6533b871fe1ef96bd12d2631
RESEARCH PRODUCT
The new FL measurement from HERA and the dipole model
Otto NachtmannCarlo EwerzAndreas Von ManteuffelAndreas Von ManteuffelAndré Schöningsubject
PhysicsNuclear and High Energy PhysicsHigh Energy Physics::PhenomenologyStructure functionFOS: Physical sciencesHERADipole modelHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)High Energy Physics - PhenomenologyCross section (physics)DipoleTheoretical physicsHigh Energy Physics - Phenomenology (hep-ph)Saturation (graph theory)High Energy Physics::ExperimentCharm (quantum number)description
From the new measurement of F_L at HERA we derive fixed-Q^2 averages . We compare these with bounds which are rigorous in the framework of the standard dipole picture. The bounds are sharpened by including information on the charm structure function F_2^(c). Within the experimental errors the bounds are respected by the data. But for 3.5 GeV^2 <= Q^2 <= 20 GeV^2 the central values of the data are close to and in some cases even above the bounds. Data on F_L/F_2 significantly exceeding the bounds would rule out the standard dipole picture at these kinematic points. We discuss, furthermore, how data respecting the bounds but coming close to them can give information on questions like colour transparency, saturation and the dependencies of the dipole-proton cross section on the energy and the dipole size.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-01-30 | Physics Letters B |