Speaker
Mr
Tobias Schlüter
(LMU Munich)
Description
From COMPASS 2008 data a sample of 40,000 events of the type $\pi^-p\to\eta'(\to\eta(\gamma\gamma)\pi^+\pi^-)\pi^-p_{\textrm{slow}}$ with $-t>0.1\,\textrm{GeV}^2/c^2$ was selected for a partial-wave analysis. Monte Carlo simulations display a smooth dependence of the acceptance on kinematic variables. Study of the alternative final state with $\eta\to\pi^+\pi^-\pi0(\gamma\gamma)$ provides a check of the procedure.
The goal of this analysis is to compare the relative strengths of the $\eta'\pi$ $P_+$-, $D_+$- and $G_+$-waves to those observed at VES and BNL at lower bombarding energies. In those analyses, unnatural parity transfer is strongly suppressed. We study the evolution to COMPASS energies of the known broad $P_+$-wave intensity and its phase motion relative to the $D_+$-wave near the $a_2(1320)$ mass and with respect to a broad $D_+$-wave structure at higher mass. The $t$-dependence is studied in detail. The results are compared to those obtained for other 2-pseudoscalar channels.
Primary author
Mr
Tobias Schlüter
(LMU Munich)
Co-author
Prof.
Wolfgang Dünnweber
(LMU Munich)
