Papers

Recent Publications

Selected publication list is provided here in reverse chronological order.
Complete list of papers can be found here



Using Commercial Off-The-Shelf (COTS) Operational Amplifiers (OpAmps) and Complementary Metal-Oxide Semiconductor (CMOS) transistors, we present a demonstration of the Q-Pix front-end architecture, a novel readout solution for kiloton-scale Liquid Argon Time Projection Chamber (LArTPC) detectors. The Q-Pix scheme employs a Charge-Integrate/Reset process based on the Least Action principle, enabling pixel-scale self-triggering charge collection and processing, minimizing energy consumption, and maximizing data compression. We examine the architecture's sensitivity, linearity, noise, and other features at the circuit board level and draw comparisons to SPICE simulations. Furthermore, we highlight the resemblance between the Q-Pix front-end and Sigma-Delta modulator, emphasizing that digital data processing techniques for Sigma-Delta can be directly applied to Q-Pix, resulting in enhanced signal-to-noise performance. These insights will inform the development of Q-Pix front-end designs in integrated circuits (IC) and guide data collection and processing for future large-scale LArTPC detectors in neutrino physics and other high-energy physics experiments.

arXiv: 2311.09568 / Submitted to Nuclear Instruments and Methods in Physics Research

Demonstrating the Q-Pix front-end using discrete OpAmp and CMOS transistors


The search for neutrinoless double beta decay (0νββ) remains one of the most compelling experimental avenues for the discovery in the neutrino sector. Electroluminescent gas-phase time projection chambers are well suited to 0νββ searches due to their intrinsically precise energy resolution and topological event identification capabilities. Scalability to ton- and multi-ton masses requires readout of large-area electroluminescent regions with fine spatial resolution, low radiogenic backgrounds, and a scalable data acquisition system. This paper presents a detector prototype that records event topology in an electroluminescent xenon gas TPC via VUV image-intensified cameras. This enables an extendable readout of large tracking planes with commercial devices that reside almost entirely outside of the active medium.Following further development in intermediate scale demonstrators, this technique may represent a novel and enlargeable method for topological event imaging in 0νββ.

arXiv:2304.06091 / JINST 18 (2023) 08, P08006

NEXT-CRAB-0: A High Pressure Gaseous Xenon Time Projection Chamber with a Direct VUV Camera Based Readout


Detection of the vacuum ultraviolet (VUV) scintillation light produced by liquid noble elements is a central challenge in order to fully exploit the available timing, topological, and calorimetric information in detectors leveraging these media. In this paper, we characterize a novel, windowless amorphous selenium based photodetector with direct sensitivity to VUV light. We present here the manufacturing and experimental setup used to operate this detector at low transport electric fields (2.7-5.2 V/μm) and across a wide range of temperatures (77K-290K). This work shows that the first proof-of-principle device windowless amorphous selenium is robust under cryogenic conditions, responsive to VUV light at cryogenic temperatures, and preserves argon purity. These findings motivate a continued exploration of amorphous selenium devices for simultaneous detection of scintillation light and ionization charge in noble element detectors

arXiv:2207.11127 / JINST 18 (2023) 01, P01029

Development of a novel, windowless, amorphous selenium based photodetector for use in liquid noble detectors


The detection of neutrinos from core-collapse supernovae may reveal important process features as well as neutrino properties. The detection of supernova neutrinos is one of the main science drivers for future kiloton-scale neutrino detectors based on liquid argon. Here we show that for such detectors the intrinsically 3D readout in Q-Pix offers numerous advantages relative to a wire-based readout, such as higher reconstruction efficiency, lower energy threshold, considerably lower data rates, and potential pointing information.

arXiv:2203.12109 / Phys. Rev. D 106, 032011 (2022)

Enhanced Low-Energy Supernova Burst Detection in Large Liquid Argon Time Projection Chambers Enabled by Q-Pix


