arXiv subjects

J. Asaadi

Publications and source records attributed to J. Asaadi.

At least 37 records · Page 2Linked to original sources

arXiv2026

Measurement of charged-current muon neutrino-argon interactions without pions in the final state using the MicroBooNE detector

We report a new measurement of flux-integrated differential cross sections for charged-current (CC) muon neutrino interactions with argon nuclei that produce no final-state pions ($ν_μ\mathrm{CC}0π$). These interactions are of particular importance as a topologically defined signal dominated by quasielasticlike interactions. This measurement was performed with the MicroBooNE liquid argon time projection chamber detector located at the Fermilab Booster Neutrino Beam and uses an exposure of $1.3\times10^{21}$ protons on target collected between 2015 and 2020. The results are presented in terms of single- and double-differential cross sections as a function of the final-state muon momentum and angle. The data are compared with widely used neutrino event generators. We find good agreement with the single-differential measurements, while only a subset of generators are also able to adequately describe the data in double-differential distributions. This work facilitates comparison with Cherenkov detector measurements, including those located at the Booster Neutrino Beam.

hep-ex↗

arXiv2026

Search for the production of Higgs-portal scalar bosons in the NuMI beam using the MicroBooNE detector

We present the strongest experimental limits to date on the mixing angle, $θ$, with which a new scalar particle, $S$, mixes with the Higgs field in the mass range $110\text{ MeV}<m_S<155\text{ MeV}$. This result uses the MicroBooNE liquid argon time projection chamber to search for decays of these Higgs-portal scalar particles through the $S\rightarrow e^+e^-$ channel with the decays of kaons in the NuMI neutrino beam acting as the source of the scalar particles. The analysis uses an exposure of $2.01\times 10^{21}$ protons on target of NuMI beam data including periods when the beam focusing system was configured to focus positively charged hadrons and separate periods when negatively charged hadrons were focused. The analysis searches for scalar particles produced from kaons decaying in flight in the beam's decay volume and at rest in the target and absorber. At $m_S=125\text{ MeV}$ ($m_S=150\text{ MeV})$ we set a limit of $θ<3.19\times 10^{-4}$ ($θ<2.79\times 10^{-4}$) at the 95% confidence level.

hep-ex↗

arXiv2026

Scintillation light calibrations, systematic uncertainties, and triggering efficiency in the MicroBooNE detector

Scintillation light, produced alongside ionisation charge from particle interactions, plays a critical role in liquid argon time projection chamber (LArTPC) detectors. A detailed understanding of its production and detection mechanisms is essential for robust calibration, systematic uncertainty evaluation, and physics analysis. This article describes the MicroBooNE light simulation, light-based triggering schemes, photomultiplier tube gain calibration, light response stability, and light-based systematic uncertainties over the course of five years of data collection. In addition, we present a measurement of scintillation light triggering efficiency, focusing on the lowest-light regime relevant to rare-event searches and low-energy neutrino interactions. Finally, we discuss two notable observations in MicroBooNE's data, both reported here for the first time: an approximately 50% decline in MicroBooNE's light yield over time, concentrated in the first two years of running; and a higher than expected O(200 kHz) rate of single photoelectron noise. The results presented provide an important benchmark of long-term light detection performance in LArTPC neutrino detectors.

physics.ins-det↗

arXiv2026

Measurements of differential charged-current cross sections on argon for electron neutrinos with final-state protons in MicroBooNE

This work presents single-differential electron-neutrino charged-current cross sections on argon measured using the MicroBooNE detector at the Fermi National Accelerator Laboratory. The analysis uses data recorded when the Neutrinos at the Main Injector beam was operating in both neutrino and antineutrino modes, with exposures of $2 \times 10^{20}$ and $5 \times 10^{20}$ protons on target, respectively. A selection algorithm targeting electron-neutrino charged-current interactions with at least one proton, one electron, and no pions in the final topology is used to measure differential cross sections as a function of outgoing electron energy, total visible energy, and opening angle between the electron and the most energetic proton. The interaction rate as a function of proton multiplicity is also reported. The total cross section is measured as [4.1 $\pm$ 0.3 (stat.) $\pm$ 1.1 (syst.)]$ $$\times 10^{-39} \mathrm{cm}^{2}/ \mathrm{nucleon}$. The unfolded cross-section measurements are compared to predictions from neutrino event generators commonly employed in the field. Good agreement is seen across all variables within uncertainties.

hep-ex↗

arXiv2026

Measurement of single charged pion production in charged-current $ν_μ$-Ar interactions with the MicroBooNE detector

