Alex Feller and Javier Trujillo Bueno

The chapter "Scattering physics and Hanle-Zeeman diagnostics" of the EST Scientific Requirement Document (SRD) collects a series of observing programs (OPs) focused on spectral lines that we consider of highest priority because they produce scattering polarization signals of particular interest either because of their diagnostic potential for the investigation of the magnetism of the solar atmosphere (especially in domains that are not accessible through the Zeeman effect), or because their theoretical interpretation is still unclear. The OPs are specifically designed so as to exploit the specific advantages of the EST, in particular the combination of high polarimetric sensitivity and high spatio-temporal resolution. In this talk, we review the status of this chapter of the SRD, and we present in detail some of the observing programs that have been proposed so far.