摘要：

Measurements of the proton structure function for and from ZEUS 1995 shifted vertex data are presented. From ZEUS data the slopes at fixed x and for at fixed are derived. For the latter, E665 data are also used. The transition region in is explored using the simplest non-perturbative models and NLO QCD. The data at very low are described successfully by a combination of generalised vector meson dominance and Regge theory. From a NLO QCD fit to ZEUS data the gluon density in the proton is extracted in the range . Data from NMC and BCDMS constrain the fit at large x. Assuming the NLO QCD description to be valid down to , it is found that the sea distribution is still rising at small x and the lowest values whereas the gluon distribution is strongly suppressed.

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