16408480
Effective Kaon energy from a novel chiral SU(3) model
Abstract A new chiral SU(3) Lagrangian is proposed to describe the properties of kaons and anti-kaons in the nuclear medium, The saturation properties of nuclear matter are reproduced as well as the results of the Dirac-Briickner theory, After introducing the coupling between the omega meson and the kaon, our results for effective kaon and anti-kaon energy are quite similar as calculated in the one-boson-exchange model.
13153867
Mass measurements of very neutron-deficient Mo and Tc isotopes and their impact on rp process nucleosynthesis.
The masses of ten proton-rich nuclides, including the N=Z+1 nuclides ⁸⁵Mo and ⁸⁷Tc, were measured with the Penning trap mass spectrometer SHIPTRAP. Compared to the Atomic Mass Evaluation 2003 a systematic shift of the mass surface by up to 1.6 MeV is observed causing significant abundance changes of the ashes of astrophysical x-ray bursts. Surprisingly low α separation energies for neutron-deficient Mo and Tc are found, making the formation of a ZrNb cycle in the rp process possible. Such a cycle would impose an upper temperature limit for the synthesis of elements beyond Nb in the rp process.
121183473
Observation of rotating nuclear molecules and determination of their lifetimes
Long-living rotating nuclear molecules (or “dinuclear systems”) have been observed at the velocity filter SHIP at GSI in reactions of 64Ni + 207Pb at Coulomb barrier energies. The rotation was directly revealed by the velocity spectra of deep inelastic target-like transfer products which are formed during the lifetime of the nuclear molecule and emitted after its breakup. The corresponding rotation angles were about 180 degree pointing to long nuclear interaction times or lifetimes of the system, respectively. We deduced the lifetimes from the lines in the velocity spectra originating from two different rotation angles. Further, the unambiguous correlation of a certain transfer product with its individual velocity spectrum allowed us to study the lifetimes as a function of the number of transferred protons.
120695709
Strong influence of the entrance channel on the formation of compound nuclei Th216,222* and their evaporation residues
The dynamical effects of the entrance channel on the formation of the evaporation residues are studied by analyzing the $^{40}\mathrm{Ar}+^{176}\mathrm{Hf}$, $^{86}\mathrm{Kr}+^{130,136}\mathrm{Xe}$, $^{124}\mathrm{Sn}+^{92}\mathrm{Zr}$, and $^{48}\mathrm{Ca}+^{174}\mathrm{Yb}$ reactions leading to the $^{216}\mathrm{Th}{}^{*}$ and $^{222}\mathrm{Th}{}^{*}$ compound nuclei. We find that the difference between the evaporation residue cross sections for the reactions leading to the same compound nucleus is caused by the different angular momentum distributions of the partial fusion cross sections ${\ensuremath{\sigma}}_{\mathrm{fus}}^{\ensuremath{\ell}}({E}_{c.m.})$. The strong dependence of the fusion angular momentum distribution on the mass (charge) asymmetry and shell structure of reactants is demonstrated. The effect of the $A/Z$ ratio for the $^{86}\mathrm{Kr}+^{130,136}\mathrm{Xe}$ reactions is discussed. The dynamical conditions of capture affect the competition between complete fusion and quasifission and, consequently, the shape of the angular momentum distribution of the compound nucleus. By this way the peculiarities of the entrance channel also affect the fission-evaporation competition of the excited intermediate nuclei along the deexcitation cascade of the compound nucleus and, consequently, the evaporation residue formation.
119438146
The discovery of the heaviest elements
123051492
The velocity filter ship, a separator of unslowed heavy ion fusion products
The velocity filter SHIP installed at the UNILAC (GSI Darmstadt) is described. It is used for the investigation of neutron deficient nuclei generated by heavy ion induced fusion. The two stage filter separates unretarded reaction products emerging from a thin target with high efficiency and low background of primary beam particles. For reaction products covering an angular range of 3° in horizontal and vertical directions and a velocity range of 10% the transmission is between 30% and 60%. The separation time is of the order of 10−6s. High suppression of primary particles by factors of 107-1011 permits the investigation of reaction products in the direction of the primary beam. α-active reaction products have been implanted into a surface barrier detector and identified by their decay. 
