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M. Wilking

Publications and source records attributed to M. Wilking.

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Design, construction, and operation of a 30-ton Water-based Liquid scintillator detector at Brookhaven National Laboratory

Water-based Liquid Scintillator (WbLS) was proposed over a decade ago as a novel detector medium that might allow the separation and tuning of the relative ratio of the Cherenkov and scintillation signals. A detector employing this technology could support large-scale neutrino detection over both the GeV and MeV energy regimes, while its metal-loading capability could provide an effective means of neutron tagging. WbLS is attractive for two reasons. It can be deployed in very large detectors. It also allows in-situ tuning of the scintillator concentration, and hence the ratio of Cherenkov to scintillation light. Neither pure water Cherenkov detectors nor conventional liquid scintillator detectors offer this capability. At Brookhaven National Laboratory (BNL), two prototypes have been built for understanding WbLS properties and stability, with masses of 1-ton and 30-ton, respectively. We present here the 30-ton prototype detector design, installation, and initial operation including the real-time observation of a transient optical response during the staged scintillator injection. Results from the analysis of data collected in the two detectors will follow in separate publications.

physics.ins-det

Measurement of Light Yield Response of Gd-compatible Water-based Liquid Scintillator with the Brookhaven 1-ton testbed

The Water-based Liquid Scintillator (WbLS) enables hybrid detection by combining scintillation and Cherenkov signals, providing superior event reconstruction capabilities compared to conventional neutrino detectors. We measured the light yield of Gd-compatible WbLS at varying concentrations from 0.35\% to 1\% by mass, using cosmic-ray muons in a 1-ton scale detector at BNL. The light yield is measured as (69.16 $\pm$ 6.92) ph / MeV at 0.35\% concentration, which increased to (87.32 $\pm$ 8.73) ph / MeV at 1\%. These results establish a quantitative basis for optimizing future WbLS-based detectors in neutrino physics.

physics.ins-det

Design, construction, and operation of a 1-ton Water-based Liquid scintillator detector at Brookhaven National Laboratory

Water-based liquid scintillators (WbLS) are attractive neutrino detector materials because they allow us to tune the ratio of the Cherenkov and scintillation signals. Using WbLS large-scale neutrino experiments can benefit from both directional reconstruction and enhanced low-energy efficiency. Furthermore, broadening the science capability of such materials by metal doping may be better suited for water based liquid scintillators. We recently constructed and commissioned a 1-ton WbLS detector with good photosensor coverage and a capable data acquisition system. We intend to use this flexible detector system as a testbed for WbLS R&D. In this paper we give an overview of the 1-ton system and provide some early analysis results.

physics.ins-det

Comparisons and challenges of modern neutrino scattering experiments (TENSIONS2016 report)

Over the last decade, there has been enormous effort to measure neutrino interaction cross sections important to oscillation experiments. However, a number of results from modern experiments appear to be in tension with each other, despite purporting to measure the same processes. The TENSIONS2016 workshop was held at University of Pittsburgh July 24-31, 2016 and was sponsored by the Pittsburgh High Energy Physics, Astronomy, and Cosmology Center (PITT-PACC). The focus was on bringing experimentalists from three experiments together to compare results in detail and try to find the source of tension by clarifying and comparing signal definitions and the analysis strategies used for each measurement. A set of comparisons between the measurements using a consistent set of models was also made. This paper summarizes the main conclusions of that work.

hep-ex

Search for the Rare Decay K_{L}\toπ^{0}π^{0}γ

The KTeV E799 experiment has conducted a search for the rare decay $K_{L}\toπ^{0}π^{0}γ$ via the topology $K_{L}\toπ^{0}π^{0}_Dγ$ (where $π^0_D\toγe^+e^-$). Due to Bose statistics of the $π^0$ pair and the real nature of the photon, the $K_{L}\toπ^{0}π^{0}γ$ decay is restricted to proceed at lowest order by the CP conserving direct emission (DE) of an E2 electric quadrupole photon. The rate of this decay is interesting theoretically since chiral perturbation theory predicts that this process vanishes at level $O(p^4)$. Therefore, this mode probes chiral perturbation theory at $O(p^6)$. In this paper we report a determination of an upper limit of $2.43\times 10^{-7}$ (90% CL) for $K_{L}\toπ^{0}π^{0}γ$. This is approximately a factor of 20 lower than previous results.

hep-ex

Observation of the Decay Xi^0 --> Sigma^+ mu^- nu(bar)

The Xi^0 muon semi-leptonic decay has been observed for the first time with nine identified events using the KTeV beam line and detector at Fermilab. The decay is normalized to the Xi^0 beta decay mode and yields a value for the ratio of decay rates of $(1.8^{+0.7}_{-0.5}(stat.)\pm0.2(syst.))\times 10^{-2}$. This is in agreement with the SU(3) flavor symmetric quark model.

hep-ex

Measurements of the Branching Fractions and Decay Distributions for KL->πμνγand KL->πeνγ

We present measurements of R_Kl3rad = Gamma(KL->π\ellνγ; Egcm > 10 MeV)/Gamma(KL->π\ellν), where ell = mu or e, and Egcm is the photon energy in the kaon rest frame. These measurements are based on KL decays collected in 1997 by the KTeV (E832) experiment at Fermilab. With samples of 1385 KL->πμνγand 14221 KL->π\eνγcandidates, we find R_Km3rad = (0.530 +- 0.019)% and R_Ke3rad = (4.942 +- 0.062)%. We also examine distributions of photon energy and lepton-photon angle.

hep-ex