# A measurement of the $t$ dependence of the helicity structure of diffractive $\rho$ meson electroproduction at HERA

Abstract : The helicity structure of the diffractive electroproduction of rho mesons, e + p -> e + rho + Y, is studied in a previously unexplored region of large four-momentum transfer squared at the proton vertex, t: 0 < t' < 3 GeV^2, where t' = |t| - |t|_min. The data used are collected with the H1 detector at HERA in the kinematic domain 2.5 < Q^2 < 60 GeV^2, 40 < W < 120 GeV. No t dependence of the r^04_00 spin density matrix element is found. A significant t dependent helicity non-conservation from the virtual photon to the rho meson is observed for the spin density matrix element combinations r^5_00+2r^5_11 and r^1_00+2r^1_11. These t dependences are consistently described by a perturbative QCD model based on the exchange of two gluons.
Document type :
Journal articles

Cited literature [3 references]

http://hal.in2p3.fr/in2p3-00011715
Contributor : Magali Damoiseaux <>
Submitted on : Monday, July 22, 2002 - 5:42:37 PM
Last modification on : Wednesday, April 7, 2021 - 3:26:01 PM
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### Identifiers

• HAL Id : in2p3-00011715, version 1

### Citation

C. Adloff, V. Andreev, B. Andrieu, T. Anthonis, V. Arkadov, et al.. A measurement of the $t$ dependence of the helicity structure of diffractive $\rho$ meson electroproduction at HERA. Physics Letters B, Elsevier, 2002, 539, pp.25-39. ⟨in2p3-00011715⟩

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