Rare B and strange decays

Several deviations from the Standard Model predictions have been recently observed in the decays mediated by $b \rightarrow s l^+ l^-$ transitions. These could be pointing towards new vector-current contributions or could be explained by underestimated charm-loop effects. New results from an LHCb Run 1 $B^+\rightarrow K^+ \mu^+ \mu^-$ analysis that includes the decays via intermediate charm- resonances are discussed. Also, new results from the fully leptonic rare modes searches are presented. This includes the latest Run 1 and Run 2 $B^0_{(s)} \rightarrow \mu^+ \mu^-$ analysis from LHCb where the $B^0_{s} \rightarrow \mu^+ \mu^-$ candidates are used to determine the effective lifetime of the $B^0_{s} \rightarrow \mu^+ \mu^-$ decays - a pioneering result that in the future will solve the current ambiguity in the (pseudo-)scalar contributions

Failure of the adiabatic criterion, structure and coherence in the low energy excitation of helium atoms by helium ions

Producing optical excitations by low energy ion atom and ion molecule collision

'Noise trader risk' and Bayesian market making in FX derivatives: rolling loaded dice?

ABSTRACT This paper develops and simulates a model of a Bayesian market maker who transacts with noise and position traders in derivative markets. The impact of noise trading is examined relative to price determination in FX futures, noise transmission from futures to options, and risk-management behaviour linking the two markets. The model simulations show noise trading in futures results in wider bid–ask spreads, increased price volatility, and greater variation in hedging costs. Above all, the Bayesian market maker manages price-risk by trend chasing not for speculative purposes, but to avoid being caught on the wrong side of the market. The pecuniary effects from this risk-management strategy suggest that noise trading tends to constrain the market maker’s capacity to arbitrage; particularly when the underlying price is mean averting as opposed to a Martingale and trading sessions exhibit significant price volatility. Copyright r 2008 John Wiley & Sons, Ltd. Copyright r 2008 John Wiley & Sons, Ltd.Noise trading; market making; FX derivatives; Bayesian agent; noise transmission

A Human View Model for Socio-Technical Interactions

The Human View was developed as an additional architectural viewpoint to focus on the human part of a system. The Human View can be used to collect and organize data in order to understand how human operators interact and impact the other elements of a system. This framework can also be used to develop a model to describe how humans interact with each other in network enabled systems. These socio-technical interactions form the foundation of the emerging area of Human Interoperability. Human Interoperability strives to understand the relationships required between human operators that impact collaboration across networked environments, including the effect of belonging to different organizations. By applying organizational relationship concepts from network theory to the Human View elements, and aligning these relationships with a model developed to identify layers of coalition interoperability, the conditions for different levels for Human Interoperability for network enabled systems can be identified. These requirements can then be captured in the Human View products to improve the overall network enabled system

Optical radiation from the interaction of energetic atoms, ions, electrons, and photons with surfaces

Heavy particle, electron, and UV photon bombardment of solid surfaces has been recently observed to result in the emission of infrared, visible, and ultraviolet radiation. This effect occurs over a wide range of incident projectile energies. Line radiation arising from transitions between discrete atomic or molecular levels may be attributed to the decay of excited particles which have been sputtered or electronically/chemically desorbed from the surface. Broadband continuum radiation, which is also observed, is believed to arise either from fluorescence of the near surface bulk or from the radiative decay of desorbed excited clusters. Spacecraft, in the ambient near Earth environment, are subject to such bombardment. The dynamics of energetic particle and photon beam interactions with surfaces which lead to surface erosion and glow phenomena will be treated. In addition, projected experimental and theoretical studies of oxygen and nitrogen beam surface interactions on materials characteristic of spacecraft surfaces will be discussed

Mass conservation above slopes in the regional atmospheric modelling system (RAMS)

This paper examines the mass balance in calculations with the Regional Atmospheric Modelling System (RAMS). An error is pointed out that concerns the calculation of the surface fluxes on slopes. This error affects all the prognostic variables in RAMS when sloping terrain is involved. Here we explain how the error can be corrected. To study the impact of the error, we compared simulations with the uncorrected and corrected model. The model contains C

Ultrafast Dynamics of Interfacial Electric Fields in Semiconductor Heterostructures Monitored by Pump-Probe Second Harmonic Generation

We report first measurements of the ultrafast dynamics of interfacial electric fields in semiconductor multilayers using pump-probe second harmonic generation (SHG). A pump beam was tuned to excite carriers in all layers of GaAs/GaSb and GaAs/GaSb/InAs heterostructures. Further carrier dynamics manifests itself via electric fields created by by charge separation at interfaces. The evolution of interfacial fields is monitored by a probe beam through the eletric-field-induced SHG signal. We distinguish between several stages of dynamics originating from redistribution of carriers between the layers. We also find a strong enhancement of the induced electric field caused by hybridization of the conduction and valence bands at the GaSb/InAs interface.Comment: 4 pages + 2 fig