In this white paper, we outline some of the scientific opportunities and challenges related to detection and reconstruction of low-energy (less than 100 MeV) signatures in liquid argon time-projection chamber (LArTPC) detectors. Key takeaways are summarized as follows. 1) LArTPCs have unique sensitivity to a range of physics and astrophysics signatures via detection of event features at and below the few tens of MeV range. 2) Low-energy signatures are an integral part of GeV-scale accelerator neutrino interaction final states, and their reconstruction can enhance the oscillation physics sensitivities of LArTPC experiments. 3) BSM signals from accelerator and natural sources also generate diverse signatures in the low-energy range, and reconstruction of these signatures can increase the breadth of BSM scenarios accessible in LArTPC-based searches. 4) Neutrino interaction cross sections and other nuclear physics processes in argon relevant to sub-hundred-MeV LArTPC signatures are poorly understood. Improved theory and experimental measurements are needed. Pion decay-at-rest sources and charged particle and neutron test beams are ideal facilities for experimentally improving this understanding. 5) There are specific calibration needs in the low-energy range, as well as specific needs for control and understanding of radiological and cosmogenic backgrounds. 6) Novel ideas for future LArTPC technology that enhance low-energy capabilities should be explored. These include novel charge enhancement and readout systems, enhanced photon detection, low radioactivity argon, and xenon doping. 7) Low-energy signatures, whether steady-state or part of a supernova burst or larger GeV-scale event topology, have specific triggering, DAQ and reconstruction requirements that must be addressed outside the scope of conventional GeV-scale data collection and analysis pathways.

arXiv:2203.00740 / Journal of Physics G: Nuclear and Particle Physics

Low-Energy Physics in Neutrino LArTPCs


This paper describes the development of a pulsed light source using the discharge from an electrode in a medium of various noble gases. This source can be used to aid in the characterization and testing of new vacuum-ultraviolet (VUV) sensitive light detection devices. The source includes a novel spark driver circuit, a spark chamber into which different noble gases can be introduced, and an optical attenuation cell capable of being filled with different gases to allow for the attenuation of the pulsed light down to single photon levels. We describe the construction, calibration, and characterization of this device deployed at a dedicated light detection test stand at Oak Ridge National Laboratory.

arXiv:2111.06448 / Review of Scientific Instruments 93, 053103

Development of a Pulsed VUV Light Source With Adjustable Intensity


We present the first measurement of the negative pion total hadronic cross section on argon, which we performed at the Liquid Argon In A Testbeam (LArIAT) experiment. All hadronic reaction channels, as well as hadronic elastic interactions with scattering angle greater than 5~degrees are included. The pions have a kinetic energies in the range 100-700~MeV and are produced by a beam of charged particles impinging on a solid target at the Fermilab Test Beam Facility. LArIAT employs a 0.24~ton active mass Liquid Argon Time Projection Chamber (LArTPC) to measure the pion hadronic interactions. For this measurement, LArIAT has developed the ``thin slice method", a new technique to measure cross sections with LArTPCs. While generally higher than the prediction, our measurement of the (π−,Ar) total hadronic cross section is in agreement with the prediction of the Geant4 model when considering a model uncertainty of ∼5.1\%

arXiv:2108.00040 / Phys. Rev. D 106, 052009

Measurement of the (π−, Ar) total hadronic cross section at the LArIAT experiment


Liquid argon is commonly used as a detector medium for neutrino physics and dark matter experiments in part due to its copious scintillation light production in response to its excitation and ionization by charged particle interactions. As argon scintillation appears in the vacuum ultraviolet (VUV) regime and is difficult to detect, wavelength-shifting materials are typically used to convert VUV light to visible wavelengths more easily detectable by conventional means. In this work, we examine the wavelength-shifting and optical properties of poly(ethylene naphthalate) (PEN), a recently proposed alternative to tetraphenyl butadiene (TPB), the most widely-used wavelength-shifter in argon-based experiments. In a custom cryostat system with well-demonstrated geometric and response stability, we use 128 nm argon scintillation light to examine various PEN-including reflective samples' light-producing capabilities, and study the stability of PEN when immersed in liquid argon. The best-performing PEN-including test reflector was found to produce 34% as much visible light as a TPB-including reference sample, with widely varying levels of light production between different PEN-including test reflectors. Plausible origins for these variations, including differences in optical properties and molecular orientation, are then identified using additional measurements. Unlike TPB-coated samples, PEN-coated samples did not produce long-timescale light collection increases associated with solvation or suspension of wavelength-shifting material in bulk liquid argon.

