Separation of S- wave pseudoscalar and pseudovector amplitudes in pi^- p---> pi^+ pi^- n reaction on polarized target

Abstract

A new analysis of S-wave production amplitudes for the reaction ${\pi }^{-}{p}_{\uparrow }\to {\pi }^{+}{\pi }^{-}n$ on a transversely polarized target is performed. It is based on the results obtained by the CERN-Cracow -Munich collaboration in the pion-pion energy range from 600 MeV to 1600 MeV at 17.2 GeV/c ${\pi }^{-}$ momentum. Energy-independent separation of the S-wave pseudoscalar amplitude ($\pi$ exchange) from the pseudovector amplitude ($a_1$ exchange) is carried out using assumptions much weaker than those in all previous analyses. We show that, especially around 1000 MeV and around 1500 MeV, the $a_1$ exchange amplitude cannot be neglected. The scalar-isoscalar $\pi \pi$ phase shifts are calculated using fairly weak assumptions. Below the $K\overline{K}$ threshold we find two solutions for the $\pi -\pi$ phase shifts, for which the phases increase slower with the effective $\pi -\pi$ mass than the P-wave phases. Both solutions are consistent with a broad $f_0(500)$ but only one is similar to the well-known "down" solution. We find also the third solution (with a somewhat puzzling behavior of inelasticity) which exhibits a narrow $f_0(750)$ claimed by Svec. All the solutions undergo a rapid change at the $K\overline{K}$ threshold. Above 1420 MeV the phase shifts increase with energy faster than those obtained without the polarized-target data. This phase behavior as well as an increase of the modulus of the $a_1$-exchange amplitude can be due to the presence of the $f_0(1500)$.

25 Latex pages + 15 Postscript figures

References in corpus (6)

• Resurrection of the Sigma Meson
• Numerical Evidence for the Observation of a Scalar Glueball
• An Analysis of ππ-Scattering Phase Shift and Existence of σ(555) particle
• Resonance $f_0(1500)$: Is it a scalar glueball ?
• Mass and width of sigma(750) scalar meson from measurements of piN->pi(-)pi(+)N on polarized targets
• Issues in Light Hadron Spectroscopy

Cited by in corpus (79)

