Test of OZI violation in vector meson production with COMPASS

TL;DR

This paper reports on COMPASS experiment data analyzing OZI rule violations in vector meson production, providing insights into production mechanisms and nucleon structure through detailed measurements of nd \u03a6 mesons.

Contribution

It presents new experimental results on OZI violation in vector meson production using a large data set and simultaneous spin alignment measurements, advancing understanding of hadron production.

Findings

Evidence of OZI rule violation in vector meson production.

Comparison of nd a6 production mechanisms.

Insights into nucleon structure from meson production data.

Abstract

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 using different targets (H2, Pb, Ni, W). These data are dedicated to hadron spectroscopy, where the focus is directed to the search for exotic bound states of quarks and gluons (hybrids, glueballs). 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 possibility to learn more about the involved production mechanisms. 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 Feynman's variable xF. We present results from the ongoing analysis on the comparison of \omega and \phi vector mesons production in pp->p(\omega/\phi)p, where the possibility of measuring the spin alignment of both vector mesons at the same time makes COMPASS unique.