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The project A.2 of the SFB/TR16 "Subnuclear Structure of Matter" aimed at a combined multichannel partial wave analysis of all or of most data on pion and photo-induced reactions for invariant masses from the Δ(1232) region to 2300MeV. In this review the most important results are presented. It is shown that the data and their partial wave analysis have improved our understanding of the dynamics of excited light-quark baryons significantly. [ABSTRACT FROM AUTHOR]

We summarise recent results on the spectrum of ground-state and excited baryons and their form factors in the framework of functional methods. As an improvement upon similar approaches we explicitly take into account the underlying momentum-dependent dynamics of the quark-gluon interaction that leads to dynamical chiral symmetry breaking. For light octet and decuplet baryons we find a spectrum in very good agreement with experiment, including the level ordering between the positive- and negative-parity nucleon states. Comparing the three-body framework with the quark-diquark approximation, we do not find significant differences in the spectrum for those states that have been calculated in both frameworks. This situation is different in the electromagnetic form factor of the Δ, which may serve to distinguish both pictures by comparison with experiment and lattice QCD. [ABSTRACT FROM AUTHOR]

Within project A.1 of the SFB/TR16 "Subnuclear Structure of Matter", a large amount of data on photoproduction reactions has been accumulated at the Bonn Electron Stretcher Accelerator ELSA with the CBELSA/TAPS detector and was analysed in detail. In particular, data have been taken with unpolarized or with linearly or circularly polarized photons and with unpolarized or with longitudinally or transversely polarized protons. Photoproduction off neutrons was studied to determine the helicity amplitudes for the excitation of resonances off neutrons. In a partial wave analysis of the data, new resonances have been found and the properties of new and of known resonances have been determined, including the measurement of partial widths of so far unmeasured decay modes. [ABSTRACT FROM AUTHOR]

Recent progress in baryon spectroscopy is reviewed. In a common effort, various groups have analyzed a set of new high-precision polarization observables from ELSA. The Jülich-Bonn group has finalized the analysis of pion-induced meson-baryon production, the photoproduction of pions and eta mesons, and (almost) the K⋀ final state. As data become preciser, statistical aspects in the analysis of excited baryons become increasingly relevant and several advances in this direction are proposed. [ABSTRACT FROM AUTHOR]

In this contribution I discuss recent results in light quark baryon spectroscopy involving CLAS data and higher level analysis results from the partial wave analysis by the Bonn-Gatchina group. New baryon states were discovered largely based on the open strangeness production channels γp → K+⋀ and γp → K+Σ0. The data illustrate the great potential of the kaon-hyperon channel in the discovery of higher mass baryon resonances in s-channel production. Other channels with discovery potential, such as γp → pω and γp → ϕp are also discussed. In the second part I will demonstrate on data the sensitivity of meson electroproduction to expose the active degrees of freedom underlying resonance transitions as a function of the probed distance scale. For several of the prominent excited states in the lower mass range the short distance behavior is described by a core of three dressed-quarks with running quark mass, and meson-baryon contributions make up significant parts of the excitation strength at large distances. Finally, I give an outlook of baryon resonance physics at the 12 GeV CEBAF electron accelerator. [ABSTRACT FROM AUTHOR]

In this contribution, we present the unquenched quark model as an extension of the constituent quark model that includes the effects of sea quarks via a 3P0 quark-antiquark pair-creation mechanism. Particular attention is paid to the spin and flavor content of the proton, magnetic moments and β decays of octet baryons. [ABSTRACT FROM AUTHOR]

The AMADEUS experiment deals with the investigation of the low-energy kaon-nuclei hadronic interaction at the DAΦNE collider at LNF-INFN. The aim is to answer fundamental longstanding questions in the non-perturbative QCD strangeness sector. The antikaon-nucleon potential is investigated searching for signals from possible bound kaonic clusters, which would open the possibility for the formation of cold dense baryonic matter. The confirmation of this scenario may imply a fundamental role of strangeness in astrophysics. AMADEUS step 0 consisted in the reanalysis of 2004/2005 KLOE dataset, exploiting K- absorptions in H, 4He, 9Be and 12C in the setup materials. In this paper, together with a review on the multi-nucleon K- absorption and the particle identification procedure, the first results on the Σ0p channel will be presented including a statistical analysis on the possible accomodation of a deeply bound state. [ABSTRACT FROM AUTHOR]

