16 research outputs found
Measurement of the branching fraction of the B 0 → D s + π - decay
Abstract: A branching fraction measurement of the B0→Ds+π- decay is presented using proton–proton collision data collected with the LHCb experiment, corresponding to an integrated luminosity of 5.0fb-1. The branching fraction is found to be B(B0→Ds+π-)=(19.4±1.8±1.3±1.2)×10-6, where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the B0→D-π+, Ds+→K+K-π+ and D-→K+π-π- branching fractions. This is the most precise single measurement of this quantity to date. As this decay proceeds through a single amplitude involving a b→u charged-current transition, the result provides information on non-factorisable strong interaction effects and the magnitude of the Cabibbo–Kobayashi–Maskawa matrix element Vub. Additionally, the collision energy dependence of the hadronisation-fraction ratio fs/fd is measured through B¯s0→Ds+π- and B0→D-π+ decays
Measurement of the electron reconstruction efficiency at LHCb
The single electron track-reconstruction efficiency is calibrated using a sample corresponding to 1.3 fb−1 of pp collision data recorded with the LHCb detector in 2017. This measurement exploits B+→ J/ψ(e+e−)K+ decays, where one of the electrons is fully reconstructed and paired with the kaon, while the other electron is reconstructed using only the information of the vertex detector. Despite this partial reconstruction, kinematic and geometric constraints allow the B meson mass to be reconstructed and the signal to be well separated from backgrounds. This in turn allows the electron reconstruction efficiency to be measured by matching the partial track segment found in the vertex detector to tracks found by LHCb's regular reconstruction algorithms. The agreement between data and simulation is evaluated, and corrections are derived for simulated electrons in bins of kinematics. These correction factors allow LHCb to measure branching fractions involving single electrons with a systematic uncertainty below 1%
Soft Regulations in Pharmaceutical Policy Making: An Overview of Current Approaches and their Consequences
It is a challenge to improve public health within limited resources. Pharmaceutical policy making is a greater challenge due to conflicting interests between key stakeholder groups. This paper reviews current and future strategies to help improve the quality and efficiency of care, with special emphasis on demand-side controls for pharmaceutical prescribing. A large number of different educational, organizational, financial and regulatory strategies have been applied in pharmaceutical policy making. However, the effectiveness of most strategies has not been thoroughly evaluated and there is evidence that the behaviour of healthcare professionals is difficult to influence with traditional methods. During the last decades, new modes of governing and new governing constellations have also appeared in healthcare. However, relationships between those who regulate and those regulated are often unclear. New approaches have recently been introduced, including extensive dissemination strategies for guidelines and extensive quality assessment programmes where physicians' performances are measured against agreed standards or against each other. The main components of these 'soft regulations' are standardization, monitoring and agenda setting. However, the impact of these new modes on health provision and overall costs is often unknown, and the increased focus on monitoring may result in a higher conformity and uniformity that may not always benefit all key stakeholders. Alongside this, a substantial growth of auditing associations controlling a diminishing minority of people actually performing the tasks may be costly and counter-productive. As a result, new effective strategies are urgently needed to help maintain comprehensive healthcare without prohibitively raising taxes or insurance premiums. This is especially important where countries are faced with extreme financial problems. Healthcare researchers may benefit from researching other areas of society. However, any potential strategies initiated must be adequately researched, debated and evaluated to enhance implementation. We hope this opinion paper is the first step in the process to develop and implement new demand-side initiatives building on existing 'soft regulations'.
O uso de indicadores ambientais no acompanhamento de sistemas de gerenciamento ambiental
Measurement of CP-Averaged Observables in the B-0 -> K-star 0 mu(+)mu(-) Decay
An angular analysis of the B-0 -> K-0 (-> K+pi(-))mu(+)mu(-) decay is presented using a dataset corresponding to an integrated luminosity of 4.7 fb(-1) of pp collision data collected with the LHCb experiment. The full set of CP-averaged observables are determined in bins of the invariant mass squared of the dimuon system. Contamination from decays with the K+ pi(-) system in an S-wave configuration is taken into account. The tension seen between the previous LHCb results and the standard model predictions persists with the new data. The precise value of the significance of this tension depends on the choice of theory nuisance parameters