We present flux-averaged charged-current $ν_μ$ cross-section measurements on argon for final states containing exactly one $π^\pm$ and no other hadrons except nucleons. The analysis uses data from the MicroBooNE experiment in the Booster Neutrino Beam, corresponding to $1.11 \times 10^{21}$ protons on target. Total and single-differential cross-section measurements are provided within a phase space restricted to muon momenta above 150 MeV, pion momenta above 100 MeV, and muon-pion opening angles smaller than 2.65 rad. Differential cross sections are reported with respect to the scattering angles of the muon and pion relative to the beam direction, their momenta, and their combined opening angle. The differential cross section with respect to muon momentum is based on a subset of selected events with the muon track fully contained in the detector, whereas the cross section with respect to pion momentum is based on a subset of selected events rich in pions that have not hadronically scattered on the argon before coming to rest. The latter has not been measured on argon before. The total cross section is measured as $(3.75~\pm~0.07~\textrm{(stat.)}~\pm~0.80~\textrm{(syst.)}) \times 10^{-38} \, \text{cm}^2/\text{Ar}$ at a mean energy of approximately 0.8 GeV. Comparisons of the measured cross sections with predictions from multiple neutrino-nucleus interaction generators show good overall agreement, except at very forward muon angles.

hep-ex↗

arXiv2026

Charge Transport and Multiplication in Lateral Amorphous Selenium Devices Under Cryogenic Conditions

Cryogenic photon sensing for high-energy physics motivates photosensor technologies that combine large-area scalability with internal gain and stable operation at low temperature. Amorphous selenium is a promising photoconductor, yet its field- and temperature-dependent transport and avalanche response in lateral geometries have not been systematically established. This work reports field-resolved photocurrent measurements of lateral a-Se devices from 93 K to 297 K under 401 nm excitation at fields up to 120 V/um. Below avalanche onset, the external quantum efficiency was described by the Onsager model, yielding effective post-thermalization separations that decrease with decreasing temperature. The field-assisted detrapping region was evaluated using several transport models, with the data favoring field-assisted hopping and thermally-assisted tunneling as the mechanisms that best capture the temperature evolution of the photocurrent. The boundaries between field-assisted detrapping, transport-limited conduction, and avalanche shift with temperature; at 93 K the response transitions directly from detrapping into avalanche. Avalanche multiplication was analyzed using the Lucky-drift model. These results provide the first systematic characterization of cryogenic avalanche behavior in lateral a-Se detectors and establish quantitative trends relevant to low-temperature, high-gain photodetector design.

cond-mat.mtrl-sci↗

arXiv2026

Reconstruction of atmospheric neutrinos in DUNE's horizontal-drift far-detector module

This paper reports on the capabilities in reconstructing and identifying atmospheric neutrino interactions in one of the Deep Underground Neutrino Experiment's (DUNE) far detector modules, a liquid argon time projection chamber (LArTPC) with horizontal drift (FD-HD) of ionization electrons. The reconstruction is based upon the workflow developed for DUNE's long-baseline oscillation analysis, with some necessary machine-learning models' retraining and the addition of features relevant only to atmospheric neutrinos such as the neutrino direction reconstruction. Where relevant, the impact of the detection of the charged particles of the hadronic system is emphasized, and comparisons are carried out between the case when lepton-only information is considered in the reconstruction (as is the case for many neutrino oscillation experiments), versus when all particles identified in the LArTPC were included. Three neutrino direction reconstruction methods have been developed and studied for the atmospheric analyses: using lepton-only information, using all reconstructed particles, and using only correlations from reconstructed hits. The results indicate that incorporating more than just lepton information significantly improves the resolution of both neutrino direction and energy reconstruction. The angle reconstruction algorithms developed in this work result in no strong dependence on particle direction for reconstruction efficiencies or neutrino flavor identification. This comprehensive review of the reconstruction of atmospheric neutrinos in DUNE's FD-HD LArTPC is the first step towards developing a first neutrino oscillation sensitivity analysis, which will ready DUNE for its first measurements.

hep-ex↗

arXiv2025

Supernova Pointing Capabilities of DUNE

The determination of the direction of a stellar core collapse via its neutrino emission is crucial for the identification of the progenitor for a multimessenger follow-up. A highly effective method of reconstructing supernova directions within the Deep Underground Neutrino Experiment (DUNE) is introduced. The supernova neutrino pointing resolution is studied by simulating and reconstructing electron-neutrino charged-current absorption on 40Ar and elastic scattering of neutrinos on electrons. Procedures to reconstruct individual interactions, including a newly developed technique called ``brems flipping'', as well as the burst direction from an ensemble of interactions are described. Performance of the burst direction reconstruction is evaluated for supernovae happening at a distance of 10 kpc for a specific supernova burst flux model. The pointing resolution is found to be 3.4 degrees at 68% coverage for a perfect interaction-channel classification and a fiducial mass of 40 kton, and 6.6 degrees for a 10 kton fiducial mass respectively. Assuming a 4% rate of charged-current interactions being misidentified as elastic scattering, DUNE's burst pointing resolution is found to be 4.3 degrees (8.7 degrees) at 68% coverage.

