Dr. Pawel Sopicki (INP Cracow)
The production of inclusive jets as well as of dijet and trijet topologies is investigated at HERA. Both the H1 and the ZEUS experiment have determined the corresponding cross sections with improved experimental precision, compared to previous measurements. For both experiments, a hadronic energy scale uncertainty as small as 1% is reached. The value of the strong coupling constant alpha_s(M_Z) is extracted and its running is probed. Using topologies involving high track multiplicities and an associated jets, the H1 data are used to search for the production and decay of QCD instantons.