Speakers
Dr
Frank Nerling
(University of Freiburg)
Johannes Bernhard
(Institut f. Kernphysik, JGU Mainz)
Description
The COMPASS experiment at CERN SPS is dedicated to the study of hadron
structure and spectroscopy. One goal of the physics programme using hadron beams is the search for new states, in particular the search for $J^{PC}$ spin-exotic states and glueballs. COMPASS has started to contribute to the puzzle of the existence of spin-exotic mesons by the published 2004 pilot run data, showing a significant production strength for an exotic $J^{PC}=1^{-+}$ state at 1.66\,GeV/${\rm c^2}$~[1], the newly taken 2008/09 data will further clarify the situation. Apart of the spin-exotic $\pi_1(1600)$ resonance observed
in various decay channels and experiments, also a spin-exotic $\pi_1(2000)$ was reported in the past in the $f_1(1285)\pi$ decay channel by the E852 experiment at BNL [2], however, this state still lacks any confirmation. We present a first event selection of the diffractively produced $(K\bar{K}\pi\pi)^{-}$ system showing clean $f_1(1285)$ and $f_1(1420)$ resonances at competing statistics with BNL, and extending the spectrum beyond 2\,GeV/${\rm c^{2}}$. A partial-wave analysis started on $f_1(1285)\pi$ and $f_1(1420)\pi$ decay channels will further complete the search for spin-exotics in the 2008/09 COMPASS data, the $f_1(1420)\pi$ system was never studied before.
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$\lbrack 1 \rbrack$ M.~Alekseev {\it et al.}, COMPASS collaboration, {\it Phys. Rev. Lett}, {\bf 104} (2010) {241803}.\\
$\lbrack 2 \rbrack$ J.~Kuhn {\it et al.}, {\it Phys. Lett. B} {\bf 595} (2004) {109}.
Primary authors
Dr
Frank Nerling
(University of Freiburg)
Johannes Bernhard
(Institut f. Kernphysik, JGU Mainz)