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DOE OSTI2021

Double-differential Measurements of Mesonless Charged-current Muon Neutrino Interactions on Argon with Final-State Protons using the MicroBooNE Detector

This note reports the first double-differential measurements of charged-current $ν_µ$ scattering on argon leading to final states containing zero mesons and one or more protons. This event topology (hereafter abbreviated as CC0$πNp$) is the most common at the neutrino energies typically produced by the Fermilab Booster Neutrino Beam. A detailed understanding of neutrino-argon scattering in the CC0$πNp$ channel is therefore crucial for the success of the precision neutrino oscillation analyses planned for the Short-Baseline Neutrino (SBN) program. This remains true for the upcoming Deep Underground Neutrino Experiment (DUNE), but the higher mean neutrino energy used there will ensure that more inelastic reaction modes, such as single pion production, will also play a major role. The analysis described in this note builds on a previous MicroBooNE study of the CC0$πNp$ channel which obtained the first single-differential cross-section measurements on an argon target. Since that foundational work, significant improvements have been made to MicroBooNE’s simulation software, event reconstruction algorithms, and procedure for calculating systematic uncertainties. When combined with a larger dataset (corresponding to a beam exposure of 6.79 × 10 20 protons-on-target versus 1.60 × 10 20 in Ref. [3]), these enhancements allow the important CC0$πNp$ channel to be studied in more detail. This note begins with a description of the data and simulation samples used as input to the analysis. Section 3 then defines the CC0$πNp$ signal event topology, and Section 4 describes a set of selection criteria designed to identify these events in MicroBooNE data. Binning schemes are then defined in Section 5 for two double-differential measurements of event rates. The first of these considers the momentum and scattering cosine of the outgoing muon, while the second reports the same observables for the leading proton, i.e., the final-state proton with the largest momentum. After a discussion of systematic uncertainties in Section 6, the note concludes by comparing the predictions of MicroBooNE Monte Carlo (MC) simulations to the measured double-differential distributions. These results will form the basis for a future extraction of flux-averaged double-differential CC0$πNp$ cross sections that will be immediately comparable to the theoretical predictions of multiple neutrino event generators. The selection described herein may also be used to study various other observables in CC0$πNp$ events, including those which are sensitive to correlations between leptonic and hadronic kinematics in the final state.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2024

ADRIANO2 Calorimeter Performance from 2022 Test Beams

A novel high-granularity dual-readout calorimetric technique was developed as part of the T1604 collaboration. The ADRIANO2 Calorimeter Prototype consists of a pair of optically isolated, small sized tiles made of scintillating plastic and lead glass. Čerenkov light from the lead glass are exploited to for high resolution timing measurements, while high granularity from scintillating plastic can be used to probe the spatial component of the particle shower. This setup works for excellent energy resolution and particle detection for REDTOP as it is crucial for a calorimeter to detect the decay products of eta/eta-prime mesons. Measurements were collected on ADRIANO2 between February to December 2022 to evaluate the detector performance at Fermilab’s Test Beam Facility. The key metrics extracted from my analysis are the detector’s efficiency for various tile configuration and light-yield which will then be used as parameters for an upgraded REDTOP monte-carlo simulation campaign. An in-depth analysis of ADRIANO2 performance are detailed in this presentation.

43 PARTICLE ACCELERATORS↗

DOE OSTI2024

N* Physics with CLAS12 at Jefferson Lab

Nucleons are the most fundamental bound three-body systems in Nature. With the CLAS12 spectrometer at Jefferson Lab, the spectrum and the structure of nucleon resonances is explored. This includes studies of exclusive piN, pi+pi-p, KLambda, and KSigma electroproduction reactions and the evolution of the electrocouplings of resonances with photon virtuality Q^2. Such type of studies with CLAS have revealed a complex interplay between a core of dressed quarks and an external meson-baryon cloud inside of the excited nucleon states. With CLAS12, also measurements of N -> N* transitions in the DIS region have been performed, addressing the three-dimensional structure of nucleon resonances through their transition GPDs (generalized parton distributions). In the future, the increase of the CEBAF energy and the upgrade of the CLAS12 spectrometer to study exclusive electroproduction channels at higher luminosities and photon virtualities will offer a unique opportunity to study the nucleon excitation mechanisms.

Achenbach, Patrick↗

DOE OSTI2024

Near-threshold photoproduction of J/ of a proton with the CLAS12 experiment

The photo-production of vector mesons off the proton has long been established as an important tool to access the gluon content of the nucleon. In particular, the photo-production of J/Psi near the threshold energy has been related to the Gravitational Form Factors of the gluons which provide information about the mass and the force distributions in the nucleon. In this talk, I will present results on the near-threshold photoproduction of J/Psi using data taken in 2018 and 2019 by the CLAS12 detector at Jefferson Lab, with an electron beam impinging on a liquid-hydrogen target. This measurement is expected to provide direct insight on the gluons distribution inside the proton.

