Results from HARP and their implications for neutrino physics

Recent results from the HARP experiment on the measurements of the double-differential production cross-section of pions in proton interactions with beryllium, carbon and tantalum targets are presented. These results are relevant for a detailed understanding of neutrino flux in accelerator neutrino experiments MiniBooNE/SciBooNE, for a better prediction of atmospheric neutrino fluxes as well as for an optimization of a future neutrino factory design.Comment: Presented at the XLIInd Rencontres de Moriond on Electroweak Interactions and Unified Theorie

The Introduced Fishes, Game Birds, and Game and Fur-Bearing Mammals of Utah

For a number of years wildlife workers have realized the importance of the past histories of introduced species. Emphasis in recent years has been directed toward introductions because of the tremendous hunting and fishing pressures. Yearly increases in numbers of hunters and fishermen have been noted in Utah for the past forty years. It is hoped that this compilation of the histories of the introduced game and fish species of Utah will be of value to sportsmen and wildlife managers alike in planning future introductions. The material included in this paper was obtained from United States Government reports, Utah Territorial reports, Utah State reports, newspapers and periodicals, personal interviews, and wardens\u27 questionaires

Social Spaces of Research Communication: Investigating atmospheres in zones of trade

The roots of the ‘contentious’ relationship between science and society in the United Kingdom are frequently attributed to poor communication, if there is any communication at all, between academic researchers and various publics. This research explores how and why researchers working in various fields of science are practicing diverse roles in the process of research communication beyond academia. The aims of the research were threefold. First, it aimed to capture researchers’ views on their diverse practices in communication of their research beyond academia and whether these reflected social spaces and associated atmospheres in which they were working. The second aim was to investigate the role of university boundary spaces (communications office, knowledge transfer/ business engagement, science outreach) in the communicative practices. The third aim was to ascertain how the recently integrated ‘impact’ component within the UK national Research Evaluation Framework (REF) may influence communication practices of researchers. In order to address these aims, a qualitative investigation was conducted based predominantly on semi-structured interviews and documentary analysis. The research uses a qualitative methodology involving interviews with a purposely selected sample of relevant academic or academically related actors, mainly selected from a University Institution which forms the case study for this research. Research communication beyond academia is found to be a diverse and contingent process constituted through interactions that are concurrently tangible and ephemeral between certain human and non-human actors. Researchers engage in a variety of activities for the purposes of research communication which are contingent on the interactions between animate and inanimate actors in the social spaces where engagement events occur. These interactions often rendered engagement spaces as trading zones, identified according to the outcomes for all the animate and inanimate actors involved. At the university level, there are boundary spaces which coordinate the formation of trading zones between researchers and publics; where research communication occurs through relations-focused and transactions-focused practices. The introduction of the ‘impact’ component within the latest version of the UK research evaluation framework can potentially lead to the narrowing of engagement practices due to valuation that is placed on the framework criteria. The thesis makes an original contribution by demonstrating the value of an interdisciplinary approach combining theories and methods from social geography and other fields of research to the public understanding of science, public engagement with science and science communication. Furthermore, it provides new insights on the ways that researchers view their practices of research communication and how these relate to institutional and societal contexts in which they work

From Popov-Fedotov trick to universal fermionization

We show that Popov-Fedotov trick of mapping spin-1/2 lattice systems on two-component fermions with imaginary chemical potential readily generalizes to bosons with a fixed (but not limited) maximal site occupation number, as well as to fermionic Hamiltonians with various constraints on the site Fock states. In a general case, the mapping---fermionization---is on multi-component fermions with many-body non-Hermitian interactions. Additionally, the fermionization approach allows one to convert large many-body couplings into single-particle energies, rendering the diagrammatic series free of large expansion parameters; the latter is essential for the efficiency and convergence of the diagrammatic Monte Carlo method.Comment: 4 pages, no figures (v2 contains some improvements; the most important one is the generic complex chemical potential trick for spins/bosons

Is the function field of a reductive Lie algebra purely transcendental over the field of invariants for the adjoint action?

Let $k$ be a field of characteristic zero, let $G$ be a connected reductive algebraic group over $k$ and let $\mathfrak{g}$ be its Lie algebra. Let $k(G)$, respectively, $k(\mathfrak{g})$, be the field of $k$-rational functions on $G$, respectively, $\mathfrak{g}$. The conjugation action of $G$ on itself induces the adjoint action of $G$ on $\mathfrak{g}$. We investigate the question whether or not the field extensions $k(G)/k(G)^G$ and $k(\mathfrak{g})/k(\mathfrak{g})^G$ are purely transcendental. We show that the answer is the same for $k(G)/k(G)^G$ and $k(\mathfrak{g})/k(\mathfrak{g})^G$, and reduce the problem to the case where $G$ is simple. For simple groups we show that the answer is positive if $G$ is split of type ${\sf A}_{n}$ or ${\sf C}_n$, and negative for groups of other types, except possibly ${\sf G}_{2}$. A key ingredient in the proof of the negative result is a recent formula for the unramified Brauer group of a homogeneous space with connected stabilizers. As a byproduct of our investigation we give an affirmative answer to a question of Grothendieck about the existence of a rational section of the categorical quotient morphism for the conjugating action of $G$ on itself. The results and methods of this paper have played an important part in recent A. Premet's negative solution (arxiv:0907.2500) of the Gelfand--Kirillov conjecture for finite-dimensional simple Lie algebras of every type, other than ${\sf A}_n$, ${\sf C}_n$, and ${\sf G}_2$.Comment: Final version, 37 pages. To appear in Compositio Mathematica

Superfluid--Insulator Transition in Commensurate One-Dimensional Bosonic System with Off-Diagonal Disorder

We study the nature of the superfluid--insulator quantum phase transition in a one-dimensional system of lattice bosons with off-diagonal disorder in the limit of large integer filling factor. Monte Carlo simulations of two strongly disordered models show that the universality class of the transition in question is the same as that of the superfluid--Mott-insulator transition in a pure system. This result can be explained by disorder self-averaging in the superfluid phase and applicability of the standard quantum hydrodynamic action. We also formulate the necessary conditions which should be satisfied by the stong-randomness universality class, if one exists.Comment: 4 pages, 4 figures. Typo in figure 4 of ver. 3 is correcte

Vortex-Phonon Interaction in the Kosterlitz-Thouless Theory

The "canonical" variables of the Kosterlitz-Thouless theory--fields $\Phi_0({\bf r})$ and $\phi({\bf r})$, generally believed to stand for vortices and phonons (or their XY equivalents, like spin waves, etc.) turn out to be neither vortices and phonons, nor, strictly speaking, {\it canonical} variables. The latter fact explains paradoxes of (i) absence of interaction between $\Phi_0$ and $\phi$, and (ii) non-physical contribution of small vortex pairs to long-range phase correlations. We resolve the paradoxes by explicitly relating $\Phi_0$ and $\phi$ to canonical vortex-pair and phonon variables.Comment: 4 pages, RevTe