arXiv subjects

J. Hylen

Publications and source records attributed to J. Hylen.

At least 19 recordsLinked to original sources

arXiv2024

Pressure Spike in The LBNF Absorber Core s Gun Drilled Cooling Channel from an Accident Beam Pulse

The LBNF Absorber consists of thirteen 6061-T6 aluminum core blocks. The core blocks are water cooled with de-ionized (DI) water which becomes radioactive during beam operations. The cooling water flows through gun-drilled channels in the core blocks. The cooling water is supplied by the LBNF Absorber Radioactive Water (RAW) cooling system which is designed as per ASME B31.3 Normal Fluid Service [1]. An uninhibited beam accident pulse striking the water channels was identified as a credible accident scenario. In this study, it is assumed that the beam pulse hits the Absorber directly without interacting with any of the other upstream beamline components. The beam parameters used for the LBNF beam are 120 GeV, 2.4 MW with a 1.2 s cycle time. The accident pulse lasts for 10 μs. The maximum energy is deposited in the 3rd aluminum core block. For the sake of simplicity, it is assumed that the accident pulse strikes the 1 in. ID water channel directly. The analysis here simulates the pressure rise in the water during and after the beam pulse and its effects on the aluminum piping components that deliver water to the core blocks. The weld strengths as determined by the Load and Resistance Factor Design (LRDF) and the Allowable Strength Design (ASD) are compared to the forces generated in the weld owing to the pressure spike. A transient structural analysis was used to determine the equivalent membrane, peak, and bending stresses and they were com-pared to allowable limits.

physics.acc-ph↗

arXiv2021

Search for multi-messenger signals in NOvA coincident with LIGO/Virgo detections

Using the NOvA neutrino detectors, a broad search has been performed for any signal coincident with 28 gravitational wave events detected by the LIGO/Virgo Collaboration between September 2015 and July 2019. For all of these events, NOvA is sensitive to possible arrival of neutrinos and cosmic rays of GeV and higher energies. For five (seven) events in the NOvA Far (Near) Detector, timely public alerts from the LIGO/Virgo Collaboration allowed recording of MeV-scale events. No signal candidates were found.

hep-ex↗

arXiv2021

Search for Slow Magnetic Monopoles with the NOvA Detector on the Surface

We report a search for a magnetic monopole component of the cosmic-ray flux in a 95-day exposure of the NOvA experiment's Far Detector, a 14 kt segmented liquid scintillator detector designed primarily to observe GeV-scale electron neutrinos. No events consistent with monopoles were observed, setting an upper limit on the flux of $2\times 10^{-14} \mathrm{cm^{-2}s^{-1}sr^{-1}}$ at 90% C.L. for monopole speed $6\times 10^{-4} < β< 5\times 10^{-3}$ and mass greater than $5\times 10^{8}$ GeV. Because of NOvA's small overburden of 3 meters-water equivalent, this constraint covers a previously unexplored low-mass region.

hep-ex↗

arXiv2020

Adjusting Neutrino Interaction Models and Evaluating Uncertainties using NOvA Near Detector Data

The two-detector design of the NOvA neutrino oscillation experiment, in which two functionally identical detectors are exposed to an intense neutrino beam, aids in canceling leading order effects of cross-section uncertainties. However, limited knowledge of neutrino interaction cross sections still gives rise to some of the largest systematic uncertainties in current oscillation measurements. We show contemporary models of neutrino interactions to be discrepant with data from NOvA, consistent with discrepancies seen in other experiments. Adjustments to neutrino interaction models in GENIE that improve agreement with our data are presented. We also describe systematic uncertainties on these models, including uncertainties on multi-nucleon interactions from a newly developed procedure using NOvA near detector data.

hep-ex↗

arXiv2020

High-statistics measurement of neutrino quasielastic-like scattering at =~6 GeV on a hydrocarbon target