Chatagnon, Pierre↗

DOE OSTI2024

An Updated Simulation of the Booster Neutrino Beam

For accelerator neutrino experiments, an accurate prediction of the incoming neutrino flux is crucial for reducing uncertainties for all physics measurements. In this exciting period for the Short-Baseline Neutrino program at Fermilab, with far detector (ICARUS) already operating and the near detector (SBND) nearing operation, an updated flux model for the Booster Neutrino Beam (BNB) is presented. The BNB delivers 8 GeV protons to a beryllium target, subsequently producing neutrinos from the decay of the secondary beam of hadrons. A updated Monte-Carlo simulation of beam production in GEANT4 has been created, allowing predictions to be made for detectors with different baselines, offsets and sizes. This new simulation contains new features, such as a full neutrino ancestry to handle hadron production systematics with more precision, with a view to storing all resulting particles - including neutral mesons - from the proton-Beryllium scatter to allow the study of exotic BSM scenarios. Results are presented, with comparisons to the original flux simulated for the MiniBooNE experiment.

Paton, Josephine↗

DOE OSTI2025

Light Dark Matter Searches at Fermilab

Accelerator-based dark sector searches present an excellent opportunity to discover the particles that constitute cosmological dark matter in a laboratory setting. At Fermilab, an exciting program of dark sector searches is now underway across a suite of experiments using high intensity, low- and high-energy proton beamlines. Some of these searches are being carried out at neutrino experiments, which bring high luminosity sources of meson decays near large, sensitive detectors and can therefore probe a variety of dark sector models. Additionally, there have been recent studies highlighting the sensitivity of future and proposed experiments to light dark matter and other dark sector models using protons from Fermilab s new PIP-II linac, currently under construction. In this talk, I will give an overview of Fermilab s accelerator-based dark sector search program, highlight recent results, and discuss future prospects.

43 PARTICLE ACCELERATORS↗

DOE OSTI2025

Status of the Jefferson Lab Eta Factory (JEF) experiment

The Jefferson Lab Eta Factory (JEF) experiment is an experiment running in Hall D at Jefferson Lab that focuses on studying the decays of the ¿ meson. These decays provide a rich laboratory for searching for new charge conjugation violating / parity conserving (CVPC) processes, looking for hints of Beyond Standard Model physics, and probing higher order terms in Chiral Perturbation Theory. The flagship channel is the rare decay ¿ ¿ p0¿¿, the measurement of which required an upgrade to the existing equipment in Hall D. The experiment uses the GlueX detector, a fixed-target large acceptance spectrometer based on a solenoid magnet containing drift chambers for tracking charged particles and a lead-scintillator barrel calorimeter in the central region and an array of 4 × 4 × 45 cm3 lead glass blocks in the forward region for detecting neutral particles. During the last two years the inner 80×80 cm2 region of the forward calorimeter has been replaced by an array of 2 × 2 × 20 cm3 lead tungstate crystals, which provide factors of two improvement in energy and position resolution. The first round of data taking with this configuration took place this year. A first look at the data will be presented.

Taylor, Simon [Thomas Jefferson National Accelerat↗

DOE OSTI2025

Implementation of INCL Nuclear Model in GENIE Generator

The Li ge Intranuclear Cascade (INCL) model is a nuclear-physics model that simulates hadron (baryon, anti-baryon and meson) reactions on nuclei, for incident energies ranging from a few tens of MeV to 10-20 GeV. The INCL model has been well validated by hadron scattering data. In my work, I implement an interface in GENIE to use the INCL nuclear model in the simulations of both the initial state of the target nucleus and the Final State Interaction in neutrino-nucleus interaction. It has a consistent treatment of nuclear models in both neutrino interaction and hadron rescattering. A full event record including neutrino vertex and each vertex of hadron rescattering has been accomplished. Several processes, e.g. cluster production, Delta transportation and de-excitation will also be included as benefits of the implementation of the INCL model in GENIE. I will show some initial simulation results showcasing the new GENIE features and discuss plans for making them available for use in experimental analyses.

Liu, Liang [Fermilab]↗

DOE OSTI2025

LANSCE Accelerator Modernization Project Conceptual Design Report

The accelerator complex now known as the Los Alamos Neutron Science Center (LANSCE) began operation in 1972 as LAMPF, the Los Alamos Meson Production Facility. In the intervening 53 years, the complex has been expanded in capability several times, both in terms of its accelerator performance and the user facilities it supports.

