347 research outputs found
Pion-proton correlation in neutrino interactions on nuclei
In neutrino-nucleus interactions, a proton produced with a correlated pion
might exhibit a left-right asymmetry relative to the lepton scattering plane
even when the pion is absorbed. Absent in other proton production mechanisms,
such an asymmetry measured in charged-current pionless production could reveal
the details of the absorbed-pion events that are otherwise inaccessible. In
this study, we demonstrate the idea of using final-state proton left-right
asymmetries to quantify the absorbed-pion event fraction and underlying
kinematics. This technique might provide critical information that helps
constrain all underlying channels in neutrino-nucleus interactions in the GeV
regime.Comment: 7 pages, 4 figure
Pivotal technologies for the public library : 2014
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The effect of ε-aminocaproic acid on blood product requirement, outcome and thromboelastography parameters in severely thrombocytopenic dogs
Background: No treatment other than platelet administration is known to protect against spontaneous hemorrhage in thrombocytopenic dogs. Objectives: Primary: determine if treatment with ε-aminocaproic acid (EACA) decreases the requirement for blood transfusions and improves outcome in dogs with severe thrombocytopenia. Secondary: find evidence of hyperfibrinolysis and determine the effect EACA administration on rapid (rTEG) and tissue plasminogen activator-spiked (tPA-rTEG) thromboelastography parameters. Animals: Twenty-seven dogs with severe thrombocytopenia were treated with EACA, and data from an additional 33 were obtained from the hospital database as historical control (HC) cohort. Methods: Single arm clinical trial with HCs. The EACA group dogs received EACA (100 mg/kg IV followed by a constant-rate infusion [CRI] of 400 mg/kg/24 hours). Thromboelastography before and during EACA infusion, hospitalization days, number of transfusions, and mortality were compared. Results: No difference was found in number of transfusions per dog (median, interquartile range; 1, 0-2.5 vs 0.9, 0-2; P =.5) and hospitalization days (4, 4-6 vs 4.5, 3.75-6; P =.83) between HC and EACA groups, respectively, and no difference in survival was identified by log-rank analysis (P =.15). Maximum amplitude on both rTEG and tPA-rTEG increased after EACA administration (rTEG baseline: 23.6, 9.6-38.9; post-EACA: 27.3, 19.8-43.2; P <.001; tPA-rTEG baseline: 23, 10.9-37.2; post-EACA: 24.7, 16.7-44.8; P <.002). Conclusions and Clinical Importance: Although EACA increased clot strength, there was no effect on outcome. Treatment with EACA at this dosage cannot be recommended as a routine treatment but may be considered for dogs with severe ongoing hemorrhage.</p
Radiative corrections to inverse muon decay for accelerator neutrinos
Inverse muon decay () is a promising tool to
constrain neutrino fluxes with energies .
Radiative corrections introduce percent-level distortions to energy spectra of
outgoing muons and depend on experimental details. In this paper, we generalize
the calculation of radiative corrections in muon decay to the scattering
processes and . We evaluate virtual and real
contributions and present the muon energy spectrum for both channels,
double-differential distributions in muon energy and muon scattering angle, in
photon energy and photon scattering angle, and photon energy spectrum for the
dominant process. We discuss how radiative
corrections modify experimentally interesting distributions.Comment: 21 pages, 8 figures, v2, structure changed, new cross sections adde
Direct Measurement of Nuclear Dependence of Charged Current Quasielastic-like Neutrino Interactions using MINERvA
Charged-current interactions on carbon, iron, and lead with a
final state hadronic system of one or more protons with zero mesons are used to
investigate the influence of the nuclear environment on quasielastic-like
interactions. The transfered four-momentum squared to the target nucleus,
, is reconstructed based on the kinematics of the leading proton, and
differential cross sections versus and the cross-section ratios of iron,
lead and carbon to scintillator are measured for the first time in a single
experiment. The measurements show a dependence on atomic number. While the
quasielastic-like scattering on carbon is compatible with predictions, the
trends exhibited by scattering on iron and lead favor a prediction with
intranuclear rescattering of hadrons accounted for by a conventional particle
cascade treatment. These measurements help discriminate between different
models of both initial state nucleons and final state interactions used in the
neutrino oscillation experiments
Reducing model bias in a deep learning classifier using domain adversarial neural networks in the MINERvA experiment
We present a simulation-based study using deep convolutional neural networks
(DCNNs) to identify neutrino interaction vertices in the MINERvA passive
targets region, and illustrate the application of domain adversarial neural
networks (DANNs) in this context. DANNs are designed to be trained in one
domain (simulated data) but tested in a second domain (physics data) and
utilize unlabeled data from the second domain so that during training only
features which are unable to discriminate between the domains are promoted.
