4,221 research outputs found

    Molecular Typing of Trypanosoma cruzi Isolates, United States

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    Studies have characterized Trypanosoma cruzi from parasite-endemic regions. With new human cases, increasing numbers of veterinary cases, and influx of potentially infected immigrants, understanding the ecology of this organism in the United States is imperative. We used a classic typing scheme to determine the lineage of 107 isolates from various hosts

    Autochthonous Transmission of Trypanosoma cruzi, Louisiana

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    Autochthonous transmission of the Chagas disease parasite, Trypanosoma cruzi, was detected in a patient in rural New Orleans, Louisiana. The patient had positive test results from 2 serologic tests and hemoculture. Fifty-six percent of 18 Triatoma sanguisuga collected from the house of the patient were positive for T. cruzi by PCR

    Influenza A Virus H5–specific Antibodies in Mute Swans (\u3ci\u3eCygnus olor\u3c/i\u3e) in the USA

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    The use of serologic assays for influenza A virus (IAV) surveillance in wild birds has increased because of the availability of commercial enzyme-linked immunosorbent assays (ELISAs). Recently, an H5-specific blocking ELISA (bELISA) was shown to reliably detect H5-specific antibodies to low- and highpathogenic H5 viruses in experimentally infected waterfowl. Mute Swans (Cygnus olor) were frequently associated with highly pathogenic H5N1 outbreaks in Europe and may have a similar role if highly pathogenic H5N1 is introduced into North America. We measured the prevalence of antibodies to the nucleoprotein and H5 protein in Mute Swans using three serologic assays. We collected 340 serum samples from Mute Swans in Michigan, New Jersey, New York, and Rhode Island, US. We detected antibodies to the IAV nucleoprotein in 66.2% (225/340) of the samples. We detected H5-specific antibodies in 62.9% (214/340) and 18.8% (64/340) using a modified H5 bELISA protocol and hemagglutination inhibition (HI) assay, respectively. The modified H5 bELISA protocol detected significantly more positive samples than did the manufacturer’s protocol. We also tested 46 samples using virus neutralization. Neutralization results had high agreement with the modified H5 bELISA protocol and detected a higher prevalence than did the HI assay. These results indicate that North American Mute Swans have high nucleoprotein and H5 antibody prevalences

    Evidence for direct CP violation in the decay B->D(*)K, D->KsPi+Pi- and measurement of the CKM phase phi3

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    We present a new measurement of the unitarity triangle angle phi3 using a Dalitz plot analysis of the KsPi+Pi- decay of the neutral D meson produced in B->D(*)K decays. The method exploits the interference between D0 and D0bar to extract the angle phi3, strong phase delta and the ratio r of suppressed and allowed amplitudes. We apply this method to a 605 fb-1 data sample collected by the Belle experiment. The analysis uses three decays: B->DK, and B->D*K with D*->DPi0 and D*->Dgamma, as well as the corresponding charge-conjugate modes. From a combined maximum likelihood fit to the three modes, we obtain phi3 = 78.4^+10.8_-11.6 +- 3.6 (syst) +- 8.9 (model) degrees. CP conservation in this process is ruled out at the confidence level (1-CL)=5x10^-4, or 3.5 standard deviations.Comment: 10 pages, 5 figures, 4 tables. Replaced by version published in Phys. Rev.

    Heisenberg's Uncertainty Relation and Bell Inequalities in High Energy Physics

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    An effective formalism is developed to handle decaying two-state systems. Herewith, observables of such systems can be described by a single operator in the Heisenberg picture. This allows for using the usual framework in quantum information theory and, hence, to enlighten the quantum feature of such systems compared to non-decaying systems. We apply it to systems in high energy physics, i.e. to oscillating meson-antimeson systems. In particular, we discuss the entropic Heisenberg uncertainty relation for observables measured at different times at accelerator facilities including the effect of CP violation, i.e. the imbalance of matter and antimatter. An operator-form of Bell inequalities for systems in high energy physics is presented, i.e. a Bell-witness operator, which allows for simple analysis of unstable systems.Comment: 17 page

    First study of \eta_c, \eta(1760) and X(1835) production via \eta'\pi^+\pi^- final states in two-photon collisions

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    The invariant mass spectrum of the \eta' \pi^+ \pi^- final state produced in two-photon collisions is obtained using a 673 fb^{-1} data sample collected in the vicinity of the \Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We observe a clear signal of the \eta_c and measure its mass and width to be M(\eta_c)=(2982.7 +- 1.8(stat) +- 2.2(syst) +- 0.3(model)) MeV/c^2 and \Gamma(\eta_c) = (37.8^{+5.8}_{-5.3}(stat) +- 2.8(syst) +- 1.4(model)) MeV/c^2. The third error is an uncertainty due to possible interference between the \eta_c and a non-resonant component. We also report the first evidence for \eta(1760) decay to \eta' \pi^+ \pi^-; we find two solutions for its parameters, depending on the inclusion or not of the X(1835), whose existence is of marginal significance in our data. From a fit to the mass spectrum using coherent X(1835) and \eta(1760) resonant amplitudes, we set a 90% confidence level upper limit on the product \Gamma_{\gamma\gamma} \BR (\eta' \pi^+ \pi^-) for the X(1835).Comment: 13 pages, 7 figures, submitted to PR

