https://doi.org/10.1140/epjc/s2004-01859-4
theoretical physics
Spectrum and decays of kaonic hydrogen
1
Helmholtz-Institut für Strahlen- und Kernphysik (Theorie), Universität Bonn, Nußallee 14-16, 53115, Bonn, Germany
2
Institut für Kernphysik (Theorie), Forschungszentrum Jülich, 52425, Jülich, Germany
Received:
7
March
2004
Published online: 18 May 2004
By using the non-relativistic effective Lagrangian approach to bound states, a complete expression for the isospin-breaking corrections to the energy levels and the decay widths of kaonic hydrogen is obtained up-to-and-including 
in QCD. It is demonstrated that, although the leading-order corrections at 
emerging due to the unitarity cusp are huge, they can be expressed solely in terms of the KN S-wave scattering lengths. Consequently, at leading order, it is possible to derive parameter-free modified Deser-type relations, which can be used to extract the scattering lengths from the hadronic atom data.
© Springer-Verlag, 2004
