High-Q(2) neutral current cross sections in e(+)p deep inelastic scattering at root s=318 GeV

Cross sections for e(+)p neutral current deep inelastic scattering have been measured at a center-of-mass energy of roots=318 GeV with the ZEUS detector at HERA using an integrated luminosity of 63.2 pb(-1). The double-differential cross section, d(2)sigma/dxdQ(2), is presented for 200 GeV(2)<Q(2)<30 000 GeV(2) and for 0.005<x<0.65. The single-differential cross sections dsigma/dQ(2), dsigma/dx and dsigma/dy are presented for Q(2)>200 GeV(2). The effect of Z-boson-exchange is seen in dsigma/dx measured for Q(2)>10 000 GeV(2). The data presented here were combined with ZEUS e(+)p neutral current data taken at roots=300 GeV and the structure function F(2)(em) was extracted. All results agree well with the predictions of the Standard Model.