868 research outputs found
Field dependence of electronic recoil signals in a dual-phase liquid xenon time projection chamber
We present measurements of light and charge signals in a dual-phase time
projection chamber at electric fields varying from 10 V/cm up to 500 V/cm and
at zero field using 511 keV gamma rays from a Na source. We determine
the drift velocity, electron lifetime, diffusion constant, and light and charge
yields at 511 keV as a function of the electric field. In addition, we fit the
scintillation pulse shape to an effective exponential model, showing a decay
time of 43.5 ns at low field that decreases to 25 ns at high fields.Comment: 14 pages, 8 figure
Vertex reconstruction algorithms in the PHOBOS experiment at RHIC
The PHOBOS experiment at the Relativistic Heavy Ion Collider (RHIC) at
Brookhaven National Laboratory is studying interactions of heavy nuclei at the
largest energies available in the laboratory. The high multiplicity of
particles created in heavy ion collisions makes precise vertex reconstruction
possible using information from a spectrometer and a specialized vertex
detector with relatively small acceptances. For lower multiplicity events, a
large acceptance, single layer multiplicity detector is used and special
algorithms are developed to reconstruct the vertex, resulting in high
efficiency at the expense of poorer resolution. The algorithms used in the
PHOBOS experiment and their performance are presented.Comment: presented at the Workshop on Tracking In high Multiplicity
Environments, TIME0
Neutrino CP violating parameters from nontrivial quark-lepton correlation: a S3xGUT model
We investigate the prediction on the lepton phases in theories with a non
trivial correlation between quark (CKM) and lepton (PMNS) mixing matrices. We
show that the actual evidence, under the only assumption that the correlation
matrix product of and has a zero in the entry , gives
us a prediction for the three CP-violating invariants , , and . A
better determination of the lepton mixing angles will give a strong prediction
of the CP-violating invariants in the lepton sector. These will be tested in
the next generation experiments. To clarify how our prediction works, we show
how a model based on a Grand Unified Theory and the permutation flavor symmetry
predicts .Comment: 7 pages, 3 figures. V2: new figure adde
Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment
Monte Carlo Simulation Variance Reduction Techniques for Photon Transport in Liquid Xenon Detectors
Monte Carlo simulations are a crucial tool for the analysis and prediction of
various background components in liquid xenon (LXe) detectors. With improving
shielding in new experiments, the simulation of external backgrounds, such as
induced by gamma rays from detector materials, gets more computationally
expensive. We introduce and validate an accelerated Monte Carlo simulation
technique for photon transport in liquid xenon detectors. The method simulates
photon-induced interactions within a defined geometry and energy range with
high statistics while interactions outside of the region of interest are not
simulated directly but are taken into account by means of probability weights.
For a simulation of gamma induced backgrounds in an exemplary detector geometry
we achieve a three orders of magnitude acceleration compared to a standard
simulation of a current ton-scale LXe dark matter experiment
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