Dokumentenart: | Artikel | ||||
---|---|---|---|---|---|
Titel eines Journals oder einer Zeitschrift: | The European Physical Journal C | ||||
Verlag: | SPRINGER | ||||
Ort der Veröffentlichung: | NEW YORK | ||||
Band: | 62 | ||||
Nummer des Zeitschriftenheftes oder des Kapitels: | 4 | ||||
Seitenbereich: | S. 659-695 | ||||
Datum: | 2009 | ||||
Institutionen: | Physik > Institut für Theoretische Physik > Lehrstuhl Professor Schäfer > Arbeitsgruppe Andreas Schäfer | ||||
Identifikationsnummer: |
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Stichwörter / Keywords: | VECTOR-MESON PRODUCTION; INELASTIC-SCATTERING; CROSS-SECTION; P(0) MESONS; HERA; QCD; LEPTOPRODUCTION; DISTRIBUTIONS; POLARIMETER; HYDROGEN; | ||||
Dewey-Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik > 530 Physik | ||||
Status: | Veröffentlicht | ||||
Begutachtet: | Ja, diese Version wurde begutachtet | ||||
An der Universität Regensburg entstanden: | Ja | ||||
Dokumenten-ID: | 67005 |
Zusammenfassung
Spin Density Matrix Elements (SDMEs) describing the angular distribution of exclusive rho (0) electroproduction and decay are determined in the HERMES experiment with 27.6 GeV beam energy and unpolarized hydrogen and deuterium targets. Eight (fifteen) SDMEs that are related (unrelated) to the longitudinal polarization of the beam are extracted in the kinematic region 1 < Q (2)< 7 GeV2, 3.0 < W < ...
Zusammenfassung
Spin Density Matrix Elements (SDMEs) describing the angular distribution of exclusive rho (0) electroproduction and decay are determined in the HERMES experiment with 27.6 GeV beam energy and unpolarized hydrogen and deuterium targets. Eight (fifteen) SDMEs that are related (unrelated) to the longitudinal polarization of the beam are extracted in the kinematic region 1 < Q (2)< 7 GeV2, 3.0 < W < 6.3 GeV, and -t < 0.4 GeV2. Within the given experimental uncertainties, a hierarchy of relative sizes of helicity amplitudes is observed. Kinematic dependences of all SDMEs on Q (2) and t are presented, as well as the longitudinal-to-transverse rho (0) electroproduction cross-section ratio as a function of Q (2). A small but statistically significant deviation from the hypothesis of s-channel helicity conservation is observed. An indication is seen of a contribution of unnatural-parity-exchange amplitudes; these amplitudes are naturally generated with a quark-exchange mechanism.
Metadaten zuletzt geändert: 19 Dez 2024 12:04