32 research outputs found

    Microbiological profile and antibiotic resistance pattern of urinary tract infection in a tertiary care hospital

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    Urinary tract infection (UTI), of varying severity is one of the most commonly encountered ailments in nephrology outpatient department (OPD). The commonest pathogens causing community acquired UTI (CAUTI) are E. Coli, Proteus mirabilis, Pseudomonas aeruginosa and Klebsiella pneumonia. There is a rapidly rising trend of antibiotic resistance among these uropathogens, may be due to indiscriminate antibiotic usage and poor patient compliance. We conducted a retrospective analysis of all culture proven UTI cases that attended the nephrology OPD of S. K. hospital, Trivandrum from August 2017 to July 2019 (24 months). 130 males and 121 females were included in the study. The mean age of the study group was 62.8 years with a male predominance in the age group above 50 years and a female predisposition in less than 50 years group. Commonest pathogen isolated in urine culture was E. coli (52.98%) followed by Klebsiella (39.09%), Citrobacter (8.76%), Pseudomonas (8.37%), Enterobacter (2.39%), Enterococci (1.99%), Candida (1.59%), Acinetobacter (1.2%), Proteus (1.2%), Streptococci (1.2%) and Serratia (0.4%)

    Precise measurement of the Ds+D^+_s lifetime at Belle II

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    We measure the lifetime of the Ds+D_s^+ meson using a data sample of 207 fb1^{-1} collected by the Belle II experiment running at the SuperKEKB asymmetric-energy e+ee^+ e^- collider. The lifetime is determined by fitting the decay-time distribution of a sample of 116×103116\times 10^3 Ds+ϕπ+D_s^+\rightarrow\phi\pi^+ decays. Our result is \tau^{}_{D^+_s} = (498.7\pm 1.7\,^{+1.1}_{-0.8}) fs, where the first uncertainty is statistical and the second is systematic. This result is significantly more precise than previous measurements.Comment: 7 pages, 4 figures, to be submitted to Physical Review Letter

    Measurement of branching fractions and direct CPCP asymmetries for BKπB \to K\pi and BππB\to\pi\pi decays at Belle II

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    We report measurements of the branching fractions and direct CP\it{CP} asymmetries of the decays B0K+πB^0 \to K^+ \pi^-, B+K+π0B^+ \to K^+ \pi^0, B+K0π+B^+ \to K^0 \pi^+, and B0K0π0B^0 \to K^0 \pi^0, and use these for testing the standard model through an isospin-based sum rule. In addition, we measure the branching fraction and direct CP\it{CP} asymmetry of the decay B+π+π0B^+ \to \pi^+\pi^0 and the branching fraction of the decay B0π+πB^0 \to \pi^+\pi^-. The data are collected with the Belle II detector from e+ee^+e^- collisions at the Υ(4S)\Upsilon(4S) resonance produced by the SuperKEKB asymmetric-energy collider and contain 387×106387\times 10^6 bottom-antibottom meson pairs. Signal yields are determined in two-dimensional fits to background-discriminating variables, and range from 500 to 3900 decays, depending on the channel. We obtain 0.03±0.13±0.04-0.03 \pm 0.13 \pm 0.04 for the sum rule, in agreement with the standard model expectation of zero and with a precision comparable to the best existing determinations

    Observation of BD()KKS0{B\to D^{(*)} K^- K^{0}_S} decays using the 2019-2022 Belle II data sample

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    We present a measurement of the branching fractions of four B0,D()+,0KKS0B^{0,-}\to D^{(*)+,0} K^- K^{0}_S decay modes. The measurement is based on data from SuperKEKB electron-positron collisions at the Υ(4S)\Upsilon(4S) resonance collected with the Belle II detector and corresponding to an integrated luminosity of 362 fb1{362~\text{fb}^{-1}}. The event yields are extracted from fits to the distributions of the difference between expected and observed BB meson energy to separate signal and background, and are efficiency-corrected as a function of the invariant mass of the KKS0K^-K_S^0 system. We find the branching fractions to be: B(BD0KKS0)=(1.89±0.16±0.10)×104, \text{B}(B^-\to D^0K^-K_S^0)=(1.89\pm 0.16\pm 0.10)\times 10^{-4}, B(B0D+KKS0)=(0.85±0.11±0.05)×104, \text{B}(\overline B{}^0\to D^+K^-K_S^0)=(0.85\pm 0.11\pm 0.05)\times 10^{-4}, B(BD0KKS0)=(1.57±0.27±0.12)×104, \text{B}(B^-\to D^{*0}K^-K_S^0)=(1.57\pm 0.27\pm 0.12)\times 10^{-4}, B(B0D+KKS0)=(0.96±0.18±0.06)×104, \text{B}(\overline B{}^0\to D^{*+}K^-K_S^0)=(0.96\pm 0.18\pm 0.06)\times 10^{-4}, where the first uncertainty is statistical and the second systematic. These results include the first observation of B0D+KKS0\overline B{}^0\to D^+K^-K_S^0, BD0KKS0B^-\to D^{*0}K^-K_S^0, and B0D+KKS0\overline B{}^0\to D^{*+}K^-K_S^0 decays and a significant improvement in the precision of B(BD0KKS0)\text{B}(B^-\to D^0K^-K_S^0) compared to previous measurements

    Measurement of C ⁣PC\!P asymmetries and branching-fraction ratios for B±DK±B^\pm \to DK^\pm and Dπ±D\pi^\pm with DKS0K±πD\to K^0_{\rm S} K^\pm\pi^\mp using Belle and Belle II data

