Abstract | A measurement of the longitudinal diffractive structure function
F_L^D at low Q^2 using the H1 detector at HERA is presented.
Measurements of the diffractive cross-section
at centre of mass energies \sqrt{s} of 225 and 252 GeV
in the Q^2 range of [2.5; 7] GeV^2, using HERA data taken in 2007,
are combined
with a published measurement at $\sqrt{s}$ of 300 GeV.
The structure function F_L^D is extracted from these cross-sections
at high values of inelasticity y.
The measured values of F_L^D are compared with extrapolations of NLO QCD fits to published data,
where the fits only included data with Q^2 > 8.5 GeV^2. |