K^*0 and φ meson production in proton–nucleus interactions at $\sqrt{s}=41.6\text{GeV}$

Abstract

The inclusive production cross sections of the strange vector mesons K^*0, K̄^*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 p_T = 3.5 GeV/c. The atomic number dependence is parametrised as σ_pA=σ_pN*A^α, where σ_pN is the proton–nucleon cross section. Within the phase space accessible, α(K^*0)=0.86±0.03, α(K̄^*0)=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 σ_pN→K*0=(5.06±0.54) mb, σ_pN→K̄*0=(4.02±0.45) mb, and σ_pN→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^*0/K̄^*0 mesons is smaller.