Multi-strange baryon production in pp, p-Pb and Pb-Pb collisions measured with ALICE at the LHC

Multi-strange baryons are of particular interest in the understanding of particle production mechanisms, as their high strangeness content makes them susceptible to changes in the hadrochemistry of the colliding systems. In ALICE, these hyperons are reconstructed via the detection of their weak decay products, which are identified through their measured ionisation losses and momenta in the Time Projection Chamber. The production rates of charged $\Xi$ and $\Omega$ baryons in proton-proton (pp), proton-lead (p-Pb) and lead-lead (Pb-Pb) collisions are reported as a function of $p_{\mathrm{T}}$. A direct comparison in the hyperon-to-pion ratios between the three collision systems is made as a function of event charged-particle multiplicity. The recently measured production rates in p-Pb interactions reveal an enhancement with increasing event multiplicity, consistent with a hierarchy dependent on the strangeness content of the hyperons. These results are discussed in the context of chemical equilibrium predictions, taking into account the extracted temperature parameter from a thermal model fit to the hadron yields in Pb-Pb data

The current account as a dynamic portfolio choice problem

The current account can be understood as the outcome of investment decisions made by domestic and foreign investors. These decisions can be decomposed into a portfolio rebalancing and a portfolio growth component. This paper provides empirical evidence of the importance of portfolio rebalancing for the dynamics of the current account. The authors evaluate the predictions of a partial-equilibrium model of the current account with dynamic portfolio choices, in which portfolio rebalancing is driven by changes in investment opportunities. Using data for the United States and Japan, the authors find evidence supporting innovations in investment opportunities as an important mechanism to explain international capital flows.Debt Markets,Emerging Markets,Economic Theory&Research,Currencies and Exchange Rates,Investment and Investment Climate

Fast and High-Fidelity Entangling Gate through Parametrically Modulated Longitudinal Coupling

We investigate an approach to universal quantum computation based on the modulation of longitudinal qubit-oscillator coupling. We show how to realize a controlled-phase gate by simultaneously modulating the longitudinal coupling of two qubits to a common oscillator mode. In contrast to the more familiar transversal qubit-oscillator coupling, the magnitude of the effective qubit-qubit interaction does not rely on a small perturbative parameter. As a result, this effective interaction strength can be made large, leading to short gate times and high gate fidelities. We moreover show how the gate infidelity can be exponentially suppressed with squeezing and how the entangling gate can be generalized to qubits coupled to separate oscillators. Our proposal can be realized in multiple physical platforms for quantum computing, including superconducting and spin qubits.Comment: 5 pages, 3 figures, Supplemental Materia

Performance evaluation of the Mojette erasure code for fault-tolerant distributed hot data storage

Packet erasure codes are today a real alternative to replication in fault tolerant distributed storage systems. In this paper, we propose the Mojette erasure code based on the Mojette transform, a formerly tomographic tool. The performance of coding and decoding are compared to the Reed-Solomon code implementations of the two open-source reference libraries namely ISA-L and Jerasure 2.0. Results clearly show better performances for our discrete geometric code compared to the classical algebraic approaches. A gain factor up to $2$ is measured in comparison with the ISA-L Intel . Those very good performances allow to deploy Mojette erasure code for hot data distributed storage and I/O intensive applications.Comment: 5 page

Frequency stability of a wavelength meter and applications to laser frequency stabilization

Interferometric wavelength meters have attained frequency resolutions down to the MHz range. In particular, Fizeau interferometers, which have no moving parts, are becoming a popular tool for laser characterization and stabilization. In this article, we characterize such a wavelength meter using an ultra-stable laser in terms of relative frequency instability $\sigma_y(\tau)$ and demonstrate that it can achieve a short-term instability $\sigma_y(1 s) \approx 2{\times}10^{-10}$ and a frequency drift of order $10$ MHz/day. We use this apparatus to demonstrate frequency control of a near-infrared laser, where a frequency instability below $3{\times}10^{-10}$ from 1 s to 2000 s is achieved. Such performance is for example adequate for ions trapping and atoms cooling experiments.Comment: 5 pages, 4 figure