Measurement of heavy-quark jet photoproduction at HERA
  Photoproduction of beauty and charm quarks in events with at least two jets has been measured with the ZEUS detector at HERA using an integrated luminosity of 133 $pb^{-1}$. The fractions of jets containing b and c quarks were 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 jet transverse momentum, $p_{T}^{\text{jet}}$, and pseudorapidity, $\eta^{\text{jet}}$, were measured. The data are compared with previous measurements and are well described by next-to-leading-order QCD predictions. 
ZEUS Collaboration: H. Abramowicz, I. Abt, L. Adamczyk, M. Adamus, R.   Aggarwal, S. Antonelli, P. Antonioli, A. Antonov, M....
hep-ex