Related papers: An Effective Theory for the Four-Body System
The Bethe-Salpeter equation for three bosons with zero-range interaction is solved for the first time. For comparison the light-front equation is also solved. The input is the two-body scattering length and the outputs are the three-body…
For a system of fermions with a three-body contact interaction the second-order contributions to the energy per particle $\bar E(k_f)$ are calculated exactly. The three-particle scattering amplitude in the medium is derived in closed…
The appropriate power counting for the effective field theory of NN interactions is reviewed. It is more subtle than in most effective field theories since in the limit that the S-wave NN scattering lengths go to infinity it is governed by…
A study of the $\eta$-3N interaction in the energy region near the $\eta$-^3H elastic scattering threshold is presented. The calculational scheme is based on the four-body scattering formalism. A manageable form of the integral equations is…
We present a mathematically rigorous method suitable for solving three-body bound state and scattering problems when the inter-particle interaction is of a hard-core nature. The proposed method is a variant of the Boundary Condition Model…
Resonances are of particular importance to the scattering of composite particles in quantum mechanics. We build an effective field theory for two-body scattering which includes a low-energy $S$-wave resonance. Our starting point is the most…
We examine in detail two alternative descriptions of a system of $\alpha$ particles interacting via local interactions of different character, highlighting the fact that a faithful microscopic description of such systems demands a…
Effective Field Theory (EFT) provides a powerful framework that exploits a separation of scales in physical systems to perform systematically improvable, model-independent calculations. Particularly interesting are few-body systems with…
The Faddeev-Yakubovsky equations for the alpha-particle are solved. Accurate results are obtained for several modern NN interaction models, which include charge-symmetry breaking effects in the NN force, nucleon mass dependences as well as…
This work reviews recent advances in the analytical treatment of the continuum spectrum of correlated few-body non-relativistic Coulomb systems. The exactly solvable two-body problem serves as an introduction to the non-separable…
We report various many-body theoretical approaches to the nonlinear decay rate and energy loss of charged particles moving in an interacting free electron gas. These include perturbative formulations of the scattering matrix, the…
We report recent advances on the study of universal weakly bound four-boson states from the solutions of the Faddeev-Yakubovsky equations with zero-range two-body interactions. In particular, we present the correlation between the energies…
The four-neutron system is studied using exact continuum equations for transition operators and solving them in the momentum-space framework. A resonant behavior is found for strongly enhanced interaction but not a the physical strength,…
An effective field theory for the three-body system with large scattering length is applied to three-body recombination to a weakly-bound s-wave state in a Bose gas. Our model independent analysis demonstrates that the three-body…
An effective field theory for the three-body system with large scattering length a is applied to three-body recombination into deep bound states in a Bose gas. The recombination constant \alpha is calculated to first order in the…
A large two-body scattering length leads to universal behavior in few-body systems. In particular, the three-body system displays interesting features such as exact discrete scale invariance in the bound state spectrum in the limit of…
We perform a renormalization group analysis of the non-relativistic four-boson problem by means of a simple model with pointlike three- and four-body interactions. We investigate in particular the unitarity point where the scattering length…
A brief review of relativistic effects in few-body systems, of theoretical approaches, recent developments and applications is given. Manifestations of relativistic effects in the binding energies, in the electromagnetic form factors and in…
I discuss effective field theories for heavy bound systems, particularly bound systems involving two heavy quarks. The emphasis is on the relevant concepts and on interesting physical applications and results.
A two-component four-fermion system with equal masses, interspecies s-wave scattering length a and vanishing intraspecies interactions under external spherically symmetric harmonic confinement is considered. Using a correlated Gaussian…