Hadronic cross-section fluctuations and proton coherent diffractive dissociation on helium

Abstract

The differential cross-section of inelastic coherent diffractive dissociation off nuclei $p+{}^4$He $\to X+{}^4$He is expressed in terms of the relative cumulants of the cross-section distribution $P_N(\sigma )$. The theoretical result for the ratio $r=(\frac{d{\sigma }_{diff}}{dt}{)}_{t=0}^{pHe}/(\frac{d{\sigma }_{diff}}{dt}{)}_{t=0}^{pp}=6.8÷7.6$ is close to the value $r=7.1\pm 0.75$ which we extracted from the FNAL data. These are the only $A>2$ data of this kind. The comparison provides the first confirmation of the cross-section fluctuation approach to the description of the absolute value of the inelastic diffraction cross-section off nuclei. It provides also a new constraint on the first 4 cumulants of the cross-section distribution.

Comments: 10 pages, revtex