Related papers: Extraction of P11 resonances from pi N data
We present a new model independent amplitude analysis of reaction pi(-)p->pi(-) pi(+)n measured at CERN at 17.2 GeV/c on polarized target using a Monte Carlo method for dipion mass 580-1080 MeV. The two solutions for measured moduli…
The pion-nucleon amplitude is considered in the vicinity of the elastic scattering threshold within a relativistic dynamical model dressing the pi N N and pi N Delta vertices self-consistently with an infinite number of meson loops. The…
We present a nucleon resonance analysis by simultaneously considering all pion- and photon-induced experimental data on the final states gamma N, pi N, 2 pi N, eta N, K Lambda, K Sigma, and omega N for energies from the nucleon mass up to…
A classification of the $IJ^{PC}=00^{++}$ mesons is performed on the basis of the K-matrix analysis of meson spectra in the reactions: (i) GAMS data on $\pi p\to \pi^0\pi^0 n$, $\eta\eta n$, $\eta\eta' n$; (ii) Crystal Barrel data on $p\bar…
Recently we presented a successful strategy to extract the position of the two $\Lambda(1405)$ poles from experimental photoproduction data on the $\gamma p \to K^+ \pi^0 \Sigma^0 $ reaction at Jefferson Lab. Following a similar strategy,…
The unitary isobar model MAID2007 has been used to analyze the recent data of pion electroproduction. The model contains all four-star resonances in the region below W=2 GeV and both single-Q^2 and Q^2 dependent transition form factors…
The recoil proton polarization has been measured in the p (\vec e,e'\vec p) pi^0 reaction in parallel kinematics around W = 1232 MeV, Q^2 = 0.121 (GeV/c)^2 and epsilon = 0.718 using the polarized c.w. electron beam of the Mainz Microtron.…
The determination of non-spherical angular momentum amplitudes in nucleons at long ranges (low Q^{2}), was accomplished through the $p(\vec{e},e'p)\pi^0$ reaction in the Delta region at $Q^2=0.060$, 0.127, and 0.200 (GeV/c)^2 at the Mainz…
We develop the phenomenological amplitude of the $\pi N \to \pi \pi N$ reaction describing the exchanges of $\Delta$ and $N_{*}$ along with the OPE mechanism. The contribution of the latter contains 4 independent low energy parameters (up…
JLab has recently found indications of the possible existence of a $\Sigma NN$ resonance at $(3.14 \pm 0.84) - i (2.28 \pm 1.2)$ MeV. In the past, using models that exploit symmetries between the two-baryon sector with and without…
We report the observation of two narrow structures at 10610MeV/c^2 and 10650MeV/c^2 in the pi^{\pm}Upsilon(nS) (n=1,2,3) and pi^{\pm}h_b(mP) (m=1,2) mass spectra that are produced in association with a single charged pion in Upsilon(5S)…
Nucleon and $\Delta$ resonances in the fourth resonance region are studied in a multichannel partial-wave analysis which includes nearly all available data on pion- and photo-induced reactions off protons. In the high-mass range, above…
In a previous paper (Commun. Theor. Phys. 57 (2012) 841), we proposed a method to distinguish poles of different dynamical origin, in a unitarized amplitude of $\pi\pi\, K\bar K$ system. That is based on the observation that `A Breit-Wigner…
A separable potential model of three coupled channels (pion-pion, kaon-antikaon and an effective four pion) has been constructed and applied in the analysis of the isoscalar S-wave pion-pion and kaon-antikaon phase shifts and inelasticities…
With an effective Lagrangian approach, we give a full analysis on the $NN \to NN\pi\pi$ and $\bar{N}N\to \bar{N}N\pi\pi$ reactions by exploring the roles of various resonances with mass up to 1.72 GeV. We find large contributions from…
The scalar -- isoscalar pi-pi phase shifts are analysed using a separable potential model of three coupled channels (pipi, KK and an effective 2pi2pi system). Model parameters are fitted to two sets of solutions obtained in a recent…
By simultaneously analyzing the cross section data of $e^+e^-\rightarrow D\bar D, D\bar D^*, D^*\bar D^*, D\bar D\pi$ in a coupled-channel scheme with unitarity, we found that, in contrast to the conventional wisdom, the pole of…
An experiment on the radiative pi^+ meson photoproduction from the proton (gamma p->gamma pi^+ n) was carried out at the Mainz Microtron MAMI in the kinematic region 537 MeV <E_{gamma}<817 MeV, 140^o<theta_{gamma-gamma'}^cm<180^o. The pi^+…
Measurements of the analysing power for the p(pol)p --> ppeta reaction have been performed in the close-to-threshold energy region at beam momenta of p_{beam}=2.010 and 2.085 GeV/c, corresponding to excess energies of Q=10 and 36 MeV,…
A partial wave analysis of pion photoproduction has been obtained in the framework of fixed-t dispersion relations valid from threshold up to 500 MeV. In the resonance region we have precisely determined the electromagnetic properties of…