We measure neutrino charged current quasielastic-like scattering on hydrocarbon at high statistics using the wide-band NuMI beam with neutrino energy peaked at 6 GeV. The double-differential cross section is reported in terms of muon longitudinal and transverse momentum. Cross-section contours versus lepton momentum components are approximately described by a conventional generator-based simulation, however discrepancies are observed for transverse momenta above 0.5 GeV/c for longitudinal momentum ranges 3 to 5 GeV/c and 9 to 20 GeV/c. The single differential cross section versus momentum transfer squared ($dσ/dQ_{QE}^2$) is measured over a four-decade range of $Q^2$ that extends to $10~GeV^2$. The cross section turn-over and fall-off in the $Q^2$ range 0.3 to $10~GeV^2$ is not fully reproduced by generator predictions that rely on dipole form factors. Our measurement probes the axial-vector content of the hadronic current and complements the electromagnetic form factor data obtained using electron-nucleon elastic scattering. These results help oscillation experiments because they probe the importance of various correlations and final-state interaction effects within the nucleus, which have different effects on the visible energy in detectors.

hep-ex↗

arXiv2020

Supernova neutrino detection in NOvA

The NOvA long-baseline neutrino experiment uses a pair of large, segmented, liquid-scintillator calorimeters to study neutrino oscillations, using GeV-scale neutrinos from the Fermilab NuMI beam. These detectors are also sensitive to the flux of neutrinos which are emitted during a core-collapse supernova through inverse beta decay interactions on carbon at energies of $\mathcal{O}(10~\text{MeV})$. This signature provides a means to study the dominant mode of energy release for a core-collapse supernova occurring in our galaxy. We describe the data-driven software trigger system developed and employed by the NOvA experiment to identify and record neutrino data from nearby galactic supernovae. This technique has been used by NOvA to self-trigger on potential core-collapse supernovae in our galaxy, with an estimated sensitivity reaching out to 10~kpc distance while achieving a detection efficiency of 23\% to 49\% for supernovae from progenitor stars with masses of 9.6M$_\odot$ to 27M$_\odot$, respectively.

physics.ins-det↗

arXiv2020

Measurement of Neutrino-Induced Neutral-Current Coherent $π^0$ Production in the NOvA Near Detector

The cross section of neutrino-induced neutral-current coherent $π^0$ production on a carbon-dominated target is measured in the NOvA near detector. This measurement uses a narrow-band neutrino beam with an average neutrino energy of 2.7\,GeV, which is of interest to ongoing and future long-baseline neutrino oscillation experiments. The measured, flux-averaged cross section is $σ= 13.8\pm0.9 (\text{stat})\pm2.3 (\text{syst}) \times 10^{-40}\,\text{cm}^2/\text{nucleus}$, consistent with model prediction. This result is the most precise measurement of neutral-current coherent $π^0$ production in the few-GeV neutrino energy region.

hep-ex↗

arXiv2020

Search for sterile neutrinos in MINOS and MINOS+ using a two-detector fit

A search for mixing between active neutrinos and light sterile neutrinos has been performed by looking for muon neutrino disappearance in two detectors at baselines of 1.04 km and 735 km, using a combined MINOS and MINOS+ exposure of $16.36\times10^{20}$ protons-on-target. A simultaneous fit to the charged-current muon neutrino and neutral-current neutrino energy spectra in the two detectors yields no evidence for sterile neutrino mixing using a 3+1 model. The most stringent limit to date is set on the mixing parameter $\sin^2θ_{24}$ for most values of the sterile neutrino mass-splitting $Δm^2_{41} > 10^{-4}$ eV$^2$.

hep-ex↗

arXiv2019

Observation of seasonal variation of atmospheric multiple-muon events in the NOvA Near Detector

Using two years of data from the NOvA Near Detector at Fermilab, we report a seasonal variation of cosmic ray induced multiple-muon event rates which has an opposite phase to the seasonal variation in the atmospheric temperature. The strength of the seasonal multipl$ increase as a function of the muon multiplicity. However, no significant dependence of the strength of the seasonal variation of the multiple-muon variation is seen as a function of the muon zenith angle, or the spatial or angular separation between the correlated muons.

physics.ins-det↗

arXiv2019

First measurement of neutrino oscillation parameters using neutrinos and antineutrinos by NOvA

