Abstract
Experimental data shows that both ionization charge and scintillation light in LAr depend on the deposited energy density (d
E
/d
x
) and electric field (
E
). Moreover, free ionization ...charge and scintillation light are anticorrelated, complementary at a given (d
E
/d
x
,
E
) pair. We present LArQL, a phenomenological model that provides the anticorrelation between light and charge and its dependence on the deposited energy as well as on the electric field applied. It modifies the Birks’ charge model considering the contribution from the escape electrons at null and low electric fields, and reconciles with Birks’ model prediction at higher fields. Deviations from current Birks’ model are observed for LArTPCs operating at low
E
and for heavily ionizing particles. The LArQL model presents a satisfactory description at d
E
/d
x
and field ranges for interacting particles in LArTPCs and fits well the available data. Improvements via data sets compilation and “global” fits are also interesting features of the model.
ProtoDUNE Single Phase at CERN is the large-scale prototype for the far detector of the future DUNE experiment. ProtoDUNE is in stable operation since Oct. 2018 at the CERN Neutrino Platform. Test ...beam data in the energy range of sub-GeV to a few GeV were collected in fall 2018 providing a set of key measurements. Particles (electrons, protons, pions, muons and kaons) are identified combining information from a set of beam-line detectors (Time of Flight, Cherenkov) and TPC reconstruction. Three different technologies are implemented in the protoDUNE photon detector system (PDS). Results from the response of ARAPUCA, one of the PDS components, are presented providing first calorimetric energy measurements of beam events from liquid argon scintillation light signals.
The Liquid Argon Time Projection Chambers (LArTPCs) are a choice for the next generation of large neutrino detectors due to their optimal performance in particle tracking and calorimetry. The ...detection of Argon scintillation light plays a crucial role in the event reconstruction as well as the time reference for non-beam physics such as supernovae neutrino detection and baryon number violation studies. In this contribution, we present the current R&D work on the ARAPUCA (Argon R&D Advanced Program at UNICAMP), a light trap device to enhance Ar scintillation light collection and thus the overall performance of LArTPCs. The ARAPUCA working principle is based on a suitable combination of dichroic filters and wavelength shifters to achieve a high efficiency in light collection. We discuss the operational principles, the last results of laboratory tests and the application of the ARAPUCA as the alternative photon detection system in the protoDUNE detector.
In the Fall of 2017, two photon detector designs for the Deep Underground Neutrino Experiment (DUNE) Far Detector were installed and tested in the TallBo liquid argon (LAr) cryostat at the Proton ...Assembly (PAB) facility, Fermilab. The designs include two light bars developed at Indiana University and a photon detector based on the ARAPUCA light trap engineered by Colorado State University and Fermilab. The performance of these devices is determined by analyzing 8 weeks of cosmic ray data. The current paper focuses solely on the ARAPUCA device as the performance of the light bars will be reported separately. The paper briefly describes the ARAPUCA concept, the TallBo setup, and focuses on data analysis and results.
We present a novel methodology to search for intranuclearneutron-antineutron transition (n⟶n̅) followed by n̅-nucleon annihilation within an 40Ar nucleus, usingthe MicroBooNE liquid argon time ...projection chamber (LArTPC)detector. A discovery of n⟶n̅ transition or a newbest limit on the lifetime of this process would either constitutephysics beyond the Standard Model or greatly constrain theories ofbaryogenesis, respectively. The approach presented in this papermakes use of deep learning methods to select n⟶n̅ events based on their unique features and differentiate them fromcosmogenic backgrounds. The achieved signal and backgroundefficiencies are (70.22 ± 6.04)% and (0.0020 ± 0.0003)%,respectively. A demonstration of a search is performed with a dataset corresponding to an exposure of3.32 ×1026 neutron-years, and where the background rateis constrained through direct measurement, assuming the presence ofa negligible signal. With this approach, no excess of events overthe background prediction is observed, setting a demonstrative lowerbound on the n⟶n̅ lifetime in 40Ar ofτm ≳ 1.1×1026 years, and on the freen⟶n̅ transition time ofτn⟶n̅ ≳ 2.6×105 s,each at the 90% confidence level. This analysis represents afirst-ever proof-of-principle demonstration of the ability to searchfor this rare process in LArTPCs with high efficiency and lowbackground.
Experimental data shows that both ionization charge and scintillation light in LAr depend on the deposited energy density (\(dE/dx\)) and electric field (\(\mathcal{E}\)). Moreover, free ionization ...charge and scintillation light are anticorrelated, complementary at a given (\(dE/dx\), \(\mathcal{E}\)) pair. We present LArQL, a phenomenological model that provides the anticorrelation between light and charge and its dependence on the deposited energy as well as on the electric field applied. It modifies the Birks' charge model considering the contribution from the escape electrons at null and low electric fields, and reconciles with Birks' model prediction at higher fields. Deviations from current Birks' model are observed for LArTPCs operating at low \(\mathcal{E}\) and for heavily ionizing particles. The LArQL model presents a satisfactory description at \(dE/dx\) and field ranges for interacting particles in LArTPCs and fits well the available data. Improvements via data sets compilation and global fits are also interesting features of the model.