• Glueballs, Hybrids, Multiquarks. Experimental facts versus QCD inspired concepts
• N/D Description of Two Meson Amplitudes and Chiral Symmetry
• The pion-pion scattering amplitude. IV: Improved analysis with once subtracted Roy-like equations up to 1100 MeV
• From controversy to precision on the sigma meson: a review on the status of the non-ordinary $f_0(500)$ resonance
• Roy equation analysis of pi pi scattering
• The Status of Glueballs
• A new analysis of $\pi K$ scattering from Roy and Steiner type equations
• Precise determination of the f0(600) and f0(980) pole parameters from a dispersive data analysis
• Bethe-Salpeter Approach for Unitarized Chiral Perturbation Theory
• Proton-Antiproton Annihilation and Meson Spectroscopy with the Crystal Barrel
• Regge analysis of the pi pi scattering amplitude
• Isoscalar $\pi \pi ,K\overline{K},\eta \eta$ scattering and the $\sigma ,f_0,f_2$ mesons from QCD
• The pion-pion scattering amplitude
• Resonances from meson-meson scattering in U(3) CHPT
• The pion-pion scattering amplitude. III: Improving the analysis with forward dispersion relations and Roy equations
• KK bar scattering amplitude to one loop in chiral perturbation theory, its unitarization and pion form factors
• Bethe-Salpeter Approach for Meson-Meson Scattering in Chiral Perturbation Theory
• Couplings of light I=0 scalar mesons to simple operators in the complex plane
• Chiral dynamics in form factors, spectral-function sum rules, meson-meson scattering and semilocal duality
• On the size of the sigma meson and its nature
• Improved dispersion relations for γγ\to π^0π^0
• Three channel model of meson-meson scattering and scalar meson spectroscopy
• Chiral study of the $a_0(980)$ resonance and $\pi \eta$ scattering phase shifts in light of a recent lattice simulation
• Elimination of ambiguities in pion-pion phase shifts using crossing symmetry
• The Inverse Amplitude Method in $\pi \pi$ Scattering in Chiral Perturbation Theory to Two Loops
• Dynamical generation of pseudoscalar resonances
• Distinguishing two kinds of scalar mesons from heavy meson decays
• Two photons into π^0π^0
• Dynamical light vector mesons in low-energy scattering of Goldstone bosons
• Scalar radius of the pion and zeros in the form factor
• Global parameterization of $\pi \pi$ scattering up to 2 GeV
• The pion-pion scattering amplitude. II: Improved analysis above $\bar{K}K$ threshold
• Gluonium nature of the sigma/f_0(600) from its coupling to KK
• Dispersive $\pi K\to \pi K$ and $\pi \pi \to K\bar{K}$ amplitudes from scattering data, threshold parameters and the lightest strange resonance $\kappa$ or $K_0^{\ast }(700)$
• The sigma and f_0(980) from Ke4 + pi-pi scatterings data
• A partial wave analysis of the ${\pi }^0{\pi }^0$ system produced in ${\pi }^{-}p$ charge exchange collisions
• New study of the isotensor pi-pi interaction
• Chiral extrapolation of pion-pion scattering phase shifts within standard and unitarized Chiral Perturbation Theory
• New explanation of the GAMS results on the $f_0(980)$ production in the reaction ${\pi }^{-}p\to {\pi }^0{\pi }^{0}n$
• Scalar Glueball Mixing and Decay
• Final-state interactions in the CP asymmetries of charm-meson two-body decays
• Finite volume treatment of pi pi scattering and limits to phase shifts extraction from lattice QCD
• Collision times in pi-pi and pi-K scattering and spectroscopy of meson resonances
• Serber symmetry, Large Nc and Yukawa-like One Boson Exchange Potentials
• The scalar radius of the pion
• Data-driven dispersive analysis of the $\pi \pi$ and $\pi K$ scattering
• The origin of light $0^{+}$ scalar resonances
• Self-consistent statistical error analysis of $\pi \pi$ scattering
• On the uncertainty estimates of the $\sigma$-pole determination by Padé approximants
• Coupled Channel Analysis of S-Wave Pion-Pion and Kaon-Kaon Photoproduction
• $\pi \pi$ scattering S wave from the data on the reaction ${\pi }^{-}p\to {\pi }^0{\pi }^{0}n$
• Axion-pion thermalization rate in unitarized NLO chiral perturbation theory
• Dispersive analysis of the $S$-, $P$-, $D$-, and $F$-wave $\pi \pi$ amplitudes
• Coupled channel study of a0 resonances
• Thermal behaviors of light scalar resonances at low temperatures
• Scalar mesons: in search of the lightest glueball
• Two-Meson Form Factors in Unitarized Chiral Perturbation Theory
• Global parametrizations of $\pi \pi$ scattering with dispersive constraints: Beyond the S0 wave
• A New Decomposition of pion-pion S-wave Interaction
• Thermal contribution of unstable states
• K Kbar photoproduction and S-P wave interference
• Dalitz plot studies of $D^0\to K_S^0{K}^{+}{K}^{-}$ decays in a factorization approach
• Masses and widths of scalar-isoscalar multi-channel resonances from data analysis
• Non-Perturbative Study of the Light Pseudoscalar Masses in Chiral Dynamics
• Can parameters of f_0-mesons be determined correctly analyzing only pion-pion scattering?
• Matching the Electroweak Penquins Q_7 and Q_8
• pi pi scattering, pion form factors and chiral perturbation theory
• Mechanisms of the $f_0(980)$ production in the reaction ${\pi }^{-}p\to {\pi }^0{\pi }^{0}n$
• Central hadron production in crossing of dedicated hadronic beams
• Coupled channel effects in pion pion S-wave interaction
• On concise hypotheses for the interpretation of a wide scalar resonance as gauge boson binary in QCD - some new analyses
• Bounds on the Light Quark Masses: the scalar channel revisited
• Scalar isovector resonance photoproduction through the final state meson-meson interactions
• Cross sections for 2-to-3 meson-meson scattering
• Dispersive determination of resonances from $\pi \pi$ scattering data
• Revealing dipion correlations for the observed substructure near the ${\pi }^{+}{\pi }^{-}$ mass threshold in $\psi (3686)\to J/\psi {\pi }^{+}{\pi }^{-}$
• Forward dispersion relations and Roy equations in pi-pi scattering
• Strong interaction between kaons in the reactions e+ e- --> K+ K- gamma and e+ e- --> K0 K0bar gamma
• Precision dispersive approaches versus unitarized Chiral Perturbation Theory for the lightest scalar resonances $\sigma /f_0(500)$ and $\kappa /K_0^{\ast }(700)$