We present the results of the measurement of Collins asymmetries in electron-positron annihilation events with the BABAR detector in the process e+e- → h1h2X, for charged hadrons where h1h2 = KK, Kπ, or ππ. Using 468 fb-1 of data collected by BABAR at the SLAC PEP-II B factory, we observe distinct azimuthal asymmetries for hadrons in opposite thrust hemispheres of events, with the asymmetries increasing in proportion to the hadron energies. We find Kπ asymmetries similar to those for ππ pairs, with the high-energy KK asymmetries generally larger. [ABSTRACT FROM AUTHOR]

We present the observation of the azimuthal asymmetries of two charged pions in the process e+e- → ππX at BESIII. These asymmetries can be attributed to the Collins Fragmentation Function (CFF), and their dependence on the pion momentum, transverse momentum of hadrons, and polar angle is studied. [ABSTRACT FROM AUTHOR]

Transition Distribution Amplitudes (TDA) are parametrizations of the hadronic matrix elements that occur in the perturbative Quantum Chromo Dynamics (QCD) calculations of a certain family of reactions within the framework of collinear factorization.We propose a complete feasibility study of the measurement of one of the reactions covered by the TDA models p̄p → π0J/Ψ (J/Ψ → e+e-) at PANDA (AntiProton ANnihilation at DArmstadt) experiment currently under construction at the future FAIR (Facility for Antiproton and Ion Research). We show that PANDA will be ideally suited to access the relevant observables, in particular the pion-to-nucleon TDAs (πN TDAs) which are important for the understanding of the pion cloud contribution in the nucleon wave function. [ABSTRACT FROM AUTHOR]

The pion properties in symmetric nuclear matter are investigated with the Quark-Meson Coupling (QMC) Model plus the light-front constituent quark model (LFCQM). The LFCQM has been quite successful in describing the properties of pseudoscalar mesons in vacuum, such as the electromagnetic elastic form factors, electromagnetic radii, and decay constants. We study the pion properties in symmetric nuclear matter with the in-medium input recalculated through the QMC model, which provides the in-medium modification of the LFCQM. [ABSTRACT FROM AUTHOR]

A new approach to asymptotically free interactions is developed in terms of the Fock-space Hamiltonians obtained by applying the renormalization group procedure for effective particles to quantum field theory. We present the approach on the example of pure SU(3) Yang-Mills theory. [ABSTRACT FROM AUTHOR]

Recent results of the HADES collaboration are presented with emphasis on the e+e- production in elementary reactions. Via the Dalitz decay of baryonic resonances (R →Ne+e-), access is given to the time-like electromagnetic structure of baryonic transitions. This process could be measured for the first time for Δ(1232) in pp reactions at 1.25 GeV. At higher energies, the sensitivity of e+e- emission to transition form factors of the Vector Dominance type has been demonstrated. Very recently, experiments with the GSI pion beam started, allowing for more direct studies of baryonic resonances Dalitz decays. In addition, the measurement of hadronic channels provides a new data base for baryon spectroscopy issues, in particular in the 2πN channel. [ABSTRACT FROM AUTHOR]

This contribution reports on the latest status of the feasibility studies for the measurement of time-like proton electromagnetic form factors (FF's) at the PANDA experiment [1] at FAIR (Germany). Electromagnetic FF's are fundamental quantities parameterizing the electric and magnetic structure of hadrons. In the time-like region proton FF's can be accessed experimentally through the annihilation processes p¯p → l+l- (l = e, μ), assuming that the interaction takes place through the exchange of one virtual photon. Due to the low luminosity available at colliders in the past, an individual determination of the time-like electric and magnetic proton FF's was not feasible. The statistical precision, at which the proton FF's will be determined at PANDA, is estimated for both signal processes p¯p → l+l- (l = e, μ) using the PandaRoot software, which encompasses full detector simulation and event reconstruction. The signal identification and suppression of the main background process (p¯p → π+π-) is studied. Different methods have been used to generate and analyze the processes of interest. The results from the different analyses show that time-like electromagnetic FF's can be measured at PANDA with unprecedented statistical accuracy. [ABSTRACT FROM AUTHOR]

