https://doi.org/10.1051/epjconf/20147303002
Precision spectroscopy with COMPASS and the observation of a new iso-vector resonance
1 Physik Department E18, Technische Universität München, James Franck Str., 85748 Garching, Germany
2 Excellencecluster “Universe”, Boltzmannstr. 2, 85748 Garching, Germany
a e-mail: stephan.paul@tum.de
Published online: 9 June 2014
We report on the results of a novel partial-wave analysis based on 50 ⋅ 106 events from the reaction π− + p → π−π−π+ + precoil at 190 GeV/c incoming beam momentum using the COMPASS spectrometer. A separated analysis in bins of m3π and four-momentum transfer t′ reveals the interference of resonant and non-resonant particle production and allows their spectral separation. Besides well known resonances we observe a new iso-vector meson a1(1420) at a mass of 1420 MeV/c2 in the f0(980)π final state only, the origin of which is unclear. We have also examined the structure of the 0++ππ-isobar in the JPC = 0−+, 1++, 2−+ three pion waves. This clearly reveals the various 0++ππ-isobar components and its correlation to the decay of light mesons.
© Owned by the authors, published by EDP Sciences, 2014
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
