5,017 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

    In Vivo Evaluation of Antidiarrhoeal Activity of the Seed of Swietenia macrophylla King (Meliaceae)

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    Purpose: The seeds of Swietenia macrophylla are used in traditional medicine for the treatment of diarrhoea. Thus the petroleum ether extract of Swietenia macrophylla (Meliaceae) seeds was investigated for its anti-diarrhoeal property in Wister albino rats to substantiate folklore claim. Methods: Petroleum ether extract of the seeds of this plant, at graded doses (25, 50 & 100mg/kg body weight) was investigated for anti-diarrhoeal activity in term of reduction in the rate of defecation and consistency of faeces in castor oil induced diarrhoea. To understand the mechanism of its anti-diarrhoeal activity, its effect was further evaluated on intestinal transit and castor oil induced intestinal fluid accumulation (enteropooling). Results: At various doses (25, 50 & 100mg/kg body weight) the extract showed a remarkable anti-diarrhoeal activity evidenced by the reduction in the rate of defecation and consistency of faeces. Results are comparable to that of standard drug diphenoxylate (50mg/kg body weight). A single oral dose of Swietenia macrophylla extract of 100mg/kg body weight produced a significant decrease in the severity of diarrhoea. Extract produced profound decrease in intestinal transit (4.45 - 34.60%) also significantly inhibited castor oil induced enteropooling comparable to that of intraperitoneal injection of standard drug atropine sulphate at doses of 0.1 mg/kg body weight and 3 mg/kg body weight respectively. Conclusions: Experimental findings showed that petroleum ether extract of seeds of Swietenia macrophylla possess significant anti-diarrhoeal activity and may be a potent source of anti-diarrhoeal drug in future. Keywords: Swietenia macrophylla, anti-diarrhoeal activity, castor oil, atropine sulphate.> Tropical Journal of Pharmaceutical Research Vol. 6 (2) 2007: pp. 711-71
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