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R. Bernstein

Publications and source records attributed to R. Bernstein.

36 records · Page 2Linked to original sources
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↗
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

Expression of Interest for Evolution of the Mu2e Experiment

We propose an evolution of the Mu2e experiment, called Mu2e-II, that would leverage advances in detector technology and utilize the increased proton intensity provided by the Fermilab PIP-II upgrade to improve the sensitivity for neutrinoless muon-to-electron conversion by one order of magnitude beyond the Mu2e experiment, providing the deepest probe of charged lepton flavor violation in the foreseeable future. Mu2e-II will use as much of the Mu2e infrastructure as possible, providing, where required, improvements to the Mu2e apparatus to accommodate the increased beam intensity and cope with the accompanying increase in backgrounds.

physics.ins-det↗
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

The Single-Phase ProtoDUNE Technical Design Report

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.

physics.ins-det↗
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 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↗
arXiv2016

First measurement of electron neutrino appearance in NOvA

We report results from the first search for $ν_μ\toν_e$ transitions by the NOvA experiment. In an exposure equivalent to $2.74\times10^{20}$ protons-on-target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of $0.99\pm0.11$ (syst.) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of $1.07\pm0.14$ (syst.). The $3.3σ$ excess of events observed in the primary analysis disfavors $0.1π< δ_{CP} < 0.5π$ in the inverted mass hierarchy at the 90% C.L.

hep-ex↗
arXiv2016

Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 1: The LBNF and DUNE Projects

This document presents the Conceptual Design Report (CDR) put forward by an international neutrino community to pursue the Deep Underground Neutrino Experiment at the Long-Baseline Neutrino Facility (LBNF/DUNE), a groundbreaking science experiment for long-baseline neutrino oscillation studies and for neutrino astrophysics and nucleon decay searches. The DUNE far detector will be a very large modular liquid argon time-projection chamber (LArTPC) located deep underground, coupled to the LBNF multi-megawatt wide-band neutrino beam. DUNE will also have a high-resolution and high-precision near detector.

physics.ins-det↗
arXiv2016

First measurement of muon-neutrino disappearance in NOvA

This paper reports the first measurement using the NOvA detectors of $ν_μ$ disappearance in a $ν_μ$ beam. The analysis uses a 14 kton-equivalent exposure of $2.74 \times 10^{20}$ protons-on-target from the Fermilab NuMI beam. Assuming the normal neutrino mass hierarchy, we measure $Δm^{2}_{32}=(2.52^{+0.20}_{-0.18})\times 10^{-3}$ eV$^{2}$ and $\sin^2θ_{23}$ in the range 0.38-0.65, both at the 68% confidence level, with two statistically-degenerate best fit points at $\sin^2θ_{23} = $ 0.43 and 0.60. Results for the inverted mass hierarchy are also presented.

hep-ex↗
arXiv2014

Combining Dark Energy Survey Science Verification Data with Near Infrared Data from the ESO VISTA Hemisphere Survey

We present the combination of optical data from the Science Verification phase of the Dark Energy Survey (DES) with near infrared data from the ESO VISTA Hemisphere Survey (VHS). The deep optical detections from DES are used to extract fluxes and associated errors from the shallower VHS data. Joint 7-band ($grizYJK$) photometric catalogues are produced in a single 3 sq-deg DECam field centred at 02h26m$-$04d36m where the availability of ancillary multi-wavelength photometry and spectroscopy allows us to test the data quality. Dual photometry increases the number of DES galaxies with measured VHS fluxes by a factor of $\sim$4.5 relative to a simple catalogue level matching and results in a $\sim$1.5 mag increase in the 80\% completeness limit of the NIR data. Almost 70\% of DES sources have useful NIR flux measurements in this initial catalogue. Photometric redshifts are estimated for a subset of galaxies with spectroscopic redshifts and initial results, although currently limited by small number statistics, indicate that the VHS data can help reduce the photometric redshift scatter at both $z<0.5$ and $z>1$. We present example DES+VHS colour selection criteria for high redshift Luminous Red Galaxies (LRGs) at $z\sim0.7$ as well as luminous quasars. Using spectroscopic observations in this field we show that the additional VHS fluxes enable a cleaner selection of both populations with $<$10\% contamination from galactic stars in the case of spectroscopically confirmed quasars and $<0.5\%$ contamination from galactic stars in the case of spectroscopically confirmed LRGs. The combined DES+VHS dataset, which will eventually cover almost 5000 sq-deg, will therefore enable a range of new science and be ideally suited for target selection for future wide-field spectroscopic surveys.

astro-ph.CO↗
arXiv2012

Fundamental Physics at the Intensity Frontier

The Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms.

hep-ex↗
arXiv2007

The Interstellar Medium of GRB Host Galaxies I. Echelle Spectra of Swift GRB Afterglows

We present optical echelle spectra of four gamma-ray burst (GRB) afterglows (GRB 050730, GRB 050820, GRB 051111, and GRB 060418) discovered during the first 1.5 years of operation of the Swift satellite and localized by either the Swift telescope or follow-up ground-based imaging. We analyze the spectra to derive accurate column density measurements for the transitions arising in the interstellar medium (ISM) of the GRB host galaxies. These measurements can be used to constrain the physical properties of the ISM including the metallicity, dust-to-gas ratio, ionization state, and chemical abundances of the gas. We also present measurements of the strong MgII systems in the GRB afterglow spectra. With the publication of this paper, we provide the first data release of echelle afterglow spectra by the GRAASP collaboration to the general community.

astro-ph↗
arXiv2000

Physics at a Neutrino Factory

In response to the growing interest in building a Neutrino Factory to produce high intensity beams of electron- and muon-neutrinos and antineutrinos, in October 1999 the Fermilab Directorate initiated two six-month studies. The first study, organized by N. Holtkamp and D. Finley, was to investigate the technical feasibility of an intense neutrino source based on a muon storage ring. This design study has produced a report in which the basic conclusion is that a Neutrino Factory is technically feasible, although it requires an aggressive R&D program. The second study, which is the subject of this report, was to explore the physics potential of a Neutrino Factory as a function of the muon beam energy and intensity, and for oscillation physics, the potential as a function of baseline.

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