Thursday, April 18, 2013, 16:00
WHGA/Auditorium
D. Gotta, Institut für Kernphysik and JCHP
Abstract:
Ground-state level shift and X-ray line broadening in pionic hydrogen
give access to the two independent pion-nucleon scattering lengths,
where the pionic deuterium level shift provides a mandatory constraint.
In addition, pion threshold production in nucleon-nucleon reactions is
quantifiable with high precision from the deuterium level broadening.
However, acceleration during the de-excitation cascade of such
electrically neutral exotic atoms considerably complicates analyses of
the X-ray line shapes and, therefore was studied in the purely
electromagnetic twin system muonic hydrogen.
The experiments were performed at the high intensity πE5 beam line at
PSI by using a high-resolution crystal spectrometer. Results are
discussed in the context of recent theoretical efforts within the
approach of chiral perturbation theory and atomic cascade.