Cumulative particle production in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Ne</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>20</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>interactions at 300 GeV
Аннотация
The experimental data on multiplicity, correlations, and inclusive spectra of protons, ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ mesons, $\ensuremath{\gamma}$, neutral strange particles, and fast neutrons produced in the backward (${\ensuremath{\theta}}_{\mathrm{lab}}>90\ifmmode^\circ\else\textdegree\fi{}$) hemisphere in the laboratory system are presented for $p^{20}\mathrm{Ne}$ interactions and compared with predictions generated by the additive quark model, the Lund model, and the dual parton model. Whereas all these models adequately reproduce the $\ensuremath{\pi}$ and $\ensuremath{\gamma}$ data, only the additive quark model is consistent with the proton data. Strong evidence for the production of backward-emitted isobars is presented and lower limits (corresponding to ${\ensuremath{\theta}}_{\mathrm{lab}}^{\ensuremath{\pi}}>90\ifmmode^\circ\else\textdegree\fi{}$) are measured to be $\ensuremath{\sigma}({\ensuremath{\Delta}}^{++})=6.6\ifmmode\pm\else\textpm\fi{}1.1$ mb, $\ensuremath{\sigma}({\ensuremath{\Delta}}^{0})=8.1\ifmmode\pm\else\textpm\fi{}1.0$ mb, and $\ensuremath{\sigma}({N}^{*}(1440))=3.3\ifmmode\pm\else\textpm\fi{}0.6$ mb. These backward isobars are responsible for \ensuremath{\sim}30% of the backward ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$. The evidence is much weaker for backward ${\ensuremath{\rho}}^{0}[\ensuremath{\sigma}({\ensuremath{\rho}}^{0})={0.81}_{\ensuremath{-}0.81}^{+0.21}\mathrm{mb}]$ and ${\ensuremath{\omega}}^{0}[\ensuremath{\sigma}({\ensuremath{\omega}}^{0})={0.69}_{\ensuremath{-}0.69}^{+0.19}\mathrm{mb}]$ at 95% C.L. Evidence of correlations between backward, cumulative protons and forward protons is presented. Using these correlations we present evidence for absorption of pions by quasi-two-nucleon systems within the neon nucleus: $\ensuremath{\sigma}(\ensuremath{\pi}+``b"\ensuremath{\rightarrow}pp)=18.6\ifmmode\pm\else\textpm\fi{}3.0$ mb and $\ensuremath{\sigma}(\ensuremath{\pi}+``b"\ensuremath{\rightarrow}\ensuremath{\Delta}p)=2.7\ifmmode\pm\else\textpm\fi{}1.6$ mb.