 
A description of the ion optical principles, technical details and the performance of SHIP is given.
119090594
Lorentz-invariant ensembles of vector backgrounds
We consider gauge field theories in the presence of ensembles of vector backgrounds. While Lorentz invariance is explicitly broken in the presence of any single background, here, the Lorentz invariance of the theory is restored by averaging over a Lorentz-invariant ensemble of backgrounds, i.e., a set of background vectors that is mapped onto itself under Lorentz transformations. This framework is used to study the effects of a non-trivial but Lorentz-invariant vacuum structure or mass dimension two vector condensates by identifying the background with a shift of the gauge field. Up to now, the ensembles used in the literature comprise configurations corresponding to non-zero field tensors together with such with vanishing field strength. We find that even when constraining the ensembles to pure gauge configurations, the usual high-energy degrees of freedom are removed from the spectrum of asymptotic states in the presence of said backgrounds in Euclidean and in Minkowski space. We establish this result not only for the propagators to all orders in the background and otherwise at tree level but for the full propagator.
119225428
Cascading gravity and degravitation
We construct a cascading brane model of gravity in which the behavior of the gravitational force law interpolates from (n+4)-dimensional to (n+3)-dimensional all the way down to 4-dimensional from longer to shorter length scales. We show that, at the linearized level, this model exhibits the features necessary for degravitation of the cosmological constant. The model is shown to be ghost free with the addition of suitable brane kinetic operators, and we demonstrate this using a number of independent procedures. Consequently this is a consistent infrared (IR) modification of gravity, providing a promising framework for a dynamical, degravitating solution of the cosmological constant problem.
119466901
Small scale WIMP physics
The dark matter distribution on small scales may depend on the the properties of the first generation of dark matter halos to form, which is in turn determined by the microphysics of the dark matter particles. We overview the microphysics of WIMPs and our calculations of the collisional damping and free streaming scales. We then plot the resulting density perturbation power spectrum and red‐shift at which typical halos form, taking into account the effect of uncertainties in the WIMP properties (mass and interaction channel) and the primordial power spectrum. Finally we review recent developments regarding the properties and fate of the first WIMPy halos.
118359212
Generic inference of inflation models by non-Gaussianity and primordial power spectrum reconstruction
We present a generic inference method for inflation models from observational data by the usage of higher-order statistics of the curvature perturbation on uniform density hypersurfaces. This method is based on the calculation of the posterior for the primordial non-Gaussianity parameters fNL and gNL, which in general depend on specific parameters of inflation and reheating models, and enables to discriminate among the still viable inflation models. To keep analyticity as far as possible to dispense with numerically expensive sampling techniques a saddle-point approximation is introduced, whose precision is validated for a numerical toy example. The mathematical formulation is done in a generic way so that the approach remains applicable to cosmic microwave background data as well as to large scale structure data. Additionally, we review a few currently interesting inflation models and present numerical toy examples thereof in two and three dimensions to demonstrate the efficiency of the higher-order statistics method. A second quantity of interest is the primordial power spectrum. Here, we present two Bayesian methods to infer it from observational data, the so called critical filter and an extension thereof with smoothness prior, both allowing for a non-parametric spectrum reconstruction. These methods are able to reconstruct the spectra of the observed perturbations and the primordial ones of curvature perturbation even in case of non-Gaussianity and partial sky coverage. We argue that observables like T- and B-modes permit to measure both spectra. This also allows to infer the level of non-Gaussianity generated since inflation.
119207510
Consistency of relevant cosmological deformations on all scales
Using cosmological perturbation theory we show that the most relevant deformation of gravity is consistent at the linear level. In particular, we prove the absence of unitarity violating negative norm states in the weak coupling regime from sub- to super-Hubble scales. This demonstrates that the recently proposed classical self-protection mechanism of deformed gravity extends to the entire kinematical domain.