60 citations · 238 across the 20 of their papers we have counts for
20 papers
A practical approach to perturbative corrections to few-body observables
Sourav Mondal, Martin Schäfer, Mirko Bagnarol +3
We formulate two methods to facilitate the calculation of perturbative corrections to quantum few-body observables. Both techniques are designed for a numerical realization in comb…
Scale-(in)dependence in quantum 4-body scattering
Sourav Mondal, Rakshanda Goswami, Udit Raha +1
We investigate the multi-channel 4-body scattering system using regularized 2- and 3-body contact interactions. The analysis determines the sensitivity of bound-state energies, sca…
Calculation of Dynamical Response Functions Using a Bound-state Method
Niels R. Walet, Jagjit Singh, Johannes Kirscher +3
We investigate a method to extract response functions (dynamical polarisabilities) directly from a bound-state approach applied to calculations of perturbation-induced reactions. T…
Unitary interaction geometries in few-body systems
Lorenzo Contessi, Johannes Kirscher, Manuel Pavon Valderrama
We consider few-body systems in which only a certain subset of the particle-particle interactions is resonant. We characterize each subset by a {\it unitary graph} in which the ver…
Emergence of H resonance in contact theories
Lorenzo Contessi, Martin Schäfer, Johannes Kirscher +2
We obtain the - and -wave low-energy scattering parameters for nH elastic scattering and the position of the H resonance using the pionless effective field…
Two Particles with Zero-Range Interaction in a Magnetic Field
Johannes Kirscher, Brian C. Tiburzi
Energy levels are investigated for two charged particles possessing an attractive, momentum-independent, zero-range interaction in a uniform magnetic field. A transcendental equati…
Emergent four-body parameter in universal two-species bosonic systems
Lorenzo Contessi, Johannes Kirscher, Manuel Pavon Valderrama
The description of unitary few-boson systems is conceptually simple: only one parameter -- the three-body binding energy -- is required to predict the binding energies of clusters…
Triple-X and beyond: hadronic systems of three and more X(3872)
Lorenzo Contessi, Johannes Kirscher, Manuel Pavon Valderrama
The resonance has been conjectured to be a charm meson-antimeson two-body molecule. Meanwhile, there is no experimental evidence for larger, few-body co…
Multi-fermion systems with contact theories
Martin Schäfer, Lorenzo Contessi, Johannes Kirscher +1
We address the question of minimal requirements for the existence of quantum bound states. In particular, we demonstrate that a few-body system with zero-range momentum-independent…
Four-Body Scale in Universal Few-Boson Systems
Betzalel Bazak, Johannes Kirscher, Sebastian König +3
The role of an intrinsic four-body scale in universal few-boson systems is the subject of active debate. We study these systems within the framework of effective field theory. For…
Asymmetric regularization of the ground and excited state of the helium-4 nucleus
Johannes Kirscher, Harald W. Grießhammer
We find the threshold structure of the two- and three-nucleon systems, with the deuteron and 3H/3He as the only bound nuclei, sufficient to predict a pair of four-nucleon states: a…
Emergence of a Brunnian neutron state
Johannes Kirscher
We discuss a quantum-statistical feature of non-relativistic identical fermions whose interaction is predominantly attractive at low energies. Specifically, we consider exotic, mul…
Electromagnetic characteristics of physical and lattice nuclei
Johannes Kirscher, Ehoud Pazy, Jonathan Drachman +1
We analyze the quark-mass dependence of electromagnetic properties of two and three-nucleon states. To that end, we apply the pionless effective field theory to experimental data a…
Matching effective few-nucleon theories to QCD
Johannes Kirscher
The emergence of complex macroscopic phenomena from a small set of parameters and microscopic concepts demonstrates the power and beauty of physical theories. A theory which relate…
Spectra and Scattering of Light Lattice Nuclei from Effective Field Theory
Johannes Kirscher, Nir Barnea, Doron Gazit +2
An effective field theory is used to describe light nuclei, calculated from quantum chromodynamics on a lattice at unphysically large pion masses. The theory is calibrated at leadi…
Pionless Effective Field Theory in Few-Nucleon Systems
Johannes Kirscher
A systematic description of low-energy observables in light nuclei is presented. The effective field theory formalism without pions is extended to: i) predictions with next-to-lead…
Constraining the neutron-neutron scattering length with \eftnopi
Johannes Kirscher, Daniel R. Phillips
We compute a model-independent correlation between the difference of neutron-neutron and proton-proton scattering lengths |a(nn)-a^C(pp)| and the splitting in binding energies betw…
Zero-energy neutron-triton and proton-Helium-3 scattering with \eftnopi
Johannes Kirscher
Model-independent constraints for the neutron-triton and proton-Helium-3 scattering lengths are calculated with a leading-order interaction derived from an effective field theory w…
Universal Correlations in Pion-less EFT with the Resonating Group Model: Three, Four, and Six Nucleons
Johannes Kirscher, Harald W. Grießhammer, Deepshikha Shukla +1
A systematic connection between QCD and nuclear few- and many-body properties in the form of the Effective Field Theory "without pions" is applied to nuclei to determine i…
Universal Correlations in Pion-less EFT with the Resonating Group Model: Three and Four Nucleons
Johannes Kirscher, Harald W. Griesshammer, Deepshikha Shukla +1
The Effective Field Theory "without pions" at next-to-leading order is used to analyze universal bound state and scattering properties of the 3- and 4-nucleon system. Results of a…