QCD corrections to e+e−→u dˉ s cˉe^+ e^- \to u~\bar d~s~\bar c at Lep 2 and the Next Linear Collider: CC11 at O(\alpha_s)

QCD one-loop corrections to the full gauge invariant set of electroweak diagrams describing the hadronic process $e^+ e^- \to u~\bar d~s~\bar c$ are computed. Four-jet shape variables for $WW$ events are studied at next-to-leading order and the effects of QCD corrections on the determination of the $W$--mass in the hadronic channel at Lep 2 and NLC is discussed. We compare the exact calculation with a ``naive''approach to strong radiative corrections which has been widely used in the literature.Comment: 10 pages, 4 ps figures, requires axodra

The development of passive flow control vortices

Surface flow visualisation and Particle Image Velocimetry (PIV) were used to investigate the flow-field of sub-boundary layer vane vortex generators (VVGs) and steady jet vortex generators (SJVGs) in a separated flow at 20m/s. The vortex generators were mounted on a 2D bump which was situated on the floor of a 350mm by 250mm wind tunnel and had a separation zone on its trailing edge.Surface flow visualisation was used to select VVG spacings and SJVG velocity ratios for effective separation control and investigate surface flow. Instantaneous and mean parameters downstream of the VVG and SJVG were measured non-intrusively using PIV. The instantaneous behaviour of the vortices was assessed using the coherence of a vortex and fluctuations in the location of instantaneous peak vorticity. Coherence is a parameter that was developed in the course of this research and had not been encountered in the literature at the time experiments ceased. The mean behaviour of the vortices was assessed using traditional variables, such as, mean, peak vorticity and its location, diameter and circulation of the vortex. A flat plate VVG study was performed to allow direct comparisons with previous work to be made.It was found that vortices generated by both VVGs and SJVGs were unsteady irrespective of geometry, became incoherent with downstream distance and had an exponential decay in mean peak vorticity. Surface flow visualisation indicated that for multiple VVG configurations the co-rotating configuration with a spacing of 3h effectively minimised separation on the 2D bump. For SJVGs, a velocity ratio of 1.0 was sufficient for separation contro

Interference Effects in Higgs production through Vector Boson Fusion in the Standard Model and its Singlet Extension

Interference effects play an important role in Electroweak Physics. They are responsible for the restoration of unitarity al large energies. When, as is often the case, higher order corrections are only available for some particular subamplitude, interferences need to be carefully computed in order to obtain the best theoretical prediction. In the new proposal to estimate the total Higgs width from the off shell cross section, the interference between the Higgs signal and the background is essential. It has been recently pointed out in gluon fusion that whenever more than one neutral, CP even, scalars are present in the spectrum large cancellations can occur. We extend these studies to Vector Boson Scattering, examining interference effects in the Higgs sector in the Standard Model and its one Higgs Singlet extension

Interference effects in Heavy Higgs production via gluon fusion in the Singlet Extension of the Standard Model

The measurements of the properties of the Higgs boson still leave room for a non minimal scalar sector. Extensions of the Standard Model typically involve multiple neutral Higgs fields which can interfere among themselves. We show that these interference effects can be substantial taking as example the one Higgs Singlet Model, the simplest renormalizable addition to the SM.Comment: Added MH=800 GeV, sin(alpha)=0.2 case; added cross section table; added some references. Conclusions unchange

Vector-Vector scattering at the LHC with two charged leptons and two neutrinos in the final state

A complete parton level analysis of 2l2v2j and 4l2j, l = mu,e production at the LHC is presented, including all processes at order alpha^6, alpha^4*alpha_s^2. The infinite Higgs mass scenario, which is considered as a benchmark for strong scattering theories and is the limiting case for composite Higgs models, and one example of Strongly Interacting Light Higgs models are confronted with the Standard Model light Higgs predictions. This analysis is combined with the results in the lv4j, the ll4j and the 3lv2j channels presented in previous papers, in order to determine whether these alternative Higgs frameworks can be detected as an excess of events in boson--boson scattering.Comment: Version accepted by JHE

Instant messaging an effective way of communication in workplace

The modern workplace is inherently collaborative, and this collaboration relies on effective communication among coworkers. Instant messaging is the multitasking tools of choice most people chatting over IM do other things at the same time.The use of IM in workplace is less intrusive than the use of phone, more immediate than email and has added advantage due to the ability to detect presence.In order for institution to maximize increased business productivity using instant messaging its imperative that organizations define and publish ICT policies, guidelines and regulations.Overall IM boosts business performance by making operations faster, more agile, and more efficient with very little additional cost thus Organizations that deploy IM would reap significant Return on Investment.Institutions should adopt IM meetings which are be more efficient and less prone to straying off topic, because of the relative effort of typing versus talking.Comment: 8 page

Nuclear tau and its potential role in Alzheimer’s disease

Tau protein, found in both neuronal and non-neuronal cells, forms aggregates in neurons that constitutes one of the hallmarks of Alzheimer’s disease (AD). For nearly four decades, research efforts have focused more on tau’s role in physiology and pathology in the context of the microtubules, even though, for over three decades, tau has been localised in the nucleus and the nucleolus. Its nuclear and nucleolar localisation had stimulated many questions regarding its role in these compartments. Data from cell culture, mouse brain, and the human brain suggests that nuclear tau could be essential for genome defense against cellular distress. However, its nature of translocation to the nucleus, its nuclear conformation and interaction with the DNA and other nuclear proteins highly suggest it could play multiple roles in the nucleus. To find efficient tau-based therapies, there is a need to understand more about the functional relevance of the varied cellular distribution of tau, identify whether specific tau transcripts or isoforms could predict tau’s localisation and function and how they are altered in diseases like AD. Here, we explore the cellular distribution of tau, its nuclear localisation and function and its possible involvement in neurodegeneration

Effects of jet algorithms from higher order QCD in W±W^\pm mass determinations at LEP2

We analyse the impact of systematic effects due to the scale dependence of QCD corrections in combination with the use of different jet clustering algorithms in the measurement of the $W^\pm$ mass in the fully hadronic decay mode of $W^+W^-$ pairs produced at LEP2. We consider higher order contributions induced by both virtual and real gluon radiation onto the electroweak CC03 and CC11 channels through ${\cal O}(\alpha_{s})$ at the parton level. We find that the associated uncertainties can be of order 100 MeV, thus competitive with those possibly arising in the non-perturbative regime and indeed above the current experimental estimates.Comment: 16 pages, latex, 4 figures, version to appear in EPJdirect

Pion Compton Scattering in Perturbative QCD

Pion Compton scattering is studied in perturbative QCD for real and space--like initial photons. Different methods for the convolution of the hard amplitude with the pion wave--functions, which have in the past led to conflicting results, are compared.Comment: 9 Pages (18 Figs available through ordinary mail) Late