Deep inelastic collisions

Illustration of a damped (deep inelastic) collision. The projectile trajectory is shown by the heavy curve and the extension of the original Coulomb-scattering trajectory by dashed lines. During the rotation angle of the dinuclear complex, A0 = — exp/ a neck is formed between the reacting... 

Besides the distance between the nuclear centers, R, the mass transfer, a = A — A2)/ A + A2) and dynamic deformations of nuclear surfaces, fi, play a most important role in fusion-fission and deep inelastic processes of low energy heavy-ion collisions. The corresponding multi-dimensional adiabatic potential energy surface was calculated here within the semi-empirical two-core approach [68] based... 

The classification scheme in O Fig. 3.35 becomes simplified for lighter projectiles, for which fusion and simple surface reactions are the principal exit chaimels at low relative bombarding energies. For very heavy projectiles, the damped-collision (deep-inelastic)... 

If we consider reactions initiated in pp collisions we recognize in (17.4.28) the distributions xqj x),xqj x) that appeared in the formulae for the deep inelastic structure function F2(x) [see (16.1.7)]. If these are known from the study of deep inelastic scattering, then the Drell-Yan cross-section is completely determined. There are difficulties, however, that we shall discuss later. 

To test the detailed predictions (17.4.28) in proton-proton collisions is difficult since one requires the distribution function for antiquarks inside nucleons. These, it will be recalled, are important only at small x in deep inelastic scattering and, consequently, are difficult to determine accurately. On the other hand, in pp collisions there is a strong source of antiquarks in the p and one would take (x) = (x) so this will be an... 

Photoelectron spectroscopy of valence and core electrons in solids has been useful in the study of the surface properties of transition metals and other solid-phase materials. When photoelectron spectroscopy is performed on a solid sample, an additional step that must be considered is the escape of the resultant photoelectron from the bulk. The analysis can only be performed as deep as the electrons can escape from the bulk and then be detected. The escape depth is dependent upon the inelastic mean free path of the electrons, determined by electron-electron and electron-phonon collisions, which varies with photoelectron kinetic energy. The depth that can be probed is on the order of about 5-50 A, which makes this spectroscopy actually a surface-sensitive technique rather than a probe of the bulk properties of a material. Because photoelectron spectroscopy only probes such a thin layer, analysis of bulk materials, absorbed molecules, or thin films must be performed in ultrahigh vacuum (<10 torr) to prevent interference from contaminants that may adhere to the surface. 

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