In the analysis a status and parameters of the scalar, vector, and tensor mesonic resonances are obtained and compared with other results. Possible classification of the resonance states in terms of the SU(3) multiplets is discussed.

The experimental data on the processes ππ → ππ, KK, ηη, ηη ′ in the I G J P C = 0 + 0 ++ channel have been jointly analyzed to study the status and nature of the f0. The method of analysis is based on analyticity and unitarity and uses an uniformization procedure. Some spectroscopic implications from results of the analysis are discussed.

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Exploiting the isobar model, kaon photo-and electroproduction on the proton in the resonance region comes under scrutiny. An upgrade of our previous model, comprising higher-spin nucleon and hyperon exchanges in the consistent formalism, was accomplished by implementing energydependent widths of nucleon resonances, which leads to a different choice of hadron form factor with much softer values of cutoff parameter for the resonant part. For a reliable description of electroproduction, the necessity of including longitudinal couplings of nucleon resonances to virtual photons was revealed. We present a new model whose free parameters were adjusted to photo-and electroproduction data and which provides a reliable overall description of experimental data in all kinematic regions. The majority of nucleon resonances chosen in this analysis coincide with those selected in our previous analysis and also in the Bayesian analysis with the Regge-plus-resonance model as the states contributing to this process with the highest probability.

The recent CLAS 2005, SAPHIR 2003, LEPS, and the old, pre-1972, data on K + Λ photoproduction are compared with theoretical calculations in the energy region of E lab γ < 2.6 GeV in order to learn about their mutual consistency. The isobaric models Kaon-Maid and Saclay-Lyon, along with new fits to the CLAS data are utilized in this analysis. The SAPHIR 2003 data are shown to be coherently shifted down with respect to the CLAS, LEPS, and pre-1972 data, especially at forward kaon angles. The CLAS, LEPS, and pre-1972 data in the forward hemisphere can be described satisfactorily by using the isobaric model without hadronic form factors. The inclusion of the hadronic form factors yields a strong suppression of the cross sections at small kaon angles and c.m. energies larger than 1.9 GeV, which is not observed in the existing experimental data. We demonstrate that the discrepancy between the CLAS and SAPHIR data has a significant impact on the predicted values of the mass and width of the "missing-resonance" D13(1895) in the Kaon-Maid model.Kaon photoproduction on the nucleon provides an important tool for understanding the dynamics of hyperonnucleon systems. Accurate information on the elementary amplitude is vital for calculating the cross sections of the hypernuclear photoproduction, since the amplitude serves as the basic input, which determines the accuracy of predictions [1,2]. At present, these calculations can be compared with high resolution spectroscopy data of the hypernuclei, which are available from the experiments performed at the Jefferson Laboratory [3]. Since the hypernucleus production cross section is sensitive to the elementary amplitude, especially at forward kaon angles, a precise description of the elementary process at this kinematics is obviously desired.The two sets of ample, good quality, experimental data provided recently by the CLAS (CL05) [4] and SAPHIR (SP03) [5] collaborations were expected to help us learn more about the process; however, they reveal a lack of consistency at forward and backward kaon angles [4] (see also Ref. [6] in which results of the first analysis of the CLAS data [7] were used). The previous SAPHIR data by Tran et al. (SP98) [8] also display different behavior at small kaon angles compared to that observed in the old pre-1972 data, e.g., from Bleckmann et al. [9] (hereafter referred to as OLD). The uncertainty in the experimental information causes a wide range of model predictions at forward kaon angles. The situation is illustrated in Fig. 1, where the CL05, SP03, SP98 and OLD data (as listed in Ref. [13]) are compared with predictions of different phenomenological models. Obviously, the data and the models, which were fitted to various data sets, differ significantly for θ K < 45 • , which leads to a large input uncertainty in the hypernuclear calculations [2].At present, there are two large data sets, the latest CLAS and SAPHIR ones, with comparable statistical significance, but they diverge in some kinematic regions. Measurements of the differential cross ...