Using e+e- annihilation data taken with the CLEO-c detector at √s = 3770 MeV and 4170 MeV, we report the first measurements of the electromagnetic form factors of the Λ0, Σ0, Σ+, Ξ0, Ξ-, and Ω- hyperons for the large timelike momentum transfers of Q2 = 14.2 GeV2 and 17.4 GeV2, respectively. The enhancement in 0 production over that of 0, both of which have the same uds quark content, gives evidence for significant diquark correlations in these hyperons. Improved easurements of the branching fractions of ψ(2S) to hyperon--antihyperon pairs are also reported. [ABSTRACT FROM AUTHOR]

The Initial State Radiation method in the BABAR experiment has been used to measure the time-like electromagnetic form factors at the momentum transfer from 9 to 42 (GeV/c)2 for proton and from 7 to 56 (GeV/c)2 for charged kaon. The obtained data show the tendency to approach the QCD asymptotic prediction for kaons and space-like form factor values for proton. The BABAR data have been used together with data from other experiments, to perform a model-independent determination of the relative phases between the single-photon and the three-gluon amplitudes in Ψ → KK̄ decays. The values of the branching fractions measured in the reaction e+e- → K+K- are shifted due to interference of resonant and nonresonant amplitudes. We have determined the absolute values of the shifts to be 5% for J/Ψ and 15% for Ψ(2S) decays. [ABSTRACT FROM AUTHOR]

The Λ(1405) baryon is difficult to detect in experiment, absent in many quark model calculations, and supposedly manifested through a two-pole structure. Its uncommon properties made it subject to numerous experimental and theoretical studies in recent years. Finite-volume Lattice-QCD eigenvalues for different quark masses were recently reported by the Adelaide group. We compare these eigenvalues to predictions of a model based on Unitary Chiral Perturbation Theory (UCHPT). The UCHPT calculation predicts the quark mass dependence remarkably well. It also explains the overlap pattern with different meson-baryon components, mainly πΣ and K¯ N, at different quark masses. More accurate Lattice QCD data are required to draw definite conclusions on the nature of the Λ(1405). [ABSTRACT FROM AUTHOR]

Studying excited nucleon structure through exclusive electroproduction reactions is an important avenue for exploring the nature of the non-perturbative strong interaction. Electrocouplings for N* states in the mass range below 1.8 GeV have been determined from analyses of CLAS πN, ηN, and ππN data. This work made it clear that consistency of independent analyses of exclusive channels with different couplings and non-resonant backgrounds but the same N* electro-excitation amplitudes, is essential to have confidence in the extracted results. In terms of hadronic coupling, many high-lying N* states preferentially decay through the ππN channel instead of πN. Data from the KY channels will therefore be critical to provide an independent analysis with which to compare the extracted electrocouplings for the high-lying N* states against those determined from the πN and ππN channels. A program to study excited N* decays to non-strange and strange exclusive final states using CLAS12 will measure differential cross sections to be used as input to extract the γvNN* transition form factors for the most prominent N* states in the range of invariant energy W up 3 GeV in the virtually unexplored domain of momentum transfers Q2 up to 12 GeV2. [ABSTRACT FROM AUTHOR]

Recent experiments using the Crystal Ball/TAPS setup at the MAMI accelerator in Mainz, Germany, continue to study the properties and the excitation spectrum of the nucleon with meson photoproduction. Electromagnetic excitations of the proton and neutron are essential for understanding their isospin decomposition. The electromagnetic coupling of photons to protons is different than that to neutrons in certain states. Hence, a complete partial wave analysis (PWA) can assist in yielding more information about any reaction, but requires the determination of polarization observables. Polarization observables play a crucial role as they are essential in disentangling the contributing resonant and non-resonant amplitudes, whereas cross section data alone is not sufficient for separating broad overlapping resonances. Preliminary results of polarization observables of η, single, and double π production o a polarized neutron (dButanol) target will be shown with comparison to predictions of recent multipole analyses. These results will greatly increase the world database on pseudoscalar meson production on neutrons. [ABSTRACT FROM AUTHOR]

