Observations of neutral-current ν interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current, elastic scattering, and charged current reactions and assuming the standard 8 B shape, the

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 nu(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.

Solar neutrinos from (8)B decay have been detected at the Sudbury Neutrino Observatory via the charged current (CC) reaction on deuterium and the elastic scattering (ES) of electrons. The flux of nu(e)'s is measured by the CC reaction rate to be straight phi(CC)(nu(e)) = 1.75 +/- 0.07(stat)(+0.12)(-0.11)(syst) +/- 0.05(theor) x 10(6) cm(-2) s(-1). Comparison of straight phi(CC)(nu(e)) to the Super-Kamiokande Collaboration's precision value of the flux inferred from the ES reaction yields a 3.3 sigma difference, assuming the systematic uncertainties are normally distributed, providing evidence of an active non- nu(e) component in the solar flux. The total flux of active 8B neutrinos is determined to be 5.44+/-0.99 x 10(6) cm(-2) s(-1).

B. AHARMIM et al.PHYSICAL REVIEW C 75, 045502 (2007) This article provides the complete description of results from the Phase I data set of the Sudbury Neutrino Observatory (SNO). The Phase I data set is based on a 0.65 kiloton-year exposure of 2 H 2 O (in the following denoted as D 2 O) to the solar 8 B neutrino flux. Included here are details of the SNO physics and detector model, evaluations of systematic uncertainties, and estimates of backgrounds. Also discussed are SNO's approach to statistical extraction of the signals from the three neutrino reactions (charged current, neutral current, and elastic scattering) and the results of a search for a day-night asymmetry in the ν e flux. Under the assumption that the 8 B spectrum is undistorted, the measurements from this phase yield a solar ν e flux of φ(ν e ) = 1.76 6 cm −2 s −1 . The sum of these components provides a total flux in excellent agreement with the predictions of standard solar models. The day-night asymmetry in the ν e flux is found to be A e = 7.0 ± 4.9 (stat.) +1.3 −1.2 % (syst.), when the asymmetry in the total flux is constrained to be zero.

The purpose of this work is to present a simple and inexpensive experiment to study the drainage of a cylindrical vessel. The experimental set up consists of a transparent cylinder and a web cam or a digital camera connected to a computer. The model proposed to explain the results makes use of Bernoulli's equation for real flows that includes energy losses. The experiment allows us to test thoroughly the implication of the model and to extract the relevant parameter associated with the energy losses. The experimental results can be nicely explained by the model, which is a generalization of Torricelli's expression, and clearly illustrate the utility of the extended Bernoulli equation for real fluids.

We studied the motion of a variable mass oscillator. The mass used is a container full of sand that loses sand at a constant rate and hangs from a spring. The spring was suspended from a force sensor connected to a data acquisition system that let us study the evolution of the system. In the underdamped regime we identified three distinct types of behavior for the system, depending on the relation between the energy loss due to the exit of mass and the energy loss through friction. The experimental results are well described by both the numerical solution to the equations of motion and our model, which makes it simple to predict the different types of behavior and to assess the relevant physical parameters involved in the dynamics of this system.

We present a set of experiments spanning a broad range of areas of physics that can be carried out using either a digital camera or a web cam. Among them we study the trajectories of water jets, the profile of hanging chains and caustic figures produced by the reflection of light on mirrors of different shapes. This pool of projects shares a common methodological approach and allows for a simple quantitative comparison between theory and experimental results. Since digital cameras are comparatively lowcost laboratory equipment and have become progressively more available, many schools and colleges with limited experimental facilities may benefit from the very costeffective and challenging projects presented here.

We investigate the anharmonicity of a large amplitude pendulum and develop a novel technique to detect the high Fourier components as a function of the amplitude for large amplitudes close to 180°. The technique involves doing a Fourier analysis on each half-cycle of the amplitude versus time. The presence of the third and fifth harmonics is detected and the variations of the corresponding Fourier coefficients with amplitude are studied. The experimental setup is inexpensive and simple to implement.