18463747
THE LIQUID SCINTILLATOR NEUTRINO DETECTOR AND LAMPF NEUTRINO SOURCE
Abstract A search for neutrino oscillations of the type ν μ → ν c has been conducted at the Los Alamos Meson Physics Facility using ν μ from muon decay at rest. Evidence for this transition has been reported previously. This paper discusses in detail the experimental setup, detector operation and neutrino source, including aspects relevant to oscillation searches in the muon decay-at-rest and pion decay in flight channels.
125293645
EXPERIMENTAL STUDY OF HEAVY CHARGED LEPTONS AT PETRA
18317704
Measurement of Tau branching ratios
Using the data accumulated at LEP in 1989 and 1990 with the ALEPH detector, the inclusive and exclusive branching ratios of the τ lepton have been measured assuming lepton universality inZ0 decays. The inclusive branching fractions for the τ decay into one, three, and five charged particles have been determined to be (85.45±0.97)%, (14.35±0.48)%, and (0.10±0.05)%, respectively, in agreement with the world averages. New undetected decay modes are determined to have a branching fraction of less than 2.1% at 95% CL. The measured branching ratios for quasi-exclusive channels are slightly larger than, but consistent with the world averages, except for the modes τ→3 hadrons+vτ andτ→hadron+2π0vτ, which are significantly larger. These latter branching ratios have been found to be (9.5±0.7)% and (10.2±1.1)%, respectively. The sum of all the measured quasi-exclusive branching ratios is (100.4±1.8)%. A fully exclusive analysis of modes with neutral pions shows no evidence for new photonic decay modes with a branching fraction limit of 3.4% at 95% CL.
140089864
Critical current, electro-mechanical properties and specific heat of bronze Nb-3_Sn conductors
125256768
Measurements of the reactions C-12 (electron-neutrino, e-) N-12 (g.s.) and C-12 (electron-neutrino, e-) N*-12
10036888
Measurement of the kaon content of three-prong tau decays.
We present branching fraction measurements of three-prong decays of the [tau][sup [minus]] lepton based on data from the TPC/Two-Gamma detector at SLAC PEP. The decays are classified according to the identities of the charged tracks to give simultaneous measurements of [ital B][[tau][sup [minus]][r arrow][nu][sub [tau]] [ital K][sup [minus]][pi][sup +][pi][sup [minus]]]=0.58[sub [minus]0.13][sup +0.15]% and [ital B][[tau][sup [minus]][r arrow][nu][sub [tau]] [ital K][sup [minus]][ital K][sup +][pi][sup [minus]]]=0.15[sub [minus]0.07][sup +0.09]%, and upper limits of [ital B][[tau][sup [minus]][r arrow][nu][sub [tau]][pi][sup [minus]][ital K][sup +][pi][sup [minus]]][lt]0.25%, [ital B][[tau][sup [minus]][r arrow][nu][sub [tau]] [ital K][sup [minus]][pi][sup +][ital K][sup [minus]]][lt]0.09%, and [ital B][[tau][sup [minus]][r arrow][nu][sub [tau]] [ital K][sup [minus]][ital K][sup +][ital K][sup [minus]]][lt]0.21%, where additional neutrals may be present in each case. The branching fractions are normalized to the world average three-prong topological branching fraction and there is an estimated 20% systematic error in addition to the listed statistical errors. We find the mass distributions in the [ital K][sup [minus]][pi][sup +][pi][sup [minus]] decay are consistent with [ital K][sub 1] dominance, and obtain branching fractions of [ital B][[tau][sup [minus]][r arrow][nu][sub [tau]] [ital K][sub 1][sup [minus]](1270)]=0.41[sub [minus]0.35][sup +0.41]% and [ital B][[tau][sup [minus]][r arrow][nu][sub [tau]] [ital K][sub 1][sup [minus]](1400)]=0.76[sub [minus]0.33][sup +0.40]%.
