Dokumentenart: | Artikel | ||||
---|---|---|---|---|---|
Titel eines Journals oder einer Zeitschrift: | Physics Letters B | ||||
Verlag: | ELSEVIER SCIENCE BV | ||||
Ort der Veröffentlichung: | AMSTERDAM | ||||
Band: | 599 | ||||
Nummer des Zeitschriftenheftes oder des Kapitels: | 3-4 | ||||
Seitenbereich: | S. 212-222 | ||||
Datum: | 2004 | ||||
Institutionen: | Physik > Institut für Theoretische Physik > Lehrstuhl Professor Schäfer > Arbeitsgruppe Andreas Schäfer | ||||
Identifikationsnummer: |
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Stichwörter / Keywords: | GENERALIZED PARTON DISTRIBUTIONS; VECTOR-MESON PRODUCTION; MONTE-CARLO GENERATOR; DENSITY MATRIX; P(0) MESONS; 2 PIONS; SCATTERING; QCD; | ||||
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: | 71248 |
Zusammenfassung
Hard exclusive electroproduction of pi(+) pi(-) pairs off hydrogen and deuterium targets has been studied by the HERMES experiment at DESY Legendre moments (P-1) and (P-3) of the angular distributions of pi(+) mesons in the center-of-mass frame of the pair have been measured for the first time. Their dependence on the pi(+) pi(-) invariant mass can be understood as being due to the interference ...
Zusammenfassung
Hard exclusive electroproduction of pi(+) pi(-) pairs off hydrogen and deuterium targets has been studied by the HERMES experiment at DESY Legendre moments (P-1) and (P-3) of the angular distributions of pi(+) mesons in the center-of-mass frame of the pair have been measured for the first time. Their dependence on the pi(+) pi(-) invariant mass can be understood as being due to the interference between relative P-wave (isovector) and S-, D-wave (isoscalar) states of the two pions. The increase in magnitude of (P-1) as Bjorken x increases is interpreted in the framework of generalized parton distributions as an enhancement of flavour non-singlet qq exchange for larger values of x, which leads to a sizable admixture of isoscalar and isovector pion pairs. In addition, the interference between P-wave and D-wave states separately for transverse and longitudinal pion pairs has been studied. The data indicate that in the f(2)(1270) region at <Q(2)> = 3 GeV2 higher-twist effects can be as large as the leading-twist longitudinal component. (C) 2004 Published by Elsevier B.V.
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