One of motivations in studying the $\alpha + \alpha \rightarrow \alpha + \alpha +\gamma\,$ bremsstrahlung is to get a supplementary information on a strong part of the $\alpha-\alpha\,$ interaction [1]. We find some correlation function, in which one of the outgoing alphas is detected in coincidence with the emitted photon, depends consid-erably on the strong interaction in the entrance...
Complex-range Gaussian basis (CRGB) has been demonstrated to give a convenient representation for bound-state [1] and scattering [2] calculations. The basis functions are constructed from the conventional real-valued Gaussians with additional oscillating factors which makes them suitable for approximation of wave functions of highly excited bound states and continuum states as well. Recently,...
Treating deuteron breakup in (d,p) reaction requires solving three-body Schrodinger equation with nucleon optical potentials. According to a general theory of optical potentials they should be nonlocal. We present two approximate methods to account for this nonlocality within the Continuum-Discretized Coupled Channel (CDCC) method:
(1) we derive a leading-order local-equivalent CDCC model...
The kaonic cluster $NN{\bar K}(s_{NN}=0)$ is modeled based on the configuration space Faddeev equations. The $N{\bar K}$ interaction is given by isospin-dependent potentials having significant difference between singlet and triplet components. We show that the relation $\left\vert E_{3}(V_{AA}=0)\right\vert~<~2\left\vert E_{2}\right\vert$ is satisfied, where $E_{2}$ is the binding energy of...
The best strategy to precisely determine the energy difference between two adjacent energy levels is to perform an interferometric measurement. If the signal-to-noise ratio (SNR) is not favorable, either due to large unavoidable noise or a naturally small signal, but the signal is many oscillations long, the standard analysis takes advantage of a fast Fourier transform (FFT). What if the...
A one-dimensional system of bosons interacting with contact and single-Gaussian forces is studied with an expansion in hyperspherical harmonics. The hyperradial potentials are calculated using the link between the hyperspherical harmonics with single-particle harmonic oscillator basis and the coupled hyperradial equations are solved with the Lagrange-mesh method. Extensions of this method are...
Since the origin of nuclear physics, cluster structures have been observed in the excited states of many light nuclei.${}^\text{1}$ It is noted that $\alpha$ particles are strong cluster candidates due to their significant binding energy and energy of their first excited state. Evidence for this clustering lies within the energy levels of the compound nucleus formed in scattering reactions,...
Superheavy elements (SHE) have an atomic number Z ≥ 104, and their existence was predicted almost 50 years ago due to quantum shell effects that influence their stability and decay [1]. SHE production is very challenging (due to very small cross sections in the range of a few picobarns or less), with complete fusion of heavy ions being one of the most successful ways of producing SHEs. The...
The CREMA collaboration plans to measure the Lamb shift in muonic Lithium atoms,
with the goal to extract the charge radius and confront it to electron scattering data.
For this experiment to be successful, theoretical information on the nuclear structure
corrections to the Lamb shift are needed.
Recently, few-body methods were used to tackle this problem and the most precise
estimate of...
We have extended our previous applications of the method of unitary clothing transformations (UCTs) in mesodynamics [1] to quantum electrodynamics (QED) [2,3]. Starting from the primary canonical interaction between electromagnetic and electron-positron fields, the QED Hamiltonian has been expressed through a new family of the Hermitean and energy independent interaction operators built up in...
The 7H isotope is the Golden Fleece to be searched by the RIB holders. Until the present moment only upper limits of its lifetime and ground state energy were estimated. Such unbound complicated five-body nuclear system, which has extremely large mass-to-charge ratio, lies far beyond the drip-line and has not been detected yet.
An experimental search for the 7H resonance was performed with the...
Inspired by the Faddeev-Merkuriev approach [1] we have modified the four-body Faddeev-Yakubovsky [2] equations, writing them in a form suitable to solve the four-body Coulomb problem. The newly developed formalism has been applied to study bound and some resonant states in (Ps)$_2$ and $\overline{H}$-Ps compounds. The first successful attempt to describe low energy Ps-Ps and...
We investigated three-nucleon force (3NF) effects in the Final State Interaction (FSI) configuration of the $d (n,nn) p$ breakup reaction. Solutions of the 3N Faddeev equations $[1]$ with the CDBonn nucleon-nucleon potential $[2]$ and the Tucson-Melbourne 3NF $[3]$ give access not only to the elastic scattering observables but also to the three-body breakup ones. In this contribution we focus...
We use nuclear time-dependent Hartree-Fock (TDHF) to simulate the reaction of three alpha particles at low energy by first fusing two alpha to from $^8$Be* followed by a third alpha impinging during the lifetime of the beryllium resonance. Depending on the energies and impact parameters of the reacting nuclei different outcomes are obtained with some fusion events showing short-lived alpha...
The first evidence for universality in three-body systems was the discovery by Vitally Efimov of the Efimov effect [1], a remarkable feature of the three-body spectrum for identical bosons with resonant short-range interactions. Nowadays it has been realized that the striking features of the Efimov effect are not restricted to three-body systems, but propagate by increasing the number of...
