Skobeltsyn Institute of Nuclear Physics
Lomonosov Moscow State University

Magnetic moments of spin 1/2 charm baryons are reevaluated in
framework of
Heavy Hadron Chiral Perturbation Theory (HHCPT). NRQM, broken
SU(4)_{f} unitary symmetry and quark-biquark models are
considered as tree-level approximation. Calculations of
one-loop contributions to magnetic moments are performed
in terms of SU(4)_{f} couplings of charm baryons to
Goldstone bosons. The relation between HHCPT results and those
of NRQM and unitary symmetry model is discussed.
It is shown that for sextet spin 1/2 charm baryons with the
one-loop corrections taken into account old-fashioned NRQM picture
effectively emerges leading to the same relations between
magnetic moments. Similar conclusion is made for antitriplet
spin 1/2 charm baryons.
Unitary symmetry part of the one-loop calculations
is performed in detail for every charm baryon from 6-plet and
3^{*}-plet and the corresponding diagrams are given.
Tree-level calculations are given in some detail.
Relation with the results of some recent works on
magnetic moments of ordinary and charm baryons is discussed.