hep-ex↗

arXiv2025

Gamma-Ray and AntiMatter Survey(GRAMS) experiment

The Gamma-Ray and AntiMatter Survey (GRAMS) is a next-generation experiment using a Liquid Argon Time Projection Chamber (LArTPC) detector to measure MeV gamma rays and antiparticles. MeV gamma-ray observations are important for understanding multi-messenger and time-domain astronomy, enabling exploration of the universe's most potent events, such as supernovae and neutron star mergers. Despite the significance of MeV gamma-rays, GRAMS could also explore the so-called 'MeV gap' region to improve MeV gamma-ray measurement sensitivity that was restricted by the challenge of accurately reconstructing Compton events. Aside from gamma-ray detection, the GRAMS proposed method also serves as an antiparticle spectrometer, targeting the low-energy range of cosmic antinuclei measurements. This work will provide updates on the current status and progress towards the prototype balloon flight with a small-scale LArTPC (pGRAMS) scheduled for early 2026, as well as the recent progress on antihelium-3 sensitivity calculation.

hep-ex↗

arXiv2025

Search for Light Sterile Neutrinos With Two Neutrino Beams at MicroBooNE

The existence of three distinct neutrino flavours, $ν_{e}$, $ν_μ$, and $ν_τ$, is a central tenet of the Standard Model of particle physics. Quantum-mechanical interference can allow a neutrino of one initial flavour to be detected some time later as a different flavour, a process called neutrino oscillation. Several anomalous observations inconsistent with this three-flavour picture have motivated the hypothesis that an additional neutrino state exists which does not interact directly with matter, termed a "sterile" neutrino, $ν_s$. This includes anomalous observations from the LSND and MiniBooNE experiments, consistent with $ν_μ\rightarrowν_{e}$ transitions at a distance inconsistent with the three-neutrino picture. Here, we use data obtained from the MicroBooNE liquid-argon time projection chamber in two accelerator neutrino beams to exclude the single light sterile neutrino interpretation of the LSND and MiniBooNE anomalies at the 95\% confidence level (CL). Additionally, we rule out a significant portion of the parameter space that could explain the gallium anomaly. This is the first measurement to use two accelerator neutrino beams to break a degeneracy between $ν_{e}$ appearance and disappearance that would otherwise weaken the sensitivity to the sterile neutrino hypothesis. We find no evidence for either $ν_μ\rightarrowν_{e}$ flavour transitions or $ν_{e}$ disappearance that would indicate non-standard flavour oscillations. Our results show that previous anomalous observations consistent with $ν_μ\rightarrowν_{e}$ transitions cannot be explained by introducing a single sterile neutrino state.

hep-ex↗

arXiv2025

Measurement of three-dimensional inclusive muon-neutrino charged-current cross sections on argon with the MicroBooNE detector

We report the measurement of the differential cross section $d^{2}σ(E_ν)/ d\cos(θ_μ) dP_μ$ for inclusive muon-neutrino charged-current scattering on argon. This measurement utilizes data from 6.4$\times10^{20}$ protons on target of exposure collected using the MicroBooNE liquid argon time projection chamber located along the Fermilab Booster Neutrino Beam with a mean neutrino energy of approximately 0.8~GeV. The mapping from reconstructed kinematics to truth quantities, particularly from reconstructed to true neutrino energy, is validated within uncertainties by comparing the distribution of reconstructed hadronic energy in data to that of the model prediction in different muon scattering angle bins after applying a conditional constraint from the muon momentum distribution in data. The success of this validation gives confidence that the missing energy in the MicroBooNE detector is well-modeled within uncertainties in simulation, enabling the unfolding to a three-dimensional measurement over muon momentum, muon scattering angle, and neutrino energy. The unfolded measurement covers an extensive phase space, providing a wealth of information useful for future liquid argon time projection chamber experiments measuring neutrino oscillations. Comparisons against a number of commonly used model predictions are included and their performance in different parts of the available phase-space is discussed.

