Experimental results from hera

Abstract First results on the neutron spin structure function g n 1 havebeen presented by HERMES. Precise F2 measurements have been performed by H1 and ZEUS over a wide range in x from 10−5 to 0.3 and in Q2 from 0.16 to 5000 GeV2. F2, as well as the gluon momentum density xg(x, Q2), extracted from (dF2)/d ln Q2) exhibit a fast rise as x 0 which show that the proton's quark and gluon densities at small x are large. The data on F2 as well as the first measurements of the longitudinal structure function FL and the charm contribution to F2 are in agreement with DGLAP evolution. Comparison of results obtainedfor very small values of Q2 with theoretical models indicate that for x < 10−2 the transition from soft to hard scattering occurs at Q2 values below ≈ 1 GeV2. The DIS NC and CC measurements have been extended to large values of Q2 ≈ M2 W, M2 Z. For Q2 above M2 W the weak force is found to have similar strength as the electromagnetic one. Combining data on e+p deep inelastic scattering from 1994–97 running ...