Precision Measurement of 11Li moments: Influence of Halo Neutrons on the 9Li Core

The electric quadrupole moment and the magnetic moment of the 11Li halo nucleus have been measured with more than an order of magnitude higher precision than before, |Q| = 33.3(5)mb and mu=3.6712(3)mu_N, revealing a 8.8(1.5)% increase of the quadrupole moment relative to that of 9Li. This result is compared to various models that aim at describing the halo properties. In the shell model an increased quadrupole moment points to a significant occupation of the 1d orbits, whereas in a simple halo picture this can be explained by relating the quadrupole moments of the proton distribution to the charge radii. Advanced models so far fail to reproduce simultaneously the trends observed in the radii and quadrupole moments of the lithium isotopes.Comment: 4 pages, 4 figures, 1 tabl

Spectroscopic distinction between the normal state pseudogap and the superconducting gap of cuprate high T_{c} superconductors

We report on broad-band infrared ellipsometry measurements of the c-axis conductivity of underdoped RBa_{2}Cu_{3}O_{7-d} (R=Y, Nd, and La) single crystals. Our data provide a detailed account of the spectral weight (SW) redistributions due to the normal state pseudogap (PG) and the superconducting (SC) gap. They show that these phenomena involve different energy scales, exhibit distinct doping dependencies and thus are likely of different origin. In particular, the SW redistribution in the PG state closely resembles the one of a conventional charge- or spin density wave (CDW or SDW) system.Comment: 4 pages, 4 figure

Manifestation of pseudogap in ab-plane optical characteristics

A model in which a gap forms in the renormalized electronic density of state (DOS) with missing states recovered just above the pseudogap $\Delta_{pg}$, is able to give a robust description of the striking, triangular like, peak seen in the real part of the optical self-energy of underdoped cuprates. We use this model to explore the effect of the pseudogap on the real part of the optical conductivity and on the partial sum rule associated with it. An important result is that the optical spectral weight redistributes over a much larger frequency window than it does in the DOS.Comment: 12 pages, 3 figures. Submitted to Journal of Physics: Condensed Matte

Synthesizing and tuning chemical reaction networks with specified behaviours

We consider how to generate chemical reaction networks (CRNs) from functional specifications. We propose a two-stage approach that combines synthesis by satisfiability modulo theories and Markov chain Monte Carlo based optimisation. First, we identify candidate CRNs that have the possibility to produce correct computations for a given finite set of inputs. We then optimise the reaction rates of each CRN using a combination of stochastic search techniques applied to the chemical master equation, simultaneously improving the of correct behaviour and ruling out spurious solutions. In addition, we use techniques from continuous time Markov chain theory to study the expected termination time for each CRN. We illustrate our approach by identifying CRNs for majority decision-making and division computation, which includes the identification of both known and unknown networks.Comment: 17 pages, 6 figures, appeared the proceedings of the 21st conference on DNA Computing and Molecular Programming, 201

Production of new neutron-rich isotopes of heavy elements in fragmentation reactions of 238^{238}U projectiles at 1 A GeV

The production of heavy neutron-rich nuclei has been investigated using cold fragmentation reactions of $^{238}$U projectiles at relativistic energies. The experiment performed at the high-resolving-power magnetic spectrometer FRS at GSI allowed to identify 45 new heavy neutron-rich nuclei: $^{205}$Pt, $^{207-210}$Au, $^{211-216}$Hg, $^{213-217}$Tl, $^{215-220}$Pb, $^{219-224}$Bi, $^{221-227}$Po, $^{224-229}$At, $^{229-231}$Rn and $^{233}$Fr. The production cross sections of these nuclei were also determined and used to benchmark reaction codes that predict the production of nuclei far from stability.Comment: 5 pages, 2 figure

Ground-State Electromagnetic Moments of Calcium Isotopes

High-resolution bunched-beam collinear laser spectroscopy was used to measure the optical hyperfine spectra of the $^{43-51}$Ca isotopes. The ground state magnetic moments of $^{49,51}$Ca and quadrupole moments of $^{47,49,51}$Ca were measured for the first time, and the $^{51}$Ca ground state spin $I=3/2$ was determined in a model-independent way. Our results provide a critical test of modern nuclear theories based on shell-model calculations using phenomenological as well as microscopic interactions. The results for the neutron-rich isotopes are in excellent agreement with predictions using interactions derived from chiral effective field theory including three-nucleon forces, while lighter isotopes illustrate the presence of particle-hole excitations of the $^{40}$Ca core in their ground state.Comment: Accepted as a Rapid Communication in Physical Review

Spins, Electromagnetic Moments, and Isomers of 107-129Cd

The neutron-rich isotopes of cadmium up to the N=82 shell closure have been investigated by high-resolution laser spectroscopy. Deep-UV excitation at 214.5 nm and radioactive-beam bunching provided the required experimental sensitivity. Long-lived isomers are observed in 127Cd and 129Cd for the first time. One essential feature of the spherical shell model is unambiguously confirmed by a linear increase of the 11/2- quadrupole moments. Remarkably, this mechanism is found to act well beyond the h11/2 shell

Co-existing structures in 105Ru

New positive-parity states, having a band-like structure, were observed in 105Ru. The nucleus was produced in induced fission reaction and the prompt gamma-rays, emitted from the fragments, were detected by the EUROBALL III multi-detector array. The partial scheme of excited 105Ru levels is analyzed within the Triaxial-Rotor-plus-Particle approach