Related papers: Complete Experiments for Pion Photoproduction
I present some recent results on neutral pion photo- and electroproduction in the threshold region and discuss the low energy theorem for $E_{0+}$ and some novel ones for the $P$-waves. I also study the two-pion production process $\gamma N…
Within the Excited Baryon Analysis Center we have performed a dynamical coupled-channels analysis of the available $p(e,e' \pi)N$ data in the region of $W \leq $ 1.6 GeV and $Q^2 \leq$ 1.45 (GeV/c)$^2$. The channels included are $\gamma^*…
I review the interesting tale of the electric dipole amplitude in neutral pion photoproduction and the resulting consequences. I also discuss why there is new life related to P--wave multipoles. Electroproduction is briefly touched upon.
A number of recent multipole analyses from Mainz, RPI, BNL and Virginia Tech (VPI) have focused on the first resonance region. One goal common to these studies was an improved set of Delta(1232) photo-decay amplitudes. There has been…
Data on the polarization observables T, P, and H for the reaction $\gamma p\to p\pi^0$ are reported. Compared to earlier data from other experiments, our data are more precise and extend the covered range in energy and angle substantially.…
We present the first model independent determination of S- and P-wave helicity amplitudes from CERN measurements of pi(-)p -> pi(-)pi(+)n on polarized target at small t and dipion masses 580-1080 MeV. The purely analytical determination of…
We compare the methods of amplitude reconstruction, for a complete experiment and a truncated partial wave analysis, applied to the photoproduction of pseudo-scalar mesons. The approach is pedagogical, showing in detail how the amplitude…
Meson spectroscopy is going through a revival with the advent of high statistics experiments and new advances in the theoretical predictions. The Constituent Quark Model (CQM) is finally being expanded considering more basic principles of…
The multipole content of pion photoproduction at the $\Delta^+ (1232)$ resonance has been extracted from a data set dominated by recent Mainz Microtron (MAMI) precision measurements. The analysis has been carried out in the Athens Model…
We study the reaction of pion photoproduction on the nucleon in the framework of chiral perturbation theory with explicit $\Delta(1232)$ degrees of freedom. In the covariant approach, we give results up to order $\epsilon^3$ in the small…
This dissertation treats the problem of complete experiments for pseudoscalar meson photoproduction, in the context of a truncated partial-wave analysis (TPWA). The work contains algebraic and numerical considerations. The influence of…
Photoproduction of $\pi^0\pi^{\pm}$-pairs from quasifree nucleons bound in the deuteron has been investigated to study the helicity dependence of this reaction. Measurements with a liquid deuterium target were used to extract the…
We measured angular distributions of recoil-polarization response functions for neutral pion electroproduction for W=1.23 GeV at Q^2=1.0 (GeV/c)^2, obtaining 14 separated response functions plus 2 Rosenbluth combinations; of these, 12 have…
Measurement of the semi-inclusive pi+ electroproduction off the proton, performed with CLAS detector at Jefferson Lab, has been presented. The obtained fully-differential cross sections, including the azimuthal angle between hadronic and…
The fragmentation of deuterons into pions with nonzero angle emitted in the kinematical region forbidden for free nucleon-nucleon collisions is analyzed. The inclusive relativistic invariant spectrum of pions and the tensor analyzing power…
The dependence of the nucleon polarization in the reaction $e^+ + e^- \to N + \bar{N} +\pi^0 $ over different invariant variables in frame of the non-resonant mechanism, has been derived. The nucleon polarization is expressed in terms of…
The new experimental data of kaon photoproduction on the nucleon, gamma p -> K+ Lambda, have been analyzed by means of a multipoles model. Different from the previous models, in this analysis the resonance decay widths are constrained to…
New data on pion-photoproduction off the proton have been included in the partial wave analyses Bonn-Gatchina and SAID and in the dynamical coupled-channel approach J\"ulich-Bonn. All reproduce the recent new data well: the double…
We propose to extend the investigations of the eta meson production in nucleon-nucleon collisions by studying single and double polarization observables. Over the last years, the eta meson has been studied at several different experiments…
Kaon photo- and electroproduction in all six isospin channels are investigated by means of an isobaric model. It is found that existing models can only partially describe the current experimental data. Moreover, the extracted coupling…