With the expected discontinuation of the LIBOR publication, a robust fallback for related financial instruments is paramount. In recent months, several consultations have taken place on the subject. ...The results of the first ISDA consultation have been published in November 2018 and a new one just finished at the time of writing. This note describes issues associated to the proposed approaches and potential alternative approaches in the framework and the context of quantitative finance. It evidences a clear lack of details and lack of measurability of the proposed approaches which would not be achievable in practice. It also describes the potential of asymmetrical information between market participants coming from the adjustment spread computation. In the opinion of this author, a fundamental revision of the fallback's foundations is required.
Extensive efforts are devoted to the electrification of aircraft by introducing higher electrical power levels. Accordingly, the electrical components, wires and interconnects, are being increasingly ...applied on-board, and their insulations are inexorably facing heightened challenges of higher electric stresses, more stringent installation conditions, and a wide variety of environmental constraints. It could lead to multiple insulation aging patterns, entailing various failure modes. Thus, the insulation has been seen as a pivotal element in every on-board electrical component and equipment, since its current performances could govern the on-board voltage rating. Here, we first drew up the constraints facing such insulations before specifying the criteria governing their selection. Then, we reviewed in detail the high-performance insulations used, and those that are intended to be potentially used, for electrically isolating the aeronautical components employed for power transmission. The aim is to elucidate the limits of the current insulations in respect of the aforementioned constraints, and to identify the merits of the candidate ones. This review does not only provide a broad assortment of key knowledge on insulating materials, much sought after by component designers, manufacturers and engineering researchers, but also reveals for the scientific polymer community the issue of electrically insulating aeronautical components.
Production cross-sections of prompt charm mesons are measured with the first data from $pp$ collisions at the LHC at a centre-of-mass energy of $13\,\mathrm{TeV}$. The data sample corresponds to an ...integrated luminosity of $4.98 \pm 0.19\,\mathrm{pb}^{-1}$ collected by the LHCb experiment. The production cross-sections of $D^{0}$, $D^{+}$, $D_{s}^{+}$, and $D^{*+}$ mesons are measured in bins of charm meson transverse momentum, $p_{\mathrm{T}}$, and rapidity, $y$, and cover the range $0 < p_{\mathrm{T}} < 15\,\mathrm{GeV}/c$ and $2.0 < y < 4.5$. The ratios of the integrated cross-sections between charm mesons agree with previously measured fragmentation fractions. The inclusive $c\overline{c}$ cross-section within the range of $0 < p_{\mathrm{T}} < 8\,\mathrm{GeV}/c$ is found to be \ \sigma(pp \to c\overline{c}X) = 2940 \pm 3 \pm 180 \pm 160\,\mu\mathrm{b} \ where the uncertainties are due to statistical, systematic and fragmentation fraction uncertainties, respectively.
The $B_s^0 \rightarrow J/\psi \phi \phi$ decay is observed in $pp$ collision data corresponding to an integrated luminosity of 3 fb$^{-1}$ recorded by the LHCb detector at centre-of-mass energies of ...7 TeV and 8 TeV. This is the first observation of this decay channel, with a statistical significance of 15 standard deviations. The mass of the $B_s^0$ meson is measured to be $5367.08\,\pm \,0.38\,\pm\, 0.15$ MeV/c$^2$. The branching fraction ratio $\mathcal{B}(B_s^0 \rightarrow J/\psi \phi \phi)/\mathcal{B}(B_s^0 \rightarrow J/\psi \phi)$ is measured to be $0.0115\,\pm\, 0.0012\, ^{+0.0005}_{-0.0009}$. In both cases, the first uncertainty is statistical and the second is systematic. No evidence for non-resonant $B_s^0 \rightarrow J/\psi \phi K^+ K^-$ or $B_s^0 \rightarrow J/\psi K^+ K^- K^+ K^-$ decays is found.
An angular analysis of the $B^{0}\rightarrow K^{*0}(\rightarrow K^{+}\pi^{-})\mu^{+}\mu^{-}$ decay is presented. The dataset corresponds to an integrated luminosity of $3.0\,{\mbox{fb}^{-1}}$ of $pp$ ...collision data collected at the LHCb experiment. The complete angular information from the decay is used to determine $C\!P$-averaged observables and $C\!P$ asymmetries, taking account of possible contamination from decays with the $K^{+}\pi^{-}$ system in an S-wave configuration. The angular observables and their correlations are reported in bins of $q^2$, the invariant mass squared of the dimuon system. The observables are determined both from an unbinned maximum likelihood fit and by using the principal moments of the angular distribution. In addition, by fitting for $q^2$-dependent decay amplitudes in the region $1.1<q^{2}<6.0\mathrm{\,Ge\kern -0.1em V}^{2}/c^{4}$, the zero-crossing points of several angular observables are computed. A global fit is performed to the complete set of $C\!P$-averaged observables obtained from the maximum likelihood fit. This fit indicates differences with predictions based on the Standard Model at the level of 3.4 standard deviations. These differences could be explained by contributions from physics beyond the Standard Model, or by an unexpectedly large hadronic effect that is not accounted for in the Standard Model predictions.
