115 citations · 418 across the 16 of their papers we have counts for
16 papers
Non-coplanar magnetism, topological density wave order and emergent symmetry at half-integer filling of moiré Chern bands
Patrick H. Wilhelm, Thomas C. Lang, Mathias S. Scheurer +1
Twisted double- and mono-bilayer graphene are graphene-based moiré materials hosting strongly correlated fermions in a gate-tunable conduction band with a topologically non-trivial…
Laser-probing the rotational cooling of molecular ions by electron collisions
Ábel Kálosi, Manfred Grieser, Robert von Hahn +9
We present state-selected measurements of rotational cooling and excitation rates of CH molecular ions by inelastic electron collisions. The experiments are carried out at the…
Interplay of Fractional Chern Insulator and Charge-Density-Wave Phases in Twisted Bilayer Graphene
Patrick Wilhelm, Thomas C. Lang, Andreas M. Läuchli
We perform an extensive exact diagonalization study of interaction driven insulators in spin- and valley-polarized moiré flat bands of twisted bilayer graphene aligned with its hex…
Photoionization of metastable heliumlike C4+(1s 2s 3S1) ions: Precision study of intermediate doubly excited states
A. Müller, E. Lindroth, S. Bari +10
In a joint experimental and theoretical endeavour, photoionization of metastable C4+(1s 2s 3S1) ions via intermediate levels with hollow, double-K-vacancy configurations 2s2p, 2s3p…
The Cryogenic Storage Ring CSR
Robert von Hahn, Arno Becker, Felix Berg +41
An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed and put into operatio…
Explicit pionic degrees of freedom in deuteron photodisintegration in the Delta-resonance region
M. Schwamb, H. Arenhoevel, P. Wilhelm +1
Photodisintegration of the deuteron above pi-threshold is studied in a coupled channel approach including N-Delta- and pi-d-channels with pion retardation in potentials and exchang…
On the Gerasimov-Drell-Hearn sum rule for the deuteron
H. Arenhoevel, G. Kress, R. Schmidt +1
The Gerasimov-Drell-Hearn sum rule is evaluated for the deuteron by explicit integration up to 550 MeV including contributions from the photodisintegration channel and from coheren…
Meson retardation in deuteron photodisintegration above pi-threshold
M. Schwamb, H. Arenhoevel, P. Wilhelm +1
Photodisintegration of the deuteron above pi-threshold is studied in a coupled channel approach including N Delta- and pi d-channels with pion retardation in potentials and exchang…
On the extraction of electromagnetic properties of the Delta(1232) excitation from pion photoproduction
Th. Wilbois, P. Wilhelm, H. Arenhoevel
Several methods for the treatment of pion photoproduction in the region of the Delta(1232) resonance are discussed, in particular the effective Lagrangian approach and the speed pl…
Unitarity constraint for threshold coherent pion photoproduction on the deuteron and chiral perturbation theory
P. Wilhelm
The contribution of the two-step process gamma + d -> p + n -> pi0 + d to the imaginary part of the amplitude for coherent pion production on the deuteron is calculated exploiting…
Treatment of the current in electromagnetic two-nucleon knockout reactions
C. Giusti, F. D. Pacati, H. Arenhoevel +1
The contribution of the (1232) isobar to the electromagnetic current of the two-nucleon system and its role in (,NN) processes is investigated. The difference between the gen…
On the Gerasimov-Drell-Hearn sum rule for the deuteron
H. Arenhoevel, G. Kress, R. Schmidt +1
The Gerasimov-Drell-Hearn sum rule is evaluated for the deuteron by explicit integration up to a photon energy of 550 MeV including contributions from the photodisintegration chann…
Quasifree pion photoproduction on the deuteron in the region
R. Schmidt, H. Arenhoevel, P. Wilhelm
Photo production of pions on the deuteron is studied in the spectator nucleon model. The Born terms of the elementary production amplitude are determined in pseudovector N coupl…
Rescattering effects in coherent pion photoproduction on the deuteron in the resonance region
P. Wilhelm, H. Arenhoevel
Within a dynamical model, rescattering effects are studied in coherent pion photoproduction on the deuteron in the (1232) resonance region. The model consists of a system of cou…
Quasifree photoabsorption on neutron-proton pairs in 3He
J. A. Niskanen, P. Wilhelm, H. Arenhoevel
Three-body photodisintegration of 3He is calculated in the photon energy range 200 - 400 MeV assuming quasifree absorption on np pairs both in initial quasideuteron and singlet con…
Photon absorption on a neutron-proton pair in He
P. Wilhelm, J. A. Niskanen, H. Arenhövel
The cross section of the reaction He in the energy range 150 - 450 MeV has been calculated in a quasifree two-body model and compared with a recent kinematicall…