Leif Jönsson
Professor emeritus
Measurement of the diffractive longitudinal structure function F(L)(D) at HERA
Author
Summary, in English
First measurements are presented of the diffractive cross section sigma(ep) -> eXY at centre-of-mass energies root s of 225 and 252 GeV, together with a precise new measurement at root s of 319 GeV, using data taken with the H1 detector in the years 2006 and 2007. Together with previous H1 data at root s of 301 GeV, the measurements are used to extract the diffractive longitudinal structure function F(L)(D) in the range of photon virtualities 4.0 <= Q(2) <= 44.0 GeV(2) and fractional proton longitudinal momentum loss 5 x 10(-4) <= x(P) <= 3 x 10(-3). The measured F(L)(D) is compared with leading twist predictions based on diffractive parton densities extracted in NLO QCD fits to previous measurements of diffractive Deep-Inelastic Scattering and with a model which additionally includes a higher twist contribution derived from a colour dipole approach. The ratio of the diffractive cross section induced by longitudinally polarised photons to that for transversely polarised photons is extracted and compared with the analogous quantity for inclusive Deep-Inelastic Scattering.
Department/s
- Particle and nuclear physics
Publishing year
2011
Language
English
Publication/Series
European Physical Journal C. Particles and Fields
Volume
71
Issue
12
Document type
Journal article
Publisher
Springer
Topic
- Subatomic Physics
Status
Published
ISBN/ISSN/Other
- ISSN: 1434-6044