2018 Impact factor 4.843
Particles and Fields
Eur. Phys. J. C 6, 603-627
DOI 10.1007/s100529901051

Exclusive electroproduction of $\rho^0$ and $J/\psi$ mesons at HERA

ZEUS Collaboration

J. Breitweg - et al.

Argonne National Laboratory, Argonne, IL, USA

Received: 20 August 1998 / Published online: 14 January 1999

Abstract
Exclusive production of $\rho^0$ and $J/\psi$ mesons in e+p collisions has been studied with the ZEUS detector in the kinematic range 0.25 < Q2 < 50 $\mathrm{{\rm Ge}\kern-1.pt{\rm V}}^2$, 20 < W < 167 GeV for the $\rho^0$ data and 2 < Q2 < 40 $\mathrm{{\rm Ge}\kern-1.pt{\rm V}}^2$, 50 < W < 150 GeV for the $J/\psi$ data. Cross sections for exclusive $\rho^0$ and $J/\psi$production have been measured as a function of Q2, W and t. The spin-density matrix elements r0400, r11-1 and Re$\:r^{5}_{10}$have been determined for exclusive $\rho^0$ production as well as r0400 and r041-1 for exclusive $J/\psi$ production. The results are discussed in the context of theoretical models invoking soft and hard phenomena.


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