Abstract

The production of jets is studied in deep-inelastic e + p scattering at low negative four momentum transfer squared 5<Q 2<100 GeV2 and at inelasticity 0.2<y<0.7 using data recorded by the H1 detector at HERA in the years 1999 and 2000, corresponding to an integrated luminosity of 43.5 pb−1. Inclusive jet, 2-jet and 3-jet cross sections as well as the ratio of 3-jet to 2-jet cross sections are measured as a function of Q 2 and jet transverse momentum. The 2-jet cross section is also measured as a function of the proton momentum fraction ξ. The measurements are well described by perturbative quantum chromodynamics at next-to-leading order corrected for hadronisation effects and are subsequently used to extract the strong coupling α s .