The Role of Mesonic Degrees of Freedom in Scattering of Hardrons on Nuclei

The Glauber multiple scattering is reviewed, its experimental success described and its essential approximations enumerated. A simple harmonic oscillator model of mesonic degrees of freedom is constructed and Glauber scattering evaluated. The difficulties in fitting experimental amplitude data varying over many decades as a function of momentum transfer q2 are emphasized. It is then concluded that the introduction of effective nucleonic parameters for computation of nuclear structures are sufficient to mask the influence of mesonic degrees of freedom. However, hadronic effects such as 1) low cross-sections for composite systems propagating through nuclear matter, 2) low multiplicities for hadronic production processes inside nuclear matter (i.e. lack of cascading), and 3) very rapid variations of high pT production cross sections with nuclear mass, indicate a region of serious lack of understanding of basic facts in this field in spite of numerous explanatory models.