A measurement and QCD analysis of the proton structure function F2 (x, Q2) at HERA

Abstract A new measurement of the proton structure function F 2 ( x , Q 2 ) is reported for momentum transfers squared Q 2 between ].5 GeV 2 and 5000 GeV 2 and for Bjorken x between 3 · 10 −5 and 0.32 using data collected by the HERA experiment H1 in 1994. The data represent an increase in statistics by a factor of ten with respect to the analysis of the 1993 data. Substantial extension of the kinematic range towards low Q 2 and x has been achieved using dedicated data samples and events with initial state photon radiation. The structure function is found to increase significantly with decreasing x, even in the lowest accessible Q 2 region. The data are well described by a Next to Leading Order QCD fit and the gluon density is extracted.