Exclusive electroproduction of two pions at HERA

Link:
Erscheinungsjahr:
2012
Medientyp:
Text
Schlagworte:
  • Physics
  • Physics
Beschreibung:
  • The exclusive electroproduction of two pions in the mass range 0.4 < M-pi pi < 2.5 GeV has been studied with the ZEUS detector at HERA using an integrated luminosity of 82 pb(-1). The analysis was carried out in the kine-matic range of 2 < Q(2) < 80 GeV2, 32 < W < 180 GeV and vertical bar t vertical bar < 0.6 GeV2, where Q(2) is the photon virtuality, W is the photon-proton centre-of-mass energy and t is the squared four-momentum transfer at the proton vertex. The two-pion invariant-mass distribution is interpreted in terms of the pion electromagnetic form factor, vertical bar F(M-pi pi)vertical bar, assuming that the studied mass range includes the contributions of the rho, rho' and rho `' vector-meson states. The masses and widths of the resonances were obtained and the Q(2) dependence of the cross-section ratios sigma(rho ` -> pi pi)/sigma(rho) and sigma (rho `' -> pi pi)/sigma(rho) was extracted. The pion form factor obtained in the present analysis is compared to that obtained in e(+) e(-) -> pi(+) pi(-).
Lizenz:
  • info:eu-repo/semantics/openAccess
Quellsystem:
Forschungsinformationssystem der UHH

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Quelldatensatz
oai:www.edit.fis.uni-hamburg.de:publications/050a5495-07d1-4227-9c8e-199e84e453dc