Search for Sterile Neutrinos in MINOS and MINOS+ Using a Two-Detector Fit
Not Available
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Engineering topics
Ling, J.
Publications and source records attributed to Ling, J..
The Intermediate Neutrino Program
The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Search for flavor-changing nonstandard neutrino interactions using $\nu_{e}$ appearance in MINOS
We report new constraints on flavor-changing nonstandard neutrino interactions from the MINOS long-baseline experiment using νe and ν¯e appearance candidate events from predominantly νμ and ν¯μ beams. We used a statistical selection algorithm to separate νe candidates from background events, enabling an analysis of the combined MINOS neutrino and antineutrino data. We observe no deviations from standard neutrino mixing, and thus place constraints on the nonstandard interaction matter effect, |ϵeτ|, and phase, (δCP+δeτ), using a 30-bin likelihood fit.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Constraints on Large Extra Dimensions from the MINOS Experiment
We report new constraints on the size of large extra dimensions from data collected by the MINOS experiment between 2005 and 2012. Our analysis employs a model in which sterile neutrinos arise as Kaluza-Klein states in large extra dimensions and thus modify the neutrino oscillation probabilities due to mixing between active and sterile neutrino states. Using Fermilab’s Neutrinos at the Main Injector beam exposure of 10.56×1020 protons on target, we combine muon neutrino charged current and neutral current data sets from the Near and Far Detectors and observe no evidence for deviations from standard three-flavor neutrino oscillations. The ratios of reconstructed energy spectra in the two detectors constrain the size of large extra dimensions to be smaller than 0.45 μm at 90% C.L. in the limit of a vanishing lightest active neutrino mass. Stronger limits are obtained for nonvanishing masses.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Measurement of single $\pi^0$ production by coherent neutral-current $\nu$ Fe interactions in the MINOS Near Detector
Forward single π0 production by coherent neutral-current interactions, νA→νAπ0, is investigated using a 2.8×1020 protons-on-target exposure of the MINOS Near Detector. For single-shower topologies, the event distribution in production angle exhibits a clear excess above the estimated background at very forward angles for visible energy in the range 1–8 GeV. Cross sections are obtained for the detector medium comprised of 80% iron and 20% carbon nuclei with ⟨A⟩=48, the highest-⟨A⟩ target used to date in the study of this coherent reaction. The total cross section for coherent neutral-current single π0 production initiated by the νμ flux of the NuMI low-energy beam with mean (mode) Eν of 4.9 GeV (3.0 GeV), is 77.6±5.0(stat)-16.8+15.0(syst)×10-40 cm2 pernucleus. The results are in good agreement with predictions of the Berger-Sehgal model.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Search for Sterile Neutrinos Mixing with Muon Neutrinos in MINOS
We report results of a search for oscillations involving a light sterile neutrino over distances of 1.04 and 735 km in a νμ-dominated beam with a peak energy of 3 GeV. The data, from an exposure of 10.56×1020 protons on target, are analyzed using a phenomenological model with one sterile neutrino. We constrain the mixing parameters θ24 and Δm412 and set limits on parameters of the four-dimensional Pontecorvo-Maki-Nakagawa-Sakata matrix, |Uμ4|2 and |Uτ4|2, under the assumption that mixing between νe and νs is negligible (|Ue4|2=0). No evidence for νμ→νs transitions is found and we set a world-leading limit on θ24 for values of Δm412≲1 eV2.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Cosmogenic backgrounds to $0νββ$ in EXO-200
As neutrinoless double-beta decay experiments become more sensitive and intrinsic radioactivity in detector materials is reduced, previously minor contributions to the background must be understood and eliminated. With this in mind, cosmogenic backgrounds have been studied with the EXO-200 experiment. Using the EXO-200 TPC, the muon flux (through a flat horizontal surface) underground at the Waste Isolation Pilot Plant (WIPP) has been measured to be $Φ$ = 4.07±0.14 (sys)±0.03 (stat)×10 -7 cm -2 s -1 , with a vertical intensity of $I_v$ = 2.97+0.14-0.13 (sys) ± 0.02 (stat) × 10 -7 cm -2 s -1 sr -1 . Simulations of muon-induced backgrounds identified several potential cosmogenic radionuclides, though only 137 Xe is a significant background for the 136 Xe $0νββ$ search with EXO-200. Muon-induced neutron backgrounds were measured using $γ$-rays from neutron capture on the detector materials. This provided a measurement of 137 Xe yield, and a test of the accuracy of the neutron production and transport simulations. The independently measured rates of 136 Xe neutron capture and of 137 Xe decay agree within uncertainties. Geant4 and FLUKA simulations were performed to estimate neutron capture rates, and these estimates agreed to within ~ 40% or better with measurements. The ability to identify 136 Xe($n,γ$) events will allow for rejection of 137 Xe backgrounds in future $0νββ$ analyses.