arXiv:2103.03232 / JINST 16 P07017

Wavelength-shifting performance of polyethylene naphthalate films in a liquid argon environment


Selenium is a crucial earth-abundant and non-toxic semiconductor with a wide range of applications across the semiconductor industries. Selenium has drawn attention from scientific communities for its wide range of applicability: from photovoltaics to imaging devices. Its usage as a photosensitive material largely involves the synthesis of the amorphous phase (a-Se) via various experimental techniques. However, the ground state crystalline phase of this material, known as the trigonal selenium (t-Se), is not extensively studied for its optimum electronic and optical properties. In this work, we present density functional theory (DFT) based systematic studies on the ultra-thin (1010) surface slabs of t-Se. We report the surface energies, work function, electronic and optical properties as a function of number of layers for (1010) surface slabs to access its suitability for applications as a photosensitive material.

arXiv:2104.14455 / Langmuir 2022, 38, 28, 8485–8494

First principles studies of the surface and opto-electronic properties of ultra-thin t-Se


In this paper we explore the potential improvements in neutrino event reconstruction that a 3D pixelated readout could offer over a 2D projective wire readout for liquid argon time projection chambers. We simulate and study events in two generic, idealized detector configurations for these two designs, classifying events in each sample with deep convolutional neural networks to compare the best 2D results to the best 3D results. In almost all cases we find that the 3D readout provides better reconstruction efficiency and purity than the 2D projective wire readout, with the advantages of 3D being particularly evident in more complex topologies, such as electron neutrino charged current events. We conclude that the use of a 3D pixelated detector could significantly enhance the reach and impact of future liquid argon TPC experiments physics program, such as DUNE.

arXiv:1912.10133 / JINST 15 P04009

Enhancing Neutrino Event Reconstruction with Pixel-Based 3D Readout for Liquid Argon Time Projection Chambers


The LArIAT liquid argon time projection chamber, placed in a tertiary beam of charged particles at the Fermilab Test Beam Facility, has collected large samples of pions, muons, electrons, protons, and kaons in the momentum range 300-1400 MeV/c. This paper describes the main aspects of the detector and beamline, and also reports on calibrations performed for the detector and beamline components.

arXiv:1911.10379 / JINST 15 P04026

The Liquid Argon In A Testbeam (LArIAT) Experiment


A search for millicharged particles, a simple extension of the standard model, has been performed with the ArgoNeuT detector exposed to the Neutrinos at the Main Injector beam at Fermilab. The ArgoNeuT Liquid Argon Time Projection Chamber detector enables a search for millicharged particles through the detection of visible electron recoils. We search for an event signature with two soft hits (MeV-scale energy depositions) aligned with the upstream target. For an exposure of the detector of 1.0 × 1020 protons on target, one candidate event has been observed, compatible with the expected background. This search is sensitive to millicharged particles with charges between 10−3e and 10−1e and with masses in the range from 0.1 GeV to 3 GeV. This measurement provides leading constraints on millicharged particles in this large unexplored parameter space region.

arXiv:1911.07996 / Phys. Rev. Lett. 124, 131801 (2020)

Improved Limits on Millicharged Particles Using the ArgoNeuT Experiment at Fermilab


