TH Meeting on Particle Physics Phenomenology

Pionic hydrogen in chiral perturbation theory

Name: Pionic hydrogen in chiral perturbation theory
Start: 2002-12-13T14:00:00+01:00
End: 2002-12-13T15:00:00+01:00
Location: CERN

by Edisher LIPARTIA (Lund University)

Friday 13 Dec 2002, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

TH Auditorium

CERN

Description

We investigate the ground-state energy of the pi-p atom (pionic hydrogen) in the framework of QCD+ QED. In particular, we evaluate the strong energy-level shift. We perform the calculation at next-to-leading order in the low-energy expansion in the framework of the relevant effective field theory. The result provides a relation between the strong energy shift and the pion-nucleon S-wave scattering lengths - evaluated in pure QCD - at next-to-leading order in isospin breaking and in the low-energy expansion. We compare our result with available model calculations.