https://doi.org/10.1140/epja/i2007-10390-9
Regular Article - Hadron Physics
Neutron-proton mass difference in isospin-asymmetric nuclear matter
1
Helmholtz-Institut für Strahlen- und Kernphysik (Theorie), Universität Bonn, D-53115, Germany
2
Institut für Kernphysik (Theorie), Forschungszentrum Jülich, D-52425, Jülich, Germany
3
Institute of Nuclear Physics, Academy of Sciences of Uzbekistan, Tashkent-132, Uzbekistan
4
Institute of Physics and Applied Physics, Yonsei University, 120-749, Seoul, Korea
5
Physics Department and Institute of Applied Physics, National University of Uzbekistan, Tashkent-174, Uzbekistan
* e-mail: a.wirzba@fz-juelich.de
Received:
16
May
2007
Accepted:
23
May
2007
Published online:
8
June
2007
Isospin-breaking effects in the baryonic sector are studied in the framework of a medium-modified Skyrme model. The neutron-proton mass difference in infinite, asymmetric nuclear matter is discussed. In order to describe the influence of the nuclear environment on the skyrmions, we include energy-dependent charged and neutral pion optical potentials in the s - and p -wave channels. The present approach predicts that the neutron-proton mass difference is mainly dictated by its strong part and that it strongly decreases in neutron matter.
PACS: 12.39.Fe Chiral Lagrangians – / 13.40.Gp Electromagnetic form factors – / 21.65.+f Nuclear matter –
© Società Italiana di Fisica and Springer-Verlag, 2007