We present upper limits on the production of heavy neutral leptons (HNLs) decaying to μπ pairs using data collected with the MicroBooNE liquid-argon time projection chamber (TPC) operating at Fermilab. This search is the first of its kind performed in a liquid-argon TPC. We use data collected in 2017 and 2018 corresponding to an exposure of 2.0×1020 protons on target from the Fermilab Booster Neutrino Beam, which produces mainly muon neutrinos with an average energy of ≈800 MeV. HNLs with higher mass are expected to have a longer time-of-flight to the liquid-argon TPC than Standard Model neutrinos. The data are therefore recorded with a dedicated trigger configured to detect HNL decays that occur after the neutrino spill reaches the detector. We set upper limits at the 90% confidence level on the element |4|2 of the extended PMNS mixing matrix in the range |4|2<(6.6-0.9)×10−7 for Dirac HNLs and |4|2<(4.7-0.7)×10−7 for Majorana HNLs, assuming HNL masses between 260 and 385 MeV and |Ue4|2=|4|2=0.

arXiv:1911.10545 / Phys. Rev. D 101, 052001 (2020)

Search for heavy neutral leptons decaying into muon-pion pairs in the MicroBooNE detector


Precise calorimetric reconstruction of 5-50 MeV electrons in liquid argon time projection chambers (LArTPCs) will enable the study of astrophysical neutrinos in DUNE and could enhance the physics reach of oscillation analyses. Liquid argon scintillation light has the potential to improve energy reconstruction for low-energy electrons over charge-based measurements alone. Here we demonstrate light-augmented calorimetry for low-energy electrons in a single-phase LArTPC using a sample of Michel electrons from decays of stopping cosmic muons in the LArIAT experiment at Fermilab. Michel electron energy spectra are reconstructed using both a traditional charge-based approach as well as a more holistic approach that incorporates both charge and light. A maximum-likelihood fitter, using LArIAT's well-tuned simulation, is developed for combining these quantities to achieve optimal energy resolution. A sample of isolated electrons is simulated to better determine the energy resolution expected for astrophysical electron-neutrino charged-current interaction final states. In LArIAT, which has very low wire noise and an average light yield of 18 pe/MeV, an energy resolution of σ/E≃9.3%/E−−√⊕1.3% is achieved. Samples are then generated with varying wire noise levels and light yields to gauge the impact of light-augmented calorimetry in larger LArTPCs. At a charge-readout signal-to-noise of S/N ≃ 30, for example, the energy resolution for electrons below 40 MeV is improved by ≈ 10%, ≈ 20%, and ≈ 40% over charge-only calorimetry for average light yields of 10 pe/MeV, 20 pe/MeV, and 100 pe/MeV, respectively.

arXiv: 1909.07920 / Phys. Rev. D 101, 012010 (2020)

Calorimetry for low-energy electrons using charge and light in liquid argon


With the discovery of non-zero value of θ13 mixing angle, the next generation of long-baseline neutrino (LBN) experiments offers the possibility of obtaining statistically significant samples of muon and electron neutrinos and anti-neutrinos with large oscillation effects. In this document we intend to highlight the importance of Near Detector facilities in LBN experiments to both constrain the systematic uncertainties affecting oscillation analyses but also to perform, thanks to their close location, measurements of broad benefit for LBN physics goals. A strong European contribution to these efforts is possible.

arXiv:1901.04346 /

Research and Development for Near Detector Systems Towards Long Term Evolution of Ultra-precise Long-baseline Neutrino Experiments


We report the first measurement of the flux-integrated cross section of νμ charged-current single π0 production on argon. This measurement is performed with the MicroBooNE detector, an 85 ton active mass liquid argon time projection chamber exposed to the Booster Neutrino Beam at Fermilab. This result on argon is compared to past measurements on lighter nuclei to investigate the scaling assumptions used in models of the production and transport of pions in neutrino-nucleus scattering. The techniques used are an important demonstration of the successful reconstruction and analysis of neutrino interactions producing electromagnetic final states using a liquid argon time projection chamber operating at the earth's surface.

arXiv:1811.02700 / Phys. Rev. D 99, 091102(R)

First Measurement of νμ Charged-Current π0 Production on Argon with a LArTPC


Demonstration of MeV-Scale Physics in Liquid Argon Time Projection Chambers Using ArgoNeuT


