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G. B. Mills

Publications and source records attributed to G. B. Mills.

At least 73 records · Page 4Linked to original sources
arXiv2011

Measurement of inclusive charged current interactions on carbon in a few-GeV neutrino beam

The SciBooNE Collaboration reports a measurement of inclusive charged current interactions of muon neutrinos on carbon with an average energy of 0.8 GeV using the Fermilab Booster Neutrino Beam. We compare our measurement with two neutrino interaction simulations: NEUT and NUANCE. The charged current interaction rates (product of flux and cross section) are extracted by fitting the muon kinematics, with a precision of 6-15% for the energy dependent and 3% for the energy integrated analyses. We also extract CC inclusive interaction cross sections from the observed rates, with a precision of 10-30% for the energy dependent and 8% for the energy integrated analyses. This is the first measurement of the CC inclusive cross section on carbon around 1 GeV. These results can be used to convert previous SciBooNE cross section ratio measurements to absolute cross section values.

hep-ex↗
arXiv2010

First Measurement of the Muon Neutrino Charged Current Quasielastic Double Differential Cross Section

A high-statistics sample of charged-current muon neutrino scattering events collected with the MiniBooNE experiment is analyzed to extract the first measurement of the double differential cross section ($\frac{d^2σ}{dT_μd\cosθ_μ}$) for charged-current quasielastic (CCQE) scattering on carbon. This result features minimal model dependence and provides the most complete information on this process to date. With the assumption of CCQE scattering, the absolute cross section as a function of neutrino energy ($σ[E_ν]$) and the single differential cross section ($\frac{dσ}{dQ^2}$) are extracted to facilitate comparison with previous measurements. These quantities may be used to characterize an effective axial-vector form factor of the nucleon and to improve the modeling of low-energy neutrino interactions on nuclear targets. The results are relevant for experiments searching for neutrino oscillations.

hep-ex↗
arXiv2010

Expression of Interest for a Novel Search for CP Violation in the Neutrino Sector: DAEdALUS

DAEdALUS, a Decay-At-rest Experiment for delta_CP studies At the Laboratory for Underground Science, provides a new approach to the search for CP violation in the neutrino sector. The design utilizes low-cost, high-power proton accelerators under development for commercial uses. These provide neutrino beams with energy up to 52 MeV from pion and muon decay-at-rest. The experiment searches for aninu_mu to antinu_e at short baselines corresponding to the atmospheric Delta m^2 region. The antinu_e will be detected, via inverse beta decay, in the 300 kton fiducial-volume Gd-doped water Cherenkov neutrino detector proposed for the Deep Underground Science and Engineering Laboratory (DUSEL). DAEdALUS opens new opportunities for DUSEL. It provides a high-statistics, low-background alternative for CP violation searches which matches the capability of the conventional long-baseline neutrino experiment, LBNE. Because of the complementary designs, when DAEdALUS antineutrino data are combined with LBNE neutrino data, the sensitivity of the CP-violation search improves beyond any present proposals, including the proposal for Project X. Also, the availability of an on-site neutrino beam opens opportunities for additional physics, both for the presently planned DUSEL detectors and for new experiments at a future 300 ft campus.

physics.ins-det↗
arXiv2010

Measurement of neutral current coherent neutral pion production on carbon in a few-GeV neutrino beam

The SciBooNE Collaboration reports a measurement of neutral current coherent neutral pion production on carbon by a muon neutrino beam with average energy 0.8 GeV. The separation of coherent from inclusive neutral pion production has been improved by detecting recoil protons from resonant neutral pion production. We measure the ratio of the neutral current coherent neutral pion production to total charged current cross sections to be (1.16 +/- 0.24) x 10-2. The ratio of charged current coherent pion to neutral current coherent pion production is calculated to be 0.14+0.30 -0.28, using our published charged current coherent pion measurement.

hep-ex↗
arXiv2010

Measurement of Inclusive Neutral Current Neutral Pion Production on Carbon in a Few-GeV Neutrino Beam

