Results are presented on R&D efforts to design and build large size veto panels, optimized for underground low background experiments, in the most efficient and economical way using commercially available components. A variety of plastic scintillators, photomultiplier tubes, wavelength shifting fibers, and light reflector combinations were tested. Results of these studies and performance of a 2.2 m long panel are presented.

We describe results from a beam test of a telescope consisting of three planes of single-crystal, diamond pixel detectors. This telescope is a prototype for a small-angle luminosity monitor, the Pixel Luminosity Telescope (PLT), for CMS. We recorded the pixel addresses and pulse heights of all pixels over threshold as well as the fast-or signals from all three telescope planes. We present results on the telescope performance including occupancies, pulse heights, fast-or efficiencies and particle tracking. These results show that the PLT design meets all required specifications.

The Pixel Luminosity Telescope (PLT) is a dedicated luminosity monitor, presently under construction and planned for installation during the next CMS opening, for the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). It measures the particle flux in an array of sixteen telescopes each consisting of three layers of pixel diamond detectors. The PLT's single-crystal CVD diamonds are bump-bonded to the PSI46 pixel readout chip - the same readout chip used in the silicon pixel system in CMS. Final hardware and software components have been assembled at CERN. The performance with has been measured this year in beams at the CERN PS, as well as the test beam facility at Fermilab. With respect to charged particle tracking, we also measured the Lorentz angle in a magnetic field at the CERN SPS. We present the results of these studies for the final system.

The Pixel Luminosity Telescope (PLT) is a dedicated luminosity monitor, presently under construction, for the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). It measures the particle flux in several three layered pixel diamond detectors that are aligned precisely with respect to each other and the beam direction. At a lower rate it also performs particle track position measurements. The PLT's mono-crystalline CVD diamonds are bump-bonded to the same readout chip used in the silicon pixel system in CMS. Mono-crystalline diamond detectors have many attributes that make them desirable for use in charged particle tracking in radiation hostile environments such as the LHC. In order to further characterize the applicability of diamond technology to charged particle tracking we performed several tests with particle beams that included a measurement of the intrinsic spatial resolution with a high resolution beam telescope.

We describe the results from a beam test of a telescope consisting of three planes of single-crystal, diamond pixel detectors.This telescope is a prototype for a proposed small-angle luminosity monitor, the Pixel Luminosity Telescope (PLT), for CMS.We recorded the pixel addresses and pulse heights of all pixels over threshold as well as the fast-or signals from all three telescope planes.We present results on the telescope performance including occupancies, pulse heights, fast-or efficiencies and particle tracking.These results show that the PLT design concept is sound and indicate that the project is ready to proceed with the next phase of carrying out a complete system test.

The Pixel Luminosity Telescope (PLT) is a dedicated luminosity monitor, presently under construction, for the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). It measures the particle flux in three layers of pixel diamond detectors that are aligned precisely with respect to each other and the beam direction, utilizing simultaneously performed particle track position measurements. The PLT's single-crystal CVD diamonds are bump-bonded to the PSI46 pixel readout chip - the same readout chip used in the silicon pixel system in CMS. Single-crystal CVD diamond pixel detectors have many attributes that make them desirable for use in charged particle tracking in radiation hostile environments such as the LHC. They are expected to withstand the radiation near the beam pipe over several years at full LHC luminosity with a modest loss of pulse height and no increase of leakage currents. In order to further characterize the applicability of diamond technology to charged particle tracking, the intrinsic spatial resolution of single-crystal CVD diamonds was measured using a high resolution beam telescope developed at the University of Zurich. We present the results of these studies.

Radioactive isotopes produced through cosmic muon spallation are a background for rare-event detection in ν detectors, double-β-decay experiments, and dark-matter searches. Understanding the nature of cosmogenic backgrounds is particularly important for future experiments aiming to determine the pep and CNO solar neutrino fluxes, for which the background is dominated by the spallation production of ^(11)C. Data from the Kamioka liquid-scintillator antineutrino detector (KamLAND) provides valuable information for better understanding these backgrounds, especially in liquid scintillators, and for checking estimates from current simulations based upon MUSIC, FLUKA, and GEANT4. Using the time correlation between detected muons and neutron captures, the neutron production yield in the KamLAND liquid scintillator is measured to be Y_n=(2.8±0.3)×10^(-4) μ^(-1) g^(-1) cm^2. For other isotopes, the production yield is determined from the observed time correlation related to known isotope lifetimes. We find some yields are inconsistent with extrapolations based on an accelerator muon beam experiment.