121634492
Lateral shower profiles in a lead/scintillating fiber calorimeter
Abstract The lateral profile of the energy deposition in a prototype of a lead and scintillating fiber calorimeter, constructed in the framework of the LAA project at CERN, has been measured for both electromagnetic and hadronic showers in the energy range from 5 to 150 GeV. The distributions are well described by analytic functions whose parameters allow one to determine the radial scaling of the shower development. In the electromagnetic case, the data are compared to Monte Carlo calculations. Estimates of the lateral leakage outside of the detector are made as well as calculations of the average π 0 content of hadronic showers and event-to-event fluctuations in this electromagnetic component. A method is developed whereby knowledge of the hadronic shower profile can be used to determine the relative calibration constants of neighboring towers in such a calorimeter.
119228154
Full halo coronal mass ejections: Do we need to correct the projection effect in terms of velocity?
[1] The projection effect is one of the biggest obstacles in learning the real properties of coronal mass ejections (CMEs) and forecasting their geoeffectiveness. To evaluate the projection effect, 86 full halo CMEs (FHCMEs) listed in the Coordinated Data Analysis Workshop CME catalog from 1 March 2007 to 31 May 2012 are investigated. By applying the Graduated Cylindrical Shell model, we obtain the deprojected values of the propagation velocity, direction, and angular width of these FHCMEs and compare them with the projected values measured in the plane-of-sky. Although these CMEs look full halo in the view angle of SOHO, it is found that their propagation directions and angular widths could vary in a large range, implying projection effect is a major reason causing a CME being halo, but not the only one. Furthermore, the comparison of the deprojected and projected velocities reveals that most FHCMEs originating within 45° of the Sun-Earth line with a projected speed slower than 900 km s−1 suffer from large projection effect, while the FHCMEs originating far from the vicinity of solar disk center or moving faster than 900 km s−1have small projection effect. Thus, for the latter class of FHCMEs, it is not necessary to correct the measured velocities.
14445704
The Palo Verde reactor neutrino experiment a test for long baseline neutrino oscillations
Our collaboration has installed a long baseline neutrino oscillation experiment at the Palo Verde Nuclear Generating Station in Arizona. 12 tons of Gd loaded liquid scintillator, in a segmented detector, are used to search for νe ↔ νx oscillations at 740 m distance to three reactors. The anti-neutrino capture on the proton serves as detection reaction. The experiment is expected to reach a sensitivity of Δm2 > 1.3 · 10−3 eV2 and sin22Θ > 0.1. Our range of sensitivity is tuned to test the νμ ↔ νe solution of the atmospheric neutrino anomaly.
119818790
The L3 database system
Abstract The database system developed for the L3 experiment at the CERN large electron-positron (LEP) collider is described. The solution chosen has two components: a FORTRAN package (DBL3) and a system of distributed servers and data (L3DBSM). DBL3 provides basic database functions supplemented by facilities specific to high-energy physics experiments. The L3DBSM system, operational since the start of LEP data taking, has handled efficiently several hundred Mbytes of data over three different systems (VAX/VMS, IBM VM/CMS, Apollo Aegis SR10.x) and at eight different sites.
118409330
Unambiguous determination of the neutrino mass hierarchy using reactor neutrinos
Determination of the neutrino mass hierarchy in a reactor neutrino experiment at the medium baseline is discussed. Observation of the interference effects between the Delta m(31)(2) and Delta m(32)(2) oscillations enables a relative measurement independent of the knowledge of the absolute mass-squared difference. With a 20 kton liquid scintillator detector of the 3%/root E (MeV) energy resolution, the Daya Bay II experiment at a baseline of similar to 50 km from reactors of total thermal power 36 GW can determine the mass hierarchy at a confidence level of Delta chi(2)(MH) similar to (10 divided by 12) (3 divided by 3.5 sigma) in six years after taking into account the real spatial distribution of reactor cores. We show that the unknown residual energy nonlinearity of the liquid scintillator detector has limited impact on the sensitivity due to the self-calibration of small oscillation peaks. Furthermore, an extra increase of Delta chi(2)(MH) similar or equal to 4(9) can be obtained, by including the precise measurement of the effective mass-squared difference Delta m(mu mu)(2) of expected relative error 1.5% (1%) from ongoing long-baseline muon neutrino disappearance experiments. The sensitivities from the interference and from absolute measurements can be cross-checked. When combining these two, the mass hierarchy can be determined at a confidence level of Delta chi(2)(MH) similar to (15 divided by 20) (4 sigma) in six years.