1,366,583 research outputs found
COVID-19 Dynamics: A Heterogeneous Model
No full textThe mathematical model reported here describes the dynamics of the ongoing coronavirus disease 2019 (COVID-19) epidemic, which is different in many aspects from the previous severe acute respiratory syndrome (SARS) epidemic. We developed this model when the COVID-19 epidemic was at its early phase. We reasoned that, with our model, the effects of different measures could be assessed for infection control. Unlike the homogeneous models, our model accounts for human population heterogeneity, where subpopulations (e.g., age groups) have different infection risks. The heterogeneous model estimates several characteristics of the epidemic more accurately compared to the homogeneous models. According to our analysis, the total number of infections and their peak number are lower compared to the assessment with the homogeneous models. Furthermore, the early-stage infection increase is little changed when population heterogeneity is considered, whereas the late-stage infection decrease slows. The model predicts that the anti-epidemic measures, like the ones undertaken in China and the rest of the world, decrease the basic reproductive number but do not result in the development of a sufficient collective immunity, which poses a risk of a second wave. More recent developments confirmed our conclusion that the epidemic has a high likelihood to restart after the quarantine measures are lifted. © Copyright © 2021 Gerasimov, Lebedev, Lebedev and Semenycheva
Measurement of the time-dependent CP asymmetry in B0 -> J/ψ KS0 decays
No full textThis Letter reports a measurement of the CP violation observables SJ/ψK0S and CJ/ψK0S in the decay channel B0→J/ψK0S performed with 1.0 fb−1 of pp collisions at s√=7 TeV collected by the LHCb experiment. The fit to the data yields SJ/ψK0S=0.73±0.07(stat)±0.04(syst) and CJ/ψK0S=0.03±0.09(stat)±0.01(syst). Both values are consistent with the current world averages and within
expectations from the Standard Model
First observation of Bs → J/ψf0(980) decays
No full textUsing data collected with the LHCb detector in proton–proton collisions at a centre-of-mass energy of 7 TeV, the hadronic decay is observed. This CP eigenstate mode could be used to measure mixing-induced CP violation in the system. Using a fit to the π+π− mass spectrum with interfering resonances gives . In the interval ±90 MeV around 980 MeV, corresponding to approximately two full f0 widths we also find , where in both cases the uncertainties are statistical and systematic, respectively
On the Lebedev transformation in Hardy's spaces
No full textWe establish the inverse Lebedev expansion with respect to
parameters and arguments of the modified Bessel functions for an
arbitrary function from Hardy's space H2,A, A>0. This gives another version of the Fourier-integral-type theorem for
the Lebedev transform. The result is generalized for a weighted
Hardy space H⌢2,A≡H⌢2((−A,A);|Γ(1+Rez+iτ)|2dτ), 0<A<1, of analytic functions f(z),z=Rez+iτ, in the strip |Rez|≤A. Boundedness and inversion properties
of the Lebedev transformation from this space into the space
L2(ℝ+;x−1dx) are considered. When Rez=0, we derive the familiar Plancherel theorem for the
Kontorovich-Lebedev transform
Dynamic Path Planning for a 7-DOF Robot Arm
No full textKlanke S, Lebedev DV, Haschke R, Steil JJ, Ritter H. Dynamic Path Planning for a 7-DOF Robot Arm. In: Int. Conf. Intelligent Robots and Systems. IEEE; 2006: 3879-3884
Measurement of the D+/- production asymmetry in 7 TeV pp collisions
No full textThe asymmetry in the production cross-section \sigma of D+/- mesons, A_P = (\sigma(D+) - \sigma(D-))/(\sigma(D+) + \sigma(D-)), is measured in bins of pseudorapidity \eta and transverse momentum p_T within the acceptance of the LHCb detector. The result is obtained with a sample of D+ -> K_S pi+ decays corresponding to an integrated luminosity of 1.0 fb^-1, collected in pp collisions at a centre of mass energy of 7 TeV at the Large Hadron Collider. When integrated over the kinematic range 2.0 K_S pi+ decay is negligible. No significant dependence on \eta or p_T is observed
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