22 research outputs found
Reconstruction of the event vertex in the PandaX-III experiment with convolution neural network
The tracks left by charged particles in a gaseous time projection
chamber~(TPC) incorporate important information about the interaction process
and drift of electrons in gas. The electron diffusion information carried by
the tracks is an effective signature to reconstruct , the vertex position
in drift direction at which the event takes place. In this paper, we propose to
reconstruct with convolution neural network~(CNN) in the PandaX-III
experiment. A CNN model VGGZ0net is built and validated with Monte Carlo
simulation data. It gives with a 11~cm precision for the events above
2~MeV uniformly distributed along a drift distance of 120~cm, and then the
electron lifetime can be deduced. The energy resolution of detector is
significantly improved after the electron lifetime correction, i.e., from
10.1\% to 4.0\% FWHM at the Q-value of double beta decay of Xe for the
scenario with an electron lifetime of 6.5~ms. The CNN model is also
successfully applied to the experimental data of the PandaX-III prototype
detector for reconstruction
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