New parameterization of the resonant production amplitudes near an inelastic threshold

New formulae for the resonant scattering and the production amplitudes near an inelastic threshold are derived. It is shown that the Flatte formula, frequently used in experimental analyses, is not sufficiently accurate. Its application to data analysis can lead to a substantial distortion of the effective mass spectra and of the resonance pole positions. A unitary parameterization, satisfying a generalized Watson theorem for the production amplitudes, is proposed. It can be easily applied to study production processes, multichannel meson-meson interactions and the resonance properties, including among others the scalar resonances a0(980) and f_0(980).Comment: 4 pages, 1 figure, contribution to MESON 2008, Tenth International Workshop on Meson Production, Properties and Interaction, 6-10 June, Krakow, Poland, to be published in International Journal of Modern Physics

Multichannel Interaction Analysis of Scalar Mesons Below 1800 MeV

Properties of scalar--isoscalar mesons in a mass range from pi-pi threshold up to 1800 MeV are analysed using an unitary model with separable interactions in three decay channels: pi-pi, K-anti K and an effective 2pi-2pi. Different solutions are obtained by fitting pi-pi and K-anti K data. Analytical structure of the meson-meson multichannel amplitudes is studied with a special emphasis on the important role played by the S-matrix zeroes. The dependence of the positions of S-matrix singularities on the interchannel coupling strength is investigated. Poles, located in the complex energy plane not too far from the physical region, are interpreted as scalar resonances: a wide f0(500), a narrow f0(980) and a relatively narrow f0(1400). In all our solutions two resonances, lying on different sheets, in the energy region between 1300 MeV and 1500 MeV are found. These states may be compared with the resonances f0(1370) and f0(1500) seen in the experiments at CERN. Total, elastic and inelastic channel cross sections, branching ratios and coupling constants are evaluated and compared with available data.Comment: Talk given at Workshop on Hadron Spectroscopy, Frascati (Rome) - Italy, March 8-12, 1999. To be published in Frascati Physics Series, 8 pages, 4 figures, included file frascatiphys.st

Anaysis of high energy K+K- photoproduction on hydrogen

We have analyzed the K+K- photoproduction on hydrogen in the effective mass region around the mass of the phi(1020) meson. The interference of the S-wave contribution with the P-wave has been studied. Both scalar resonances f0(980) and a0(980) have been taken into account. We have obtained a good description of the available experimental data, in particular the mass distributions and the moments of the kaon angular distribution. Our calculations give values of the integrated S-wave total photoproduction cross section between 4 and 7 nb for the K+K- effective mass range around the phi(1020) mass and at the laboratory photon energy near 5 GeV. These numbers favor lower experimental estimates obtained at DESY.Comment: 3 pages, 3 eps figures, needs ws-ijmpa.cls style, talk given by Lukasz Bibrzycki at 8th International Workshop on Meson Production, Properties and Interaction, MESON 2004, Krakow, Poland, 4-8 June 2004, to appear in Int. Journal of Modern Physics

Final state interactions in B+- to K+ K- K+- decays

Charged B decays to three charged kaons are analysed in the framework of the QCD factorization approach. The strong final state K+K-interactions are described using the kaon scalar and vector form factors. The scalar non-strange and strange form factors at low K+K- effective masses are constrained by chiral perturbation theory and satisfy the two-body unitarity conditions. The latter stem from the properties of the meson-meson amplitudes which describe all possible S-wave transitions between three coupled channels consisting of two kaons, two pions and four pions. The vector form factors are fitted to the data on the electromagnetic kaon interactions. The model results are compared with the Belle and BaBar data. Away from phi(1020) resonance, in the S-wave dominated K+K- mass spectra, a possibility for a large CP asymmetry is identified.Comment: 7 pages, 4 figures, modified version published in Physics Letters

Amplitudes Fitted to Experimental Data and to Roy's Equations

The scalar-isoscalar, scalar-isotensor and vector-isovector pi-pi amplitudes are fitted simultaneously to experimental data and to Roy's equations. The resulting amplitudes are compared with those fitted only to experimental data. No additional constraints for the pi-pi threshold behaviour of the amplitudes are imposed. Threshold parameters are calculated for the amplitudes in the three waves. Spectrum of scalar mesons below 1.8 GeV is found from the analysis of the analytical structure of the fitted amplitudes.Comment: 3 pages, 1 figure. Talk given at MESON 2004: 8th International Workshop on Meson Production, Properties and Interactions, Cracow, Poland, 4-8 Jun 2004. Submitted to Int.J.Mod.Phys.