The NOvA experiment has made a $4.4σ$-significant observation of $\barν_{e}$ appearance in a 2 GeV $\barν_μ$ beam at a distance of 810 km. Using $12.33\times10^{20}$ protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 $\barν_μ \rightarrow \barν_{e}$ candidates with a background of 10.3 and 102 $\barν_μ \rightarrow \barν_μ$ candidates. This new antineutrino data is combined with neutrino data to measure the oscillation parameters $|Δm^2_{32}| = 2.48^{+0.11}_{-0.06}\times10^{-3}$ eV$^2/c^4$, $\sin^2 θ_{23} = 0.56^{+0.04}_{-0.03}$ in the normal neutrino mass hierarchy and upper octant and excludes most values near $δ_{\rm CP}=π/2$ for the inverted mass hierarchy by more than 3$σ$. The data favor the normal neutrino mass hierarchy by 1.9$σ$ and $θ_{23}$ values in the upper octant by 1.6$σ$.

hep-ex↗

arXiv2018

New constraints on oscillation parameters from $ν_e$ appearance and $ν_μ$ disappearance in the NOvA experiment

We present updated results from the NOvA experiment for $ν_μ\rightarrowν_μ$ and $ν_μ\rightarrowν_e$ oscillations from an exposure of $8.85\times10^{20}$ protons on target, which represents an increase of 46% compared to our previous publication. The results utilize significant improvements in both the simulations and analysis of the data. A joint fit to the data for $ν_μ$ disappearance and $ν_e$ appearance gives the best fit point as normal mass hierarchy, $Δm^2_{32} = 2.44\times 10^{-3}{{\rm eV}^2}/c^4$, $\sin^2θ_{23} = 0.56$, and $δ_{CP} = 1.21π$. The 68.3% confidence intervals in the normal mass hierarchy are $Δm^2_{32} \in [2.37,2.52]\times 10^{-3}{{\rm eV}^2}/c^4$, $\sin^2θ_{23} \in [0.43,0.51] \cup [0.52,0.60]$, and $δ_{CP} \in [0,0.12π] \cup [0.91π,2π]$. The inverted mass hierarchy is disfavored at the 95% confidence level for all choices of the other oscillation parameters.

hep-ex↗

arXiv2017

Measurements and calculations of air activation in the NuMI neutrino production facility at Fermilab with the 120-GeV proton beam on target

Measurements and calculations of the air activation at a high-energy proton accelerator are described. The quantity of radionuclides released outdoors depends on operation scenarios including details of the air exchange inside the facility. To improve the prediction of the air activation levels, the MARS15 Monte Carlo code radionuclide production model was modified to be used for these studies. Measurements were done to benchmark the new model and verify its use in optimization studies for the new DUNE experiment at the Long Baseline Neutrino Facility (LBNF) at Fermilab. The measured production rates for the most important radionuclides - $^{11}$C, $^{13}$N, $^{15}$O and $^{41}$Ar - are in a good agreement with those calculated with the improved MARS15 code.

physics.acc-ph↗

arXiv2017

Search for active-sterile neutrino mixing using neutral-current interactions in NOvA

We report results from the first search for sterile neutrinos mixing with active neutrinos through a reduction in the rate of neutral-current interactions over a baseline of 810\,km between the NOvA detectors. Analyzing a 14-kton detector equivalent exposure of 6.05$\times$10$^{20}$ protons-on-target in the NuMI beam at Fermilab, we observe 95 neutral-current candidates at the Far Detector compared with $83.5 \pm 9.7 \mbox{(stat.)} \pm 9.4 \mbox{(syst.)}$ events predicted assuming mixing only occurs between active neutrino species. No evidence for $ν_μ \rightarrow ν_{s}$ transitions is found. Interpreting these results within a 3+1 model, we place constraints on the mixing angles $θ_{24}<20.8^{\circ}$ and $θ_{34}<31.2^{\circ}$ at the 90% C.L. for $0.05~eV^2\leq Δm^2_{41}\leq 0.5~eV^2$, the range of mass splittings that produce no significant oscillations over the Near Detector baseline.

