We discuss the application of an effective theory with contact interactions to the nonrelativistic four-body system with short-range interactions. We have computed the binding energies of the 4He tetramer and the α-particle. A well-known linear correlation between threeand four-body binding energies can be understood as a result of the absence of a four-body force at leading order within this f...

We investigate the effect of uniaxial stress on InGaAs quantum dots in a charge tunable device. Using Coulomb blockade and photoluminescence, we observe that significant tuning of single particle energies (≈-0.22 meV/MPa) leads to variable tuning of exciton energies (+18 to -0.9 μeV/MPa) under tensile stress. Modest tuning of the permanent dipole, Coulomb interaction and fine-structure splittin...

Abstract. We present data on strange particle production in elementary proton-proton collisions at RHIC energies. Comparison to leading order and next-to-leading order (NLO) calculations shows that the fragmentation process is flavor dependent and that higher order corrections are needed to describe all spectra, in particular at these collision energies, which are modest compared to the Tevatro...

Recently, nuclear structure in neutron-rich nuclei has attracted much attention because of its exotic nature, such as halo and skin 1) 3). Recent advances of secondary beam techniques allow us to measure useful structure information on masses, interaction cross sections and excited states. The shell structure is one of essential issues in nuclear structure. Recently, the magic numbers in the ne...

Soft hadron production is described as a two-step process, where the interaction of the partonic constituents of the colliding hadrons leads to the production of intermediate subsystems (fireballs), which decay subsequently into hadrons. The weights of the various final states are derived from the corresponding phase-space factors modified by empirical transition elements. The results compare w...

We theoretically study the excitation spectrum of confined macroscopic optical lattices in the Mott-insulating limit. For large systems, a fast numerical method is proposed to calculate the ground state filling and excitation energies. We introduce many-particle on-site energies capturing multi-band effects and discuss tunnelling on a perturbative level using an effectively restricted Hilbert s...

The highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore...

We revisit the problem of the kink in the charge radius shift of neutron-rich even isotopes near the N=126 shell closure. We show that the ability of a Skyrme force to reproduce the isotope shift is determined by the occupation of the neutron 1i(11/2) orbital beyond N=126 and the corresponding change it causes to deeply-bound protons orbitals with a principal quantum number of 1. Given the obse...

We study nonlinear adiabatic connection paths in density-functional theory using modified electron–electron interactions that perform a long-range/short-range separation of the Coulomb interaction. These adiabatic connections allow us to define short-range exchange–correlation potentials and short-range local exchange–correlation energies per particle which we have calculated accurately for the...