them, the colleagues from the infrastructure of our Research Center (FZJ) in particular ZAM, ZAT, and ZEL, the people from the universities and research centers from Germany and all over the world and, last but not least, the CANU community.

The year 2004 had been marked by events and activities that will be of strategic relevance for our institute. In February our institute was reviewed together with the GSI within the framework of the “Program Oriented Funding”, which represents a new paradigm for science funding of the Helmholtz centres. This evaluation took place at the GSI, scrutinizing the Research Program “Physics of Hadrons and Nuclei”, which is part of the Research Field “Structure of Matter”. As the major recommendations of this council, an “on-site” and “in-depth” review of the future activities of the institute, especially with respect to our close collaboration with GSI within the FAIR-project was proposed as well as to present a full proposal for the transfer of WASA from Uppsala to COSY to a dedicated review committee. The HGF-Senate has decided to postpone/defer any decision on budgets for the years 2006 to 2009 until the findings of the on-site review, which will take place in April 2005, are available. The WASA proposal has been critically examined in October 2004 by an extended program advisory committee. It concluded unanimously that this detector in connection with COSY would constitute an outstanding physics opportunity and that the proposed physics program has unquestionably strategic relevance. The institute has significantly intensified its engagement in the FAIR-project, which will set the stage for the mid- and long-term perspective in hadron physics. In collaboration with other partners our institute has taken on a leading role in the consortium that is planning, designing (and later building) the “High Energy Storage Ring” (HESR) of FAIR. In 2004 the IKP has played a prominent role in the timely completion of the Technical Reports for HESR, PANDA, PAX and FLAIR. As outlined in our PoF-application, the institute has the following strategy for its future position within the scientific portfolio of the Helmholtz organisation (HGF): • Scientific exploitation of COSY and its experimental facilities: – Hadron physics with hadronic probes – Preparatory investigations for the FAIR project of GSI (Darmstadt) • Involvement in FAIR: – Planning, designing and building of HESR, the “High Energy Storage Ring” for anti-protons – Contributions to antiproton experiments and corresponding detector systems (PANDA, PAX, FLAIR) It is evident that the timescale for the transition from COSY to HESR needs to be intertwined with the actual realization of the FAIR-project. As a result of an intense discussion within CANU (COSY Association of Networking Universities), it was agreed that COSY will be an indispensable experimental facility for the intervening period in order to sustain a viable hadron physics community. An efficient migration of the CANU-user community to the HESR is only conceivable if experimental activities can continue nearly seamlessly. As mentioned above, we intend to transfer WASA (currently installed at CELSIUS of TSL, Uppsala, Sweden) to COSY — a corresponding Memorandum-of-Understanding between Uppsala University and FZJ was signed in December. As significant resources will be allocated to the HESR, PANDA, and other activities related to the FAIR-project, WASA — together with ANKE and TOF — will be the only detector systems operated at COSY in the near future. We already phased out nuclear spectroscopy and JESSICA during the past year. As in the years before we had meetings of our international advisory committees, the IKP-Beirat and PAC for the COSY experimental program. I would like to take the opportunity to thank all of its members for their valuable advice and constructive discussions. We also have had retirements of colleagues in 2004; I would like to mention: Prof. Detlev Filges and Prof. Kurt Kilian, long-term director of IKP I. I want to express our deep thanks to all retirees for their work and contributions as well as our best wishes for their future. We are very pleased to have successors for two retired directors (J. Speth, K. Kilian): • Prof. Ulf-G. Meißner, holding a chair at the “Helmholtz Institut für Strahlen- und Kernphysik” at the “Rheinische Friedrich-Wilhelms Universität Bonn”, who had acted as provisional director of the IKP-theory since 2003, took over as director in October. • Prof. James Ritman from the “Justus-Liebig Universität Gießen”, holding now a chair at the “Ruhr-Universität Bochum”, is the new head of IKP I since September. A hearty welcome and all the best to the new leadership and to all other new staff members of IKP. In closing, I would like to thank all colleagues, collaborators, friends from within the institute, the Research Center (FZJ) — in particular ZAM, ZAT and ZEL — and national and international universities and institutions for their support and dedication that was key to make COSY a world class facility and the IKP a center for hadron physics with hadronic probes.