The MAJORANA collaboration is pursuing the development of the so-called MAJORANA DEMONSTRATOR. The DEMONSTRATOR is intended to perform research and development towards a tonne-scale germanium-based experiment to search for the neutrinoless double-beta decay of Ge-76. The DEMONSTRATOR can also perform a competitive direct dark matter search for light WIMPs in the 1 - 10 GeV/c(2) mass range. It will consist of approximately 60 kg of germanium detectors in an ultra-low background shield located deep underground at the Sanford Underground Laboratory in Lead, SD. The DEMONSTRATOR will also perform background and technology studies, and half of the detector mass will be enriched germanium. This talk will review the motivation, design, technology and status of the Demonstrator.

The Beam Conditions Monitor (BCM) provides fast, relative measurements of particle fluxes for use in the safety systems of CMS. It uses a set of Chemical Vapor Deposited (CVD) diamond diodes. Sudden, order of magnitude changes in the BCM readout issue non-maskable LHC beam aborts. Dangerous irradiation trends on longer timescales translate into automatic detector interlocks and injection inhibit Operators in the LHC beam and CMS detector control room obtain and display real time (1Hz) readout of flux measurements from the BCM subsystem. The beam radiation monitoring system also provides an independent measurement of the beam luminosity. The next generation luminosity detector, called the Pixel Luminosity Telescope (PLT), is based on pixelated monocrystalline diamond detectors. They provide a fast occupancy information and allow particle tracking near the interaction point to distinguish trajectories originating from the proton-proton collision point and those parallel to the beam pipe. We present the use case of diamond detectors for beam radiation monitoring in CMS and first measurements of 150 GeV/c pi(+) particle tracks in three layers of pixelated diamond detectors. The PLT after installation in 2010 will be the largest utilization of diamond instrumentation in High Energy Physics.

We have successfully built and operated a source deployment system for the KamLAND detector. This system was used to position radioactive sources throughout the delicate 1-kton liquid scintillator volume, while meeting stringent material cleanliness, material compatibility, and safety requirements. The calibration data obtained with this device were used to fully characterize detector position and energy reconstruction biases. As a result, the uncertainty in the size of the detector fiducial volume was reduced by a factor of two. Prior to calibration with this system, the fiducial volume was the largest source of systematic uncertainty in measuring the number of antineutrinos detected by KamLAND. This paper describes the design, operation and performance of this unique calibration system.

Full exploitation of the physics potential of a future International Linear Collider will require the use of polarized electron and positron beams. Experiment E166 at the Stanford Linear Accelerator Center (SLAC) has demonstrated a scheme in which an electron beam passes through a helical undulator to generate photons (whose first-harmonic spectrum extended to 7.9MeV) with circular polarization, which are then converted in a thin target to generate longitudinally polarized positrons and electrons. The experiment was carried out with a 1-m-long, 400-period, pulsed helical undulator in the Final Focus Test Beam (FFTB) operated at 46.6GeV. Measurements of the positron polarization have been performed at five positron energies from 4.5 to 7.5MeV. In addition, the electron polarization has been determined at 6.7MeV, and the effect of operating the undulator with a ferrofluid was also investigated. To compare the measurements with expectations, detailed simulations were made with an upgraded version of Geant4that includes the dominant polarization-dependent interactions of electrons, positrons, and photons with matter. The measurements agree with calculations, corresponding to 80% polarization for positrons near 6MeV and 90% for electrons near 7MeV.

The MAJORANA Project, a neutrinoless double-beta decay experiment is described with an emphasis on the choice of Ge-detector configuration.

