2,338 research outputs found
Bounding the Tau Neutrino Magnetic Moment from Single Photon Searches at LEP
We show that single photon searches at LEP constrain the tau neutrino
magnetic moment to be less than . This bound is
competitive with low energy () single photon searches.Comment: 5 pgs. LaTeX, one reference fixed in revised version,
JHU-TIPAC-940004, UM-TH-94-1
Quantum Scattering from Classical Field Theory
We show that scattering amplitudes between initial wave packet states and
certain coherent final states can be computed in a systematic weak coupling
expansion about classical solutions satisfying initial value conditions. The
initial value conditions are such as to make the solution of the classical
field equations amenable to numerical methods. We propose a practical procedure
for computing classical solutions which contribute to high energy two particle
scattering amplitudes. We consider in this regard the implications of a recent
numerical simulation in classical SU(2) Yang-Mills theory for multiparticle
scattering in quantum gauge theories and speculate on its generalization to
electroweak theory. The generalization of our results to complex trajectories
allows its application to it any wave packet to coherent state transition.
Finally, we discuss the relevance of these results to the issues of baryon
number violation and multiparticle scattering at high energies.Comment: 20 pages, JHU-TIPAC-940003, HUTP-A0/007, Latex, uses prepictex.tex,
pictex.tex, and postpictex.tex (available by ftp from [email protected]) to
produce figure
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Increasing compliance with low tidal volume ventilation in the ICU with two nudge-based interventions: evaluation through intervention time-series analyses
Objectives: Low tidal volume (TVe) ventilation improves outcomes for ventilated patients, and the majority of clinicians state they implement it. Unfortunately, most patients never receive low TVes. âNudgesâ influence decision-making with subtle cognitive mechanisms and are effective in many contexts. There have been few studies examining their impact on clinical decision-making. We investigated the impact of 2 interventions designed using principles from behavioural science on the deployment of low TVe ventilation in the intensive care unit (ICU).
Setting: University Hospitals Bristol, a tertiary, mixed medical and surgical ICU with 20 beds, admitting over 1300 patients per year.
Participants: Data were collected from 2144 consecutive patients receiving controlled mechanical ventilation for more than 1â
hour between October 2010 and September 2014. Patients on controlled mechanical ventilation for more than 20â
hours were included in the final analysis.
Interventions: (1) Default ventilator settings were adjusted to comply with low TVe targets from the initiation of ventilation unless actively changed by a clinician. (2) A large dashboard was deployed displaying TVes in the format mL/kg ideal body weight (IBW) with alerts when TVes were excessive.
Primary outcome measure: TVe in mL/kg IBW.
Findings: TVe was significantly lower in the defaults group. In the dashboard intervention, TVe fell more quickly and by a greater amount after a TVe of 8â
mL/kg IBW was breached when compared with controls. This effect improved in each subsequent year for 3â
years.
Conclusions: This study has demonstrated that adjustment of default ventilator settings and a dashboard with alerts for excessive TVe can significantly influence clinical decision-making. This offers a promising strategy to improve compliance with low TVe ventilation, and suggests that using insights from behavioural science has potential to improve the translation of evidence into practice
Complex Time Solutions with Nontrivial Topology and Multi Particle Scattering in Yang-Mills Theory
A classical solution to the Yang-Mills theory is given a new semiclassical
interpretation in terms of particle scattering. It solves the complex time
boundary value problem, which arises in the semiclassical approximation to a
multi particle transition probability in the one-instanton sector at fixed
energy. The imaginary part of the action of the solution on the complex time
contour and its topological charge obey the same relation as the self-dual
Euclidean configurations. Hence the solution is relevant for the problem of
tunneling with fermion number violation in the electroweak theory. It describes
transitions from an initial state with a smaller number of particles to a final
state with a larger number of particles. The implications of these results for
multi particle production in the electroweak theory are also discussed.Comment: 10 pgs. (LaTeX), JHU-TIPAC-93001
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