79 ASTRONOMY AND ASTROPHYSICS↗
First Search for Lorentz and CPT Violation in Double Beta Decay with EXO-200
Abstract Not Provided
Phenomenology-HEP, Experiment-Nucl,HEPPH↗
Measurement of the Multiple-Muon Charge Ratio in the MINOS Far Detector
The charge ratio, Rμ=Nμ+/Nμ-, for cosmogenic multiple-muon events observed at an underground depth of 2070 mwe has been measured using the magnetized MINOS Far Detector. The multiple-muon events, recorded nearly continuously from August 2003 until April 2012, comprise two independent data sets imaged with opposite magnetic field polarities, the comparison of which allows the systematic uncertainties of the measurement to be minimized. The multiple-muon charge ratio is determined to be Rμ=1.104±0.006(stat)-0.010+0.009(syst). This measurement complements previous determinations of single-muon and multiple-muon charge ratios at underground sites and serves to constrain models of cosmic-ray interactions at TeV energies.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Search for 2 ν β β decay of Xe 136 to the 0 1 + excited state of Ba 136 with the EXO-200 liquid xenon detector
EXO-200 is a single phase liquid xenon detector designed to search for neutrinoless ββ decay of 136 Xe to the ground state of 136 Ba. We report here on a search for the two-neutrino ββ decay of 136 Xe to the first 0 + excited state, 0 + 1 , of Ba136 based on a 100 kg yr exposure of 136 Xe. Using a specialized analysis employing a machine learning algorithm, we obtain a 90% CL half-life sensitivity of 1.7×10 24 yr. We find no statistically significant evidence for the 2νββ decay to the excited state resulting in a lower limit of T 2ν 1/2 (0 + → 0 + 1 ) > 6.9 ×10 23 yr at 90% CL. In conclusion, this observed limit is consistent with the estimated half-life of 2.5×10 25 yr.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Monitoring the Low-Energy Gamma-Ray Sky Using Earth Occultation with GLAST GBM
Long term all-sky monitoring of the 20 keV - 2 MeV gamma-ray sky using the Earth occultation technique was demonstrated by the BATSE instrument on the Compton Gamma Ray Observatory. The principles and techniques used for the development of an end-to-end earth occultation data analysis system for BATSE can be extended to the GLAST Gamma-ray Burst Monitor (GBM), resulting in multiband light curves and time-resolved spectra in the energy range 8 keV to above 1 MeV for known gamma-ray sources and transient outbursts, as well as the discovery of new sources of gamma-ray emission. In this paper we describe the application of the technique to the GBM. We also present the expected sensitivity for the GBM.
Case, G.↗
A review of Cygnus X-1 soft gamma-ray observations
This paper provides a brief summary of some of the important long-term temporal and spectral results obtained over the last thirty years, and discusses the current status and issues that need to be addressed by upcoming missions.
x-ray sources black holes↗
Hard X-ray spectra of neutron stars and black hole candidates
The hard X-ray behavior of several X-ray binary systems containing a neutron star or a black hole candidate is analyzed in an attempt to determine the specific signature of these categories of compact objects. Limiting the consideration to two subclasses of neutron stars, Atoll sources and non-pulsating Z sources, it appears that only the Atoll sources have a spectral behavior similar to black holes. It is proposed that Atoll sources are weakly magnetized neutron stars, whereas Z sources are small radius moderate magnetized neutron stars. Large magnetic fields funnel the accreting matter, thus preventing spherical accretion and free fall if the neutron star radius is smaller than the last stable accreting orbit. Weak magnetic fields do not have this effect, and blackbody soft photons from the stellar surface are upscattered on the relativistic infalling matter, leading to excess hard X-rays. This excess is visible in two of the observed Atoll sources and in the spectrum of a black hole candidate. In the case of a Z source, a lack of photons was remarked, providing a possible signature to distinguish between these classes of objects.
Durouchoux, P.↗
Multi-Parameter Linear Least-Squares Fitting to Poisson Data One Count at a Time
A standard problem in gamma-ray astronomy data analysis is the decomposition of a set of observed counts, described by Poisson statistics, according to a given multi-component linear model, with underlying physical count rates or fluxes which are to be estimated from the data.
gamma-rays: general numerical methods↗
Modulation Collimator Fine Grids for HESP
The proposed High Engergy-Solar Physics (HESP) million will require fine, precise, high aspect ratio modulation collimators for the High Energy Imagin Spectrometer (HEISPEC). The fabrication approach described here rests on the proven precision of semiconductor lithography - the ability to replicate extremely accurate patterns onto different planar substrateds.
LIGA HESP pitch structures solar x-rays gamma rays↗
HEAO 3 Observations of the Galactic Center 511 keV Line
This paper describes improved analysis algorithms which enabled HEAO 3 data to be reexamined for an assumed point source at the Galactic center.
gamma-rays↗
Measurement of the local density spectrum
Since there is still disagreement among the results of various groups, a measurement of the local density spectrum with a close-packed array of four scintillators, each of area 0.14 sq cm was made. Data are taken with conventional electronics, supervised by an on-line microcomputer. The data are stored on audio cassettes and analyzed with the aid of another microcomputer. Since four independent samples for each shower are available, uncertainties inherent in results from many earlier experiments can be minimized.
Liu, Z. H.↗
Measurement of muon intensity by Cerenkov method
Optical detection is an important technique in studies and observations of air showers, muons and relevant phenomena. The muon intensity is measured in a proper energy range and to study some problems about Cerenkov radiation of cosmic rays are studied, by a muon-telescope operated with Cerenkov detector. It is found that the measured muon intensity agrees with the integral energy spectrum of cosmic ray muons.
Liu, Z. H.↗