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    We measure C ⁣PC\!P asymmetries and branching-fraction ratios for B±DK±B^\pm \to DK^\pm and Dπ±D\pi^\pm decays with DKS0K±πD\to K^0_{\rm S} K^\pm\pi^\mp, where DD is a superposition of D0D^0 and Dˉ0\bar{D}^0. We use the full data set of the Belle experiment, containing 772×106 BBˉ772\times 10^6~B\bar{B} pairs, and data from the Belle~II experiment, containing 387×106 BBˉ387\times 10^6~B\bar{B} pairs, both collected in electron-positron collisions at the Υ(4S)\Upsilon(4S) resonance. Our results provide model-independent information on the unitarity triangle angle ϕ3\phi_3.Comment: 26 pages, 8 figure

    Tests of light-lepton universality in angular asymmetries of B0DνB^0 \to D^{*-} \ell \nu decays

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    We present the first comprehensive tests of light-lepton universality in the angular distributions of semileptonic \Bz-meson decays to charged spin-1 charmed mesons. We measure five angular-asymmetry observables as functions of the decay recoil that are sensitive to lepton-universality-violating contributions. We use events where one neutral \B is fully reconstructed in \PUpsilonFourS{} \to\B\overline{B} decays in data corresponding to \lumion integrated luminosity from electron-positron collisions collected with the \belletwo detector. We find no significant deviation from the standard model expectations

    First measurement of R(Xτ/)R(X_{\tau/\ell}) as an inclusive test of the bcτνb \to c \tau \nu anomaly

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    We measure the tau-to-light-lepton ratio of inclusive BB-meson branching fractions R(Xτ/)B(BXτν)/B(BXν)R(X_{\tau/\ell}) \equiv \mathcal{B}(B\to X \tau \nu)/\mathcal{B}(B \to X \ell \nu), where \ell indicates an electron or muon, and thereby test the universality of charged-current weak interactions. We select events that have one fully reconstructed BB meson and a charged lepton candidate from 189 fb1189~\mathrm{fb}^{-1} of electron-positron collision data collected with the Belle II detector. We find R(Xτ/)=0.228±0.016 (stat)±0.036 (syst)R(X_{\tau/\ell}) = 0.228 \pm 0.016~(\mathrm{stat}) \pm 0.036~(\mathrm{syst}), in agreement with standard-model expectations. This is the first direct measurement of R(Xτ/)R(X_{\tau/\ell})

    Measurement of the τ\tau-lepton mass with the Belle~II experiment

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    We present a measurement of the τ\tau-lepton mass using a sample of about 175 million e+eτ+τe^+e^- \to \tau^+\tau^- events collected with the Belle II detector at the SuperKEKB e+ee^+e^- collider at a center-of-mass energy of 10.579GeV10.579\,\mathrm{Ge\kern -0.1em V}. This sample corresponds to an integrated luminosity of 190fb1190\,\mathrm{fb^{-1}}. We use the kinematic edge of the τ\tau pseudomass distribution in the decay τππ+πντ{\tau^-\to\pi^-\pi^+\pi^-\nu_\tau} and measure the τ\tau mass to be 1777.09±0.08±0.11MeV ⁣/c21777.09 \pm 0.08 \pm 0.11 \,\mathrm{Me\kern -0.1em V\!/c^2}, where the first uncertainty is statistical and the second systematic. This result is the most precise to date

    Measurement of the branching fraction and CP\it CP asymmetry of B0π0π0B^{0} \rightarrow \pi^{0} \pi^{0} decays using 198×106198 \times 10^6 BBB\overline{B} pairs in Belle II data

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    We report measurements of the branching fraction and CP\it CP asymmetry in B0π0π0B^{0} \to \pi^{0} \pi^{0} decays reconstructed at Belle II in an electron-positron collision sample containing 198×106198 \times 10^{6} BBB\overline{B} pairs. We measure a branching fraction \mathcal{B}(\Bpipi) = (1.38 \pm 0.27 \pm 0.22) \times 10^{-6} and a CP\it CP asymmetry \Acp(\Bpipi) = 0.14 \pm 0.46 \pm 0.07, where the first uncertainty is statistical and the second is systematic

    Reconstruction of BρνB \to \rho \ell \nu_\ell decays identified using hadronic decays of the recoil BB meson in 2019 -- 2021 Belle II data

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    We present results on the semileptonic decays B0ρ+νB^0 \to \rho^- \ell^+ \nu_\ell and B+ρ0+νB^+ \to \rho^0 \ell^+ \nu_\ell in a sample corresponding to 189.9/fb of Belle II data at the SuperKEKB ee+e^- e^+ collider. Signal decays are identified using full reconstruction of the recoil BB meson in hadronic final states. We determine the total branching fractions via fits to the distributions of the square of the "missing" mass in the event and the dipion mass in the signal candidate and find B(B0ρ+ν)=(4.12±0.64(stat)±1.16(syst))×104{\mathcal{B}(B^0\to\rho^-\ell^+ \nu_\ell) = (4.12 \pm 0.64(\mathrm{stat}) \pm 1.16(\mathrm{syst})) \times 10^{-4}} and B(B+ρ0+ν)=(1.77±0.23(stat)±0.36(syst))×104{\mathcal{B}({B^+\to\rho^0\ell^+\nu_\ell}) = (1.77 \pm 0.23 (\mathrm{stat}) \pm 0.36 (\mathrm{syst})) \times 10^{-4}} where the dominant systematic uncertainty comes from modeling the nonresonant B(ππ)+νB\to (\pi\pi)\ell^+\nu_\ell contribution
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