Muon radiography is a fast growing field in applied scientific research. In recent years, many detector technologies and imaging techniques using the Coulomb scattering and absorption properties of cosmic-ray muons have been developed for the non-des
tructive assay of various structures across a wide range of applications. This work presents the first results that assess the feasibility of using muons to interrogate waste silos within the UK Nuclear Industry. Two such approaches, using different techniques that exploit each of these properties, have previously been published, and show promising results from both simulation and experimental data for the detection of shielded high-Z materials and density variations from volcanic assay. Both detector systems are based on scintillator and photomultiplier technologies. Results from dedicated simulation studies using both these technologies and image reconstruction techniques are presented for an intermediate-sized nuclear waste storage facility filled with concrete and an array of uranium samples. Both results highlight the potential to identify uranium objects of varying thicknesses greater than 5cm within real-time durations of several weeks. Increased contributions from Coulomb scattering within the concrete of the structure hinder the ability of both approaches to resolve objects of 2cm dimensions even with increased statistics. These results are all dependent on both the position of the objects within the facility and the locations of the detectors. Results for differing thicknesses of concrete, which reflect the unknown composition of the structures under interrogation, are also presented alongside studies performed for a series of data collection durations. It is anticipated that with further research, muon radiography in one, or both of these forms, will play a key role in future industrial applications within the UK Nuclear Industry.
The NA62 experiment will begin taking data in 2015. Its primary purpose is a 10% measurement of the branching ratio of the ultrarare kaon decay $K^+ to pi^+ u bar{ u }$, using the decay in flight of kaons in an unseparated beam with momentum 75 GeV
/c.The detector and analysis technique are described here.
The NA48/2 Collaboration at CERN has accumulated and analysed unprecedented statistics of rare kaon decays in the $K_{e4}$ modes: $K_{e4}(+-)$ ($K^pm to pi^+ pi^- e^pm u$) and $K_{e4}(00)$ ($K^pm to pi^0 pi^0 e^pm u$) with nearly one percent backgr
ound contamination. It leads to the improved measurement of branching fractions and detailed form factor studies. New final results from the analysis of 381 $K^pm to pi^pm gamma gamma$ rare decay candidates collected by the NA48/2 and NA62 experiments at CERN are presented. The results include a decay rate measurement and fits to Chiral Perturbation Theory (ChPT) description.
The realization of low-cost instruments with high technical performance is a goal which deserves some efforts in an epoch of fast technological developments: indeed such instruments can be easily reproduced and therefore allow to open new research pr
ograms in several Observatories. We realized a fast optical photometer based on the SiPM technology, using commercially available modules. Using low-cost components we have developed a custom electronic chain to extract the signal produced by a commercial MPPC module produced by Hamamatsu, in order to obtain sub millisecond sampling of the light curve of astronomical sources, typically pulsars. In the early February 2011 we observed the Crab Pulsar at the Cassini telescope with our prototype photometer, deriving its period, power spectrum and shape of its light curve in very good agreement with the results obtained in the past with other instruments.
The branching ratio (BR) for the decay K^+ rightarrow pi^+ u bar{ u} is a sensitive probe for new physics. The NA62 experiment at the CERN SPS will measure this BR to within about 10%. To reject the dominant background from channels with final state
photons, the large-angle vetoes (LAVs) must detect photons of energy as low as 200 MeV with an inefficiency of less than 10^-4, as well as provide energy and time measurements with resolutions of 10% and 1 ns for 1 GeV photons. The LAV detectors make creative reuse of lead glass blocks recycled from the OPAL electromagnetic calorimeter barrel. We describe the mechanical design and challenges faced during construction, the characterization of the lead glass blocks and solutions adopted for monitoring their performance, and the development of front-end electronics to allow simultaneous time and energy measurements over an extended dynamic range using the time-over-threshold technique. Our results are based on test-beam data and are reproduced by a detailed Monte Carlo simulation that includes the readout chain.
We report the measurement of the ratio $Gamma(eta to pi^+pi^-gamma)/Gamma(eta to pi^+pi^-pi^0)$ analyzing a large sample of $phi to eta gamma$ decays recorded with the KLOE experiment at the DA$Phi$NE $e^+ e^-$ collider, corresponding to an integrate
d luminosity of 558 pb$^{-1}$. The $eta to pi^+pi^-gamma$ process is supposed to proceed both via a resonant contribution, mediated by the $rho$ meson, and a non resonant direct term, connected to the box anomaly. The presence of the direct term affects the partial width value. Our result $R_{eta}=Gamma(eta to pi^+ pi^- gamma)/Gamma(eta to pi^+ pi^- pi^0)= 0.1838pm 0.0005_{stat} pm 0.0030_{syst}$ is in agreement with a recent CLEO measurement, which differs by more 3 $sigma$ from the average of previous results.
We have measured the cross section of the radiative process e+e- -> pi+pi-gamma with the KLOE detector at the Frascati phi-factory DAPHNE, from events taken at a CM energy W=1 GeV. Initial state radiation allows us to obtain the cross section for e+e
- -> pi+pi-, the pion form factor |F_pi|^2 and the dipion contribution to the muon magnetic moment anomaly, Delta a_mu^{pipi} = (478.5+-2.0_{stat}+-5.0_{syst}+-4.5_{th}) x 10^{-10} in the range 0.1 < M_{pipi}^2 < 0.85 GeV^2, where the theoretical error includes a SU(3) ChPT estimate of the uncertainty on photon radiation from the final pions. The discrepancy between the Standard Model evaluation of a_mu and the value measured by the Muon g-2 collaboration at BNL is confirmed.
We present a measurement of the slope parameter $alpha$ for the $etato 3pi^{0}$ decay, with the KLOE experiment at the DA$Phi$NE $phi$-factory, based on a background free sample of $sim$ 17 millions $eta$ mesons produced in $phi$ radiative decays. By
fitting the event density in the Dalitz plot we determine $alpha = -0.0301 pm 0.0035,stat;_{-0.0035}^{+0.0022},syst,$. The result is in agreement with recent measurements from hadro- and photo-production experiments.
We update the values of the eta-eta mixing angle and of the eta gluonium content by fitting our measurement R_phi = BR(phi to eta gamma)/ BR(phi to eta gamma) together with several vector meson radiative decays to pseudoscalars (V to P gamma), pseudo
scalar mesons radiative decays to vectors (P to V gamma) and the eta to gamma gamma, pi^0 to gamma gamma widths. From the fit we extract a gluonium fraction of Z^2_G = 0.12 +- 0.04, the pseudoscalar mixing angle psi_P = (40.4 +- 0.6) degree and the phi-omega mixing angle psi_V = (3.32 +- 0.09) degree. Z^2_G and psi_P are fairly consistent with those previously published. We also evaluate the impact on the eta gluonium content determination of future experimental improvements of the eta branching ratios and decay width.
We have studied the phi->a_0(980) gamma process with the KLOE detector at the Frascati phi-factory DAPhNE by detecting the phi->eta pi^0 gamma decays in the final states with eta->gamma gamma and eta->pi^+ pi^- pi^0. We have measured the branching ra
tios for both final states: Br(phi->eta pi^0 gamma)=(7.01 +/- 0.10 +/- 0.20)x10^-5 and (7.12 +/- 0.13 +/- 0.22)x10^-5 respectively. We have also extracted the a_0(980) mass and its couplings to eta pi^0, K^+ K^-, and to the phi meson from the fit of the eta pi^0 invariant mass distributions using different phenomenological models.
