4,129 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

    Al-Ṭabarī and the Dynamics of tafsīr: Theological Dimensions of a Legacy.

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    The Jāmiʿ al-bayān ʿan taʾwīl ayy al-Qurʾān is fittingly recognised as representing an important milestone in the history of the discipline of tafsīr: within the work, al-Ṭabarī accomplished a uniquely comprehensive exegetical synthesis of literary, grammatical, legal and theological elements, bringing a broader sense of definition and purpose to the discipline of tafsīr. Among the characteristic features of the scholarship of al-Ṭabarī are the objectivity and consistency he brought to his work and such qualities resonate in his gauging of theological issues and topics. While it has been customary to view al-Ṭabarī’s theology as being strictly informed by a rigidly traditionalist methodology, a circumspect review of theological discussions in the tafsīr reveals not only the author’s accomplished marshalling of the attendant arguments and theses, but also the spirit of autonomy and resourcefulness with which he assesses points of doctrine and dogma. In this article an attempt is made to analyse aspects of the intertwined theological discourses of the tafsīr and related treatises, bridging them with materials articulated in the biographical sources. The aim is to explore the relationship between his approach to scholarship along with the standpoints to which he adhered and their impact upon attitudes towards his remarkable work and legacy. Key words: Tafsīr; Islamic theology; al-Ṭabarī; istiwāʾ; ism and musammā; Arabic grammarians; classical Arabic biograph
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