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## Observation of Transverse Λ / Λ Hyperon Polarization in e+e- Annihilation at Belle

We report the first observation of the spontaneous polarization of Λ and Λ hyperons transverse to the production plane in e+e- annihilation, which is attributed to the effect arising from a polarizing fragmentation function. For inclusive Λ/Λ production, we also report results with subtracted feed-down contributions from Σ0 and charm. This measurement uses a dataset of 800.4 fb-1 collected by the Belle experiment at or near a center-of-mass energy of 10.58 GeV. We observe a significant polarization that rises with the fractional energy carried by the Λ/Λ hyperon. © 2019 authors.

We present first evidence that the cosine of the CP-violating weak phase 2β is positive, and hence exclude trigonometric multifold solutions of the Cabibbo-Kobayashi-Maskawa (CKM) Unitarity Triangle using a time-dependent Dalitz plot analysis of B0→D(∗)h0 with D→KS0π+π- decays, where h0 {π0,η,ω} denotes a light unflavored and neutral hadron. The measurement is performed combining the final data sets of the BABAR and Belle experiments collected at the (4S) resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×106BB pairs recorded by the BABAR detector and (772±11)×106BB pairs recorded by the Belle detector. The results of the measurement are sin2β=0.80±0.14(stat)±0.06(syst)±0.03(model) and cos2β=0.91±0.22(stat)±0.09(syst)±0.07(model). The result for the direct measurement of the angle β of the CKM Unitarity Triangle is β=[22.5±4.4(stat)±1.2(syst)±0.6(model)]°. The measurement assumes no direct CP violation in B0→D(∗)h0 decays. The quoted model uncertainties are due to the composition of the D0→KS0π+π- decay amplitude model, which is newly established by performing a Dalitz plot amplitude analysis using a high-statistics e+e-→cc data sample. CP violation is observed in B0→D(∗)h0 decays at the level of 5.1 standard deviations. The significance for cos2β>0 is 3.7 standard deviations. The trigonometric multifold solution π/2-β=(68.1±0.7)° is excluded at the level of 7.3 standard deviations. The measurement resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle. © 2018 authors. Published by the American Physical Society.

We present a new measurement of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb| from B0→D∗-ℓ+νℓ decays, reconstructed with the full Belle data set of 711 fb-1 integrated luminosity. Two form factor parametrizations, originally conceived by the Caprini-Lellouch-Neubert (CLN) and the Boyd, Grinstein and Lebed (BGL) groups, are used to extract the product F(1)ηEW|Vcb| and the decay form factors, where F(1) is the normalization factor and ηEW is a small electroweak correction. In the CLN parametrization we find F(1)ηEW|Vcb|=(35.06±0.15±0.56)×10-3, ρ2=1.106±0.031±0.007, R1(1)=1.229±0.028±0.009, R2(1)=0.852±0.021±0.006. For the BGL parametrization we obtain F(1)ηEW|Vcb|=(34.93±0.23±0.59)×10-3, which is consistent with the world average when correcting for F(1)ηEW. The branching fraction of B0→D∗-ℓ+νℓ is measured to be B(B0→D∗-ℓ+νℓ)=(4.90±0.02±0.16)%. We also present a new test of lepton flavor universality violation in semileptonic B decays, B(B0→D∗-e+ν)B(B0→D∗-μ+ν)=1.01±0.01±0.03. The errors quoted correspond to the statistical and systematic uncertainties, respectively. This is the most precise measurement of F(1)ηEW|Vcb| and form factors to date and the first experimental study of the BGL form factor parametrization in an experimental measurement. © 2019 authors. Published by the American Physical Society.

We present the result of the search for the rare B meson decay of B+→+νγ with =e,μ. For the search the full data set recorded by the Belle experiment of 711 fb-1 integrated luminosity near the (4S) resonance is used. Signal candidates are reconstructed for photon energies Eγ larger than 1 GeV using a novel multivariate tagging algorithm. The novel algorithm fully reconstructs the second B meson produced in the collision using hadronic modes and was specifically trained to recognize the signal signature in combination with hadronic tag-side B meson decays. This approach greatly enhances the performance. Background processes that can mimic this signature, mainly charmless semileptonic decays and continuum processes, are suppressed using multivariate methods. The number of signal candidates is determined by analyzing the missing mass squared distribution as inferred from the signal side particles and the kinematic properties of the tag-side B meson. No significant excess over the background-only hypothesis is observed and upper limits on the partial branching fraction ΔB with Eγ>1 GeV individually for electron and muon final states as well as for the average branching fraction of both lepton final states are reported. We find a Bayesian upper limit of ΔB(B+→+νγ)<3.0×10-6 at 90% CL and also report an upper limit on the first inverse moment of the light-cone distribution amplitude of the B meson of λB>0.24 GeV at 90% CL. © 2018 authors. Published by the American Physical Society.

The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.

Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.

This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .

The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.