Abstract | New results on normalised inclusive jet, di-jet and trijet differential
cross sections in neutral current deep-inelastic ep scattering (DIS) based
on a regularised unfolding procedure are presented. Detector effects
like acceptance and migrations as well as statistical correlations
between the multi-jets and the inclusive DIS events are taken into
account in this procedure. The DIS phase space of this measurement
with the H1 detector is given by the virtuality of the exchanged boson
(gamma*,Z^0) 150 < Q^2 < 15000 GeV^2 and the inelasticity of the
interaction 0.2 < y < 0.7. The jets are reconstructed in the Breit
frame of reference using the k_t jet algorithm. In all cases the jet
pseudorapidities in the laboratory frame are required to be in the
range -1.0 < eta_lab < 2.5. For inclusive jets the transverse momenta
in the Breit frame are 7 < P_T < 50 GeV. The di-jet and tri-jet phase
space are defined by requiring 5 < P_T,i < 50 GeV, and the invariant
mass of the two leading jets M_1,2 > 16 GeV. Compared to a previously
published result on normalised multi-jet cross sections, the new features
are an extended range in jet pseudorapidity, an improved hadronic energy
scale uncertainty of 1% and the adoption of a regularised unfolding
procedure. The unfolded normalised jet cross sections are compared to
QCD calculations at NLO and values for the strong coupling alpha_s(M_Z)
are extracted. |