Inclusive production of φ-mesons in neutron-proton interaction at 30-70 GeV/c

A signal of theΦ-K+K− decays has been observed in neutron-hydrogen interactions at energies of 30–70 GeV in an experiment using the BIS-2 spectrometer. The longitudinal momentum spectrum in the forward region,xF<0·1 atpT<1 GeV/c, can be well described by a power law dependence (1−xF)N withN=4·28±0·42. Thep T 2 -spectrum has been parametrized by the exp(−Bp T 2 ) law with the exponentB=(3·02±0·55) (GeV/c)−2. The extrapolation of the measured cross section to the full kinematic region yields a value of (220±85) Μb in agreement with measurements from the proton beams.