Speaker
Mr
Florian Haas
(Physik-Department E18 Technische Universität München)
Description
Diffractive dissociation reactions studied at the COMPASS experiment, CERN, provide access to the light meson spectrum. During a pilot run in 2004, using a pion beam and a lead target, 500k events of pi- pi- pi+ final state events with masses below 2.5 GeV/c^2 were recorded, yielding a significant signal for the p1(1600) spin-exotic resonance. After a significant upgrade of the spectrometer in 2007, the following two years were dedicated to meson spectroscopy. Using again a pion beam, but now with a liquid hydrogen target, an unique statistics of ~100M events of the same final state was gathered in 2008. During a short campaign in 2009, the liquid target was exchanged by several solid state targets in order to compare final states produced on targets with different atomic numbers.
After a short summary of a partial wave analysis (PWA) of 2004 data, the focus will be on a PWA of 2008 data in the same kinematic range of momentum transfer (0.1 GeV^2/c^2 < t’ < 1.0 GeV^2/c^2).
In addition the progress of the analysis of data recorded with solid state targets in 2009 and a comparison with 2008 and 2004 data will be presented.
Primary author
Mr
Florian Haas
(Physik-Department E18 Technische Universität München)