https://doi.org/10.1140/epjc/s2005-02346-2
experimental physics
Measurement of inelastic 
production in deep inelastic scattering at HERA
The inelastic production of mesons in ep collisions has been studied with the ZEUS detector at HERA using an integrated luminosity of 
. The mesons were identified using the decay channel 
. The measurements were performed in the kinematic range 
, 
, 0.2 < z < 0.9 and 
, where Q
2 is the virtuality of the exchanged photon, W is the photon-proton centre-of-mass energy, z is the fraction of the photon energy carried by the meson in the proton rest frame and 
is the rapidity of the in the laboratory frame. The measured cross sections are compared to theoretical predictions within the non-relativistic QCD framework including colour-singlet and colour-octet contributions, as well as to predictions based on the k
T
-factorisation approach. Calculations of the colour-singlet process generally agree with the data, whereas inclusion of colour-octet terms spoils this agreement.
© Springer-Verlag, 2005
