Angle-differential cross sections for Rayleigh scattering of highly linearly polarized hard x rays on Au atoms

Elastic scattering of linearly polarized hard x - rays

Experimental verification of Rayleigh scattering cross sections.

The cavity-ringdown technique is applied to measure Rayleigh extinctions of Ar, N(2), and SF(6) in the 560-650-nm region at 294 K. It is shown that experimental and calculated Rayleigh scattering cross sections agree within an experimental uncertainty of 1% (for SF(6), 3%).

Energy and angle differential cross sections

Energy and angle differential cross sections for the electron-impact double ionization of helium are calculated using a non-perturbative time-dependent close-coupling method. Collision probabilities are found by the projection of a time-evolved nine-dimensional coordinate space wavefunction onto fully antisymmetric products of spatial and spin functions representing three outgoing Coulomb waves...

Determining the Factorizability of Hard Scattering Cross-Sections

The rules of soft-collinear effective theory can be used naı̈vely to write hard scattering cross-sections as convolutions of separate hard, jet, and soft functions. We describe an intuitive method to determine, at a given order in perturbation theory, whether these functions are truly infrared safe or not and, thus, whether or not the cross-sections factorize. Using angularity distributions as a...

Infrared Safety in Factorized Hard Scattering Cross-Sections

The rules of soft-collinear effective theory can be used naı̈vely to write hard scattering cross-sections as convolutions of separate hard, jet, and soft functions. One condition required to guarantee the validity of such a factorization is the infrared safety of these functions in perturbation theory. Using e+e− angularity distributions as an example, we propose and illustrate an intuitive meth...