43 PARTICLE ACCELERATORS↗

DOE OSTI2025

Implementation of INCL nuclear model in GENIE Generator

The Liège Intranuclear Cascade (INCL) model is a nuclear-physics model that simulates hadron (baryon, anti-baryon and meson) reactions on nuclei, for incident energies ranging from a few tens of MeV to 10-20 GeV. The INCL model has been well validated by hadron scattering data. In my work, I implement an interface in GENIE to use the INCL nuclear model in the simulations of both the initial state of the target nucleus and the Final State Interaction in neutrino-nucleus interaction. It has a consistent treatment of nuclear models in both neutrino interaction and hadron rescattering. A full event record including neutrino vertex and each vertex of hadron rescattering has been accomplished. Several processes, e.g. cluster production, Delta transportation and de-excitation will also be included as benefits of the implementation of the INCL model in GENIE. I will show some initial simulation results showcasing the new GENIE features and discuss plans for making them available for use in experimental analyses.

Liu, Liang [Fermilab] (ORCID:000000026753925X)↗

DOE OSTI2025

Phenomenological Chiral Perturbation Theory for Event Generators

Understanding neutrino induced single pion production off of nucleons is crucial for accelerator-based neutrino oscillation experiments. To this end, we use chiral perturbation theory to determine the forms of meson and baryon interactions and then modify the vertices using form factors. We implement this single pion production model in an event generator pipeline that will be available to the wider community.

Toman, Miša [UC, Irvine] (ORCID:0009000326471281)↗

DOE OSTI2025

Status and Performance of the GlueX DIRC

The GlueX experiment is located in experimental Hall D at Jefferson Lab (JLab) and provides a unique capability to search for hybrid mesons in high-energy photoproduction, utilizing a $\sim$9 GeV linearly polarized photon beam. Since 2020 a Detector of Internally Reflected Cherenkov light (DIRC) has been in use at GlueX, utilizing components from the decommissioned BaBar DIRC. In this contribution we will discuss the status and performance of the GlueX DIRC with the data collected to date, including recent developments in the use of machine learning for particle identification.

Stevens, Justin [College of William and Mary, Will↗

DOE OSTI2025

Spin-Density Matrix Elements in K∗(892) Photoproduction with Recoiling Λ at GlueX

We report on the measurement of spin-density matrix elements for the K∗(892) → K+π0 photoproduction process with a recoiling Λ hyperon. The measurement used high-statistics GlueX data from photoproduction off a proton target at photon energies between 8.2 and 8.8 GeV, in a kinematic regime dominated by t-channel exchange processes. GlueX is a fixed-target experiment with a linearly polarized photon beam and a nearly 4π hermetic detector, allowing extraction of the full spin observ- ables from both the K+π0 and Λ → π−p systems. The GlueX data show clear evidence of the K∗(892) resonance in the K+π0 mass spectrum, along with additional structures at higher masses that may correspond to K∗0 or K∗2 resonances. The precise measurement of the spin-density matrix elements of the K∗(892) could serve as a standard candle for con- tinuing studies of higher-mass excited K∗ states. In addition, t-channel K∗ photoproduction differs from previous measurements of non-strange vector meson photoproduction, as it is free from Pomeron exchange and is virtually unexplored in this energy regime. Furthermore, the unprece- dented data collected by GlueX allow for investigations of correlations between the Λ polarization and the spin-density matrix elements of K∗ production, paving the way for future partial-wave analyses with full spin information involving the recoil hyperon.

Li, Hao [College of William and Mary, Williamsburg↗

DOE OSTI2026

Updating the BNB Flux Prediction at SBND

Precise, accurate neutrino flux predictions for neutrino beam experiments are crucial for physics results. Flux uncertainties contribute significantly to the total systematic uncertainties seen in modern accelerator neutrino measurements such as cross sections, oscillations, and BSM studies.. For over a decade, experiments utilizing Fermilab’s Booster Neutrino Beam (BNB) have relied on the 2009 MiniBooNE flux prediction. However, the high-statistics era of the Short-Baseline Neutrino (SBN) program, with both SBND and ICARUS now operating, demands a modernized flux model and framework. While SBND is using the MiniBooNE flux model for its Generation 1 analyses, including many upcoming cross section measurements, future work will be based on a new flux model. In this talk, the ongoing work towards this new model will be outlined, including a new simulation framework (G4BNB), a new evaluation of model parameters from hadron scattering data, and a new framework for evaluating systematic uncertainties (BNBFP). Additionally, expansions to the flux model to include BSM contributions from neutral mesons will be discussed, as well as the PRISM capabilities of SBND to observe a wide range of off axis angles of the neutrino beam.