Received 9 December 2008DOI:https://doi.org/10.1103/PhysRevLett.101.259901©2008 American Physical Society

We present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cb vertical bar and of the parameters rho(2), R-1(1), and R-2(1), which fully characterize the form factors for the B-0 -> D*(-)center dot(+)nu(center dot) decay in the framework of heavy-quark effective field theory. The results, based on a selected sample of about 52 800 B-0 -> D*(-)center dot(+)nu(center dot) decays, recorded by the BABAR detector, are rho(2)=1.157 +/- 0.094 +/- 0.027, R-1(1)=1.327 +/- 0.131 +/- 0.043, R-2(1)=0.859 +/- 0.077 +/- 0.021, and F(1)vertical bar V-cb vertical bar=(34.7 +/- 0.4 +/- 1.0)x10(-3). The first error is the statistical and the second is the systematic uncertainty. Combining these measurements with the previous BABAR measurement of the form factors, which employs a different fit technique on a partial sample of the data, we improve the statistical precision of the result, rho(2)=1.191 +/- 0.048 +/- 0.028, R-1(1)=1.429 +/- 0.061 +/- 0.044, R-2(1)=0.827 +/- 0.038 +/- 0.022, and F(1)vertical bar V-cb vertical bar=(34.4 +/- 0.3 +/- 1.1)x10(-3). Using lattice calculations for the axial form factor F(1), we extract vertical bar V-cb vertical bar=(37.4 +/- 0.3 +/- 1.2 +/-(1.2)(1.4))x10(-3), where the third error is due to the uncertainty in F(1). We also present a measurement of the exclusive branching fraction, B=(4.69 +/- 0.04 +/- 0.34)%.

Using a data sample corresponding to an integrated luminosity of 342 fb(-1) collected with the BABAR detector at the SLAC PEP-II electron-positron storage ring operating at a center-of-mass energy near 10.58 GeV, we measure B(tau(-)--> pi(-)pi(-)pi+nu(tau)(ex.K(S0))=(8.83+/-0.01+/-0.13)%, B(tau(-) -->K(-)pi(-)pi+nu tau(ex.K(S0))=(0.273+/-0.002+/-0.009)%, B(tau(-) -->K(-)pi(-)K+nu tau)=(0.1346+/-0.0010+/-0.0036)%, and B(tau(-) -->K(-)K(-)K+nu tau)=(1.58+/-0.13+/-0.12)x10;{-5}, where the uncertainties are statistical and systematic, respectively. These include significant improvements over previous measurements and a first measurement of B(tau(-) -->K(-)K(-)K+nu tau) in which no resonance structure is assumed. We also report a first measurement of B(tau(-) -->var phi(-)nu tau)=(3.42+/-0.55+/-0.25)x10(-5), a new measurement of B(tau(-) -->var phi K(-)nu tau)=(3.39+/-0.20+/-0.28)x10(-5) and a first upper limit on B(tau(-) -->K(-)K(-)K+nu tau(ex.var phi)).

The KamLAND experiment has determined a precise value for the neutrino oscillation parameter Deltam21(2) and stringent constraints on theta12. The exposure to nuclear reactor antineutrinos is increased almost fourfold over previous results to 2.44 x 10(32) proton yr due to longer livetime and an enlarged fiducial volume. An undistorted reactor nu[over]e energy spectrum is now rejected at >5sigma. Analysis of the reactor spectrum above the inverse beta decay energy threshold, and including geoneutrinos, gives a best fit at Deltam21(2)=7.58(-0.13)(+0.14)(stat) -0.15+0.15(syst) x 10(-5) eV2 and tan2theta12=0.56(-0.07)+0.10(stat) -0.06+0.10(syst). Local Deltachi2 minima at higher and lower Deltam21(2) are disfavored at >4sigma. Combining with solar neutrino data, we obtain Deltam21(2)=7.59(-0.21)+0.21 x 10(-5) eV2 and tan2theta12=0.47(-0.05)+0.06.

An experiment (E166) at the Stanford Linear Accelerator Center has demonstrated a scheme in which a multi-GeV electron beam passed through a helical undulator to generate multi-MeV, circularly polarized photons which were then converted in a thin target to produce positrons (and electrons) with longitudinal polarization above 80% at 6 MeV. The results are in agreement with GEANT4 simulations that include the dominant polarization-dependent interactions of electrons, positrons, and photons in matter.

We present results of a search for the decays $B^0 \to \ell^+\ell^-\gamma$ ($\ell=e$, $\mu$). The search is performed using $320\times 10^{6}$ $B\bar{B}$ pairs collected at the $\Upsilon(4S)$ resonance with the BABAR detector at the PEP-II $B$ Factory at SLAC. We find no significant signal and set the following branching fraction upper limits at the 90% confidence level: $\mathcal{B}(B^0\to e^+e^-\gamma)<1.2\times 10^{-7}$ and $\mathcal{B}(B^0\to \mu^+\mu^-\gamma)<1.5\times 10^{-7}$.