MeV-scale energy depositions by low-energy photons produced in neutrino-argon interactions have been identified and reconstructed in ArgoNeuT liquid argon time projection chamber (LArTPC) data. ArgoNeuT data collected on the NuMI beam at Fermilab were analyzed to select isolated low-energy depositions in the TPC volume. The total number, reconstructed energies and positions of these depositions have been compared to those from simulations of neutrino-argon interactions using the FLUKA Monte Carlo generator. Measured features are consistent with energy depositions from photons produced by de-excitation of the neutrino's target nucleus and by inelastic scattering of primary neutrons produced by neutrino-argon interactions. This study represents a successful reconstruction of physics at the MeV-scale in a LArTPC, a capability of crucial importance for detection and reconstruction of supernova and solar neutrino interactions in future large LArTPCs.

arXiv:1810.06502 / Phys. Rev. D 99, 012002



First measurement of the cross section for νμ and ν¯μ induced single charged pion production on argon using ArgoNeuT

We report on the first cross section measurement of charged-current single charged pion production by neutrinos and antineutrinos on argon. This analysis was performed using the ArgoNeuT detector exposed to the NuMI beam at Fermilab. The measurements are presented as functions of muon momentum, muon angle, pion angle, and angle between muon and pion. The flux-averaged cross sections are measured to be 2.7±0.5(stat)±0.5(syst)×10−37cm2/Ar for neutrinos at a mean energy of 9.6 GeV and 8.4±0.9(stat)+1.0−0.8(syst)×10−38cm2/Ar for antineutrinos at a mean energy of 3.6 GeV with the charged pion momentum above 100 MeV/c. The results are compared with several model predictions.

arXiv:1804.10294 / Phys. Rev. D 98, 052002


Tetraphenyl Butadiene Emanation and Bulk Fluorescence from Wavelength Shifting Coatings in Liquid Argon

We study the stability of three types of popularly employed TPB coatings under immersion in liquid argon. TPB emanation from each coating is quantified by fluorescence assay of molecular seive filter material after a prolonged soak time. Two of the coatings are shown to emanate a detectable concentration of TPB into argon over a 24 hour period, which corresponds to tens of parts per billion in argon by mass. In an independent setup, the dissolved or suspended TPB is shown to produce a wavelength shifting effect in the argon bulk which has at least two long, characteristic time constants of 0.95±0.05~ms and 17.8± 2.0 ms. Interpretations of these results and implications for present and future liquid argon time projection chamber experiments are discussed.

arXiv:1804.00011 / JINST 14 P02021


First Demonstration of a Pixelated Charge Readout for Single-Phase Liquid Argon Time Projection Chambers

Liquid Argon Time Projection Chambers (LArTPCs) have been selected for the future long-baseline Deep Underground Neutrino Experiment (DUNE). To allow LArTPCs to operate in the high-multiplicity near detector environment of DUNE, a new charge readout technology is required. Traditional charge readout technologies introduce intrinsic ambiguities, combined with a slow detector response, these ambiguities have limited the performance of LArTPCs, until now. Here, we present a novel pixelated charge readout that enables the full 3D tracking capabilities of LArTPCs. We characterise the signal to noise ratio of charge readout chain, to be about 14, and demonstrate track reconstruction on 3D space points produced by the pixel readout. This pixelated charge readout makes LArTPCs a viable option for the DUNE near detector complex.

arXiv:1801.08884 / Instruments 20204(1), 9


A New Light Higgs Boson and Short-Baseline Neutrino Anomalies

The low-energy excesses observed by the MiniBooNE experiment have, to date, defied a convincing explanation under the standard model even with accommodation for non-zero neutrino mass. In this paper we explore a new oscillation mechanism to explain these anomalies, invoking a light neutrinophilic Higgs boson, conceived to induce a low Dirac neutrino mass in accord with experimental limits. Beam neutrinos forward-scattering off of a locally over-dense relic neutrino background give rise to a novel matter-effect with an energy-specific resonance. An enhanced oscillation around this resonance peak produces flavor transitions which are highly consistent with the MiniBooNE neutrino and antineutrino-mode data sets. The model provides substantially improved χ2 values beyond either the no-oscillation hypothesis or the more commonly explored 3+1 sterile neutrino hypothesis. This mechanism would introduce distinctive signatures at each baseline in the upcoming SBN program at Fermilab, presenting opportunities for further exploration.

