Ion tracking simulations for the WITCH experiment

The WITCH experiment (standing for Weak Interation Trap for CHarged particles) is dedicated to high-precision measurements of fundamental properties of electroweak interaction. Its first goal is to indirectly determine the electron-neutrino correlation coefficient in $\beta$ decay by measuring the energy spectrum of the recoiling nuclei. For this, a set-up consisting of two Penning traps, a retardation spectrometer and an MCP (Microchannel Plate) detector was designed and coupled to REXTRAP at ISOLDE/CERN

Strong-interaction Isospin-symmetry Breaking Within the Density Functional Theory

The conventional Skyrme interaction is generalized by adding zerorange charge-symmetry-breaking and charge-independence-breaking terms, and the corresponding energy density functional is derived. It is shown that the extended model accounts for experimental values of mirror and triplet displacement energies (MDEs and TDEs) in sd-shell isospin triplets with, on average, ∼ 100 keV precision using only two additional adjustable coupling constants. Moreover, the model is able to reproduce, for the first time, the A = 4n versus A = 4n + 2 staggering of the TDEs.peerReviewe