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Results are reported from a joint analysis of Phase I and Phase II data from the Sudbury Neutrino Observatory. The effective electron kinetic energy threshold used is T eff = 3.5 MeV, the lowest analysis threshold yet achieved with water Cherenkov detector data. In units of 10 6 cm −2 s −1 , the total flux of active-flavor neutrinos from 8 B decay in the Sun measured using the neutral current (NC) reaction of neutrinos on deuterons, with no constraint on the 8 B neutrino energy spectrum, is found to be NC = 5.140 +0.160 −0.158 (stat) +0.132 −0.117 (syst). These uncertainties are more than a factor of 2 smaller than previously published results. Also presented are the spectra of recoil electrons from the charged current reaction of neutrinos on deuterons and the elastic scattering of electrons. A fit to the Sudbury Neutrino Observatory data in which the free parameters directly describe the total 8 B neutrino flux and the energy-dependent ν e survival probability provides a measure of the total 8

The Sudbury Neutrino Observatory (SNO) used an array of 3 He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (ν x ) 8 B solar neutrino flux. This technique is independent of previous methods employed by SNO The Sudbury Neutrino Observatory [1] detects 8 B solar neutrinos through three reactions: charged-current interactions (CC) on deuterons, in which only electron neutrinos participate; neutrino-electron elastic scattering (ES), which are dominated by contributions from electron neutrinos; and neutral-current (NC) disintegration of the deuteron by neutri-

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The Sudbury Neutrino Observatory (SNO) has precisely determined the total active (ν x ) 8 B solar neutrino flux without assumptions about the energy dependence of the ν e survival probability. The measurements were made with dissolved NaCl in the heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 ± 0.27 (stat) ± 0.38 (syst) × 10 6 cm −2 s −1 , in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields ∆m 2 = 7.1 +1.2 −0.6 × 10 −5 eV 2 and θ = 32.5 +2. ES).Only electron neutrinos produce charged-current interactions (CC), while the neutral-current (NC) and elastic scattering (ES) reactions have sensitivity to non-electron flavors. The NC reaction measures the total flux of all active neutrino flavors above a threshold of 2.2 MeV. SNO previously measured the NC rate by observing neutron captures on deuterons, and found that a Standard-Model description with an undistorted 8 B neutrino spectrum and CC, ES, and NC rates due solely to ν e interactions was rejected [2, 3]. This Letter presents measurements of the CC, NC, and ES rates from SNO's dissolved salt phase.The addition of 2 tonnes of NaCl to the kilotonne of heavy water increased the neutron capture efficiency and the associated Cherenkov light. The solution was thoroughly mixed and

Gravitational lensing due to the large-scale distribution of matter in the cosmos distorts the primordial Cosmic Microwave Background (CMB) and thereby induces new, small-scale B -mode polarization. This signal carries detailed information about the distribution of all the gravitating matter between the observer and CMB last scattering surface. We report the first direct evidence for polarization lensing based on purely CMB information, from using the four-point correlations of even-and odd-parity E -and B -mode polarization mapped over ∼ 30 square degrees of the sky measured by the Polarbear experiment. These data were analyzed using a blind analysis framework and checked for spurious systematic contamination using null tests and simulations. Evidence for the signal of polarization lensing and lensing B -modes is found at 4.2σ (stat.+sys.) significance. The amplitude of matter fluctuations is measured with a precision of 27%, and is found to be consistent with the Lambda Cold Dark Matter (ΛCDM) cosmological model. This measurement demonstrates 2 a new technique, capable of mapping all gravitating matter in the Universe, sensitive to the sum of neutrino masses, and essential for cleaning the lensing B -mode signal in searches for primordial gravitational waves.Introduction: As Cosmic Microwave Background (CMB) photons traverse the Universe, their paths are gravitationally deflected by large-scale structures. By measuring the resulting changes in the statistical properties of the CMB anisotropies, maps of this gravitational lensing deflection, which traces large-scale structure, can be reconstructed. Gravitational lensing of the CMB has been detected in the CMB temperature anisotropy in several ways: in the smoothing of the acoustic peaks of the temperature power spectrum [1-3], in cross-correlations with tracers of the large-scale matter distribution [4][5][6][7][8][9][10], and in the four-point correlation function of CMB temperature maps [11][12][13][14].The South Pole Telescope (SPT) collaboration recently reported a detection of lensed polarization using the cross-correlation between maps of CMB polarization and sub-mm maps of galaxies from Herschel/SPIRE [15]. A companion paper to this one has also shown the evidence of the CMB lensing-Cosmic Infrared Background crosscorrelation results using Polarbear data [16], finding good agreement with the SPT measurements. This crosscorrelation is immune to several instrumental systematic effects but the cosmological interpretation of this measurement requires assumptions about the relation of submm galaxies to the underlying mass distribution [17].In this Letter, we present the first direct evidence for gravitational lensing of the polarized CMB using data from the Polarbear experiment. We present power spectra of the lensing deflection field for two four-point estimators using only CMB polarization data, and tests for spurious systematic contamination of these estimators. We combine the two estimators to increase the signal-to-noise of the lensing detection.CMB lens...

We report a measurement of the B-mode polarization power spectrum in the cosmic microwave background (CMB) using the Polarbear experiment in Chile. The faint B-mode polarization signature carries information about the universe's entire history of gravitational structure formation, and the cosmic inflation that may have occurred in the very early universe. Our measurement covers the angular multipole range 500 < < 2100 and is based on observations of an effective sky area of 25 deg 2 with 3. 5 resolution at 150 GHz. On these angular scales, gravitational lensing of the CMB by intervening structure in the universe is expected to be the dominant source of B-mode polarization. Including both systematic and statistical uncertainties, the hypothesis of no B-mode polarization power from gravitational lensing is rejected at 97.2% confidence. The band powers are consistent with the standard cosmological model. Fitting a single lensing amplitude parameter A BB to the measured band powers, A BB = 1.12 ± 0.61(stat) +0.04 −0.12 (sys) ± 0.07(multi), where A BB = 1 is the fiducial wmap-9 ΛCDM value. In this expression, "stat" refers to the statistical uncertainty, "sys" to the systematic uncertainty associated with possible biases from the instrument and astrophysical foregrounds, and "multi" to the calibration uncertainties that have a multiplicative effect on the measured amplitude A BB .

We present the design and characterization of the polarbear experiment. polarbear will measure the polarization of the cosmic microwave background (CMB) on angular scales ranging from the experiment's 3.5 beam size to several degrees. The experiment utilizes a unique focal plane of 1,274 antenna-coupled, polarization sensitive TES bolometers cooled to 250 milliKelvin. Employing this focal plane along with stringent control over systematic errors, polarbear has the sensitivity to detect the expected small scale B-mode signal due to gravitational lensing and search for the large scale B-mode signal from inflationary gravitational waves.polarbear was assembled for an engineering run in the Inyo Mountains of California in 2010 and was deployed in late 2011 to the Atacama Desert in Chile. An overview of the instrument is presented along with characterization results from observations in Chile.