TY - CONF AU - Schönning, Karin TI - The OZI Rule and Spin Alignment of Vector Mesons at COMPASS IS - DESY-PROC-2014-04 CY - Hamburg PB - Deutsches Elektronen-Synchrotron, DESY M1 - PUBDB-2015-05678 M1 - DESY-PROC-2014-04 SP - 165-168 PY - 2014 AB - The reaction p p → p V p (V = ω, ϕ) has been studied with the COMPASS spectrometer in 2008 and 2009, using a 190 GeV/c proton beam impinging on a liquid hydrogen target.The measured cross section ratio ratio violates the OZI prediction by a factor of ≈ 4. Its kinematic dependence of the Feynman x<sub>F</sub> and the M<sub>pV</sub> mass is discussed in terms of diffractive production of baryon resonances in competition with central production. The M<sub>pω</sub> spectrum has a rich structure, indicating the importance of baryon resonances decaying into pω, in sharp contrast to the structureless M<sub>pϕ</sub> spectrum. Outside the resonant region, the OZI violation factor is about 8, independently of x<sub>F</sub>.The spin density matrix element ρ<sub>00</sub> of the vector mesons is studied in selected reference frames. Dependences of the vector meson spin alignment on x<sub>F</sub> and M<sub>pV</sub> are found. T2 - Panic2014 CY - 25 Aug 2014 - 29 Aug 2014, Hamburg (Germany) Y2 - 25 Aug 2014 - 29 Aug 2014 M2 - Hamburg, Germany KW - spin: alignment (autogen) KW - p: beam (autogen) KW - baryon resonance: production (autogen) KW - spin: density matrix (autogen) KW - Iizuka-Okubo-Zweig rule: violation (autogen) KW - cross section: ratio: measured (autogen) KW - hydrogen: liquid: target (autogen) KW - diffraction: production (autogen) KW - vector meson (autogen) KW - COMPASS (autogen) KW - spectrometer (autogen) KW - kinematics (autogen) KW - structure (autogen) KW - Feynman (autogen) LB - PUB:(DE-HGF)8 ; PUB:(DE-HGF)15 DO - DOI:10.3204/DESY-PROC-2014-04/36 UR - https://bib-pubdb1.desy.de/record/291944 ER -