The results of the SERP-E-184 experiment at the U-70 accelerator (IHEP, Protvino) are presented. Interactions of the 70 GeV proton beam with C, Si and Pb targets were studied to detect decays of charmed $D^0$, $overline D^0$, $D^+$, $D^-$ mesons and $Lambda _c^+$ baryon near their production threshold. Measurements of lifetimes and masses are shown a good agreement with PDG data. The inclusive cross sections of charm production and their A-dependencies were obtained. The yields of these particles are compared with the theoretical predictions and the data of other experiments. The measured cross section of the total open charm production ($sigma _{mathrm {tot}}(coverline c)$ = 7.1 $pm $ 2.3(stat) $pm $1.4(syst) $mu $b/nucleon) at the collision c.m. energy $sqrt {s}$ = 11.8 GeV is well above the QCD model predictions. The contributions of different species of charmed particles to the total cross section of the open charm production in proton-nucleus interactions vary with energy.
تحميل البحث