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The Q^2-Dependence of Nuclear Transparency for Exclusive $ρ^0$ Production

HERMES Collaboration·A. Airapetian
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Abstract

Exclusive coherent and incoherent electroproduction of the $ρ^0$ meson from $^1$H and $^{14}$N targets has been studied at the HERMES experiment as a function of coherence length ($l_c$), corresponding to the lifetime of hadronic fluctuations of the virtual photon, and squared four-momentum of the virtual photon ($-Q^2$). The ratio of $^{14}$N to $^1$H cross sections per nucleon, known as nuclear transparency, was found to increase (decrease) with increasing coherence length for coherent (incoherent) $ρ^0$ electroproduction. For fixed coherence length, a rise of nuclear transparency with $Q^2$ is observed for both coherent and incoherent $ρ^0$ production, which is in agreement with theoretical calculations of color transparency.

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HERMES Collaboration, A. Airapetian. 2002-09-26. The Q^2-Dependence of Nuclear Transparency for Exclusive $ρ^0$ Production. https://doi.org/10.1103/physrevlett.90.052501

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