A search for B0(s)→K0SK∗(892)0 decays is performed using pp collision data, corresponding to an integrated luminosity of 1.0 fb−1, collected with the LHCb detector at a centre-of-mass energy of 7 ...TeV. The B0s→K0SK∗(892)0 decay is observed for the first time, with a significance of 7.1 standard deviations. The branching fraction is measured to beB(B0s→K0SK∗(892)0)=(10.9±2.5±1.2)×10−6,where the first uncertainty is statistical and the second is systematic. No evidence is found for the decay B0→K0SK∗(892)0 and an upper limit is set on the branching fraction, B(B0→K0SK∗(892)0)<0.64 ×10−6, at 90% confidence level. All results are consistent with Standard Model predictions.
The first observation of the B0s→D¯0K0S decay mode and evidence for the B0s→D¯∗0K0S decay mode are reported. The data sample corresponds to an integrated luminosity of 3.0 fb−1 collected in pp ...collisions by LHCb at center-of-mass energies of 7 and 8 TeV. The branching fractions are measured to beB(B0s→D¯0K¯0)B(B0s→D¯∗0K¯0)=(4.3±0.5(stat)±0.3(syst)±0.3(frag)±0.6(norm))×10−4,=(2.8±1.0(stat)±0.3(syst)±0.2(frag)±0.4(norm))×10−4,where the uncertainties are due to contributions coming from statistical precision, systematic effects, and the precision of two external inputs, the ratio fs/fd and the branching fraction of B0→D¯0K0S, which is used as a calibration channel.
A binned Dalitz plot analysis of the decays B0→DK∗0, with D→K0Sπ+π− and K0SK+K−, is performed to measure the observables x± and y±, which are related to the CKM angle γ and the hadronic parameters of ...the decays. The D decay strong phase variation over the Dalitz plot is taken from measurements performed at the CLEO-c experiment, making the analysis independent of the D decay model. With a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0fb−1, collected by the LHCb experiment, the values of the CP violation parameters are found to be x+=0.05±0.35±0.02, x−=−0.31±0.20±0.04, y+=−0.81±0.28±0.06 and y−=0.31±0.21±0.05, where the first uncertainties are statistical and the second systematic. These observables correspond to values γ = (71±20)∘, rB0=0.56±0.17 and δB0=(204+21−20)∘. The parameters rB0 and δB0 are the magnitude ratio and strong phase difference between the suppressed and favoured B0 decay amplitudes, and have been measured in a region of ±50 MeV/c2 around the K∗(892)0 mass and with the magnitude of the cosine of the K∗(892)0 helicity angle larger than 0.4.
We perform a search for near-threshold Ξ0b resonances decaying to Ξ−bπ+ in a sample of proton-proton collision data corresponding to an integrated luminosity of 3 fb−1 collected by the LHCb ...experiment. We observe one resonant state, with the following properties:m(Ξ∗0b)−m(Ξ−b)−m(π+)=15.727±0.068(stat)±0.023(syst)MeV/c2,Γ(Ξ∗0b)=0.90±0.16(stat)±0.08(syst)MeV.This confirms the previous observation by the CMS collaboration. The state is consistent with the JP=3/2+ Ξ∗0b resonance expected in the quark model. This is the most precise determination of the mass and the first measurement of the natural width of this state. We have also measured the ratioσ(pp→Ξ∗0bX)B(Ξ∗0b→Ξ−bπ+)σ(pp→Ξ−bX)=0.27±0.03(stat)±0.01(syst).
A search is performed for the charmless three-body decays of the Λ0b and Ξ0b baryons to the final states Λh+h′−, where h(′)=π or K. The analysis is based on a data sample, corresponding to an ...integrated luminosity of 3fb−1 of pp collisions, collected by the LHCb experiment. The Λ0b→ΛK+π− and Λ0b→ΛK+K− decays are observed for the first time and their branching fractions and CP asymmetry parameters are measured. Evidence is seen for the Λ0b→Λπ+π− decay and limits are set on the branching fractions of Ξ0b baryon decays to the Λh+h′− final states.
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