Recent Results From the K2K (KEK-to-Kamioka) Neutrino Oscillation Experiment
نویسنده
چکیده
For many years experiments studying neutrinos produced in interactions of cosmic rays with atmospheric nuclei have been measuring a significant suppression of the ratio of νμ to νe with respect to the expectation derived from standard hadronic shower models [1–6]. The popular interpretation of this suppression is that neutrino oscillations, in which νμ change to some other neutrino flavour in flight, are occurring. Neutrino oscillations can only take place if the neutrino has a finite mass and if, as in the quark sector, the neutrino mass eigenstates are not the same the flavour eigenstates. The probabilty of a neutrino with energy Eν(GeV) produced a distance L(km) from a detector to oscillate into another flavour is expressed (in the two-flavour approximation) as :
منابع مشابه
K2k (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 کاملLatest Results from the K2k Experiment A
The KEK to Kamioka long-baseline neutrino experiment (K2K) is the first accelerator-based experiment with hundreds of km neutrino path length. K2K focuses on the study of the existence of neutrino oscillations in νμ disappearance that is observed in atmospheric neutrinos. With nearly pure muon neutrino beam produced with 5.6 × 10 protons from 12 GeV PS on target, 56 neutrino events have been ob...
متن کاملLatest Results from K2k A
The possible existence of neutrino masses is the first signal beyond the standard model, which suggests grand unification. The KEK-to-Kamioka long-baseline neutrino experiment (K2K) 1 is motivated by the atmospheric neutrino anomaly found by the Kamiokande experiment . One possible explanation of the anomaly is neutrino oscillation. Later, the Super–Kamiokande (SK) group confirmed the deficit o...
متن کاملCurrent Status of the K2k Long-baseline Neutrino-oscillation Experiment
The K2K (KEK to Kamioka) long-baseline neutrino-oscillation experiment was successfully started in early 1999. A total intensity of 7.20 × 10 protons on target, which is about 7% of the goal of the experiment, was accumulated in 39.4 days of data-taking in 1999. We obtained 3 neutrino events in the fiducial volume of the Super-Kamiokande detector, whereas the expectation based on observations i...
متن کامل0 The First Results of K 2 K long - baseline Neutrino Oscillation Experiment
The first results of the K2K(KEK to Kamioka) long-baseline neutrino oscillation experiment are presented in this talk. In 1999 7.2×10 18 protons on target were delivered to the experiment. During this period of running there were 3 events fully contained in the Super-Kamiokande inner detector fiducial area which occurred during the beam spill timing window. In the case of no oscillations the ex...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2000