Nuclear dependence of high-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="italic">x</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="italic">t</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>hadron and high-τ hadron-pair production in<i>p</i>-<i>A</i>interactions at √<i>s</i>=38.8 GeV

We present a high-statistics, species-identified measurement of the W-to-Be per-nucleon cross-section ratio, ${\mathit{R}}_{\mathrm{W}/\mathrm{B}\mathrm{e}}$, for high-${\mathit{x}}_{\mathit{t}}$ hadrons and high-\ensuremath{\tau} ${\mathit{h}}^{+}$${\mathit{h}}^{\mathrm{\ensuremath{-}}}$ pairs produced in p-A collisions at \ensuremath{\surd}s =38.8 GeV. The data extend to 0.62 in ${\mathit{x}}_{\mathit{t}}$ and 0.39 in \ensuremath{\surd}\ensuremath{\tau} . For single hadrons, ${\mathit{R}}_{\mathrm{W}/\mathrm{B}\mathrm{e}}$ peaks at ${\mathit{p}}_{\mathit{t}}$\ensuremath{\approxeq}5 GeV/c and decreases to \ensuremath{\approxeq}1 for mesons with pt&gt;8 GeV/c. At fixed ${\mathit{p}}_{\mathit{t}}$, ${\mathit{R}}_{\mathrm{W}/\mathrm{B}\mathrm{e}}$ falls with \ensuremath{\surd}s . For symmetric pairs with \ensuremath{\surd}\ensuremath{\tau} &gt;0.28, ${\mathit{R}}_{\mathrm{W}/\mathrm{B}\mathrm{e}}$=0.84\ifmmode\pm\else\textpm\fi{}0.02\ifmmode\pm\else\textpm\fi{}0.07, suggesting a nuclear suppression of high-z fragmentation. ${\mathit{R}}_{\mathrm{W}/\mathrm{B}\mathrm{e}}$ increases with ${\mathit{p}}_{\mathrm{out}}$, indicative of constituent multiple scattering.