hep-ex↗

arXiv2025

Measurement of Exclusive $π^+$--argon Interactions Using ProtoDUNE-SP

We present the measurement of $π^{+}$--argon inelastic cross sections using the ProtoDUNE Single-Phase liquid argon time projection chamber in the incident $π^+$ kinetic energy range of 500 -- 800 MeV in multiple exclusive channels (absorption, charge exchange, and the remaining inelastic interactions). The results of this analysis are important inputs to simulations of liquid argon neutrino experiments such as the Deep Underground Neutrino Experiment and the Short Baseline Neutrino program at Fermi National Accelerator Laboratory. They will be employed to improve the modeling of final state interactions within neutrino event generators used by these experiments, as well as the modeling of $π^{+}$--argon secondary interactions within the liquid argon. This is the first measurement of $π^+$--argon absorption at this kinetic energy range as well as the first ever measurement of $π^{+}$--argon charge exchange.

hep-ex↗

arXiv2025

Enhanced search for neutral current $Δ$ radiative single-photon production in MicroBooNE

We report results from an updated search for neutral current (NC) resonant $Δ$(1232) baryon production and subsequent $Δ$ radiative decay (NC $Δ\rightarrow N γ$). We consider events with and without final state protons; events with a proton can be compared with the kinematics of a $Δ(1232)$ baryon decay, while events without a visible proton represent a more generic phase space. In order to maximize sensitivity to each topology, we simultaneously make use of two different reconstruction paradigms, Pandora and Wire-Cell, which have complementary strengths, and select mostly orthogonal sets of events. Considering an overall scaling of the NC $Δ\rightarrow N γ$ rate as an explanation of the MiniBooNE anomaly, our data exclude this hypothesis at 94.4% CL. When we decouple the expected correlations between NC $Δ\rightarrow N γ$ events with and without final state protons, and allow independent scaling of both types of events, our data exclude explanations in which excess events have associated protons, and do not exclude explanations in which excess events have no associated protons.

hep-ex↗

arXiv2025

First Measurement of Charged Current Muon Neutrino-Induced $K^+$ Production on Argon using the MicroBooNE Detector

The MicroBooNE experiment is an 85 tonne active mass liquid argon time projection chamber neutrino detector exposed to the on-axis Booster Neutrino Beam (BNB) at Fermilab. One of MicroBooNE's physics goals is the precise measurement of neutrino interactions on argon in the 1 GeV energy regime. Building on the capabilities of the MicroBooNE detector, this analysis identifies $K^{+}$ mesons, a key signature for the study of strange particle production in neutrino interactions. This measurement is furthermore valuable for background estimation for future nucleon decay searches and for improved reconstruction and particle identification capabilities in experiments such as the Deep Underground Neutrino Experiment (DUNE). In this letter, we present the first-ever measurement of a flux-integrated cross section for charged-current muon neutrino induced $K^{+}$ production on argon nuclei, determined to be 7.93 $\pm$ 3.22 (stat.) $\pm$ 2.83 (syst.) $\times~10^{-42}\;$ cm$^2$/nucleon based on an analysis of 6.88$\times10^{20}$ protons on target. This result was found to be consistent with model predictions from different neutrino event generators within the reported uncertainties.

hep-ex↗

arXiv2025

Cryogenic UV detection using stress-engineered zero-bias ZnO-thin film based Piezo-Photonic detector

We demonstrate a zero-bias ultraviolet (UV) detector using zinc oxide (ZnO) thin films as the active semiconductor layer, specifically for application in cryogenic conditions. The zero-bias device utilizes the piezoelectric potential developed through interfacial stress in the active semiconductor layer for charge transport. We explored two vertically stacked metal-semiconductor-metal (MSM) configurations: Sample I, a device comprised of chromium (Cr)/ZnO/Cr layers, and Sample II, a ZnO-silicon nitride (Si3N4) device comprised of Cr/Si3N4/ZnO/Cr layers. The Si3N4 layer in Sample II was introduced in the form of pillars, with the aim of increasing the residual stress in the active region. These fabricated devices were tested at both room and cryogenic temperatures to characterize their UV-detection performance in a custom test stand using a 365 nm UV LED source. We observe a higher UV-induced voltage signal for Sample II in comparison to Sample I at both temperature regimes. Grazing-incidence X-ray diffraction (GIXRD) measurements showed approximately 40% higher residual stress in Sample II than in Sample I. A higher residual stress suggests a higher induced piezopotential in Sample II, explaining the enhancement in the UV-induced signal. Our results demonstrate that through appropriate in-device stress engineering, UV photoinduced signals can be enhanced, increasing detector sensitivity. A zero-bias photodetector with in-device stress engineering, as demonstrated here, can have applications in extreme environments, like cryogenic liquid noble elements or high radiation space environments, where low or zero-power detection may be required.