Paton, Josephine [Fermilab]↗

DOE OSTI2026

Updating the BNB Flux Prediction at SBND

Paton, Josephine [Fermilab]↗

DOE OSTI2026

Final Technical Report for U.S.-Japan Hadronic Physics Exchange Program for Studies of Hadron Structure and QCD

Nuclear physics explores the fundamental properties of matter -- how protons and neutrons emerge as quantum systems of elementary particles, how they form the atomic nuclei, and how they give rise to the wide variety of phenomena and applications at biological, technical, and astronomical scales. It is a global scientific effort centered around large-scale experimental user facilities (particle accelerators and detectors), advanced theoretical methods and concepts, and computational techniques and resources. Exchange of knowledge and ideas, scientific collaboration, and workforce development on a global scale are essential for the future of the field. The nuclear physics program envisaged in the 2023 DOE/NSF NSAC Long-Range Plan and pursued at the U.S. National Labs has strong synergies with programs at other facilities worldwide and will realize significant benefits from international collaboration. Nuclear physics is also recognized for promoting international cooperation in the broadest sense through joint construction and operation of experimental equipment, personal contacts between scientists, and education and training. The U.S.-Japan Hadronic Physics Exchange Program (USJPHE) supported collaborative scientific research in hadronic physics and quantum chromodynamics. USJHPE focused on subject areas related to the programs at current and future experimental facilities in the U.S.\ and Japan and supported both experimental and theoretical studies. USJHPE particularly aimed to realize synergies between the hadronic physics programs at Jefferson Lab 12 GeV and J-PARC resulting from the complementarity of electromagnetic and hadronic probes in the multi-GeV energy range. Subject areas of common interest included the quark-gluon structure of hadrons and nuclei, meson and baryon spectroscopy, strangeness and hypernuclear physics, and other related topics. USJHPE also supported research in hadronic physics and nuclear-physics-enabled tests of fundamental symmetries related to the programs at Brookhaven National Lab, Fermilab, KEK, Spring-8, and university-based facilities in the U.S. and Japan. USJHPE especially promoted collaboration between the U.S. and Japanese nuclear physics communities in developing the physics program and instrumentation for the future Electron-Ion Collider. USJHPE was intended to provide travel grants to U.S.-based scientists (primary institutional affiliation with a U.S.\ university, national laboratory, or other research center) to visit Japanese institutions and conduct collaborative research there. The program supported senior researchers, postdoctoral fellows, and students. Continuing the setup of the preceding grant period, J-PARC served as the Japanese “hub” for U.S. physicists for short- and long-term visits, and JLab served as the corresponding U.S. “hub”. The program was officially managed through the U. of Connecticut in Storrs, CT. Support for Japanese physicists visiting the U.S. was provided through funds from Japanese funding agencies. The USJHPE program promoted the scientific exchange and the collaborative spirit in hadronic physics between the two countries.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2026

Towards searches for heavy neutral leptons with the Short-Baseline Near Detector experiment

Heavy Neutral Leptons (HNLs) are hypothetical long-lived particles that extend the Standard Model and provide a natural explanation for the origin of neutrino masses, the generation of the baryon asymmetry through leptogenesis, and the nature of dark matter. The Short-Baseline Near Detector (SBND) is a 112-ton liquid argon time projection chamber located 110 m away from the Booster Neutrino Beam (BNB) target at Fermilab (Illinois, USA). The close location to the BNB origin makes the experiment sensitive to HNLs produced from meson decays in the beam. These heavy particles arrive at the detector later than neutrinos and decay into observable final states such as 𝜈e+e- or 𝜈π0, generating isolated electromagnetic showers. Thanks to SBND’s advanced scintillation light detection system, a timing resolution at the nanosecond level further boosts the experiment capabilities. In this poster, we present ongoing reconstruction efforts towards HNLs as well as expected sensitivities factoring in the reconstruction improvements.

Romeo Araujo, Jorge [Madrid, CIEMAT]↗

DOE OSTI2026

First Measurement of Charged Current Muon Neutrino-Induced Kaon Production on Argon using the MicroBooNE Detector

MicroBooNE is an 85-tonne active mass liquid argon time projection chamber (LArTPC) neutrino detector exposed to the Booster Neutrino Beamline (BNB) at Fermilab. One of the key physics goals is the precise measurement of neutrino interactions on argon in the 1 GeV energy regime. The study of strange and heavier meson production in neutrino interactions, in particular final states containing $K^{+}$, will help to improve the background estimates for future nucleon decay searches in experiments such as DUNE, provide valuable input for improving neutrino generator models, and will allow the development of techniques to enhance the particle identification capabilities of LArTPCs. In this work, we present the first-ever cross-section measurements of charged current muon neutrino-induced kaon production on argon at MicroBooNE.

Rodriguez Rondon, Jairo H. [South Dakota Sch. Mine↗