Speaker
Mr
Johannes Bernhard
(Institut f. Kernphysik, JGU Mainz)
Description
The COMPASS experiment at CERN SPS completed its data taking with hadron beams ($p$, $\pi$, $K$) in the years 2008 and 2009 by collecting a large set of data on different targets ($H_2$, $Pb$, $Ni$, $W$). These data are dedicated to hadron spectroscopy, where the focus is directed to the search for exotic mesons and gluonic excitations. The production of such states is known to be favoured in glue-rich environments, $e.g.$ so-called OZI-forbidden processes. The OZI rule postulates that processes with disconnected quark line diagrams are forbidden. On the one hand, the study of the degree of OZI violation in vector meson production yields the possibilty to learn more about the involved production mechanisms while on the other hand it helps to understand the nucleon's structure itself. Contrary to former experiments, the large data sample allows for detailed studies in respect to both the four-momentum transfer $t$ and Feynman's variable $x_F$, respectively. We present results from the ongoing analysis on the comparison of the production of the vector mesons $\omega$ and $\phi$ in $p~p~\longrightarrow~p~(\omega/\phi)~p$, where the possibilty of measuring the spin alignment of both vector mesons at the same time makes COMPASS unique.
Primary author
Mr
Johannes Bernhard
(Institut f. Kernphysik, JGU Mainz)
Co-author
Mrs
Stina Karin Schoenning
(CERN)