| Abstract | The cross section for the diffractive deep-inelastic scattering process
$ep \to e X p$ is measured, with the leading final state proton
detected in the H1 Forward Proton Spectrometer, using data collected
at HERA-2 in years 2005-2007. The analysed data sample corresponds to
an integrated luminosity of 170 pb^-1. The data cover the range
$\xpom <0.1$ in fractional proton longitudinal momentum loss,
$0.1 < |t| < 0.7 GeV^{-2}$ in squared four-momentum transfer at the
proton vertex, $4 < Q^2 < 125 GeV^2$ in photon virtuality and
$0.001 < \beta = x / \xpom < 1$, where $x$ is the Bjorken scaling
variable. The cross section is measured differentially in
$\xpom, \beta$ and $Q^2$. The data are compared with QCD predictions
at next-to-leading order based on diffractive parton distribution
functions previously extracted from measurements of inclusive
diffractive deep-inelastic scattering. |
