Coherent proton diffraction dissociation on helium from 46 to 400 GeV

Abstract

Inclusive coherent proton diffraction dissociation on helium has been measured in the four-momentum transfer and missing-mass region $0.04<\mathrm{}\left|t\right|<0.40\mathrm{}$ (${\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$, ${M_X}^2<10\mathrm{}$ ${\mathrm{GeV}}^2$ and for incident proton beam momenta from 46 to 400 GeV/c. We find that the differential cross section $\frac{d^2\sigma }{\mathrm{dt}d{M_X}^2}$ varies slowly with energy, reveals a pronounced peak at ${M_X}^2\simeq 2$ ${\mathrm{GeV}}^2$, and at large masses behaves approximately as $\frac{1}{{M_X}^2}$. The cross section falls exponentially as $\mathrm{}\left|t\right|\mathrm{}$ increases, with a large slope parameter at small momentum transfers and a substantially smaller one at large $\mathrm{}\left|t\right|\mathrm{}$ values, with no clear dip between the two regions as seen in elastic scattering. We compare the experimental $t$ distributions to Glauber-model predictions and find the data provide a sensitive test of the assumptions on the details of the elementary proton diffraction-dissociation amplitudes and on the total cross sections of the diffractively produced states.