First Observation of Coherent π0\pi^0 Production in Neutrino Nucleus Interactions with Eν<E_{\nu}< 2 GeV

The MiniBooNE experiment at Fermilab has amassed the largest sample to date of $\pi^0$s produced in neutral current (NC) neutrino-nucleus interactions at low energy. This paper reports a measurement of the momentum distribution of $\pi^0$s produced in mineral oil (CH$_2$) and the first observation of coherent $\pi^0$ 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 $\pi^0$ production at MiniBooNE. These measurements are of immediate utility because they quantify an important background to MiniBooNE's search for $\nu_{\mu} \to \nu_e$ oscillations.Comment: Submitted to Phys. Lett.

Test of Lorentz and CPT violation with Short Baseline Neutrino Oscillation Excesses

The sidereal time dependence of MiniBooNE electron neutrino and anti-electron neutrino appearance data are analyzed to search for evidence of Lorentz and CPT violation. An unbinned Kolmogorov-Smirnov test shows both the electron neutrino and anti-electron neutrino appearance data are compatible with the null sidereal variation hypothesis to more than 5%. Using an unbinned likelihood fit with a Lorentz-violating oscillation model derived from the Standard Model Extension (SME) to describe any excess events over background, we find that the electron neutrino appearance data prefer a sidereal time-independent solution, and the anti-electron neutrino appearance data slightly prefer a sidereal time-dependent solution. Limits of order 10E-20 GeV are placed on combinations of SME coefficients. These limits give the best limits on certain SME coefficients for muon neutrino to electron neutrino and anti-muon neutrino to anti-electron neutrino oscillations. The fit values and limits of combinations of SME coefficients are provided.Comment: 14 pages, 3 figures, and 2 tables, submitted to Physics Letters

Measurement of K(+) production cross section by 8 GeV protons using high-energy neutrino interactions in the SciBooNE detector

The SciBooNE Collaboration reports K[superscript +] production cross section and rate measurements using high-energy daughter muon neutrino scattering data off the SciBar polystyrene (C[subscript 8]H[subscript 8]) target in the SciBooNE detector. The K[superscript +] mesons are produced by 8 GeV protons striking a beryllium target in Fermilab Booster Neutrino Beam line (BNB). Using observed neutrino and antineutrino events in SciBooNE, we measure d[superscript 2]σ/dpdΩ=(5.34±0.76)  mb/(GeV/c×sr) for p+Be→K[superscript +]+X at mean K[superscript +] energy of 3.9 GeV and angle (with respect to the proton beam direction) of 3.7 degrees, corresponding to the selected K[superscript +] sample. Compared to Monte Carlo predictions using previous higher energy K[superscript +] production measurements, this measurement, which uses the NUANCE neutrino interaction generator, is consistent with a normalization factor of 0.85±0.12. This agreement is evidence that the extrapolation of the higher energy K[superscript +] measurements to an 8 GeV beam energy using Feynman scaling is valid. This measurement reduces the error on the K[superscript +] production cross section from 40% to 14%.Japan. Ministry of Education, Culture, Sports, Science and TechnologyJapan Society for the Promotion of ScienceJapan Society for the Promotion of Science (Grant-in-Aid for Scientific Research A 19204026)Japan Society for the Promotion of Science (Young Scientists S 20674004)Japan Society for the Promotion of Science (Young Scientists B 18740145