The SciBooNE Collaboration reports inclusive neutral current neutral pion production by a muon neutrino beam on a polystyrene target (C8H8). We obtain (7.7 \pm 0.5(stat.) \pm 0.5 (sys.)) x 10^(-2) as the ratio of the neutral current neutral pion production to total charged current cross section; the mean energy of neutrinos producing detected neutral pions is 1.1 GeV. The result agrees with the Rein-Sehgal model implemented in our neutrino interaction simulation program with nuclear effects. The spectrum shape of the neutral pion momentum and angle agree with the model. We also measure the ratio of the neutral current coherent pion production to total charged current cross section to be (0.7 \pm 0.4) x 10^(-2).

hep-ex↗
arXiv2010

Measurement of ν_μand \barν_μinduced neutral current single $π^0$ production cross sections on mineral oil at E_νO(1 GeV)

MiniBooNE reports the first absolute cross sections for neutral current single π^0 production on CH_2 induced by neutrino and antineutrino interactions measured from the largest sets of NC π^0 events collected to date. The principal result consists of differential cross sections measured as functions of π^0 momentum and π^0 angle averaged over the neutrino flux at MiniBooNE. We find total cross sections of (4.76+/-0.05_{stat}+/-0.76_{sys})*10^{-40} cm^2/nucleon at a mean energy of =808 MeV and (1.48+/-0.05_{stat}+/-0.23_{sys})*10^{-40} cm^2/nucleon at a mean energy of =664 MeV for ν_μand \barν_μinduced production, respectively. In addition, we have included measurements of the neutrino and antineutrino total cross sections for incoherent exclusive NC 1π^0 production corrected for the effects of final state interactions to compare to prior results.

hep-ex↗
arXiv2010

Large-angle production of charged pions with incident pion beams on nuclear targets

Measurements of the double-differential pi+/- production cross-section in the range of momentum 100 MeV/c <= p <= 800 MeV/c and angle 0.35 rad <= theta <= 2.15 rad using pi+/- beams incident on beryllium, aluminium, carbon, copper, tin, tantalum and lead targets are presented. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN Proton Synchrotron. The secondary pions were produced by beams in a momentum range from 3 GeV/c to 12.9 GeV/c hitting a solid target with a thickness of 5% of a nuclear interaction length. The tracking and identification of the produced particles was performed using a small-radius cylindrical time projection chamber (TPC) placed inside a solenoidal magnet. Incident particles were identified by an elaborate system of beam detectors. Results are obtained for the double-differential cross-sections d2sigma/dpdtheta at six incident beam momenta. Data at 3 GeV/c, 5 GeV/c, 8 GeV/c, and 12 GeV/c are available for all targets while additional data at 8.9 GeV/c and 12.9 GeV/c were taken in positive particle beams on Be and Al targets, respectively. The measurements are compared with several generators of GEANT4 and the MARS Monte Carlo simulation.

hep-ex↗
arXiv2009

Comparison of large-angle production of charged pions with incident protons on cylindrical long and short targets

The HARP collaboration has presented measurements of the double-differential pi+/pi- production cross-section in the range of momentum 100 MeV/c <= p 800 MeV/c and angle 0.35 rad <= theta <= 2.15 rad with proton beams hitting thin nuclear targets. In many applications the extrapolation to long targets is necessary. In this paper the analysis of data taken with long (one interaction length) solid cylindrical targets made of carbon, tantalum and lead is presented. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN PS. The secondary pions were produced by beams of protons with momenta 5 GeV/c, 8 GeV/c and 12 GeV/c. The tracking and identification of the produced particles were performed using a small-radius cylindrical time projection chamber (TPC) placed inside a solenoidal magnet. Incident protons were identified by an elaborate system of beam detectors. Results are obtained for the double-differential yields per target nucleon d2 sigma / dp dtheta. The measurements are compared with predictions of the MARS and GEANT4 Monte Carlo simulations.

