Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

Pension Design and Risk Sharing: Mixed Solutions Between Defined Benefit and Defined Contribution for Public Pension Schemes

In classical pension design, there are essentially two kinds of pension schemes: Defined Benefit (DB) and Defined Contribution (DC) plans. Each scheme corresponds to a different philosophy of spreading risk between the stakeholders: in a DB, the main risks are taken by the organizer of the plan, while in a DC, the affiliates must bear all the risks. Especially when applied to social security pension systems, this traditional view can in both cases lead to unfair intergenerational equilibrium. The purpose of this chapter is to present alternative architectures based on a mix between DB and DC in order to achieve both financial sustainability and social adequacy. An example of this approach is the so-called Musgrave rule, but other risk-sharing approaches will be developed in a pay-as-you-go philosophy. These principles will be illustrated by the Belgian proposition of reform of the first pillar, based on a points system with a simultaneous automatic adaptation mechanism of the retirement age, the contribution rate, the replacement rate, and the indexation rate

The Actuarial Balance Sheet for Pay-As-You-Go Finance: Solvency Indicators for Spain and Sweden

This paper provides the first estimate of the actuarial balance of the Spanish contributory pension system for the old-age contingency, based on official data. The main accounting entries are developed from the principles of double-entry bookkeeping. The novel entry in the balance sheet, entitled the 'contribution asset' or 'hidden asset', is at the centre of the theoretical discussion. A comparison between the official balance sheet for the Swedish notional account system and our balance sheet for the Spanish contributory pension system is also provided. The main finding is that the Spanish pension system has an insolvency rate of 31.4 per cent. The policy implication is that unless current legislation is reformed, Spanish taxpayers (the plan sponsor) should count on making transfers to the pension system with a present discounted value of 31.4 per cent of current liabilities. Moreover, a comparison of the consecutive balance sheets for 2001-06 shows that the degree of insolvency is growing over time, even though the cash-flow outcome has improved over the same period. Taking steps to reverse this trend and restore solvency is in Spanish taxpayers' interest, and possibly also in the interest of those in the European Union who recognise that there is a chance that they may have to support the Spanish budget in the future. Copyright (c) 2008 The Authors.