Three channel model of meson-meson scattering and scalar meson spectroscopy

New solutions on the scalar -- isoscalar $\pi\pi$ phase shifts are analysed together with previous $K\bar{K}$ results using a separable potential model of three coupled channels ($\pi\pi$, $K\bar{K}$ and an effective $2\pi 2\pi$ system). Model parameters are fitted to two sets of solutions obtained in a recent analysis of the CERN-Cracow-Munich measurements of the $\pi^- p_{\uparrow} \to \pi^+ \pi^- n$ reaction on a polarized target. A relatively narrow (90 -- 180 MeV) scalar resonance $f_0(1400-1460)$ is found, in contrast to a much broader ($\Gamma \approx 500$ MeV) state emerging from the analysis of previous unpolarized target data.Comment: 10 Latex pages + 6 postscript figure

Properties of scalar--isoscalar mesons from multichannel interaction analysis below 1800 MeV

Scalar-isoscalar mesons are studied using an unitary model in three channels: pi-pi, K-anti K and an effective 2pi-2pi. All the solutions, fitted to the pi-pi and K-anti K data, exhibit a wide f0(500), a narrow f0(980) and two relatively narrow resonances, lying on different sheets between 1300 MeV and 1500 MeV. These latter states are similar to the f0(1370) and f0(1500) seen in experiments at CERN. Branching ratios are compared with available data. We have started investigations of some crossing symmetry and chiral constraints imposed near the pi-pi threshold on the scalar-isoscalar, scalar-isotensor and P-wave pi-pi amplitudes.Comment: Talk given at XVth Particles and Nuclei Int. Conf. (PANIC99), Uppsala, Sweden, June 10-16, 1999; 4 pages, 3 figures, file espcrc1.sty include

K Kbar photoproduction and S-P wave interference

Results of a new analysis of the $K^+K^-$ photoproduction at two photon energies $E_\gamma = 4{GeV}$ and $5.65{GeV}$ with a particular emphasis on the $S$-wave production are presented. We show that the proper treatment of all the helicity components of the $S$- and $P$-waves enables one to eliminate the reported discrepancies in extraction of the $S$-wave photoproduction cross section from experimental data.Comment: 25 pages, 5 figures, new predictions at 8 GeV added in Fig.

Strong and Weak Interactions in B to pi+ pi- K Decays

To describe the weak three-body B decays into pi+ pi- K, we recently derived amplitudes based on two-body QCD factorization followed by pi+ pi- final state interactions in isoscalar S- and isovector P-waves. We study here the sensitivity of the results to the values of the B to f0(980) transition form factor and to the effective decay constant of the f0(980).Comment: Contribution to the Few Body 18 conference in Santos, Brazil, August 21-26, 2006, 5 pages, to be published in Nuclear Physics

Interference between f0(980) and rho(770) resonances in B --> pion-pion-kaon decays

We study the contribution of the strong interaction between the two pions in S- and P-waves to the weak B --> pion pion kaon decay amplitudes. The interference between these two waves is analyzed in the pion-pion effective mass range of the rho(770) and f0(980) resonances. We use a unitary pion-pion and antikaon-kaon coupled-channel model to describe the S-wave interactions and a Breit-Wigner function for the P-wave amplitude. The weak B-decay amplitudes, obtained from QCD factorization, are supplemented with charming penguin contributions in both waves. The four complex parameters of these long distance terms are determined by fitting the model to the BaBar and Belle data on B^{+,-,0} --> pi+ pi- K^{+,-,0} branching fractions, CP asymmetries, pion-pion effective mass and helicity-angle distributions. This set of data, and in particular the large direct CP-asymmetry for B^{+,-} --> rho0(770) K^{+,-} decays, is well reproduced. The interplay of charming penguin amplitudes and the interference of S- and P-waves describes rather successfully the experimental S and A values of the CP-violating asymmetry for both B0 --> f0(980) K0S and B0 --> rho0(770) K0S decays.Comment: 12 pages, 7 figures, subsection VD, Appendix A and one reference adde