Ja n 20 07 K ∗ 0 and φ Meson Production in Proton-Nucleus Interactions at √ s = 41 . 6

The inclusive production cross sections of the strange vector mesons K, K ∗0 , and φ have been measured in interactions of 920 GeV protons with C, Ti, and W targets with the HERA-B detector at the HERA storage ring. Differential cross sections as a function of rapidity and transverse momentum have been measured in the central rapidity region and for transverse momenta up to pT = 3.5 GeV/c. The atomic number dependence is parametrised as σpA = σpN ∗ A, where σpN is the proton-nucleon cross section. Within the phase space accessible, α(K) = 0.86 ± 0.03, α(K̄) = 0.87 ± 0.03, and α(φ) = 0.96 ± 0.02. The total proton-nucleon cross sections, determined by extrapolating the differential measurements to full phase space, are σpN→K∗0 = (5.06 ± 0.54) mb, σpN→K̄∗0 = (4.02 ± 0.45) mb, and σpN→φ = (1.17 ± 0.11) mb. For all resonances the Cronin effect is observed; compared to the measurements of Cronin et al. for K mesons, the measured values of α for φ mesons coincide with those of K mesons for all transverse momenta, while the enhancement for K/K ∗0 mesons is smaller.