707 research outputs found

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

    Terahertz Crystal of the System TlBr0.46 I0.54 – AgI

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    FIELD: terahertz materials. SUBSTANCE: invention relates to a new halide crystalline class of terahertz (THz) materials based on solid solutions of monovalent thallium and silver. A terahertz crystal of the TlBr0.46I0.54 - AgI system includes a solid solution of TlBr0.46I0.54 and silver halide, while it is based on a solid solution and additionally contains silver iodide in the following ratio of components: solid solution TlBr0.46I0.54 - 98, 0-82.0 mol.%; silver iodide - 2.0-18.0 mol.%. EFFECT: invention provides TlBr0.46I0.54- AgI, photo and radiation-resistant, non-hygroscopic and plastic, highly industrial in a terarier range from 0.1 to 30.0 THz (from 3000 to 10 μm), as well as in visible and infrared, as well as in visible and infrared; the areas of without absorption windows from 0.5 to 60.0 microns, which opens wide areas of application as optical products and fibers for teraring technologies, photonics, laser and IR fiber optics. 1 cl, 1 dwg, 3 ex.Изобретение относится к новому галогенидному кристаллическому классу терагерцовых (ТГц) материалов на основе твердых растворов одновалентного таллия и серебра. Терагерцовый кристалл системы TlBr0,46I0,54 - AgI включает твердый раствор TlBr0,46I0,54 и галогенид серебра, при этом он выполнен на основе твердого раствора и дополнительно содержит йодид серебра при следующем соотношении компонентов: твердый раствор TlBr0,46I0,54 - 98,0-82,0 мол. %; йодид серебра - 2,0-18,0 мол. %. Изобретение обеспечивает терагерцовые кристаллы системы TlBr0,46I0,54 – AgI, фото- и радиационно стойкие, негигроскопичные и пластичные, высокопрозрачные в терагерцовом диапазоне от 0,1 до 30,0 ТГц (от 3000 до 10 мкм), а также в видимой и инфракрасной области без окон поглощения от 0,5 до 60,0 мкм, что открывает широкие области применения в качестве оптических изделий и волоконных световодов для терагерцовых технологий, фотоники, лазерной и ИК волоконной оптики. 1 ил., 3 пр
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