Expression of Interest: The Atmospheric Neutrino Neutron Interaction Experiment (ANNIE)

Neutron tagging in Gadolinium-doped water may play a significant role in reducing backgrounds from atmospheric neutrinos in next generation proton-decay searches using megaton-scale Water Cherenkov detectors. Similar techniques might also be useful in the detection of supernova neutrinos. Accurate determination of neutron tagging efficiencies will require a detailed understanding of the number of neutrons produced by neutrino interactions in water as a function of momentum transferred. We propose the Atmospheric Neutrino Neutron Interaction Experiment (ANNIE), designed to measure the neutron yield of atmospheric neutrino interactions in gadolinium-doped water. An innovative aspect of the ANNIE design is the use of precision timing to localize interaction vertices in the small fiducial volume of the detector. We propose to achieve this by using early production of LAPPDs (Large Area Picosecond Photodetectors). This experiment will be a first application of these devices demonstrating their feasibility for Water Cherenkov neutrino detectors.Comment: Submitted for the January 2014 Fermilab Physics Advisory Committee meetin

Expression of Interest: The Atmospheric Neutrino Neutron Interaction Experiment (ANNIE)

Submitted for the January 2014 Fermilab Physics Advisory Committee meetingSubmitted for the January 2014 Fermilab Physics Advisory Committee meetingSubmitted for the January 2014 Fermilab Physics Advisory Committee meetingSubmitted for the January 2014 Fermilab Physics Advisory Committee meetingNeutron tagging in Gadolinium-doped water may play a significant role in reducing backgrounds from atmospheric neutrinos in next generation proton-decay searches using megaton-scale Water Cherenkov detectors. Similar techniques might also be useful in the detection of supernova neutrinos. Accurate determination of neutron tagging efficiencies will require a detailed understanding of the number of neutrons produced by neutrino interactions in water as a function of momentum transferred. We propose the Atmospheric Neutrino Neutron Interaction Experiment (ANNIE), designed to measure the neutron yield of atmospheric neutrino interactions in gadolinium-doped water. An innovative aspect of the ANNIE design is the use of precision timing to localize interaction vertices in the small fiducial volume of the detector. We propose to achieve this by using early production of LAPPDs (Large Area Picosecond Photodetectors). This experiment will be a first application of these devices demonstrating their feasibility for Water Cherenkov neutrino detectors

Measurements of the Decay KL→e+e−γK_L \to e^+e^-\gamma

The E799-II (KTeV) experiment at Fermilab has collected 83262 $K_L \to e^+e^-\gamma$ events above a background of 79 events. We measure a decay width, normalized to the $K_L \to \pi^0\pi^0\pi^0_D$ (\pi^0 \to \gamma\gamma, \pi^0 to \gamma\gamma, \pi^0_D \to e^+e^-\gamma) decay width, of $\Gamma($K_L \to e^+e^-\gamma$)/\Gamma(K_L \to \pi^0\pi^0\pi^0_D) = (1.3302 \pm 0.0046_{stat} \pm 0.0102_{syst}) \times 10^{-3}$. We also measure parameters of two $K_L \gamma^{\ast}\gamma$ form factor models. In the Bergstrom, Masso, and Singer (BMS) parametrization, we find \caks = -0.517 \pm 0.030_{stat} \pm 0.022_{syst}. We separately fit for the first parameter of the D'Ambrosio, Isidori, and Portoles (DIP) model and find \adip = -1.729 \pm 0.043_{stat} \pm 0.028_{syst}.Comment: 5 pages, 3 figures, submitted to PR

Search for exchange-antisymmetric two-photon states

Atomic two-photon J=0 $\leftrightarrow$J'=1 transitions are forbidden for photons of the same energy. This selection rule is related to the fact that photons obey Bose-Einstein statistics. We have searched for small violations of this selection rule by studying transitions in atomic Ba. We set a limit on the probability $v$ that photons are in exchange-antisymmetric states: $v<1.2\cdot10^{-7}$.Comment: 5 pages, 4 figures, ReVTeX and .eps. Submitted to Phys. Rev. Lett. Revised version 9/25/9

Improved KL->pi e nu Form Factor and Phase Space Integral with Reduced Model Uncertainty

Using the published KTeV sample of 2 million KL-> pi e nu decays and a new form factor expansion with a rigorous bound on higher order terms, we present a new determination of the KL->pi e nu form factor and phase space integral. Compared to the previous KTeV result, the uncertainty in the new form factor expansion is negligible and results in an overall uncertainty in the phase space integral (IKe) that is a factor of two smaller: IKe = 0.15392 +- 0.00048 \.Comment: 3 pages, 2 figures, submitted to PRD Rapid Communicatio

A Search for WIMPs with the First Five-Tower Data from CDMS

We report first results from the Cryogenic Dark Matter Search (CDMS II) experiment running with its full complement of 30 cryogenic particle detectors at the Soudan Underground Laboratory. This report is based on the analysis of data acquired between October 2006 and July 2007 from 15 Ge detectors (3.75 kg), giving an effective exposure of 121.3 kg-d (averaged over recoil energies 10--100 keV, weighted for a weakly interacting massive particle (WIMP) mass of 60 \gev). A blind analysis, incorporating improved techniques for event reconstruction and data quality monitoring, resulted in zero observed events. This analysis sets an upper limit on the WIMP-nucleon spin-independent cross section of 6.6$\times10^{-44}$ cm$^2$ (4.6$\times10^{-44}$ cm$^2$ when combined with previous CDMS Soudan data) at the 90% confidence level for a WIMP mass of 60 \gev. By providing the best sensitivity for dark matter WIMPs with masses above 42 GeV/c$^2$, this work significantly restricts the parameter space for some of the favored supersymmetric models.Comment: 5 pages, 4 figures, submitted to PRL 28 March 200