Unexplained excess of electronlike events from a 1-GeV neutrino beam.
نویسندگان
چکیده
The MiniBooNE Collaboration observes unexplained electronlike events in the reconstructed neutrino energy range from 200 to 475 MeV. With 6.46x10;{20} protons on target, 544 electronlike events are observed in this energy range, compared to an expectation of 415.2+/-43.4 events, corresponding to an excess of 128.8+/-20.4+/-38.3 events. The shape of the excess in several kinematic variables is consistent with being due to either nu_{e} and nu[over ]_{e} charged-current scattering or nu_{mu} neutral-current scattering with a photon in the final state. No significant excess of events is observed in the reconstructed neutrino energy range from 475 to 1250 MeV, where 408 events are observed compared to an expectation of 385.9+/-35.7 events.
منابع مشابه
New MiniBooNE Results
New results from the re-analysis of low energy excess from the Booster beam line and the results from measurements of neutrino interactions from NuMI beam line are discussed. MiniBooNE observes an unexplained excess of 128.8 ± 20.4 ± 38.3 electron-like events in the energy region 200 < Eν < 475 MeV. The NuMI data sample currently has a large systematic errors associated with νe events, but show...
متن کاملThe Golden Channel at a Neutrino Factory revisited: improved sensitivities from a Magnetised Iron Neutrino Detector
This paper describes the performance and sensitivity to neutrino mixing parameters of a Magnetised Iron Neutrino Detector (MIND) at a Neutrino Factory with a neutrino beam created from the decay of 10 GeV muons. Specifically, it is concerned with the ability of such a detector to detect muons of the opposite sign to those stored (wrong-sign muons) while suppressing contamination of the signal f...
متن کاملComment on the possible electron neutrino excess in the Super-Kamiokande atmospheric neutrino experiment
We investigate the implications of a possible excess of the electron neutrino events in the Super-Kamiokande atmospheric neutrino experiment. The excess, if real, leads to constraints on the νμ ↔ νe, νμ ↔ ντ and νe ↔ ντ oscillation parameters. Specifically, the excess implies that νe − νμ and νμ − ντ mixings are large whereas νe − ντ mixing is small. We show that the electron neutrino excess fa...
متن کاملK2k (kek to Kamioka) Neutrino-oscillation Experiment at Kek-ps * )
In recent years, several underground neutrino observatories 1) 3) have reported that the atmospheric neutrino ratio, R ≡ (νμ + ν̄μ)/(νe + ν̄e), is significantly smaller than the theoretical expectations. This “atmospheric neutrino anomaly” can be explained by a neutrino oscillation hypothesis with an oscillation parameter region of ∆m2 ∼ 10−2eV2 and sin 2θ ∼ 1. The atmospheric neutrino anomaly ha...
متن کاملTesting the Solar Neutrino Conversion with Atmospheric Neutrinos
Neutrino oscillations with parameters relevant for the large mixing solution of the solar neutrino problem (∆m21 = (2 − 20) · 10−5 eV2, sin 2θ12 > 0.65) can lead to observable (up to 10 12 %) excess of the e-like events in the sub-GeV atmospheric neutrino sample. The excess has a weak zenith angle dependence in the low energy part of the sample and strong zenith angle dependence in the high ene...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 102 10 شماره
صفحات -
تاریخ انتشار 2009