A burst of eight neutrino events preceding the optical detection of the supernova in the Large Magellanic Cloud has been observed in a large underground water Cherenkov detector. The events span an interval of 6 s and have visible energies in the range 20-40 MeV.

The Double Chooz Experiment presents an indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. An observed-to-predicted ratio of events of 0.944 ± 0.016 (stat) ± 0.040 (syst) was obtained in 101 days of running at the Chooz Nuclear Power Plant in France, with two 4.25 GW th reactors. The results were obtained from a single 10 m 3 fiducial volume detector located 1050 m from the two reactor cores. The reactor antineutrino flux prediction used the Bugey4 flux measurement after correction for differences in core composition. The deficit can be interpreted as an indication of a non-zero value of the still unmeasured neutrino mixing parameter sin 2 2θ13. Analyzing both the rate of the prompt positrons and their energy spectrum we find sin 2 2θ13= 0.086 ± 0.041 (stat) ±0.030 (syst), or, at 90% CL, 0.017 < sin 2 2θ13 < 0.16. We report first results of a search for a non-zero neutrino oscillation [1] mixing angle, θ 13 , based on reactor antineutrino disappearance. This is the last of the three neutrino oscillation mixing angles [2,3] for which only upper limits [4,5] are available. The size of θ 13 sets the required sensitivity of long-baseline oscillation experiments attempting to measure CP violation in the neutrino sector or the mass hierarchy.In reactor experiments [6,7] addressing the disappearance ofν e , θ 13 determines the survival probability of electron antineutrinos at the "atmospheric" squaredmass difference, ∆m 2 atm . This probability is given by:where L is the distance from reactor to detector in meters and E the energy of the antineutrino in MeV. The full formula can be found in Ref.[1]. Eq. 1 provides a direct way to measure θ 13 since the only additional input is the well measured value of |∆m 2 atm | = (2.32Other running reactor experiments [9,10] are using the same technique.Electron antineutrinos of < 9 MeV are produced by reactors and detected through inverse beta decay (IBD): ν e + p → e + + n. Detectors based on hydrocarbon liquid scintillators provide the free proton targets. The IBD signature is a coincidence of a prompt positron signal followed by a delayed neutron capture. We present here our first results with a detector located ∼ 1050 m from the two 4.25 GW th thermal power reactors of the Chooz Nuclear Power Plant and under a 300 MWE rock overburden. The analysis is based on 101 days of data including 16 days with one reactor off and one day with both reactors off.The antineutrino flux of each reactor depends on its thermal power and, for the four main fissioning isotopes, 235 U, 239 Pu, 238 U, 241 Pu, their fraction of the total fuel content, their energy released per fission, and their fission and capture cross-sections. The fission rates and associated errors were evaluated using two predictive and complementary reactor simulation codes: MURE [17,18] and DRAGON [19]. This allowed a study of the sensitivity to the important reactor parameters (e.g.. thermal power, boron concentration, temperatures and densities). The quality of these simulations...

Based on the full BABAR data sample, we report improved measurements of the ratios RðDÞ ¼ BðB ! D À Þ=BðB ! D' À ' Þ and RðD Ã Þ ¼ BðB ! D Ã À Þ=BðB ! D Ã ' À ' Þ, where ' refers to either an electron or muon. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure RðDÞ ¼ 0:440 AE 0:058 AE 0:042 and RðD Ã Þ ¼ 0:332 AE 0:024 AE 0:018, which exceed the standard model expectations by 2:0 and 2:7, respectively. Taken together, the results disagree with these expectations at the 3:4 level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model. Kinematic distributions presented here exclude large portions of the more general type III two-Higgs-doublet model, but there are solutions within this model compatible with the results.

Based on the full BABAR data sample, we report improved measurements of the ratios R(D(*))=B(B[over ¯]→D(*)τ(-)ν[over ¯](τ))/B(B[over ¯]→D(*)ℓ(ℓ)(-)ν[over ¯](ℓ)), where ℓ is either e or μ. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D)=0.440±0.058±0.042 and R(D(*))=0.332±0.024±0.018, which exceed the standard model expectations by 2.0σ and 2.7σ, respectively. Taken together, our results disagree with these expectations at the 3.4σ level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.

The BABAR Collaboration BABAR, the detector for the SLAC PEP-II asymmetric e + e − B Factory operating at the Υ (4S) resonance, was designed to allow comprehensive studies of CP -violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagnetic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems , VME-and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.