High-spin intruder states in the fp shell nuclei and isoscalar proton-neutron correlations

We perform a systematic shell-model and mean-field study of fully-aligned, high-spin f_{7/2}^{n} seniority isomers and d_{3/2}^{-1} f_{7/2}^{n+1} intruder states in the A~44 nuclei from the lower-fp shell. The shell-model calculations are performed in the full sdfp configuration space allowing 1p-1h cross-shell excitations. The self-consistent mean-field calculations are based on the Hartree-Fock approach with the Skyrme energy density functional that reproduces empirical Landau parameters. While there is a nice agreement between experimental and theoretical relative energies of fully-aligned states in N>Z nuclei, this is no longer the case for the N=Z systems. The remaining deviation from the data is attributed to the isoscalar proton-neutron correlations. It is also demonstrated that the Coulomb corrections at high spins noticeably depend on the choice of the energy density functional.Comment: 4 pages. submitted to Phys. Rev. Let

Badger: Complexity Analysis with Fuzzing and Symbolic Execution

Hybrid testing approaches that involve fuzz testing and symbolic execution have shown promising results in achieving high code coverage, uncovering subtle errors and vulnerabilities in a variety of software applications. In this paper we describe Badger - a new hybrid approach for complexity analysis, with the goal of discovering vulnerabilities which occur when the worst-case time or space complexity of an application is significantly higher than the average case. Badger uses fuzz testing to generate a diverse set of inputs that aim to increase not only coverage but also a resource-related cost associated with each path. Since fuzzing may fail to execute deep program paths due to its limited knowledge about the conditions that influence these paths, we complement the analysis with a symbolic execution, which is also customized to search for paths that increase the resource-related cost. Symbolic execution is particularly good at generating inputs that satisfy various program conditions but by itself suffers from path explosion. Therefore, Badger uses fuzzing and symbolic execution in tandem, to leverage their benefits and overcome their weaknesses. We implemented our approach for the analysis of Java programs, based on Kelinci and Symbolic PathFinder. We evaluated Badger on Java applications, showing that our approach is significantly faster in generating worst-case executions compared to fuzzing or symbolic execution on their own

An absorption spectrum amplifier for determining gas composition

Compositions of gas samples are frequently studied by laser absorption spectroscopy. Sensitivity is improved by two orders of magnitude when absorption cell is placed inside an organic-dye laser cavity

Spin-orbit and tensor mean-field effects on spin-orbit splitting including self-consistent core polarizations

A new strategy of fitting the coupling constants of the nuclear energy density functional is proposed, which shifts attention from ground-state bulk to single-particle properties. The latter are analyzed in terms of the bare single-particle energies and mass, shape, and spin core-polarization effects. Fit of the isoscalar spin-orbit and both isoscalar and isovector tensor coupling constants directly to the f5/2-f7/2 spin-orbit splittings in 40Ca, 56Ni, and 48Ca is proposed as a practical realization of this new programme. It is shown that this fit requires drastic changes in the isoscalar spin-orbit strength and the tensor coupling constants as compared to the commonly accepted values but it considerably and systematically improves basic single-particle properties including spin-orbit splittings and magic-gap energies. Impact of these changes on nuclear binding energies is also discussed.Comment: 15 pages, 7 figures, submitted to Physical Review

Mixed Messages: Measuring Conformance and Non-Interference in TypeScript (Artifact)

In the paper Mixed Messages: Measuring Conformance and Non-Interference in TypeScript we present our experiences of evaluating gradual typing using our tool TypeScript TPD. The tool, based on the polymorphic blame calculus, monitors JavaScript libraries and TypeScript clients against the corresponding TypeScript definition. Our experiments yield two conclusions. First, TypeScript definitions are prone to error. Second, there are serious technical concerns with the use of the JavaScript proxy mechanism for enforcing contracts. This artifact includes all the libraries we tested, their definition files, and the source code of our tool. From this, all libraries can be wrapped and tested to reproduce the log data that formed our conclusion. All conformance errors and examples of interference are documented, and can be verified against the generated logs

Finite size scaling analysis of intermittency moments in the two dimensional Ising model

Finite size scaling is shown to work very well for the block variables used in intermittency studies on a 2-d Ising lattice. The intermittency exponents so derived exhibit the expected relations to the magnetic critical exponent of the model. Email contact: [email protected]: Saclay-T93/063 Email: [email protected]

Isgur-Wise Functions from the Mit Bag Model

The Isgur-Wise functions for the ground state to ground state semileptonic decays involving $b \rightarrow c$ transitions are calculated from the (modified) MIT bag model. It is checked that the results for the decays $\overline{B} \rightarrow D l \overline\nu$ and $\overline{B} \rightarrow D^* l \overline\nu$ agree well with experiment. Predictions for the decays $\Lambda_b \rightarrow \Lambda_c l \overline\nu$, $\overline{B}_s \rightarrow D_s l \overline\nu$ and $\overline{B}_s \rightarrow D^*_s l \overline\nu$ are given and discussed.Comment: 12 pages (3 figures available upon request), LaTeX, TPJU - 9/9