Study of resonant structure of Swave amplitudes in pi()p>pi()pi(+)n measured on polarized target at 17.2 GeV/c in the mass range of 5801080 MeV
Abstract
We have performed a new model independent amplitude analysis of reaction $\pi^ p \to \pi^ \pi^+ n$ measured at CERN at 17.2 GeV/c on polarized target. The analysis extends the range of dipion mass from 600880 MeV used in the previous study to 5801080 MeV. Our purpose is to study the role of $f_0(980)$ interference and to better determine the resonance parameters of $\sigma(750)$ resonance from fits to both Swave amplitudes $\bar S^2\Sigma$ and $S^2\Sigma$ with recoil nucleon transversities ``up'' and ``down'', respectively. This work is the first attempt to determine resonance parameters of a resonance from BreitWigner fits to production amplitudes of opposite transversity. We used several fitting procedures to understand the resonant structure of the Swave amplitudes in this mass range. The simultaneous fit to $\bar S^2\Sigma$ and $S^2\Sigma$ with two common $\sigma$ poles yields an excellent fit with a lower $\chi^2/dpt$ than the separate fits. All amplitudes are dominated by a $\sigma$ state with $m_\sigma = 786 \pm 24$ MeV and $\Gamma_\sigma = 130\pm 47$ MeV. All amplitudes receive a weaker contribution from a narrower $\sigma'$ state with $m_{\sigma'} = 670 \pm 30$ MeV and $\Gamma_{\sigma'} = 59 \pm 58$ MeV. We propose to identify $\sigma'(670)$ and $\sigma(786)$ with colourelectric and colourmagnetic modes of lowest mass scalar gluonium $0^{++} (gg)$.
 Publication:

arXiv eprints
 Pub Date:
 July 1997
 DOI:
 10.48550/arXiv.hepph/9707495
 arXiv:
 arXiv:hepph/9707495
 Bibcode:
 1997hep.ph....7495S
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 47 pages, 13 Figures