Speaker
Mr
Sebastian Uhl
(Technische Universität München)
Description
COMPASS is a fixed-target experiment at the CERN SPS aimed to study the structure and dynamics of hadrons. Data with negative (mostly $\pi^-$) hadron beams of $190\,\text{GeV}/c$ has been taken to study in particular light mesons. Their spectrum is investigated in diffractive dissociation reactions with final-states containing $\pi$ and $\eta$. At four-momentum transfers to the target between $0.1$ and $1.0\,\text{GeV}^2/c^2$ the properties of known resonances are studied, and new, possibly exotic, states are searched. Novel analysis techniques have been developed to also probe the sub-systems of the final-states.
The structure of light mesons is studied in photo-production reactions induced by a pion beam scattering off solid targets. The radiative widths of the $a_2\left(1320\right)$ and, for the first time, that of the $\pi_2\left(1670\right)$ have been extracted from COMPASS data. In addition these reactions can be used to measure the polarizability of the $\pi$, and compare this to predictions of chiral perturbation theory.
Primary author
Mr
Sebastian Uhl
(Technische Universität München)
