Unquenching the Schwinger Model (revised)

We study the quenched and unquenched lattice Schwinger model with Wilson fermions. The lowest non-trivial order of the systematic expansion recently proposed by Sexton and Weingarten is shown to allow good estimates of long distance physics from quenched configurations. Results for the static potential and the lowest bound state mass are presented.Comment: 4 pages, 2 figures, self-unpacking uuencoded compressed postscript Contribution to Lattice 95 [Revision: value corrected on p.3

Approximate actions for dynamical fermions

Recent developments and applications of approximate actions for full lattice QCD are described. We present first results based on the stochastic estimation of the fermion determinant on $12^3\times 24$ configurations at $\beta=5.2$.Comment: 3 pages, Latex, no figures, Contribution to Lattice 97, The XV International Symposium on Lattice Field Theory, Edinburgh 22-26 July 199

The Numerical Estimation of the Error Induced by the Valence Approximation

We describe a systematic expansion for full QCD. The leading term in the expansion gives the valence approximation. The expansion reproduces full QCD if an infinite number of higher terms are included.Comment: 3 pages, latex, no figures, requires espcrc2.sty (included at end) Contribution to Lattice 94 proceeding

The Phase Structure of the Weakly Coupled Lattice Schwinger Model

The weak coupling expansion is applied to the single flavour Schwinger model with Wilson fermions on a symmetric toroidal lattice of finite extent. We develop a new analytic method which permits the expression of the partition function as a product of pure gauge expectation values whose zeroes are the Lee-Yang zeroes of the model. Application of standard finite-size scaling techniques to these zeroes recovers previous numerical results for the small and moderate lattice sizes to which those studies were restricted. Our techniques, employable for arbitrarily large lattices, reveal the absence of accumulation of these zeroes on the real hopping parameter axis at constant weak gauge coupling. The consequence of this previously unobserved behaviour is the absence of a zero fermion mass phase transition in the Schwinger model with single flavour Wilson fermions at constant weak gauge coupling.Comment: 8 pages, 2 figures, insert to figure 2 include

The Structure of the Aoki Phase at Weak Coupling

A new method to determine the phase diagram of certain lattice fermionic field theories in the weakly coupled regime is presented. This method involves a new type of weak coupling expansion which is multiplicative rather than additive in nature and allows perturbative calculation of partition function zeroes. Application of the method to the single flavour Gross-Neveu model gives a phase diagram consistent with the parity symmetry breaking scenario of Aoki and provides new quantitative information on the width of the Aoki phase in the weakly coupled sector.Comment: 9 pages, 1 figure (minor changes) To be published in Phys. Lett.

Action learning as an enabler for successful technology transfer with construction SMEs

There is an increasing demand for construction companies to adopt and use new technologies. At the same time universities are increasingly being called upon to assist with ‘technology transfer’ through positive engagement with industry. However, there is little literature investigating technology transfer from the perspective of small construction companies which make up the overwhelming majority of firms in the sector. This paper contributes to this developing area by providing a literature review of technology transfer and proposing a holistic system required for success. Building upon this review it assesses the potential use of action learning as a means of providing this holistic solution and, in so doing, promoting technology transfer and improving the links between higher education institutions (HEIs) and the construction industry. The assessment is made through a literature review of action learning in construction and an analysis of results from the national Construction Knowledge Exchange (CKE) initiative which uses an action learning methodology to assist HEIs in supporting local construction small and medium-sized enterprises (SMEs). The initial results show that this innovative approach, has been successful in creating synergies between academic and business worlds, helping HEIs to communicate more effectively with businesses and vice versa. However, the results indicate that innovations which small construction companies tend to more successfully adopt are those which can contribute to the business in a quick, tangible fashion, and which can be dovetailed into existing rganisational capabilities. This is found to be in marked contrast to the relevant literature which depict large companies operating in more complex networks, drawing upon them for new tacit and explicit technologies which support more long term, formal technology strategies, and which often complement some form of specialised internal research and development capability. The implication for policy is that any technology transfer initiatives need to appreciate and actively manage the different motivations and capabilities of small and large construction companies to absorb and use new technology

Hidden innovation in the construction and property sectors

The construction and property industries have a poor reputation for innovation. Indeed, this reputation appears to be backed by official statistics which projects these industries as being devoid of innovative activity. However, the reputation is undeserved. Official statistics misrepresent the extent and nature of innovation in these sectors. A closer analysis reveals that much of the innovation that exists in the sector is hidden from conventional measures. By its nature therefore, it is difficult to measure the precise extent of this innovation and disaggregate it from general improvement. This opaqueness strengthens the need for policymakers, practitioners and researchers within, amongst others, the surveying sector to go beyond the visible spectrum of innovation and design and implement appropriate policies, knowledge bases and practices which engage and leverage the hitherto hidden aspects of innovation

Hadronic decay of a vector meson from the lattice

We explore the decay of a vector meson to two pseudoscalar mesons on the lattice with $N_f=2$ flavours of sea quark. Although we are working with quark masses that do not allow a physical decay, we show how the transition rate can be evaluated from the amplitude for $\rho \to \pi \pi$ and from the annihilation component of $\pi \pi \to \pi \pi$. We explore the decay amplitude for two different pion momenta and find consistent results. The coupling strength we find is in agreement with experiment. We also find evidence for a shift in the $\rho$ mass caused by mixing with two pion states.Comment: 13 pages, version as accepted for Physics Letters