Contribution to a conference proceedings/Internal Report

PUBDB-2015-05678

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png The OZI Rule and Spin Alignment of Vector Mesons at COMPASS

Schönning, K. ; COMPASS Collaboration (Collaboration Author)

2014
Deutsches Elektronen-Synchrotron, DESY Hamburg

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Please use a persistent id in citations: doi:10.3204/DESY-PROC-2014-04/36

Report No.: DESY-PROC-2014-04

Abstract: The reaction $p p \rightarrow p V p$ ($V$ = $\omega$, $\phi$) 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 $\approx$4. Its kinematic dependence of the Feynman $x_F$ and the $M_{pV}$ mass is discussed in terms of diffractive production of baryon resonances in competition with central production. The $M_{p\omega}$ spectrum has a rich structure, indicating the importance of baryon resonances decaying into $p\omega$, in sharp contrast to the structureless $M_{p\phi}$ spectrum. Outside the resonant region, the OZI violation factor is about 8, independently of $x_F$.The spin density matrix element $\rho_{00}$ of the vector mesons is studied in selected reference frames. Dependences of the vector meson spin alignment on $x_F$ and $M_{pV}$ are found.

Keyword(s): spin: alignment ; p: beam ; baryon resonance: production ; spin: density matrix ; Iizuka-Okubo-Zweig rule: violation ; cross section: ratio: measured ; hydrogen: liquid: target ; diffraction: production ; vector meson ; COMPASS ; spectrometer ; kinematics ; structure ; Feynman

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Contributing Institute(s):

1. LHC/ATLAS Experiment (ATLAS)
2. LHC/CMS Experiment (CMS)
3. Uni Hamburg / Experimentalphysik (UNI/EXP)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF3-611) (POF3-611)

Experiment(s):

1. No specific instrument

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Database coverage:

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Linked articles:

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Book/Proceedings/Internal Report Schmidt, A. (Editor)>Extern* ; Sander, C. (Editor)DESY*
Proceedings, 20th International Conference on Particles and Nuclei (PANIC 14)
2014Panic2014, Panic2014, HamburgHamburg, Germany, 25 Aug 2014 - 29 Aug 20142014-08-252014-08-29 Hamburg : Deutsches Elektronen-Synchrotron, DESY 1-754 (2014) [10.3204/DESY-PROC-2014-04]2014     Files  Fulltext BibTeX | EndNote: XML, Text | RIS

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