hep-ex↗
arXiv2009

A Letter of Intent to Build a MiniBooNE Near Detector: BooNE

There is accumulating evidence for a difference between neutrino and antineutrino oscillations at the $\sim 1$ eV$^2$ scale. The MiniBooNE experiment observes an unexplained excess of electron-like events at low energies in neutrino mode, which may be due, for example, to either a neutral current radiative interaction, sterile neutrino decay, or to neutrino oscillations involving sterile neutrinos and which may be related to the LSND signal. No excess of electron-like events ($-0.5 \pm 7.8 \pm 8.7$), however, is observed so far at low energies in antineutrino mode. Furthermore, global 3+1 and 3+2 sterile neutrino fits to the world neutrino and antineutrino data suggest a difference between neutrinos and antineutrinos with significant ($\sin^22θ_{μμ} \sim 35%$) $\bar ν_μ$ disappearance. In order to test whether the low-energy excess is due to neutrino oscillations and whether there is a difference between $ν_μ$ and $\bar ν_μ$ disappearance, we propose building a second MiniBooNE detector at (or moving the existing MiniBooNE detector to) a distance of $\sim 200$ m from the Booster Neutrino Beam (BNB) production target. With identical detectors at different distances, most of the systematic errors will cancel when taking a ratio of events in the two detectors, as the neutrino flux varies as $1/r^2$ to a calculable approximation. This will allow sensitive tests of oscillations for both $ν_e$ and $\bar ν_e$ appearance and $ν_μ$ and $\bar ν_μ$ disappearance. Furthermore, a comparison between oscillations in neutrino mode and antineutrino mode will allow a sensitive search for CP and CPT violation in the lepton sector at short baseline ($Δm^2 > 0.1$ eV$^2$).

hep-ex↗
arXiv2009

First Measurement of $ν_μ$ and $ν_e$ Events in an Off-Axis Horn-Focused Neutrino Beam

We report the first observation of off-axis neutrino interactions in the MiniBooNE detector from the NuMI beamline at Fermilab. The MiniBooNE detector is located 745 m from the NuMI production target, at 110 mrad angle ($6.3^{\circ}$) with respect to the NuMI beam axis. Samples of charged current quasi-elastic $ν_μ$ and $ν_e$ interactions are analyzed and found to be in agreement with expectation. This provides a direct verification of the expected pion and kaon contributions to the neutrino flux and validates the modeling of the NuMI off-axis beam.

hep-ex↗
arXiv2009

Measurement of the ν_μcharged current π^+ to quasi-elastic cross section ratio on mineral oil in a 0.8 GeV neutrino beam

Using high statistics samples of charged current $ν_μ$ interactions, MiniBooNE reports a measurement of the single charged pion production to quasi-elastic cross section ratio on mineral oil (CH$_2$), both with and without corrections for hadron re-interactions in the target nucleus. The result is provided as a function of neutrino energy in the range 0.4 GeV $< E_ν<$ 2.4 GeV with 11% precision in the region of highest statistics. The results are consistent with previous measurements and the prediction from historical neutrino calculations.

hep-ex↗
arXiv2008

First Observation of Coherent $π^0$ Production in Neutrino Nucleus Interactions with $E_ν<$ 2 GeV

The MiniBooNE experiment at Fermilab has amassed the largest sample to date of $π^0$s produced in neutral current (NC) neutrino-nucleus interactions at low energy. This paper reports a measurement of the momentum distribution of $π^0$s produced in mineral oil (CH$_2$) and the first observation of coherent $π^0$ production below 2 GeV. In the forward direction, the yield of events observed above the expectation for resonant production is attributed primarily to coherent production off carbon, but may also include a small contribution from diffractive production on hydrogen. Integrated over the MiniBooNE neutrino flux, the sum of the NC coherent and diffractive modes is found to be (19.5 $\pm$1.1 (stat) $\pm$2.5 (sys))% of all exclusive NC $π^0$ production at MiniBooNE. These measurements are of immediate utility because they quantify an important background to MiniBooNE's search for $ν_μ \to ν_e$ oscillations.

hep-ex↗
arXiv2005

Tests of Lorentz violation in muon antineutrino to electron antineutrino oscillations