    Search for CP violation in the decays D(s)+→KS0π+D^+_{(s)} \to K_S^0\pi^+ and D(s)+→KS0K+D^+_{(s)} \to K_S^0K^+

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    We have searched for CP violation in the charmed meson decays D(s)+→KS0π+D^{+}_{(s)}\to K^0_S\pi^+ and D(s)+→KS0K+D^{+}_{(s)}\to K^0_S K^+ using 673 fb−1^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+e−e^+e^- collider. No evidence for CP violation is observed. We report the most sensitive CP asymmetry measurements to date for these decays: ACPD+→KS0π+=(−0.71±0.19±0.20)A_{CP}^{D^+\to K^0_S\pi^+}=(-0.71\pm0.19\pm0.20)%, ACPDs+→KS0π+=(+5.45±2.50±0.33)A_{CP}^{D^+_s\to K^0_S\pi^+}=(+5.45\pm2.50\pm0.33)%, ACPD+→KS0K+=(−0.16±0.58±0.25)A_{CP}^{D^+\to K^0_S K^+}=(-0.16\pm0.58\pm0.25)%, and ACPDs+→KS0K+=(+0.12±0.36±0.22)A_{CP}^{D^+_s\to K^0_S K^+}=(+0.12\pm0.36\pm0.22)%, where the first uncertainties are statistical and the second are systematic

    Evidence for a new resonance and search for the Y(4140) in ÎłÎłâ†’Ï•J/ψ\gamma \gamma \to \phi J/\psi

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    The process \gamma \gamma \to \phi \jpsi is measured for \phi \jpsi masses between threshold and 5 GeV/c2{\it c}^2, using a data sample of 825 fb−1^{-1} collected with the Belle detector. A narrow peak of 8.8−3.2+4.28.8^{+4.2}_{-3.2} events, with a significance of 3.2 standard deviations including systematic uncertainty, is observed. The mass and natural width of the structure (named X(4350)) are measured to be (4350.6−5.1+4.6(stat)±0.7(syst))MeV/c2(4350.6^{+4.6}_{-5.1}(\rm{stat})\pm 0.7(\rm{syst})) \hbox{MeV}/{\it c}^2 and (13−9+18(stat)±4(syst))MeV(13^{+18}_{-9}(\rm{stat})\pm 4(\rm{syst})) \hbox{MeV}, respectively. The product of its two-photon decay width and branching fraction to \phi\jpsi is (6.7−2.4+3.2(stat)±1.1(syst))eV(6.7^{+3.2}_{-2.4}(\rm{stat}) \pm 1.1(\rm{syst})) \hbox{eV} for JP=0+J^P=0^+, or (1.5−0.6+0.7(stat)±0.3(syst))eV(1.5^{+0.7}_{-0.6}(\rm{stat}) \pm 0.3(\rm{syst})) \hbox{eV} for JP=2+J^P=2^+. No signal for the Y(4140)\to \phi \jpsi structure reported by the CDF Collaboration in B\to K^+ \phi \jpsi decays is observed, and limits of \Gamma_{\gamma \gamma}(Y(4140)) \BR(Y(4140)\to\phi \jpsi)<41 \hbox{eV} for JP=0+J^P=0^+ or <6.0eV<6.0 \hbox{eV} for JP=2+J^P=2^+ are determined at the 90% C.L. This disfavors the scenario in which the Y(4140) is a Ds∗+Ds∗−D_{s}^{\ast+} {D}_{s}^{\ast-} molecule.Comment: 9 pages, 3 figures, publication in Phys. Rev. Lett. 104, 112004, 201

    Measurements of time-dependent CP asymmetries in B→D∗∓π±B \to D^{*\mp} \pi^{\pm} decays using a partial reconstruction technique

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    We report results on time-dependent CP asymmetries in B→D∗∓π±B \to D^{*\mp}\pi^{\pm} decays based on a data sample containing 657 {\times} 10610^6 BBˉB\bar{B} pairs collected with the Belle detector at the KEKB asymmetric-energy e+e−e^+ e^- collider at the ΄(4S)\Upsilon(4S) resonance. We use a partial reconstruction technique, wherein signal B→D∗∓π±B \to D^{*\mp}\pi^{\pm} events are identified using information only from the fast pion from the B decay and the slow pion from the subsequent decay of the D∗∓D^{*\mp}, where the former (latter) corresponds to D∗+(D∗−)D^{*+} (D^{*-}) final states. We obtain CP violation parameters S+=+0.061±0.018(stat)±0.012(syst)S^+ = +0.061 \pm 0.018(\mathrm{stat}) \pm 0.012(\mathrm{syst}) and S−=+0.031±0.019(stat)±0.015(syst)S^- = +0.031 \pm 0.019(\mathrm{stat}) \pm 0.015(\mathrm{syst}).Comment: 8 pages, 5 figures, 2 tables, submitted to Physical Review D (RC

    Search for the exotic Θ+\Theta^+ resonance in the NOMAD experiment

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    A search for exotic Theta baryon via Theta -> proton +Ks decay mode in the NOMAD muon neutrino DIS data is reported. The special background generation procedure was developed. The proton identification criteria are tuned to maximize the sensitivity to the Theta signal as a function of xF which allows to study the Theta production mechanism. We do not observe any evidence for the Theta state in the NOMAD data. We provide an upper limit on Theta production rate at 90% CL as 2.13 per 1000 of neutrino interactions.Comment: Accepted to European Physics Journal
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