arXiv:1712.08019 / Phys. Rev. D 97, 075021


ProtoDUNE-SP is the single-phase DUNE Far Detector prototype that is under construction and will be operated at the CERN Neutrino Platform (NP) starting in 2018. ProtoDUNE-SP, a crucial part of the DUNE effort towards the construction of the first DUNE 10-kt fiducial mass far detector module (17 kt total LAr mass), is a significant experiment in its own right. With a total liquid argon (LAr) mass of 0.77 kt, it represents the largest monolithic single-phase LArTPC detector to be built to date. It's technical design is given in this report.

arXiv:1706.07081 /

The Single-Phase ProtoDUNE Technical Design Report


This paper describes the design and construction of the MicroBooNE liquid argon time projection chamber and associated systems. MicroBooNE is the first phase of the Short Baseline Neutrino program, located at Fermilab, and will utilize the capabilities of liquid argon detectors to examine a rich assortment of physics topics. In this document details of design specifications, assembly procedures, and acceptance tests are reported.

arXiv:1612.05824 / JINST 12 P02017

Design and Construction of the MicroBooNE Detector


The capabilities of liquid argon time projection chambers (LArTPCs) to reconstruct the spatial and calorimetric information of neutrino events have made them the detectors of choice in a number of experiments, specifically those looking to observe electron neutrino (νe) appearance. The LArTPC promises excellent background rejection capabilities, especially in this "golden" channel for both short and long baseline neutrino oscillation experiments. We present the first experimental observation of electron neutrinos and anti-neutrinos in the ArgoNeut LArTPC, in the energy range relevant to DUNE and the Fermilab Short Baseline Neutrino Program. We have selected 37 electron candidate events and 274 gamma candidate events, and measured an 80\% purity of electrons based on a topological selection. Additionally, we present a of separation of electrons from gammas using calorimetric energy deposition, demonstrating further separation of electrons from background gammas.

arXiv:1610.04102 / Phys. Rev. D 95, 072005

First Observation of Low Energy Electron Neutrinos in a Liquid Argon Time Projection Chamber



In this paper we describe how the readout planes for the MicroBooNE Time Projection Chamber were constructed, assembled and installed. We present the individual wire preparation using semi-automatic winding machines and the assembly of wire carrier boards. The details of the wire installation on the detector frame and the tensioning of the wires are given. A strict quality assurance plan ensured the integrity of the readout planes. The different tests performed at all stages of construction and installation provided crucial information to achieve the successful realisation of the MicroBooNE wire planes.

arXiv:1609.06169 / JINST 12 T03003

Construction and Assembly of the Wire Planes for the MicroBooNE Time Projection Chamber


The ArgoNeuT collaboration reports the first measurement of neutral current π0 production in νμ-argon and ν¯μ-argon scattering. This measurement was performed using the ArgoNeuT liquid argon time projection chamber deployed at Fermilab's NuMI neutrino beam with an exposure corresponding to 1.2×1020 protons-on-target from the Fermilab Main Injector and a mean energy for νμ of 9.6~GeV and for ν¯μ of 3.6~GeV. We compare the measured cross section and kinematic distributions to predictions from the GENIE and NuWro neutrino interaction event generators.

arXiv:1511.00941 / Phys. Rev. D 96, 012006

Measurement of νμ and ν¯μ Neutral Current π0→γγ Production in the ArgoNeuT Detector


We report on the first cross section measurements for charged current coherent pion production by neutrinos and antineutrinos on argon. These measurements are performed using the ArgoNeuT detector exposed to the NuMI beam at Fermilab. The cross sections are measured to be 2.6+1.2−1.0(stat)+0.3−0.4(syst)×10−38cm2/Ar for neutrinos at a mean energy of 9.6 GeV and 5.5+2.6−2.1(stat)+0.6−0.7(syst)×10−39cm2/Ar for antineutrinos at a mean energy of 3.6 GeV.