One of the remaining challenges within the standard model is to gain a good understanding of QCD in the nonperturbative regime. One key step toward this aim is baryon spectroscopy, investigating the spectrum and the properties of baryon resonances. To get access to resonances with small πN partial width, photoproduction experiments provide essential information. In order to extract the contributing resonances, partial wave analyses need to be performed. Here, a complete experiment is required to unambiguously determine the contributing amplitudes. This involves the measurement of carefully chosen single and double polarization observables. The CBELSA/TAPS experiment with a longitudinally or transversely polarized target and an energy tagged, linearly or circularly polarized photon beam allows the measurement of a large set of polarization observables. Due to its good energy resolution, high detection efficiency for photons, and the nearly complete solid angle coverage, it is ideally suited for the measurement of photoproduction of neutral mesons decaying into photons. Recent results for various double polarization observables in π0 and η photoproduction and their impact on the partial wave analysis are discussed. [ABSTRACT FROM AUTHOR]

We review theoretical progress and prospects for determining the nucleon's static dipole polarisabilities from Compton scattering on few-nucleon targets, including new values; see Refs. [1-5] for details and a more thorough bibliography. [ABSTRACT FROM AUTHOR]

Baryon spectroscopy is an indispensable tool for investigating the nature of strong interaction within baryons. The study of vector-meson photoproduction is expected to improve our understanding of the properties of known baryon resonances and also immensely aid in discovering new higher-mass resonances. Polarization observables, in addition to unpolarized cross sections, are required to identify the contributing resonances to these reactions with minimal ambiguities. Preliminary results from the FROST experiment on beam-polarization observables in γ →p → p→ as well as γ →p ! pω+ωπ using a linearly-polarized beam and a transversely-polarized FROzen Spin butanol Target will be presented. The latter reaction will provide important information on N* to (broad) ρ vector-meson decay modes, which is diffcult to extract directly from the data. [ABSTRACT FROM AUTHOR]

In recent years, the BESIII experiment has accumulated large samples of J/ψ, ψ' and ψ(3770) decays. Through radiative and hadronic charmonium decays, the baryon spectrum can be explored in a way that complements studies of other existing data sets. In this report, recent results in baryon spectroscopy at BESIII will be presented. [ABSTRACT FROM AUTHOR]

In this talk we present an approach to the Λb → J/ψK- p reaction, where we look at the invariant mass of K- p and also πΣ, with a view to determine the shape and production rate of the Λ(1405) resonance. We compare the results obtained with the analysis of the same reaction, made a posteriori by the LHCb collaboration, in which two pentaquark states were claimed. At the same time we show the results of another work, prompted by the findings of the LHCb collaboration, where we show that there is consistency with the results obtained in the study of the Λb → J/ψK- p reaction with other results previously reported about a hidden charm baryon state. [ABSTRACT FROM AUTHOR]

I review recent results on charmed baryon decay, mass and width measurements using the world's largest data set of reconstructed e+e- annihilation events collected in the Upsilon energy range. [ABSTRACT FROM AUTHOR]

In this talk we review the results about the interaction of B¯N, B¯Δ, B¯*N and B¯*Δ states with beauty B = 1, together with their coupled channels, using the extended local hidden gauge approach. The Λb(5912) and Λb(5920) observed in the experiment are dynamically generated from the meson-baryon interaction, and they couple mostly to B¯*N, which are degenerate with the Weinberg-Tomozawa interaction. In addition, three more states with I = 0 and eight more states with I = 1 are predicted. [ABSTRACT FROM AUTHOR]

In this report, femtoscopic measurements with pp, ..., ..., p,,, p..., ...Λ and p..., Λ... pairs in Pb-Pb collisions at √sNN= 2.76 TeV registered by ALICE at the LHC are presented. Emission source sizes extracted from the correlation analysis with (anti)protons grow with the event multiplicity, as expected. A method to extract the interaction potentials (e.g. for p,,, and ...Λ pairs) based on femtoscopy analysis is discussed. The importance of taking into account the so-called residual correlations induced by pairs contaminated by secondary particles is emphasized for all analyses mentioned above. [ABSTRACT FROM AUTHOR]