We review the description of the lowest-energy nucleon excitation—the Δ (1232)-resonance.
Much of the recent experimental effort has been focused on the precision measurements of …

Photoproduction of mesons is an excellent tool for the study of nucleon resonances.
Complementary to pion induced reactions, photoproduction on the free proton contributes to …

We perform a systematic study of the electromagnetic properties of exotic states to shed light
on their nature, which is still controversial and not fully understood. The magnetic dipole and …

The reaction γ p→ π 0 γ′ p has been measured with the TAPS calorimeter at the Mainz
Microtron accelerator facility MAMI for energies between s= 1221–1331 M e V. The cross …

We present a calculation of the leading SU (3)-breaking O (p 3) corrections to the
electromagnetic moments and charge radius of the lowest-lying decuplet resonances in …

To shed light on the nature of the controversial and not yet fully understood exotic states, we
are carrying out a systematic study of their electromagnetic properties. The magnetic …

An expansion of the electromagnetic form factors of the nucleon and Δ (1232) in small
momentum transfer and pion mass is performed in a manifestly covariant EFT framework …

The electromagnetic form factors of the Δ baryon are evaluated within the framework of a
covariant spectator quark model, where S-and D-states are included in the Δ wave function …

We derive the on-shell form of amplitudes containing two external currents with a single
hadron in the initial state and two hadrons in the final state, denoted as 1+ J→ 2+ J. This …

We present a theoretical study of the radiative pion photoproduction on the nucleon (γ N→ π
N γ′) in the Δ-resonance region, with the aim to determine the magnetic dipole moment …