arXiv:1408.0598 / Phys. Rev. Lett. 113, 261801

First Measurement of Neutrino and Antineutrino Coherent Charged Pion Production on Argon


Liquid Argon Time Projection Chambers (LArTPCs) are ideal detectors for precision neutrino physics. These detectors, when located deep underground, can also be used for measurements of proton decay, and astrophysical neutrinos. The technology must be completely developed, up to very large mass scales, and fully mastered to construct and operate these detectors for this physics program. As part of an integrated plan of developing these detectors, accurate measurements in LArTPC of known particle species in the relevant energy ranges are now deemed as necessary. The LArIAT program aims to directly achieve these goals by deploying LArTPC detectors in a dedicated calibration test beam line at Fermilab. The set of measurements envisaged here are significant for both the short-baseline (SBN) and long-baseline (LBN) neutrino oscillation programs in the US, starting with MicroBooNE in the near term and with the adjoint near and far liquid argon detectors in the Booster beam line at Fermilab envisioned in the mid-term, and moving towards deep underground physics such as with the long-baseline neutrino facility (LBNF) in the longer term.

arXiv:1406.5560

LArIAT: Liquid Argon In A Testbeam



In this paper we demonstrate the capability of high voltage varistors and gas discharge tube arrestors for use as surge protection devices in liquid argon time projection chamber detectors. The insulating and clamping behavior of each type of device is characterized in air (room temperature), and liquid argon (90~K), and their robustness under high voltage and high energy surges in cryogenic conditions is verified. The protection of vulnerable components in liquid argon during a 150 kV high voltage discharge is also demonstrated. Each device is tested for argon contamination and light emission effects, and both are constrained to levels where no significant impact upon liquid argon time projection chamber functionality is expected. Both devices investigated are shown to be suitable for HV surge protection applications in cryogenic detectors.

arXiv:1406.5216 / JINST 9 P09002

Testing of High Voltage Surge Protection Devices for Use in Liquid Argon TPC Detectors


Short range nucleon-nucleon correlations in nuclei (NN SRC) carry important information on nuclear structure and dynamics. NN SRC have been extensively probed through two-nucleon knock- out reactions in both pion and electron scattering experiments. We report here on the detection of two-nucleon knock-out events from neutrino interactions and discuss their topological features as possibly involving NN SRC content in the target argon nuclei. The ArgoNeuT detector in the Main Injector neutrino beam at Fermilab has recorded a sample of 30 fully reconstructed charged current events where the leading muon is accompanied by a pair of protons at the interaction vertex, 19 of which have both protons above the Fermi momentum of the Ar nucleus. Out of these 19 events, four are found with the two protons in a strictly back-to-back high momenta configuration directly observed in the final state and can be associated to nucleon Resonance pionless mechanisms involving a pre-existing short range correlated np pair in the nucleus. Another fraction (four events) of the remaining 15 events have a reconstructed back-to-back configuration of a np pair in the initial state, a signature compatible with one-body Quasi Elastic interaction on a neutron in a SRC pair. The detection of these two subsamples of the collected (mu- + 2p) events suggests that mechanisms directly involving nucleon-nucleon SRC pairs in the nucleus are active and can be efficiently explored in neutrino-argon interactions with the LAr TPC technology.

arXiv:1405.4261 / Phys. Rev. D 90, 012008

The detection of back-to-back proton pairs in Charged-Current neutrino interactions with the ArgoNeuT detector in the NuMI low energy beam line


From April to July 2013 the Snowmass Young Physicists (SYP) administered an online survey collecting the opinions and concerns of the High Energy Physics (HEP) community. The aim of this survey is to provide input into the long term planning meeting known as the Community Summer Study (CSS), or Snowmass on the Mississippi. In total, 1112 respondents took part in the survey including 74 people who had received their training within HEP and have since left for non-academic jobs. This paper presents a summary of the survey results including demographic, career outlook, planned experiments and non-academic career path information collected.

arXiv:1307.8080

Snowmass 2013 Young Physicists Science and Career Survey Report