MINERvA is a neutrino-nucleus scattering experiment using the NuMI beamline at
Fermilab. -dependent cross sections are an important part of the physics
program, and these measurements require vertex finding in complicated events.
To illustrate the impact of the DANN we used a modified set of simulation in
place of physics data during the training of the DANN and then used the label
of the modified simulation during the evaluation of the DANN. We find that deep
learning based methods offer significant advantages over our prior track-based
reconstruction for the task of vertex finding, and that DANNs are able to
improve the performance of deep networks by leveraging available unlabeled data
and by mitigating network performance degradation rooted in biases in the
physics models used for training.Comment: 41 page
The T2K ND280 Off-Axis Pi-Zero Detector
The Pi-Zero detector (P{\O}D) is one of the subdetectors that makes up the
off-axis near detector for the Tokai-to-Kamioka (T2K) long baseline neutrino
experiment. The primary goal for the P{\O}D is to measure the relevant cross
sections for neutrino interactions that generate pi-zero's, especially the
cross section for neutral current pi-zero interactions, which are one of the
dominant sources of background to the electron neutrino appearance signal in
T2K. The P{\O}D is composed of layers of plastic scintillator alternating with
water bags and brass sheets or lead sheets and is one of the first detectors to
use Multi-Pixel Photon Counters (MPPCs) on a large scale.Comment: 17 pages, submitted to NIM
Evaluation of thrombin generation in dogs administered clopidogrel
IntroductionThe antiplatelet effect of clopidogrel can vary between patients. A modified thromboelastography (TEG) protocol (TEG-Platelet Mapping assay® [TEG-PM]) can be used for clopidogrel monitoring but is not widely available. Thrombin generation (TG) assays could offer a novel alternative. The main objective of this pilot study was to assess TG assay variables (lag time, peak, endogenous thrombin potential [ETP]) in dogs before and after 7 days of clopidogrel administration and compare with TEG-PM variables (maximum amplitude [MA]-ADP and percentage (%) inhibition).MethodsSix healthy mix-breed dogs were enrolled in this pilot study. Blood samples for platelet count, TG assays, and TEG-PM were obtained at two time points, corresponding to baseline, and after 7 days of clopidogrel administration (mean 2.3 +/− 0.3 mg/kg PO q24 hours). Data were then compared with a Student’s t-test.ResultsThere was no significant change in TG assay variables performed on platelet poor plasma after 7 days of clopidogrel administration: lag time (Day 1: 1.8 +/− 0.2 min, Day 7: 1.8 +/− 0.2 min, p = 0.42); peak (Day 1: 76 +/− 7 nM, Day 7: 72 +/− 10 nM, p = 0.49); and ETP (Day 1: 399 +/− 27 nM*min, Day 7: 392 +/− 32 nM*min; p = 0.49). There were significant changes in TEG MA-ADP (Day 1: 19 +/− 8 mm, Day 7: 9 +/− 6 mm, p = 0.04) and % inhibition (Day 1: 58 +/− 27, Day 7: 99 +/− 0.3, p = 0.02).DiscussionClopidogrel administration did not lead to changes in TG assay variables performed on platelet poor plasma samples, despite concomitant changes in TEG-PM variables consistent with platelet inhibition. Based on this pilot study, thrombin generation performed on platelet poor plasma may not be a useful antiplatelet monitoring tool in dogs
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