Two Recent Results on B Physics from CDF

Preliminary results from two recent CDF b physics analysis are presented. The first obtains sin(2beta) = 0.79 + 0.41 -0.44 from a measurement of the asymmetry in B0, B0bar to J/psi K_short decays, providing the best direct indication so far that CP invariance is violated in the b sector. The second obtains new results on the parity even (A_0 and A_par) and odd (A_perp) polarization amplitudes from full angular analyses of B0 to J/psi K*0 and B_s to J/psi phi decays.Comment: 8 pages, 4 figures; presented at the 34th Recontres de Moriond, Les Arcs, 1800, France, 13-20 March 199

The Role and Problems of Small Business

Jordens befolkning ökar i snabb takt och stadsodlingar kan vara ett sätt att förse den ökande populationen med mat. Hur byggnadsintegrerade stadsodlingar, med fokus på tak, kan kopplas till hållbarhet undersöks i denna rapport. Den nuvarande situationen i Afrika och Nordamerika undersöks och frågeställningen som besvaras är: Hur skiljer sig prioriteringen av olika dimensioner av hållbarhet vid olika förutsättningar för urbana byggnadsintegrerade odlingar i Afrika och Nordamerika? Vilka aspekter av hållbarhet som kopplas till byggnadsintegrerade stadsodlingar bestäms till ekologiska, sociala och ekonomiska. Stadsodlingar kan också delas in i fyra olika verksamhetsplaner, av vilka institutionella odlingar, kommersiella odlingar och community farms analyseras. Resultatet visar att Afrika och Nordamerika har olika förutsättningar för att stadsodling ska vara en hållbar lösning. Afrika består idag av 1.1 miljarder människor vilket beräknas stiga till 2.4 miljarder år 2050. Klimatet är torrt på de flesta platser och en stor del av befolkningen lever i fattigdom och svält. Nordamerika har ett tempererat klimat med fyra årstider, och befolkningen kommer att ligga på en stabil nivå fram till år 2050. Nordamerika räknas som ett mer utvecklat land, vilket innebär att de ekonomiska förutsättningarna här är större än de är i Afrika. Det finns en större andel stora odlingar i Nordamerika jämfört med Afrika, där odlingarna är mindre till ytan. Det finns också fler exempel på byggnadsintegrerad stadsodling i Nordamerika än i Afrika. Slutsatserna blir att byggnadsintegrerade stadsodlingar har bättre potential att utvecklas i Nordamerika då de kräver en stor investeringskostnad vid anläggning. För att byggnadsintegrerade stadsodlingar ska bli en mer hållbar och utbredd lösning både i Afrika och Nordamerika krävs att anläggningskostnaderna sänks med hjälp av nya tekniker. Community farms och institutionella odlingar prioriterar social hållbarhet medan kommersiella odlingar främst satsar på ekologisk och ekonomisk hållbarhet. Stadsodlingar är och har möjlighet att bli en allt viktigare del i matförsörjningen i städer. Då städerna förtätas minskar tillgänglig odlingsyta och andra lösningar måste användas. Byggnadsintegrerad stadsodling är en hållbar lösning både ekologiskt och socialt, och kan även kostnaderna för en byggnadsintegrerad odling minska kan dessa odlingar vara till stor hjälp för att minska svält och fattigdom. The world population is increasing at a rapid pace and city farms may be a way to provide food to the growing population. How building integrated urban farms, with a focus on roofs, can be linked to sustainability, is examined in this report. The current situation in Africa and North America are examined and the question to be answered is: How does the priority of the dimensions of sustainability vary at different conditions for urban building integrated farms in Africa and North America? The aspects of sustainability linked to building integrated urban farms are determined to be ecological, social and economic. Urban farms can also be divided into four different business types, of which institutional farms, commercial farms and community farms are analyzed. The results show that Africa and North America differ in possibilities for urban farming to be sustainable. Africa currently consists of 1.1 billion people, and this is expected to rise to 2.4 billion in 2050. Climate is dry in most places and a large part of the population lives in poverty and starvation. North America has a colder climate with four seasons, and the population will remain stable until 2050. North America is classified as a more developed area, which means that the economics in this area also are more developed than they are in Africa. There are more large-sized farms in North America than in Africa, and there are also more examples in North America. The conclusions are that building integrated urban cultures have a better potential to develop in North America since they require a large investment expense. For building integrated urban farms to be a more sustainable solution both in Africa and North America requirements are that construction costs need to be lowered. Community farms and institutional cultures prioritize social sustainability while commercial plantations mainly focus on ecological and economic sustainability. Urban farming is and may become an increasingly important part of the food supply in cities. When the cities densify it reduces available spaces for cultivation and other solutions must be used. These types of farms are sustainable solution both economic and social. If the cost of a building integrated farm can reduce these farms may help to reduce hunger and poverty.

Shadowing and Antishadowing in Neutrino Deep Inelastic Scattering

The coherence of multiscattering quark nuclear processes leads to shadowing and antishadowing of the electromagnetic nuclear structure functions in agreement with measurements. This picture leads to substantially different antishadowing for charged and neutral current processes, particularly in anti-neutrino reactions, thus affecting the extraction of the weak-mixing angle $\sin^2\theta_W$.Comment: 4 pages, 1 figure, Prepared for the International Conference on QCD and Hadronic Physics, Beijing, China, June 16-20 200

Family of exactly solvable models with an ultimative quantum paramagnetic ground state

We present a family of two-dimensional frustrated quantum magnets solely based on pure nearest-neighbor Heisenberg interactions which can be solved quasi-exactly. All lattices are constructed in terms of frustrated quantum cages containing a chiral degree of freedom protected by frustration. The ground states of these models are dubbed ultimate quantum paramagnets and exhibit an extensive entropy at zero temperature. We discuss the unusual and extensively degenerate excitations in such phases. Implications for thermodynamic properties as well as for decoherence free quantum computation are discussed

Polygon Exploration with Time-Discrete Vision

With the advent of autonomous robots with two- and three-dimensional scanning capabilities, classical visibility-based exploration methods from computational geometry have gained in practical importance. However, real-life laser scanning of useful accuracy does not allow the robot to scan continuously while in motion; instead, it has to stop each time it surveys its environment. This requirement was studied by Fekete, Klein and Nuechter for the subproblem of looking around a corner, but until now has not been considered in an online setting for whole polygonal regions. We give the first algorithmic results for this important algorithmic problem that combines stationary art gallery-type aspects with watchman-type issues in an online scenario: We demonstrate that even for orthoconvex polygons, a competitive strategy can be achieved only for limited aspect ratio A (the ratio of the maximum and minimum edge length of the polygon), i.e., for a given lower bound on the size of an edge; we give a matching upper bound by providing an O(log A)-competitive strategy for simple rectilinear polygons, using the assumption that each edge of the polygon has to be fully visible from some scan point.Comment: 28 pages, 17 figures, 2 photographs, 3 tables, Latex. Updated some details (title, figures and text) for final journal revision, including explicit assumption of full edge visibilit