[en] The Sudbury Neutrino Observatory consists of a 1 kiloton heavy water Cherenkov detector able to detect and reconstruct high-energy muons created from cosmic ray showers and atmospheric neutrino interactions. By measuring the flux of through-going muons as a function of zenith angle, the SNO experiment can distinguish between the oscillated and un-oscillated portion of the neutrino flux. This report describes SNO's measurements of the flux of cosmic ray muons and neutrino-induced muon flux at a depth of 5890 meters water equivalent.

[en] Remarkable progress has been made over the past 30 years in understanding the flux of neutrinos coming from the sun. The so-called 'solar neutrino puzzle', whereby the total number of electron neutrinos from the sun does not match the expected total neutrino yield can be now understood in the context of neutrino flavor transformations. The Sudbury Neutrino Observatory has contributed to understanding the solar neutrino problem by measuring both the electron and non-electron components of the solar neutrino flux. The Sudbury Neutrino Observatory is a 1000 T D2O Cerenkov detector that is sensitive to 8B neutrinos produced in the sun. By using the energy, radius, and direction with respect to the sun, the SNO experiment can separately determine the rates of the charged current, neutral current and electron scattering reactions of neutrinos on deuterium. Assuming an undistorted 8B spectrum, the ve component of the 8B solar flux is φ_e 1.76_-0.05^+0.05(stat.)_-0.09^+0.09 (syst.) x 10⁶ cm^-2s^-1 based on events with a measured kinetic energy above 5 MeV. The non-ve component is φ_μτ 3.41_-0.45^+0.45(stat.)_-0.45^+0.48 (syst.) x 10⁶ cm^-2s^-1, 5.3σ greater than zero, providing strong evidence for solar ve flavor transformation. The total flux measured with the NC reaction is φ_NC = 5.09_-0.43^+0.44(stat.)_-0.43^+0.46 (syst.) x 10⁶ cm^-2s^-1, consistent with the Standard Solar Model. A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the Large Mixing Angle (LMA) solution

[en] The shape of the beta decay energy distribution is sensitive to the mass of the electron neutrino. Attempts to measure the endpoint shape of tritium decay have so far seen no distortion from the zero-mass form. Here we show that a new type of electron energy spectroscopy could improve future measurements of this spectrum and therefore of the neutrino mass. We propose to detect the coherent cyclotron radiation emitted by an energetic electron in a magnetic field. For mildly relativistic electrons, like those in tritium decay, the relativistic shift of the cyclotron frequency allows us to extract the electron energy from the emitted radiation. As the technique inherently involves the measurement of a frequency in a non-destructive manner, it can, in principle, achieve a high degree of resolution and accuracy.

[en] The neutrino flux from the sun is predicted to have a CNO-cycle contribution as well as the known pp-chain component. Previously, only the fluxes from β⁺ decays of ¹³N, ¹⁵O, and ¹⁷F have been calculated in detail. Another neutrino component that has not been widely considered is electron capture on these nuclei. We calculate the number of interactions in several solar neutrino detectors due to neutrinos from electron capture on ¹³N, ¹⁵O, and ¹⁷F, within the context of the standard solar model. We also discuss possible nonstandard models where the CNO flux is increased

[en] The KATRIN experiment is a next-generation tritium beta decay experiment aimed at measuring the mass of the electron neutrino. KATRIN can also serve as a possible target for the process of neutrino capture, ν_e+³H→³He⁺+e⁻. The latter process is sensitive to the Cosmic Neutrino Background (CνB). The KATRIN experiment is sensitive to a CνB overdensity ratio of 2.0×10⁹ over standard concordance model predictions at 90% C.L. Ref: (arXiv:1006.1886v1)

[en] The Sudbury Neutrino Observatory (SNO) is a multi-phase experiment designed to measure both the electron and total active neutrino flux corning from the sun. During the first phase of the experiment (the pure D2O phase), it was definitively shown that neutrinos from the sun change flavors as they travel to the Earth. In this report, results from these measurements and the current status of the SNO detector are presented

[en] High energy muons and neutrinos are produced by the interaction of primary cosmic rays in the Earth's upper atmosphere. These primary interactions produce mesons which decay into muons and neutrinos. SNO is in a unique position amongst world experiments located underground. At the depth of over 6 km water equivalent, it is the deepest underground laboratory currently in operation. SNO can make a number of important measurements using muons. First, SNO is sensitive to the downward muon rate coming from primary cosmic ray interactions. Second, SNO's depth allows for a measurement of atmospheric neutrinos (via the detection of neutrino-induced muons) at inclinations as large as cos(θ_zenith)∼0.4. Although SNO is a modest-size Cherenkov detector, its unique niche allows it to make important model-independent checks of atmospheric neutrino oscillations as well as measurements for cosmic rays and muon spallation

[en] The KArlsruhe TRItium Neutrino experiment (KATRIN) combines an ultra-luminous molecular tritium source with an integrating high-resolution spectrometer to gain sensitivity to the absolute mass scale of neutrinos. The projected sensitivity of the experiment on the electron neutrino mass is 200 meV at 90% C.L. With such unprecedented resolution, the experiment is also sensitive to physics beyond the Standard Model, particularly to the existence of additional sterile neutrinos at the eV mass scale. A recent analysis of available reactor data appears to favor the existence of such a sterile neutrino with a mass splitting of |Δm_sterile|²⩾1.5 eV² and mixing strength of sin²2θ_sterile=0.17±0.08 at 95% C.L. Upcoming tritium beta decay experiments should be able to rule out or confirm the presence of the new phenomenon for a substantial fraction of the allowed parameter space.

[en] We report on the extraction of the structure functions F₂ and ΔxF₃=xF₃^ν-xF₃^ν-bar from CCFR ν_μ-Fe and ν-bar_μ-Fe differential cross sections. The extraction is performed in a physics model independent (PMI) way. This first measurement for ΔxF₃, which is useful in testing models of heavy charm production, is higher than current theoretical predictions. The F₂ (PMI) values measured in ν_μ and μ scattering are in good agreement with the predictions of Next to Leading Order PDFs (using massive charm production schemes), thus resolving the long-standing discrepancy between the two sets of data

[en] The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted ⁸B spectrum, the night minus day rate is 14.0%±6.3%^+1.5_-1.4 % of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the ν_e asymmetry is found to be 7.0%±4.9%^+1.3_-1.2% . A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution