Flight evaluation of LORAN-C in the State of Vermont

A flight evaluation of LORAN C as a supplement to existing navigation aids for general aviation aircraft, particularly in mountainous regions of the United States and where VOR coverage is limited was conducted. Flights, initiated in the summer months, extend through four seasons and practically all weather conditions typical of northeastern U.S. operations. Assessment of all the data available indicates that LORAN C signals are suitable as a means of navigation during enroute, terminal and nonprecision approach operations and the performance exceeds the minimum accuracy criteria

Charmonium properties from lattice QCD + QED: hyperfine splitting, J/ψJ/\psi leptonic width, charm quark mass and aμca_{\mu}^c

We have performed the first $n_f = 2+1+1$ lattice QCD computations of the properties (masses and decay constants) of ground-state charmonium mesons. Our calculation uses the HISQ action to generate quark-line connected two-point correlation functions on MILC gluon field configurations that include $u/d$ quark masses going down to the physical point, tuning the $c$ quark mass from $M_{J/\psi}$ and including the effect of the $c$ quark's electric charge through quenched QED. We obtain $M_{J/\psi}-M_{\eta_c}$ (connected) = 120.3(1.1) MeV and interpret the difference with experiment as the impact on $M_{\eta_c}$ of its decay to gluons, missing from the lattice calculation. This allows us to determine $\Delta M_{\eta_c}^{\mathrm{annihiln}}$ =+7.3(1.2) MeV, giving its value for the first time. Our result of $f_{J/\psi}=$ 0.4104(17) GeV, gives $\Gamma(J/\psi \rightarrow e^+e^-)$=5.637(49) keV, in agreement with, but now more accurate than experiment. At the same time we have improved the determination of the $c$ quark mass, including the impact of quenched QED to give $\overline{m}_c(3\,\mathrm{GeV})$ = 0.9841(51) GeV. We have also used the time-moments of the vector charmonium current-current correlators to improve the lattice QCD result for the $c$ quark HVP contribution to the anomalous magnetic moment of the muon. We obtain $a_{\mu}^c = 14.638(47) \times 10^{-10}$, which is 2.5$\sigma$ higher than the value derived using moments extracted from some sets of experimental data on $R(e^+e^- \rightarrow \mathrm{hadrons})$. This value for $a_{\mu}^c$ includes our determination of the effect of QED on this quantity, $\delta a_{\mu}^c = 0.0313(28) \times 10^{-10}$.Comment: Added extra discussion on QED setup, some new results to study the effects of strong isospin breaking in the sea (including new Fig. 1) and a fit stability plot for the hyperfine splitting (new Fig. 7). Version accepted for publication in PR

Generalized optical theorem for reflection, transmission, and extinction of power for electromagnetic fields

We present a generalization of the optical theorem for electromagnetic fields. This result is used to obtain the power extinguished from a field by a scatterer contained in a dielectric half space. Applications to microscopy and tomography are described

Renormalisation of the tensor current in lattice QCD and the J/ψJ/\psi tensor decay constant

Lattice QCD calculations of form factors for rare Standard Model processes such as $B \to K \ell^+ \ell^-$ use tensor currents that require renormalisation. These renormalisation factors, $Z_T$, have typically been calculated within perturbation theory and the estimated uncertainties from missing higher order terms are significant. Here we study tensor current renormalisation using lattice implementations of momentum-subtraction schemes. Such schemes are potentially more accurate but have systematic errors from nonperturbative artefacts. To determine and remove these condensate contributions we calculate the ground-state charmonium tensor decay constant, $f_{J/\psi}^T$, which is also of interest in beyond the Standard Model studies. We obtain $f_{J/\psi}^T(\bar{\text{MS}}, 2\ \mathrm{GeV})=0.3927(27)$ GeV, with ratio to the vector decay constant of 0.9569(52), significantly below 1. We also give $Z_T$ factors, converted to the $\bar{\mathrm{MS}}$ scheme, corrected for condensate contamination. This contamination reaches 1.5\% at a renormalisation scale of 2 GeV (in the preferred RI-SMOM scheme) and so must be removed for accurate results.Comment: 12 pages, version accepted for publication in PR