Measurement of beauty and charm production in deep inelastic scattering at HERA and measurement of the beauty-quark mass

The production of beauty and charm quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared 5 < Q(2) < 1000 GeV2 using an integrated luminosity of 354 pb(-1). The beauty and charm content in events with at least one jet have been extracted using the invariant mass of charged tracks associated with secondary vertices and the decay-length significance of these vertices. Differential cross sections as a function of Q(2), Bjorken x, jet transverse energy and pseudorapidity were measured and compared with next-to-leading-order QCD calculations. The beauty and charm contributions to the proton structure functions were extracted from the double-differential cross section as a function of x and Q(2). The running beauty-quark mass, m(b) at the scale m(b) , was determined from a QCD fit at next-to-leading order to HERA data for the first time and found to be m(b) (m(b)) = 4.07 +/- 0.14 (fit)(-0.07)(+0.01) (mod.)(-0.00)(+0.05) (param.)(-0.05)(+0.08) (theo.) GeV.