  We study a new nucleon resonance from eta photoproduction, which was observed
at sqrt{s}=1675 MeV with a narrow decay width (~10 MeV) by the Tohoku LNS group
as well as the GRAAL collaboration. Using an effective Lagrangian approach, we
compute differential cross sections for the eta photoproduction. In addition to
N*(1675,1/2+-,3/2+-), we employ six other nucleon resonances, i.e.
N*(1520,1535,1650,1675,1710,1720) and vector meson exchanges which are the most
relevant ones to this reaction process. As a result, we can reproduce the GRAAL
data qualitatively well and observe obvious isospin asymmetry between the
transition magnetic moments of N*(1675): mu_{gamma nn*} >> mu_{gamma pp*},
which indicates that the newly found nucleon resonance may be identified as a
non-strange pentaquark state.

High Energy Physics - Phenomenology