195 research outputs found
Signal identification with Kalman Filter towards background-free neutrinoless double beta decay searches in gaseous detectors
Particle tracks and differential energy loss measured in high pressure
gaseous detectors can be exploited for event identification in neutrinoless
double beta decay~() searches. We develop a new method based
on Kalman Filter in a Bayesian formalism (KFB) to reconstruct meandering tracks
of MeV-scale electrons. With simulation data, we compare the signal and
background discrimination power of the KFB method assuming different detector
granularities and energy resolutions. Typical background from Th and
U decay chains can be suppressed by another order of magnitude than
that in published literatures, approaching the background-free regime. For the
proposed PandaX-III experiment, the search half-life
sensitivity at the 90\% confidence level would reach ~yr
with 5-year live time, a factor of 2.7 improvement over the initial design
target
Decker: Double Check with Heterogeneous Knowledge for Commonsense Fact Verification
Commonsense fact verification, as a challenging branch of commonsense
question-answering (QA), aims to verify through facts whether a given
commonsense claim is correct or not. Answering commonsense questions
necessitates a combination of knowledge from various levels. However, existing
studies primarily rest on grasping either unstructured evidence or potential
reasoning paths from structured knowledge bases, yet failing to exploit the
benefits of heterogeneous knowledge simultaneously. In light of this, we
propose Decker, a commonsense fact verification model that is capable of
bridging heterogeneous knowledge by uncovering latent relationships between
structured and unstructured knowledge. Experimental results on two commonsense
fact verification benchmark datasets, CSQA2.0 and CREAK demonstrate the
effectiveness of our Decker and further analysis verifies its capability to
seize more precious information through reasoning.Comment: 12 pages, 4 figure
Helium identification with LHCb
International audienceThe identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using collision data at recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of . A total of around helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately with a corresponding background rejection rate of up to . These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei
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