cond-mat.mtrl-sci↗

arXiv2025

Characterization of Lateral Amorphous Selenium Photodetectors for Low-Photon and VUV Detection at Cryogenic Temperatures

The performance of amorphous selenium (a-Se) as a cryogenic photodetector material is evaluated through a series of experiments using laterally structured devices operated in a custom optical test stand. These studies investigate the response of a-Se detectors to low-photon fluxes at high electric fields near avalanche conditions, the linearity of the photoconductive response over a wide dynamic range and the direct detection of narrowband 130 nm vacuum ultraviolet (VUV) illumination. At 87 K, matched-filter analysis shows reliable single-shot detection with efficiencies greater than or equal to 80 percent and area under the curve (AUC) greater than or equal to 0.85 using as few as approximately 6800 incident 401 nm photons, corresponding to approximately 3400 photons within field-active regions after accounting for geometric constraints. Measurements are performed at cryogenic temperatures using calibrated photon fluxes derived from a silicon photomultiplier reference and a characterized optical filter stack. Additional experiments using a tellurium-doped a-Se (a-SeTe) device explore the material's behavior under identical test conditions and demonstrate that avalanche is achievable in a-SeTe at cryogenic temperatures. The results demonstrate reproducible low-noise operation, VUV sensitivity and field-dependent gain behavior in a lateral a-Se architecture, representing the first reported observation of avalanche multiplication in laterally structured a-Se and a-SeTe devices at cryogenic temperatures. These findings support the potential integration of laterally structured a-Se devices into next-generation pixelated liquid-argon time projection chambers (TPCs) requiring scalable, high-field-compatible photon detection systems.

physics.ins-det↗

arXiv2025

Identification of low-energy kaons in the ProtoDUNE-SP detector

The Deep Underground Neutrino Experiment (DUNE) is a next-generation neutrino experiment with a rich physics program that includes searches for the hypothetical phenomenon of proton decay. Utilizing liquid-argon time-projection chamber technology, DUNE is expected to achieve world-leading sensitivity in the proton decay channels that involve charged kaons in their final states. The first DUNE demonstrator, ProtoDUNE Single-Phase, was a 0.77 kt detector that operated from 2018 to 2020 at the CERN Neutrino Platform, exposed to a mixed hadron and electron test-beam with momenta ranging from 0.3 to 7 GeV/c. We present a selection of low-energy kaons among the secondary particles produced in hadronic reactions, using data from the 6 and 7 GeV/c beam runs. The selection efficiency is 1\% and the sample purity 92\%. The initial energies of the selected kaon candidates encompass the expected energy range of kaons originating from proton decay events in DUNE (below $\sim$200 MeV). In addition, we demonstrate the capability of this detector technology to discriminate between kaons and other particles such as protons and muons, and provide a comprehensive description of their energy loss in liquid argon, which shows good agreement with the simulation. These results pave the way for future proton decay searches at DUNE.

hep-ex↗

arXiv2025

Towards mono-energetic virtual $ν$ beam cross-section measurements: A feasibility study of $ν$-Ar interaction analysis with DUNE-PRISM

Neutrino-nucleus cross-section measurements are critical for future neutrino oscillation analyses. However, our models to describe them require further refinement, and a deeper understanding of the underlying physics is essential for future neutrino oscillation experiments to realize their ambitious physics goals. Current neutrino cross-section measurements provide clear deficiencies in neutrino interaction modeling, but almost all are reported averaged over broad neutrino fluxes, rendering their interpretation challenging. Using the DUNE-PRISM concept (Deep Underground Neutrino Experiment Precision Reaction Independent Spectrum Measurement) -- a movable near detector that samples multiple off-axis positions -- neutrino interaction measurements can be used to construct narrow virtual fluxes (less than 100 MeV wide). These fluxes can be used to extract charged-current neutrino-nucleus cross sections as functions of outgoing lepton kinematics within specific neutrino energy ranges. Based on a dedicated simulation with realistic event statistics and flux-related systematic uncertainties, but assuming an almost-perfect detector, we run a feasibility study demonstrating how DUNE-PRISM data can be used to measure muon neutrino charged-current integrated and differential cross sections over narrow fluxes. We find that this approach enables a model independent reconstruction of powerful observables, including energy transfer, typically accessible only in electron scattering measurements, but that large exposures may be required for differential cross-section measurements with few-\% statistical uncertainties.

hep-ex↗