MicroBooNE is a neutrino experiment located in the Booster Neutrino Beamline (BNB) at Fermilab, which collected data from 2015 to 2021. MicroBooNE's liquid argon time projection chamber (LArTPC) is ...accompanied by a photon detection system consisting of 32 photomultiplier tubes used to measure the argon scintillation light and determine the timing of neutrino interactions. Analysis techniques combining light signals and reconstructed tracks are applied to achieve a neutrino interaction time resolution of \(\mathcal{O}(1\,\text{ns})\). The result obtained allows MicroBooNE to access the ns neutrino pulse structure of the BNB for the first time. The timing resolution achieved will enable significant enhancement of cosmic background rejection for all neutrino analyses. Furthermore, the ns timing resolution opens new avenues to search for long-lived-particles such as heavy neutral leptons in MicroBooNE, as well as in future large LArTPC experiments, namely the SBN program and DUNE.
In liquid argon time projection chambers exposed to neutrino beams and running on or near surface levels, cosmic muons and other cosmic particles are incident on the detectors while a single ...neutrino-induced event is being recorded. In practice, this means that data from surface liquid argon time projection chambers will be dominated by cosmic particles, both as a source of event triggers and as the majority of the particle count in true neutrino-triggered events. In this work, we demonstrate a novel application of deep learning techniques to remove these background particles by applying semantic segmentation on full detector images from the SBND detector, the near detector in the Fermilab Short-Baseline Neutrino Program. We use this technique to identify, at single image-pixel level, whether recorded activity originated from cosmic particles or neutrino interactions.
We present a study of three B{sup 0} decay modes useful for time-dependent CP asymmetry measurements. From a sample of 9.7x10{sup 6} BB(bar sign) meson pairs collected with the CLEO detector, we have ...reconstructed B{sup 0}{yields}J/{psi}K{sub S}{sup 0}, B{sup 0}{yields}{chi}{sub c1}K{sub S}{sup 0}, and B{sup 0}{yields}J/{psi}{pi}{sup 0} decays. The latter two decay modes have been observed for the first time. We describe a K{sub S}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} detection technique and its application to the reconstruction of the decay B{sup 0}{yields}J/{psi}K{sub S}{sup 0}. Combining the results obtained using K{sub S}{sup 0}{yields}{pi}{sup +}{pi}{sup -} and K{sub S}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} decays, we determine B(B{sup 0}{yields}J/{psi}K{sup 0})=(9.5{+-}0.8{+-}0.6)x10{sup -4}, where the first uncertainty is statistical and the second one is systematic. We also obtain B(B{sup 0}{yields}{chi}{sub c1}K{sup 0})=(3.9{sub -1.3}{sup +1.9}{+-}0.4)x10{sup -4} and B(B{sup 0}{yields}J/{psi}{pi}{sup 0})=(2.5{sub -0.9}{sup +1.1}{+-}0.2)x10{sup -5}. (c) 2000 The American Physical Society.
The nuclear two-photon or double-gamma (\(2\gamma\)) decay is a second-order electromagnetic process whereby a nucleus in an excited state emits two gamma rays simultaneously. To be able to directly ...measure the \(2\gamma\) decay rate in the low-energy regime below the electron-positron pair-creation threshold, we combined the isochronous mode of a storage ring with Schottky resonant cavities. The newly developed technique can be applied to isomers with excitation energies down to \(\sim100\)\,keV and half-lives as short as \(\sim10\)\,ms. The half-life for the \(2\gamma\) decay of the first-excited \(0^+\) state in bare \(^{72}\mathrm{Ge}\) ions was determined to be \(23.9\left(6\right)\)\,ms, which strongly deviates from expectations.
We report on a study of the invariant mass spectrum of the hadronic system in the decay {tau}{sup -}{yields}{pi}{sup -}{pi}{sup 0}{nu}{sub {tau}}. This study was performed with data obtained with the ...CLEO II detector operating at the CESR e{sup +}e{sup -} collider. We present fits to phenomenological models in which resonance parameters associated with the {rho}(770) and {rho}(1450) mesons are determined. The {pi}{sup -}{pi}{sup 0} spectral function inferred from the invariant mass spectrum is compared with data on e{sup +}e{sup -}{yields}{pi}{sup +}{pi}{sup -} as a test of the conserved vector current theorem. We also discuss the implications of our data with regard to estimates of the hadronic contribution to the muon anomalous magnetic moment. (c) 2000 The American Physical Society.
Immunosuppressed patients occasionally suffer from a multifocal infection with Nocardia. It is important to distinguish Nocardia farcinica from Nocardia asteroides, because of different sensitivity ...against antibiotics.
A 40-year-old patient with polycystic renal disease successfully underwent a kidney transplantation without complications. Immunosuppression consisted of: corticosteroids, azathioprin and ciclosporin A. Ten weeks later he developed acute choroiditis with consecutive retinal detachment and neovascular glaucoma in one eye. In addition, 14 weeks after transplantation CT scans revealed multiple cerebral abscesses.
In the course of the disease Nocardia farcinica (N. f.) was identified by cerebral stereotactic biopsy of a cerebral lesion, histological examination of the enucleated globe and sputum culture. Histologically filamentous, eosinophilic organisms were found. Microbiology identified aerobic actinomycetes in cultures and Nocardia farcinica by PCR. Therapeutically the combination of vancomycin, ampicillin, and sulbactam was successful.
In immunosuppressed patients Nocardia farcinica can become life-threatening. One of the first manifestations may be a choroiditis. Infection of the respiratory tract followed by hematogenous spread is the common way of systemic nocardiosis. Biopsy followed by identification of species by PCR is recommended because of the specific therapeutic strategies associated with each species.
We present the first measurement of the cross section of Cabibbo-suppressed \(\Lambda\) baryon production, using data collected with the MicroBooNE detector when exposed to the neutrinos from the ...Main Injector beam at the Fermi National Accelerator Laboratory. The data analyzed correspond to \(2.2 \times 10^{20}\) protons on target of neutrino mode running and \(4.9 \times 10^{20}\) protons on target of anti-neutrino mode running. An automated selection is combined with hand scanning, with the former identifying five candidate \(\Lambda\) production events when the signal was unblinded, consistent with the GENIE prediction of \(5.3 \pm 1.1\) events. Several scanners were employed, selecting between three and five events, compared with a prediction from a blinded Monte Carlo simulation study of \(3.7 \pm 1.0\) events. Restricting the phase space to only include \(\Lambda\) baryons that decay above MicroBooNE's detection thresholds, we obtain a flux averaged cross section of \(2.0^{+2.2}_{-1.7} \times 10^{-40}\) cm\(^2/\)Ar, where statistical and systematic uncertainties are combined.
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