hep-ex↗

arXiv2017

Measurements of $π^\pm$, K$^\pm$, p and $\bar{\textrm{p}}$ spectra in proton-proton interactions at 20, 31, 40, 80 and 158 GeV/c with the NA61/SHINE spectrometer at the CERN SPS

Measurements of inclusive spectra and mean multiplicities of $π^\pm$, K$^\pm$, p and $\bar{\textrm{p}}$ produced in inelastic p+p interactions at incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c ($\sqrt{s} = $ 6.3, 7.7, 8.8, 12.3 and 17.3 GeV, respectively) were performed at the CERN Super Proton Synchrotron using the large acceptance NA61/SHINE hadron spectrometer. Spectra are presented as function of rapidity and transverse momentum and are compared to predictions of current models. The measurements serve as the baseline in the NA61/SHINE study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter.

nucl-ex↗

arXiv2017

Constraints on Oscillation Parameters from $ν_e$ Appearance and $ν_μ$ Disappearance in NOvA

Results are reported from an improved measurement of $ν_μ\rightarrow ν_e$ transitions by the NOvA experiment. Using an exposure equivalent to $6.05\times10^{20}$ protons-on-target 33 $ν_e$ candidates were observed with a background of $8.2\pm0.8$ (syst.). Combined with the latest NOvA $ν_μ$ disappearance data and external constraints from reactor experiments on $\sin^22θ_{13}$, the hypothesis of inverted mass hierarchy with $θ_{23}$ in the lower octant is disfavored at greater than $93\%$ C.L. for all values of $δ_{CP}$.

hep-ex↗

arXiv2017

Measurement of Meson Resonance Production in $π^{-} + $C Interactions at SPS energies

We present measurements of $ρ^0$, $ω$ and K$^{*0}$ spectra in $π^{-} + $C production interactions at 158 GeV/c and $ρ^0$ spectra at 350 GeV/c using the NA61/SHINE spectrometer at the CERN SPS. Spectra are presented as a function of the Feynman's variable $x_\text{F}$ in the range $0 < x_\text{F} < 1$ and $0 < x_\text{F} < 0.5$ for 158 GeV/c and 350 GeV/c respectively. Furthermore, we show comparisons with previous measurements and predictions of several hadronic interaction models. These measurements are essential for a better understanding of hadronic shower development and for improving the modeling of cosmic ray air showers.

nucl-ex↗

arXiv2017

Measurement of the neutrino mixing angle $θ_{23}$ in NOvA

This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of $6.05\times10^{20}$ protons-on-target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal mixing ($θ_{23} = π/4$). Assuming the normal mass hierarchy, we find $Δm^2 = (2.67 \pm 0.11)\times 10^{-3}$ eV$^2$ and $\sin^2 θ_{23}$ at the two statistically degenerate values $0.404^{+0.030}_{-0.022}$ and $0.624^{+0.022}_{-0.030}$, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6 $σ$ significance.

hep-ex↗

arXiv2017

Design Of The LBNF Beamline

The Long Baseline Neutrino Facility (LBNF) will utilize a beamline located at Fermilab to provide and aim a neutrino beam of sufficient intensity and appropriate energy range toward the Deep Underground Neutrino Experiment (DUNE) detectors, placed deep underground at the SURF Facility in Lead, South Dakota. The primary proton beam (60-120 GeV) will be extracted from the MI-10 section of Fermilab's Main Injector. Neutrinos will be produced when the protons interact with a solid target to produce mesons which will be subsequently focused by magnetic horns into a 194m long decay pipe where they decay into muons and neutrinos. The parameters of the facility were determined taking into account the physics goals, spatial and radiological constraints, and the experience gained by operating the NuMI facility at Fermilab. The Beamline facility is designed for initial operation at a proton-beam power of 1.2 MW, with the capability to support an upgrade to 2.4 MW. LBNF/DUNE obtained CD-1 approval in November 2015. We discuss here the design status and the associated challenges as well as the R&D and plans for improvements before baselining the facility.

physics.acc-ph↗