Optimising infection prevention and control practice using behavior change: a systematic review

Despite significant investment in infection prevention and control (IPC), there has been little consideration of the effectiveness of behaviour change interventions or the application of behavioural theory (BT) or social marketing (SM) to influence healthcare workers' (HCWs) behaviour and to reduce healthcare associated infection

Continuous-Time Quantum Monte Carlo Algorithm for the Lattice Polaron

An efficient continuous-time path-integral Quantum Monte Carlo algorithm for the lattice polaron is presented. It is based on Feynman's integration of phonons and subsequent simulation of the resulting single-particle self-interacting system. The method is free from the finite-size and finite-time-step errors and works in any dimensionality and for any range of electron-phonon interaction. The ground-state energy and effective mass of the polaron are calculated for several models. The polaron spectrum can be measured directly by Monte Carlo, which is of general interest.Comment: 5 pages, 4 figures, published versio

Simply Modeling Meson HQET

A simple relativistic model of heavy-quark-light-quark mesons is proposed. In an expansion in inverse powers of the heavy quark mass we find that all zeroth and first order heavy quark symmetry relations are satisfied. The main results are: - the difference between the meson mass and the heavy quark mass plays a significant role even at zeroth order; - the slope of the Isgur-Wise function at the zero recoil point is typically less than $-1$; - the first order correction to the pseudoscalar decay constant is large and negative; - the four universal functions describing the first order corrections to the semileptonic decay form factors are small; - these latter corrections are quite insensitive to the choice of model parameters, and in particular to the effects of hyperfine mass splitting.Comment: 17 pages, LaTeX, 3 LaTeX figures in separate file, UTPT-92-16. This is the version published long ago but not previously archive

The Deconfinement Phase Transition in One-Flavour QCD

We present a study of the deconfinement phase transition of one-flavour QCD, using the multiboson algorithm. The mass of the Wilson fermions relevant for this study is moderately large and the non-hermitian multiboson method is a superior simulation algorithm. Finite size scaling is studied on lattices of size $8^3\times 4$, $12^3\times 4$ and $16^3\times 4$. The behaviours of the peak of the Polyakov loop susceptibility, the deconfinement ratio and the distribution of the norm of the Polyakov loop are all characteristic of a first-order phase transition for heavy quarks. As the quark mass decreases, the first-order transition gets weaker and turns into a crossover. To investigate finite size scaling on larger spatial lattices we use an effective action in the same universality class as QCD. This effective action is constructed by replacing the fermionic determinant with the Polyakov loop identified as the most relevant Z(3) symmetry breaking term. Higher-order effects are incorporated in an effective Z(3)-breaking field, $h$, which couples to the Polyakov loop. Finite size scaling determines the value of $h$ where the first order transition ends. Our analysis at the end - point, $h_{ep}$, indicates that the effective model and thus QCD is consistent with the universality class of the three dimensional Ising model. Matching the field strength at the end point, $h_{ep}$, to the $\kappa$ values used in the dynamical quark simulations we estimate the end point, $\kappa_{ep}$, of the first-order phase transition. We find $\kappa_{ep}\sim 0.08$ which corresponds to a quark mass of about 1.4 GeV .Comment: LaTex, 25 pages, 18 figure

Computation of the Heavy-Light Decay Constant using Non-relativistic Lattice QCD

We report results on a lattice calculation of the heavy-light meson decay constant employing the non-relativistic QCD approach for heavy quark and Wilson action for light quark. Simulations are carried out at $\beta=6.0$ on a $16^3\times 48$ lattice. Signal to noise ratio for the ground state is significantly improved compared to simulations in the static approximation, enabling us to extract the decay constant reliably. We compute the heavy-light decay constant for several values of heavy quark mass and estimate the magnitude of the deviation from the heavy mass scaling law $f_{P} \sqrt{m_{P}} = const$. For the $B$ meson we find $f_{B} = 171\pm 22^{+19}_{-45}$ MeV, while an extrapolation to the static limit yields $f_{B}^{static}$ = $297\pm 36^{+15}_{-30}$ MeV.Comment: 34 pages in LaTeX including 10 figures using epsf.sty, uuencoded-gziped-shar format, HUPD-940

Variational Worldline Approximation for the Relativistic Two-Body Bound State in a Scalar Model

We use the worldline representation of field theory together with a variational approximation to determine the lowest bound state in the scalar Wick-Cutkosky model where two equal-mass constituents interact via the exchange of mesons. Self-energy and vertex corrections are included approximately in a consistent way as well as crossed diagrams. Only vacuum-polarization effects of the heavy particles are neglected. In a path integral description of an appropriate current-current correlator an effective, retarded action is obtained by integrating out the meson field. As in the polaron problem we employ a quadratic trial action with variational functions to describe retardation and binding effects through multiple meson exchange.The variational equations for these functions are derived, discussed qualitatively and solved numerically. We compare our results with the ones from traditional approaches based on the Bethe-Salpeter equation and find an enhanced binding contrary to some claims in the literature. For weak coupling this is worked out analytically and compared with results from effective field theories. However, the well-known instability of the model, which usually is ignored, now appears at smaller coupling constants than in the one-body case and even when self-energy and vertex corrections are turned off. This induced instability is investigated analytically and the width of the bound state above the critical coupling is estimated.Comment: 62 pages, 7 figures, FBS style, published versio