Inclusion of non-spherical components of the Pauli blocking operator in (p,p') reactions

We present the first calculations of proton elastic and inelastic scattering in which the Pauli blocking operator contains the leading non-spherical components as well as the usual spherical (angle-averaged) part. We develop a formalism for including the contributions to the effective nucleon-nucleon interaction from the resulting new G-matrix elements that extend the usual two-nucleon spin structure and may not conserve angular momentum. We explore the consequences of parity conservation, time reversal invariance, and nucleon-nucleon antisymmetrization for the new effective interaction. Changes to the calculated cross section and spin observables are small in the energy range from 100 to 200 MeV.Comment: 24 pages, 4 figures, to be published in Physical Review

Gas of self-avoiding loops on the brickwork lattice

An exact calculation of the phase diagram for a loop gas model on the brickwork lattice is presented. The model includes a bending energy. In the dense limit, where all the lattice sites are occupied, a phase transition occuring at an asymmetric Lifshitz tricritical point is observed as the temperature associated with the bending energy is varied. Various critical exponents are calculated. At lower densities, two lines of transitions (in the Ising universality class) are observed, terminated by a tricritical point, where there is a change in the modulation of the correlation function. To each tricritical point an associated disorder line is found.Comment: 19 pages, 6 figures. to appear in J. Phys. A : Math. & Ge

SU(3) vortex-like configurations in the maximal center gauge

A new algorithm for fixing the gauge to (direct) maximal center gauge in SU(N) lattice gauge theory is presented. We check how this method works on SU(3) configurations which are vortex-like, and show how these configurations look like when center projected.Comment: LATTICE99(confine)-3p,5 postscript figure

Writing a Novel with Roma Primary School Children: Tensions in Disrupting Aetonormativity

Story Makers Press (SMP) is a University-based publisher which co-constructs stories with under-represented groups of children in order to diversify representation in children’s literature and disrupt the way adult perceptions of normality pattern children’s literature (aetonormativity). In this paper we analyse six drama and creative writing workshops run by SMP with Czech and Slovak Roma children from an inner city primary school in the north of England to co-construct a story about climate change. Our analysis identifies how in developing the story, the children were often reluctant to draw upon their funds of knowledge relating to their Roma backgrounds, instead Westernising their protagonists and settings. We also explore how the children disrupt aetonormativity by interweaving magical elements into realistic narrative about climate change in order to establish a genre of magical realism. Finally, we identify how this genre of magical realism is problematic when considering stereotypical depictions of Roma characters in children’s literature and how changes were made to our story in light of a critical race theory reading of the first draft. As well as helping SMP to refine its processes, this analysis suggests that minority groups such as Roma need to be able to draw upon more literary representations of Roma in order to shape their creative outputs and that the curriculum needs to focus on developing children’s critical responses to the representation of minority ethnic groups in children’s literature

String breaking with Wilson loops?

A convincing, uncontroversial observation of string breaking, when the static potential is extracted from Wilson loops only, is still missing. This failure can be understood if the overlap of the Wilson loop with the broken string is exponentially small. In that case, the broken string ground state will only be seen if the Wilson loop is long enough. Our preliminary results show string breaking in the context of the 3d SU(2) adjoint static potential, using the L\"uscher-Weisz exponential variance reduction approach. As a by-product, we measure the fundamental SU(2) static potential with improved accuracy and see clear deviations from Casimir scaling.Comment: Lattice2002(topology), AMS-LaTeX v1.2, 3 pages with 2 figures; added reference

Topological properties of full QCD at the phase transition

We investigate the topological properties of the QCD vacuum with 4 flavours of dynamical staggered fermions at finite temperature. To calculate the topological susceptibility we use the field-theoretical method. As in the quenched case, a sharp drop is observed for the topological susceptibility across the phase transition.Comment: LATTICE98(confine

Intimate Partner Violence and Sexual Risk-taking among Men Who Have Sex with Men in South Africa

Objective: A growing body of literature suggests that men who have sex with men (MSM) represent a high risk group for human immunodeficiency virus (HIV) infection in Africa, but are often overlooked in the development of HIV interventions and programming. Little attention has been paid to the presence of intimate partner violence (IPV) among MSM in African settings. This paper examines reporting of IPV among a sample of predominantly white, gay internet-recruited MSM in South Africa and examines associations between IPV and sexual risk-taking.Methods: Internet-using MSM were recruited through selective placement of banner advertisements on Facebook.com. Eligibility criteria were over 18-years-old, residence in South Africa and self-reporting of recent male-male sexual behavior. There were 777 eligible respondents, of which 521 MSM with complete data are included in the final analysis. Ninety percent of the sample reported a White/ European race, and 96% self-identified as gay.Results: The prevalence of IPV, both experienced and perpetrated, was relatively high, with 8% of men reporting having experienced recent physical IPV and 4.5% of men reporting recent experiences of sexual IPV. Approximately 4.5% of MSM reported recently perpetrating physical IPV, while the reporting of perpetration of recent sexual IPV was much lower at 0.45%. Reporting of experiencing and perpetration of physical IPV was significantly associated with race, level of education and reporting recent unprotected anal sex. Reporting of experiencing recent sexual IPV was significantly associated with reported experiences of homophobia.Conclusion: There is a limited amount of data on IPV within same-sex relationships in South Africa, and the results presented here suggest that the prevalence of IPV within this White/European and gay population is cause for concern. Collection of IPV data through surveys administered via social networking sites is feasible and represents a way of reaching otherwise marginalized population groups in IPV research; although in this instance Black Africans and MSM who did not identify as gay were severely under-represented. [West J Emerg Med. 2011;12(3):343-347.

Breaking of the adjoint string in 2+1 dimensions

The roughly linear rise of the potential found between adjoint sources in SU(N) in lattice simulations is expected to saturate into a state of two `gluelumps' due to gluonic screening. We examine this in SU(2) in 2+1 dimensions. Crossover between string-like and broken states is clearly seen by the mixing-matrix technique, using different operators to probe the two states; the breaking behaviour is rather abrupt. Furthermore, we are able to show that both types of operator have a finite overlap with both states; in the case of the Wilson loops the overlap with the broken string is, as predicted, very small.Comment: LaTeX2e, 20 pages, 15 figures with epsfig; uses amstex, amssymb, a4wide; minor change to presentation (notation for operators) onl

Generalizing the Tomboulis-Yaffe Inequality to SU(N) Lattice Gauge Theories and General Classical Spin Systems

We extend the inequality of Tomboulis and Yaffe in SU(2) lattice gauge theory (LGT) to SU(N) LGT and to general classical spin systems, by use of reflection positivity. Basically the inequalities guarantee that a system in a box that is sufficiently insensitive to boundary conditions has a non-zero mass gap. We explicitly illustrate the theorem in some solvable models. Strong coupling expansion is then utilized to discuss some aspects of the theorem. Finally a conjecture for exact expression to the off-axis mass gap of the triangular Ising model is presented. The validity of the conjecture is tested in multiple ways.Comment: 37 pages, 17 figures. v2: comment on an earlier work included after conclusion, figure 2 corrected. v3: the latter half revised significantly with new results and new discussions, the version to appear in Ann. Phys