Abstract
The COMPASS collaboration at CERN dedicated the 2008 and 2009 run time to hadron spectroscopy measurements with emphasis on the mesonic sector. At 190 GeV/c beam momentum, diffractive and double-Reggeon/Pomeron production mechanisms contribute. Studying vector meson production allows to explore this relatively unknown transition domain. We present results on the ratio of production yields for p p →(1020) p p ϕ and p p → p p ω(782) and its xF dependence where we find an OZI rule violation in the order of a factor of 3. In addition, the spin alignment of ω and ϕ as a function of xF is investigated.
Highlights
The interplay of production mechanisms such as diffractive, central or Coulomb production at medium beam energies in the order of 100 GeV has been poorly investigated
We present results on the ratio of production yields for p p → p p φ(1020) and p p → p p ω(782) and its xF dependence where we find an OZI rule violation in the order of a factor of 3
One approach to single out the different mechanisms is a study of the production of well-known vector mesons, e.g. φ(1020) and ω(782), exploring the Okubo-Zweig-Iizuka (OZI) rule [1] which states that only processes with connected quark lines are allowed
Summary
The interplay of production mechanisms such as diffractive, central or Coulomb production at medium beam energies in the order of 100 GeV has been poorly investigated. Due to the deviation from ideal mixing of the φ and ω mesons, the production cross section ratio R(φ/ω) is determined within the OZI model to be 4.2 · 10−3 in any reaction with non-strange hadrons [2] This has been found to be well-fulfilled in a multitude of reactions [3] at several beam energies [4], but apparent violations were observed in proton - anti-proton annihilations at rest and in nucleon-nucleon collisions. Since the ω and φ mesons are measured simultaneously with the same set-up and the same triggers, systematic uncertainties cancel to large extend
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