Power-over-Fiber (PoF) technology has been used extensively in settings where
high voltages require isolation from ground. In a novel application of PoF,
power is provided to photon detector modules ...located on a surface at $\sim$ 300
kV with respect to ground in the planned DUNE experiment. In cryogenic
environments, PoF offers a reliable means of power transmission, leveraging
optical fibers to transfer power with minimal system degradation. PoF
technology excels in maintaining low noise levels when delivering power to
sensitive electronic systems operating in extreme temperatures and high voltage
environments. This paper presents the R$\&$D effort of PoF in extreme
conditions and underscores its capacity to revolutionize power delivery and
management in critical applications, offering a dependable solution with low
noise, optimal efficiency, and superior isolation.
We report the first double-differential cross section measurement of
neutral-current neutral pion (NC$\pi^0$) production in neutrino-argon
scattering, as well as single-differential measurements of ...the same channel in
terms of final states with and without protons. The kinematic variables of
interest for these measurements are the $\pi^0$ momentum and the $\pi^0$
scattering angle with respect to the neutrino beam. A total of 4971 candidate
NC$\pi^0$ events fully-contained within the MicroBooNE detector are selected
using data collected at a mean neutrino energy of $\sim 0.8$ GeV from
$6.4\times10^{20}$ protons on target from the Booster Neutrino Beam at the
Fermi National Accelerator Laboratory. After extensive data-driven model
validation to ensure unbiased unfolding, the Wiener-SVD method is used to
extract nominal flux-averaged cross sections. The results are compared to
predictions from commonly used neutrino event generators, which tend to
overpredict the measured NC$\pi^0$ cross section, especially in the 0.2-0.5
GeV/c $\pi^0$ momentum range, at forward scattering angles, and when at least
one proton is present in the final state. These measurements show sensitivity
to a variety of features that complicate the description of NC$\pi^0$
production including the form factors describing the elementary neutrino
interaction and the final state interactions of the outgoing particles in the
residual argon nucleus. This data will help improve the modeling of NC$\pi^0$
production, which represents a major background in measurements of
charge-parity violation in the neutrino sector and in searches for new physics
beyond the Standard Model.
Phys. Rev. D 110, 013006 (2024) A detailed understanding of inclusive muon neutrino charged-current
interactions on argon is crucial to the study of neutrino oscillations in
current and future ...experiments using liquid argon time projection chambers. To
that end, we report a comprehensive set of differential cross section
measurements for this channel that simultaneously probe the leptonic and
hadronic systems by dividing the channel into final states with and without
protons. Measurements of the proton kinematics and proton multiplicity of the
final state are also presented. For these measurements, we utilize data
collected with the MicroBooNE detector from 6.4$\times10^{20}$ protons on
target from the Fermilab Booster Neutrino Beam at a mean neutrino energy of
approximately 0.8 GeV. We present in detail the cross section extraction
procedure, including the unfolding, and model validation that uses data to
model comparisons and the conditional constraint formalism to detect
mismodeling that may introduce biases to extracted cross sections that are
larger than their uncertainties. The validation exposes insufficiencies in the
overall model, motivating the inclusion of an additional data-driven
reweighting systematic to ensure the accuracy of the unfolding. The extracted
results are compared to a number of event generators and their performance is
discussed with a focus on the regions of phase-space that indicate the greatest
need for modeling improvements.
Phys. Rev. Lett. 132, 151801 Published 10 April 2024 We present a measurement of $\eta$ production from neutrino interactions on
argon with the MicroBooNE detector. The modeling of resonant neutrino
...interactions on argon is a critical aspect of the neutrino oscillation physics
program being carried out by the DUNE and Short Baseline Neutrino programs.
$\eta$ production in neutrino interactions provides a powerful new probe of
resonant interactions, complementary to pion channels, and is particularly
suited to the study of higher-order resonances beyond the $\Delta(1232)$. We
measure a flux-integrated cross section for neutrino-induced $\eta$ production
on argon of $3.22 \pm 0.84 \; \textrm{(stat.)} \pm 0.86 \; \textrm{(syst.)}$
$10^{-41}{\textrm{cm}}^{2}$/nucleon. By demonstrating the successful
reconstruction of the two photons resulting from $\eta$ production, this
analysis enables a novel calibration technique for electromagnetic showers in
GeV accelerator neutrino experiments.
PDF