A recently developed Standard-Model Extension (SME) formalism for neutrino oscillations that includes Lorentz and CPT violation is used to analyze the sidereal time variation of the neutrino event excess measured by the Liquid Scintillator Neutrino Detector (LSND) experiment. The LSND experiment, performed at Los Alamos National Laboratory, observed an excess, consistent with neutrino oscillations, of ${\barν}_e$ in a beam of ${\barν}_μ$. It is determined that the LSND oscillation signal is consistent with no sidereal variation. However, there are several combinations of SME coefficients that describe the LSND data; both with and without sidereal variations. The scale of Lorentz and CPT violation extracted from the LSND data is of order $10^{-19}$ GeV for the SME coefficients $a_L$ and $E \times c_L$. This solution for Lorentz and CPT violating neutrino oscillations may be tested by other short baseline neutrino oscillation experiments, such as the MiniBooNE experiment.

hep-ex↗
arXiv2005

Measuring Active-Sterile Neutrino Oscillations with a Stopped Pion Neutrino Source

The question of the existence of light sterile neutrinos is of great interest in many areas of particle physics, astrophysics, and cosmology. Furthermore, should the MiniBooNE experiment at Fermilab confirm the LSND oscillation signal, then new measurements are required to identify the mechanism responsible for these oscillations. Possibilities include sterile neutrinos, CP or CPT violation, variable mass neutrinos, Lorentz violation, and extra dimensions. In this paper, we consider an experiment at a stopped pion neutrino source to determine if active-sterile neutrino oscillations with delta-m greater than 0.1 eV2 can account for the signal. By exploiting stopped pi+ decay to produce a monoenergetic nu_mu source, and measuring the rate of the neutral current reaction nu_x + 12C -> nu_x +12C* as a function of distance from the source, we show that a convincing test for active-sterile neutrino oscillations can be performed.

hep-ph↗
arXiv2003

Search for $π^0 \to ν_μ\barν_μ$ Decay in LSND

We observe a net beam-excess of $8.7 \pm 6.3$ (stat) $\pm 2.4$ (syst) events, above 160 MeV, resulting from the charged-current reaction of $ν_μ$ and/or $\barν_μ$ on C and H in the LSND detector. No beam related muon background is expected in this energy regime. Within an analysis framework of $π^0 \to ν_μ\barν_μ$, we set a direct upper limit for this branching ratio of $Γ(π^0 \to ν_μ\barν_μ) / Γ(π^0 \to all) < 1.6 \times 10^{-6}$ at 90% confidence level.

hep-ex↗
arXiv2002

Statistical Analysis of Different Muon-antineutrino->Electron-antineutrino Searches

A combined statistical analysis of the experimental results of the LSND and KARMEN \numubnueb oscillation search is presented. LSND has evidence for neutrino oscillations that is not confirmed by the KARMEN experiment. This joint analysis is based on the final likelihood results for both data sets. A frequentist approach is applied to deduce confidence regions. At a combined confidence level of 36%, there is no area of oscillation parameters compatible with both experiments. For the complementary confidence of 1-0.36=64%, there are two well defined regions of oscillation parameters (sin^2(2th),Dm^2) compatible with both experiments.

hep-ex↗
arXiv2001

Measurements of Charged Current Reactions of $ν_e$ on $^{12}C$

Charged Current reactions of $ν_e$ on $^{12}C$ have been studied using a $μ^+$ decay-at-rest $ν_e$ beam at the Los Alamos Neutron Science Center. The cross section for the exclusive reaction $^{12}C(ν_e,e^-)^{12}N_{g.s.}$ was measured to be $(8.9\pm0.3\pm0.9)\times10^{-42}$ cm$^2$. The observed energy dependence of the cross section and angular distribution of the outgoing electron agree well with theoretical expectations. Measurements are also presented for inclusive transitions to $^{12}N$ excited states, $^{12}C(ν_e,e^-)^{12}N^*$ and compared with theoretical expectations. The measured cross section, $(4.3\pm0.4\pm0.6)\times10^{-42}$ cm$^2$, is somewhat lower than previous measurements and than a continuum random phase approximation calculation. It is in better agreement with a recent shell model calculation.

hep-ex↗